Re-Emergence of Rift Valley Fever in Madagascar

Centers for Disease Control (CDC) Podcasts

2010-05-27

This podcast describes the re-emergence of Rift Valley Fever in Madagascar during two rainy seasons in 2008 and 2009. CDC epidemiologist Dr. Pierre Rollin discusses what researchers learned about the outbreak and about infections in the larger population in Madagascar.  Created: 5/27/2010 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 5/27/2010.

A review of mosquitoes associated with Rift Valley fever virus in Madagascar.

Science.gov (United States)

Tantely, Luciano M; Boyer, Sébastien; Fontenille, Didier

2015-04-01

Rift Valley fever (RVF) is a viral zoonotic disease occurring throughout Africa, the Arabian Peninsula, and Madagascar. The disease is caused by a Phlebovirus (RVF virus [RVFV]) transmitted to vertebrate hosts through the bite of infected mosquitoes. In Madagascar, the first RVFV circulation was reported in 1979 based on detection in mosquitoes but without epidemic episode. Subsequently, two outbreaks occurred: the first along the east coast and in the central highlands in 1990 and 1991 and the most recent along the northern and eastern coasts and in the central highlands in 2008 and 2009. Despite the presence of 24 mosquitoes species potentially associated with RVFV transmission in Madagascar, little associated entomological information is available. In this review, we list the RVFV vector, Culex antennatus, as well as other taxa as candidate vector species. We discuss risk factors from an entomological perspective for the re-emergence of RVF in Madagascar. © The American Society of Tropical Medicine and Hygiene.

A skin test survey of valley fever in Tijuana, Mexico.

Science.gov (United States)

Fredrich, B E

1989-01-01

Results of a study of the prevalence of valley fever among 1128 residents of Tijuana, Baja California are presented. Children from primary and middle schools (n = 497) and adults from technical institutes and maquiladoras (assembly plants) were tested for reaction to both spherulin and coccidioidin during 1985-1986, and they completed a questionnaire containing 23 variables on their socio-environment. Place of residence was mapped. The population sampled is largely middle class. Discriminant analysis indicates the distribution of positive cases is not clustered, nor can it be correlated with geomorphic factors such as mesa tops, canyons, or valley bottoms.

Vertical transmission of Rift Valley Fever Virus without detectable maternal viremia

NARCIS (Netherlands)

Antonis, A.F.G.; Kortekaas, J.A.; Kant-Eenbergen, H.C.M.; Vloet, R.P.M.; Vogel-Brink, A.; Stockhofe, N.; Moormann, R.J.M.

2013-01-01

Rift Valley fever virus (RVFV) is a zoonotic bunyavirus that causes abortions in domesticated ruminants. Sheep breeds exotic to endemic areas are reportedly the most susceptible to RVFV infection. Within the scope of a risk assessment program of The Netherlands, we investigated the susceptibility of

Interventions Against West Nile Virus, Rift Valley Fever Virus, and Crimean-Congo Hemorrhagic Fever Virus: Where Are We?

NARCIS (Netherlands)

Kortekaas, J.A.; Ergonul, O.; Moormann, R.J.M.

2010-01-01

ARBO-ZOONET is an international network financed by the European Commission's seventh framework program. The major goal of this initiative is capacity building for the control of emerging viral vector-borne zoonotic diseases, with a clear focus on West Nile virus, Rift Valley fever virus, and

Seroprevalence of Sheep and Goat Pox, Peste Des Petits Ruminants and Rift Valley Fever in Saudi Arabia.

Science.gov (United States)

Boshra, Hani; Truong, Thang; Babiuk, Shawn; Hemida, Maged Gomaa

2015-01-01

Sheep and goat pox, peste des petits ruminants and Rift Valley fever are important diseases of small ruminant livestock. Sheep and goat pox, along with peste des petits ruminants, are endemic throughout most of Africa, Asia and the Middle East. Whereas Rift Valley fever is endemic in Africa, outbreaks in the Middle East have been reported over the past decade, including the Arabian Peninsula. Saudi Arabia is a major importer of livestock, and understanding the prevalence of these viral infections would be useful for disease control. In this study, sera from sheep and goats were collected from 3 regions in Saudi Arabia. They were evaluated for antibodies specific to sheep and goat pox, peste des petits ruminants and Rift Valley fever by virus neutralization assays. To the best of our knowledge, this is the first study to evaluate the seroprevalence of these viruses in sheep and goats.

Seroprevalence of Sheep and Goat Pox, Peste Des Petits Ruminants and Rift Valley Fever in Saudi Arabia.

Directory of Open Access Journals (Sweden)

Hani Boshra

Full Text Available Sheep and goat pox, peste des petits ruminants and Rift Valley fever are important diseases of small ruminant livestock. Sheep and goat pox, along with peste des petits ruminants, are endemic throughout most of Africa, Asia and the Middle East. Whereas Rift Valley fever is endemic in Africa, outbreaks in the Middle East have been reported over the past decade, including the Arabian Peninsula. Saudi Arabia is a major importer of livestock, and understanding the prevalence of these viral infections would be useful for disease control. In this study, sera from sheep and goats were collected from 3 regions in Saudi Arabia. They were evaluated for antibodies specific to sheep and goat pox, peste des petits ruminants and Rift Valley fever by virus neutralization assays. To the best of our knowledge, this is the first study to evaluate the seroprevalence of these viruses in sheep and goats.

Blood Meal Analysis of Mosquitoes Involved in a Rift Valley fever Outbreak

Science.gov (United States)

Background: Rift Valley fever (RVF) is a zoonosis of domestic ruminants in Africa. Bloodfed mosquitoes collected during the 2006-2007 RVF outbreak in Kenya were analyzed to determine the virus infection status and animal source of the bloodmeals. Bloodmeals from individual mosquito abdomens were sc...

Temperature-sensitive mutations for live-attenuated Rift Valley fever vaccines: Implications from other RNA viruses

Directory of Open Access Journals (Sweden)

Shoko eNishiyama

2015-08-01

Full Text Available Rift Valley fever (RVF is a mosquito-borne zoonotic disease endemic to the African continent. RVF is characterized by high rate of abortions in ruminants and hemorrhagic fever, encephalitis or blindness in humans. RVF is caused by the Rift Valley fever virus (RVFV: genus Phlebovirus, family Bunyaviridae. Vaccination is the only known effective strategy to prevent the disease, but there are no licensed RVF vaccines available for humans. A live-attenuated vaccine candidate derived from the wild-type pathogenic Egyptian ZH548 strain, MP-12, has been conditionally licensed for veterinary use in the United States. MP-12 displays a temperature-sensitive (ts phenotype and does not replicate at 41oC. The ts mutation limits viral replication at a specific body temperature and may lead to an attenuation of the virus. Here we will review well-characterized ts mutations for RNA viruses, and further discuss the potential in designing novel live-attenuated vaccines for RVF.

An Epidemiological Model of Rift Valley Fever with Spatial Dynamics

Directory of Open Access Journals (Sweden)

Tianchan Niu

2012-01-01

Full Text Available As a category A agent in the Center for Disease Control bioterrorism list, Rift Valley fever (RVF is considered a major threat to the United States (USA. Should the pathogen be intentionally or unintentionally introduced to the continental USA, there is tremendous potential for economic damages due to loss of livestock, trade restrictions, and subsequent food supply chain disruptions. We have incorporated the effects of space into a mathematical model of RVF in order to study the dynamics of the pathogen spread as affected by the movement of humans, livestock, and mosquitoes. The model accounts for the horizontal transmission of Rift Valley fever virus (RVFV between two mosquito and one livestock species, and mother-to-offspring transmission of virus in one of the mosquito species. Space effects are introduced by dividing geographic space into smaller patches and considering the patch-to-patch movement of species. For each patch, a system of ordinary differential equations models fractions of populations susceptible to, incubating, infectious with, or immune to RVFV. The main contribution of this work is a methodology for analyzing the likelihood of pathogen establishment should an introduction occur into an area devoid of RVF. Examples are provided for general and specific cases to illustrate the methodology.

The browse value of the Eastern Cape valley bushveld. | A.J. ...

African Journals Online (AJOL)

The feeding value of the Eastern Cape Valley Bushveld in terms of crude protein, digestible dry matter, digestible energy and metabolic energy, as selected by oesophageal fistulated Boer- and Angora goats was determined. Results show that the Valley Bushveld maintains a high feed value throughout the year. The high ...

Single-particle cryo-electron microscopy of Rift Valley fever virus

International Nuclear Information System (INIS)

Sherman, Michael B.; Freiberg, Alexander N.; Holbrook, Michael R.; Watowich, Stanley J.

2009-01-01

Rift Valley fever virus (RVFV; Bunyaviridae; Phlebovirus) is an emerging human and veterinary pathogen causing acute hepatitis in ruminants and has the potential to cause hemorrhagic fever in humans. We report a three-dimensional reconstruction of RVFV vaccine strain MP-12 (RVFV MP-12) by cryo-electron microcopy using icosahedral symmetry of individual virions. Although the genomic core of RVFV MP-12 is apparently poorly ordered, the glycoproteins on the virus surface are highly symmetric and arranged on a T = 12 icosahedral lattice. Our RVFV MP-12 structure allowed clear identification of inter-capsomer contacts and definition of possible glycoprotein arrangements within capsomers. This structure provides a detailed model for phleboviruses, opens new avenues for high-resolution structural studies of the bunyavirus family, and aids the design of antiviral diagnostics and effective subunit vaccines.

Single-particle cryo-electron microscopy of Rift Valley fever virus.

Science.gov (United States)

Sherman, Michael B; Freiberg, Alexander N; Holbrook, Michael R; Watowich, Stanley J

2009-04-25

Rift Valley fever virus (RVFV; Bunyaviridae; Phlebovirus) is an emerging human and veterinary pathogen causing acute hepatitis in ruminants and has the potential to cause hemorrhagic fever in humans. We report a three-dimensional reconstruction of RVFV vaccine strain MP-12 (RVFV MP-12) by cryo-electron microcopy using icosahedral symmetry of individual virions. Although the genomic core of RVFV MP-12 is apparently poorly ordered, the glycoproteins on the virus surface are highly symmetric and arranged on a T=12 icosahedral lattice. Our RVFV MP-12 structure allowed clear identification of inter-capsomer contacts and definition of possible glycoprotein arrangements within capsomers. This structure provides a detailed model for phleboviruses, opens new avenues for high-resolution structural studies of the bunyavirus family, and aids the design of antiviral diagnostics and effective subunit vaccines.

Mosquito host choices on livestock amplifiers of Rift Valley fever virus in Kenya

Science.gov (United States)

Animal hosts may vary in their attraction and acceptability as components of the host location process for assessing biting rates of vectors and risk of exposure to pathogens. However, these parameters remain poorly understood for mosquito vectors of the Rift Valley fever (RVF), an arboviral disease...

Acid-activated structural reorganization of the Rift Valley fever virus Gc fusion protein

NARCIS (Netherlands)

Boer, de S.M.; Kortekaas, J.A.; Spel, L.; Rottier, P.J.M.; Moormann, R.J.M.; Bosch, B.J.

2012-01-01

Entry of the enveloped Rift Valley fever virus (RVFV) into its host cell is mediated by the viral glycoproteins Gn and Gc. We investigated the RVFV entry process and its pH-dependent activation mechanism in particular using our recently developed nonspreading RVFV particle system. Entry of the virus

Surveillance of Rift Valley Fever in Iran between 2001 and 2011

Directory of Open Access Journals (Sweden)

Sadegh CHINIKAR

2013-06-01

Full Text Available Rift Valley fever virus (RVFV is an acute zoonotic viral disease that mostly affects ruminants with an occasional spillover as human infection. Following the outbreak of RVF in Saudi Arabia in 2000, surveillance of both animal and human population in Iran increased until 2011. During this period 1206 ovine, 405 caprine, 325 bovine and 28 camel samples were tested for RVFV in nine provinces in Iran. None of these samples tested IgG positive. Moreover, amongst 37 clinically suspected human cases of patients with RVF symptoms, none of these samples tested positive for RVFV. Despite the fact that no positive cases in human or animal populations were identified in Iran, surveillance and monitoring of viral haemorrhagic fevers including RVFV will continue.

Surveillance of Rift Valley Fever in Iran between 2001 and 2011

Directory of Open Access Journals (Sweden)

Sadegh CHINIKAR

2013-04-01

Full Text Available Rift Valley fever virus (RVFV is an acute zoonotic viral disease that mostly affects ruminants with an occasional spillover as human infection. Following the outbreak of RVF in Saudi Arabia in 2000, surveillance of both animal and human population in Iran increased until 2011. During this period 1206 ovine, 405 caprine, 325 bovine and 28 camel samples were tested for RVFV in nine provinces in Iran. None of these samples tested IgG positive. Moreover, amongst 37 clinically suspected human cases of patients with RVF symptoms, none of these samples tested positive for RVFV. Despite the fact that no positive cases in human or animal populations were identified in Iran, surveillance and monitoring of viral haemorrhagic fevers including RVFV will continue.

A Systematic Scoping Study of the Socio-Economic Impact of Rift Valley Fever

NARCIS (Netherlands)

Peyre, M.; Chevalier, V.; Abdo-Salem, S.; Velthuis, A.; Antoine-Moussiaux, N.; Thiry, E.; Roger, F.

2015-01-01

Rift Valley fever (RVF) is a severe mosquito-borne disease affecting humans and domestic ruminants. RVF virus has been reported in most African countries, as well as in the Arabic Peninsula. This paper reviews the different types of socio-economic impact induced by RVF disease and the attempts to

Transmission of Rift Valley fever virus from European-breed lambs to Culex pipiens mosquitoes

NARCIS (Netherlands)

Vloet, Rianka P.M.; Vogels, Chantal B.F.; Koenraadt, Constantianus J.M.; Pijlman, Gorben P.; Eiden, Martin; Gonzales, Jose L.; Keulen, van Lucien J.M.; Wichgers Schreur, Paul J.; Kortekaas, Jeroen

2017-01-01

Background: Rift Valley fever virus (RVFV) is a mosquito-borne bunyavirus of the genus Phlebovirus that is highly pathogenic to ruminants and humans. The disease is currently confined to Africa and the Arabian Peninsula, but globalization and climate change may facilitate introductions of the virus

The persistence of rift valley fever in the Jazan region of Saudi Arabia.

Science.gov (United States)

Elfadil, A A; Hasab-Allah, K A; Dafa-Allah, O M; Elmanea, A A

2006-12-01

A survey was conducted in the Jazan region of Saudi Arabia to investigate the presence of Rift Valley fever (RVF) in sheep and goats, by clinical identification of suspected herds and detection of immunoglobulin M (IgM) antibodies to RVF virus. The level of herd immunity was identified by detecting immunoglobulin G (IgG) antibodies. Rift Valley fever was diagnosed in six out of eight districts included in the survey. Twenty-two animals from 17 herds tested positive for the presence of IgM antibodies against RVF in these districts. The infection rate ranged from 0.12% in the Sabya district to 1.04% in the Jizan district. The level of herd immunity ranged from 22.2% in Jizan to 39.3% in the Alarda district. It can be concluded that the presence of IgM antibodies in clinically suspected herds suggests persistent RVF infection in the Jazan region. Thus, RVF control programmes should be continued to prevent the recurrence of outbreaks in the region and the possible further spread of infection to other regions of Saudi Arabia.

Effect of environmental temperature on the vector competence of mosquitoes for Rift Valley fever virus

Science.gov (United States)

Environmental temperature has been shown to affect the ability of mosquitoes to transmit numerous arboviruses and for Rift Valley fever virus (RVFV) in particular. We evaluated the effect of incubation temperatures ranging from 14-26ºC on infection, dissemination, and transmission rates for Culex ta...

Restriction of Rift Valley Fever Virus Virulence in Mosquito Cells

Directory of Open Access Journals (Sweden)

Sonja R. Gerrard

2010-02-01

Full Text Available Arboviruses are maintained in a natural cycle that requires blood-sucking arthropod and vertebrate hosts. Arboviruses are believed to persistently infect their arthropod host without overt pathology and cause acute infection with viremia in their vertebrate host. We have focused on elucidating how a specific arbovirus, Rift Valley fever (RVF virus, causes cytopathic effect in cells derived from vertebrates and non-cytopathic infection in cells derived from arthropods. We demonstrate that the vertebrate virulence factor, NSs, is functional in arthropod cells but is expressed at significantly lower levels in infected arthropod versus infected vertebrate cells.

Four-segmented Rift Valley fever virus-based vaccines can be applied safely in ewes during pregnancy

NARCIS (Netherlands)

Wichgers Schreur, Paul J.; Keulen, van Lucien; Kant-Eenbergen, Jet; Kortekaas, Jeroen

2017-01-01

Rift Valley fever virus (RVFV) causes severe and recurrent outbreaks on the African continent and the Arabian Peninsula and continues to expand its habitat. This mosquito-borne virus, belonging to the genus Phlebovirus of the family Bunyaviridae contains a tri-segmented negative-strand RNA

Rift Valley fever virus MP-12 vaccine encoding Toscana virus NSs retains neuroinvasiveness in mice.

Science.gov (United States)

Indran, Sabarish V; Lihoradova, Olga A; Phoenix, Inaia; Lokugamage, Nandadeva; Kalveram, Birte; Head, Jennifer A; Tigabu, Bersabeh; Smith, Jennifer K; Zhang, Lihong; Juelich, Terry L; Gong, Bin; Freiberg, Alexander N; Ikegami, Tetsuro

2013-07-01

Rift Valley fever is a mosquito-borne zoonotic disease endemic to sub-Saharan Africa. Rift Valley fever virus (RVFV; genus Phlebovirus, family Bunyaviridae) causes high rates of abortion and fetal malformation in pregnant ruminants, and haemorrhagic fever, neurological disorders or blindness in humans. The MP-12 strain is a highly efficacious and safe live-attenuated vaccine candidate for both humans and ruminants. However, MP-12 lacks a marker to differentiate infected from vaccinated animals. In this study, we originally aimed to characterize the efficacy of a recombinant RVFV MP-12 strain encoding Toscana virus (TOSV) NSs gene in place of MP-12 NSs (rMP12-TOSNSs). TOSV NSs promotes the degradation of dsRNA-dependent protein kinase (PKR) and inhibits interferon-β gene up-regulation without suppressing host general transcription. Unexpectedly, rMP12-TOSNSs increased death in vaccinated outbred mice and inbred BALB/c or C57BL/6 mice. Immunohistochemistry showed diffusely positive viral antigens in the thalamus, hypothalamus and brainstem, including the medulla. No viral antigens were detected in spleen or liver, which is similar to the antigen distribution of moribund mice infected with MP-12. These results suggest that rMP12-TOSNSs retains neuroinvasiveness in mice. Our findings demonstrate that rMP12-TOSNSs causes neuroinvasion without any hepatic disease and will be useful for studying the neuroinvasion mechanism of RVFV and TOSV.

Potential for Mosquitoes (Diptera: Culicidae) From Florida to Transmit Rift Valley Fever Virus

Science.gov (United States)

2013-09-01

signiÞcant disease and economic disruption. Rift Valley fever virus (RVFV), whichhasbeen responsible fornumerousoutbreaksof severe disease in ruminants and...is predominately a disease of domestic ruminants (cattle, goats, and sheep), where infection in pregnant animals usually results in abortion, and...www.cdc.gov/EID/ content /13/8/e1.htm). Britch, S.C.,K. J.Linthicum,A.Anyamba,C. J.Tucker,E.W. Pak, F. A. Maloney, K. Cobb, E. Stanwix, J. Humphries, A

Arabidopsis thaliana plants expressing Rift Valley fever virus antigens: Mice exhibit systemic immune responses as the result of oral administration of the transgenic plants.

Science.gov (United States)

Kalbina, Irina; Lagerqvist, Nina; Moiane, Bélisario; Ahlm, Clas; Andersson, Sören; Strid, Åke; Falk, Kerstin I

2016-11-01

The zoonotic Rift Valley fever virus affects livestock and humans in Africa and on the Arabian Peninsula. The economic impact of this pathogen due to livestock losses, as well as its relevance to public health, underscores the importance of developing effective and easily distributed vaccines. Vaccines that can be delivered orally are of particular interest. Here, we report the expression in transformed plants (Arabidopsis thaliana) of Rift Valley fever virus antigens. The antigens used in this study were the N protein and a deletion mutant of the Gn glycoprotein. Transformed lines were analysed for specific mRNA and protein content by RT-PCR and Western blotting, respectively. Furthermore, the plant-expressed antigens were evaluated for their immunogenicity in mice fed the transgenic plants. After oral intake of fresh transgenic plant material, a proportion of the mice elicited specific IgG antibody responses, as compared to the control animals that were fed wild-type plants and of which none sero-converted. Thus, we show that transgenic plants can be readily used to express and produce Rift Valley Fever virus proteins, and that the plants are immunogenic when given orally to mice. These are promising findings and provide a basis for further studies on edible plant vaccines against the Rift Valley fever virus. Copyright © 2016 Elsevier Inc. All rights reserved.

Countermeasure development for Rift Valley fever: deletion, modification or targeting of major virulence factor NSs.

Science.gov (United States)

Lihoradova, Olga; Ikegami, Tetsuro

2014-01-01

Rift Valley fever (RVF) is a mosquito-borne zoonotic disease characterized by a high rate of abortion in ruminants, and febrile illness, hemorrhagic fever, retinitis and encephalitis in humans. RVF is caused by the RVF virus (RVFV), belonging to the genus Phlebovirus of the family Bunyaviridae . RVFV encodes a major virulence factor, NSs , which is dispensable for viral replication, yet required for evasion of host innate immune responses. RVFV NSs inhibits host gene upregulation at the transcriptional level, while promoting viral translation in the cytoplasm. In this article, we summarize the virology and pathology of RVF, and countermeasure development for RVF, with emphasis on NSs function and applications.

Detection of Rift Valley Fever Virus Interepidemic Activity in Some Hotspot Areas of Kenya by Sentinel Animal Surveillance, 2009–2012

Directory of Open Access Journals (Sweden)

Jacqueline Kasiiti Lichoti

2014-01-01

Full Text Available Rift Valley fever virus causes an important zoonotic disease of humans and small ruminants in Eastern Africa and is spread primarily by a mosquito vector. In this region, it occurs as epizootics that typically occur at 5–15-year intervals associated with unusual rainfall events. It has hitherto been known that the virus is maintained between outbreaks in dormant eggs of the mosquito vector and this has formed the basis of understanding of the epidemiology and control strategies of the disease. We show here that seroconversion and sporadic acute disease do occur during the interepidemic periods (IEPs in the absence of reported cases in livestock or humans. The finding indicates that previously undetected low-level virus transmission during the IEPs does occur and that epizootics may also be due to periodic expansion of mosquito vectors in the presence of both circulating virus and naïve animals.

Attenuation of pathogenic Rift Valley fever virus strain through the chimeric S-segment encoding sandfly fever phlebovirus NSs or a dominant-negative PKR.

Science.gov (United States)

Nishiyama, Shoko; Slack, Olga A L; Lokugamage, Nandadeva; Hill, Terence E; Juelich, Terry L; Zhang, Lihong; Smith, Jennifer K; Perez, David; Gong, Bin; Freiberg, Alexander N; Ikegami, Tetsuro

2016-11-16

Rift Valley fever is a mosquito-borne zoonotic disease affecting ruminants and humans. Rift Valley fever virus (RVFV: family Bunyaviridae, genus Phlebovirus) causes abortions and fetal malformations in ruminants, and hemorrhagic fever, encephalitis, or retinitis in humans. The live-attenuated MP-12 vaccine is conditionally licensed for veterinary use in the US. However, this vaccine lacks a marker for the differentiation of vaccinated from infected animals (DIVA). NSs gene is dispensable for RVFV replication, and thus, rMP-12 strains lacking NSs gene is applicable to monitor vaccinated animals. However, the immunogenicity of MP-12 lacking NSs was not as high as parental MP-12. Thus, chimeric MP-12 strains encoding NSs from either Toscana virus (TOSV), sandfly fever Sicilian virus (SFSV) or Punta Toro virus Adames strain (PTA) were characterized previously. Although chimeric MP-12 strains are highly immunogenic, the attenuation through the S-segment remains unknown. Using pathogenic ZH501 strain, we aimed to demonstrate the attenuation of ZH501 strain through chimeric S-segment encoding either the NSs of TOSV, SFSV, PTA, or Punta Toro virus Balliet strain (PTB). In addition, we characterized rZH501 encoding a human dominant-negative PKR (PKRΔE7), which also enhances the immunogenicity of MP-12. Study done on mice revealed that attenuation of rZH501 occurred through the S-segment encoding either PKRΔE7 or SFSV NSs. However, rZH501 encoding either TOSV, PTA, or PTB NSs in the S-segment uniformly caused lethal encephalitis. Our results indicated that the S-segments encoding PKRΔE7 or SFSV NSs are attenuated and thus applicable toward next generation MP-12 vaccine candidates that encode a DIVA marker.

Ecological niche modelling of Rift Valley fever virus vectors in Baringo, Kenya

Directory of Open Access Journals (Sweden)

Alfred O. Ochieng

2016-11-01

Full Text Available Background: Rift Valley fever (RVF is a vector-borne zoonotic disease that has an impact on human health and animal productivity. Here, we explore the use of vector presence modelling to predict the distribution of RVF vector species under climate change scenario to demonstrate the potential for geographic spread of Rift Valley fever virus (RVFV. Objectives: To evaluate the effect of climate change on RVF vector distribution in Baringo County, Kenya, with an aim of developing a risk map for spatial prediction of RVF outbreaks. Methodology: The study used data on vector presence and ecological niche modelling (MaxEnt algorithm to predict the effect of climatic change on habitat suitability and the spatial distribution of RVF vectors in Baringo County. Data on species occurrence were obtained from longitudinal sampling of adult mosquitoes and larvae in the study area. We used present (2000 and future (2050 Bioclim climate databases to model the vector distribution. Results: Model results predicted potential suitable areas with high success rates for Culex quinquefasciatus, Culex univitattus, Mansonia africana, and Mansonia uniformis. Under the present climatic conditions, the lowlands were found to be highly suitable for all the species. Future climatic conditions indicate an increase in the spatial distribution of Cx. quinquefasciatus and M. africana. Model performance was statistically significant. Conclusion: Soil types, precipitation in the driest quarter, precipitation seasonality, and isothermality showed the highest predictive potential for the four species.

The Rift Valley fever: could re-emerge in Egypt again?

Science.gov (United States)

El-Bahnasawy, Mamdouh; Megahed, Laila Abdel-Mawla; Abdalla Saleh, Hala Ahmed; Morsy, Tosson A

2013-04-01

The Rift Valley fever (RVF) is a neglected, emerging, mosquito-borne disease with severe negative impact on human and animal health and economy. RVF is caused by RVF virus of the family of Bunyaviridae, genus Phlebovirus. RVF is an acute, febrile disease affecting humans and a wide range of animals. The virus is trans-mitted through the bites from mosquitoes and exposure to viremic blood, body fluids, or contact with tissues of infected animals or by inhaling natural virus aerosols, also possibly by consumption of infected unpasteurized milk. The RVF-virus replicate at the site introduction and in local lymphatic followed by viremia and spread to other organs as the liver and central nervous system, causing the hepatic necrosis and eosinophilia cytoplasmic degeneration. The main signs and symptoms are fever, headache, myalgia, arthralgia, photophobia, bradycardia, conjunctivitis and flushing face. Main complications include jaundice, hemorrhagic, meningoencephalitis and retinal lesions. Generally speaking, in the 21st Century, the vector-borne infectious diseases, was accepted as the disaster issues with the considerable significant morbidity and mortality. These facts should be considered by the public health, veterinary and agricultural authorities

Identification of a major non-structural protein in the nuclei of Rift Valley fever virus-infected cells.

Science.gov (United States)

Struthers, J K; Swanepoel, R

1982-06-01

A non-structural protein of mol. wt. 34 X 10(3) was demonstrated in the nuclei of Rift Valley fever virus-infected Vero cells by SDS-polyacrylamide gel electro-phoresis. The protein appears to correspond to the virus-induced antigen demonstrated by indirect immunofluorescence in intranuclear inclusions.

Characterization of Rift Valley fever virus MP-12 strain encoding NSs of Punta Toro virus or sandfly fever Sicilian virus.

Science.gov (United States)

Lihoradova, Olga A; Indran, Sabarish V; Kalveram, Birte; Lokugamage, Nandadeva; Head, Jennifer A; Gong, Bin; Tigabu, Bersabeh; Juelich, Terry L; Freiberg, Alexander N; Ikegami, Tetsuro

2013-01-01

Rift Valley fever virus (RVFV; genus Phlebovirus, family Bunyaviridae) is a mosquito-borne zoonotic pathogen which can cause hemorrhagic fever, neurological disorders or blindness in humans, and a high rate of abortion in ruminants. MP-12 strain, a live-attenuated candidate vaccine, is attenuated in the M- and L-segments, but the S-segment retains the virulent phenotype. MP-12 was manufactured as an Investigational New Drug vaccine by using MRC-5 cells and encodes a functional NSs gene, the major virulence factor of RVFV which 1) induces a shutoff of the host transcription, 2) inhibits interferon (IFN)-β promoter activation, and 3) promotes the degradation of dsRNA-dependent protein kinase (PKR). MP-12 lacks a marker for differentiation of infected from vaccinated animals (DIVA). Although MP-12 lacking NSs works for DIVA, it does not replicate efficiently in type-I IFN-competent MRC-5 cells, while the use of type-I IFN-incompetent cells may negatively affect its genetic stability. To generate modified MP-12 vaccine candidates encoding a DIVA marker, while still replicating efficiently in MRC-5 cells, we generated recombinant MP-12 encoding Punta Toro virus Adames strain NSs (rMP12-PTNSs) or Sandfly fever Sicilian virus NSs (rMP12-SFSNSs) in place of MP-12 NSs. We have demonstrated that those recombinant MP-12 viruses inhibit IFN-β mRNA synthesis, yet do not promote the degradation of PKR. The rMP12-PTNSs, but not rMP12-SFSNSs, replicated more efficiently than recombinant MP-12 lacking NSs in MRC-5 cells. Mice vaccinated with rMP12-PTNSs or rMP12-SFSNSs induced neutralizing antibodies at a level equivalent to those vaccinated with MP-12, and were efficiently protected from wild-type RVFV challenge. The rMP12-PTNSs and rMP12-SFSNSs did not induce antibodies cross-reactive to anti-RVFV NSs antibody and are therefore applicable to DIVA. Thus, rMP12-PTNSs is highly efficacious, replicates efficiently in MRC-5 cells, and encodes a DIVA marker, all of which are

A Novel System for Identification of Inhibitors of Rift Valley Fever Virus Replication

OpenAIRE

Piper, Mary E.; Gerrard, Sonja R.

2010-01-01

Rift Valley fever virus (RVFV) is a human and livestock pathogen endemic to sub-Saharan Africa. We have developed a T7-dependent system for the efficient production of RVFV-like particles (RVF-VLPs) based on the virulent ZH-501 strain of RVFV. The RVF-VLPs are capable of performing a single round of infection, allowing for the study of viral replication, assembly, and infectivity. We demonstrate that these RVF-VLPs are antigenically indistinguishable from authentic RVFV and respond similarly ...

Rift Valley fever virus NSs protein functions and the similarity to other bunyavirus NSs proteins.

Science.gov (United States)

Ly, Hoai J; Ikegami, Tetsuro

2016-07-02

Rift Valley fever is a mosquito-borne zoonotic disease that affects both ruminants and humans. The nonstructural (NS) protein, which is a major virulence factor for Rift Valley fever virus (RVFV), is encoded on the S-segment. Through the cullin 1-Skp1-Fbox E3 ligase complex, the NSs protein promotes the degradation of at least two host proteins, the TFIIH p62 and the PKR proteins. NSs protein bridges the Fbox protein with subsequent substrates, and facilitates the transfer of ubiquitin. The SAP30-YY1 complex also bridges the NSs protein with chromatin DNA, affecting cohesion and segregation of chromatin DNA as well as the activation of interferon-β promoter. The presence of NSs filaments in the nucleus induces DNA damage responses and causes cell-cycle arrest, p53 activation, and apoptosis. Despite the fact that NSs proteins have poor amino acid similarity among bunyaviruses, the strategy utilized to hijack host cells are similar. This review will provide and summarize an update of recent findings pertaining to the biological functions of the NSs protein of RVFV as well as the differences from those of other bunyaviruses.

Mapping of the mutations present in the genome of the Rift Valley fever virus attenuated MP12 strain and their putative role in attenuation.

Science.gov (United States)

Vialat, P; Muller, R; Vu, T H; Prehaud, C; Bouloy, M

1997-11-01

The MP12 attenuated strain of Rift Valley fever virus was obtained by 12 serial passages of a virulent isolate ZH548 in the presence of 5-fluorouracil (Caplen et al., 1985. Mutagen-directed attenuation of Rift Valley fever virus as a method for vaccine development. J. Gen. Virol., 66, 2271-2277). The comparison of the M segment of the two strains has already been reported by Takehara et al. (Takehara et al., 1989. Identification of mutations in the M RNA of a candidate vaccine strain of Rift Valley fever virus. Virology 169, 452-457). We have completed the comparison and found that altogether a total of nine, 12 and four nucleotides were changed in the L, M and S segments of the two strains, respectively. Three mutations induced amino acid changes in the L protein but none of them was located in the recognized motifs conserved among RNA dependent polymerases. In the S segment, a single change modified an amino acid in the NSs protein and in the M segment, seven of the mutations resulted in amino acid changes in each of the four encoded G1, G2, 14 kDa and 78 kDa proteins. Characterization of the MP12 virus indicated that determinants for attenuation were present in each segment and that they were introduced progressively during the 12 passages in the presence of the mutagen (Saluzzo and Smith, 1990. Use of reassortant viruses to map attenuating and temperature-sensitive mutations of the Rift Valley fever virus MP-12 vaccine. Vaccine 8, 369-375). Passages 4 and 7-9 were found to be essential for introduction of temperature-sensitive lesions and attenuation. In an attempt to correlate some of the mutations with the attenuated or temperature-sensitive phenotypes, we determined by sequencing the passage level at which the different mutations appeared. This work should help to address the question of the role of the viral gene products in Rift Valley fever pathogenesis.

Immunogenicity and efficacy of a chimpanzee adenovirus-vectored Rift Valley fever vaccine in mice.

OpenAIRE

Warimwe, GM; Lorenzo, G; Lopez-Gil, E; Reyes-Sandoval, A; Cottingham, MG; Spencer, AJ; Collins, KA; Dicks, MD; Milicic, A; Lall, A; Furze, J; Turner, AV; Hill, AV; Brun, A; Gilbert, SC

2013-01-01

BACKGROUND: Rift Valley Fever (RVF) is a viral zoonosis that historically affects livestock production and human health in sub-Saharan Africa, though epizootics have also occurred in the Arabian Peninsula. Whilst an effective live-attenuated vaccine is available for livestock, there is currently no licensed human RVF vaccine. Replication-deficient chimpanzee adenovirus (ChAd) vectors are an ideal platform for development of a human RVF vaccine, given the low prevalence of neutralizing antibod...

Geothermal systems of the Mono Basin-Long Valley region, eastern California and western Nevada

Energy Technology Data Exchange (ETDEWEB)

Higgins, C.T.; Flynn, T.; Chapman, R.H.; Trexler, D.T.; Chase, G.R.; Bacon, C.F.; Ghusn, G. Jr.

1985-01-01

The region that includes Mono Basin, Long Valley, the Bridgeport-Bodie Hills area, and Aurora, in eastern California and western Nevada was studied to determine the possible causes and interactions of the geothermal anomalies in the Mono Basin-Long Valley region as a whole. A special goal of the study was to locate possible shallow bodies of magma and to determine their influence on the hydrothermal systems in the region. (ACR)

[Rift Valley fever: sporadic infection of French military personnel outside currently recognized epidemic zones].

Science.gov (United States)

Durand, J P; Richecoeur, L; Peyrefitte, C; Boutin, J P; Davoust, B; Zeller, H; Bouloy, M; Tolou, H

2002-01-01

For three years the arbovirus surveillance unit of the Tropical Medicine Institute of the French Army Medical Corps (French acronym IMTSSA) in Marseille, France has been investigating causes of benign non-malarial febrile syndromes in French military personnel serving outside mainland France. The methodology used in N'Djamena consisted of sending frozen specimens collected concomitant with viremia, to Marseille for culture. During the rainy season of 2001, specimens were collected from a total of 50 febrile soldiers. Cultures allowed isolation and identification of two strains of Rift Valley virus. The risk of contamination exists not only in the field but also in mainland hospital departments treating infected patients. Routine serological diagnosis for Rift Valley fever must be DISCUSSED for all patients in the field or returning from Africa.

Interim Report on SNP analysis and forensic microarray probe design for South American hemorrhagic fever viruses, tick-borne encephalitis virus, henipaviruses, Old World Arenaviruses, filoviruses, Crimean-Congo hemorrhagic fever viruses, Rift Valley fever

Energy Technology Data Exchange (ETDEWEB)

Jaing, C; Gardner, S

2012-06-05

The goal of this project is to develop forensic genotyping assays for select agent viruses, enhancing the current capabilities for the viral bioforensics and law enforcement community. We used a multipronged approach combining bioinformatics analysis, PCR-enriched samples, microarrays and TaqMan assays to develop high resolution and cost effective genotyping methods for strain level forensic discrimination of viruses. We have leveraged substantial experience and efficiency gained through year 1 on software development, SNP discovery, TaqMan signature design and phylogenetic signature mapping to scale up the development of forensics signatures in year 2. In this report, we have summarized the whole genome wide SNP analysis and microarray probe design for forensics characterization of South American hemorrhagic fever viruses, tick-borne encephalitis viruses and henipaviruses, Old World Arenaviruses, filoviruses, Crimean-Congo hemorrhagic fever virus, Rift Valley fever virus and Japanese encephalitis virus.

Q fever in Greenland

DEFF Research Database (Denmark)

Koch, Anders; Svendsen, Claus Bo; Christensen, Jens Jorgen

2010-01-01

We report a patient with Q fever endocarditis in a settlement in eastern Greenland (Isortoq, Ammassalik area). Likely animal sources include sled dogs and seals. Q fever may be underdiagnosed in Arctic areas but may also represent an emerging infection.......We report a patient with Q fever endocarditis in a settlement in eastern Greenland (Isortoq, Ammassalik area). Likely animal sources include sled dogs and seals. Q fever may be underdiagnosed in Arctic areas but may also represent an emerging infection....

Rift Valley fever virus NS{sub S} gene expression correlates with a defect in nuclear mRNA export

Energy Technology Data Exchange (ETDEWEB)

Copeland, Anna Maria; Van Deusen, Nicole M.; Schmaljohn, Connie S., E-mail: Connie.s.schmaljohn.civ@mail.mil

2015-12-15

We investigated the localization of host mRNA during Rift Valley fever virus (RVFV) infection. Fluorescence in situ hybridization revealed that infection with RVFV altered the localization of host mRNA. mRNA accumulated in the nuclei of RVFV-infected but not mock-infected cells. Further, overexpression of the NS{sub S} gene, but not the N, G{sub N} or NS{sub M} genes correlated with mRNA nuclear accumulation. Nuclear accumulation of host mRNA was not observed in cells infected with a strain of RVFV lacking the gene encoding NS{sub S}, confirming that expression of NS{sub S} is likely responsible for this phenomenon. - Highlights: • Rift Valley fever virus (RVFV) infection alters the localization of host mRNA. • mRNA accumulates in the nuclei of RVFV-infected but not mock-infected cells. • NS{sub S} is likely responsible for mRNA relocalization to the nucleus.

NSs protein of severe fever with thrombocytopenia syndrome virus suppresses interferon production through different mechanism than Rift Valley fever virus.

Science.gov (United States)

Zhang, S; Zheng, B; Wang, T; Li, A; Wan, J; Qu, J; Li, C H; Li, D; Liang, M

Severe fever with thrombocytopenia syndrome virus (SFTSV) is a newly identified Phlebovirus that causes severe fever with thrombocytopenia syndrome. Our study demonstrated that SFTSV NSs functioned as IFN antagonist mainly by suppressing TBK1/IKKε-IRF3 signaling pathway. NSs interacted with and relocalized TANK-binding kinase 1 (TBK1) into NSs-induced cytoplasmic structures and this interaction could effectively inhibit downstream phosphorylation and dimerization of interferon regulatory factor 3 (IRF3), resulting in the suppression of antiviral signaling and IFN induction. Functional sites of SFTSV NSs binding with TBK1 were then studied and results showed that NSs had lost their IFN-inhibiting activity after deleting the 25 amino acids in N-terminal. Furthermore, the mechanism of Rift Valley fever virus (RVFV) NSs blocking IFN-β response were also investigated. Preliminary results showed that RVFV NSs proteins could neither interact nor co-localize with TBK1 in cytoplasm, but suppressed its expression levels, phosphorylation and dimerization of IRF3 in the subsequent steps, resulting in inhibition of the IFN-β production. Altogether, our data demonstrated the probable mechanism used by SFTSV to inhibit IFN responses which was different from RVFV and pointed toward a novel mechanism for RVFV suppressing IFN responses.

Remote Sensing Contributions to Prediction and Risk Assessment of Natural Disasters Caused by Large Scale Rift Valley Fever Outbreaks

Science.gov (United States)

Anyamba, Assaf; Linthicum, Kenneth J.; Small, Jennifer; Britch, S. C.; Tucker, C. J.

2012-01-01

Remotely sensed vegetation measurements for the last 30 years combined with other climate data sets such as rainfall and sea surface temperatures have come to play an important role in the study of the ecology of arthropod-borne diseases. We show that epidemics and epizootics of previously unpredictable Rift Valley fever are directly influenced by large scale flooding associated with the El Ni o/Southern Oscillation. This flooding affects the ecology of disease transmitting arthropod vectors through vegetation development and other bioclimatic factors. This information is now utilized to monitor, model, and map areas of potential Rift Valley fever outbreaks and is used as an early warning system for risk reduction of outbreaks to human and animal health, trade, and associated economic impacts. The continuation of such satellite measurements is critical to anticipating, preventing, and managing disease epidemics and epizootics and other climate-related disasters.

Innate Immune Response to Rift Valley Fever Virus in Goats

Science.gov (United States)

Nfon, Charles K.; Marszal, Peter; Zhang, Shunzhen; Weingartl, Hana M.

2012-01-01

Rift Valley fever (RVF), a re-emerging mosquito-borne disease of ruminants and man, was endemic in Africa but spread to Saudi Arabia and Yemen, meaning it could spread even further. Little is known about innate and cell-mediated immunity to RVF virus (RVFV) in ruminants, which is knowledge required for adequate vaccine trials. We therefore studied these aspects in experimentally infected goats. We also compared RVFV grown in an insect cell-line and that grown in a mammalian cell-line for differences in the course of infection. Goats developed viremia one day post infection (DPI), which lasted three to four days and some goats had transient fever coinciding with peak viremia. Up to 4% of peripheral blood mononuclear cells (PBMCs) were positive for RVFV. Monocytes and dendritic cells in PBMCs declined possibly from being directly infected with virus as suggested by in vitro exposure. Infected goats produced serum IFN-γ, IL-12 and other proinflammatory cytokines but not IFN-α. Despite the lack of IFN-α, innate immunity via the IL-12 to IFN-γ circuit possibly contributed to early protection against RVFV since neutralising antibodies were detected after viremia had cleared. The course of infection with insect cell-derived RVFV (IN-RVFV) appeared to be different from mammalian cell-derived RVFV (MAM-RVFV), with the former attaining peak viremia faster, inducing fever and profoundly affecting specific immune cell subpopulations. This indicated possible differences in infections of ruminants acquired from mosquito bites relative to those due to contact with infectious material from other animals. These differences need to be considered when testing RVF vaccines in laboratory settings. PMID:22545170

Preliminary report on the geology of the Red River Valley drilling project, eastern North Dakota and northwestern Minnesota

International Nuclear Information System (INIS)

Moore, W.L.

1979-01-01

Thirty-two wells, 26 of which penetrated the Precambrian, were drilled along the eastern edge of the Williston Basin in the eastern tier of counties in North Dakota and in nearby counties in northwestern Minnesota. These tests, along the Red River Valley of the North, were drilled to study the stratigraphy and uranium potential of this area. The drilling program was unsuccessful in finding either significant amounts of uranium or apparently important shows of uranium. It did, however, demonstrate the occurrence of thick elastic sections in the Ordovician, Jurassic and Cretaceous Systems, within the Red River Valley, along the eastern margins of the Williston Basin which could serve as host rocks for uranium ore bodies

Efficient cellular release of Rift Valley fever virus requires genomic RNA.

Directory of Open Access Journals (Sweden)

Mary E Piper

2011-03-01

Full Text Available The Rift Valley fever virus is responsible for periodic, explosive epizootics throughout sub-Saharan Africa. The development of therapeutics targeting this virus is difficult due to a limited understanding of the viral replicative cycle. Utilizing a virus-like particle system, we have established roles for each of the viral structural components in assembly, release, and virus infectivity. The envelope glycoprotein, Gn, was discovered to be necessary and sufficient for packaging of the genome, nucleocapsid protein and the RNA-dependent RNA polymerase into virus particles. Additionally, packaging of the genome was found to be necessary for the efficient release of particles, revealing a novel mechanism for the efficient generation of infectious virus. Our results identify possible conserved targets for development of anti-phlebovirus therapies.

Rift Valley Fever Outbreaks in Mauritania and Related Environmental Conditions

Directory of Open Access Journals (Sweden)

Cyril Caminade

2014-01-01

Full Text Available Four large outbreaks of Rift Valley Fever (RVF occurred in Mauritania in 1998, 2003, 2010 and 2012 which caused lots of animal and several human deaths. We investigated rainfall and vegetation conditions that might have impacted on RVF transmission over the affected regions. Our results corroborate that RVF transmission generally occurs during the months of September and October in Mauritania, similarly to Senegal. The four outbreaks were preceded by a rainless period lasting at least a week followed by heavy precipitation that took place during the second half of the rainy season. First human infections were generally reported three to five weeks later. By bridging the gap between meteorological forecasting centers and veterinary services, an early warning system might be developed in Senegal and Mauritania to warn decision makers and health services about the upcoming RVF risk.

Rift Valley fever virus infection in golden Syrian hamsters.

Directory of Open Access Journals (Sweden)

Dionna Scharton

Full Text Available Rift Valley fever virus (RVFV is a formidable pathogen that causes severe disease and abortion in a variety of livestock species and a range of disease in humans that includes hemorrhagic fever, fulminant hepatitis, encephalitis and blindness. The natural transmission cycle involves mosquito vectors, but exposure can also occur through contact with infected fluids and tissues. The lack of approved antiviral therapies and vaccines for human use underlies the importance of small animal models for proof-of-concept efficacy studies. Several mouse and rat models of RVFV infection have been well characterized and provide useful systems for the study of certain aspects of pathogenesis, as well as antiviral drug and vaccine development. However, certain host-directed therapeutics may not act on mouse or rat pathways. Here, we describe the natural history of disease in golden Syrian hamsters challenged subcutaneously with the pathogenic ZH501 strain of RVFV. Peracute disease resulted in rapid lethality within 2 to 3 days of RVFV challenge. High titer viremia and substantial viral loads were observed in most tissues examined; however, histopathology and immunostaining for RVFV antigen were largely restricted to the liver. Acute hepatocellular necrosis associated with a strong presence of viral antigen in the hepatocytes indicates that fulminant hepatitis is the likely cause of mortality. Further studies to assess the susceptibility and disease progression following respiratory route exposure are warranted. The use of the hamsters to model RVFV infection is suitable for early stage antiviral drug and vaccine development studies.

Audiomagnetotelluric investigation of Snake Valley, eastern Nevada and western Utah

Science.gov (United States)

McPhee, Darcy K.; Pari, Keith; Baird, Frank

2009-01-01

Audiomagnetotelluric (AMT) data along four profiles in western Snake Valley and the corresponding two-dimensional (2-D) inverse models reveal subsurface structures that may be significant to ground-water investigations in the area. The AMT method is a valuable tool for estimating the electrical resistivity of the earth over depth ranges from a few meters to less than one kilometer. The method has the potential to identify faults and stratigraphy within basins of eastern Nevada, thereby helping define the hydrogeologic framework of the region.

A Novel System for Identification of Inhibitors of Rift Valley Fever Virus Replication

Directory of Open Access Journals (Sweden)

Mary E. Piper

2010-03-01

Full Text Available Rift Valley fever virus (RVFV is a human and livestock pathogen endemic to sub-Saharan Africa. We have developed a T7-dependent system for the efficient production of RVFV-like particles (RVF-VLPs based on the virulent ZH-501 strain of RVFV. The RVF-VLPs are capable of performing a single round of infection, allowing for the study of viral replication, assembly, and infectivity. We demonstrate that these RVF-VLPs are antigenically indistinguishable from authentic RVFV and respond similarly to a wide array of known and previously unknown chemical inhibitors. This system should be useful for screening for small molecule inhibitors of RVFV replication.

A novel system for identification of inhibitors of rift valley Fever virus replication.

Science.gov (United States)

Piper, Mary E; Gerrard, Sonja R

2010-03-01

Rift Valley fever virus (RVFV) is a human and livestock pathogen endemic to sub-Saharan Africa. We have developed a T7-dependent system for the efficient production of RVFV-like particles (RVF-VLPs) based on the virulent ZH-501 strain of RVFV. The RVF-VLPs are capable of performing a single round of infection, allowing for the study of viral replication, assembly, and infectivity. We demonstrate that these RVF-VLPs are antigenically indistinguishable from authentic RVFV and respond similarly to a wide array of known and previously unknown chemical inhibitors. This system should be useful for screening for small molecule inhibitors of RVFV replication.

Flinders Island spotted fever rickettsioses caused by "marmionii" strain of Rickettsia honei, Eastern Australia.

Science.gov (United States)

Unsworth, Nathan B; Stenos, John; Graves, Stephen R; Faa, Antony G; Cox, G Erika; Dyer, John R; Boutlis, Craig S; Lane, Amanda M; Shaw, Matthew D; Robson, Jennifer; Nissen, Michael D

2007-04-01

Australia has 4 rickettsial diseases: murine typhus, Queensland tick typhus, Flinders Island spotted fever, and scrub typhus. We describe 7 cases of a rickettsiosis with an acute onset and symptoms of fever (100%), headache (71%), arthralgia (43%), myalgia (43%), cough (43%), maculopapular/petechial rash (43%), nausea (29%), pharyngitis (29%), lymphadenopathy (29%), and eschar (29%). Cases were most prevalent in autumn and from eastern Australia, including Queensland, Tasmania, and South Australia. One patient had a history of tick bite (Haemaphysalis novaeguineae). An isolate shared 99.2%, 99.8%, 99.8%, 99.9%, and 100% homology with the 17 kDa, ompA, gltA, 16S rRNA, and Sca4 genes, respectively, of Rickettsia honei. This Australian rickettsiosis has similar symptoms to Flinders Island spotted fever, and the strain is genetically related to R. honei. It has been designated the "marmionii" strain of R. honei, in honor of Australian physician and scientist Barrie Marmion.

Risk analysis of inter-species reassortment through a Rift Valley fever phlebovirus MP-12 vaccine strain.

Directory of Open Access Journals (Sweden)

Hoai J Ly

Full Text Available Rift Valley fever (RVF is a mosquito-borne zoonotic disease endemic to Africa and the Arabian Peninsula. The causative agent, Rift Valley fever phlebovirus (RVFV, belongs to the genus Phlebovirus in the family Phenuiviridae and causes high rates of abortions in ruminants, and hemorrhagic fever, encephalitis, or blindness in humans. Viral maintenance by mosquito vectors has led to sporadic RVF outbreaks in ruminants and humans in endemic countries, and effective vaccination of animals and humans may minimize the impact of this disease. A live-attenuated MP-12 vaccine strain is one of the best characterized RVFV strains, and was conditionally approved as a veterinary vaccine in the U.S. Live-attenuated RVF vaccines including MP-12 strain may form reassortant strains with other bunyavirus species. This study thus aimed to characterize the occurrence of genetic reassortment between the MP-12 strain and bunyavirus species closely related to RVFV. The Arumowot virus (AMTV and Gouleako goukovirus (GOLV, are transmitted by mosquitoes in Africa. The results of this study showed that GOLV does not form detectable reassortant strains with the MP-12 strain in co-infected C6/36 cells. The AMTV also did not form any reassortant strains with MP-12 strain in co-infected C6/36 cells, due to the incompatibility among N, L, and Gn/Gc proteins. A lack of reassortant formation could be due to a functional incompatibility of N and L proteins derived from heterologous species, and due to a lack of packaging via heterologous Gn/Gc proteins. The MP-12 strain did, however, randomly exchange L-, M-, and S-segments with a genetic variant strain, rMP12-GM50, in culture cells. The MP-12 strain is thus unlikely to form any reassortant strains with AMTV or GOLV in nature.

Spatial Heterogeneity of Habitat Suitability for Rift Valley Fever Occurrence in Tanzania: An Ecological Niche Modelling Approach

Science.gov (United States)

Sindato, Calvin; Stevens, Kim B.; Karimuribo, Esron D.; Mboera, Leonard E. G.; Paweska, Janusz T.; Pfeiffer, Dirk U.

2016-01-01

Background Despite the long history of Rift Valley fever (RVF) in Tanzania, extent of its suitable habitat in the country remains unclear. In this study we investigated potential effects of temperature, precipitation, elevation, soil type, livestock density, rainfall pattern, proximity to wild animals, protected areas and forest on the habitat suitability for RVF occurrence in Tanzania. Materials and Methods Presence-only records of 193 RVF outbreak locations from 1930 to 2007 together with potential predictor variables were used to model and map the suitable habitats for RVF occurrence using ecological niche modelling. Ground-truthing of the model outputs was conducted by comparing the levels of RVF virus specific antibodies in cattle, sheep and goats sampled from locations in Tanzania that presented different predicted habitat suitability values. Principal Findings Habitat suitability values for RVF occurrence were higher in the northern and central-eastern regions of Tanzania than the rest of the regions in the country. Soil type and precipitation of the wettest quarter contributed equally to habitat suitability (32.4% each), followed by livestock density (25.9%) and rainfall pattern (9.3%). Ground-truthing of model outputs revealed that the odds of an animal being seropositive for RVFV when sampled from areas predicted to be most suitable for RVF occurrence were twice the odds of an animal sampled from areas least suitable for RVF occurrence (95% CI: 1.43, 2.76, p < 0.001). Conclusion/Significance The regions in the northern and central-eastern Tanzania were more suitable for RVF occurrence than the rest of the regions in the country. The modelled suitable habitat is characterised by impermeable soils, moderate precipitation in the wettest quarter, high livestock density and a bimodal rainfall pattern. The findings of this study should provide guidance for the design of appropriate RVF surveillance, prevention and control strategies which target areas with

Culex pipiens, an experimental efficient vector of West Nile and Rift Valley fever viruses in the Maghreb region.

Directory of Open Access Journals (Sweden)

Fadila Amraoui

Full Text Available West Nile fever (WNF and Rift Valley fever (RVF are emerging diseases causing epidemics outside their natural range of distribution. West Nile virus (WNV circulates widely and harmlessly in the old world among birds as amplifying hosts, and horses and humans as accidental dead-end hosts. Rift Valley fever virus (RVFV re-emerges periodically in Africa causing massive outbreaks. In the Maghreb, eco-climatic and entomologic conditions are favourable for WNV and RVFV emergence. Both viruses are transmitted by mosquitoes belonging to the Culex pipiens complex. We evaluated the ability of different populations of Cx. pipiens from North Africa to transmit WNV and the avirulent RVFV Clone 13 strain. Mosquitoes collected in Algeria, Morocco, and Tunisia during the summer 2010 were experimentally infected with WNV and RVFV Clone 13 strain at titers of 10(7.8 and 10(8.5 plaque forming units/mL, respectively. Disseminated infection and transmission rates were estimated 14-21 days following the exposure to the infectious blood-meal. We show that 14 days after exposure to WNV, all mosquito st developed a high disseminated infection and were able to excrete infectious saliva. However, only 69.2% of mosquito strains developed a disseminated infection with RVFV Clone 13 strain, and among them, 77.8% were able to deliver virus through saliva. Thus, Cx. pipiens from the Maghreb are efficient experimental vectors to transmit WNV and to a lesser extent, RVFV Clone 13 strain. The epidemiologic importance of our findings should be considered in the light of other parameters related to mosquito ecology and biology.

Wind Regimes in Complex Terrain of the Great Valley of Eastern Tennessee

Energy Technology Data Exchange (ETDEWEB)

Birdwell, Kevin R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2011-05-01

This research was designed to provide an understanding of physical wind mechanisms within the complex terrain of the Great Valley of Eastern Tennessee to assess the impacts of regional air flow with regard to synoptic and mesoscale weather changes, wind direction shifts, and air quality. Meteorological data from 2008 2009 were analyzed from 13 meteorological sites along with associated upper level data. Up to 15 ancillary sites were used for reference. Two-step complete linkage and K-means cluster analyses, synoptic weather studies, and ambient meteorological comparisons were performed to generate hourly wind classifications. These wind regimes revealed seasonal variations of underlying physical wind mechanisms (forced channeled, vertically coupled, pressure-driven, and thermally-driven winds). Synoptic and ambient meteorological analysis (mixing depth, pressure gradient, pressure gradient ratio, atmospheric and surface stability) suggested up to 93% accuracy for the clustered results. Probabilistic prediction schemes of wind flow and wind class change were developed through characterization of flow change data and wind class succession. Data analysis revealed that wind flow in the Great Valley was dominated by forced channeled winds (45 67%) and vertically coupled flow (22 38%). Down-valley pressure-driven and thermally-driven winds also played significant roles (0 17% and 2 20%, respectively), usually accompanied by convergent wind patterns (15 20%) and large wind direction shifts, especially in the Central/Upper Great Valley. The behavior of most wind regimes was associated with detectable pressure differences between the Lower and Upper Great Valley. Mixing depth and synoptic pressure gradients were significant contributors to wind pattern behavior. Up to 15 wind classes and 10 sub-classes were identified in the Central Great Valley with 67 joined classes for the Great Valley at-large. Two-thirds of Great Valley at-large flow was defined by 12 classes. Winds

A network-based meta-population approach to model Rift Valley fever epidemics.

Science.gov (United States)

Xue, Ling; Scott, H Morgan; Cohnstaedt, Lee W; Scoglio, Caterina

2012-08-07

Rift Valley fever virus (RVFV) has been expanding its geographical distribution with important implications for both human and animal health. The emergence of Rift Valley fever (RVF) in the Middle East, and its continuing presence in many areas of Africa, has negatively impacted both medical and veterinary infrastructures and human morbidity, mortality, and economic endpoints. Furthermore, worldwide attention should be directed towards the broader infection dynamics of RVFV, because suitable host, vector and environmental conditions for additional epidemics likely exist on other continents; including Asia, Europe and the Americas. We propose a new compartmentalized model of RVF and the related ordinary differential equations to assess disease spread in both time and space; with the latter driven as a function of contact networks. Humans and livestock hosts and two species of vector mosquitoes are included in the model. The model is based on weighted contact networks, where nodes of the networks represent geographical regions and the weights represent the level of contact between regional pairings for each set of species. The inclusion of human, animal, and vector movements among regions is new to RVF modeling. The movement of the infected individuals is not only treated as a possibility, but also an actuality that can be incorporated into the model. We have tested, calibrated, and evaluated the model using data from the recent 2010 RVF outbreak in South Africa as a case study; mapping the epidemic spread within and among three South African provinces. An extensive set of simulation results shows the potential of the proposed approach for accurately modeling the RVF spreading process in additional regions of the world. The benefits of the proposed model are twofold: not only can the model differentiate the maximum number of infected individuals among different provinces, but also it can reproduce the different starting times of the outbreak in multiple locations

Identification of Rift Valley Fever Virus Nucleocapsid Protein-RNA Binding Inhibitors Using a High-Throughput Screening Assay

OpenAIRE

Ellenbecker, Mary; Lanchy, Jean-Marc; Lodmell, J. Stephen

2012-01-01

Rift Valley fever virus (RVFV) is an emerging infectious pathogen that causes severe disease in humans and livestock and has the potential for global spread. Currently, there is no proven effective treatment for RVFV infection and there is no licensed vaccine. Inhibition of RNA binding to the essential viral nucleocapsid (N) protein represents a potential anti-viral therapeutic strategy because all of the functions performed by N during infection involve RNA binding. To target this interactio...

Rift Valley fever virus seroprevalence in human rural populations of Gabon.

Directory of Open Access Journals (Sweden)

Xavier Pourrut

Full Text Available BACKGROUND: Rift Valley fever (RVF is a mosquito-borne viral zoonosis caused by a phlebovirus and transmitted by Aedes mosquitoes. Humans can also be infected through direct contact with blood (aerosols or tissues (placenta, stillborn of infected animals. Although severe clinical cases can be observed, infection with RVF virus (RVFV in humans is, in most cases, asymptomatic or causes a febrile illness without serious symptoms. In small ruminants RVFV mainly causes abortion and neonatal death. The distribution of RVFV has been well documented in many African countries, particularly in the north (Egypt, Sudan, east (Kenya, Tanzania, Somalia, west (Senegal, Mauritania and south (South Africa, but also in the Indian Ocean (Madagascar, Mayotte and the Arabian Peninsula. In contrast, the prevalence of RVFV has rarely been investigated in central African countries. METHODOLOGY/PRINCIPAL FINDINGS: We therefore conducted a large serological survey of rural populations in Gabon, involving 4,323 individuals from 212 randomly selected villages (10.3% of all Gabonese villages. RVFV-specific IgG was found in a total of 145 individuals (3.3% suggesting the wide circulation of Rift Valley fever virus in Gabon. The seroprevalence was significantly higher in the lakes region than in forest and savannas zones, with respective rates of 8.3%, 2.9% and 2.2%. In the lakes region, RVFV-specific IgG was significantly more prevalent in males than in females (respectively 12.8% and 3.8% and the seroprevalence increased gradually with age in males but not in females. CONCLUSIONS/SIGNIFICANCE: Although RVFV was suggested to circulate at a relatively high level in Gabon, no outbreaks or even isolated cases have been documented in the country. The higher prevalence in the lakes region is likely to be driven by specific ecologic conditions favorable to certain mosquito vector species. Males may be more at risk of infection than females because they spend more time farming and

Hydrogeology of the Ramapo River-Woodbury Creek valley-fill aquifer system and adjacent areas in eastern Orange County, New York

Science.gov (United States)

Heisig, Paul M.

2015-01-01

The hydrogeology of the valley-fill aquifer system and surrounding watershed areas was investigated within a 23-mile long, fault-controlled valley in eastern Orange County, New York. Glacial deposits form a divide within the valley that is drained to the north by Woodbury Creek and is drained to the south by the Ramapo River. Surficial geology, extent and saturated thickness of sand and gravel aquifers, extent of confining units, bedrock-surface elevation beneath valleys, major lineaments, and the locations of wells for which records are available were delineated on an interactive map.

Impact of Global Climate on Rift Valley Fever and other Vector-borne Disease Outbreaks

Science.gov (United States)

Linthicum, K. J.

2017-12-01

Rift Valley fever is a viral disease of animals and humans in Africa and the Middle East that is transmitted by mosquitoes. Since the virus was first isolated in Kenya in 1930 it has caused significant impact to animal and human health and national economies, and it is of concern to the international agricultural and public health community. In this presentation we will describe the (1) ecology of disease transmission as it relates to climate, (2) the impact of climate and other environmental conditions on outbreaks, (3) the ability to use global climate information to predict outbreaks, (4) effective response activities, and (4) the potential to mitigate globalization.

Common host-derived chemicals increase catches of disease-transmitting mosquitoes and can improve early warning systems for rift valley fever virus

Science.gov (United States)

Rift Valley fever (RVF), a mosquito-borne zoonosis, is a major public health problem in sub-Saharan Africa. The emergence and re-emergence of the disease in the last 20 years especially in East Africa, poses a looming health threat which is likely to spread to beyond Africa. This threat is exacerbat...

Flinders Island Spotted Fever Rickettsioses Caused by “marmionii” Strain of Rickettsia honei, Eastern Australia

Science.gov (United States)

Unsworth, Nathan B.; Graves, Stephen R.; Faa, Antony G.; Cox, G. Erika; Dyer, John R.; Boutlis, Craig S.; Lane, Amanda M.; Shaw, Matthew D.; Robson, Jennifer; Nissen, Michael D.

2007-01-01

Australia has 4 rickettsial diseases: murine typhus, Queensland tick typhus, Flinders Island spotted fever, and scrub typhus. We describe 7 cases of a rickettsiosis, with an acute onset and symptoms of fever (100%), headache (71%), arthralgia (43%), myalgia (43%), cough (43%), maculopapular/petechial rash (43%), nausea (29%), pharyngitis (29%), lymphadenopathy (29%), and eschar (29%). Cases were most prevalent in autumn and from eastern Australia, including Queensland, Tasmania, and South Australia. One patient had a history of tick bite (Haemaphysalis novaeguineae). An isolate shared 99.2%, 99.8%, 99.8%, 99.9%, and 100% homology with the 17 kDa, ompA, gltA, 16S rRNA, and Sca4 genes, respectively, of Rickettsia honei. This Australian rickettsiosis has similar symptoms to Flinders Island spotted fever, and the strain is genetically related to R. honei. It has been designated the “marmionii” strain of R. honei, in honor of Australian physician and scientist Barrie Marmion. PMID:17553271

Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania

OpenAIRE

Mweya, Clement N.; Kimera, Sharadhuli I.; Mellau, Lesakit S. B.; Mboera, Leonard E. G.

2015-01-01

Background: Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. Objective: To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. Methods: A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mos...

Blood Meal Analysis of and Virus Detection in Mosquitoes Collected during a Rift Valley fever Epizootic/Epidemic: Implications for epidemic disease transmission dynamics

Science.gov (United States)

Rift Valley fever (RVF) is a zoonosis of domestic ruminants in Africa. Bloodfed mosquitoes collected during the 2006-2007 RVF outbreak in Kenya were analyzed to determine the virus infection status and animal source of the bloodmeals. Bloodmeals from individual mosquito abdomens were screened for v...

Ultrastructural study of Rift Valley fever virus in the mouse model

Energy Technology Data Exchange (ETDEWEB)

Reed, Christopher; Steele, Keith E.; Honko, Anna; Shamblin, Joshua; Hensley, Lisa E. [United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD (United States); Smith, Darci R., E-mail: darci.smith1@us.army.mil [United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD (United States)

2012-09-15

Detailed ultrastructural studies of Rift Valley fever virus (RVFV) in the mouse model are needed to develop and characterize a small animal model of RVF for the evaluation of potential vaccines and therapeutics. In this study, the ultrastructural features of RVFV infection in the mouse model were analyzed. The main changes in the liver included the presence of viral particles in hepatocytes and hepatic stem cells accompanied by hepatocyte apoptosis. However, viral particles were observed rarely in the liver; in contrast, particles were extremely abundant in the CNS. Despite extensive lymphocytolysis, direct evidence of viral replication was not observed in the lymphoid tissue. These results correlate with the acute-onset hepatitis and delayed-onset encephalitis that are dominant features of severe human RVF, but suggest that host immune-mediated mechanisms contribute significantly to pathology. The results of this study expand our knowledge of RVFV-host interactions and further characterize the mouse model of RVF.

Ultrastructural study of Rift Valley fever virus in the mouse model

International Nuclear Information System (INIS)

Reed, Christopher; Steele, Keith E.; Honko, Anna; Shamblin, Joshua; Hensley, Lisa E.; Smith, Darci R.

2012-01-01

Detailed ultrastructural studies of Rift Valley fever virus (RVFV) in the mouse model are needed to develop and characterize a small animal model of RVF for the evaluation of potential vaccines and therapeutics. In this study, the ultrastructural features of RVFV infection in the mouse model were analyzed. The main changes in the liver included the presence of viral particles in hepatocytes and hepatic stem cells accompanied by hepatocyte apoptosis. However, viral particles were observed rarely in the liver; in contrast, particles were extremely abundant in the CNS. Despite extensive lymphocytolysis, direct evidence of viral replication was not observed in the lymphoid tissue. These results correlate with the acute-onset hepatitis and delayed-onset encephalitis that are dominant features of severe human RVF, but suggest that host immune-mediated mechanisms contribute significantly to pathology. The results of this study expand our knowledge of RVFV–host interactions and further characterize the mouse model of RVF.

Neutralizing antibodies against flaviviruses, Babanki virus, and Rift Valley fever virus in Ugandan bats.

Science.gov (United States)

Kading, Rebekah C; Kityo, Robert M; Mossel, Eric C; Borland, Erin M; Nakayiki, Teddie; Nalikka, Betty; Nyakarahuka, Luke; Ledermann, Jeremy P; Panella, Nicholas A; Gilbert, Amy T; Crabtree, Mary B; Peterhans, Julian Kerbis; Towner, Jonathan S; Amman, Brian R; Sealy, Tara K; Nichol, Stuart T; Powers, Ann M; Lutwama, Julius J; Miller, Barry R

2018-01-01

Introduction: A number of arboviruses have previously been isolated from naturally-infected East African bats, however the role of bats in arbovirus maintenance is poorly understood. The aim of this study was to investigate the exposure history of Ugandan bats to a panel of arboviruses. Materials and methods: Insectivorous and fruit bats were captured from multiple locations throughout Uganda during 2009 and 2011-2013. All serum samples were tested for neutralizing antibodies against West Nile virus (WNV), yellow fever virus (YFV), dengue 2 virus (DENV-2), Zika virus (ZIKV), Babanki virus (BBKV), and Rift Valley fever virus (RVFV) by plaque reduction neutralization test (PRNT). Sera from up to 626 bats were screened for antibodies against each virus. Results and Discussion:  Key findings include the presence of neutralizing antibodies against RVFV in 5/52 (9.6%) of little epauletted fruit bats ( Epomophorus labiatus ) captured from Kawuku and 3/54 (5.6%) Egyptian rousette bats from Kasokero cave. Antibodies reactive to flaviviruses were widespread across bat taxa and sampling locations. Conclusion: The data presented demonstrate the widespread exposure of bats in Uganda to arboviruses, and highlight particular virus-bat associations that warrant further investigation.

Rift Valley Fever Risk Map Model and Seroprevalence in Selected Wild Ungulates and Camels from Kenya

Science.gov (United States)

Britch, Seth C.; Binepal, Yatinder S.; Ruder, Mark G.; Kariithi, Henry M.; Linthicum, Kenneth J.; Anyamba, Assaf; Small, Jennifer L.; Tucker, Compton J.; Ateya, Leonard O.; Oriko, Abuu A.;

Rift Valley fever virus NSS gene expression correlates with a defect in nuclear mRNA export.

Science.gov (United States)

Copeland, Anna Maria; Van Deusen, Nicole M; Schmaljohn, Connie S

2015-12-01

We investigated the localization of host mRNA during Rift Valley fever virus (RVFV) infection. Fluorescence in situ hybridization revealed that infection with RVFV altered the localization of host mRNA. mRNA accumulated in the nuclei of RVFV-infected but not mock-infected cells. Further, overexpression of the NSS gene, but not the N, GN or NSM genes correlated with mRNA nuclear accumulation. Nuclear accumulation of host mRNA was not observed in cells infected with a strain of RVFV lacking the gene encoding NSS, confirming that expression of NSS is likely responsible for this phenomenon. Published by Elsevier Inc.

Relating coccidioidomycosis (valley fever) incidence to soil moisture conditions.

Science.gov (United States)

Coopersmith, E J; Bell, J E; Benedict, K; Shriber, J; McCotter, O; Cosh, M H

2017-04-17

Coccidioidomycosis (also called Valley fever) is caused by a soilborne fungus, Coccidioides spp. , in arid regions of the southwestern United States. Though some who develop infections from this fungus remain asymptomatic, others develop respiratory disease as a consequence. Less commonly, severe illness and death can occur when the infection spreads to other regions of the body. Previous analyses have attempted to connect the incidence of coccidioidomycosis to broadly available climatic measurements, such as precipitation or temperature. However, with the limited availability of long-term, in situ soil moisture data sets, it has not been feasible to perform a direct analysis of the relationships between soil moisture levels and coccidioidomycosis incidence on a larger temporal and spatial scale. Utilizing in situ soil moisture gauges throughout the southwest from the U.S. Climate Reference Network and a model with which to extend those estimates, this work connects periods of higher and lower soil moisture in Arizona and California between 2002 and 2014 to the reported incidence of coccidioidomycosis. The results indicate that in both states, coccidioidomycosis incidence is related to soil moisture levels from previous summers and falls. Stated differently, a higher number of coccidioidomycosis cases are likely to be reported if previous bands of months have been atypically wet or dry, depending on the location.

Exploratory Study on Pathogenesis of Far-Eastern Spotted Fever

Science.gov (United States)

Duan, Changsong; Meng, Yanfen; Wang, Xile; Xiong, Xiaolu; Wen, Bohai

2011-01-01

Far-eastern spotted fever is an emerging disease caused by Rickettsia heilongjiangensis, a tick-borne obligate intracellular bacterium. In this study, R. heilongjiangensis was used to infect BALB/c mice by inoculation of retro-orbital venous plexus to imitate a blood infection caused by tick biting. We found that R. heilongjiangensis rapidly entered the circulation for systemic dissemination and the pathogen existed in liver, spleen, lungs, and brain of the mice at least 9 days post-infection (p.i.). Severe pathological lesions were observed in liver, lungs, and brain at Day 6 p.i. In addition, the elevated levels of inflammatory cytokines, including interferon-γ, tumor necrosis factor, and CC chemokine, were detected in the infected organs at Day 3 p.i. Our results reveal that R. heilongjiangensis may cause an infection in BALB/c mice and the pathological lesions in the infected mice are associated with host inflammatory response induced by R. heilongjiangensis. PMID:21896812

Infection of inbred rat strains with Rift Valley fever virus: development of a congenic resistant strain and observations on age-dependence of resistance.

Science.gov (United States)

Anderson, G W; Rosebrock, J A; Johnson, A J; Jennings, G B; Peters, C J

1991-05-01

A congenic rat strain (WF.LEW) was derived from the susceptible Wistar-Furth (WF) (background strain) and the resistant LEW (donor strain) inbred strains and was used to evaluate the phenotypic expression of a dominant Mendelian gene that confers resistance to fatal hepatic disease caused by the ZH501 strain of Rift Valley fever virus (RVFV). Resistance to hepatic disease developed gradually with age, with full expression at approximately 10 weeks in the WF.LEW and LEW rat strains. The ZH501 strain caused fatal hepatitis in WF rats regardless of age. However, resistance to the SA75 RVFV strain (relatively non-pathogenic for adult rats), was age- and dose-dependent in both WF and LEW rats. The resistance gene transferred to the newly derived WF.LEW congenic rat strain appears to amplify age-dependent resistance of adult rats, resulting in protection against fatal hepatic disease caused by the virulent ZH501 strain. The congenic rat strain will be a valuable asset in elucidating the mechanism of resistance to Rift Valley fever virus governed by the dominant Mendelian gene.

Rift Valley fever virus epidemic in Kenya, 2006/2007: the entomologic investigations.

Science.gov (United States)

Sang, Rosemary; Kioko, Elizabeth; Lutomiah, Joel; Warigia, Marion; Ochieng, Caroline; O'Guinn, Monica; Lee, John S; Koka, Hellen; Godsey, Marvin; Hoel, David; Hanafi, Hanafi; Miller, Barry; Schnabel, David; Breiman, Robert F; Richardson, Jason

2010-08-01

In December 2006, Rift Valley fever (RVF) was diagnosed in humans in Garissa Hospital, Kenya and an outbreak reported affecting 11 districts. Entomologic surveillance was performed in four districts to determine the epidemic/epizootic vectors of RVF virus (RVFV). Approximately 297,000 mosquitoes were collected, 164,626 identified to species, 72,058 sorted into 3,003 pools and tested for RVFV by reverse transcription-polymerase chain reaction. Seventy-seven pools representing 10 species tested positive for RVFV, including Aedes mcintoshi/circumluteolus (26 pools), Aedes ochraceus (23 pools), Mansonia uniformis (15 pools); Culex poicilipes, Culex bitaeniorhynchus (3 pools each); Anopheles squamosus, Mansonia africana (2 pools each); Culex quinquefasciatus, Culex univittatus, Aedes pembaensis (1 pool each). Positive Ae. pembaensis, Cx. univittatus, and Cx. bitaeniorhynchus was a first time observation. Species composition, densities, and infection varied among districts supporting hypothesis that different mosquito species serve as epizootic/epidemic vectors of RVFV in diverse ecologies, creating a complex epidemiologic pattern in East Africa.

Serologic evidence of exposure to Rift Valley fever virus detected in Tunisia

Directory of Open Access Journals (Sweden)

A. Bosworth

2016-01-01

Full Text Available Rift Valley fever virus (RVFv is capable of causing dramatic outbreaks amongst economically important animal species and is capable of causing severe symptoms and mortality in humans. RVFv is known to circulate widely throughout East Africa; serologic evidence of exposure has also been found in some northern African countries, including Mauritania. This study aimed to ascertain whether RVFv is circulating in regions beyond its known geographic range. Samples from febrile patients (n=181 and nonfebrile healthy agricultural and slaughterhouse workers (n=38 were collected during the summer of 2014 and surveyed for exposure to RVFv by both serologic tests and PCR. Of the 219 samples tested, 7.8% of nonfebrile participants showed immunoglobulin G reactivity to RVFv nucleoprotein and 8.3% of febrile patients showed immunoglobulin M reactivity, with the latter samples indicating recent exposure to the virus. Our results suggest an active circulation of RVFv and evidence of human exposure in the population of Tunisia.

Integrated Analysis of Environment, Cattle and Human Serological Data: Risks and Mechanisms of Transmission of Rift Valley Fever in Madagascar.

Science.gov (United States)

Olive, Marie-Marie; Chevalier, Véronique; Grosbois, Vladimir; Tran, Annelise; Andriamandimby, Soa-Fy; Durand, Benoit; Ravalohery, Jean-Pierre; Andriamamonjy, Seta; Rakotomanana, Fanjasoa; Rogier, Christophe; Heraud, Jean-Michel

2016-07-01

Rift Valley fever (RVF) is a vector-borne disease affecting ruminants and humans. Madagascar was heavily affected by RVF in 2008-2009, with evidence of a large and heterogeneous spread of the disease. The identification of at-risk environments is essential to optimize the available resources by targeting RVF surveillance in Madagascar. Herein, the objectives of our study were: (i) to identify the environmental factors and areas favorable to RVF transmission to both cattle and human and (ii) to identify human behaviors favoring human infections in Malagasy contexts. First, we characterized the environments of Malagasy communes using a Multiple Factor Analysis (MFA). Then, we analyzed cattle and human serological data collected at national level using Generalized Linear Mixed Models, with the individual serological status (cattle or human) as the response, and MFA factors, as well as other potential risk factors (cattle density, human behavior) as explanatory variables. Cattle and human seroprevalence rates were positively associated to humid environments (p<0.001). Areas with high cattle density were at risk (p<0.01; OR = 2.6). Furthermore, our analysis showed that frequent contact with raw milk contributed to explain human infection (OR = 1.6). Finally, our study highlighted the eastern-coast, western and north-western parts as high-risk areas for RVF transmission in cattle. Our integrated approach analyzing environmental, cattle and human datasets allow us to bring new insight on RVF transmission patterns in Madagascar. The association between cattle seroprevalence, humid environments and high cattle density suggests that concomitant vectorial and direct transmissions are critical to maintain RVF enzootic transmission. Additionally, in the at-risk humid environment of the western, north-western and the eastern-coast areas, suitable to Culex and Anopheles mosquitoes, vectorial transmission probably occurs in both cattle and human. The relative contribution of

Integrated Analysis of Environment, Cattle and Human Serological Data: Risks and Mechanisms of Transmission of Rift Valley Fever in Madagascar.

Directory of Open Access Journals (Sweden)

Marie-Marie Olive

2016-07-01

Full Text Available Rift Valley fever (RVF is a vector-borne disease affecting ruminants and humans. Madagascar was heavily affected by RVF in 2008-2009, with evidence of a large and heterogeneous spread of the disease. The identification of at-risk environments is essential to optimize the available resources by targeting RVF surveillance in Madagascar. Herein, the objectives of our study were: (i to identify the environmental factors and areas favorable to RVF transmission to both cattle and human and (ii to identify human behaviors favoring human infections in Malagasy contexts.First, we characterized the environments of Malagasy communes using a Multiple Factor Analysis (MFA. Then, we analyzed cattle and human serological data collected at national level using Generalized Linear Mixed Models, with the individual serological status (cattle or human as the response, and MFA factors, as well as other potential risk factors (cattle density, human behavior as explanatory variables. Cattle and human seroprevalence rates were positively associated to humid environments (p<0.001. Areas with high cattle density were at risk (p<0.01; OR = 2.6. Furthermore, our analysis showed that frequent contact with raw milk contributed to explain human infection (OR = 1.6. Finally, our study highlighted the eastern-coast, western and north-western parts as high-risk areas for RVF transmission in cattle.Our integrated approach analyzing environmental, cattle and human datasets allow us to bring new insight on RVF transmission patterns in Madagascar. The association between cattle seroprevalence, humid environments and high cattle density suggests that concomitant vectorial and direct transmissions are critical to maintain RVF enzootic transmission. Additionally, in the at-risk humid environment of the western, north-western and the eastern-coast areas, suitable to Culex and Anopheles mosquitoes, vectorial transmission probably occurs in both cattle and human. The relative contribution

The understanding of the formation of valleys and its implication on site characterization: Moredalen and Pukedalen, south-eastern Sweden

International Nuclear Information System (INIS)

Tiren, Sven A.; Waenstedt, Stefan; Straeng, Thomas

2010-11-01

In south-eastern Sweden, there are a number of over-deepened narrow valleys, more than 20 m deep, formed in Precambrian bedrock located above the highest post-glacial shoreline. Canyon-like valleys, called 'kursu' or kursu valleys, are generally interpreted to be formed by glaciofluvial erosion. An example of such a valley is Moredalen, a canyon in the Fennoscandian Shield, which has an implication on site selection for radioactive waste disposal. There are also more open over-deepened valleys along which sub-glacial flow has occurred, e.g. Pukedalen. The main part of this paper discusses a combined geological and geophysical investigation of Moredalen, with the aim to investigate possible reasons for the formation of such an unusual feature formed in acid vulcanite and foliated tonalitic to granodioritic rocks. Moredalen is a marked, approximately 7 km long, E-W striking valley that cuts through a plateau (c. 140 m a.s.l.), and an elevated block of the sub-Cambrian peneplain. Glaciofluvial sediments can be found up-streams where the canyon widens to the west. Just east of the valley is a larger delta deposited at the highest post-glacial shoreline (c. 105 m a.s.l). Further east of, and in line with the Moredalen valley there is an esker. Rock debris in the valley is angular. Pukedalen is a northwest-southeast trending valley incised in massive granite. The valley is in its northern parts relatively open and becomes narrow in its south-eastern part having partly a vertical south-western wall. Rock surfaces are smooth along the valley and rock debris in the valley consists generally of rounded blocks. In line with Pukedalen, on both sides at great distances though, there are eskers. Geomorphological features of this kind indicate certain characteristics of the bedrock that need to be considered during safety analysis of repositories for nuclear waste. The distinct weakness zones along which the kursu-valleys are formed create prominent transport paths for

The understanding of the formation of valleys and its implication on site characterization: Moredalen and Pukedalen, south-eastern Sweden

Energy Technology Data Exchange (ETDEWEB)

Tiren, Sven A.; Waenstedt, Stefan; Straeng, Thomas (GEOSIGMA AB (Sweden))

2010-11-15

In south-eastern Sweden, there are a number of over-deepened narrow valleys, more than 20 m deep, formed in Precambrian bedrock located above the highest post-glacial shoreline. Canyon-like valleys, called 'kursu' or kursu valleys, are generally interpreted to be formed by glaciofluvial erosion. An example of such a valley is Moredalen, a canyon in the Fennoscandian Shield, which has an implication on site selection for radioactive waste disposal. There are also more open over-deepened valleys along which sub-glacial flow has occurred, e.g. Pukedalen. The main part of this paper discusses a combined geological and geophysical investigation of Moredalen, with the aim to investigate possible reasons for the formation of such an unusual feature formed in acid vulcanite and foliated tonalitic to granodioritic rocks. Moredalen is a marked, approximately 7 km long, E-W striking valley that cuts through a plateau (c. 140 m a.s.l.), and an elevated block of the sub-Cambrian peneplain. Glaciofluvial sediments can be found up-streams where the canyon widens to the west. Just east of the valley is a larger delta deposited at the highest post-glacial shoreline (c. 105 m a.s.l). Further east of, and in line with the Moredalen valley there is an esker. Rock debris in the valley is angular. Pukedalen is a northwest-southeast trending valley incised in massive granite. The valley is in its northern parts relatively open and becomes narrow in its south-eastern part having partly a vertical south-western wall. Rock surfaces are smooth along the valley and rock debris in the valley consists generally of rounded blocks. In line with Pukedalen, on both sides at great distances though, there are eskers. Geomorphological features of this kind indicate certain characteristics of the bedrock that need to be considered during safety analysis of repositories for nuclear waste. The distinct weakness zones along which the kursu-valleys are formed create prominent transport paths for

Rift Valley fever in Kenya: history of epizootics and identification of vulnerable districts.

Science.gov (United States)

Murithi, R M; Munyua, P; Ithondeka, P M; Macharia, J M; Hightower, A; Luman, E T; Breiman, R F; Njenga, M Kariuki

2011-03-01

Since Kenya first reported Rift Valley fever (RVF)-like disease in livestock in 1912, the country has reported the most frequent epizootics of RVF disease. To determine the pattern of disease spread across the country after its introduction in 1912, and to identify regions vulnerable to the periodic epizootics, annual livestock disease records at the Department of Veterinary Services from 1910 to 2007 were analysed in order to document the number and location of RVF-infected livestock herds. A total of 38/69 (55%) administrative districts in the country had reported RVF epizootics by the end of 2007. During the 1912-1950 period, the disease was confined to a district in Rift Valley province that is prone to flooding and where livestock were raised in proximity with wildlife. Between 1951 and 2007, 11 national RVF epizootics were recorded with an average inter-epizootic period of 3·6 years (range 1-7 years); in addition, all epizootics occurred in years when the average annual rainfall increased by more than 50% in the affected districts. Whereas the first two national epizootics in 1951 and 1955 were confined to eight districts in the Rift Valley province, there was a sustained epizootic between 1961 and 1964 that spread the virus to over 30% of the districts across six out of eight provinces. The Western and Nyanza provinces, located on the southwestern region of the country, had never reported RVF infections by 2007. The probability of a district being involved in a national epizootic was fivefold higher (62%) in districts that had previously reported disease compared to districts that had no prior disease activity (11%). These findings suggests that once introduced into certain permissive ecologies, the RVF virus becomes enzootic, making the region vulnerable to periodic epizootics that were probably precipitated by amplification of resident virus associated with heavy rainfall and flooding.

Inter-epidemic acquisition of Rift Valley fever virus in humans in Tanzania.

Directory of Open Access Journals (Sweden)

Robert David Sumaye

2015-02-01

Full Text Available BACKGROUND: In East Africa, epidemics of Rift Valley fever (RVF occur in cycles of 5-15 years following unusually high rainfall. RVF transmission during inter-epidemic periods (IEP generally passes undetected in absence of surveillance in mammalian hosts and vectors. We studied IEP transmission of RVF and evaluated the demographic, behavioural, occupational and spatial determinants of past RVF infection. METHODOLOGY: Between March and August 2012 we collected blood samples, and administered a risk factor questionnaire among 606 inhabitants of 6 villages in the seasonally inundated Kilombero Valley, Tanzania. ELISA tests were used to detect RVFV IgM and IgG antibodies in serum samples. Risk factors were examined by mixed effects logistic regression. FINDINGS: RVF virus IgM antibodies, indicating recent RVFV acquisition, were detected in 16 participants, representing 2.6% overall and in 22.5% of inhibition ELISA positives (n = 71. Four of 16 (25.0% IgM positives and 11/71 (15.5% of individuals with inhibition ELISA sero-positivity reported they had had no previous contact with host animals. Sero-positivity on inhibition ELISA was 11.7% (95% CI 9.2-14.5 and risk was elevated with age (odds ratio (OR 1.03 per year; 95% CI 1.01-1.04, among milkers (OR 2.19; 95% CI 1.23-3.91, and individuals eating raw meat (OR 4.17; 95% CI 1.18-14.66. Households keeping livestock had a higher probability of having members with evidence of past infection (OR = 3.04, 95% CI = 1.42-6.48 than those that do not keep livestock. CONCLUSION: There is inter-epidemic acquisition of RVFV in Kilombero Valley inhabitants. In the wake of declining malaria incidence, these findings underscore the need for clinicians to consider RVF in the differential diagnosis for febrile illnesses. Several types of direct contact with livestock are important risk factors for past infection with RVFV in this study's population. However, at least part of RVFV transmission appears to have occurred

Early-to-middle Holocene sea-level fluctuations, coastal progradation and the Neolithic occupations in Yaojiang valley of southern Hangzhou bay, eastern China

Science.gov (United States)

Liu, Y.; Sun, Q.; Fan, D.; Chen, Z.

2017-12-01

The formation of Holocene coast in eastern China provided material base for the development of Neolithic civilizations. The coastal Yaojiang valley of south Hangzhou bay was one of the examples where the well-known Neolithic Hemudu Culture (HC) of Eastern China initiated. Here, we studied the early-to-middle Holocene environment changes in relation to sea-level fluctuations on the basis of a serial of sediment cores based on a set of new Accelerator Mass Spectrometry radiocarbon (AMS 14C) chronology. The result indicated that relative sea-level rose rapidly in the Yaojiang valley at the early Holocene, reaching its maximum at ca. 8000-7800 cal yr BP and then decelerated at ca. 7800-7500 cal yr BP. The alluvial plain in Yaojiang valley began to form at the foothills first and then grew towards the valley center accompanying with the sea-level stabilization after ca. 7500 cal yr BP. This progressive progradation of alluvial plain would attract the early arrivals of foragers to dwell at the foothills to engaging in rice farming after ca.7000 cal yr BP and starting the epic Hemudu Culture. The HC people then move down to the valley center as more land became available thanks to sediment aggregation and progradation. The rise and development of HC were closely associated with the sea-level induced landscape changes in Yaojiang valley at the early-middle Holocene, and the unstable hydraulic condition in the valley after 5000 cal yr BP could be accountable for the cultural termination.

Presence of viral RNA and proteins in exosomes from the cellular clones resistant to Rift Valley Fever Virus infection.

Directory of Open Access Journals (Sweden)

Noor eAhsan

2016-02-01

Full Text Available Rift Valley Fever Virus (RVFV is a RNA virus that belongs to the genus Phlebovirus, family Bunyaviridae. It infects humans and livestock and causes Rift Valley fever. RVFV is considered an agricultural pathogen by the USDA, as it can cause up to 100% abortion in cattle and extensive death of newborns. In addition, it is designated as Category A pathogen by the CDC and the NIAID. In some human cases of RVFV infection, the virus causes fever, ocular damage, liver damage, hemorrhagic fever, and death. There are currently limited options for vaccine candidates, which include the MP-12 and clone 13 versions of RVFV. Viral infections often deregulate multiple cellular pathways that contribute to replication and host pathology. We have previously shown that latent HIV-1 and HTLV-1 infected cells secrete exosomes that contain short viral RNAs, limited number of genomic RNAs, and viral proteins. These exosomes largely target neighboring cells and activate the NF-кB pathway, leading to cell proliferation and overall better viral replication. In this manuscript, we studied the effects of exosome formation from RVFV infected cells and their function on recipient cells. We initially infected cells, isolated resistant clones, and further purified using dilution cloning. We then characterized these cells as resistant to new RVFV infection, but sensitive to other viral infections, including Venezuelan Equine Encephalitis Virus (VEEV. These clones contained normal markers (i.e. CD63 for exosomes and were able to activate the TLR pathway in recipient reporter cells. Interestingly, the exosome rich preparations, much like their host cell, contained viral RNA (L, M, and S genome. The RNAs were detected using qRT-PCR in both parental and exosomal preparations as well as in CD63 immunoprecipitates. Viral proteins such as N and a modified form of NSs were present in some of these exosomes. Finally, treatment of recipient cells (T- cells and monocytic cells showed

Rift Valley fever virus NSs inhibits host transcription independently of the degradation of dsRNA-dependent Protein Kinase PKR

OpenAIRE

Kalveram, Birte; Lihoradova, Olga; Indran, Sabarish V.; Lokugamage, Nandadeva; Head, Jennifer A.; Ikegami, Tetsuro

2012-01-01

Rift Valley fever virus (RVFV) encodes one major virulence factor, the NSs protein. NSs suppresses host general transcription, including interferon (IFN)-β mRNA synthesis, and promotes degradation of the dsRNA-dependent protein kinase (PKR). We generated a novel RVFV mutant (rMP12-NSsR173A) specifically lacking the function to promote PKR degradation. rMP12-NSsR173A infection induces early phosphorylation of eIF2α through PKR activation, while retaining the function to inhibit host general tr...

Large-scale gravity sliding in the Miocene Shadow Valley Supradetachment Basin, Eastern Mojave Desert, California

Science.gov (United States)

Davis, G. A.; Friedmann, S. J.

2005-12-01

The Miocene Shadow Valley basin in the eastern Mojave Desert of California developed above the active west-dipping Kingston Range-Halloran Hills extensional detachment fault system between 13.5 and ca. 7 mybp. Although mass-wasting processes are common phenomena in supradetachment basins, the Shadow Valley basin is an exceptional locale for the study of such processes, especially rock-avalanches and gravity sliding. A score of megabreccias, interpreted as rock-avalanche deposits, and half that number of very large (> 1 km 2, up to 200 m thick), internally intact gravity-driven slide sheets are interbedded with various sedimentary facies. The slide sheets, variably composed of Proterozoic crystalline rocks and Proterozoic, Paleozoic, and Tertiary sedimentary strata, moved across both depositional and erosional surfaces in the basin. Although the majority consist of Paleozoic carbonate rocks, the largest slide sheet, the Eastern Star crystalline allochthon, contains Proterozoic gneisses and their sedimentary cover and is now preserved as klippen atop Miocene lacustrine and alluvial fan deposits over an area > 40 km 2. Estimates of slide sheet runouts into the basin from higher eastern and northern source terranes range from approximately a few km to > 10 km; in most cases the exact provenances of the slide blocks are not known. The basal contacts of Shadow Valley slide sheets are characteristically knife sharp, show few signs of lithologic mixing of upper- and lower-plate rocks, and locally exhibit slickensided and striated, planar fault-like bases. Pronounced folding of overridden Miocene lacustrine and fan deposits beneath the Eastern Star allochthon extends to depths up to 40 m at widely scattered localities. We conclude that this slow moving slide sheet encountered isolated topographic asperities (hills) and that stress transfer across the basal slide surface produced folding of footwall strata. Synkinematic gypsum veins in footwall playa sediments, with fibers

Multilevel Methodology for Simulation of Spatio-Temporal Systems with Heterogeneous Activity; Application to Spread of Valley Fever Fungus

Science.gov (United States)

Jammalamadaka, Rajanikanth

2009-01-01

This report consists of a dissertation submitted to the faculty of the Department of Electrical and Computer Engineering, in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Graduate College, The University of Arizona, 2008. Spatio-temporal systems with heterogeneity in their structure and behavior have two major problems associated with them. The first one is that such complex real world systems extend over very large spatial and temporal domains and consume so many computational resources to simulate that they are infeasible to study with current computational platforms. The second one is that the data available for understanding such systems is limited because they are spread over space and time making it hard to obtain micro and macro measurements. This also makes it difficult to get the data for validation of their constituent processes while simultaneously considering their global behavior. For example, the valley fever fungus considered in this dissertation is spread over a large spatial grid in the arid Southwest and typically needs to be simulated over several decades of time to obtain useful information. It is also hard to get the temperature and moisture data (which are two critical factors on which the survival of the valley fever fungus depends) at every grid point of the spatial domain over the region of study. In order to address the first problem, we develop a method based on the discrete event system specification which exploits the heterogeneity in the activity of the spatio-temporal system and which has been shown to be effective in solving relatively simple partial differential equation systems. The benefit of addressing the first problem is that it now makes it feasible to address the second problem. We address the second problem by making use of a multilevel methodology based on modeling and simulation and systems theory. This methodology helps us in the construction of models with different resolutions (base and

A multiple-tracer approach to understanding regional groundwater flow in the Snake Valley area of the eastern Great Basin, USA

International Nuclear Information System (INIS)

Gardner, Philip M.; Heilweil, Victor M.

2014-01-01

Highlights: • Age tracers and noble gases constrain intra- and inter-basin groundwater flow. • Tritium indicates modern (<60 yr) recharge occurring in all mountain areas. • Noble-gas data identify an important interbasin hydraulic discontinuity. • Further groundwater development may significantly impact Snake Valley springs. - Abstract: Groundwater in Snake Valley and surrounding basins in the eastern Great Basin province of the western United States is being targeted for large-scale groundwater extraction and export. Concern about declining groundwater levels and spring flows in western Utah as a result of the proposed groundwater withdrawals has led to efforts that have improved the understanding of this regional groundwater flow system. In this study, environmental tracers (δ 2 H, δ 18 O, 3 H, 14 C, 3 He, 4 He, 20 Ne, 40 Ar, 84 Kr, and 129 Xe) and major ions from 142 sites were evaluated to investigate groundwater recharge and flow-path characteristics. With few exceptions, δ 2 H and δ 18 O show that most valley groundwater has similar ratios to mountain springs, indicating recharge is dominated by relatively high-altitude precipitation. The spatial distribution of 3 H, terrigenic helium ( 4 He terr ), and 3 H/ 3 He ages shows that modern groundwater (<60 yr) in valley aquifers is found only in the western third of the study area. Pleistocene and late-Holocene groundwater is found in the eastern parts of the study area. The age of Pleistocene groundwater is supported by minimum adjusted radiocarbon ages of up to 32 ka. Noble gas recharge temperatures (NGTs) are generally 1–11 °C in Snake and southern Spring Valleys and >11 °C to the east of Snake Valley and indicate a hydraulic discontinuity between Snake and Tule Valleys across the northern Confusion Range. The combination of NGTs and 4 He terr shows that the majority of Snake Valley groundwater discharges as springs, evapotranspiration, and well withdrawals within Snake Valley rather than

Factors associated with severe human Rift Valley fever in Sangailu, Garissa County, Kenya.

Directory of Open Access Journals (Sweden)

A Desirée LaBeaud

2015-03-01

Full Text Available Mosquito-borne Rift Valley fever virus (RVFV causes acute, often severe, disease in livestock and humans. To determine the exposure factors and range of symptoms associated with human RVF, we performed a population-based cross-sectional survey in six villages across a 40 km transect in northeastern Kenya.A systematic survey of the total populations of six Northeastern Kenyan villages was performed. Among 1082 residents tested via anti-RVFV IgG ELISA, seroprevalence was 15% (CI95%, 13-17%. Prevalence did not vary significantly among villages. Subject age was a significant factor, with 31% (154/498 of adults seropositive vs. only 2% of children ≤15 years (12/583. Seroprevalence was higher among men (18% than women (13%. Factors associated with seropositivity included a history of animal exposure, non-focal fever symptoms, symptoms related to meningoencephalitis, and eye symptoms. Using cluster analysis in RVFV positive participants, a more severe symptom phenotype was empirically defined as having somatic symptoms of acute fever plus eye symptoms, and possibly one or more meningoencephalitic or hemorrhagic symptoms. Associated with this more severe disease phenotype were older age, village, recent illness, and loss of a family member during the last outbreak. In multivariate analysis, sheltering livestock (aOR = 3.5 CI95% 0.93-13.61, P = 0.065, disposing of livestock abortus (aOR = 4.11, CI95% 0.63-26.79, P = 0.14, and village location (P = 0.009 were independently associated with the severe disease phenotype.Our results demonstrate that a significant proportion of the population in northeastern Kenya has been infected with RVFV. Village and certain animal husbandry activities were associated with more severe disease. Older age, male gender, herder occupation, killing and butchering livestock, and poor visual acuity were useful markers for increased RVFV infection. Formal vision testing may therefore prove to be a helpful, low-technology tool

Landscape Genetics of Aedes mcintoshi (Diptera: Culicidae), an Important Vector of Rift Valley Fever Virus in Northeastern Kenya.

Science.gov (United States)

Campbell, Lindsay P; Alexander, Alana M

2017-09-01

Rift Valley fever virus (RVFV) is a vector-borne, zoonotic disease that affects humans, wild ungulates, and domesticated livestock in Africa and the Arabian Peninsula. Rift Valley fever virus exhibits interepizootic and epizootic phases, the latter defined by widespread virus occurrence in domesticated livestock. Kenya appears to be particularly vulnerable to epizootics, with 11 outbreaks occurring between 1951 and 2007. The mosquito species Aedes mcintoshi (subgenus Neomelaniconion) is an important primary vector for RVFV in Kenya. Here, we investigate associations between genetic diversity and differentiation of one regional subclade of Ae. mcintoshi in Northeastern Kenya with environmental variables, using a multivariate statistical approach. Using CO1 (cytochrome oxidase subunit 1) sequence data deposited in GenBank, we found no evidence of isolation by distance contributing to genetic differentiation across the study area. However, we did find significant CO1 subpopulation structure and associations with recent mean precipitation values. In addition, variation in genetic diversity across our seven sample sites was associated with both precipitation and percentage clay in the soil. The large number of haplotypes found in this data set indicates that a great deal of diversity remains unsampled in this region. Additional sampling across a larger geographic area, combined with next-generation sequencing approaches that better characterize the genome, would provide a more robust assessment of genetic diversity and differentiation. Further understanding of the genetic structure of Ae. mcintoshi could provide useful information regarding the potential for RVFV to spread across East African landscapes. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Nuclear relocalization of polyadenylate binding protein during rift valley fever virus infection involves expression of the NSs gene.

Science.gov (United States)

Copeland, Anna Maria; Altamura, Louis A; Van Deusen, Nicole M; Schmaljohn, Connie S

2013-11-01

Rift Valley fever virus (RVFV), an ambisense member of the family Bunyaviridae, genus Phlebovirus, is the causative agent of Rift Valley fever, an important zoonotic infection in Africa and the Middle East. Phlebovirus proteins are translated from virally transcribed mRNAs that, like host mRNA, are capped but, unlike host mRNAs, are not polyadenylated. Here, we investigated the role of PABP1 during RVFV infection of HeLa cells. Immunofluorescence studies of infected cells demonstrated a gross relocalization of PABP1 to the nucleus late in infection. Immunofluorescence microscopy studies of nuclear proteins revealed costaining between PABP1 and markers of nuclear speckles. PABP1 relocalization was sharply decreased in cells infected with a strain of RVFV lacking the gene encoding the RVFV nonstructural protein S (NSs). To determine whether PABP1 was required for RVFV infection, we measured the production of nucleocapsid protein (N) in cells transfected with small interfering RNAs (siRNAs) targeting PABP1. We found that the overall percentage of RVFV N-positive cells was not changed by siRNA treatment, indicating that PABP1 was not required for RVFV infection. However, when we analyzed populations of cells producing high versus low levels of PABP1, we found that the percentage of RVFV N-positive cells was decreased in cell populations producing physiologic levels of PABP1 and increased in cells with reduced levels of PABP1. Together, these results suggest that production of the NSs protein during RVFV infection leads to sequestration of PABP1 in the nuclear speckles, creating a state within the cell that favors viral protein production.

The nonstructural protein NSs induces a variable antibody response in domestic ruminants naturally infected with Rift Valley fever virus.

Science.gov (United States)

Fernandez, José-Carlos; Billecocq, Agnès; Durand, Jean Paul; Cêtre-Sossah, Catherine; Cardinale, Eric; Marianneau, Philippe; Pépin, Michel; Tordo, Noël; Bouloy, Michèle

2012-01-01

Rift Valley fever (RVF) is an emerging zoonosis in Africa which has spread to Egypt, the Arabian Peninsula, Madagascar, and Comoros. RVF virus (RVFV) (Bunyaviridae family, Phlebovirus genus) causes a wide range of symptoms in humans, from benign fever to fatal hemorrhagic fever. Ruminants are severely affected by the disease, which leads to a high rate of mortality in young animals and to abortions and teratogenesis in pregnant females. Diagnostic tests include virus isolation and genome or antibody detection. During RVFV infection, the nucleoprotein encapsidating the tripartite RNA genome is expressed in large amounts and raises a robust antibody response, while the envelope glycoproteins elicit neutralizing antibodies which play a major role in protection. Much less is known about the antigenicity/immunogenicity of the nonstructural protein NSs, which is a major virulence factor. Here we have developed a competitive enzyme-linked immunosorbent assay (ELISA) enabling detection of low levels of NSs-specific antibodies in naturally infected or vaccinated ruminants. Detection of the NSs antibodies was validated by Western blotting. Altogether, our data showed that the NSs antibodies were detected in only 55% of animals naturally infected by RVFV, indicating that NSs does not induce a consistently high immune response. These results are discussed in light of differentiation between infected and vaccinated animals (DIVA) tests distinguishing naturally infected animals and those vaccinated with NSs-defective vaccines.

Rift Valley fever virus: strategies for maintenance, survival and vertical transmission in mosquitoes.

Science.gov (United States)

Lumley, Sarah; Horton, Daniel L; Hernandez-Triana, Luis L M; Johnson, Nicholas; Fooks, Anthony R; Hewson, Roger

2017-05-01

Rift Valley fever virus (RVFV) is a mosquito-borne arbovirus causing severe disease in humans and ruminants. Spread of RVFV out of Africa has raised concerns that it could emerge in Europe or the USA. Virus persistence is dependent on successful infection of, replication in, and transmission to susceptible vertebrate and invertebrate hosts, modulated by virus-host and vector-virus interactions. The principal accepted theory for the long-term maintenance of RVFV involves vertical transmission (VT) of virus to mosquito progeny, with the virus surviving long inter-epizootic periods within the egg. This VT hypothesis, however, is yet to be comprehensively proven. Here, evidence for and against the VT of RVFV is reviewed along with the identification of factors limiting its detection in natural and experimental data. The observations of VT for other arboviruses in the genera Alphavirus, Flavivirus and Orthobunyavirus are discussed within the context of RVFV. The review concludes that VT of RVFV is likely but that current data are insufficient to irrefutably prove this hypothesis.

Hydrogeology of Valley-Fill Aquifers and Adjacent Areas in Eastern Chemung County, New York

Science.gov (United States)

Heisig, Paul M.

2015-10-19

The extent, hydrogeologic framework, and potential well yields of valley-fill aquifers within a 151-square-mile area of eastern Chemung County, New York, were investigated, and the upland distribution of till thickness over bedrock was characterized. The hydrogeologic framework of these valleyfill aquifers was interpreted from multiple sources of surficial and subsurface data and an interpretation of the origin of the glacial deposits, particularly during retreat of glacial ice from the region. Potential yields of screened wells are based on the hydrogeologic framework interpretation and existing well-yield data, most of which are from wells finished with open-ended well casing.

N-Glycans on the Rift Valley Fever Virus Envelope Glycoproteins Gn and Gc Redundantly Support Viral Infection via DC-SIGN

Science.gov (United States)

Phoenix, Inaia; Nishiyama, Shoko; Lokugamage, Nandadeva; Hill, Terence E.; Huante, Matthew B.; Slack, Olga A.L.; Carpio, Victor H.; Freiberg, Alexander N.; Ikegami, Tetsuro

2016-01-01

Rift Valley fever is a mosquito-transmitted, zoonotic disease that infects humans and ruminants. Dendritic cell specific intercellular adhesion molecule 3 (ICAM-3) grabbing non-integrin (DC-SIGN) acts as a receptor for members of the phlebovirus genus. The Rift Valley fever virus (RVFV) glycoproteins (Gn/Gc) encode five putative N-glycan sequons (asparagine (N)–any amino acid (X)–serine (S)/threonine (T)) at positions: N438 (Gn), and N794, N829, N1035, and N1077 (Gc). The N-glycosylation profile and significance in viral infection via DC-SIGN have not been elucidated. Gc N-glycosylation was first evaluated by using Gc asparagine (N) to glutamine (Q) mutants. Subsequently, we generated a series of recombinant RVFV MP-12 strain mutants, which encode N-to-Q mutations, and the infectivity of each mutant in Jurkat cells stably expressing DC-SIGN was evaluated. Results showed that Gc N794, N1035, and N1077 were N-glycosylated but N829 was not. Gc N1077 was heterogeneously N-glycosylated. RVFV Gc made two distinct N-glycoforms: “Gc-large” and “Gc-small”, and N1077 was responsible for “Gc-large” band. RVFV showed increased infection of cells expressing DC-SIGN compared to cells lacking DC-SIGN. Infection via DC-SIGN was increased in the presence of either Gn N438 or Gc N1077. Our study showed that N-glycans on the Gc and Gn surface glycoproteins redundantly support RVFV infection via DC-SIGN. PMID:27223297

Rift Valley fever: Real or perceived threat for Zambia?

Directory of Open Access Journals (Sweden)

George Dautu

2012-06-01

Full Text Available Rift Valley fever (RVF in Zambia was first reported in 1974 during an epizootic of cattle and sheep that occurred in parts of Central, Southern and Copperbelt Provinces. In 1990, the disease was documented in nine districts of the provinces of Zambia. In the last two decades, there have been no reports of RVF. This long period without reported clinical disease raises questions as to whether RVF is a current or just a perceived threat. To address this question, World Organisation for Animal Health (OIE disease occurrence data on RVF for the period 2005−2010 in the Southern Africa Development Community (SADC was analysed. From the analysis, it was evident that most countries that share a common border with Zambia had reported at least one occurrence of the disease during the period under review. Due to the absence of natural physical barriers between Zambia and most of her neighbours, informal livestock trade and movements is a ubiquitous reality. Analysis of the rainfall patterns also showed that Zambia received rains sufficient to support a mosquito population large enough for high risk of RVF transmission. The evidence of disease occurrence in nearby countries coupled with animal movement, and environmental risk suggests that RVF is a serious threat to Zambia. In conclusion, the current occurrence of RVF in Zambia is unclear, but there are sufficient indications that the magnitude of the circulating infection is such that capacity building in disease surveillance and courses on recognition of the disease for field staff is recommended. Given the zoonotic potential of RVF, these measures are also a prerequisite for accurate assessment of the disease burden in humans.

Reprint of "Epidemiology of brucellosis, Q Fever and Rift Valley Fever at the human and livestock interface in northern Côte d'Ivoire".

Science.gov (United States)

Kanouté, Youssouf B; Gragnon, Biégo G; Schindler, Christian; Bonfoh, Bassirou; Schelling, Esther

2017-11-01

Northern Côte d'Ivoire is the main livestock breeding zone and has the highest livestock cross-border movements in Côte d'Ivoire. The aim of this study was to provide updated epidemiological data on three neglected zoonotic diseases, namely brucellosis, Q Fever and Rift Valley Fever (RVF). We conducted three-stage cross-sectional cluster surveys in livestock and humans between 2012 and 2014 in a random selection of 63 villages and a sample of 633 cattle, 622 small ruminants and 88 people. We administered questionnaires to capture risk factors and performed serological tests including the Rose Bengal Plate Test (RBPT), Brucella spp. indirect and competitive ELISAs, Coxiella burnetii indirect ELISA and RVF competitive ELISA. The human seroprevalence for Brucella spp. was 5.3%. RBPT-positive small ruminants tested negative by the indirect ELISA. The seroprevalence of Brucella spp. in cattle adjusted for clustering was 4.6%. Cattle aged 5-8 years had higher odds of seropositivity (OR=3.5) than those aged ≤4years. The seropositivity in cattle was associated with having joint hygromas (OR=9), sharing the pastures with small ruminants (OR=5.8) and contact with pastoralist herds (OR=11.3). The seroprevalence of Q Fever was 13.9% in cattle, 9.4% in sheep and 12.4% in goats. The seroprevalence of RVF was 3.9% in cattle, 2.4% in sheep and 0% in goats. Seropositive ewes had greater odds (OR=4.7) of abortion than seronegative ones. In cattle, a shorter distance between the night pens and nearest permanent water bodies was a protective factor (OR=0.1). The study showed that the exposure to the three zoonoses is rather low in northern Côte d'Ivoire. Within a One Health approach, cost-benefit and cost-effectiveness of control measures should be assessed for an integrated control. Copyright © 2017 Elsevier B.V. All rights reserved.

Identification of Rift Valley fever virus nucleocapsid protein-RNA binding inhibitors using a high-throughput screening assay.

Science.gov (United States)

Ellenbecker, Mary; Lanchy, Jean-Marc; Lodmell, J Stephen

2012-09-01

Rift Valley fever virus (RVFV) is an emerging infectious pathogen that causes severe disease in humans and livestock and has the potential for global spread. Currently, there is no proven effective treatment for RVFV infection, and there is no licensed vaccine. Inhibition of RNA binding to the essential viral nucleocapsid (N) protein represents a potential antiviral therapeutic strategy because all of the functions performed by N during infection involve RNA binding. To target this interaction, we developed a fluorescence polarization-based high-throughput drug-screening assay and tested 26 424 chemical compounds for their ability to disrupt an N-RNA complex. From libraries of Food and Drug Administration-approved drugs, druglike molecules, and natural product extracts, we identified several lead compounds that are promising candidates for medicinal chemistry.

Rift Valley fever phlebovirus NSs protein core domain structure suggests molecular basis for nuclear filaments.

Science.gov (United States)

Barski, Michal; Brennan, Benjamin; Miller, Ona K; Potter, Jane A; Vijayakrishnan, Swetha; Bhella, David; Naismith, James H; Elliott, Richard M; Schwarz-Linek, Ulrich

2017-09-15

Rift Valley fever phlebovirus (RVFV) is a clinically and economically important pathogen increasingly likely to cause widespread epidemics. RVFV virulence depends on the interferon antagonist non-structural protein (NSs), which remains poorly characterized. We identified a stable core domain of RVFV NSs (residues 83-248), and solved its crystal structure, a novel all-helical fold organized into highly ordered fibrils. A hallmark of RVFV pathology is NSs filament formation in infected cell nuclei. Recombinant virus encoding the NSs core domain induced intranuclear filaments, suggesting it contains all essential determinants for nuclear translocation and filament formation. Mutations of key crystal fibril interface residues in viruses encoding full-length NSs completely abrogated intranuclear filament formation in infected cells. We propose the fibrillar arrangement of the NSs core domain in crystals reveals the molecular basis of assembly of this key virulence factor in cell nuclei. Our findings have important implications for fundamental understanding of RVFV virulence.

Functional analysis of Rift Valley fever virus NSs encoding a partial truncation.

Science.gov (United States)

Head, Jennifer A; Kalveram, Birte; Ikegami, Tetsuro

2012-01-01

Rift Valley fever virus (RVFV), belongs to genus Phlebovirus of the family Bunyaviridae, causes high rates of abortion and fetal malformation in infected ruminants as well as causing neurological disorders, blindness, or lethal hemorrhagic fever in humans. RVFV is classified as a category A priority pathogen and a select agent in the U.S., and currently there are no therapeutics available for RVF patients. NSs protein, a major virulence factor of RVFV, inhibits host transcription including interferon (IFN)-β mRNA synthesis and promotes degradation of dsRNA-dependent protein kinase (PKR). NSs self-associates at the C-terminus 17 aa., while NSs at aa.210-230 binds to Sin3A-associated protein (SAP30) to inhibit the activation of IFN-β promoter. Thus, we hypothesize that NSs function(s) can be abolished by truncation of specific domains, and co-expression of nonfunctional NSs with intact NSs will result in the attenuation of NSs function by dominant-negative effect. Unexpectedly, we found that RVFV NSs truncated at aa. 6-30, 31-55, 56-80, 81-105, 106-130, 131-155, 156-180, 181-205, 206-230, 231-248 or 249-265 lack functions of IFN-β mRNA synthesis inhibition and degradation of PKR. Truncated NSs were less stable in infected cells, while nuclear localization was inhibited in NSs lacking either of aa.81-105, 106-130, 131-155, 156-180, 181-205, 206-230 or 231-248. Furthermore, none of truncated NSs had exhibited significant dominant-negative functions for NSs-mediated IFN-β suppression or PKR degradation upon co-expression in cells infected with RVFV. We also found that any of truncated NSs except for intact NSs does not interact with RVFV NSs even in the presence of intact C-terminus self-association domain. Our results suggest that conformational integrity of NSs is important for the stability, cellular localization and biological functions of RVFV NSs, and the co-expression of truncated NSs does not exhibit dominant-negative phenotype.

Functional analysis of Rift Valley fever virus NSs encoding a partial truncation.

Directory of Open Access Journals (Sweden)

Jennifer A Head

Full Text Available Rift Valley fever virus (RVFV, belongs to genus Phlebovirus of the family Bunyaviridae, causes high rates of abortion and fetal malformation in infected ruminants as well as causing neurological disorders, blindness, or lethal hemorrhagic fever in humans. RVFV is classified as a category A priority pathogen and a select agent in the U.S., and currently there are no therapeutics available for RVF patients. NSs protein, a major virulence factor of RVFV, inhibits host transcription including interferon (IFN-β mRNA synthesis and promotes degradation of dsRNA-dependent protein kinase (PKR. NSs self-associates at the C-terminus 17 aa., while NSs at aa.210-230 binds to Sin3A-associated protein (SAP30 to inhibit the activation of IFN-β promoter. Thus, we hypothesize that NSs function(s can be abolished by truncation of specific domains, and co-expression of nonfunctional NSs with intact NSs will result in the attenuation of NSs function by dominant-negative effect. Unexpectedly, we found that RVFV NSs truncated at aa. 6-30, 31-55, 56-80, 81-105, 106-130, 131-155, 156-180, 181-205, 206-230, 231-248 or 249-265 lack functions of IFN-β mRNA synthesis inhibition and degradation of PKR. Truncated NSs were less stable in infected cells, while nuclear localization was inhibited in NSs lacking either of aa.81-105, 106-130, 131-155, 156-180, 181-205, 206-230 or 231-248. Furthermore, none of truncated NSs had exhibited significant dominant-negative functions for NSs-mediated IFN-β suppression or PKR degradation upon co-expression in cells infected with RVFV. We also found that any of truncated NSs except for intact NSs does not interact with RVFV NSs even in the presence of intact C-terminus self-association domain. Our results suggest that conformational integrity of NSs is important for the stability, cellular localization and biological functions of RVFV NSs, and the co-expression of truncated NSs does not exhibit dominant-negative phenotype.

Risk factors associated with human Rift Valley fever infection: systematic review and meta-analysis.

Science.gov (United States)

Nicholas, Dennis E; Jacobsen, Kathryn H; Waters, Nigel M

2014-12-01

To identify risk factors for human Rift Valley fever virus (RVFV) infection. A systematic review identified 17 articles reporting on 16 studies examining risk factors for RVFV. Pooled odds ratios (pOR) were calculated for exposures examined in four or more studies. Being male [pOR = 1.4 (1.0, 1.8)], contact with aborted animal tissue [pOR = 3.4 (1.6, 7.3)], birthing an animal [pOR = 3.2 (2.4, 4.2)], skinning an animal [pOR = 2.5 (1.9, 3.2)], slaughtering an animal [pOR = 2.4 (1.4, 4.1)] and drinking raw milk [pOR = 1.8 (1.2, 2.6)] were significantly associated with RVF infection after meta-analysis. Other potential risk factors include sheltering animals in the home and milking an animal, which may both involve contact with animal body fluids. Based on the identified risk factors, use of personal protective equipment and disinfectants by animal handlers may help reduce RVFV transmission during outbreaks. Milk pasteurisation and other possible preventive methods require further investigation. © 2014 John Wiley & Sons Ltd.

Modeling the Impact of Climate Change on the Dynamics of Rift Valley Fever

Directory of Open Access Journals (Sweden)

Saul C. Mpeshe

2014-01-01

Full Text Available A deterministic SEIR model of rift valley fever (RVF with climate change parameters was considered to compute the basic reproduction number ℛ0 and investigate the impact of temperature and precipitation on ℛ0. To study the effect of model parameters to ℛ0, sensitivity and elasticity analysis of ℛ0 were performed. When temperature and precipitation effects are not considered, ℛ0 is more sensitive to the expected number of infected Aedes spp. due to one infected livestock and more elastic to the expected number of infected livestock due to one infected Aedes spp. When climatic data are used, ℛ0 is found to be more sensitive and elastic to the expected number of infected eggs laid by Aedes spp. via transovarial transmission, followed by the expected number of infected livestock due to one infected Aedes spp. and the expected number of infected Aedes spp. due to one infected livestock for both regions Arusha and Dodoma. These results call for attention to parameters regarding incubation period, the adequate contact rate of Aedes spp. and livestock, the infective periods of livestock and Aedes spp., and the vertical transmission in Aedes species.

Modeling the Impact of Climate Change on the Dynamics of Rift Valley Fever

Science.gov (United States)

Mpeshe, Saul C.; Luboobi, Livingstone S.; Nkansah-Gyekye, Yaw

2014-01-01

A deterministic SEIR model of rift valley fever (RVF) with climate change parameters was considered to compute the basic reproduction number ℛ 0 and investigate the impact of temperature and precipitation on ℛ 0. To study the effect of model parameters to ℛ 0, sensitivity and elasticity analysis of ℛ 0 were performed. When temperature and precipitation effects are not considered, ℛ 0 is more sensitive to the expected number of infected Aedes spp. due to one infected livestock and more elastic to the expected number of infected livestock due to one infected Aedes spp. When climatic data are used, ℛ 0 is found to be more sensitive and elastic to the expected number of infected eggs laid by Aedes spp. via transovarial transmission, followed by the expected number of infected livestock due to one infected Aedes spp. and the expected number of infected Aedes spp. due to one infected livestock for both regions Arusha and Dodoma. These results call for attention to parameters regarding incubation period, the adequate contact rate of Aedes spp. and livestock, the infective periods of livestock and Aedes spp., and the vertical transmission in Aedes species. PMID:24795775

Inter-epidemic transmission of Rift Valley fever in livestock in the Kilombero River Valley, Tanzania: a cross-sectional survey.

Directory of Open Access Journals (Sweden)

Robert D Sumaye

Full Text Available BACKGROUND: In recent years, evidence of Rift Valley fever (RVF transmission during inter-epidemic periods in parts of Africa has increasingly been reported. The inter-epidemic transmissions generally pass undetected where there is no surveillance in the livestock or human populations. We studied the presence of and the determinants for inter-epidemic RVF transmission in an area experiencing annual flooding in southern Tanzania. METHODOLOGY: A cross-sectional sero-survey was conducted in randomly selected cattle, sheep and goats in the Kilombero river valley from May to August 2011, approximately four years after the 2006/07 RVF outbreak in Tanzania. The exposure status to RVF virus (RVFV was determined using two commercial ELISA kits, detecting IgM and IgG antibodies in serum. Information about determinants was obtained through structured interviews with herd owners. FINDINGS: An overall seroprevalence of 11.3% (n = 1680 was recorded; 5.5% in animals born after the 2006/07 RVF outbreak and 22.7% in animals present during the outbreak. There was a linear increase in prevalence in the post-epidemic annual cohorts. Nine inhibition-ELISA positive samples were also positive for RVFV IgM antibodies indicating a recent infection. The spatial distribution of seroprevalence exhibited a few hotspots. The sex difference in seroprevalence in animals born after the previous epidemic was not significant (6.1% vs. 4.6% for females and males respectively, p = 0.158 whereas it was significant in animals present during the outbreak (26.0% vs. 7.8% for females and males respectively, p15 km from the flood plain were more likely to have antibodies than those living <5 km (OR 1.92; 95% CI 1.04-3.56. Species, breed, herd composition, grazing practices and altitude were not associated with seropositivity. CONCLUSION: These findings indicate post-epidemic transmission of RVFV in the study area. The linear increase in seroprevalence in the post-epidemic annual cohorts

Identification of suitable areas for the occurrence of Rift Valley fever outbreaks in Spain using a multiple criteria decision framework.

Science.gov (United States)

Sánchez-Vizcaíno, Fernando; Martínez-López, Beatriz; Sánchez-Vizcaíno, José Manuel

2013-07-26

Rift Valley fever (RVF) is a mosquito-borne viral disease that may produce a considerable impact on the economy in affected countries. In the last decades, the geographic distribution of RVF virus has increased including most of the countries in Africa, Arabia Saudi and Yemen. This situation has raised the concerns regarding its potential introduction in the European Union (EU) countries where the high number of susceptible species and competent vectors may contribute to the spread of the disease and challenge its rapid control. Thus, the identification of the areas and time periods with highest suitability for RVF outbreak occurrence would be useful for improving the early detection and rapid response of the disease into free countries. The objective of this study was to identify suitable areas for the occurrence of RVF outbreaks in Spain using a multiple criteria decision making model based on weighted linear combination of factors in geographical information systems (GIS). To the best of the author's knowledge this is the first comprehensive GIS-based framework that provides risk maps for RVF suitability in an EU country. Spanish zones with the highest suitability for RVF were concentrated in the regions of Extremadura, south-western Castile and Leon, eastern Galicia, Asturias, Cantabria, Basque Country, northern-central and southern region of Andalusia and in the Balearic Islands. October and May were the most suitable months for RVF outbreak occurrence. Methods and results presented here may be useful to target risk-based surveillance strategies and to more cost-effectively control potential RVFV incursions into Spain. Copyright © 2013 Elsevier B.V. All rights reserved.

Knowledge, attitudes and practices on Rift Valley fever among agro pastoral communities in Kongwa and Kilombero districts, Tanzania.

Science.gov (United States)

Shabani, Sasita S; Ezekiel, Mangi J; Mohamed, Mohamed; Moshiro, Candida S

2015-08-21

Rift valley fever (RVF) is a re-emerging viral vector-borne disease with rapid global socio-economic impact. A large RVF outbreak occurred in Tanzania in 2007 and affected more than half of the regions with high (47 %) case fatality rate. Little is known about RVF and its dynamics. A cross sectional study was conducted to assess the knowledge, attitudes and practices regarding RVF in Kongwa and Kilombero districts, Tanzania. We conducted a cross sectional survey among a randomly selected sample of individuals in 2011. We administered questionnaires to collect data on demographic characteristics, knowledge on symptoms, mode of transmission, prevention, attitudes and health seeking practices. A total of 463 community members participated in this study. The mean (±SD) age was 39.8 ± 14.4 years and 238 (51.4 %) were female. Majority of respondents had heard of RVF. However, only 8.8 % knew that mosquitoes were transmitting vectors. Male respondents were more likely to have greater knowledge about RVF. A small proportion mentioned clinical signs and symptoms of RVF in animals while 73.7 % mentioned unhealthy practices related to handling and consumption of dead animals. Thorough boiling of milk and cooking of meat were commonly mentioned as preventive measures for RVF. Majority (74.6 %) sought care for febrile illness at health facilities. Few (24.3 %) reported the use of protective gears to handle dead/sick animal while 15.5 % were consuming dead animals. Our study highlights the need to address the limited knowledge about RVF and promoting appropriate and timely health seeking practices. Rift valley fever outbreaks can be effectively managed with collaborative efforts of lay and professional communities with a shared perception that it poses a serious threat to public and animal health. The fact that this study was conducted in "high risk transmission areas" warrants further inquiry in other geographic regions with relatively low risk of RVF.

Data-driven modeling to assess receptivity for Rift Valley Fever virus.

Directory of Open Access Journals (Sweden)

Christopher M Barker

2013-11-01

Full Text Available Rift Valley Fever virus (RVFV is an enzootic virus that causes extensive morbidity and mortality in domestic ruminants in Africa, and it has shown the potential to invade other areas such as the Arabian Peninsula. Here, we develop methods for linking mathematical models to real-world data that could be used for continent-scale risk assessment given adequate data on local host and vector populations. We have applied the methods to a well-studied agricultural region of California with [Formula: see text]1 million dairy cattle, abundant and competent mosquito vectors, and a permissive climate that has enabled consistent transmission of West Nile virus and historically other arboviruses. Our results suggest that RVFV outbreaks could occur from February-November, but would progress slowly during winter-early spring or early fall and be limited spatially to areas with early increases in vector abundance. Risk was greatest in summer, when the areas at risk broadened to include most of the dairy farms in the study region, indicating the potential for considerable economic losses if an introduction were to occur. To assess the threat that RVFV poses to North America, including what-if scenarios for introduction and control strategies, models such as this one should be an integral part of the process; however, modeling must be paralleled by efforts to address the numerous remaining gaps in data and knowledge for this system.

Dual functions of Rift Valley fever virus NSs protein: inhibition of host mRNA transcription and post-transcriptional downregulation of protein kinase PKR.

Science.gov (United States)

Ikegami, Tetsuro; Narayanan, Krishna; Won, Sungyong; Kamitani, Wataru; Peters, C J; Makino, Shinji

2009-09-01

Rift Valley fever virus (RVFV), which belongs to the genus Phlebovirus, family Bunyaviridae, is a negative-stranded RNA virus carrying a single-stranded, tripartite RNA genome. RVFV is an important zoonotic pathogen transmitted by mosquitoes and causes large outbreaks among ruminants and humans in Africa and the Arabian Peninsula. Human patients develop an acute febrile illness, followed by a fatal hemorrhagic fever, encephalitis, or ocular diseases. A viral nonstructural protein, NSs, is a major viral virulence factor. Past studies showed that NSs suppresses the transcription of host mRNAs, including interferon-beta mRNAs. Here we demonstrated that the NSs protein induced post-transcriptional downregulation of dsRNA-dependent protein kinase (PKR), to prevent phosphorylation of eIF2alpha and promoted viral translation in infected cells. These two biological activities of the NSs most probably have a synergistic effect in suppressing host innate immune functions and facilitate efficient viral replication in infected mammalian hosts.

Clinical and Haematological Manifestations of Typhoid Fever in Children in Eastern Turkey.

Science.gov (United States)

Akbayram, S; Parlak, M; Dogan, M; Karasin, G; Akbayram, H T; Karaman, K

2016-01-12

Typhoid fever can involve various organs, leading to a wide range of presentations: from uncomplicated to complicated typhoid fever. The haematological changes are common in typhoid fever and include anaemia, leucopaenia, thrombocytopaenia and bleeding diathesis. This study was undertaken in order to determine the clinical and haematological presentation of typhoid fever in children. In this study, records of children and adolescents with typhoid fever aged under or equal to 16 years, admitted to Yuzuncu Yil University Hospital between 2010 and 2014, were analysed retrospectively. The cases (56%) were admitted to our hospital in July and October. Major symptoms of patients were abdominal pain (24%), arthralgia (21%) and fever (11%). In our study, decreased mean platelet volume (31%), eosinopaenia 20%), abnormal platelet count (19%), anaemia (16%), leucocytosis (16%) and eosinophilia (12%) were the most common haematological findings in the children. Typhoid fever is predominant in children at school age with a slight male predominance. Decreased mean platelet volume and abdominal pain might be useful as early diagnostic clues.

Wolbachia Effects on Rift Valley Virus Infection in Culex tarsalis Mosquitoes

Science.gov (United States)

2017-04-25

Wolbachia density in mosquitoes. 109" 110" Materials and Methods 111" Ethics statement 112" TR-17-113 Mosquitoes were maintained on commercially available...fever virus. 379" Vet Med Today. 2009; 883–893. 380" 29. Wilson M. Rift Valley fever virus ecology and the epidemiology of disease emergence. 381

Rift Valley fever: current challenges and future prospects

Directory of Open Access Journals (Sweden)

Himeidan YE

2016-03-01

Full Text Available Yousif E Himeidan Vector Control Unit, Africa Technical Research Centre, Vector Health International, Arusha, Tanzania Abstract: Rift Valley fever (RVF is a zoonotic, mosquito-borne viral disease that affects human health and causes significant losses in the livestock industry. Recent outbreaks have led to severe human infections with high mortality rates. There are many challenges to applying effective preventive and control measures, including weak infrastructure of health facilities, lack of capacity and support systems for field logistics and communication, access to global expert organizations, and insufficient information on the epidemiological and reservoir status of the RVF virus. The health systems in East African countries are underdeveloped, with gaps in adaptability to new, more accurate and rapid techniques, and well-trained staff that affect their capacity to monitor and evaluate the disease. Surveillance and response systems are inadequate in providing accurate information in a timely manner for decision making to deal with the scope of interrupting the disease transmission by applying mass animal vaccination, and other preventive measures at the early stage of an outbreak. The historical vaccines are unsuitable for use in newborn and gestating livestock, and the recent ones require a booster and annual revaccination. Future live-attenuated RVF vaccines should possess lower safety concerns regardless of the physiologic state of the animal, and provide rapid and long-term immunity after a single dose of vaccination. In the absence of an effective vaccination program, prevention and control measures must be immediately undertaken after an alert is generated. These measures include enforcing and adapting standard protocols for animal trade and movement, extensive vector control, safe disposal of infected animals, and modification of human–animal contact behavior. Directing control efforts on farmers and workers who deal with

Identification of potential vectors of and detection of antibodies against Rift Valley fever virus in livestock during interepizootic periods.

Science.gov (United States)

Rostal, Melinda K; Evans, Alina L; Sang, Rosemary; Gikundi, Solomon; Wakhule, Lilian; Munyua, Peninah; Macharia, Joseph; Feikin, Daniel R; Breiman, Robert F; Njenga, M Kariuki

2010-05-01

To evaluate the prevalence of Rift Valley fever virus (RVFV) antibodies in livestock and presence of competent mosquito vectors of RVFV during an interepizootic period (IEP) in Kenya. 208 sheep and 84 goats ranging in age from 4 months to 15 years, from 2 breeding herds. Blood specimens were collected from the sheep and goats during the 1999-2006 IEP in Rift Valley Province, and serum was harvested. Serum specimens were tested for IgG and IgM antibodies against RVFV by use of an ELISA. In addition, 7,134 mosquitoes were trapped in Naivasha, Nairobi, and Northeastern Province, and speciation was performed. No animals were seropositive for IgM against RVFV. Of the animals born after the 1997-1998 epizootic, 18% (34/188) of sheep were seropositive for IgG against RVFV, compared with 3% (2/75) of goats. Seventy percent (8,144/11,678) of the mosquitoes collected were of the Culex subgenera; 18% (2,102/11,678) were Aedes spp. Detection of IgG in the sera of sheep and goats born after the 1997-1998 epizootic and before the 2006 epizootic indicated that virus activity existed during the IEP. Detection of Aedes mosquitoes, which are competent vectors of RVFV, suggested that a cryptic vector-to-vertebrate cycle may exist during IEPs.

An unexpected recurrent transmission of Rift Valley fever virus in cattle in a temperate and mountainous area of Madagascar.

Directory of Open Access Journals (Sweden)

Veronique Chevalier

2011-12-01

Full Text Available Rift Valley fever is an acute, zoonotic viral disease of domestic ruminants, caused by a phlebovirus (Bunyaviridae family. A large outbreak occurred in Madagascar in 2008-2009. The goal of the present study was to evaluate the point prevalence of antibodies against Rift Valley Fever Virus (RVFV in cattle in the Anjozorobe district, located in the wet and temperate highland region of Madagascar and yet heavily affected by the disease, and analyse environmental and trade factors potentially linked to RVFV transmission. A serological study was performed in 2009 in 894 bovines. For each bovine, the following variables were recorded: age, location of the night pen, minimum distance from the pen to the nearest water point and the forest, nearest water point type, and herd replacement practices. The serological data were analyzed using a generalized linear mixed model. The overall anti-RVFV IgG seroprevalence rate was 28% [CI95% 25-31]. Age was statistically linked to prevalence (p = 10(-4, being consistent with a recurrent RVFV circulation. Distance from the night pen to the nearest water point was a protective factor (p = 5.10(-3, which would be compatible with a substantial part of the virus transmission being carried out by nocturnal mosquito vectors. However, water point type did not influence the risk of infection: several mosquito species are probably involved. Cattle belonging to owners who purchase animals to renew the herd were significantly more likely to have seroconverted than others (p = 0.04: cattle trade may contribute to the introduction of the virus in this area. The minimum distance of the night pen to the forest was not linked to the prevalence. This is the first evidence of a recurrent transmission of RVFV in such an ecosystem that associates a wet, temperate climate, high altitude, paddy fields, and vicinity to a dense rain forest. Persistence mechanisms need to be further investigated.

Climate teleconnections and recent patterns of human and animal disease outbreaks.

Directory of Open Access Journals (Sweden)

Assaf Anyamba

2012-01-01

Full Text Available Recent clusters of outbreaks of mosquito-borne diseases (Rift Valley fever and chikungunya in Africa and parts of the Indian Ocean islands illustrate how interannual climate variability influences the changing risk patterns of disease outbreaks. Although Rift Valley fever outbreaks have been known to follow periods of above-normal rainfall, the timing of the outbreak events has largely been unknown. Similarly, there is inadequate knowledge on climate drivers of chikungunya outbreaks. We analyze a variety of climate and satellite-derived vegetation measurements to explain the coupling between patterns of climate variability and disease outbreaks of Rift Valley fever and chikungunya.We derived a teleconnections map by correlating long-term monthly global precipitation data with the NINO3.4 sea surface temperature (SST anomaly index. This map identifies regional hot-spots where rainfall variability may have an influence on the ecology of vector borne disease. Among the regions are Eastern and Southern Africa where outbreaks of chikungunya and Rift Valley fever occurred 2004-2009. Chikungunya and Rift Valley fever case locations were mapped to corresponding climate data anomalies to understand associations between specific anomaly patterns in ecological and climate variables and disease outbreak patterns through space and time. From these maps we explored associations among Rift Valley fever disease occurrence locations and cumulative rainfall and vegetation index anomalies. We illustrated the time lag between the driving climate conditions and the timing of the first case of Rift Valley fever. Results showed that reported outbreaks of Rift Valley fever occurred after ∼3-4 months of sustained above-normal rainfall and associated green-up in vegetation, conditions ideal for Rift Valley fever mosquito vectors. For chikungunya we explored associations among surface air temperature, precipitation anomalies, and chikungunya outbreak locations. We found

Distinct virulence of Rift Valley fever phlebovirus strains from different genetic lineages in a mouse model.

Directory of Open Access Journals (Sweden)

Tetsuro Ikegami

Full Text Available Rift Valley fever phlebovirus (RVFV causes high rates of abortions and fetal malformations in ruminants, and hemorrhagic fever, encephalitis, or blindness in humans. Viral transmission occurs via mosquito vectors in endemic areas, which necessitates regular vaccination of susceptible livestock animals to prevent the RVF outbreaks. Although ZH501 strain has been used as a challenge strain for past vaccine efficacy studies, further characterization of other RVFV strains is important to optimize ruminant and nonhuman primate RVFV challenge models. This study aimed to characterize the virulence of wild-type RVFV strains belonging to different genetic lineages in outbred CD1 mice. Mice were intraperitoneally infected with 1x103 PFU of wild-type ZH501, Kenya 9800523, Kenya 90058, Saudi Arabia 200010911, OS1, OS7, SA75, Entebbe, or SA51 strains. Among them, mice infected with SA51, Entebbe, or OS7 strain showed rapid dissemination of virus in livers and peracute necrotic hepatitis at 2-3 dpi. Recombinant SA51 (rSA51 and Zinga (rZinga strains were recovered by reverse genetics, and their virulence was also tested in CD1 mice. The rSA51 strain reproduced peracute RVF disease in mice, whereas the rZinga strain showed a similar virulence with that of rZH501 strain. This study showed that RVFV strains in different genetic lineages display distinct virulence in outbred mice. Importantly, since wild-type RVFV strains contain defective-interfering RNA or various genetic subpopulations during passage from original viral isolations, recombinant RVFV strains generated by reverse genetics will be better suitable for reproducible challenge studies for vaccine development as well as pathological studies.

Spatial, seasonal and climatic predictive models of Rift Valley fever disease across Africa.

Science.gov (United States)

Redding, David W; Tiedt, Sonia; Lo Iacono, Gianni; Bett, Bernard; Jones, Kate E

2017-07-19

Understanding the emergence and subsequent spread of human infectious diseases is a critical global challenge, especially for high-impact zoonotic and vector-borne diseases. Global climate and land-use change are likely to alter host and vector distributions, but understanding the impact of these changes on the burden of infectious diseases is difficult. Here, we use a Bayesian spatial model to investigate environmental drivers of one of the most important diseases in Africa, Rift Valley fever (RVF). The model uses a hierarchical approach to determine how environmental drivers vary both spatially and seasonally, and incorporates the effects of key climatic oscillations, to produce a continental risk map of RVF in livestock (as a proxy for human RVF risk). We find RVF risk has a distinct seasonal spatial pattern influenced by climatic variation, with the majority of cases occurring in South Africa and Kenya in the first half of an El Niño year. Irrigation, rainfall and human population density were the main drivers of RVF cases, independent of seasonal, climatic or spatial variation. By accounting more subtly for the patterns in RVF data, we better determine the importance of underlying environmental drivers, and also make space- and time-sensitive predictions to better direct future surveillance resources.This article is part of the themed issue 'One Health for a changing world: zoonoses, ecosystems and human well-being'. © 2017 The Authors.

Development of a novel, single-cycle replicable rift valley Fever vaccine.

Directory of Open Access Journals (Sweden)

Shin Murakami

2014-03-01

Full Text Available Rift Valley fever virus (RVFV (genus Phlebovirus, family Bunyaviridae is an arbovirus that causes severe disease in humans and livestock in sub-Saharan African countries. Although the MP-12 strain of RVFV is a live attenuated vaccine candidate, neuroinvasiveness and neurovirulence of MP-12 in mice may be a concern when vaccinating certain individuals, especially those that are immunocompromised. We have developed a novel, single-cycle replicable MP-12 (scMP-12, which carries an L RNA, M RNA mutant encoding a mutant envelope protein lacking an endoplasmic reticulum retrieval signal and defective for membrane fusion function, and S RNA encoding N protein and green fluorescent protein. The scMP-12 underwent efficient amplification, then formed plaques and retained the introduced mutation after serial passages in a cell line stably expressing viral envelope proteins. However, inoculation of the scMP-12 into naïve cells resulted in a single round of viral replication, and production of low levels of noninfectious virus-like particles. Intracranial inoculation of scMP-12 into suckling mice did not cause clinical signs or death, a finding which demonstrated that the scMP-12 lacked neurovirulence. Mice immunized with a single dose of scMP-12 produced neutralizing antibodies, whose titers were higher than in mice immunized with replicon particles carrying L RNA and S RNA encoding N protein and green fluorescent protein. Moreover, 90% of the scMP-12-immunized mice were protected from wild-type RVFV challenge by efficiently suppressing viremia and replication of the challenge virus in the liver and the spleen. These data demonstrated that scMP-12 is a safe and immunogenic RVFV vaccine candidate.

Rift Valley fever virus infections in Egyptian cattle and their prevention.

Science.gov (United States)

Mroz, C; Gwida, M; El-Ashker, M; Ziegler, U; Homeier-Bachmann, T; Eiden, M; Groschup, M H

2017-12-01

Rift Valley fever virus (RVFV) causes consistently severe outbreaks with high public health impacts and economic losses in livestock in many African countries and has also been introduced to Saudi Arabia and Yemen. Egypt with its four large outbreaks in the last 40 years represents the northernmost endemic area of RVFV. The purpose of this study was to provide an insight into the current anti-RVFV antibody status in immunized as well as non-immunized dairy cattle from the Nile Delta of Egypt. During 2013-2015, a total of 4,167 dairy cattle from four governorates including Dakahlia, Damietta, Gharbia and Port Said were investigated. All cattle were born after 2007 and therewith after the last reported Egyptian RVFV outbreak in 2003. The samples derived from vaccinated animals from 26 different dairy farms as well as non-immunized cattle from 27 different smallholding flocks. All samples were examined following a three-part analysis including a commercially available competition ELISA, an in-house immunofluorescence assay and a virus neutralization test. Additionally, a subset of samples was analysed for acute infections using IgM ELISA and real-time reverse transcriptase PCR. The results indicated that the RVFV is still circulating in Egypt as about 10% of the non-immunized animals exhibited RVFV-specific antibodies. Surprisingly, the antibody prevalence in immunized animals was not significantly higher than that in non-vaccinated animals which points out the need for further evaluation of the vaccination programme. Due to the substantial role of livestock in the amplification and transmission of RVFV, further recurrent monitoring of the antibody prevalence in susceptible species is highly warranted. © 2017 Blackwell Verlag GmbH.

The Luangwa Valley, Zambia: flyway and stopover site for White ...

African Journals Online (AJOL)

Analyses of satellite telemetry data of White Storks Ciconia ciconia from the eastern populations at their stopover sites and staging areas document the importance of the Luangwa Valley, eastern Zambia, as a migration corridor bridging eastern and southern Africa. Twice each year from November to April, up to 100 000 ...

Relationship of climate, geography, and geology to the incidence of Rift Valley fever in Kenya during the 2006-2007 outbreak.

Science.gov (United States)

Hightower, Allen; Kinkade, Carl; Nguku, Patrick M; Anyangu, Amwayi; Mutonga, David; Omolo, Jared; Njenga, M Kariuki; Feikin, Daniel R; Schnabel, David; Ombok, Maurice; Breiman, Robert F

2012-02-01

We estimated Rift Valley fever (RVF) incidence as a function of geological, geographical, and climatological factors during the 2006-2007 RVF epidemic in Kenya. Location information was obtained for 214 of 340 (63%) confirmed and probable RVF cases that occurred during an outbreak from November 1, 2006 to February 28, 2007. Locations with subtypes of solonetz, calcisols, solonchaks, and planosols soil types were highly associated with RVF occurrence during the outbreak period. Increased rainfall and higher greenness measures before the outbreak were associated with increased risk. RVF was more likely to occur on plains, in densely bushed areas, at lower elevations, and in the Somalia acacia ecological zone. Cases occurred in three spatial temporal clusters that differed by the date of associated rainfall, soil type, and land usage.

Emerging vector-borne diseases in dromedaries in Tunisia: West Nile, bluetongue, epizootic haemorrhagic disease and Rift Valley fever

Directory of Open Access Journals (Sweden)

Thameur B. Hassine

2017-03-01

Full Text Available A total of 118 sera were collected during 2016 from two groups of dromedaries from Kebili and Medenine governorates in the south of Tunisia. The aim of this study was to provide the first serological investigation of four emerging vector-borne diseases in two groups of dromedaries in Tunisia. Sera were tested by ELISA and serum neutralisation test to identify West Nile virus (WNV, bluetongue virus (BTV, epizootic haemorrhagic disease virus (EHDV and Rift Valley fever virus (RVFV. In the first group, the seroprevalence for BTV was 4.6%, while in the second group, it was 25.8% for WNV and 9.7% for BTV. Only serotype 1 was detected for BTV in the two groups. No evidence for circulation of RVF and EHD viruses was revealed. Results indicated that dromedaries can be infected with BTV and WNV, suggesting that this species might play a significant role in the epizootiology of these viral diseases in Tunisia and neighbouring countries.

Emerging vector-borne diseases in dromedaries in Tunisia: West Nile, bluetongue, epizootic haemorrhagic disease and Rift Valley fever.

Science.gov (United States)

Hassine, Thameur B; Amdouni, Jihane; Monaco, Federica; Savini, Giovanni; Sghaier, Soufien; Selimen, Imed B; Chandoul, Walid; Hamida, Khaled B; Hammami, Salah

2017-03-31

A total of 118 sera were collected during 2016 from two groups of dromedaries from Kebili and Medenine governorates in the south of Tunisia. The aim of this study was to provide the first serological investigation of four emerging vector-borne diseases in two groups of dromedaries in Tunisia. Sera were tested by ELISA and serum neutralisation test to identify West Nile virus (WNV), bluetongue virus (BTV), epizootic haemorrhagic disease virus (EHDV) and Rift Valley fever virus (RVFV). In the first group, the seroprevalence for BTV was 4.6%, while in the second group, it was 25.8% for WNV and 9.7% for BTV. Only serotype 1 was detected for BTV in the two groups. No evidence for circulation of RVF and EHD viruses was revealed. Results indicated that dromedaries can be infected with BTV and WNV, suggesting that this species might play a significant role in the epizootiology of these viral diseases in Tunisia and neighbouring countries.

Planning for Rift Valley fever virus: use of geographical information systems to estimate the human health threat of white-tailed deer (Odocoileus virginianus-related transmission

Directory of Open Access Journals (Sweden)

Sravan Kakani

2010-11-01

Full Text Available Rift Valley fever (RVF virus is a mosquito-borne phlebovirus of the Bunyaviridae family that causes frequent outbreaks of severe animal and human disease in sub-Saharan Africa, Egypt and the Arabian Peninsula. Based on its many known competent vectors, its potential for transmission via aerosolization, and its progressive spread from East Africa to neighbouring regions, RVF is considered a high-priority, emerging health threat for humans, livestock and wildlife in all parts of the world. Introduction of West Nile virus to North America has shown the potential for “exotic” viral pathogens to become embedded in local ecological systems. While RVF is known to infect and amplify within domestic livestock, such as taurine cattle, sheep and goats, if RVF virus is accidentally or intentionally introduced into North America, an important unknown factor will be the role of local wildlife in the maintenance or propagation of virus transmission. We examined the potential impact of RVF transmission via white-tailed deer (Odocoileus virginianus in a typical north-eastern United States urban-suburban landscape, where livestock are rare but where these potentially susceptible, ungulate wildlife are highly abundant. Model results, based on overlap of mosquito, human and projected deer densities, indicate that a significant proportion (497/1186 km2, i.e. 42% of the urban and peri-urban landscape could be affected by RVF transmission during the late summer months. Deer population losses, either by intervention for herd reduction or by RVF-related mortality, would substantially reduce these likely transmission zones to 53.1 km2, i.e. by 89%.

First recorded outbreak of yellow fever in Kenya, 1992-1993. II. Entomologic investigations.

Science.gov (United States)

Reiter, P; Cordellier, R; Ouma, J O; Cropp, C B; Savage, H M; Sanders, E J; Marfin, A A; Tukei, P M; Agata, N N; Gitau, L G; Rapuoda, B A; Gubler, D J

1998-10-01

The first recorded outbreak of yellow fever in Kenya occurred from mid-1992 through March 1993 in the south Kerio Valley, Rift Valley Province. We conducted entomologic studies in February-March 1993 to identify the likely vectors and determine the potential for transmission in the surrounding rural and urban areas. Mosquitoes were collected by landing capture and processed for virus isolation. Container surveys were conducted around human habitation. Transmission was mainly in woodland of varying density, at altitudes of 1,300-1,800 m. The abundance of Aedes africanus in this biotope, and two isolations of virus from pools of this species, suggest that it was the principal vector in the main period of the outbreak. A third isolate was made from a pool of Ae. keniensis, a little-known species that was collected in the same biotope. Other known yellow fever vectors that were collected in the arid parts of the valley may have been involved at an earlier stage of the epidemic. Vervet monkeys and baboons were present in the outbreak area. Peridomestic mosquito species were absent but abundant at urban sites outside the outbreak area. The entomologic and epidemiologic evidence indicate that this was a sylvatic outbreak in which human cases were directly linked to the epizootic and were independent of other human cases. The region of the Kerio Valley is probably subject to recurrent wandering epizootics of yellow fever, although previous episodes of scattered human infection have gone unrecorded. The risk that the disease could emerge as an urban problem in Kenya should not be ignored.

Pathogenic effects of Rift Valley fever virus NSs gene are alleviated in cultured cells by expressed antiviral short hairpin RNAs.

Science.gov (United States)

Scott, Tristan; Paweska, Janusz T; Arbuthnot, Patrick; Weinberg, Marc S

2012-01-01

Rift Valley fever virus (RVFV), a member of the Bunyaviridae family, may cause severe hepatitis, encephalitis and haemorrhagic fever in humans. There are currently no available licensed vaccines or therapies to treat the viral infection in humans. RNA interference (RNAi)-based viral gene silencing offers a promising approach to inhibiting replication of this highly pathogenic virus. The small (S) segment of the RVFV tripartite genome carries the genetic determinates for pathogenicity during infection. This segment encodes the non-structural S (NSs) and essential nucleocapsid (N) genes. To advance RNAi-based inhibition of RVFV replication, we designed several Pol III short hairpin RNA (shRNA) expression cassettes against the NSs and N genes, including a multimerized plasmid vector that included four shRNA expression cassettes. Effective target silencing was demonstrated using full- and partial-length target reporter assays, and confirmed by western blot analysis of exogenous N and NSs expression. Small RNA northern blots showed detectable RNAi guide strand formation from single and multimerized shRNA constructs. Using a cell culture model of RVFV replication, shRNAs targeting the N gene decreased intracellular nucleocapsid protein concentration and viral replication. The shRNAs directed against the NSs gene reduced NSs protein concentrations and alleviated NSs-mediated cytotoxicity, which may be caused by host transcription suppression. These data are the first demonstration that RNAi activators have a potential therapeutic benefit for countering RVFV infection.

Safety and immunogenicity of Onderstepoort Biological Products’ Rift Valley fever Clone 13 vaccine in sheep and goats under field conditions in Senegal

Directory of Open Access Journals (Sweden)

Modou M. Lo

2015-05-01

Full Text Available This blinded field safety study was conducted in Senegal to assess safety and immunogenicity of administration of the registered dose of Rift Valley fever virus (RVFV Clone 13 vaccine (Onderstepoort Biological Products to sheep and goats of West African breeds under natural conditions. A total of 267 small ruminants (220 sheep, 47 goats were included; half received RVFV Clone 13 vaccine at the recommended dose and half received the diluent (as placebo only. The study was performed on three commercial farms in the northern and eastern region of Senegal in accordance with veterinary good clinical practices. The animals were observed daily for 3 days after vaccination, and then weekly for 1 year. In both sheep and goats vaccinated against RVFV seroconversion rates above 70% were recorded. No seroconversion related to RVFV was observed in placebo-treated animals. No statistically significant differences were determined between placebo and vaccinated groups for mean rectal temperatures for the first 3 days after administration (p > 0.05. No abnormal clinical signs related to treatment were noted, and only one slight injection site reaction was observed in one vaccinated animal for 2 days after vaccination. Out of 176 births assessed over 1 year (93 from the vaccinated group, 83 from the placebo group, 9 were abnormal in the placebo group and 3 in the vaccinated group (p > 0.05. The frequency of adverse events was similar in the placebo and vaccinated groups. RVFV Clone 13 vaccine administered according to the manufacturer’s instructions was safe and well tolerated in West African breeds of sheep and goats, including animals of approximately 6 months of age and pregnant females, under field conditions in Senegal. Antibody levels persisted up to 1 year after vaccination.

Rift Valley fever virus NSs protein promotes post-transcriptional downregulation of protein kinase PKR and inhibits eIF2alpha phosphorylation.

Science.gov (United States)

Ikegami, Tetsuro; Narayanan, Krishna; Won, Sungyong; Kamitani, Wataru; Peters, C J; Makino, Shinji

2009-02-01

Rift Valley fever virus (RVFV) (genus Phlebovirus, family Bunyaviridae) is a negative-stranded RNA virus with a tripartite genome. RVFV is transmitted by mosquitoes and causes fever and severe hemorrhagic illness among humans, and fever and high rates of abortions in livestock. A nonstructural RVFV NSs protein inhibits the transcription of host mRNAs, including interferon-beta mRNA, and is a major virulence factor. The present study explored a novel function of the RVFV NSs protein by testing the replication of RVFV lacking the NSs gene in the presence of actinomycin D (ActD) or alpha-amanitin, both of which served as a surrogate of the host mRNA synthesis suppression function of the NSs. In the presence of the host-transcriptional inhibitors, the replication of RVFV lacking the NSs protein, but not that carrying NSs, induced double-stranded RNA-dependent protein kinase (PKR)-mediated eukaryotic initiation factor (eIF)2alpha phosphorylation, leading to the suppression of host and viral protein translation. RVFV NSs promoted post-transcriptional downregulation of PKR early in the course of the infection and suppressed the phosphorylated eIF2alpha accumulation. These data suggested that a combination of RVFV replication and NSs-induced host transcriptional suppression induces PKR-mediated eIF2alpha phosphorylation, while the NSs facilitates efficient viral translation by downregulating PKR and inhibiting PKR-mediated eIF2alpha phosphorylation. Thus, the two distinct functions of the NSs, i.e., the suppression of host transcription, including that of type I interferon mRNAs, and the downregulation of PKR, work together to prevent host innate antiviral functions, allowing efficient replication and survival of RVFV in infected mammalian hosts.

Fundus Findings in Dengue Fever: A Case Report

Directory of Open Access Journals (Sweden)

Berna Şahan

2015-10-01

Full Text Available Dengue fever is a flavivirus infection transmitted through infected mosquitoes, and is endemic in Southeast Asia, Central and South America, the Pacific, Africa and the Eastern Mediterranean region. A 41-year-old male patient had visual impairment after travelling to Thailand, which is one of the endemic areas. Cotton wool spots were observed on fundus examination. Fundus fluorescein angiography showed minimal vascular leakage from areas near the cotton wool spots and dot hemorrhages in the macula. Dengue fever should be considered in patients with visual complaints who traveled to endemic areas of dengue fever. (Turk J Ophthalmol 2015; 45: 223-225

Potential for North American mosquitoes (Diptera: Culicidae) to transmit rift valley fever virus.

Science.gov (United States)

Turell, Michael J; Wilson, William C; Bennett, Kristine E

2010-09-01

To determine which arthropods should be targeted for control should Rift Valley fever virus (RVFV) be detected in North America, we evaluated Culex erraticus (Dyar and Knab), Culex erythrothorax Dyar, Culex nigripalpus Theobald, Culex pipiens L., Culex quinquefasciatus Say, Culex tarsalis Coquillett, Aedes dorsalis (Wiedemann), Aedes vexans (Meigen), Anopheles quadrimaculatus Say, and Culicoides sonorensis Wirth and Jones from the western, midwestern, and southern United States for their ability to transmit RVFV. Female mosquitoes were allowed to feed on adult hamsters inoculated with RVFV, after which engorged mosquitoes were incubated for 7-21 d at 260C, then allowed to refeed on susceptible hamsters, and tested to determine infection, dissemination, and transmission rates. Other specimens were inoculated intrathoracically, held for 7 d, and then allowed to feed on a susceptible hamster to check for a salivary gland barrier. When exposed to hamsters with viremias > or =10(8.8) plaque-forming units/ml blood, Cx. tarsalis transmitted RVFV efficiently (infection rate = 93%, dissemination rate = 56%, and estimated transmission rate = 52%). In contrast, when exposed to the same virus dose, none of the other species tested transmitted RVFV efficiently. Estimated transmission rates for Cx. erythrothorax, Cx. pipiens, Cx. erraticus, and Ae. dorsalis were 10, 8, 4, and 2%, respectively, and for the remaining species were feeding preference, longevity, and foraging behavior should be considered when determining the potential role that these species could play in RVFV transmission.

A fusion-inhibiting peptide against Rift Valley fever virus inhibits multiple, diverse viruses.

Directory of Open Access Journals (Sweden)

Jeffrey W Koehler

Full Text Available For enveloped viruses, fusion of the viral envelope with a cellular membrane is critical for a productive infection to occur. This fusion process is mediated by at least three classes of fusion proteins (Class I, II, and III based on the protein sequence and structure. For Rift Valley fever virus (RVFV, the glycoprotein Gc (Class II fusion protein mediates this fusion event following entry into the endocytic pathway, allowing the viral genome access to the cell cytoplasm. Here, we show that peptides analogous to the RVFV Gc stem region inhibited RVFV infectivity in cell culture by inhibiting the fusion process. Further, we show that infectivity can be inhibited for diverse, unrelated RNA viruses that have Class I (Ebola virus, Class II (Andes virus, or Class III (vesicular stomatitis virus fusion proteins using this single peptide. Our findings are consistent with an inhibition mechanism similar to that proposed for stem peptide fusion inhibitors of dengue virus in which the RVFV inhibitory peptide first binds to both the virion and cell membranes, allowing it to traffic with the virus into the endocytic pathway. Upon acidification and rearrangement of Gc, the peptide is then able to specifically bind to Gc and prevent fusion of the viral and endocytic membranes, thus inhibiting viral infection. These results could provide novel insights into conserved features among the three classes of viral fusion proteins and offer direction for the future development of broadly active fusion inhibitors.

Katayama fever ID scuba divers

African Journals Online (AJOL)

1991-03-02

Mar 2, 1991 ... A. C. EVANS, D. J. MARTIN, B. D. GINSBURG. Summary. Katayama fever or acute schistosomiasis probably occurs more commonly than is recorded. Interviews with a 3-man scuba diving team who had had contact with a large dam in an·endemic area of the eastern Transvaal Lowveld at the same time ...

Burrowing Owl - Palo Verde Valley [ds197

Data.gov (United States)

California Natural Resource Agency — These burrowing owl observations were collected during the spring and early summer of 1976 in the Palo Verde Valley, eastern Riverside County, California. This is an...

Identification of Wild Boar-Habitat Epidemiologic Cycle in African Swine Fever Epizootic.

Science.gov (United States)

Chenais, Erika; Ståhl, Karl; Guberti, Vittorio; Depner, Klaus

2018-04-01

The African swine fever epizootic in central and eastern European Union member states has a newly identified component involving virus transmission by wild boar and virus survival in the environment. Insights led to an update of the 3 accepted African swine fever transmission models to include a fourth cycle: wild boar-habitat.

HEMORRHAGIC-FEVER VIRUS-INFECTIONS IN AN ISOLATED RAIN-FOREST AREA OF CENTRAL LIBERIA - LIMITATIONS OF THE INDIRECT IMMUNOFLUORESCENCE SLIDE TEST FOR ANTIBODY SCREENING IN AFRICA

NARCIS (Netherlands)

van der Waals, F. W.; Pomeroy, K. L.; Goudsmit, J.; Asher, D. M.; Gajdusek, D. C.

1986-01-01

Serum samples from 119 healthy individuals and 106 epilepsy patients inhabiting Grand Bassa County, Liberia, were tested for antibodies to hemorrhagic fever viruses (HFV) by indirect immunofluorescence. E6 Vero cells infected with Lassa fever virus (LAS), Rift Valley Fever virus (RVF), Congo

NSs Virulence Factor of Rift Valley Fever Virus Engages the F-Box Proteins FBXW11 and β-TRCP1 To Degrade the Antiviral Protein Kinase PKR.

Science.gov (United States)

Kainulainen, Markus; Lau, Simone; Samuel, Charles E; Hornung, Veit; Weber, Friedemann

2016-07-01

Rift Valley fever virus (RVFV, family Bunyaviridae, genus Phlebovirus) is a relevant pathogen of both humans and livestock in Africa. The nonstructural protein NSs is a major virulence factor known to suppress the type I interferon (IFN) response by inhibiting host cell transcription and by proteasomal degradation of a major antiviral IFN effector, the translation-inhibiting protein kinase PKR. Here, we identified components of the modular SCF (Skp1, Cul1, F-box protein)-type E3 ubiquitin ligases as mediators of PKR destruction by NSs. Small interfering RNAs (siRNAs) against the conserved SCF subunit Skp1 protected PKR from NSs-mediated degradation. Consequently, RVFV replication was severely reduced in Skp1-depleted cells when PKR was present. SCF complexes have a variable F-box protein subunit that determines substrate specificity for ubiquitination. We performed an siRNA screen for all (about 70) human F-box proteins and found FBXW11 to be involved in PKR degradation. The partial stabilization of PKR by FBXW11 depletion upregulated PKR autophosphorylation and phosphorylation of the PKR substrate eIF2α and caused a shutoff of host cell protein synthesis in RVFV-infected cells. To maximally protect PKR from the action of NSs, knockdown of structurally and functionally related FBXW1 (also known as β-TRCP1), in addition to FBXW11 deletion, was necessary. Consequently, NSs was found to interact with both FBXW11 and β-TRCP1. Thus, NSs eliminates the antiviral kinase PKR by recruitment of SCF-type E3 ubiquitin ligases containing FBXW11 and β-TRCP1 as substrate recognition subunits. This antagonism of PKR by NSs is essential for efficient RVFV replication in mammalian cells. Rift Valley fever virus is a pathogen of humans and animals that has the potential to spread from Africa and the Arabian Peninsula to other regions. A major virulence mechanism is the proteasomal degradation of the antiviral kinase PKR by the viral protein NSs. Here, we demonstrate that NSs

Identification of Wild Boar–Habitat Epidemiologic Cycle in African Swine Fever Epizootic

Science.gov (United States)

Ståhl, Karl; Guberti, Vittorio; Depner, Klaus

2018-01-01

The African swine fever epizootic in central and eastern European Union member states has a newly identified component involving virus transmission by wild boar and virus survival in the environment. Insights led to an update of the 3 accepted African swine fever transmission models to include a fourth cycle: wild boar–habitat. PMID:29553337

Infection and transmission of Rift Valley fever viruses lacking the NSs and/or NSm genes in mosquitoes: potential role for NSm in mosquito infection.

Directory of Open Access Journals (Sweden)

Mary B Crabtree

Full Text Available BACKGROUND: Rift Valley fever virus is an arthropod-borne human and animal pathogen responsible for large outbreaks of acute and febrile illness throughout Africa and the Arabian Peninsula. Reverse genetics technology has been used to develop deletion mutants of the virus that lack the NSs and/or NSm virulence genes and have been shown to be stable, immunogenic and protective against Rift Valley fever virus infection in animals. We assessed the potential for these deletion mutant viruses to infect and be transmitted by Aedes mosquitoes, which are the principal vectors for maintenance of the virus in nature and emergence of virus initiating disease outbreaks, and by Culex mosquitoes which are important amplification vectors. METHODOLOGY AND PRINCIPAL FINDINGS: Aedes aegypti and Culex quinquefasciatus mosquitoes were fed bloodmeals containing the deletion mutant viruses. Two weeks post-exposure mosquitoes were assayed for infection, dissemination, and transmission. In Ae. aegypti, infection and transmission rates of the NSs deletion virus were similar to wild type virus while dissemination rates were significantly reduced. Infection and dissemination rates for the NSm deletion virus were lower compared to wild type. Virus lacking both NSs and NSm failed to infect Ae. aegypti. In Cx. quinquefasciatus, infection rates for viruses lacking NSm or both NSs and NSm were lower than for wild type virus. CONCLUSIONS/SIGNIFICANCE: In both species, deletion of NSm or both NSs and NSm reduced the infection and transmission potential of the virus. Deletion of both NSs and NSm resulted in the highest level of attenuation of virus replication. Deletion of NSm alone was sufficient to nearly abolish infection in Aedes aegypti mosquitoes, indicating an important role for this protein. The double deleted viruses represent an ideal vaccine profile in terms of environmental containment due to lack of ability to efficiently infect and be transmitted by mosquitoes.

Infection and transmission of Rift Valley fever viruses lacking the NSs and/or NSm genes in mosquitoes: potential role for NSm in mosquito infection.

Science.gov (United States)

Crabtree, Mary B; Kent Crockett, Rebekah J; Bird, Brian H; Nichol, Stuart T; Erickson, Bobbie Rae; Biggerstaff, Brad J; Horiuchi, Kalanthe; Miller, Barry R

2012-01-01

Rift Valley fever virus is an arthropod-borne human and animal pathogen responsible for large outbreaks of acute and febrile illness throughout Africa and the Arabian Peninsula. Reverse genetics technology has been used to develop deletion mutants of the virus that lack the NSs and/or NSm virulence genes and have been shown to be stable, immunogenic and protective against Rift Valley fever virus infection in animals. We assessed the potential for these deletion mutant viruses to infect and be transmitted by Aedes mosquitoes, which are the principal vectors for maintenance of the virus in nature and emergence of virus initiating disease outbreaks, and by Culex mosquitoes which are important amplification vectors. Aedes aegypti and Culex quinquefasciatus mosquitoes were fed bloodmeals containing the deletion mutant viruses. Two weeks post-exposure mosquitoes were assayed for infection, dissemination, and transmission. In Ae. aegypti, infection and transmission rates of the NSs deletion virus were similar to wild type virus while dissemination rates were significantly reduced. Infection and dissemination rates for the NSm deletion virus were lower compared to wild type. Virus lacking both NSs and NSm failed to infect Ae. aegypti. In Cx. quinquefasciatus, infection rates for viruses lacking NSm or both NSs and NSm were lower than for wild type virus. In both species, deletion of NSm or both NSs and NSm reduced the infection and transmission potential of the virus. Deletion of both NSs and NSm resulted in the highest level of attenuation of virus replication. Deletion of NSm alone was sufficient to nearly abolish infection in Aedes aegypti mosquitoes, indicating an important role for this protein. The double deleted viruses represent an ideal vaccine profile in terms of environmental containment due to lack of ability to efficiently infect and be transmitted by mosquitoes.

Rift Valley fever virus NSs protein promotes post-transcriptional downregulation of protein kinase PKR and inhibits eIF2alpha phosphorylation.

Directory of Open Access Journals (Sweden)

Tetsuro Ikegami

2009-02-01

Full Text Available Rift Valley fever virus (RVFV (genus Phlebovirus, family Bunyaviridae is a negative-stranded RNA virus with a tripartite genome. RVFV is transmitted by mosquitoes and causes fever and severe hemorrhagic illness among humans, and fever and high rates of abortions in livestock. A nonstructural RVFV NSs protein inhibits the transcription of host mRNAs, including interferon-beta mRNA, and is a major virulence factor. The present study explored a novel function of the RVFV NSs protein by testing the replication of RVFV lacking the NSs gene in the presence of actinomycin D (ActD or alpha-amanitin, both of which served as a surrogate of the host mRNA synthesis suppression function of the NSs. In the presence of the host-transcriptional inhibitors, the replication of RVFV lacking the NSs protein, but not that carrying NSs, induced double-stranded RNA-dependent protein kinase (PKR-mediated eukaryotic initiation factor (eIF2alpha phosphorylation, leading to the suppression of host and viral protein translation. RVFV NSs promoted post-transcriptional downregulation of PKR early in the course of the infection and suppressed the phosphorylated eIF2alpha accumulation. These data suggested that a combination of RVFV replication and NSs-induced host transcriptional suppression induces PKR-mediated eIF2alpha phosphorylation, while the NSs facilitates efficient viral translation by downregulating PKR and inhibiting PKR-mediated eIF2alpha phosphorylation. Thus, the two distinct functions of the NSs, i.e., the suppression of host transcription, including that of type I interferon mRNAs, and the downregulation of PKR, work together to prevent host innate antiviral functions, allowing efficient replication and survival of RVFV in infected mammalian hosts.

Katayama fever in scuba divers - A report of 3 cases | Evans | South ...

African Journals Online (AJOL)

Katayama fever in scuba divers - A report of 3 cases. A.C. Evans, D.J. Martin, B.D. Ginsburg. Abstract. Katayama fever or acute schistosomiasis probably occurs more commonly than is recorded. Interviews with a 3-man scuba diving team who had had contact with a large dam in an ·endemic area of the eastern Transvaal ...

Climate Influence on Emerging Risk Areas for Rift Valley Fever Epidemics in Tanzania.

Science.gov (United States)

Mweya, Clement N; Mboera, Leonard E G; Kimera, Sharadhuli I

2017-07-01

Rift Valley Fever (RVF) is a climate-related arboviral infection of animals and humans. Climate is thought to represent a threat toward emerging risk areas for RVF epidemics globally. The objective of this study was to evaluate influence of climate on distribution of suitable breeding habitats for Culex pipiens complex, potential mosquito vector responsible for transmission and distribution of disease epidemics risk areas in Tanzania. We used ecological niche models to estimate potential distribution of disease risk areas based on vectors and disease co-occurrence data approach. Climatic variables for the current and future scenarios were used as model inputs. Changes in mosquito vectors' habitat suitability in relation to disease risk areas were estimated. We used partial receiver operating characteristic and the area under the curves approach to evaluate model predictive performance and significance. Habitat suitability for Cx. pipiens complex indicated broad-scale potential for change and shift in the distribution of the vectors and disease for both 2020 and 2050 climatic scenarios. Risk areas indicated more intensification in the areas surrounding Lake Victoria and northeastern part of the country through 2050 climate scenario. Models show higher probability of emerging risk areas spreading toward the western parts of Tanzania from northeastern areas and decrease in the southern part of the country. Results presented here identified sites for consideration to guide surveillance and control interventions to reduce risk of RVF disease epidemics in Tanzania. A collaborative approach is recommended to develop and adapt climate-related disease control and prevention strategies.

NSs protein of rift valley fever virus induces the specific degradation of the double-stranded RNA-dependent protein kinase.

Science.gov (United States)

Habjan, Matthias; Pichlmair, Andreas; Elliott, Richard M; Overby, Anna K; Glatter, Timo; Gstaiger, Matthias; Superti-Furga, Giulio; Unger, Hermann; Weber, Friedemann

2009-05-01

Rift Valley fever virus (RVFV) continues to cause large outbreaks of acute febrile and often fatal illness among humans and domesticated animals in Africa, Saudi Arabia, and Yemen. The high pathogenicity of this bunyavirus is mainly due to the viral protein NSs, which was shown to prevent transcriptional induction of the antivirally active type I interferons (alpha/beta interferon [IFN-alpha/beta]). Viruses lacking the NSs gene induce synthesis of IFNs and are therefore attenuated, whereas the noninducing wild-type RVFV strains can only be inhibited by pretreatment with IFN. We demonstrate here in vitro and in vivo that a substantial part of the antiviral activity of IFN against RVFV is due to a double-stranded RNA-dependent protein kinase (PKR). PKR-mediated virus inhibition, however, was much more pronounced for the strain Clone 13 with NSs deleted than for the NSs-expressing strain ZH548. In vivo, Clone 13 was nonpathogenic for wild-type (wt) mice but could regain pathogenicity if mice lacked the PKR gene. ZH548, in contrast, killed both wt and PKR knockout mice indiscriminately. ZH548 was largely resistant to the antiviral properties of PKR because RVFV NSs triggered the specific degradation of PKR via the proteasome. The NSs proteins of the related but less virulent sandfly fever Sicilian virus and La Crosse virus, in contrast, had no such anti-PKR activity despite being efficient suppressors of IFN induction. Our data suggest that RVFV NSs has gained an additional anti-IFN function that may explain the extraordinary pathogenicity of this virus.

Q fever in Egypt: Epidemiological survey of Coxiella burnetii specific antibodies in cattle, buffaloes, sheep, goats and camels.

Directory of Open Access Journals (Sweden)

Jessica Klemmer

Full Text Available Q fever is a zoonotic disease caused by the bacterium Coxiella burnetii. Clinical presentation in humans varies from asymptomatic to flu-like illness and severe sequelae may be seen. Ruminants are often sub-clinically infected or show reproductive disorders such as abortions. In Egypt, only limited data on the epidemiology of Q fever in animals are available. Using a stratified two stage random sampling approach, we evaluated the prevalence of Coxiella burnetii specific antibodies among ruminants and camels in 299 herds. A total of 2,699 blood samples was investigated using enzyme-linked-immunosorbent assay (ELISA. Coxiella burnetii specific antibodies were detected in 40.7% of camels (215/528, 19.3% of cattle (162/840, 11.2% of buffaloes (34/304, 8.9% of sheep (64/716 and 6.8% of goats (21/311, respectively. Odds of seropositivity were significantly higher for cattle (aOR: 3.17; 95% CI: 1.96-5.13 and camels (aOR: 9.75; 95% CI: 6.02-15.78. Significant differences in seropositivity were also found between domains (Western Desert, Eastern Desert and Nile Valley and Delta and 25 governorates (p 0.05. Only 8.7% of the interviewed people living on the farms consumed raw camel milk and none reported prior knowledge on Q fever. Findings from this nationwide study show that exposure to Coxiella burnetii is common in ruminants and camels. Disease awareness among physicians, veterinarians and animal owners has to be raised. Future epidemiological investigations have to elucidate the impact of Q fever on human health and on the economy of Egypt.

Immunogenicity and efficacy of a chimpanzee adenovirus-vectored Rift Valley fever vaccine in mice.

Science.gov (United States)

Warimwe, George M; Lorenzo, Gema; Lopez-Gil, Elena; Reyes-Sandoval, Arturo; Cottingham, Matthew G; Spencer, Alexandra J; Collins, Katharine A; Dicks, Matthew D J; Milicic, Anita; Lall, Amar; Furze, Julie; Turner, Alison V; Hill, Adrian V S; Brun, Alejandro; Gilbert, Sarah C

2013-12-05

Rift Valley Fever (RVF) is a viral zoonosis that historically affects livestock production and human health in sub-Saharan Africa, though epizootics have also occurred in the Arabian Peninsula. Whilst an effective live-attenuated vaccine is available for livestock, there is currently no licensed human RVF vaccine. Replication-deficient chimpanzee adenovirus (ChAd) vectors are an ideal platform for development of a human RVF vaccine, given the low prevalence of neutralizing antibodies against them in the human population, and their excellent safety and immunogenicity profile in human clinical trials of vaccines against a wide range of pathogens. Here, in BALB/c mice, we evaluated the immunogenicity and efficacy of a replication-deficient chimpanzee adenovirus vector, ChAdOx1, encoding the RVF virus envelope glycoproteins, Gn and Gc, which are targets of virus neutralizing antibodies. The ChAdOx1-GnGc vaccine was assessed in comparison to a replication-deficient human adenovirus type 5 vector encoding Gn and Gc (HAdV5-GnGc), a strategy previously shown to confer protective immunity against RVF in mice. A single immunization with either of the vaccines conferred protection against RVF virus challenge eight weeks post-immunization. Both vaccines elicited RVF virus neutralizing antibody and a robust CD8+ T cell response. Together the results support further development of RVF vaccines based on replication-deficient adenovirus vectors, with ChAdOx1-GnGc being a potential candidate for use in future human clinical trials.

Rocky Mountain spotted fever from an unexpected tick vector in Arizona.

Science.gov (United States)

Demma, Linda J; Traeger, Marc S; Nicholson, William L; Paddock, Christopher D; Blau, Dianna M; Eremeeva, Marina E; Dasch, Gregory A; Levin, Michael L; Singleton, Joseph; Zaki, Sherif R; Cheek, James E; Swerdlow, David L; McQuiston, Jennifer H

2005-08-11

Rocky Mountain spotted fever is a life-threatening, tick-borne disease caused by Rickettsia rickettsii. This disease is rarely reported in Arizona, and the principal vectors, Dermacentor species ticks, are uncommon in the state. From 2002 through 2004, a focus of Rocky Mountain spotted fever was investigated in rural eastern Arizona. We obtained blood and tissue specimens from patients with suspected Rocky Mountain spotted fever and ticks from patients' homesites. Serologic, molecular, immunohistochemical, and culture assays were performed to identify the causative agent. On the basis of specific laboratory criteria, patients were classified as having confirmed or probable Rocky Mountain spotted fever infection. A total of 16 patients with Rocky Mountain spotted fever infection (11 with confirmed and 5 with probable infection) were identified. Of these patients, 13 (81 percent) were children 12 years of age or younger, 15 (94 percent) were hospitalized, and 2 (12 percent) died. Dense populations of Rhipicephalus sanguineus ticks were found on dogs and in the yards of patients' homesites. All patients with confirmed Rocky Mountain spotted fever had contact with tick-infested dogs, and four had a reported history of tick bite preceding the illness. R. rickettsii DNA was detected in nonengorged R. sanguineus ticks collected at one home, and R. rickettsii isolates were cultured from these ticks. This investigation documents the presence of Rocky Mountain spotted fever in eastern Arizona, with common brown dog ticks (R. sanguineus) implicated as a vector of R. rickettsii. The broad distribution of this common tick raises concern about its potential to transmit R. rickettsii in other settings. Copyright 2005 Massachusetts Medical Society.

p53 Activation following Rift Valley fever virus infection contributes to cell death and viral production.

Directory of Open Access Journals (Sweden)

Dana Austin

Full Text Available Rift Valley fever virus (RVFV is an emerging viral zoonosis that is responsible for devastating outbreaks among livestock and is capable of causing potentially fatal disease in humans. Studies have shown that upon infection, certain viruses have the capability of utilizing particular cellular signaling pathways to propagate viral infection. Activation of p53 is important for the DNA damage signaling cascade, initiation of apoptosis, cell cycle arrest and transcriptional regulation of multiple genes. The current study focuses on the role of p53 signaling in RVFV infection and viral replication. These results show an up-regulation of p53 phosphorylation at several serine sites after RVFV MP-12 infection that is highly dependent on the viral protein NSs. qRT-PCR data showed a transcriptional up-regulation of several p53 targeted genes involved in cell cycle and apoptosis regulation following RVFV infection. Cell viability assays demonstrate that loss of p53 results in less RVFV induced cell death. Furthermore, decreased viral titers in p53 null cells indicate that RVFV utilizes p53 to enhance viral production. Collectively, these experiments indicate that the p53 signaling pathway is utilized during RVFV infection to induce cell death and increase viral production.

Ecological niche modeling and land cover risk areas for rift valley fever vector, culex tritaeniorhynchus giles in Jazan, Saudi Arabia.

Science.gov (United States)

Sallam, Mohamed F; Al Ahmed, Azzam M; Abdel-Dayem, Mahmoud S; Abdullah, Mohamed A R

2013-01-01

The mosquito, Culex tritaeniorhynchus Giles is a prevalent and confirmed Rift Valley Fever virus (RVFV) vector. This vector, in association with Aedimorphus arabiensis (Patton), was responsible for causing the outbreak of 2000 in Jazan Province, Saudi Arabia. Larval occurrence records and a total of 19 bioclimatic and three topographic layers imported from Worldclim Database were used to predict the larval suitable breeding habitats for this vector in Jazan Province using ArcGIS ver.10 and MaxEnt modeling program. Also, a supervised land cover classification from SPOT5 imagery was developed to assess the land cover distribution within the suitable predicted habitats. Eleven bioclimatic and slope attributes were found to be the significant predictors for this larval suitable breeding habitat. Precipitation and temperature were strong predictors of mosquito distribution. Among six land cover classes, the linear regression model (LM) indicated wet muddy substrate is significantly associated with high-very high suitable predicted habitats (R(2) = 73.7%, Presearchers.

Prediction, assessment of the Rift Valley fever activity in East and Southern Africa 2006-2008 and possible vector control strategies.

Science.gov (United States)

Anyamba, Assaf; Linthicum, Kenneth J; Small, Jennifer; Britch, Seth C; Pak, Edwin; de La Rocque, Stephane; Formenty, Pierre; Hightower, Allen W; Breiman, Robert F; Chretien, Jean-Paul; Tucker, Compton J; Schnabel, David; Sang, Rosemary; Haagsma, Karl; Latham, Mark; Lewandowski, Henry B; Magdi, Salih Osman; Mohamed, Mohamed Ally; Nguku, Patrick M; Reynes, Jean-Marc; Swanepoel, Robert

2010-08-01

Historical outbreaks of Rift Valley fever (RVF) since the early 1950s have been associated with cyclical patterns of the El Niño/Southern Oscillation (ENSO) phenomenon, which results in elevated and widespread rainfall over the RVF endemic areas of Africa. Using satellite measurements of global and regional elevated sea surface temperatures, elevated rainfall, and satellite derived-normalized difference vegetation index data, we predicted with lead times of 2-4 months areas where outbreaks of RVF in humans and animals were expected and occurred in the Horn of Africa, Sudan, and Southern Africa at different time periods from September 2006 to March 2008. Predictions were confirmed by entomological field investigations of virus activity and by reported cases of RVF in human and livestock populations. This represents the first series of prospective predictions of RVF outbreaks and provides a baseline for improved early warning, control, response planning, and mitigation into the future.

Identification of central Kenyan Rift Valley Fever virus vector habitats with Landsat TM and evaluation of their flooding status with airborne imaging radar

Science.gov (United States)

Pope, K. O.; Sheffner, E. J.; Linthicum, K. J.; Bailey, C. L.; Logan, T. M.; Kasischke, E. S.; Birney, K.; Njogu, A. R.; Roberts, C. R.

1992-01-01

Rift Valley Fever (RVF) is a mosquito-borne virus that affects livestock and humans in Africa. Landsat TM data are shown to be effective in identifying dambos, intermittently flooded areas that are potential mosquite breeding sites, in an area north of Nairobi, Kenya. Positive results were obtained from a limited test of flood detection in dambos with airborne high resolution L, C, and X band multipolarization SAR imagery. L and C bands were effective in detecting flooded dambos, but LHH was by far the best channel for discrimination between flooded and nonflooded sites in both sedge and short-grass environments. This study demonstrates the feasibility of a combined passive and active remote sensing program for monitoring the location and condition of RVF vector habitats, thus making future control of the disease more promising.

Gravity and magnetic data of Midway Valley, southwest Nevada

International Nuclear Information System (INIS)

Ponce, D.A.; Langenheim, V.E.; Sikora, R.F.

1993-01-01

Detailed gravity and ground magnetic data collected along five traverses across Midway Valley on the eastern flank of Yucca Mountain in southwest Nevada are described. These data were collected as part of an effort to evaluate faulting in the vicinity of proposed surface facilities for a potential nuclear waste repository at Yucca Mountain. Geophysical data show that Midway Valley is bounded by large gravity and magnetic anomalies associated with the Bow Ridge and Paintbrush Canyon faults, on the west side of Exile Hill and on the west flank of Fran Ridge, respectively. In addition, Midway Valley itself is characterized by a number of small-amplitude anomalies that probably reflect small-scale faulting beneath Midway Valley

Identification of mutations in the M RNA of a candidate vaccine strain of Rift Valley fever virus.

Science.gov (United States)

Takehara, K; Min, M K; Battles, J K; Sugiyama, K; Emery, V C; Dalrymple, J M; Bishop, D H

1989-04-01

The M RNA species of a candidate vaccine strain of Rift Valley fever virus (RVFV ZH-548M12), derived by consecutive high level mutagenesis using 5-fluorouracil (H. Caplen, C. J. Peters, and D. H. L. Bishop, J. Gen. Virol., 66, 2271-2277, 1985), has been cloned and the cDNA sequenced. The data have been compared to those obtained for the parent virus strain RVFV ZH-548 as well as the previously published data for RVFV ZH-501 (M. S. Collett, A. F. Purchio, K. Keegan, S. Frazier, W. Hays, D. K. Anderson, M. D. Parker, C. Schmaljohn, J. Schmidt, and J. M. Dalrymple, Virology, 144, 228-245, 1985). Some eight nucleotide and three amino acid differences were identified between the M RNAs of ZH-501 and ZH-548. Between the M RNAs of ZH-548 and that of the M12 mutant there were 12 nucleotide and 7 amino acid changes. Unique to the mutant virus is a new AUG codon upstream of that which initiates the open reading frame of the RVFV M gene product (the viral glycoprotein precursor). The significance of this and other differences in the mutant RNA with regard to the derivation and potential attenuation of the candidate vaccine is discussed.

Potential Risk Areas of Aedes albopictus in South-Eastern Iran: A Vector of Dengue Fever, Zika, and Chikungunya

Directory of Open Access Journals (Sweden)

Jalil Nejati

2017-09-01

Full Text Available The possibility of the rapid and global spread of Zika, chikungunya, yellow fever, and dengue fever by Aedes albopictus is well documented and may be facilitated by changes in climate. To avert and manage health risks, climatic and topographic information can be used to model and forecast which areas may be most prone to the establishment of Ae. albopictus. We aimed to weigh and prioritize the predictive value of various meteorological and climatic variables on distributions of Ae. albopictus in south-eastern Iran using the Analytical Hierarchy Process. Out of eight factors used to predict the presence of Ae. albopictus, the highest weighted were land use, followed by temperature, altitude, and precipitation. The inconsistency of this analysis was 0.03 with no missing judgments. The areas predicted to be most at risk of Ae. albopictus-borne diseases were mapped using Geographic Information Systems and remote sensing data. Five-year (2011–2015 meteorological data was collected from 11 meteorological stations and other data was acquired from Landsat and Terra satellite images. Southernmost regions were at greatest risk of Ae. albopictus colonization as well as more urban sites connected by provincial roads. This is the first study in Iran to determine the regional probability of Ae. albopictus establishment. Monitoring and collection of Ae. albopictus from the environment confirmed our projections, though on-going field work is necessary to track the spread of this vector of life-threatening disease.

The role of signal transducer and activator of transcription 3 in Rift Valley fever virus infection

International Nuclear Information System (INIS)

Pinkham, Chelsea; An, Soyeon; Lundberg, Lindsay; Bansal, Neha; Benedict, Ashwini; Narayanan, Aarthi; Kehn-Hall, Kylene

2016-01-01

Rift Valley fever (RVF) is a zoonotic disease that can cause severe illness in humans and livestock, triggering spontaneous abortion in almost 100% of pregnant ruminants. In this study, we demonstrate that signal transducer and activator of transcription 3 (STAT3) is phosphorylated on its conserved tyrosine residue (Y705) following RVFV infection. This phosphorylation was dependent on a major virulence factor, the viral nonstructural protein NSs. Loss of STAT3 had little effect on viral replication, but rather resulted in cells being more susceptible to RVFV-induced cell death. Phosphorylated STAT3 translocated to the nucleus, coinciding with inhibition of fos, jun, and nr4a2 gene expression, and the presence of STAT3 and NSs at the nr4a2 promoter. NSs was found predominantly in the cytoplasm of STAT3 null cells, indicating that STAT3 influences NSs nuclear localization. Collectively, these data demonstrate that STAT3 functions in a pro-survival capacity through modulation of NSs localization. - Highlights: • STAT3 is phosphorylated on tyrosine residue 705 following RVFV infection. • Phosphorylation of STAT3 was dependent on the viral protein NSs. • STAT3 -/- MEFs were more susceptible to RVFV-induced cell death. • Loss of STAT3 led to an increase in pro-apoptotic gene expression. • STAT3 functions in a pro-survival capacity by modulation of NSs localization.

NSs protein of rift valley fever virus promotes posttranslational downregulation of the TFIIH subunit p62.

Science.gov (United States)

Kalveram, Birte; Lihoradova, Olga; Ikegami, Tetsuro

2011-07-01

Rift Valley fever virus (RVFV; family Bunyaviridae, genus Phlebovirus) is an important emerging pathogen of humans and ruminants. Its NSs protein has previously been identified as a major virulence factor that suppresses host defense through three distinct mechanisms: it directly inhibits beta interferon (IFN-β) promoter activity, it promotes the degradation of double-stranded RNA-dependent protein kinase (PKR), and it suppresses host transcription by disrupting the assembly of the basal transcription factor TFIIH through sequestration of its p44 subunit. Here, we report that in addition to PKR, NSs also promotes the degradation of the TFIIH subunit p62. Infection of cells with the RVFV MP-12 vaccine strain reduced p62 protein levels to below the detection limit early in the course of infection. This NSs-mediated downregulation of p62 was posttranslational, as it was unaffected by pharmacological inhibition of transcription or translation and MP-12 infection had no effect on p62 mRNA levels. Treatment of cells with proteasome inhibitors but not inhibition of lysosomal acidification or nuclear export resulted in a stabilization of p62 in the presence of NSs. Furthermore, p62 could be coprecipitated with NSs from lysates of infected cells. These data suggest that the RVFV NSs protein is able to interact with the TFIIH subunit p62 inside infected cells and promotes its degradation, which can occur directly in the nucleus.

The role of signal transducer and activator of transcription 3 in Rift Valley fever virus infection

Energy Technology Data Exchange (ETDEWEB)

Pinkham, Chelsea; An, Soyeon; Lundberg, Lindsay; Bansal, Neha; Benedict, Ashwini; Narayanan, Aarthi; Kehn-Hall, Kylene, E-mail: kkehnhal@gmu.edu

2016-09-15

Rift Valley fever (RVF) is a zoonotic disease that can cause severe illness in humans and livestock, triggering spontaneous abortion in almost 100% of pregnant ruminants. In this study, we demonstrate that signal transducer and activator of transcription 3 (STAT3) is phosphorylated on its conserved tyrosine residue (Y705) following RVFV infection. This phosphorylation was dependent on a major virulence factor, the viral nonstructural protein NSs. Loss of STAT3 had little effect on viral replication, but rather resulted in cells being more susceptible to RVFV-induced cell death. Phosphorylated STAT3 translocated to the nucleus, coinciding with inhibition of fos, jun, and nr4a2 gene expression, and the presence of STAT3 and NSs at the nr4a2 promoter. NSs was found predominantly in the cytoplasm of STAT3 null cells, indicating that STAT3 influences NSs nuclear localization. Collectively, these data demonstrate that STAT3 functions in a pro-survival capacity through modulation of NSs localization. - Highlights: • STAT3 is phosphorylated on tyrosine residue 705 following RVFV infection. • Phosphorylation of STAT3 was dependent on the viral protein NSs. • STAT3 -/- MEFs were more susceptible to RVFV-induced cell death. • Loss of STAT3 led to an increase in pro-apoptotic gene expression. • STAT3 functions in a pro-survival capacity by modulation of NSs localization.

Transient electromagnetic mapping of clay units in the San Luis Valley, Colorado

Science.gov (United States)

Fitterman, David V.; Grauch, V.J.S.

2010-01-01

Transient electromagnetic soundings were used to obtain information needed to refine hydrologic models of the San Luis Valley, Colorado. The soundings were able to map an aquitard called the blue clay that separates an unconfined surface aquifer from a deeper confined aquifer. The blue clay forms a conductor with an average resistivity of 6.9 ohm‐m. Above the conductor are found a mixture of gray clay and sand. The gray clay has an average resistivity of 21 ohm‐m, while the sand has a resistivity of greater than 100 ohm‐m. The large difference in resistivity of these units makes mapping them with a surface geophysical method relatively easy. The blue clay was deposited at the bottom of Lake Alamosa which filled most of the San Luis Valley during the Pleistocene. The geometry of the blue clay is influenced by a graben on the eastern side of the valley. The depth to the blue clay is greater over the graben. Along the eastern edge of valley the blue clay appears to be truncated by faults.

Virulence factor NSs of rift valley fever virus recruits the F-box protein FBXO3 to degrade subunit p62 of general transcription factor TFIIH.

Science.gov (United States)

Kainulainen, Markus; Habjan, Matthias; Hubel, Philipp; Busch, Laura; Lau, Simone; Colinge, Jacques; Superti-Furga, Giulio; Pichlmair, Andreas; Weber, Friedemann

2014-03-01

The nonstructural protein NSs is the main virulence factor of Rift Valley fever virus (RVFV; family Bunyaviridae, genus Phlebovirus), a serious pathogen of livestock and humans in Africa. RVFV NSs blocks transcriptional upregulation of antiviral type I interferons (IFN) and destroys the general transcription factor TFIIH subunit p62 via the ubiquitin/proteasome pathway. Here, we identified a subunit of E3 ubiquitin ligases, F-box protein FBXO3, as a host cell interactor of NSs. Small interfering RNA (siRNA)-mediated depletion of FBXO3 rescued p62 protein levels in RVFV-infected cells and elevated IFN transcription by 1 order of magnitude. NSs interacts with the full-length FBXO3 protein as well as with a truncated isoform that lacks the C-terminal acidic and poly(R)-rich domains. These isoforms are present in both the nucleus and the cytoplasm. NSs exclusively removes the nuclear pool of full-length FBXO3, likely due to consumption during the degradation process. F-box proteins form the variable substrate recognition subunit of the so-called SCF ubiquitin ligases, which also contain the constant components Skp1, cullin 1 (or cullin 7), and Rbx1. siRNA knockdown of Skp1 also protected p62 from degradation, suggesting involvement in NSs action. However, knockdown of cullin 1, cullin 7, or Rbx1 could not rescue p62 degradation by NSs. Our data show that the enzymatic removal of p62 via the host cell factor FBXO3 is a major mechanism of IFN suppression by RVFV. Rift Valley fever virus is a serious emerging pathogen of animals and humans. Its main virulence factor, NSs, enables unhindered virus replication by suppressing the antiviral innate immune system. We identified the E3 ubiquitin ligase FBXO3 as a novel host cell interactor of NSs. NSs recruits FBXO3 to destroy the general host cell transcription factor TFIIH-p62, resulting in suppression of the transcriptional upregulation of innate immunity.

Rift Valley fever virus NSs inhibits host transcription independently of the degradation of dsRNA-dependent protein kinase PKR.

Science.gov (United States)

Kalveram, Birte; Lihoradova, Olga; Indran, Sabarish V; Lokugamage, Nandadeva; Head, Jennifer A; Ikegami, Tetsuro

2013-01-20

Rift Valley fever virus (RVFV) encodes one major virulence factor, the NSs protein. NSs suppresses host general transcription, including interferon (IFN)-β mRNA synthesis, and promotes degradation of the dsRNA-dependent protein kinase (PKR). We generated a novel RVFV mutant (rMP12-NSsR173A) specifically lacking the function to promote PKR degradation. rMP12-NSsR173A infection induces early phosphorylation of eIF2α through PKR activation, while retaining the function to inhibit host general transcription including IFN-β gene inhibition. MP-12 NSs but not R173A NSs binds to wt PKR. R173A NSs formed filamentous structure in nucleus in a mosaic pattern, which was distinct from MP-12 NSs filament pattern. Due to early phosphorylation of eIF2α, rMP12-NSsR173A could not efficiently accumulate viral proteins. Our results suggest that NSs-mediated host general transcription suppression occurs independently of PKR degradation, while the PKR degradation is important to inhibit the phosphorylation of eIF2α in infected cells undergoing host general transcription suppression. Copyright © 2012 Elsevier Inc. All rights reserved.

Nonstructural NSs protein of rift valley fever virus interacts with pericentromeric DNA sequences of the host cell, inducing chromosome cohesion and segregation defects.

Science.gov (United States)

Mansuroglu, Z; Josse, T; Gilleron, J; Billecocq, A; Leger, P; Bouloy, M; Bonnefoy, E

2010-01-01

Rift Valley fever virus (RVFV) is an emerging, highly pathogenic virus; RVFV infection can lead to encephalitis, retinitis, or fatal hepatitis associated with hemorrhagic fever in humans, as well as death, abortions, and fetal deformities in animals. RVFV nonstructural NSs protein, a major factor of the virulence, forms filamentous structures in the nuclei of infected cells. In order to further understand RVFV pathology, we investigated, by chromatin immunoprecipitation, immunofluorescence, fluorescence in situ hybridization, and confocal microscopy, the capacity of NSs to interact with the host genome. Our results demonstrate that even though cellular DNA is predominantly excluded from NSs filaments, NSs interacts with some specific DNA regions of the host genome such as clusters of pericentromeric gamma-satellite sequence. Targeting of these sequences by NSs was correlated with the induction of chromosome cohesion and segregation defects in RVFV-infected murine, as well as sheep cells. Using recombinant nonpathogenic virus rZHDeltaNSs210-230, expressing a NSs protein deleted of its region of interaction with cellular factor SAP30, we showed that the NSs-SAP30 interaction was essential for NSs to target pericentromeric sequences, as well as for induction of chromosome segregation defects. The effect of RVFV upon the inheritance of genetic information is discussed with respect to the pathology associated with fetal deformities and abortions, highlighting the main role played by cellular cofactor SAP30 on the establishment of NSs interactions with host DNA sequences and RVFV pathogenesis.

Comparison of Rift Valley fever virus replication in North American livestock and wildlife cell lines.

Science.gov (United States)

Gaudreault, Natasha N; Indran, Sabarish V; Bryant, P K; Richt, Juergen A; Wilson, William C

2015-01-01

Rift Valley fever virus (RVFV) causes disease outbreaks across Africa and the Arabian Peninsula, resulting in high morbidity and mortality among young domestic livestock, frequent abortions in pregnant animals, and potentially severe or fatal disease in humans. The possibility of RVFV spreading to the United States or other countries worldwide is of significant concern to animal and public health, livestock production, and trade. The mechanism for persistence of RVFV during inter-epidemic periods may be through mosquito transovarial transmission and/or by means of a wildlife reservoir. Field investigations in endemic areas and previous in vivo studies have demonstrated that RVFV can infect a wide range of animals, including indigenous wild ruminants of Africa. Yet no predominant wildlife reservoir has been identified, and gaps in our knowledge of RVFV permissive hosts still remain. In North America, domestic goats, sheep, and cattle are susceptible hosts for RVFV and several competent vectors exist. Wild ruminants such as deer might serve as a virus reservoir and given their abundance, wide distribution, and overlap with livestock farms and human populated areas could represent an important risk factor. The objective of this study was to assess a variety of cell lines derived from North American livestock and wildlife for susceptibility and permissiveness to RVFV. Results of this study suggest that RVFV could potentially replicate in native deer species such as white-tailed deer, and possibly a wide range of non-ruminant animals. This work serves to guide and support future animal model studies and risk model assessment regarding this high-consequence zoonotic pathogen.

Post-exposure vaccination with MP-12 lacking NSs protects mice against lethal Rift Valley fever virus challenge.

Science.gov (United States)

Gowen, Brian B; Bailey, Kevin W; Scharton, Dionna; Vest, Zachery; Westover, Jonna B; Skirpstunas, Ramona; Ikegami, Tetsuro

2013-05-01

Rift Valley fever virus (RVFV) causes severe disease in humans and livestock. There are currently no approved antivirals or vaccines for the treatment or prevention of RVF disease in humans. A major virulence factor of RVFV is the NSs protein, which inhibits host transcription including the interferon (IFN)-β gene and promotes the degradation of dsRNA-dependent protein kinase, PKR. We analyzed the efficacy of the live-attenuated MP-12 vaccine strain and MP-12 variants that lack the NSs protein as post-exposure vaccinations. Although parental MP-12 failed to elicit a protective effect in mice challenged with wild-type (wt) RVFV by the intranasal route, significant protection was demonstrated by vaccination with MP-12 strains lacking NSs when they were administered at 20-30 min post-exposure. Viremia and virus replication in liver, spleen and brain were also inhibited by post-exposure vaccination with MP-12 lacking NSs. The protective effect was mostly lost when vaccination was delayed 6 or 24 h after intranasal RVFV challenge. When mice were challenged subcutaneously, efficacy of MP-12 lacking NSs was diminished, most likely due to more rapid dissemination of wt RVFV. Our findings suggest that post-exposure vaccination with MP-12 lacking NSs may be developed as a novel post-exposure treatment to prevent RVF. Copyright © 2013 Elsevier B.V. All rights reserved.

The AFHSC-Division of GEIS Operations Predictive Surveillance Program: a multidisciplinary approach for the early detection and response to disease outbreaks.

Science.gov (United States)

Witt, Clara J; Richards, Allen L; Masuoka, Penny M; Foley, Desmond H; Buczak, Anna L; Musila, Lillian A; Richardson, Jason H; Colacicco-Mayhugh, Michelle G; Rueda, Leopoldo M; Klein, Terry A; Anyamba, Assaf; Small, Jennifer; Pavlin, Julie A; Fukuda, Mark M; Gaydos, Joel; Russell, Kevin L; Wilkerson, Richard C; Gibbons, Robert V; Jarman, Richard G; Myint, Khin S; Pendergast, Brian; Lewis, Sheri; Pinzon, Jorge E; Collins, Kathrine; Smith, Matthew; Pak, Edwin; Tucker, Compton; Linthicum, Kenneth; Myers, Todd; Mansour, Moustafa; Earhart, Ken; Kim, Heung Chul; Jiang, Ju; Schnabel, Dave; Clark, Jeffrey W; Sang, Rosemary C; Kioko, Elizabeth; Abuom, David C; Grieco, John P; Richards, Erin E; Tobias, Steven; Kasper, Matthew R; Montgomery, Joel M; Florin, Dave; Chretien, Jean-Paul; Philip, Trudy L

2011-03-04

The Armed Forces Health Surveillance Center, Division of Global Emerging Infections Surveillance and Response System Operations (AFHSC-GEIS) initiated a coordinated, multidisciplinary program to link data sets and information derived from eco-climatic remote sensing activities, ecologic niche modeling, arthropod vector, animal disease-host/reservoir, and human disease surveillance for febrile illnesses, into a predictive surveillance program that generates advisories and alerts on emerging infectious disease outbreaks. The program's ultimate goal is pro-active public health practice through pre-event preparedness, prevention and control, and response decision-making and prioritization. This multidisciplinary program is rooted in over 10 years experience in predictive surveillance for Rift Valley fever outbreaks in Eastern Africa. The AFHSC-GEIS Rift Valley fever project is based on the identification and use of disease-emergence critical detection points as reliable signals for increased outbreak risk. The AFHSC-GEIS predictive surveillance program has formalized the Rift Valley fever project into a structured template for extending predictive surveillance capability to other Department of Defense (DoD)-priority vector- and water-borne, and zoonotic diseases and geographic areas. These include leishmaniasis, malaria, and Crimea-Congo and other viral hemorrhagic fevers in Central Asia and Africa, dengue fever in Asia and the Americas, Japanese encephalitis (JE) and chikungunya fever in Asia, and rickettsial and other tick-borne infections in the U.S., Africa and Asia.

The AFHSC-Division of GEIS Operations Predictive Surveillance Program: a multidisciplinary approach for the early detection and response to disease outbreaks

Science.gov (United States)

2011-01-01

The Armed Forces Health Surveillance Center, Division of Global Emerging Infections Surveillance and Response System Operations (AFHSC-GEIS) initiated a coordinated, multidisciplinary program to link data sets and information derived from eco-climatic remote sensing activities, ecologic niche modeling, arthropod vector, animal disease-host/reservoir, and human disease surveillance for febrile illnesses, into a predictive surveillance program that generates advisories and alerts on emerging infectious disease outbreaks. The program’s ultimate goal is pro-active public health practice through pre-event preparedness, prevention and control, and response decision-making and prioritization. This multidisciplinary program is rooted in over 10 years experience in predictive surveillance for Rift Valley fever outbreaks in Eastern Africa. The AFHSC-GEIS Rift Valley fever project is based on the identification and use of disease-emergence critical detection points as reliable signals for increased outbreak risk. The AFHSC-GEIS predictive surveillance program has formalized the Rift Valley fever project into a structured template for extending predictive surveillance capability to other Department of Defense (DoD)-priority vector- and water-borne, and zoonotic diseases and geographic areas. These include leishmaniasis, malaria, and Crimea-Congo and other viral hemorrhagic fevers in Central Asia and Africa, dengue fever in Asia and the Americas, Japanese encephalitis (JE) and chikungunya fever in Asia, and rickettsial and other tick-borne infections in the U.S., Africa and Asia. PMID:21388561

Multi-faceted proteomic characterization of host protein complement of Rift Valley fever virus virions and identification of specific heat shock proteins, including HSP90, as important viral host factors.

Science.gov (United States)

Nuss, Jonathan E; Kehn-Hall, Kylene; Benedict, Ashwini; Costantino, Julie; Ward, Michael; Peyser, Brian D; Retterer, Cary J; Tressler, Lyal E; Wanner, Laura M; McGovern, Hugh F; Zaidi, Anum; Anthony, Scott M; Kota, Krishna P; Bavari, Sina; Hakami, Ramin M

2014-01-01

Rift Valley fever is a potentially fatal disease of humans and domestic animals caused by Rift Valley fever virus (RVFV). Infection with RVFV in ruminants can cause near 100% abortion rates and recent outbreaks in naïve human populations have suggested case fatality rates of greater than thirty percent. To elucidate the roles that host proteins play during RVFV infection, proteomic analysis of RVFV virions was conducted using complementary analytical approaches, followed by functional validation studies of select identified host factors. Coupling the more traditional Gel LC/MS/MS approach (SDS PAGE followed by liquid chromatography tandem mass spectrometry) with an alternative technique that preserves protein complexes allowed the protein complement of these viral particles to be thoroughly examined. In addition to viral proteins present within the virions and virion-associated host proteins, multiple macromolecular complexes were identified. Bioinformatic analysis showed that host chaperones were among over-represented protein families associated with virions, and functional experiments using siRNA gene silencing and small molecule inhibitors identified several of these heat shock proteins, including heat shock protein 90 (HSP90), as important viral host factors. Further analysis indicated that HSP inhibition effects occur during the replication/transcription phase of the virus life cycle, leading to significant lowering of viral titers without compromising the functional capacity of released virions. Overall, these studies provide much needed further insight into interactions between RVFV and host cells, increasing our understanding of the infection process and suggesting novel strategies for anti-viral development. In particular, considering that several HSP90 inhibitors have been advancing through clinical trials for cancer treatment, these results also highlight the exciting potential of repurposing HSP90 inhibitors to treat RVF.

Multi-faceted proteomic characterization of host protein complement of Rift Valley fever virus virions and identification of specific heat shock proteins, including HSP90, as important viral host factors.

Directory of Open Access Journals (Sweden)

Jonathan E Nuss

Full Text Available Rift Valley fever is a potentially fatal disease of humans and domestic animals caused by Rift Valley fever virus (RVFV. Infection with RVFV in ruminants can cause near 100% abortion rates and recent outbreaks in naïve human populations have suggested case fatality rates of greater than thirty percent. To elucidate the roles that host proteins play during RVFV infection, proteomic analysis of RVFV virions was conducted using complementary analytical approaches, followed by functional validation studies of select identified host factors. Coupling the more traditional Gel LC/MS/MS approach (SDS PAGE followed by liquid chromatography tandem mass spectrometry with an alternative technique that preserves protein complexes allowed the protein complement of these viral particles to be thoroughly examined. In addition to viral proteins present within the virions and virion-associated host proteins, multiple macromolecular complexes were identified. Bioinformatic analysis showed that host chaperones were among over-represented protein families associated with virions, and functional experiments using siRNA gene silencing and small molecule inhibitors identified several of these heat shock proteins, including heat shock protein 90 (HSP90, as important viral host factors. Further analysis indicated that HSP inhibition effects occur during the replication/transcription phase of the virus life cycle, leading to significant lowering of viral titers without compromising the functional capacity of released virions. Overall, these studies provide much needed further insight into interactions between RVFV and host cells, increasing our understanding of the infection process and suggesting novel strategies for anti-viral development. In particular, considering that several HSP90 inhibitors have been advancing through clinical trials for cancer treatment, these results also highlight the exciting potential of repurposing HSP90 inhibitors to treat RVF.

Determination of Vertical Velocity Field of Southernmost Longitudinal Valley in Eastern Taiwan: A Joint Analysis of Leveling and GPS Measurements

Directory of Open Access Journals (Sweden)

Horng-Yue Chen

2012-01-01

Full Text Available In order to provide a detailed vertical velocity field in southernmost Longitudinal Valley where shows a complex three-fault system at the plate suture between Philippine Sea plate and Eurasia, we conducted leveling and GPS measurements, compiled data from previous surveys and combined them into a single data set. We compiled precise leveling results from 1984 to 2009, include 5 E-W trending and one N-S trending routes. We calculated the GPS vertical component from 10 continuous stations and from 89 campaign-mode stations from 1995 to 2010. The interseismic vertical rates are estimated by removing the co- and post-seismic effects of major large regional and nearby earthquakes. A stable continuous station S104 in the study area was adopted as the common reference station. We finally establish a map of the interseismic vertical velocity field. The interseismic vertical deformation was mainly accommodated by creeping/thrusting along two east-dipping strands of the three-fault system: the Luyeh and Lichi faults. The most dominant uplift of 30 mm yr-1 occurs at the hanging wall of the Lichi fault on the western Coastal Range. However the rate diminishes away from the fault in the hanging wall. The Quaternary tablelands inside of the Longitudinal Valley reveals uplift with a rate of 5 - 10 mm yr-1. Outside of the tablelands, the rest of the Longitudinal Valley flat area indicates substantial subsidence of -10 to -20 mm yr-1. Finally, it appears that the west-dipping blind fault under the eastern side of the Central Range does not play a significant role on interseismic deformation with subsidence rate of -5 to -10 mm yr-1.

Single-Molecule FISH Reveals Non-selective Packaging of Rift Valley Fever Virus Genome Segments.

Directory of Open Access Journals (Sweden)

Paul J Wichgers Schreur

2016-08-01

Full Text Available The bunyavirus genome comprises a small (S, medium (M, and large (L RNA segment of negative polarity. Although genome segmentation confers evolutionary advantages by enabling genome reassortment events with related viruses, genome segmentation also complicates genome replication and packaging. Accumulating evidence suggests that genomes of viruses with eight or more genome segments are incorporated into virions by highly selective processes. Remarkably, little is known about the genome packaging process of the tri-segmented bunyaviruses. Here, we evaluated, by single-molecule RNA fluorescence in situ hybridization (FISH, the intracellular spatio-temporal distribution and replication kinetics of the Rift Valley fever virus (RVFV genome and determined the segment composition of mature virions. The results reveal that the RVFV genome segments start to replicate near the site of infection before spreading and replicating throughout the cytoplasm followed by translocation to the virion assembly site at the Golgi network. Despite the average intracellular S, M and L genome segments approached a 1:1:1 ratio, major differences in genome segment ratios were observed among cells. We also observed a significant amount of cells lacking evidence of M-segment replication. Analysis of two-segmented replicons and four-segmented viruses subsequently confirmed the previous notion that Golgi recruitment is mediated by the Gn glycoprotein. The absence of colocalization of the different segments in the cytoplasm and the successful rescue of a tri-segmented variant with a codon shuffled M-segment suggested that inter-segment interactions are unlikely to drive the copackaging of the different segments into a single virion. The latter was confirmed by direct visualization of RNPs inside mature virions which showed that the majority of virions lack one or more genome segments. Altogether, this study suggests that RVFV genome packaging is a non-selective process.

Seroprevalence of Infections with Dengue, Rift Valley Fever and Chikungunya Viruses in Kenya, 2007.

Directory of Open Access Journals (Sweden)

Caroline Ochieng

Full Text Available Arthropod-borne viruses are a major constituent of emerging infectious diseases worldwide, but limited data are available on the prevalence, distribution, and risk factors for transmission in Kenya and East Africa. In this study, we used 1,091 HIV-negative blood specimens from the 2007 Kenya AIDS Indicator Survey (KAIS 2007 to test for the presence of IgG antibodies to dengue virus (DENV, chikungunya virus (CHIKV and Rift Valley fever virus (RVFV.The KAIS 2007 was a national population-based survey conducted by the Government of Kenya to provide comprehensive information needed to address the HIV/AIDS epidemic. Antibody testing for arboviruses was performed on stored blood specimens from KAIS 2007 through a two-step sandwich IgG ELISA using either commercially available kits or CDC-developed assays. Out of the 1,091 samples tested, 210 (19.2% were positive for IgG antibodies against at least one of the three arboviruses. DENV was the most common of the three viruses tested (12.5% positive, followed by RVFV and CHIKV (4.5% and 0.97%, respectively. For DENV and RVFV, the participant's province of residence was significantly associated (P≤.01 with seropositivity. Seroprevalence of DENV and RVFV increased with age, while there was no correlation between province of residence/age and seropositivity for CHIKV. Females had twelve times higher odds of exposure to CHIK as opposed to DENV and RVFV where both males and females had the same odds of exposure. Lack of education was significantly associated with a higher odds of previous infection with either DENV or RVFV (p <0.01. These data show that a number of people are at risk of arbovirus infections depending on their geographic location in Kenya and transmission of these pathogens is greater than previously appreciated. This poses a public health risk, especially for DENV.

Exploratory space-time analyses of Rift Valley Fever in South Africa in 2008-2011.

Directory of Open Access Journals (Sweden)

Raphaëlle Métras

Full Text Available Rift Valley fever (RVF is a zoonotic arbovirosis for which the primary hosts are domestic livestock (cattle, sheep and goats. RVF was first described in South Africa in 1950-1951. Mechanisms for short and long distance transmission have been hypothesised, but there is little supporting evidence. Here we describe RVF occurrence and spatial distribution in South Africa in 2008-11, and investigate the presence of a contagious process in order to generate hypotheses on the different mechanisms of transmission.A total of 658 cases were extracted from World Animal Health Information Database. Descriptive statistics, epidemic curves and maps were produced. The space-time K-function was used to test for evidence of space-time interaction. Five RVF outbreak waves (one in 2008, two in 2009, one in 2010 and one in 2011 of varying duration, location and size were reported. About 70% of cases (n = 471 occurred in 2010, when the epidemic was almost country-wide. No strong evidence of space-time interaction was found for 2008 or the second wave in 2009. In the first wave of 2009, a significant space-time interaction was detected for up to one month and over 40 km. In 2010 and 2011 a significant intense, short and localised space-time interaction (up to 3 days and 15 km was detected, followed by one of lower intensity (up to 2 weeks and 35 to 90 km.The description of the spatiotemporal patterns of RVF in South Africa between 2008 and 2011 supports the hypothesis that during an epidemic, disease spread may be supported by factors other than active vector dispersal. Limitations of under-reporting and space-time K-function properties are discussed. Further spatial analyses and data are required to explain factors and mechanisms driving RVF spread.

[Emerging diseases. Crimean-Congo hemorrhagic fever].

Science.gov (United States)

Kuljić-Kapulica, Nada

2004-01-01

Recognized for many years in central Asia and Eastern Europe, Crimean-Congo hemorrhagic fever (CCHF) is a severe zoonotic disease which affects people coming into contact with livestock or ticks. The range of the CCHF virus is now known to extend form central Asia to India, Pakistan, Afghanistan, Iran, Iraq, the Middle East, Eastern Europe, and to most of Saharan and sub-Saharan Africa. CCHF virus is a member of the Bunyavirus family, and is classified as a Nairovirus. After an incubation period of approximately 3 to 6 days the abrupt onset of acute febrile illness occurs. The first symptoms are similar to severe influenza and include fever, headache, severe back and abdominal pain. The hemorrhagic fever manifestations occur after several days of illnesses and include petechial rash, ecchymoses, hematemmesis, and melenna. Cases typically present with some form of hepatitis. The mortality rate is 10-50% in different outbreaks with deaths typically occurring during the second week of illness. The genus Hyalomma of ixodid ticks is the most important vector of the CCHF virus. Vertebrates including birds and small animals provide excellent amplifier hosts of both the virus and the tick. The virus can be transmitted to humans by direct contact with infected animals and from person to person. Early diagnosis is possible in special laboratories using antigen detection by imunofluorescence or ELISA tests or molecular methods as PCR and antibody detection. Tick control measures need to be emphasized and utilized to prevent CCHF. This includes spraying camp sites, clothing and danger areas with acaricides or repellent. Strict isolation of patients with CCHF and a focus on barrier nursing would help to prevent nosocomial spread. Presently the vaccine is a dangerous mouse brain-derived version. Future development of a vaccine would help to prevent human infection.

TRAINING PROGRAM FOR NURSING STAFF REGARDING VIRAL HEMORRHAGIC FEVERS IN A MILITARY HOSPITAL.

Science.gov (United States)

El-Bahnasawy, Mamdouh M; Megahed, Laila Abdel-Mawla; Saleh, Halla Ahmed Abdullah; Abdelfattah, Magda Abdelhamid; Morsy, Tosson Aly

2015-08-01

Viral hemorrhagic fevers (VHFs) refer to a group of illnesses caused by several distinct families of viruses. In general, the term "viral hemorrhagic fever" is used to describe a severe multisystem syndrome (multisystem in that multiple organ systems in the bpdy are affected). Characteristically, the overall vascular system is damaged, and the body's ability to regulate itself is impaired. These symptoms are often accompanied by hemorrhage (bleeding); however, the bleeding is it rarely life-threatening. While some types of hemorrhagic fever viruses can cause relatively mild illnesses, many of these viruses cause severe, life-threatening disease. The selected disaster diseases for this study included: 1-Crimean-Congo hemorrhagic Fever, 2-Dengue Fever, 3-Ebola Fever, 4-Hem-orrhagic Fever with renal syndrome (HFRS), 5-Hantavirus Pulmonary Syndrome, 6-Lassa Fever, 7-Marburg Fever, 8-Rift Valley Fever and 9-Yellow Fever. The educational training program was given over ten sessions to a group of Staff Nurses. The results showed that the program succeeded in enhancing nurse' knowledge, awareness, responsibility, and obligations toward patients with the Viral Hemorrhagic Fevers The results showed a significant impact of training sessions illuminated in the follow-up test on the knowledge score of nurses in all types of diseases except for the Congo hemorrhagic fever, while, statistical significance varied in some diseases in the study when it comes to the comparison between pretest and post-test. All results confirmed on the positive impact of the training program in enhancing the knowledge of nurses toward VHFs patients and their relevant. There was a significant positive impact of the training sessions on changing the attitude of nurses toward patients with VHFs. This result was confirmed on the collective level since the total scores on tests revealed significant positive impact of the study on changing the attitude of nurses toward relevant patients. The relationship

A ΩXaV motif in the Rift Valley fever virus NSs protein is essential for degrading p62, forming nuclear filaments and virulence.

Science.gov (United States)

Cyr, Normand; de la Fuente, Cynthia; Lecoq, Lauriane; Guendel, Irene; Chabot, Philippe R; Kehn-Hall, Kylene; Omichinski, James G

2015-05-12

Rift Valley fever virus (RVFV) is a single-stranded RNA virus capable of inducing fatal hemorrhagic fever in humans. A key component of RVFV virulence is its ability to form nuclear filaments through interactions between the viral nonstructural protein NSs and the host general transcription factor TFIIH. Here, we identify an interaction between a ΩXaV motif in NSs and the p62 subunit of TFIIH. This motif in NSs is similar to ΩXaV motifs found in nucleotide excision repair (NER) factors and transcription factors known to interact with p62. Structural and biophysical studies demonstrate that NSs binds to p62 in a similar manner as these other factors. Functional studies in RVFV-infected cells show that the ΩXaV motif is required for both nuclear filament formation and degradation of p62. Consistent with the fact that the RVFV can be distinguished from other Bunyaviridae-family viruses due to its ability to form nuclear filaments in infected cells, the motif is absent in the NSs proteins of other Bunyaviridae-family viruses. Taken together, our studies demonstrate that p62 binding to NSs through the ΩXaV motif is essential for degrading p62, forming nuclear filaments and enhancing RVFV virulence. In addition, these results show how the RVFV incorporates a simple motif into the NSs protein that enables it to functionally mimic host cell proteins that bind the p62 subunit of TFIIH.

Therapeutic management of Crimean-Congo haemorrhagic fever.

Science.gov (United States)

de la Calle-Prieto, Fernando; Martín-Quirós, Alejandro; Trigo, Elena; Mora-Rillo, Marta; Arsuaga, Marta; Díaz-Menéndez, Marta; Arribas, José Ramón

2017-06-29

Crimean-Congo haemorrhagic fever has been reported in more than 30 countries in Africa, Asia, the Middle East and Eastern Europe, with an increasing incidence in recent years, especially in Europe. Because no specific treatments have demonstrated efficacy, supportive treatment is essential, as well as the provision of a centre with the appropriate means to guarantee the safety of its healthcare professionals. Laboratory monitoring of thrombocytopenia, severe coagulopathy or liver failure is of critical importance. Patients with Crimean-Congo haemorrhagic fever should be admitted to High Level Isolation Units where appropriate biocontainment procedures can prevent nosocomial transmission through infected fluids or accidents with contaminated material. In case of high-risk exposures, early administration of ribavirin should be considered. Copyright © 2017. Publicado por Elsevier España, S.L.U.

Unravelling recent environmental change in a lowland river valley, eastern Ireland: geoarchaeological applications

Science.gov (United States)

Foster, Gez; Turner, Jonathan

2010-05-01

This paper reports the preliminary findings of an Irish Heritage Council INSTAR funded research project on the geoarchaeology and fluvial geomorphology of the lower River Boyne valley, eastern Ireland. The nature and evolution of the contemporary Boyne floodplain at Dunmoe, Co. Meath (53° 40' 22.8" N, 6° 37' 54.7" W) has been investigated using a multi-technique approach combining field and terrestrial LiDAR-based geomorphological mapping, radiocarbon dating of channel migration activity, electrical resistivity tomography surveys of sub-surface topography and high-resolution X-ray and XRF geochemical characterisation of fine-grained sediment fill sequences. All of these lines of evidence support a tripartite sub-division of the floodplain. Valley marginal floodplain Zone 1 is characterised by a colluvial sediment fill which has buried an irregular ditch-basin-platform surface containing recent archaeological material. Subtle variations in mapped elevation suggest that the buried surface may represent the site of an abandoned river-side complex, possibly a small docking area or port. Geomorphological field relationships suggest that the possible archaeological site was connected to a former bank line position of the main River Boyne (floodplain Zone 2) via a small canal. Radiocarbon dating of Zone 2 channel gravels suggests that the channel associated with this bank position was abandoned some time before 1490-1610 AD. Subsequent vertical and lateral channel migration, the onset of which has been radiocarbon dated to the 17th or 18th century AD, led to the development of the lowest and most recent floodplain surface (Zone 3). The sedimentology and geochemistry of the Zone 2 and 3 fluvial sediment sequences suggests that recent centuries have involved an increase in fluvial flood risk, evidenced by the burial of alluvial soils by bedded, shell-rich sands. A more complete understanding of the timing and environmental drivers of increasing flood risk is anticipated

Tri-phasic fever in dengue fever.

Science.gov (United States)

D, Pradeepa H; Rao, Sathish B; B, Ganaraj; Bhat, Gopalakrishna; M, Chakrapani

2018-04-01

Dengue fever is an acute febrile illness with a duration of 2-12 days. Our observational study observed the 24-h continuous tympanic temperature pattern of 15 patients with dengue fever and compared this with 26 others with fever due to a non-dengue aetiology. A tri-phasic fever pattern was seen among two-thirds of dengue fever patients, but in only one with an inflammatory disease. One-third of dengue fever patients exhibited a single peak temperature. Continuous temperature monitoring and temperature pattern analysis in clinical settings can aid in the early differentiation of dengue fever from non-dengue aetiology.

Safety and Efficacy Profile of Commercial Veterinary Vaccines against Rift Valley Fever: A Review Study

Directory of Open Access Journals (Sweden)

Moataz Alhaj

2016-01-01

Full Text Available Rift Valley Fever (RVF is an infectious illness with serious clinical manifestations and health consequences in humans as well as a wide range of domestic ruminants. This review provides significant information about the prevention options of RVF along with the safety-efficacy profile of commercial vaccines and some of RVF vaccination strategies. Information presented in this paper was obtained through a systematic investigation of published data about RVF vaccines. Like other viral diseases, the prevention of RVF relies heavily on immunization of susceptible herds with safe and cost-effective vaccine that is able to confer long-term protective immunity. Several strains of RVF vaccines have been developed and are available in commercial production including Formalin-Inactivated vaccine, live attenuated Smithburn vaccine, and the most recent Clone13. Although Formalin-Inactivated vaccine and live attenuated Smithburn vaccine are immunogenic and widely used in prevention programs, they proved to be accompanied by significant concerns. Despite Clone13 vaccine being suggested as safe in pregnant ewes and as highly immunogenic along with its potential for differentiating infected from vaccinated animals (DIVA, a recent study raised concerns about the safety of the vaccine during the first trimester of gestation. Accordingly, RVF vaccines that are currently available in the market to a significant extent do not fulfill the requirements of safety, potency, and DIVA. These adverse effects stressed the need for developing new vaccines with an excellent safety profile to bridge the gap in safety and immunity. Bringing RVF vaccine candidates to local markets besides the absence of validated serological test for DIVA remain the major challenges of RVF control.

Current status of Crimean-Congo haemorrhagic fever in the World Health Organization Eastern Mediterranean Region: issues, challenges, and future directions.

Science.gov (United States)

Al-Abri, Seif S; Abaidani, Idris Al; Fazlalipour, Mehdi; Mostafavi, Ehsan; Leblebicioglu, Hakan; Pshenichnaya, Natalia; Memish, Ziad A; Hewson, Roger; Petersen, Eskild; Mala, Peter; Nhu Nguyen, Tran Minh; Rahman Malik, Mamunur; Formenty, Pierre; Jeffries, Rosanna

2017-05-01

Crimean-Congo haemorrhagic fever (CCHF) is the most widespread, tick-borne viral disease affecting humans. The disease is endemic in many regions, such as Africa, Asia, Eastern and Southern Europe, and Central Asia. Recently, the incidence of CCHF has increased rapidly in the countries of the World Health Organization Eastern Mediterranean Region (WHO EMR), with sporadic human cases and outbreaks of CCHF being reported from a number of countries in the region. Despite the rapidly growing incidence of the disease, there are currently no accurate data on the burden of the disease in the region due to the different surveillance systems used for CCHF in these countries. In an effort to increase our understanding of the epidemiology and risk factors for the transmission of the CCHF virus (CCHFV; a Nairovirus of the family Bunyaviridae) in the WHO EMR, and to identify the current knowledge gaps that are hindering effective control interventions, a sub-regional meeting was organized in Muscat, Oman, from December 7 to 9, 2015. This article summarizes the current knowledge of the disease in the region, identifies the knowledge gaps that present challenges for the prevention and control of CCHFV, and details a strategic framework for research and development activities that would be necessary to curb the ongoing and new threats posed by CCHFV. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Current status of Crimean-Congo haemorrhagic fever in the World Health Organization Eastern Mediterranean Region: issues, challenges, and future directions

Directory of Open Access Journals (Sweden)

Seif S. Al-Abri

2017-05-01

Full Text Available Crimean-Congo haemorrhagic fever (CCHF is the most widespread, tick-borne viral disease affecting humans. The disease is endemic in many regions, such as Africa, Asia, Eastern and Southern Europe, and Central Asia. Recently, the incidence of CCHF has increased rapidly in the countries of the World Health Organization Eastern Mediterranean Region (WHO EMR, with sporadic human cases and outbreaks of CCHF being reported from a number of countries in the region. Despite the rapidly growing incidence of the disease, there are currently no accurate data on the burden of the disease in the region due to the different surveillance systems used for CCHF in these countries. In an effort to increase our understanding of the epidemiology and risk factors for the transmission of the CCHF virus (CCHFV; a Nairovirus of the family Bunyaviridae in the WHO EMR, and to identify the current knowledge gaps that are hindering effective control interventions, a sub-regional meeting was organized in Muscat, Oman, from December 7 to 9, 2015. This article summarizes the current knowledge of the disease in the region, identifies the knowledge gaps that present challenges for the prevention and control of CCHFV, and details a strategic framework for research and development activities that would be necessary to curb the ongoing and new threats posed by CCHFV.

Predicting distribution of Aedes aegypti and Culex pipiens complex, potential vectors of Rift Valley fever virus in relation to disease epidemics in East Africa

Directory of Open Access Journals (Sweden)

Clement Nyamunura Mweya

2013-10-01

Full Text Available Background: The East African region has experienced several Rift Valley fever (RVF outbreaks since the 1930s. The objective of this study was to identify distributions of potential disease vectors in relation to disease epidemics. Understanding disease vector potential distributions is a major concern for disease transmission dynamics. Methods: Diverse ecological niche modelling techniques have been developed for this purpose: we present a maximum entropy (Maxent approach for estimating distributions of potential RVF vectors in un-sampled areas in East Africa. We modelled the distribution of two species of mosquitoes (Aedes aegypti and Culex pipiens complex responsible for potential maintenance and amplification of the virus, respectively. Predicted distributions of environmentally suitable areas in East Africa were based on the presence-only occurrence data derived from our entomological study in Ngorongoro District in northern Tanzania. Results: Our model predicted potential suitable areas with high success rates of 90.9% for A. aegypti and 91.6% for C. pipiens complex. Model performance was statistically significantly better than random for both species. Most suitable sites for the two vectors were predicted in central and northwestern Tanzania with previous disease epidemics. Other important risk areas include western Lake Victoria, northern parts of Lake Malawi, and the Rift Valley region of Kenya. Conclusion: Findings from this study show distributions of vectors had biological and epidemiological significance in relation to disease outbreak hotspots, and hence provide guidance for the selection of sampling areas for RVF vectors during inter-epidemic periods.

Predicting distribution of Aedes aegypti and Culex pipiens complex, potential vectors of Rift Valley fever virus in relation to disease epidemics in East Africa.

Science.gov (United States)

Mweya, Clement Nyamunura; Kimera, Sharadhuli Iddi; Kija, John Bukombe; Mboera, Leonard E G

2013-01-01

The East African region has experienced several Rift Valley fever (RVF) outbreaks since the 1930s. The objective of this study was to identify distributions of potential disease vectors in relation to disease epidemics. Understanding disease vector potential distributions is a major concern for disease transmission dynamics. DIVERSE ECOLOGICAL NICHE MODELLING TECHNIQUES HAVE BEEN DEVELOPED FOR THIS PURPOSE: we present a maximum entropy (Maxent) approach for estimating distributions of potential RVF vectors in un-sampled areas in East Africa. We modelled the distribution of two species of mosquitoes (Aedes aegypti and Culex pipiens complex) responsible for potential maintenance and amplification of the virus, respectively. Predicted distributions of environmentally suitable areas in East Africa were based on the presence-only occurrence data derived from our entomological study in Ngorongoro District in northern Tanzania. Our model predicted potential suitable areas with high success rates of 90.9% for A. aegypti and 91.6% for C. pipiens complex. Model performance was statistically significantly better than random for both species. Most suitable sites for the two vectors were predicted in central and northwestern Tanzania with previous disease epidemics. Other important risk areas include western Lake Victoria, northern parts of Lake Malawi, and the Rift Valley region of Kenya. Findings from this study show distributions of vectors had biological and epidemiological significance in relation to disease outbreak hotspots, and hence provide guidance for the selection of sampling areas for RVF vectors during inter-epidemic periods.

First case of yellow fever vaccine-associated viscerotropic disease (YEL-AVD) in Hong Kong.

Science.gov (United States)

Leung, Wai Shing; Chan, Man Chun; Chik, Shiu Hong; Tsang, Tak Yin

2016-04-01

Yellow fever is an important and potentially fatal infection in tropical regions of Africa, South America, eastern Panama in Central America and Trinidad in the Caribbean. Yellow fever vaccination is not only crucial to reduce the disease risk and mortality in individuals travelling to these areas, but also an important public health measure to prevent the spread of the disease. Despite generally considered as a safe vaccine, yellow fever vaccine can rarely be associated with severe adverse reactions including yellow fever vaccine-associated viscerotropic disease (YEL-AVD). Here, we report the first case of YEL-AVD in Hong Kong. Clinicians should alert to the possibility of YEL-AVD in vaccinees presenting with compatible symptoms after yellow fever vaccination, particularly in people at higher risk of adverse events. © International Society of Travel Medicine, 2016. All rights reserved. Published by Oxford University Press. For permissions, please e-mail: journals.permissions@oup.com.

Detection and identification of Rift Valley fever virus in mosquito vectors by quantitative real-time PCR.

Science.gov (United States)

Mwaengo, D; Lorenzo, G; Iglesias, J; Warigia, M; Sang, R; Bishop, R P; Brun, A

2012-10-01

Diagnostic methods allowing for rapid identification of pathogens are crucial for controlling and preventing dissemination after disease outbreaks as well as for use in surveillance programs. For arboviruses, detection of the presence of virus in their arthropod hosts is important for monitoring of viral activity and quantitative information is useful for modeling of transmission dynamics. In this study, molecular detection of Rift Valley fever virus (RVFV) in mosquito samples from the 2006 to 2007 East African outbreaks was performed using quantitative real-time PCR assay (qRT-PCR). Specific RVFV sequence-based primer/fluorogenic (TaqMan) probe sets were derived from the L and S RNA segments of the virus. Both primer-probe L and S segment-based combinations detected genomic RVFV sequences, with generally comparable levels of sensitivity. Viral loads from three mosquito species, Aedes mcintoshi, Aedes ochraceus and Mansonia uniformis were estimated and significant differences of between 5- and 1000-fold were detected between Ae. mcintoshi and M. uniformis using both the L and S primer-probe-based assays. The genetic relationships of the viral sequences in mosquito samples were established by partial M segment sequencing and assigned to the two previously described viral lineages defined by analysis of livestock isolates obtained during the 2006-2007 outbreak, confirming that similar viruses were present in both the vector and mammalian host. The data confirms the utility of qRT-PCR for identification and initial quantification of virus in mosquito samples during RVFV outbreaks. Copyright © 2012 Elsevier B.V. All rights reserved.

Experimental transmission of West Nile Virus and Rift Valley Fever Virus by Culex pipiens from Lebanon.

Directory of Open Access Journals (Sweden)

Renée Zakhia

2018-01-01

Full Text Available West Nile virus (WNV and Rift Valley fever virus (RVFV are two emerging arboviruses transmitted by Culex pipiens species that includes two biotypes: pipiens and molestus. In Lebanon, human cases caused by WNV and RVFV have never been reported. However, the introduction of these viruses in the country is likely to occur through the migratory birds and animal trades. In this study, we evaluated the ability of Cx. pipiens, a predominant mosquito species in urban and rural regions in Lebanon, to transmit WNV and RVFV. Culex egg rafts were collected in the West Bekaa district, east of Lebanon and adult females of Cx. pipiens were experimentally infected with WNV and RVFV Clone 13 strain at titers of 1.6×108 and 1.33×107 plaque forming units (PFU/mL, respectively. We estimated viral infection, dissemination and transmission at 3, 7, 14 and 19 days post infection (dpi. Results showed that infection was higher for WNV than for RVFV from 3 dpi to 19 dpi. Viral dissemination and transmission started from 3 dpi for WNV; and only from 19 dpi for RVFV. Moreover, Cx. pipiens were able to excrete in saliva a higher number of viral particles of WNV (1028 ± 405 PFU/saliva at 19 dpi than RVFV (42 PFU/saliva at 19 dpi. Cx. pipiens from Lebanon are efficient experimental vectors of WNV and to a lower extent, RVFV. These findings should stimulate local authorities to establish an active entomological surveillance in addition to animal surveys for both viruses in the country.

Seroprevalence of Brucellosis, Leptospirosis, and Q Fever among Butchers and Slaughterhouse Workers in South-Eastern Iran.

Science.gov (United States)

Esmaeili, Saber; Naddaf, Saied Reza; Pourhossein, Behzad; Hashemi Shahraki, Abdolrazagh; Bagheri Amiri, Fahimeh; Gouya, Mohammad Mehdi; Mostafavi, Ehsan

2016-01-01

Zoonotic diseases can be occupational hazards to people who work in close contact with animals or their carcasses. In this cross-sectional study, 190 sera were collected from butchers and slaughterhouse workers in different regions of the Sistan va Baluchestan province, in Iran in 2011. A questionnaire was filled for each participant to document personal and behavioural information. The sera were tested for detection of specific IgG antibodies against brucellosis, leptospirosis, and Q fever (phase I and II) using commercial enzyme-linked immunosorbent assays (ELISA). The seroprevalence of brucellosis was 7.9%, leptospirosis 23.4%, and phase I and II of Q fever were 18.1% and 14.4%, respectively. The seroprevalence of Q fever and leptospirosis, but not brucellosis, varied among regions within the province (p = 0.01). Additionally, a significant relationship was found between seropositivity of Q fever and camel slaughtering (p = 0.04). Reduced seropositivity rate of brucellosis was associated with use of personal protective equipment (PPE) (p = 0.004). This study shows that brucellosis, leptospirosis and Q fever occur among butchers and slaughterhouse workers in this area.

Wetlands, wild Bovidae species richness and sheep density delineate risk of Rift Valley fever outbreaks in the African continent and Arabian Peninsula.

Directory of Open Access Journals (Sweden)

Michael G Walsh

2017-07-01

Full Text Available Rift Valley fever (RVF is an emerging, vector-borne viral zoonosis that has significantly impacted public health, livestock health and production, and food security over the last three decades across large regions of the African continent and the Arabian Peninsula. The potential for expansion of RVF outbreaks within and beyond the range of previous occurrence is unknown. Despite many large national and international epidemics, the landscape epidemiology of RVF remains obscure, particularly with respect to the ecological roles of wildlife reservoirs and surface water features. The current investigation modeled RVF risk throughout Africa and the Arabian Peninsula as a function of a suite of biotic and abiotic landscape features using machine learning methods. Intermittent wetland, wild Bovidae species richness and sheep density were associated with increased landscape suitability to RVF outbreaks. These results suggest the role of wildlife hosts and distinct hydrogeographic landscapes in RVF virus circulation and subsequent outbreaks may be underestimated. These results await validation by studies employing a deeper, field-based interrogation of potential wildlife hosts within high risk taxa.

Rift Valley fever in a zone potentially occupied by Aedes vexans in Senegal: dynamics and risk mapping

Directory of Open Access Journals (Sweden)

Cécile Vignolles

2009-05-01

Full Text Available This paper presents an analysis of the interaction between the various variables associated with Rift Valley fever (RVF such as the mosquito vector, available hosts and rainfall distribution. To that end, the varying zones potentially occupied by mosquitoes (ZPOM, rainfall events and pond dynamics, and the associated exposure of hosts to the RVF virus by Aedes vexans, were analyzed in the Barkedji area of the Ferlo, Senegal, during the 2003 rainy season. Ponds were identified by remote sensing using a high-resolution SPOT-5 satellite image. Additional data on ponds and rainfall events from the Tropical Rainfall Measuring Mission were combined with in-situ entomological and limnimetric measurements, and the localization of vulnerable ruminant hosts (data derived from QuickBird satellite. Since “Ae. vexans productive events” are dependent on the timing of rainfall for their embryogenesis (six days without rain are necessary to trigger hatching, the dynamic spatio-temporal distribution of Ae. vexans density was based on the total rainfall amount and pond dynamics. Detailed ZPOM mapping was obtained on a daily basis and combined with aggressiveness temporal profiles. Risks zones, i.e. zones where hazards and vulnerability are combined, are expressed by the percentages of parks where animals are potentially exposed to mosquito bites. This new approach, simply relying upon rainfall distribution evaluated from space, is meant to contribute to the implementation of a new, operational early warning system for RVF based on environmental risks linked to climatic and environmental conditions.

NSs Protein of Rift Valley Fever Virus Promotes Posttranslational Downregulation of the TFIIH Subunit p62▿

Science.gov (United States)

Kalveram, Birte; Lihoradova, Olga; Ikegami, Tetsuro

2011-01-01

Rift Valley fever virus (RVFV; family Bunyaviridae, genus Phlebovirus) is an important emerging pathogen of humans and ruminants. Its NSs protein has previously been identified as a major virulence factor that suppresses host defense through three distinct mechanisms: it directly inhibits beta interferon (IFN-β) promoter activity, it promotes the degradation of double-stranded RNA-dependent protein kinase (PKR), and it suppresses host transcription by disrupting the assembly of the basal transcription factor TFIIH through sequestration of its p44 subunit. Here, we report that in addition to PKR, NSs also promotes the degradation of the TFIIH subunit p62. Infection of cells with the RVFV MP-12 vaccine strain reduced p62 protein levels to below the detection limit early in the course of infection. This NSs-mediated downregulation of p62 was posttranslational, as it was unaffected by pharmacological inhibition of transcription or translation and MP-12 infection had no effect on p62 mRNA levels. Treatment of cells with proteasome inhibitors but not inhibition of lysosomal acidification or nuclear export resulted in a stabilization of p62 in the presence of NSs. Furthermore, p62 could be coprecipitated with NSs from lysates of infected cells. These data suggest that the RVFV NSs protein is able to interact with the TFIIH subunit p62 inside infected cells and promotes its degradation, which can occur directly in the nucleus. PMID:21543505

A temperature-limited assessment of the risk of Rift Valley fever transmission and establishment in the continental United States of America

Directory of Open Access Journals (Sweden)

Sarah K. Konrad

2012-05-01

Full Text Available The rapid spread of West Nile virus across North America after its introduction in 1999 highlights the potential for foreign arboviruses to become established in the United States of America. Of particular concern is Rift Valley fever virus (RVFV, which has been responsible for multiple African epidemics resulting in death of both humans and livestock, as well as major economic disruption due to livestock loss and trade restrictions. Modern globalization, travel, and commerce allow viruses to easily jump from one continent to another; and it is likely only a matter of time before RVFV reaches North American shores. We used a degree-day model in combination with livestock population data and a pathways analysis to identify regions and times where RVFV is most likely to enter and become established in the United States of America. Transmission risk of the disease varies across the country from 325 annual risk days in parts of Florida to zero risk days in the far North and in high mountain regions. Areas of particular concern are where there are a high number of possible transmission days, a large livestock population, and proximity to likely locations for the disease to enter the country via mosquito vector or human host. These areas should be monitored closely during transmission “risk seasons” so that if the virus does enter the country and begins to become established, it can be quickly controlled and eliminated before spreading further. Areas most at risk include the Baltimore and New York City metro areas as well as much of the region between these urban centers; most of Texas, especially around Houston; Florida; Atlanta; southwest Nebraska; southern California and Arizona; and the central valley of California.

Seroprevalence of Brucellosis, Leptospirosis, and Q Fever among Butchers and Slaughterhouse Workers in South-Eastern Iran.

Directory of Open Access Journals (Sweden)

Saber Esmaeili

Full Text Available Zoonotic diseases can be occupational hazards to people who work in close contact with animals or their carcasses. In this cross-sectional study, 190 sera were collected from butchers and slaughterhouse workers in different regions of the Sistan va Baluchestan province, in Iran in 2011. A questionnaire was filled for each participant to document personal and behavioural information. The sera were tested for detection of specific IgG antibodies against brucellosis, leptospirosis, and Q fever (phase I and II using commercial enzyme-linked immunosorbent assays (ELISA. The seroprevalence of brucellosis was 7.9%, leptospirosis 23.4%, and phase I and II of Q fever were 18.1% and 14.4%, respectively. The seroprevalence of Q fever and leptospirosis, but not brucellosis, varied among regions within the province (p = 0.01. Additionally, a significant relationship was found between seropositivity of Q fever and camel slaughtering (p = 0.04. Reduced seropositivity rate of brucellosis was associated with use of personal protective equipment (PPE (p = 0.004. This study shows that brucellosis, leptospirosis and Q fever occur among butchers and slaughterhouse workers in this area.

Genetic Evidence for an Interferon-Antagonistic Function of Rift Valley Fever Virus Nonstructural Protein NSs

Science.gov (United States)

Bouloy, Michèle; Janzen, Christian; Vialat, Pierre; Khun, Huot; Pavlovic, Jovan; Huerre, Michel; Haller, Otto

2001-01-01

Rift Valley fever virus (RVFV), a phlebovirus of the family Bunyaviridae, is a major public health threat in Egypt and sub-Saharan Africa. The viral and host cellular factors that contribute to RVFV virulence and pathogenicity are still poorly understood. All pathogenic RVFV strains direct the synthesis of a nonstructural phosphoprotein (NSs) that is encoded by the smallest (S) segment of the tripartite genome and has an undefined accessory function. In this report, we show that MP12 and clone 13, two attenuated RVFV strains with mutations in the NSs gene, were highly virulent in IFNAR−/− mice lacking the alpha/beta interferon (IFN-α/β) receptor but remained attenuated in IFN-γ receptor-deficient mice. Both attenuated strains proved to be excellent inducers of early IFN-α/β production. In contrast, the virulent strain ZH548 failed to induce detectable amounts of IFN-α/β and replicated extensively in both IFN-competent and IFN-deficient mice. Clone 13 has a defective NSs gene with a large in-frame deletion. This defect in the NSs gene results in expression of a truncated protein which is rapidly degraded. To investigate whether the presence of the wild-type NSs gene correlated with inhibition of IFN-α/β production, we infected susceptible IFNAR−/− mice with S gene reassortant viruses. When the S segment of ZH548 was replaced by that of clone 13, the resulting reassortants became strong IFN inducers. When the defective S segment of clone 13 was exchanged with the wild-type S segment of ZH548, the reassortant virus lost the capacity to stimulate IFN-α/β production. These results demonstrate that the ability of RVFV to inhibit IFN-α/β production correlates with viral virulence and suggest that the accessory protein NSs is an IFN antagonist. PMID:11152510

The use of Nanotrap particles in the enhanced detection of Rift Valley fever virus nucleoprotein.

Directory of Open Access Journals (Sweden)

Nazly Shafagati

Full Text Available Rift Valley fever virus (RVFV is a highly pathogenic arthropod-borne virus that has a detrimental effect on both livestock and human populations. While there are several diagnostic methodologies available for RVFV detection, many are not sensitive enough to diagnose early infections. Furthermore, detection may be hindered by high abundant proteins such as albumin. Previous findings have shown that Nanotrap particles can be used to significantly enhance detection of various small analytes of low abundance. We have expanded upon this repertoire to show that this simple and efficient sample preparation technology can drastically improve the detection of the RVFV nucleoprotein (NP, the most abundant and widely used viral protein for RVFV diagnostics.After screening multiple Nanotrap particle architectures, we found that one particle, NT45, was optimal for RVFV NP capture, as demonstrated by western blotting. NT45 significantly enhanced detection of the NP at levels undetectable without the technology. Importantly, we demonstrated that Nanotrap particles are capable of concentrating NP in a number of matrices, including infected cell lysates, viral supernatants, and animal sera. Specifically, NT45 enhanced detection of NP at various viral titers, multiplicity of infections, and time points. Our most dramatic results were observed in spiked serum samples, where high abundance serum proteins hindered detection of NP without Nanotrap particles. Nanotrap particles allowed for sample cleanup and subsequent detection of RVFV NP. Finally, we demonstrated that incubation of our samples with Nanotrap particles protects the NP from degradation over extended periods of time (up to 120 hours and at elevated temperatures (at 37ºC.This study demonstrates that Nanotrap particles are capable of drastically lowering the limit of detection for RVFV NP by capturing, concentrating, and preserving RVFV NP in clinically relevant matrices. These studies can be extended to

Laboratory safe detection of nucleocapsid protein of Rift Valley fever virus in human and animal specimens by a sandwich ELISA.

Science.gov (United States)

Jansen van Vuren, P; Paweska, J T

2009-04-01

A safe laboratory procedure, based on a sandwich ELISA (sAg-ELISA), was developed and evaluated for the detection of nucleocapsid protein (NP) of Rift Valley fever virus (RVFV) in specimens inactivated at 56 degrees C for 1h in the presence of 0.5% Tween-20 (v/v) before testing. Polyclonal capture and detection immune sera were generated respectively in sheep and rabbits immunized with recombinant NP antigen. The assay was highly repeatable and specific; it detected strains of RVFV from the entire distributional range of the disease, isolated over a period of 53 years; no cross-reactivity with genetically related African phleboviruses or other members of the family Bunyaviridae was observed. In specimens spiked with RVFV, including human and animal sera, homogenates of liver and spleen tissues of domestic ruminants, and Anopheles mosquito homogenates, the sAg-ELISA detection limit ranged from log(10)10(2.2) to 10(3.2) TCID(50)/reaction volume. The ELISA detected NP antigen in spiked bovine and sheep liver homogenates up to at least 8 days of incubation at 37 degrees C whereas infectious virus could not be detected at 48h incubation in these adverse conditions. Compared to virus isolation from sera from RVF patients and sheep infected experimentally, the ELISA had 67.7% and 70% sensitivity, and 97.97% and 100% specificity, respectively. The assay was 100% accurate when testing tissues of various organs from mice infected experimentally and buffalo foetuses infected naturally. The assay was able to detect NP antigen in infective culture supernatants 16-24h before cytopathic effects were observed microscopically and as early as 8h after inoculation with 10(5.8) TCID(50)/ml of RVFV. This ability renders the assay for rapid identification of the virus when its primary isolation is attempted in vitro. As a highly specific, safe and simple assay format, the sAg-ELISA represents a valuable diagnostic tool for use in less equipped laboratories in Africa, and for routine

Co-housing of Rift Valley fever virus infected lambs with immunocompetent or immunosuppressed lambs does not result in virus transmission

Directory of Open Access Journals (Sweden)

Paul J Wichgers Schreur

2016-03-01

Full Text Available Rift Valley fever virus (RVFV is transmitted among susceptible animals by mosquito vectors. Although the virus can be isolated from nasal and oral swabs of infected animals and is known to be highly infectious when administered experimentally via oral or respiratory route, horizontal transmission of the virus is only sporadically reported in literature. We considered that immunosuppression resulting from stressful conditions in the field may increase the susceptibility to horizontally transmitted RVFV. Additionally, we reasoned that horizontal transmission may induce immune responses that could affect the susceptibility of contact-exposed animals to subsequent infection via mosquito vectors. To address these two hypotheses, viremic lambs were brought into contact with sentinel lambs. One group of sentinel lambs was treated with the immunosuppressive synthetic glucocorticosteroid dexamethasone and monitored for signs of disease and presence of virus in the blood and target organs. Another group of contact-exposed sentinel lambs remained untreated for three weeks and was subsequently challenged with RVFV. We found that none of the dexamethasone-treated contact-exposed lambs developed detectable viremia, antibody responses or significant increases in cytokine mRNA levels. Susceptibility of immunocompetent lambs to RVFV infection was not influenced by previous contact-exposure. Our results are discussed in light of previous findings.

[Microbiological surveillance: viral hemorrhagic fever in Central African Republic: current serological data in man].

Science.gov (United States)

Nakounné, E; Selekon, B; Morvan, J

2000-01-01

An investigation was conducted between 1994 and 1997 in forested areas of the Central African Republic (CAR) to determine the seroprevalence of IgG antibodies against several haemorrhagic fever viruses present in the region. Sera were obtained from 1762 individuals in two groups (Pygmy and Bantu locuted populations) living in 4 forested areas in the south of the country. Sera were tested for IgG antibodies against Ebola, Marburg, Rift Valley fever (RVF), Yellow fever (YF) and Hantaviruses by enzyme immunoassay (EIA), and against Lassa virus by immunofluorescent assay. The prevalence of IgG antibodies was 5.9% for Ebola, 2% for Marburg, 6.9% pour RVF, 6.5% for YF, 2% for Hantaan. No antibodies were detected against Lassa, Seoul, Puumala and Thottapalayam viruses. No IgM antibodies were detected against RVF and YF viruses. The distribution of antibodies appears to be related to tropical rain forest areas. This study indicates that several haemorrhagic fever viruses are endemic in forested areas of the CAR and could emerge due to environmental modification.

Modelling the effects of seasonality and socioeconomic impact on the transmission of Rift Valley fever virus

Science.gov (United States)

Xiao, Yanyu; Beier, John C.; Cantrell, Robert Stephen; Cosner, Chris; DeAngelis, Donald L.; Ruan, Shigui

2015-01-01

Rift Valley fever (RVF) is an important mosquito-borne viral zoonosis in Africa and the Middle East that causes human deaths and significant economic losses due to huge incidences of death and abortion among infected livestock. Outbreaks of RVF are sporadic and associated with both seasonal and socioeconomic effects. Here we propose an almost periodic three-patch model to investigate the transmission dynamics of RVF virus (RVFV) among ruminants with spatial movements. Our findings indicate that, in Northeastern Africa, human activities, including those associated with the Eid al Adha feast, along with a combination of climatic factors such as rainfall level and hydrological variations, contribute to the transmission and dispersal of the disease pathogen. Moreover, sporadic outbreaks may occur when the two events occur together: 1) abundant livestock are recruited into areas at risk from RVF due to the demand for the religious festival and 2) abundant numbers of mosquitoes emerge. These two factors have been shown to have impacts on the severity of RVF outbreaks. Our numerical results present the transmission dynamics of the disease pathogen over both short and long periods of time, particularly during the festival time. Further, we investigate the impact on patterns of disease outbreaks in each patch brought by festival- and seasonal-driven factors, such as the number of livestock imported daily, the animal transportation speed from patch to patch, and the death rate induced by ceremonial sacrifices. In addition, our simulations show that when the time for festival preparation starts earlier than usual, the risk of massive disease outbreaks rises, particularly in patch 3 (the place where the religious ceremony will be held).

Crustal deformation rates in Assam Valley, Shillong Plateau, Eastern Himalaya, and Indo-Burmese region from 11 years (2002-2013) of GPS measurements

Science.gov (United States)

Barman, Prakash; Jade, Sridevi; Shrungeshwara, T. S.; Kumar, Ashok; Bhattacharyya, Sanjeev; Ray, Jagat Dwipendra; Jagannathan, Saigeetha; Jamir, Wangshi Menla

2017-09-01

The present study reports the contemporary deformation of the tectonically complex northeast India using 11 years (2002-2013) of GPS observations. The central Shillong Plateau and few sites north of Plateau located in Assam Valley behave like a rigid block with 7 mm/year India-fixed southward velocity. The Euler pole of rotation of this central Shillong Plateau-Assam Valley (SH-AS) block is estimated to be at -25.1° ± 0.2°N, -97.8° ± 1.8°E with an angular velocity of 0.533° ± 0.10° Myr-1 relative to India-fixed reference frame. Kopili fault located between Shillong Plateau and Mikir massif records a dextral slip of 4.7 ± 1.3 mm/year with a locking depth of 10.2 ± 1.4 km indicating the fragmentation of Assam Valley across the fault. Presently, western edge of Mikir massif appears to be locked to Assam block indicating strain accumulation in this region. First-order elastic dislocation modelling of the GPS velocities estimates a slip rate of 16 mm/year along the Main Himalayan Thrust in Eastern Himalaya which is locked over a width of 130 km from the surface to a depth of 17 km with underthrusting Indian plate. Around 9 mm/year arc-normal convergence is accommodated in Lesser Himalaya just south of Main Central Thrust indicating high strain accumulation. Out of 36 mm/year (SSE) India-Sunda plate motion, about 16 mm/year motion is accommodated in Indo-Burmese Fold and Thrust Belt, both as normal convergence ( 6 mm/year) and active slip ( 7-11 mm/year) in this region.

TerraSAR-X high-resolution radar remote sensing: an operational warning system for Rift Valley fever risk.

Science.gov (United States)

Vignolles, Cécile; Tourre, Yves M; Mora, Oscar; Imanache, Laurent; Lafaye, Murielle

2010-11-01

In the vicinity of the Barkedji village (in the Ferlo region of Senegal), the abundance and aggressiveness of the vector mosquitoes for Rift Valley fever (RVF) are strongly linked to rainfall events and associated ponds dynamics. Initially, these results were obtained from spectral analysis of high-resolution (~10 m) Spot-5 images, but, as a part of the French AdaptFVR project, identification of the free water dynamics within ponds was made with the new high-resolution (down to 3-meter pixels), Synthetic Aperture Radar satellite (TerraSAR-X) produced by Infoterra GmbH, Friedrichshafen/Potsdam, Germany. During summer 2008, within a 30 x 50 km radar image, it was found that identified free water fell well within the footprints of ponds localized by optical data (i.e. Spot-5 images), which increased the confidence in this new and complementary remote sensing technique. Moreover, by using near real-time rainfall data from the Tropical Rainfall Measuring Mission (TRMM), NASA/JAXA joint mission, the filling-up and flushing-out rates of the ponds can be accurately determined. The latter allows for a precise, spatio-temporal mapping of the zones potentially occupied by mosquitoes capable of revealing the variability of pond surfaces. The risk for RVF infection of gathered bovines and small ruminants (~1 park/km(2)) can thus be assessed. This new operational approach (which is independent of weather conditions) is an important development in the mapping of risk components (i.e. hazards plus vulnerability) related to RVF transmission during the summer monsoon, thus contributing to a RVF early warning system.

Predicting Rift Valley Fever Inter-epidemic Activities and Outbreak Patterns: Insights from a Stochastic Host-Vector Model.

Directory of Open Access Journals (Sweden)

Sansao A Pedro

2016-12-01

Full Text Available Rift Valley fever (RVF outbreaks are recurrent, occurring at irregular intervals of up to 15 years at least in East Africa. Between outbreaks disease inter-epidemic activities exist and occur at low levels and are maintained by female Aedes mcintoshi mosquitoes which transmit the virus to their eggs leading to disease persistence during unfavourable seasons. Here we formulate and analyse a full stochastic host-vector model with two routes of transmission: vertical and horizontal. By applying branching process theory we establish novel relationships between the basic reproduction number, R0, vertical transmission and the invasion and extinction probabilities. Optimum climatic conditions and presence of mosquitoes have not fully explained the irregular oscillatory behaviour of RVF outbreaks. Using our model without seasonality and applying van Kampen system-size expansion techniques, we provide an analytical expression for the spectrum of stochastic fluctuations, revealing how outbreaks multi-year periodicity varies with the vertical transmission. Our theory predicts complex fluctuations with a dominant period of 1 to 10 years which essentially depends on the efficiency of vertical transmission. Our predictions are then compared to temporal patterns of disease outbreaks in Tanzania, Kenya and South Africa. Our analyses show that interaction between nonlinearity, stochasticity and vertical transmission provides a simple but plausible explanation for the irregular oscillatory nature of RVF outbreaks. Therefore, we argue that while rainfall might be the major determinant for the onset and switch-off of an outbreak, the occurrence of a particular outbreak is also a result of a build up phenomena that is correlated to vertical transmission efficiency.

TerraSAR-X high-resolution radar remote sensing: an operational warning system for Rift Valley fever risk

Directory of Open Access Journals (Sweden)

Cécile Vignolles

2010-11-01

Full Text Available In the vicinity of the Barkedji village (in the Ferlo region of Senegal, the abundance and aggressiveness of the vector mosquitoes for Rift Valley fever (RVF are strongly linked to rainfall events and associated ponds dynamics. Initially, these results were obtained from spectral analysis of high-resolution (~10 m Spot-5 images, but, as a part of the French AdaptFVR project, identification of the free water dynamics within ponds was made with the new high-resolution (down to 3-meter pixels, Synthetic Aperture Radar satellite (TerraSAR-X produced by Infoterra GmbH, Friedrichshafen/Potsdam, Germany. During summer 2008, within a 30 x 50 km radar image, it was found that identified free water fell well within the footprints of ponds localized by optical data (i.e. Spot-5 images, which increased the confidence in this new and complementary remote sensing technique. Moreover, by using near real-time rainfall data from the Tropical Rainfall Measuring Mission (TRMM, NASA/JAXA joint mission, the filling-up and flushingout rates of the ponds can be accurately determined. The latter allows for a precise, spatio-temporal mapping of the zones potentially occupied by mosquitoes capable of revealing the variability of pond surfaces. The risk for RVF infection of gathered bovines and small ruminants (~1 park/km2 can thus be assessed. This new operational approach (which is independent of weather conditions is an important development in the mapping of risk components (i.e. hazards plus vulnerability related to RVF transmission during the summer monsoon, thus contributing to a RVF early warning system.

Rift valley fever virus nonstructural protein NSs promotes viral RNA replication and transcription in a minigenome system.

Science.gov (United States)

Ikegami, Tetsuro; Peters, C J; Makino, Shinji

2005-05-01

Rift Valley fever virus (RVFV), which belongs to the genus Phlebovirus, family Bunyaviridae, has a tripartite negative-strand genome (S, M, and L segments) and is an important mosquito-borne pathogen for domestic animals and humans. We established an RVFV T7 RNA polymerase-driven minigenome system in which T7 RNA polymerase from an expression plasmid drove expression of RNA transcripts for viral proteins and minigenome RNA transcripts carrying a reporter gene between both termini of the M RNA segment in 293T cells. Like other viruses of the Bunyaviridae family, replication and transcription of the RVFV minigenome required expression of viral N and L proteins. Unexpectedly, the coexpression of an RVFV nonstructural protein, NSs, with N and L proteins resulted in a significant enhancement of minigenome RNA replication. Coexpression of NSs protein with N and L proteins also enhanced minigenome mRNA transcription in the cells expressing viral-sense minigenome RNA transcripts. NSs protein expression increased the RNA replication of minigenomes that originated from S and L RNA segments. Enhancement of minigenome RNA synthesis by NSs protein occurred in cells lacking alpha/beta interferon (IFN-alpha/beta) genes, indicating that the effect of NSs protein on minigenome RNA replication was unrelated to a putative NSs protein-induced inhibition of IFN-alpha/beta production. Our finding that RVFV NSs protein augmented minigenome RNA synthesis was in sharp contrast to reports that Bunyamwera virus (genus Bunyavirus) NSs protein inhibits viral minigenome RNA synthesis, suggesting that RVFV NSs protein and Bunyamwera virus NSs protein have distinctly different biological roles in viral RNA synthesis.

Combining hydrology and mosquito population models to identify the drivers of Rift Valley fever emergence in semi-arid regions of West Africa.

Science.gov (United States)

Soti, Valérie; Tran, Annelise; Degenne, Pascal; Chevalier, Véronique; Lo Seen, Danny; Thiongane, Yaya; Diallo, Mawlouth; Guégan, Jean-François; Fontenille, Didier

2012-01-01

Rift Valley fever (RVF) is a vector-borne viral zoonosis of increasing global importance. RVF virus (RVFV) is transmitted either through exposure to infected animals or through bites from different species of infected mosquitoes, mainly of Aedes and Culex genera. These mosquitoes are very sensitive to environmental conditions, which may determine their presence, biology, and abundance. In East Africa, RVF outbreaks are known to be closely associated with heavy rainfall events, unlike in the semi-arid regions of West Africa where the drivers of RVF emergence remain poorly understood. The assumed importance of temporary ponds and rainfall temporal distribution therefore needs to be investigated. A hydrological model is combined with a mosquito population model to predict the abundance of the two main mosquito species (Aedes vexans and Culex poicilipes) involved in RVFV transmission in Senegal. The study area is an agropastoral zone located in the Ferlo Valley, characterized by a dense network of temporary water ponds which constitute mosquito breeding sites. The hydrological model uses daily rainfall as input to simulate variations of pond surface areas. The mosquito population model is mechanistic, considers both aquatic and adult stages and is driven by pond dynamics. Once validated using hydrological and entomological field data, the model was used to simulate the abundance dynamics of the two mosquito species over a 43-year period (1961-2003). We analysed the predicted dynamics of mosquito populations with regards to the years of main outbreaks. The results showed that the main RVF outbreaks occurred during years with simultaneous high abundances of both species. Our study provides for the first time a mechanistic insight on RVFV transmission in West Africa. It highlights the complementary roles of Aedes vexans and Culex poicilipes mosquitoes in virus transmission, and recommends the identification of rainfall patterns favourable for RVFV amplification.

Combining hydrology and mosquito population models to identify the drivers of Rift Valley fever emergence in semi-arid regions of West Africa.

Directory of Open Access Journals (Sweden)

Valérie Soti

Full Text Available BACKGROUND: Rift Valley fever (RVF is a vector-borne viral zoonosis of increasing global importance. RVF virus (RVFV is transmitted either through exposure to infected animals or through bites from different species of infected mosquitoes, mainly of Aedes and Culex genera. These mosquitoes are very sensitive to environmental conditions, which may determine their presence, biology, and abundance. In East Africa, RVF outbreaks are known to be closely associated with heavy rainfall events, unlike in the semi-arid regions of West Africa where the drivers of RVF emergence remain poorly understood. The assumed importance of temporary ponds and rainfall temporal distribution therefore needs to be investigated. METHODOLOGY/PRINCIPAL FINDINGS: A hydrological model is combined with a mosquito population model to predict the abundance of the two main mosquito species (Aedes vexans and Culex poicilipes involved in RVFV transmission in Senegal. The study area is an agropastoral zone located in the Ferlo Valley, characterized by a dense network of temporary water ponds which constitute mosquito breeding sites. The hydrological model uses daily rainfall as input to simulate variations of pond surface areas. The mosquito population model is mechanistic, considers both aquatic and adult stages and is driven by pond dynamics. Once validated using hydrological and entomological field data, the model was used to simulate the abundance dynamics of the two mosquito species over a 43-year period (1961-2003. We analysed the predicted dynamics of mosquito populations with regards to the years of main outbreaks. The results showed that the main RVF outbreaks occurred during years with simultaneous high abundances of both species. CONCLUSION/SIGNIFICANCE: Our study provides for the first time a mechanistic insight on RVFV transmission in West Africa. It highlights the complementary roles of Aedes vexans and Culex poicilipes mosquitoes in virus transmission, and recommends

Rift Valley fever dynamics in Senegal: a project for pro-active adaptation and improvement of livestock raising management

Directory of Open Access Journals (Sweden)

Murielle Lafaye

2013-11-01

Full Text Available The multi-disciplinary French project “Adaptation à la Fièvre de la Vallée du Rift” (AdaptFVR has concluded a 10-year constructive interaction between many scientists/partners involved with the Rift Valley fever (RVF dynamics in Senegal. The three targeted objectives reached were (i to produce - in near real-time - validated risk maps for parked livestock exposed to RVF mosquitoes/vectors bites; (ii to assess the impacts on RVF vectors from climate variability at different time-scales including climate change; and (iii to isolate processes improving local livestock management and animal health. Based on these results, concrete, pro-active adaptive actions were taken on site, which led to the establishment of a RVF early warning system (RVFews. Bulletins were released in a timely fashion during the project, tested and validated in close collaboration with the local populations, i.e. the primary users. Among the strategic, adaptive methods developed, conducted and evaluated in terms of cost/benefit analyses are the larvicide campaigns and the coupled bio-mathematical (hydrological and entomological model technologies, which are being transferred to the staff of the “Centre de Suivi Ecologique” (CSE in Dakar during 2013. Based on the results from the AdaptFVR project, other projects with similar conceptual and modelling approaches are currently being implemented, e.g. for urban and rural malaria and dengue in the French Antilles.

Non-fatal case of Crimean-Congo haemorrhagic fever imported into the United Kingdom (ex Bulgaria), June 2014.

Science.gov (United States)

Lumley, S; Atkinson, B; Dowall, Sd; Pitman, Jk; Staplehurst, S; Busuttil, J; Simpson, Aj; Aarons, Ej; Petridou, C; Nijjar, M; Glover, S; Brooks, Tj; Hewson, R

2014-07-31

Crimean-Congo haemorrhagic fever (CCHF) was diagnosed in a United Kingdom traveller who returned from Bulgaria in June 2014. The patient developed a moderately severe disease including fever, headaches and petechial rash. CCHF was diagnosed following identification of CCHF virus (CCHFV) RNA in a serum sample taken five days after symptom onset. Sequence analysis of the CCHFV genome showed that the virus clusters within the Europe 1 clade, which includes viruses from eastern Europe.

A Multiplex PCR/LDR Assay for the Simultaneous Identification of Category A Infectious Pathogens: Agents of Viral Hemorrhagic Fever and Variola Virus.

Directory of Open Access Journals (Sweden)

Sanchita Das

Full Text Available CDC designated category A infectious agents pose a major risk to national security and require special action for public health preparedness. They include viruses that cause viral hemorrhagic fever (VHF syndrome as well as variola virus, the agent of smallpox. VHF is characterized by hemorrhage and fever with multi-organ failure leading to high morbidity and mortality. Smallpox, a prior scourge, has been eradicated for decades, making it a particularly serious threat if released nefariously in the essentially non-immune world population. Early detection of the causative agents, and the ability to distinguish them from other pathogens, is essential to contain outbreaks, implement proper control measures, and prevent morbidity and mortality. We have developed a multiplex detection assay that uses several species-specific PCR primers to generate amplicons from multiple pathogens; these are then targeted in a ligase detection reaction (LDR. The resultant fluorescently-labeled ligation products are detected on a universal array enabling simultaneous identification of the pathogens. The assay was evaluated on 32 different isolates associated with VHF (ebolavirus, marburgvirus, Crimean Congo hemorrhagic fever virus, Lassa fever virus, Rift Valley fever virus, Dengue virus, and Yellow fever virus as well as variola virus and vaccinia virus (the agent of smallpox and its vaccine strain, respectively. The assay was able to detect all viruses tested, including 8 sequences representative of different variola virus strains from the CDC repository. It does not cross react with other emerging zoonoses such as monkeypox virus or cowpox virus, or six flaviviruses tested (St. Louis encephalitis virus, Murray Valley encephalitis virus, Powassan virus, Tick-borne encephalitis virus, West Nile virus and Japanese encephalitis virus.

A Multiplex PCR/LDR Assay for the Simultaneous Identification of Category A Infectious Pathogens: Agents of Viral Hemorrhagic Fever and Variola Virus.

Science.gov (United States)

Das, Sanchita; Rundell, Mark S; Mirza, Aashiq H; Pingle, Maneesh R; Shigyo, Kristi; Garrison, Aura R; Paragas, Jason; Smith, Scott K; Olson, Victoria A; Larone, Davise H; Spitzer, Eric D; Barany, Francis; Golightly, Linnie M

2015-01-01

CDC designated category A infectious agents pose a major risk to national security and require special action for public health preparedness. They include viruses that cause viral hemorrhagic fever (VHF) syndrome as well as variola virus, the agent of smallpox. VHF is characterized by hemorrhage and fever with multi-organ failure leading to high morbidity and mortality. Smallpox, a prior scourge, has been eradicated for decades, making it a particularly serious threat if released nefariously in the essentially non-immune world population. Early detection of the causative agents, and the ability to distinguish them from other pathogens, is essential to contain outbreaks, implement proper control measures, and prevent morbidity and mortality. We have developed a multiplex detection assay that uses several species-specific PCR primers to generate amplicons from multiple pathogens; these are then targeted in a ligase detection reaction (LDR). The resultant fluorescently-labeled ligation products are detected on a universal array enabling simultaneous identification of the pathogens. The assay was evaluated on 32 different isolates associated with VHF (ebolavirus, marburgvirus, Crimean Congo hemorrhagic fever virus, Lassa fever virus, Rift Valley fever virus, Dengue virus, and Yellow fever virus) as well as variola virus and vaccinia virus (the agent of smallpox and its vaccine strain, respectively). The assay was able to detect all viruses tested, including 8 sequences representative of different variola virus strains from the CDC repository. It does not cross react with other emerging zoonoses such as monkeypox virus or cowpox virus, or six flaviviruses tested (St. Louis encephalitis virus, Murray Valley encephalitis virus, Powassan virus, Tick-borne encephalitis virus, West Nile virus and Japanese encephalitis virus).

Implications of ammonia emissions for fine aerosol formation and visibility impairment. A case study from the Lower Fraser Valley, British Columbia

DEFF Research Database (Denmark)

Barthelmie, R.J.; Pryor, S.C.

1998-01-01

of nitrogen and sulphur oxides over agricultural areas in the eastern and central valley with higher ammonia emissions favours subsequent ammonium nitrate and sulphate formation. This leads to higher fine mass concentrations and lowest visibility in the predominantly agricultural regions of the valley. (C...

Historical trajectories and restoration strategies for the Mississippi River alluvial valley

Science.gov (United States)

Brice B. Hanberry; John M. Kabrick; Hong S. He; Brian J. Palik

2012-01-01

Unlike upland forests in the eastern United States, little research is available about the composition and structure of bottomland forests before Euro-American settlement. To provide a historical reference encompassing spatial variation for the Lower Mississippi River Alluvial Valley, we quantified forest types, species distributions, densities, and stocking of...

Early to Middle Holocene sea level fluctuation, coastal progradation and the Neolithic occupation in the Yaojiang Valley of southern Hangzhou Bay, Eastern China

Science.gov (United States)

Liu, Yan; Sun, Qianli; Fan, Daidu; Dai, Bin; Ma, Fuwei; Xu, Lichen; Chen, Jing; Chen, Zhongyuan

2018-06-01

The Yaojiang Valley (YJV) of southern Hangzhou Bay was the birthplace of the well-known Hemudu Culture (HC), one of the representatives of Neolithic civilization in eastern China. To explore the magnitude of natural environmental effects on the HC trajectory, the palaeo-embayment setting of the YJV was studied in detail for the first time in terms of 3D Holocene strata supported by a series of new radiocarbon-dated cores. The results indicated that the local relative sea level rose rapidly during the Early Holocene in the YJV, reached its maximum flooding surface ca. 7900 cal yr BP, and then remained stable ca. 7900-7600 cal yr BP. Thereupon, an estuary stretching inland was first formed by marine transgression, and then, it was transformed to an alluvial-coastal plain by regressive progradation. The alluvial plain was initiated in the foothills and then spread towards the valley centre after sea level stabilization ca. 7600 cal yr BP. Accompanying these natural environmental changes, the earliest arrivals of foragers in the valley occurred no later than ca. 7000 cal yr BP. They engaged in rice farming and fostered the HC for approximately two millennia from ca. 7000-5000 cal yr BP as more lands developed from coastal progradation. The rise and development of the HC are closely associated with the sea level-induced landscape changes in the YJV in the Early-Middle Holocene, but the enigmatic exodus of the HC people after ca. 5000 cal yr BP is still contentious and possibly linked with the rapid waterlogging and deterioration of this setting in such a low-lying coastal plain as well as with associated social reasons.

Crimean-Congo Hemorrhagic Fever

Directory of Open Access Journals (Sweden)

Emadi Koochak H

2003-10-01

Full Text Available Crimean-Congo hemorrhagic fever (CCHF was first described in the Crimea in 1944 and then in 1956 in congo. CCHF is a viral hemorrhagic fever of the Nairovirus group that belongs to Bunyaviridae family virus. It is transmitted to human by tick bite. The most efficient and common tick that is the vectors of CCHF is a member of the Hyalomma genus which infected many mammals such as livestock, this tick is the main reservoire of virus in nature. Humans also become infected with CCHF virus by direct contact with blood or other infected tissues from livestock or human patients (nosocomial infection. Disease has been found in saharic Africa, Eastern Europe, Pakistan, India and Middle East (specially Iran and Iraq. This disease recently spread in Iran so in 1999 to 2001 at least 222 suspected case(81 definite case reported that led to the death of 15 of 81 cases. It is estimated that 30 percent of the country's cattle are contaminated with this virus."nIn humans, after a short incubation period it appears suddenly with fever, chills, myalgia and GI symptoms followed by severe bleeding and DIC that led to death .If the patient improved, has a long {2-4 weeks convalescence period. Disease diagnosed by clinical manifestations, serologic tests, viral culture and PCR and its specific treatment is oral ribavirin for 10 days, for prevention of disease personal protective measures from tick bite, spraying poison of mews to reduce of ticks crowd, isolation of patients and dis-infection of contaminated personal equipments that who suffering from CCHF is recommended.

Yellow Fever

Science.gov (United States)

... Testing Vaccine Information Testing for Vaccine Adverse Events Yellow fever Vaccine Continuing Education Course Yellow Fever Home Prevention Vaccine Vaccine Recommendations Reactions to Yellow Fever Vacine Yellow Fever Vaccine, Pregnancy, & ... Transmission Symptoms, Diagnosis, & Treatment Maps Africa ...

Structural evolution of the east Sierra Valley system (Owens Valley and vicinity), California: a geologic and geophysical synthesis

Science.gov (United States)

Stevens, Calvin H.; Stone, Paul; Blakely, Richard J.

2013-01-01

The tectonically active East Sierra Valley System (ESVS), which comprises the westernmost part of the Walker Lane-Eastern California Shear Zone, marks the boundary between the highly extended Basin and Range Province and the largely coherent Sierra Nevada-Great Valley microplate (SN-GVm), which is moving relatively NW. The recent history of the ESVS is characterized by oblique extension partitioned between NNW-striking normal and strike-slip faults oriented at an angle to the more northwesterly relative motion of the SN-GVm. Spatially variable extension and right-lateral shear have resulted in a longitudinally segmented valley system composed of diverse geomorphic and structural elements, including a discontinuous series of deep basins detected through analysis of isostatic gravity anomalies. Extension in the ESVS probably began in the middle Miocene in response to initial westward movement of the SN-GVm relative to the Colorado Plateau. At ca. 3-3.5 Ma, the SN-GVm became structurally separated from blocks directly to the east, resulting in significant basin-forming deformation in the ESVS. We propose a structural model that links high-angle normal faulting in the ESVS with coeval low-angle detachment faulting in adjacent areas to the east.

Distribution and abundance of key vectors of Rift Valley fever and other arboviruses in two ecologically distinct counties in Kenya.

Directory of Open Access Journals (Sweden)

Rosemary Sang

2017-02-01

Full Text Available Rift Valley fever (RVF is a mosquito-borne viral zoonosis of ruminants and humans that causes outbreaks in Africa and the Arabian Peninsula with significant public health and economic consequences. Humans become infected through mosquito bites and contact with infected livestock. The virus is maintained between outbreaks through vertically infected eggs of the primary vectors of Aedes species which emerge following rains with extensive flooding. Infected female mosquitoes initiate transmission among nearby animals, which amplifies virus, thereby infecting more mosquitoes and moving the virus beyond the initial point of emergence. With each successive outbreak, RVF has been found to expand its geographic distribution to new areas, possibly driven by available vectors. The aim of the present study was to determine if RVF virus (RVFV transmission risk in two different ecological zones in Kenya could be assessed by looking at the species composition, abundance and distribution of key primary and secondary vector species and the level of virus activity.Mosquitoes were trapped during short and long rainy seasons in 2014 and 2015 using CO2 baited CDC light traps in two counties which differ in RVF epidemic risk levels(high risk Tana-River and low risk Isiolo,cryo-preserved in liquid nitrogen, transported to the laboratory, and identified to species. Mosquito pools were analyzed for virus infection using cell culture screening and molecular analysis.Over 69,000 mosquitoes were sampled and identified as 40 different species belonging to 6 genera (Aedes, Anopheles, Mansonia, Culex, Aedeomyia, Coquillettidia. The presence and abundance of Aedes mcintoshi and Aedes ochraceus, the primary mosquito vectors associated with RVFV transmission in outbreaks, varied significantly between Tana-River and Isiolo. Ae. mcintoshi was abundant in Tana-River and Isiolo but notably, Aedes ochraceus found in relatively high numbers in Tana-River (n = 1,290, was totally

Epidemiological characteristics of Brazilian spotted fever in Minas Gerais State, Brazil, 2000-2008

Directory of Open Access Journals (Sweden)

Frederico Figueiredo Amâncio

2011-10-01

Full Text Available Brazilian spotted fever is the most common rickettsiosis in Brazil, most prevalent in the States of São Paulo and Minas Gerais. The aim of this study was to describe the epidemiological characteristics of Brazilian spotted fever in Minas Gerais from 2000 to 2008. Of the 132 cases of Brazilian spotted fever, 53 patients died, representing a case-fatality rate of 40.2%. Males predominated, with 78.8% of confirmed cases, and median age was 26.5 years. Absence of rash was associated with increased risk of death (p = 0.005. Greater Metropolitan Belo Horizonte, Rio Doce Valley, and Zona da Mata accounted for 70.6% of the cases, which occurred mainly from May to November. There was an increase in the number of cases, which could suggest an expansion of the disease, but probably resulted from an increase in the health system's diagnostic capacity and sensitivity. Despite this improvement, the case-fatality rate remains high and with no apparent tendency to decrease, thus indicating the need for improved prevention and patient care.

Fever

Directory of Open Access Journals (Sweden)

Tamas Bartfai

2010-01-01

Full Text Available Measurement of body temperature remains one of the most common ways to assess health. An increase in temperature above what is considered to be a normal value is inevitably regarded as a sure sign of disease and referred to with one simple word: fever. In this review, we summarize how research on fever allowed the identification of the exogenous and endogenous molecules and pathways mediating the fever response. We also show how temperature elevation is common to different pathologies and how the molecular components of the fever-generation pathway represent drug targets for antipyretics, such as acetylsalicylic acid, the first “blockbuster drug”. We also show how fever research provided new insights into temperature and energy homeostasis, and into treatment of infection and inflammation.

Transmission of Rift Valley fever virus from European-breed lambs to Culex pipiens mosquitoes.

Directory of Open Access Journals (Sweden)

Rianka P M Vloet

2017-12-01

Full Text Available Rift Valley fever virus (RVFV is a mosquito-borne bunyavirus of the genus Phlebovirus that is highly pathogenic to ruminants and humans. The disease is currently confined to Africa and the Arabian Peninsula, but globalization and climate change may facilitate introductions of the virus into currently unaffected areas via infected animals or mosquitoes. The consequences of such an introduction will depend on environmental factors, the availability of susceptible ruminants and the capacity of local mosquitoes to transmit the virus. We have previously demonstrated that lambs native to the Netherlands are highly susceptible to RVFV and we here report the vector competence of Culex (Cx. pipiens, the most abundant and widespread mosquito species in the country. Vector competence was first determined after artificial blood feeding of laboratory-reared mosquitoes using the attenuated Clone 13 strain. Subsequently, experiments with wild-type RVFV and mosquitoes hatched from field-collected eggs were performed. Finally, the transmission of RVFV from viremic lambs to mosquitoes was studied.Artificial feeding experiments using Clone 13 demonstrated that indigenous, laboratory-reared Cx. pipiens mosquitoes are susceptible to RVFV and that the virus can be transmitted via their saliva. Experiments with wild-type RVFV and mosquitoes hatched from field-collected eggs confirmed the vector competence of Cx. pipiens mosquitoes from the Netherlands. To subsequently investigate transmission of the virus under more natural conditions, mosquitoes were allowed to feed on RVFV-infected lambs during the viremic period. We found that RVFV is efficiently transmitted from lambs to mosquitoes, although transmission was restricted to peak viremia. Interestingly, in the mosquito-exposed skin samples, replication of RVFV was detected in previously unrecognized target cells.We here report the vector competence of Cx. pipiens mosquitoes from the Netherlands for RVFV. Both

Chemotactic and inflammatory responses in the liver and brain are associated with pathogenesis of Rift Valley fever virus infection in the mouse.

Directory of Open Access Journals (Sweden)

Kimberly K Gray

Full Text Available Rift Valley fever virus (RVFV is a major human and animal pathogen associated with severe disease including hemorrhagic fever or encephalitis. RVFV is endemic to parts of Africa and the Arabian Peninsula, but there is significant concern regarding its introduction into non-endemic regions and the potentially devastating effect to livestock populations with concurrent infections of humans. To date, there is little detailed data directly comparing the host response to infection with wild-type or vaccine strains of RVFV and correlation with viral pathogenesis. Here we characterized clinical and systemic immune responses to infection with wild-type strain ZH501 or IND vaccine strain MP-12 in the C57BL/6 mouse. Animals infected with live-attenuated MP-12 survived productive viral infection with little evidence of clinical disease and minimal cytokine response in evaluated tissues. In contrast, ZH501 infection was lethal, caused depletion of lymphocytes and platelets and elicited a strong, systemic cytokine response which correlated with high virus titers and significant tissue pathology. Lymphopenia and platelet depletion were indicators of disease onset with indications of lymphocyte recovery correlating with increases in G-CSF production. RVFV is hepatotropic and in these studies significant clinical and histological data supported these findings; however, significant evidence of a pro-inflammatory response in the liver was not apparent. Rather, viral infection resulted in a chemokine response indicating infiltration of immunoreactive cells, such as neutrophils, which was supported by histological data. In brains of ZH501 infected mice, a significant chemokine and pro-inflammatory cytokine response was evident, but with little pathology indicating meningoencephalitis. These data suggest that RVFV pathogenesis in mice is associated with a loss of liver function due to liver necrosis and hepatitis yet the long-term course of disease for those that

Biochemical and biophysical characterization of cell-free synthesized Rift Valley fever virus nucleoprotein capsids enables in vitro screening to identify novel antivirals.

Science.gov (United States)

Broce, Sean; Hensley, Lisa; Sato, Tomoharu; Lehrer-Graiwer, Joshua; Essrich, Christian; Edwards, Katie J; Pajda, Jacqueline; Davis, Christopher J; Bhadresh, Rami; Hurt, Clarence R; Freeman, Beverly; Lingappa, Vishwanath R; Kelleher, Colm A; Karpuj, Marcela V

2016-05-14

Viral capsid assembly involves the oligomerization of the capsid nucleoprotein (NP), which is an essential step in viral replication and may represent a potential antiviral target. An in vitro transcription-translation reaction using a wheat germ (WG) extract in combination with a sandwich ELISA assay has recently been used to identify small molecules with antiviral activity against the rabies virus. Here, we examined the application of this system to viruses with capsids with a different structure, such as the Rift Valley fever virus (RVFV), the etiological agent of a severe emerging infectious disease. The biochemical and immunological characterization of the in vitro-generated RVFV NP assembly products enabled the distinction between intermediately and highly ordered capsid structures. This distinction was used to establish a screening method for the identification of potential antiviral drugs for RVFV countermeasures. These results indicated that this unique analytical system, which combines nucleoprotein oligomerization with the specific immune recognition of a highly ordered capsid structure, can be extended to various viral families and used both to study the early stages of NP assembly and to assist in the identification of potential antiviral drugs in a cost-efficient manner. Reviewed by Jeffry Skolnick and Noah Isakov. For the full reviews please go to the Reviewers' comments section.

Role of Culex and Anopheles mosquito species as potential vectors of rift valley fever virus in Sudan outbreak, 2007

Directory of Open Access Journals (Sweden)

Galal Fatma H

2010-03-01

Full Text Available Abstract Background Rift Valley fever (RVF is an acute febrile arthropod-borne viral disease of man and animals caused by a member of the Phlebovirus genus, one of the five genera in the family Bunyaviridae. RVF virus (RVFV is transmitted between animals and human by mosquitoes, particularly those belonging to the Culex, Anopheles and Aedes genera. Methods Experiments were designed during RVF outbreak, 2007 in Sudan to provide an answer about many raised questions about the estimated role of vector in RVFV epidemiology. During this study, adult and immature mosquito species were collected from Khartoum and White Nile states, identified and species abundance was calculated. All samples were frozen individually for further virus detection. Total RNA was extracted from individual insects and RVF virus was detected from Culex, Anopheles and Aedes species using RT-PCR. In addition, data were collected about human cases up to November 24th, 2007 to asses the situation of the disease in affected states. Furthermore, a historical background of the RVF outbreaks was discussed in relation to global climatic anomalies and incriminated vector species. Results A total of 978 mosquitoes, belonging to 3 genera and 7 species, were collected during Sudan outbreak, 2007. Anopheles gambiae arabiensis was the most frequent species (80.7% in White Nile state. Meanwhile, Cx. pipiens complex was the most abundant species (91.2% in Khartoum state. RT-PCR was used and successfully amplified 551 bp within the M segment of the tripartite negative-sense single stranded RNA genome of RVFV. The virus was detected in female, male and larval stages of Culex and Anopheles species. The most affected human age interval was 15-29 years old followed by ≥ 45 years old, 30-44 years old, and then 5-14 years old. Regarding to the profession, housewives followed by farmers, students, shepherd, workers and the free were more vulnerable to the infection. Furthermore, connection between

Validation of an ELISA for the concurrent detection of total antibodies (IgM and IgG to Rift Valley fever virus

Directory of Open Access Journals (Sweden)

Charlotte E. Ellis

2014-05-01

Full Text Available Rift Valley fever virus (RVFV infects humans and livestock, causing haemorrhaging andabortions in animals. Three major RVF epizootics have occurred in South Africa since the1950s and the outbreak in 2010 had a mortality rate of 10.7% in humans. Accurate and earlydetection is therefore essential for management of this zoonotic disease. Enzyme-linkedimmunosorbent assays (ELISAs have been developed for the detection of either IgM or IgGantibodies to RVFV in animal sera. In this study, data are presented on the validation of adouble-antigen ELISA for the simultaneous detection of both classes of antibodies to RVFV ina single test. ELISA plates were coated with a recombinant nucleoprotein. The nucleoprotein,conjugated to horseradish peroxidase, was used as the detecting reagent. A total of 534 serafrom sheep and cattle were used in the validation. The sheep sera were collected during a RVFpathogenesis study at the Agricultural Research Council (ARC – Onderstepoort VeterinaryInstitute and the cattle sera were collected during an outbreak of RVF in 2008 at the ARC –Animal Production Institute in Irene, Pretoria. The ELISA had a diagnostic sensitivity of 98.4%and a specificity of 100% when compared to a commercial cELISA. This convenient and fastassay is suitable for use in serological surveys or monitoring immune responses in vaccinatedanimals.

Development and characterization of a Rift Valley fever virus cell-cell fusion assay using alphavirus replicon vectors

International Nuclear Information System (INIS)

Filone, Claire Marie; Heise, Mark; Doms, Robert W.; Bertolotti-Ciarlet, Andrea

2006-01-01

Rift Valley fever virus (RVFV), a member of the Phlebovirus genus in the Bunyaviridae family, is transmitted by mosquitoes and infects both humans and domestic animals, particularly cattle and sheep. Since primary RVFV strains must be handled in BSL-3+ or BSL-4 facilities, a RVFV cell-cell fusion assay will facilitate the investigation of RVFV glycoprotein function under BSL-2 conditions. As for other members of the Bunyaviridae family, RVFV glycoproteins are targeted to the Golgi, where the virus buds, and are not efficiently delivered to the cell surface. However, overexpression of RVFV glycoproteins using an alphavirus replicon vector resulted in the expression of the glycoproteins on the surface of multiple cell types. Brief treatment of RVFV glycoprotein expressing cells with mildly acidic media (pH 6.2 and below) resulted in rapid and efficient syncytia formation, which we quantified by β-galactosidase α-complementation. Fusion was observed with several cell types, suggesting that the receptor(s) for RVFV is widely expressed or that this acid-dependent virus does not require a specific receptor to mediate cell-cell fusion. Fusion occurred over a broad temperature range, as expected for a virus with both mosquito and mammalian hosts. In contrast to cell fusion mediated by the VSV-G glycoprotein, RVFV glycoprotein-dependent cell fusion could be prevented by treating target cells with trypsin, indicating that one or more proteins (or protein-associated carbohydrate) on the host cell surface are needed to support membrane fusion. The cell-cell fusion assay reported here will make it possible to study the membrane fusion activity of RVFV glycoproteins in a high-throughput format and to screen small molecule inhibitors for the ability to block virus-specific membrane fusion

Identifying landscape features associated with Rift Valley fever virus transmission, Ferlo region, Senegal, using very high spatial resolution satellite imagery.

Science.gov (United States)

Soti, Valérie; Chevalier, Véronique; Maura, Jonathan; Bégué, Agnès; Lelong, Camille; Lancelot, Renaud; Thiongane, Yaya; Tran, Annelise

2013-03-01

Dynamics of most of vector-borne diseases are strongly linked to global and local environmental changes. Landscape changes are indicators of human activities or natural processes that are likely to modify the ecology of the diseases. Here, a landscape approach developed at a local scale is proposed for extracting mosquito favourable biotopes, and for testing ecological parameters when identifying risk areas of Rift Valley fever (RVF) transmission. The study was carried out around Barkedji village, Ferlo region, Senegal. In order to test whether pond characteristics may influence the density and the dispersal behaviour of RVF vectors, and thus the spatial variation in RVFV transmission, we used a very high spatial resolution remote sensing image (2.4 m resolution) provided by the Quickbird sensor to produce a detailed land-cover map of the study area. Based on knowledge of vector and disease ecology, seven landscape attributes were defined at the pond level and computed from the land-cover map. Then, the relationships between landscape attributes and RVF serologic incidence rates in small ruminants were analyzed through a beta-binomial regression. Finally, the best statistical model according to the Akaike Information Criterion corrected for small samples (AICC), was used to map areas at risk for RVF. Among the derived landscape variables, the vegetation density index (VDI) computed within a 500 m buffer around ponds was positively correlated with serologic incidence (premote sensing data for identifying environmental risk factors and mapping RVF risk areas at a local scale.

Simulation modelling of population dynamics of mosquito vectors for rift valley Fever virus in a disease epidemic setting.

Directory of Open Access Journals (Sweden)

Clement N Mweya

Full Text Available Rift Valley Fever (RVF is weather dependent arboviral infection of livestock and humans. Population dynamics of mosquito vectors is associated with disease epidemics. In our study, we use daily temperature and rainfall as model inputs to simulate dynamics of mosquito vectors population in relation to disease epidemics.Time-varying distributed delays (TVDD and multi-way functional response equations were implemented to simulate mosquito vectors and hosts developmental stages and to establish interactions between stages and phases of mosquito vectors in relation to vertebrate hosts for infection introduction in compartmental phases. An open-source modelling platforms, Universal Simulator and Qt integrated development environment were used to develop models in C++ programming language. Developed models include source codes for mosquito fecundity, host fecundity, water level, mosquito infection, host infection, interactions, and egg time. Extensible Markup Language (XML files were used as recipes to integrate source codes in Qt creator with Universal Simulator plug-in. We observed that Floodwater Aedines and Culicine population continued to fluctuate with temperature and water level over simulation period while controlled by availability of host for blood feeding. Infection in the system was introduced by floodwater Aedines. Culicines pick infection from infected host once to amplify disease epidemic. Simulated mosquito population show sudden unusual increase between December 1997 and January 1998 a similar period when RVF outbreak occurred in Ngorongoro district.Findings presented here provide new opportunities for weather-driven RVF epidemic simulation modelling. This is an ideal approach for understanding disease transmission dynamics towards epidemics prediction, prevention and control. This approach can be used as an alternative source for generation of calibrated RVF epidemics data in different settings.

Simulation modelling of population dynamics of mosquito vectors for rift valley Fever virus in a disease epidemic setting.

Science.gov (United States)

Mweya, Clement N; Holst, Niels; Mboera, Leonard E G; Kimera, Sharadhuli I

2014-01-01

Rift Valley Fever (RVF) is weather dependent arboviral infection of livestock and humans. Population dynamics of mosquito vectors is associated with disease epidemics. In our study, we use daily temperature and rainfall as model inputs to simulate dynamics of mosquito vectors population in relation to disease epidemics. Time-varying distributed delays (TVDD) and multi-way functional response equations were implemented to simulate mosquito vectors and hosts developmental stages and to establish interactions between stages and phases of mosquito vectors in relation to vertebrate hosts for infection introduction in compartmental phases. An open-source modelling platforms, Universal Simulator and Qt integrated development environment were used to develop models in C++ programming language. Developed models include source codes for mosquito fecundity, host fecundity, water level, mosquito infection, host infection, interactions, and egg time. Extensible Markup Language (XML) files were used as recipes to integrate source codes in Qt creator with Universal Simulator plug-in. We observed that Floodwater Aedines and Culicine population continued to fluctuate with temperature and water level over simulation period while controlled by availability of host for blood feeding. Infection in the system was introduced by floodwater Aedines. Culicines pick infection from infected host once to amplify disease epidemic. Simulated mosquito population show sudden unusual increase between December 1997 and January 1998 a similar period when RVF outbreak occurred in Ngorongoro district. Findings presented here provide new opportunities for weather-driven RVF epidemic simulation modelling. This is an ideal approach for understanding disease transmission dynamics towards epidemics prediction, prevention and control. This approach can be used as an alternative source for generation of calibrated RVF epidemics data in different settings.

Serological evidence of Rift Valley fever virus circulation in sheep and goats in Zambézia Province, Mozambique.

Directory of Open Access Journals (Sweden)

José Fafetine

Full Text Available Rift Valley fever (RVF is endemic in most parts of Africa and has also been reported to occur in the Arabian Peninsula. It is responsible for significant morbidity and mortality, particularly in livestock, but also in humans. During the last two decades several outbreaks of RVF have been reported in countries in Southern Africa. In contrast to other countries, no clinical disease has been reported in Mozambique during this period. In a serological study conducted in 2007 in five districts of Zambézia Province, Mozambique, of a total of 654 small ruminants sampled (277 sheep and 377 goats, 35.8% of sheep sera and 21.2% of goat sera were positive for RVF virus (RVFV antibodies in a virus neutralization test (VN and in an IgG enzyme-linked immunosorbent assay (ELISA. In 2010, a cross-sectional survey was conducted in 313 sheep and 449 goats in two districts of the same province. This study revealed an overall seropositivity rate of 9.2% in sheep and 11.6% in goat and an increased likelihood of being seropositive in older animals (OR = 7.3; p<0.001 using an IgG ELISA. 29 out of 240 animals assessed for RVF specific IgM by ELISA were positive, suggesting recent exposure to RVFV. However, a longitudinal study carried out between September 2010 and April 2011 in a cohort of 125 of these animals (74 sheep and 51 goats failed to demonstrate seroconversion. The results of the study indicate that RVFV circulates sub-clinically in domestic small ruminants in Zambézia Province.

Arthropod-borne viral infections associated with a fever outbreak in the northern province of Sudan.

Science.gov (United States)

Watts, D M; el-Tigani, A; Botros, B A; Salib, A W; Olson, J G; McCarthy, M; Ksiazek, T G

1994-08-01

An outbreak of acute febrile illness occurred during August and September 1989 in the Northern Province of Sudan coinciding with a high population density of phlebotomine sandflies. An investigation was conducted to determine whether arboviruses were associated with human illness during this outbreak. Sera were obtained from 185 febrile individuals and tested for IgG and IgM antibody to selected arboviruses by enzyme immunoassay (EIA). The prevalence of IgG antibody was 59% for West Nile (WN), 53% for Sandfly Fever Sicilian (SFS), 32% for Sandfly Fever Naples (SFN), 39% for Yellow Fever (YF), 24% for dengue-2 (DEN-2), 23% for Rift Valley Fever (RVF), 12% for Chikungunya (CHIK) and 5% for Crimean-Congo haemorrhagic Fever (CCHF) viruses. Antibody prevalences tended to increase with age for WN and YF viruses. Antibody rates were about the same for males and females for most of the viruses tested. The prevalence of IgM antibody to SFN was 24% and reciprocal IgM titre exceeded 12,800 for some individuals suggesting that this virus was the cause of recent infection. The prevalence of IgM antibody for the other viruses did not exceed 5%. The study indicated that several arboviruses were endemic and some of them may have caused human disease in the Northern Province of Sudan.

Water-quality data from ground- and surface-water sites near concentrated animal feeding operations (CAFOs) and non-CAFOs in the Shenandoah Valley and eastern shore of Virginia, January-February, 2004

Science.gov (United States)

Rice, Karen C.; Monti, Michele M.; Ettinger, Matthew R.

2005-01-01

Concentrated animal feeding operations (CAFOs) result from the consolidation of small farms with animals into larger operations, leading to a higher density of animals per unit of land on CAFOs than on small farms. The density of animals and subsequent concentration of animal wastes potentially can cause contamination of nearby ground and surface waters. This report summarizes water-quality data collected from agricultural sites in the Shenandoah Valley and Eastern Shore of Virginia. Five sites, three non-CAFO and two dairy-operation CAFO sites, were sampled in the Shenandoah Valley. Four sites, one non-CAFO and three poultry-operation CAFO sites were sampled on the Eastern Shore. All samples were collected during January and February 2004. Water samples were analyzed for the following parameters and constituents: temperature, specific conductance, pH, and dissolved oxygen; concentrations of the indicator organisms Escherichia coli (E. coli) and enterococci; bacterial isolates of E. coli, enterococci, Salmonella spp., and Campylobacter spp.; sensitivity to antibiotics of E. coli, enterococci, and Salmonella spp.; arsenic, cadmium, chromium3+, copper, nickel, and mercury; hardness, biological oxygen demand, nitrate, nitrite, ammonia, ortho-phosphate, total Kjeldahl nitrogen, chemical oxygen demand, total organic carbon, and dissolved organic carbon; and 45 dissolved organic compounds, which included a suite of antibiotic compounds.Data are presented in tables 5-21 and results of analyses of replicate samples are presented in tables 22-28. A summary of the data in tables 5-8 and 18-21 is included in the report.

Structural Evolution of the East Sierra Valley System (Owens Valley and Vicinity, California: A Geologic and Geophysical Synthesis

Directory of Open Access Journals (Sweden)

Richard J. Blakely

2013-04-01

Full Text Available The tectonically active East Sierra Valley System (ESVS, which comprises the westernmost part of the Walker Lane-Eastern California Shear Zone, marks the boundary between the highly extended Basin and Range Province and the largely coherent Sierra Nevada-Great Valley microplate (SN-GVm, which is moving relatively NW. The recent history of the ESVS is characterized by oblique extension partitioned between NNW-striking normal and strike-slip faults oriented at an angle to the more northwesterly relative motion of the SN-GVm. Spatially variable extension and right-lateral shear have resulted in a longitudinally segmented valley system composed of diverse geomorphic and structural elements, including a discontinuous series of deep basins detected through analysis of isostatic gravity anomalies. Extension in the ESVS probably began in the middle Miocene in response to initial westward movement of the SN-GVm relative to the Colorado Plateau. At ca. 3–3.5 Ma, the SN-GVm became structurally separated from blocks directly to the east, resulting in significant basin-forming deformation in the ESVS. We propose a structural model that links high-angle normal faulting in the ESVS with coeval low-angle detachment faulting in adjacent areas to the east.

Identifying Areas Suitable for the Occurrence of Rift Valley Fever in North Africa: Implications for Surveillance.

Science.gov (United States)

Arsevska, E; Hellal, J; Mejri, S; Hammami, S; Marianneau, P; Calavas, D; Hénaux, V

2016-12-01

Rift Valley fever (RVF) is a vector-borne zoonotic disease that has caused widespread outbreaks throughout Africa and the Arabian Peninsula, with serious consequences for livestock-based economies and public health. Although there have never been any reports of RVF in Morocco, Algeria, Tunisia and Libya, it is a priority disease in the Maghreb, due to the threat of introduction of the virus through transboundary livestock movements or infected mosquito vectors. However, the implementation of surveillance activities and early warning contingency plans requires better knowledge of the epidemiological situation. We conducted a multicriteria decision analysis, integrating host distribution with a combination of important ecological factors that drive mosquito abundance, to identify hotspots and suitable time periods for RVF enzootic circulation (i.e. stable transmission at a low to moderate level for an extended period of time) and an RVF epizootic event (i.e. a sudden occurrence of a large number of infected animals over a large geographic area) in the Maghreb. We also modelled vector species distribution using available information on vector presence and habitat preference. We found that the northern regions of the Maghreb were moderately suitable for RVF enzootics, but highly suitable for RVF epizootics. The vector species distribution model identified these regions as the most favourable mosquito habitats. Due to the low density of animal hosts and arid conditions, the desert region showed low RVF suitability, except in oases. However, the presence of competent vectors in putative unsuitable areas underlines the need for further assessments of mosquito habitat preference. This study produced monthly RVF suitability maps useful for animal health managers and veterinary services involved in designing risk-based surveillance programmes. The suitability maps can be further enhanced using existing country-specific sources of information and by incorporating knowledge

Rat bite fever without fever.

Science.gov (United States)

Stehle, P; Dubuis, O; So, A; Dudler, J

2003-09-01

Rat bite fever is a rarely reported acute febrile bacterial illness caused by Streptobacillus moniliformis or Spirillum minus following a rat bite. It is classically characterised by abrupt onset of fever with rigors, myalgias, headache, and the appearance of a generalised maculopapular petechial skin rash. Polyarthritis complicates the course of the disease in up to 50% of infected patients, and numerous hurdles can make the diagnosis particularly difficult in the absence of fever or rash, as in the present case. A high degree of awareness is necessary to make the correct diagnosis in such cases. Diagnosis has important prognostic implications as the disease is potentially lethal, but easily treatable.

Dengue fever (image)

Science.gov (United States)

Dengue fever, or West Nile fever, is a mild viral illness transmitted by mosquitoes which causes fever, ... second exposure to the virus can result in Dengue hemorrhagic fever, a life-threatening illness.

Circumstantial Evidence of Possible Hot Spot Activity Outside Rhodes, Eastern Mediterranean Sea

OpenAIRE

Miliaresis, George

2014-01-01

Zouzias Dimitrios, St Seymour Karen, Miliaresis George, Vamvoukakis Costas (2008). Circumstantial Evidence of Possible Hot Spot Activity Outside Rhodes, Eastern Mediterranean Sea. 3rd International Conference on the Geology of the Tethys (8-11 January, 2008, South Valley University - Aswan). [Abstract in Program

Hemorrhagic Fever with Renal Syndrome (Korean Hemorrhagic Fever).

Science.gov (United States)

1986-07-23

fever , chills, nausea, headache and muscle ache in July 1985. One day after admission he developed petechial haemorrhage over his body and limbs and in...ftOA179 565 NENORNAGIC FEVER WI TH RENAL SYNDOMNE (KOREAN HEMORRHAIC FEVER )(U) KOREN UNIV SEOUL COLL OF MEDICINE N N LEE 23 JUL " DAD7-94-G-4616...34,, , " S , S S .S =. 5 5 . S S S * B M Lfl IC) uIeuCc FVM WITH RENAL SYNDR~OME (KOREAN EMORRHAGIC FEVER ) ANNUAL AND FINAL REPORT S HO WANG LIZB N.D. 5

A conceptual geochemical model of the geothermal system at Surprise Valley, CA

Science.gov (United States)

Fowler, Andrew P. G.; Ferguson, Colin; Cantwell, Carolyn A.; Zierenberg, Robert A.; McClain, James; Spycher, Nicolas; Dobson, Patrick

2018-03-01

Characterizing the geothermal system at Surprise Valley (SV), northeastern California, is important for determining the sustainability of the energy resource, and mitigating hazards associated with hydrothermal eruptions that last occurred in 1951. Previous geochemical studies of the area attempted to reconcile different hot spring compositions on the western and eastern sides of the valley using scenarios of dilution, equilibration at low temperatures, surface evaporation, and differences in rock type along flow paths. These models were primarily supported using classical geothermometry methods, and generally assumed that fluids in the Lake City mud volcano area on the western side of the valley best reflect the composition of a deep geothermal fluid. In this contribution, we address controls on hot spring compositions using a different suite of geochemical tools, including optimized multicomponent geochemistry (GeoT) models, hot spring fluid major and trace element measurements, mineralogical observations, and stable isotope measurements of hot spring fluids and precipitated carbonates. We synthesize the results into a conceptual geochemical model of the Surprise Valley geothermal system, and show that high-temperature (quartz, Na/K, Na/K/Ca) classical geothermometers fail to predict maximum subsurface temperatures because fluids re-equilibrated at progressively lower temperatures during outflow, including in the Lake City area. We propose a model where hot spring fluids originate as a mixture between a deep thermal brine and modern meteoric fluids, with a seasonally variable mixing ratio. The deep brine has deuterium values at least 3 to 4‰ lighter than any known groundwater or high-elevation snow previously measured in and adjacent to SV, suggesting it was recharged during the Pleistocene when meteoric fluids had lower deuterium values. The deuterium values and compositional characteristics of the deep brine have only been identified in thermal springs and

Immunogenicity of a recombinant Rift Valley fever MP-12-NSm deletion vaccine candidate in calves.

Science.gov (United States)

Morrill, John C; Laughlin, Richard C; Lokugamage, Nandadeva; Wu, Jing; Pugh, Roberta; Kanani, Pooja; Adams, L Garry; Makino, Shinji; Peters, C J

2013-10-09

The safety and immunogenicity of an authentic recombinant (ar) of the live, attenuated MP-12 Rift Valley fever (RVF) vaccine virus with a large deletion of the NSm gene in the pre-Gn region of the M RNA segment (arMP-12ΔNSm21/384) was tested in 4-6 month old Bos taurus calves. Phase I of this study evaluated the neutralizing antibody response, measured by 80% plaque reduction neutralization (PRNT80), and clinical response of calves to doses of 1 × 10(1) through 1 × 10(7) plaque forming units (PFU) administered subcutaneously (s.c.). Phase II evaluated the clinical and neutralizing antibody response of calves inoculated s.c. or intramuscularly (i.m.) with 1 × 10(3), 1 × 10(4) or 1 × 10(5)PFU of arMP-12ΔNSm21/384. No significant adverse clinical events were observed in the animals in these studies. Of all specimens tested, only one vaccine viral isolate was recovered and that virus retained the introduced deletion. In the Phase I study, there was no statistically significant difference in the PRNT80 response between the dosage groups though the difference in IgG response between the 1 × 10(1)PFU group and the 1 × 10(5)PFU group was statistically significant (pPFU dose group showing the least response. The Phase II study also showed no statistically significant difference in PRNT80 response between the dosage groups though the difference in RVFV-specific IgG values was significantly increased (pPFU versus those inoculated s.c. with 1 × 10(3) or 1 × 10(5)PFU. Although the study groups were small, these data suggest that 1 × 10(4) or 1 × 10(5)PFU of arMP-12ΔNSm21/384 administered i.m. to calves will consistently stimulate a presumably protective PRNT80 response for at least 91 days post inoculation. Further studies of arMP-12ΔNSm21/384 are warranted to explore its suitability as an efficacious livestock vaccine. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaluating growth effects from an imidacloprid treatment in black willow and eastern cottonwood cuttings

Science.gov (United States)

Luciano de Sene Fernandes; Ray A. Souter; Theodor D. Leininger

2015-01-01

Black willow (Salix nigra Marsh.) and eastern cottonwood (Populus deltoides Bartram ex Marsh.), two species native in the Lower Mississippi Alluvial Valley, have importance in short rotation woody crop (SRWC) systems for biomass production (Ruark 2006).

Analyzing tree cores to detect petroleum hydrocarbon-contaminated groundwater at a former landfill site in the community of Happy Valley-Goose Bay, eastern Canadian subarctic

DEFF Research Database (Denmark)

Fonkwe, Merline L D; Trapp, Stefan

2016-01-01

-gas chromatography-mass spectrometry. BTEX compounds were detected in tree cores, corroborating known groundwater contamination. A zone of anomalously high concentrations of total BTEX constituents was identified and recommended for monitoring by groundwater wells. Tree cores collected outside the landfill site......This research examines the feasibility of analyzing tree cores to detect benzene, toluene, ethylbenzene, and m, p, o-xylene (BTEX) compounds and methyl tertiary-butyl ether (MTBE) in groundwater in eastern Canada subarctic environments, using a former landfill site in the remote community of Happy...... Valley-Goose Bay, Labrador. Petroleum hydrocarbon contamination at the landfill site is the result of environmentally unsound pre-1990s disposal of households and industrial solid wastes. Tree cores were taken from trembling aspen, black spruce, and white birch and analyzed by headspace...

Evidence for slow late-glacial ice retreat in the upper Rangitata Valley, South Island, New Zealand

Science.gov (United States)

Shulmeister, J.; Fink, D.; Winkler, S.; Thackray, G. D.; Borsellino, R.; Hemmingsen, M.; Rittenour, T. M.

2018-04-01

A suite of cosmogenic radionuclide ages taken from boulders on lateral and latero-terminal moraines in the Rangitata Valley, eastern South Island, New Zealand demonstrates that relatively thick ice occupied valley reaches inland of the Rangitata Gorge until c. 21 ka. Thereafter ice began to thin, and by c. 17 ka it had retreated 33 km up-valley of the Rangitata Gorge to the Butler-Brabazon Downs, a structurally created basin in the upper Rangitata Valley. Despite its magnitude, this retreat represents a minor ice volume reduction from 21 ka to 17 ka, and numerous lateral moraines preserved suggest a relatively gradual retreat over that 4 ka period. In contrast to records from adjacent valleys, there is no evidence for an ice-collapse at c. 18 ka. We argue that the Rangitata record constitutes a more direct record of glacial response to deglacial climate than other records where glacial dynamics were influenced by proglacial lake development, such as the Rakaia Valley to the North and the major valleys in the Mackenzie Basin to the south-west. Our data supports the concept of a gradual warming during the early deglaciation in the South Island New Zealand.

Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania.

Science.gov (United States)

Mweya, Clement N; Kimera, Sharadhuli I; Mellau, Lesakit S B; Mboera, Leonard E G

2015-01-01

Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mosquitoes were sampled both outdoors and indoors using the Centre for Disease Control (CDC) light traps and Mosquito Magnets baited with attractants. Outdoor traps were placed in proximity with breeding sites and under canopy in banana plantations close to the sleeping places of animals. A total of 1,823 mosquitoes were collected, of which 87% (N=1,588) were Culex pipiens complex, 12% (N=226) Aedes aegypti, and 0.5% (N=9) Anopheles species. About two-thirds (67%; N=1,095) of C. pipiens complex and nearly 100% (N=225) of A. aegypti were trapped outdoors using Mosquito Magnets. All Anopheles species were trapped indoors using CDC light traps. There were variations in abundance of C. pipiens complex and A. aegypti among different ecological and vegetation habitats. Over three quarters (78%) of C. pipiens complex and most (85%) of the A. aegypti were trapped in banana and maize farms. Both C. pipiens complex and A. aegypti were more abundant in proximity with cattle and in semi-arid thorn bushes and lower Afro-montane. The highest number of mosquitoes was recorded in villages that were most affected during the RVF epidemic of 2007. Of the tested 150 pools of C. pipiens complex and 45 pools of A. aegypti, none was infected with RVF virus. These results provide insights into unique habitat characterisation relating to mosquito abundances and distribution in RVF epidemic-prone areas of Ngorongoro district in northern Tanzania.

Temporal trends in concentrations of DBCP and nitrate in groundwater in the eastern San Joaquin Valley, California, USA

Science.gov (United States)

Burow, K.R.; Dubrovsky, N.M.; Shelton, James L.

2007-01-01

Temporal monitoring of the pesticide 1,2-dibromo-3-chloropropane (DBCP) and nitrate and indicators of mean groundwater age were used to evaluate the transport and fate of agricultural chemicals in groundwater and to predict the long-term effects in the regional aquifer system in the eastern San Joaquin Valley, California. Twenty monitoring wells were installed on a transect along an approximate groundwater flow path. Concentrations of DBCP and nitrate in the wells were compared to concentrations in regional areal monitoring networks. DBCP persists at concentrations above the US Environmental Protection Agency's maximum contaminant level (MCL) at depths of nearly 40 m below the water table, more than 25 years after it was banned. Nitrate concentrations above the MCL reached depths of more than 20 m below the water table. Because of the intensive pumping and irrigation recharge, vertical flow paths are dominant. High concentrations (above MCLs) in the shallow part of the regional aquifer system will likely move deeper in the system, affecting both domestic and public-supply wells. The large fraction of old water (unaffected by agricultural chemicals) in deep monitoring wells suggests that it could take decades for concentrations to reach MCLs in deep, long-screened public-supply wells, however. ?? Springer-Verlag 2007.

Shallow Sedimentary Structure of the Brahmaputra Valley Constraint from Receiver Functions Analysis

Science.gov (United States)

Saikia, Sowrav; Chopra, Sumer; Baruah, Santanu; Singh, Upendra K.

2017-01-01

In this study, receiver functions from ten Broadband seismograph stations on Cenozoic sediment formations of Brahmaputra valley and its neighboring region in northeastern part of India are determined. Receiver function traces from this region show delay in peak by 1-2.5 s and associated minor peaks with the direct P-phase peak. Based on such observation, we try to image sedimentary structure of the Brahmaputra valley plain, adjacent Shillong plateau and Himalayan foredeep region. An adapted hybrid global waveform inversion technique has been applied to extract sedimentary basin structure beneath each site. The sedimentary cover of the basin is about 0.5-6.5 km thick across the valley, 0.5-1.0 km on Shillong plateau and 2.0-5.0 km in nearby foredeep region. We have found that sedimentary thickness increases from SW to NE along the Brahmaputra valley and towards the Eastern Himalayan syntaxes. The estimated sediment thickness and S wave velocity structure agree well with the results of previous active source, gravity, and deep borehole studies carried out in this region. The thick crustal low velocity sediment cover in Brahmaputra valley is expected to amplify ground motions during earthquakes and therefore important for seismic hazard assessment of the region.

Depth to water in the eastern Snake River Plain and surrounding tributary valleys, southwestern Idaho and eastern Oregon, calculated using water levels from 1980 to 1988

Science.gov (United States)

Maupin, Molly A.

1992-01-01

The vulnerability of ground water to contamination in Idaho is being assessed by the IDHW/DEQ (Idaho Department of Health and Welfare, Division of Environmental Quality), using a modified version of the Environmental Orotection Agency DRASTIC methods (Allers and others, 1985). The project was designed as a technique to: (1) Assign priorities for development of ground-water management and monitoring programs; (2) build support for, and public awareness of, vulnerability or ground water to contamination; (3) assist in the development of regulatory programs; and (4) provide access to technical data through the use of a GIS (geographic information system) (C. Grantha,, Idaho Department of Health and Welfare, written commun., 1989). A digital representation of first-encountered water below land surface is an important element in evaluating vulnerability of ground water to contamination. Depth-to-water values were developed using existing data and computer software to construct a GIS data set to be combined with a sols data set developed by the SCS (Soil Conservation Service) and IDHW/WQB (Idaho Department of Health and Welfare/Water Quality Bureau), and a recharge data set developed by the IDWR/RSF (Idaho Department of Water Resources/Remote Sensing Facility). The USGS (U.S. Geological Survey) developed digital depth-to-water values for eleven 1:100,000-scale quadrangles on the eastern Snake River Plain and surrounding tributary valleys.

The influence of current and future climate on the spatial distribution of coccidioidomycosis in the southwestern United States

Science.gov (United States)

Gorris, M. E.; Hoffman, F. M.; Zender, C. S.; Treseder, K. K.; Randerson, J. T.

2017-12-01

Coccidioidomycosis, otherwise known as valley fever, is an infectious fungal disease currently endemic to the southwestern U.S. The magnitude, spatial distribution, and seasonality of valley fever incidence is shaped by variations in regional climate. As such, climate change may cause new communities to become at risk for contracting this disease. Humans contract valley fever by inhaling fungal spores of the genus Coccidioides. Coccidioides grow in the soil as a mycelium, and when stressed, autolyze into spores 2-5 µm in length. Spores can become airborne from any natural or anthropogenic soil disturbance, which can be exacerbated by dry soil conditions. Understanding the relationship between climate and valley fever incidence is critical for future disease risk management. We explored several multivariate techniques to create a predictive model of county-level valley fever incidence throughout the southwestern U.S., including Arizona, California, New Mexico, Nevada, and Utah. We incorporated surface air temperature, precipitation, soil moisture, surface dust concentrations, leaf area index, and the amount of agricultural land, all of which influence valley fever incidence. A log-linear regression model that incorporated surface air temperature, soil moisture, surface dust concentration, and the amount of agricultural land explained 34% of the county-level variance in annual average valley fever incidence. We used this model to predict valley fever incidence for the Representative Concentration Pathway 8.5 using simulation output from the Community Earth System Model. In our analysis, we describe how regional hotspots of valley fever incidence may shift with sustained warming and drying in the southwestern U.S. Our predictive model of valley fever incidence may help mitigate future health impacts of valley fever by informing health officials and policy makers of the climate conditions suitable for disease outbreak.

Residence Times in Central Valley Aquifers Recharged by Dammed Rivers

Science.gov (United States)

Loustale, M.; Paukert Vankeuren, A. N.; Visser, A.

2017-12-01

Groundwater is a vital resource for California, providing between 30-60% of the state's water supply. Recent emphasis on groundwater sustainability has induced a push to characterize recharge rates and residence times for high priority aquifers, including most aquifers in California's Central Valley. Flows in almost all rivers from the western Sierra to the Central Valley are controlled by dams, altering natural flow patterns and recharge to local aquifers. In eastern Sacramento, unconfined and confined shallow aquifers (depth recharged by a losing reach of the Lower American River, despite the presence of levees with slurry cut-off walls.1 Flow in the Lower American River is controlled through the operation of the Folsom and Nimbus Dams, with a minimum flow of 500 cfs. Water table elevation in wells in close proximity to the river are compared to river stage to determine the effect of river stage on groundwater recharge rates. Additionally, Tritium-3Helium dates and stable isotopes (∂18O and ∂2H) have been measured in monitoring wells 200- 2400 ft lateral distance from the river, and depths of 25 -225 feet BGS. Variation in groundwater age in the vertical and horizontal directions are used to determine groundwater flow path and velocity. These data are then used to calculate residence time of groundwater in the unconfined and confined aquifer systems for the Central Valley in eastern Sacramento. Applying groundwater age tracers can benefit future compliance metrics of the California Sustainable Groundwater Resources Act (SGMA), by quantifying river seepage rates and impacts of groundwater management on surface water resources. 1Moran et al., UCRL-TR-203258, 2004.

Upper Neogene stratigraphy and tectonics of Death Valley — a review

Science.gov (United States)

Knott, J. R.; Sarna-Wojcicki, A. M.; Machette, M. N.; Klinger, R. E.

2005-12-01

New tephrochronologic, soil-stratigraphic and radiometric-dating studies over the last 10 years have generated a robust numerical stratigraphy for Upper Neogene sedimentary deposits throughout Death Valley. Critical to this improved stratigraphy are correlated or radiometrically-dated tephra beds and tuffs that range in age from > 3.58 Ma to Mormon Point. This new geochronology also establishes maximum and minimum ages for Quaternary alluvial fans and Lake Manly deposits. Facies associated with the tephra beds show that ˜3.3 Ma the Furnace Creek basin was a northwest-southeast-trending lake flanked by alluvial fans. This paleolake extended from the Furnace Creek to Ubehebe. Based on the new stratigraphy, the Death Valley fault system can be divided into four main fault zones: the dextral, Quaternary-age Northern Death Valley fault zone; the dextral, pre-Quaternary Furnace Creek fault zone; the oblique-normal Black Mountains fault zone; and the dextral Southern Death Valley fault zone. Post - 3.3 Ma geometric, structural, and kinematic changes in the Black Mountains and Towne Pass fault zones led to the break up of Furnace Creek basin and uplift of the Copper Canyon and Nova basins. Internal kinematics of northern Death Valley are interpreted as either rotation of blocks or normal slip along the northeast-southwest-trending Towne Pass and Tin Mountain fault zones within the Eastern California shear zone.

Geographic patterns and environmental factors associated with human yellow fever presence in the Americas.

Science.gov (United States)

Hamrick, Patricia Najera; Aldighieri, Sylvain; Machado, Gustavo; Leonel, Deise Galan; Vilca, Luz Maria; Uriona, Sonia; Schneider, Maria Cristina

2017-09-01

In the Americas, yellow fever virus transmission is a latent threat due to the proximity between urban and wild environments. Although yellow fever has nearly vanished from North and Central America, there are still 13 countries in the Americas considered endemic by the World Health Organization. Human cases usually occur as a result of the exposure to sylvatic yellow fever in tropical forested environments; but urban outbreaks reported during the last decade demonstrate that the risk in this environment still exists. The objective of this study was to identify spatial patterns and the relationship between key geographic and environmental factors with the distribution of yellow fever human cases in the Americas. An ecological study was carried out to analyze yellow fever human cases reported to the Pan American Health Organization from 2000 to 2014, aggregated by second administrative level subdivisions (counties). Presence of yellow fever by county was used as the outcome variable and eight geo-environmental factors were used as independent variables. Spatial analysis was performed to identify and examine natural settings per county. Subsequently, a multivariable logistic regression model was built. During the study period, 1,164 cases were reported in eight out of the 13 endemic countries. Nearly 83.8% of these cases were concentrated in three countries: Peru (37.4%), Brazil (28.1%) and Colombia (18.4%); and distributed in 57 states/provinces, specifically in 286 counties (3.4% of total counties). Yellow fever presence was significantly associated with altitude, rain, diversity of non-human primate hosts and temperature. A positive spatial autocorrelation revealed a clustered geographic pattern in 138/286 yellow fever positive counties (48.3%). A clustered geographic pattern of yellow fever was identified mostly along the Andes eastern foothills. This risk map could support health policies in endemic countries. Geo-environmental factors associated with presence

Fever

Science.gov (United States)

... also cause fevers. Some examples are: Arthritis or connective tissue illnesses such as rheumatoid arthritis and systemic lupus erythematosus Ulcerative colitis and Crohn disease Vasculitis or periarteritis nodosa The first symptom of a cancer may be a fever. This is particularly true ...

Lichenized and lichenicolous fungi from the valley ‘Ochsental’ (Eastern Alps, Vorarlberg, Austria)

Science.gov (United States)

Bilovitz, Peter Othmar; Mayrhofer, Helmut

2016-01-01

A list of 100 lichen species and 4 lichenicolous fungi from the valley ‘Ochsental’ is presented. Lecidea laboriosa is new to Austria. Lecanora swartzii, Orphniospora moriopsis, Protothelenella corrosa and the lichenicolous fungus Cercidospora stereocaulorum are new to the province of Vorarlberg. PMID:26869748

A Systematic Scoping Study of the Socio-Economic Impact of Rift Valley Fever: Research Gaps and Needs.

Science.gov (United States)

Peyre, M; Chevalier, V; Abdo-Salem, S; Velthuis, A; Antoine-Moussiaux, N; Thiry, E; Roger, F

2015-08-01

Rift Valley fever (RVF) is a severe mosquito-borne disease affecting humans and domestic ruminants. RVF virus has been reported in most African countries, as well as in the Arabic Peninsula. This paper reviews the different types of socio-economic impact induced by RVF disease and the attempts to evaluate them. Of the 52 papers selected for this review, 13 types of socio-economic impact were identified according to the sector impacted, the level and temporal scale of the impact. RVF has a dramatic impact on producers and livestock industries, affecting public and animal health, food security and the livelihood of the pastoralist communities. RVF also has an impact on international trade and other agro-industries. The risk of introducing RVF into disease-free countries via the importation of an infected animal or mosquito is real, and the consequent restriction of access to export markets may induce dramatic economic consequences for national and local economies. Despite the important threat of RVF, few studies have been conducted to assess the socio-economic impact of the disease. The 17 studies identified for quantitative analysis in this review relied only on partial cost analysis, with limited reference to mid- and long-term impact, public health or risk mitigation measures. However, the estimated impacts were high (ranging from $5 to $470 million USD losses). To reduce the impact of RVF, early detection and rapid response should be implemented. Comprehensive disease impact studies are required to provide decision-makers with science-based information on the best intervention measure to implement ensuring efficient resource allocation. Through the analysis of RVF socio-economic impact, this scoping study proposes insights into the mechanisms underpinning its often-underestimated importance. This study highlights the need for comparative socio-economic studies to help decision-makers with their choices related to RVF disease management. © 2014 The Authors

The sero-epidemiology of Rift Valley fever in people in the Lake Victoria Basin of western Kenya.

Directory of Open Access Journals (Sweden)

Elizabeth Anne Jessie Cook

2017-07-01

Full Text Available Rift Valley fever virus (RVFV is a zoonotic arbovirus affecting livestock and people. This study was conducted in western Kenya where RVFV outbreaks have not previously been reported. The aims were to document the seroprevalence and risk factors for RVFV antibodies in a community-based sample from western Kenya and compare this with slaughterhouse workers in the same region who are considered a high-risk group for RVFV exposure. The study was conducted in western Kenya between July 2010 and November 2012. Individuals were recruited from randomly selected homesteads and a census of slaughterhouses. Structured questionnaire tools were used to collect information on demographic data, health, and risk factors for zoonotic disease exposure. Indirect ELISA on serum samples determined seropositivity to RVFV. Risk factor analysis for RVFV seropositivity was conducted using multi-level logistic regression. A total of 1861 individuals were sampled in 384 homesteads. The seroprevalence of RVFV in the community was 0.8% (95% CI 0.5-1.3. The variables significantly associated with RVFV seropositivity in the community were increasing age (OR 1.2; 95% CI 1.1-1.4, p<0.001, and slaughtering cattle at the homestead (OR 3.3; 95% CI 1.0-10.5, p = 0.047. A total of 553 slaughterhouse workers were sampled in 84 ruminant slaughterhouses. The seroprevalence of RVFV in slaughterhouse workers was 2.5% (95% CI 1.5-4.2. Being the slaughterman, the person who cuts the animal's throat (OR 3.5; 95% CI 1.0-12.1, p = 0.047, was significantly associated with RVFV seropositivity. This study investigated and compared the epidemiology of RVFV between community members and slaughterhouse workers in western Kenya. The data demonstrate that slaughtering animals is a risk factor for RVFV seropositivity and that slaughterhouse workers are a high-risk group for RVFV seropositivity in this environment. These risk factors have been previously reported in other studies providing further

The sero-epidemiology of Rift Valley fever in people in the Lake Victoria Basin of western Kenya.

Science.gov (United States)

Cook, Elizabeth Anne Jessie; Grossi-Soyster, Elysse Noel; de Glanville, William Anson; Thomas, Lian Francesca; Kariuki, Samuel; Bronsvoort, Barend Mark de Clare; Wamae, Claire Njeri; LaBeaud, Angelle Desiree; Fèvre, Eric Maurice

2017-07-01

Rift Valley fever virus (RVFV) is a zoonotic arbovirus affecting livestock and people. This study was conducted in western Kenya where RVFV outbreaks have not previously been reported. The aims were to document the seroprevalence and risk factors for RVFV antibodies in a community-based sample from western Kenya and compare this with slaughterhouse workers in the same region who are considered a high-risk group for RVFV exposure. The study was conducted in western Kenya between July 2010 and November 2012. Individuals were recruited from randomly selected homesteads and a census of slaughterhouses. Structured questionnaire tools were used to collect information on demographic data, health, and risk factors for zoonotic disease exposure. Indirect ELISA on serum samples determined seropositivity to RVFV. Risk factor analysis for RVFV seropositivity was conducted using multi-level logistic regression. A total of 1861 individuals were sampled in 384 homesteads. The seroprevalence of RVFV in the community was 0.8% (95% CI 0.5-1.3). The variables significantly associated with RVFV seropositivity in the community were increasing age (OR 1.2; 95% CI 1.1-1.4, p<0.001), and slaughtering cattle at the homestead (OR 3.3; 95% CI 1.0-10.5, p = 0.047). A total of 553 slaughterhouse workers were sampled in 84 ruminant slaughterhouses. The seroprevalence of RVFV in slaughterhouse workers was 2.5% (95% CI 1.5-4.2). Being the slaughterman, the person who cuts the animal's throat (OR 3.5; 95% CI 1.0-12.1, p = 0.047), was significantly associated with RVFV seropositivity. This study investigated and compared the epidemiology of RVFV between community members and slaughterhouse workers in western Kenya. The data demonstrate that slaughtering animals is a risk factor for RVFV seropositivity and that slaughterhouse workers are a high-risk group for RVFV seropositivity in this environment. These risk factors have been previously reported in other studies providing further evidence for RVFV

Development of a novel subunit vaccine against East Coast fever based on the Theileria parva sporozoite surface protein p67

NARCIS (Netherlands)

Kaba, S.A.

2003-01-01

Theileriaparva is an intracellular protozoan parasite and the causative agent of a lethal cattle disease, called East Coast fever (ECF). This disease poses a major constraint on improvement of cattle production in Eastern, Central

Simultaneous detection of IgG antibodies associated with viral hemorrhagic fever by a multiplexed Luminex-based immunoassay.

Science.gov (United States)

Wu, Wei; Zhang, Shuo; Qu, Jing; Zhang, Quanfu; Li, Chuan; Li, Jiandong; Jin, Cong; Liang, Mifang; Li, Dexin

2014-07-17

Viral hemorrhagic fevers (VHFs) are worldwide diseases caused by several kinds of viruses. With the emergence of new viruses, advanced diagnostic methods are urgently needed for identification of VHFs. Based on Luminex xMAP technology, a rapid, sensitive, multi-pathogen and high-throughput method which could simultaneously detect hemorrhagic fever viruses (HFVs) specific IgG antibodies was developed. Recombinant antigens of nine HFVs including Hantaan virus (HTNV), Seoul virus (SEOV), Puumala virus (PUUV), Andes virus (ANDV), Sin Nombre virus (SNV), Crimean-Congo hemorrhagic fever virus (CCHFV), Rift Valley fever virus (RVFV), Severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) and dengue virus (DENV) were produced and purified from a prokaryotic expression system and the influence of the coupling amount was investigated. Cross-reactions among antigens and their rabbit immune sera were evaluated. Serum samples collected from 51 laboratory confirmed hemorrhagic fever with renal syndrome (HFRS) patients, 43 confirmed SFTS patients and 88 healthy donors were analyzed. Results showed that recombinant nucleocapsid protein of the five viruses belonging to the genus Hantavirus, had serological cross-reactivity with their corresponding rabbit immune sera, but not apparent with immune sera of other four viruses. Evaluation of this new method with clinical serum samples showed 98.04% diagnostic sensitivity for HFRS, 90.70% for SFTS detection and the specificity was ranging from 66.67% to 100.00%. The multiplexed Luminex-based immunoassay has firstly been established in our study, which provides a potentially reliable diagnostic tool for IgG antibody detection of VHFs. Copyright © 2014 Elsevier B.V. All rights reserved.

Identification of pathogens for differential diagnosis of fever with jaundice in the Central African Republic: a retrospective assessment, 2008-2010.

Science.gov (United States)

Gadia, Christelle Luce Bobossi; Manirakiza, Alexandre; Tekpa, Gaspard; Konamna, Xavier; Vickos, Ulrich; Nakoune, Emmanuel

2017-11-29

Febrile jaundice results clinically in generalized yellow coloration of the teguments and mucous membranes due to excess plasma bilirubin, accompanied by fever. Two types are found: conjugated and unconjugated bilirubin jaundice. Jaundice is a sign in several diseases due to viruses (viral hepatitis and arbovirus), parasites (malaria) and bacteria (leptospirosis). In the Central African Republic (CAR), only yellow fever is included on the list of diseases for surveillance. The aim of this study was to identify the other pathogens that can cause febrile jaundice, for better management of patients. Between 2008 and 2010, 198 sera negative for yellow fever IgM were randomly selected from 2177 samples collected during yellow fever surveillance. Laboratory analyses targeted four groups of pathogens: hepatitis B, C, delta and E viruses; dengue, chikungunya, Zika, Crimean-Congo haemorrhagic fever, West Nile and Rift Valley arboviruses; malaria parasites; and bacteria (leptospirosis). Overall, 30.9% sera were positive for hepatitis B, 20.2% for hepatitis E, 12.3% for hepatitis C and 8.2% for malaria. The majority of positive sera (40.4%) were from people aged 16-30 years. Co-infection with at least two of these pathogens was also found. These findings suggest that a systematic investigation should be undertaken of infectious agents that cause febrile jaundice in the CAR.

Evaluation of positive Rift Valley fever virus formalin-fixed paraffin embedded samples as a source of sequence data for retrospective phylogenetic analysis.

Science.gov (United States)

Mubemba, B; Thompson, P N; Odendaal, L; Coetzee, P; Venter, E H

2017-05-01

Rift Valley fever (RVF), caused by an arthropod borne Phlebovirus in the family Bunyaviridae, is a haemorrhagic disease that affects ruminants and humans. Due to the zoonotic nature of the virus, a biosafety level 3 laboratory is required for isolation of the virus. Fresh and frozen samples are the preferred sample type for isolation and acquisition of sequence data. However, these samples are scarce in addition to posing a health risk to laboratory personnel. Archived formalin-fixed, paraffin-embedded (FFPE) tissue samples are safe and readily available, however FFPE derived RNA is in most cases degraded and cross-linked in peptide bonds and it is unknown whether the sample type would be suitable as reference material for retrospective phylogenetic studies. A RT-PCR assay targeting a 490 nt portion of the structural G N glycoprotein encoding gene of the RVFV M-segment was applied to total RNA extracted from archived RVFV positive FFPE samples. Several attempts to obtain target amplicons were unsuccessful. FFPE samples were then analysed using next generation sequencing (NGS), i.e. Truseq ® (Illumina) and sequenced on the Miseq ® genome analyser (Illumina). Using reference mapping, gapped virus sequence data of varying degrees of shallow depth was aligned to a reference sequence. However, the NGS did not yield long enough contigs that consistently covered the same genome regions in all samples to allow phylogenetic analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Identification of Dengue and Chikungunya Cases Among Suspected Cases of Yellow Fever in the Democratic Republic of the Congo.

Science.gov (United States)

Makiala-Mandanda, Sheila; Ahuka-Mundeke, Steve; Abbate, Jessica L; Pukuta-Simbu, Elisabeth; Nsio-Mbeta, Justus; Berthet, Nicolas; Leroy, Eric Maurice; Becquart, Pierre; Muyembe-Tamfum, Jean-Jacques

2018-05-16

For more than 95% of acute febrile jaundice cases identified through surveillance for yellow fever, a reemerging arthropod-borne viral disease, no etiological exploration is ever done. The aim of this study was to test for other arthropod-borne viruses that can induce the same symptoms in patients enrolled in the yellow fever surveillance in the Democratic Republic of the Congo (DRC). Of 652 patients included in the surveillance of yellow fever in DRC from January 2003 to January 2012, 453 patients that tested negative for yellow fever virus (YFV) immunoglobulin M (IgM) antibodies were selected for the study. Real-time polymerase chain reaction was performed for the detection of dengue, West Nile, Chikungunya, O'nyong-nyong, Rift Valley fever, Zika, and YFV. The average age of patients was 22.1 years. We reported 16 cases (3.5%; confidence interval [CI]: 0.8-5.2) of dengue (serotypes 1 and 2) and 2 cases (0.4%; CI: 0.0-1.0) of Chikungunya. Three patients were co-infected with the two serotypes of dengue virus. Three cases of dengue were found in early July 2010 from the city of Titule (Oriental province) during a laboratory-confirmed outbreak of yellow fever, suggesting simultaneous circulation of dengue and yellow fever viruses. This study showed that dengue and Chikungunya viruses are potential causes of acute febrile jaundice in the DRC and highlights the need to consider dengue and Chikungunya diagnosis in the integrated disease surveillance and response program in the DRC. A prospective study is necessary to establish the epidemiology of these diseases.

MP-12 virus containing the clone 13 deletion in the NSs gene prevents lethal disease when administered after Rift Valley fever virus infection in hamsters.

Science.gov (United States)

Gowen, Brian B; Westover, Jonna B; Sefing, Eric J; Bailey, Kevin W; Nishiyama, Shoko; Wandersee, Luci; Scharton, Dionna; Jung, Kie-Hoon; Ikegami, Tetsuro

2015-01-01

Rift Valley fever virus (RVFV; Bunyaviridae, Phlebovirus) causes a range of illnesses that include retinitis, fulminant hepatitis, neurologic disease, and hemorrhagic fever. In hospitalized individuals, case fatality rates can be as high as 10-20%. There are no vaccines or antivirals approved for human use to prevent or treat severe RVFV infections. We previously tested the efficacy of the MP-12 vaccine strain and related variants with NSs truncations as a post-exposure prophylaxis in mice infected with wild-type pathogenic RVFV strain ZH501. Post-exposure efficacy of the rMP12-C13type, a recombinant MP-12 vaccine virus which encodes an in-frame truncation removing 69% of the NSs protein, resulted in 30% survival when administering the virus within 30 min of subcutaneous ZH501 challenge in mice, while the parental MP-12 virus conferred no protection by post-exposure vaccination. Here, we demonstrate uniform protection of hamsters by post-exposure vaccination with rMP12-C13type administered 6 h post-ZH501 infection while no efficacy was observed with the parental MP-12 virus. Notably, both the MP-12 and rMP12-C13type viruses were highly effective (100% protection) when administered 21 days prior to challenge. In a subsequent study delaying vaccination until 8, 12, and 24 h post-RVFV exposure, we observed 80, 70, and 30% survival, respectively. Our findings indicate that the rapid protective innate immune response elicited by rMP12-C13type may be due to the truncated NSs protein, suggesting that the resulting functional inactivation of NSs plays an important role in the observed post-exposure efficacy. Taken together, the data demonstrate that post-exposure vaccination with rMP12-C13type is effective in limiting ZH501 replication and associated disease in standard pre-exposure vaccination and post-challenge treatment models of RVFV infection, and suggest an extended post-exposure prophylaxis window beyond that initially observed in mice.

Valley Fever

Science.gov (United States)

... Coccidioides. The fungi live in the soil of dry areas like the southwestern U.S. You get it ... that expose them to soil dust. These include construction workers, agricultural workers, and military forces doing field ...

Reverse-phase phosphoproteome analysis of signaling pathways induced by Rift valley fever virus in human small airway epithelial cells.

Directory of Open Access Journals (Sweden)

Taissia G Popova

Full Text Available Rift valley fever virus (RVFV infection is an emerging zoonotic disease endemic in many countries of sub-Saharan Africa and in Egypt. In this study we show that human small airway epithelial cells are highly susceptible to RVFV virulent strain ZH-501 and the attenuated strain MP-12. We used the reverse-phase protein arrays technology to identify phosphoprotein signaling pathways modulated during infection of cultured airway epithelium. ZH-501 infection induced activation of MAP kinases (p38, JNK and ERK and downstream transcriptional factors [STAT1 (Y701, ATF2 (T69/71, MSK1 (S360 and CREB (S133]. NF-κB phosphorylation was also increased. Activation of p53 (S15, S46 correlated with the increased levels of cleaved effector caspase-3, -6 and -7, indicating activation of the extrinsic apoptotic pathway. RVFV infection downregulated phosphorylation of a major anti-apoptotic regulator of survival pathways, AKT (S473, along with phosphorylation of FOX 01/03 (T24/31 which controls cell cycle arrest downstream from AKT. Consistent with this, the level of apoptosis inhibitor XIAP was decreased. However, the intrinsic apoptotic pathway marker, caspase-9, demonstrated only a marginal activation accompanied by an increased level of the inhibitor of apoptosome formation, HSP27. Concentration of the autophagy marker, LC3B, which often accompanies the pro-survival signaling, was decreased. Cumulatively, our analysis of RVFV infection in lung epithelium indicated a viral strategy directed toward the control of cell apoptosis through a number of transcriptional factors. Analyses of MP-12 titers in challenged cells in the presence of MAPK inhibitors indicated that activation of p38 represents a protective cell response while ERK activation controls viral replication.

Large-scale chromatin immunoprecipitation with promoter sequence microarray analysis of the interaction of the NSs protein of Rift Valley fever virus with regulatory DNA regions of the host genome.

Science.gov (United States)

Benferhat, Rima; Josse, Thibaut; Albaud, Benoit; Gentien, David; Mansuroglu, Zeyni; Marcato, Vasco; Souès, Sylvie; Le Bonniec, Bernard; Bouloy, Michèle; Bonnefoy, Eliette

2012-10-01

Rift Valley fever virus (RVFV) is a highly pathogenic Phlebovirus that infects humans and ruminants. Initially confined to Africa, RVFV has spread outside Africa and presently represents a high risk to other geographic regions. It is responsible for high fatality rates in sheep and cattle. In humans, RVFV can induce hepatitis, encephalitis, retinitis, or fatal hemorrhagic fever. The nonstructural NSs protein that is the major virulence factor is found in the nuclei of infected cells where it associates with cellular transcription factors and cofactors. In previous work, we have shown that NSs interacts with the promoter region of the beta interferon gene abnormally maintaining the promoter in a repressed state. In this work, we performed a genome-wide analysis of the interactions between NSs and the host genome using a genome-wide chromatin immunoprecipitation combined with promoter sequence microarray, the ChIP-on-chip technique. Several cellular promoter regions were identified as significantly interacting with NSs, and the establishment of NSs interactions with these regions was often found linked to deregulation of expression of the corresponding genes. Among annotated NSs-interacting genes were present not only genes regulating innate immunity and inflammation but also genes regulating cellular pathways that have not yet been identified as targeted by RVFV. Several of these pathways, such as cell adhesion, axonal guidance, development, and coagulation were closely related to RVFV-induced disorders. In particular, we show in this work that NSs targeted and modified the expression of genes coding for coagulation factors, demonstrating for the first time that this hemorrhagic virus impairs the host coagulation cascade at the transcriptional level.

A Q fever case mimicking crimean-congo haemorrhagic fever

Directory of Open Access Journals (Sweden)

O Karabay

2011-01-01

Full Text Available Coxiella burnetii is the bacterium that causes Q fever. Human infection is mainly transmitted from cattle, goats and sheep. The disease is usually self-limited. Pneumonia and hepatitis are the most common clinical manifestations. In this study, we present a case of Q fever from the western part of Turkey mimicking Crimean-Congo haemorrhagic fever (CCHF in terms of clinical and laboratory findings.

[Feeding pattern of Rift Valley Fever virus vectors in Senegal. Implications in the disease epidemiology].

Science.gov (United States)

Ba, Y; Diallo, D; Dia, I; Diallo, M

2006-10-01

During the rainy season 2003, an entomological survey was undertaken in the Sahelian bioclimatic zone of the Ferlo area in northern Senegal, in order to evaluate the degree of interaction between Rift valley fever (RVF) virus vectors and domestic animals and to determine the role of natural vertebrate hosts in the transmission and maintenance cycle. The study of vector-host contact was carried out under bed net traps using man, cow, sheep, chicken as bait whereas the RVFV vectors-vertebrate host interactions were studied through the analysis by an ELISA technique of the origin of the blood meals from naturally engorged females collected by aspiration. Blood meals sources were determined using a set of eight antibodies. Overall, the different known RVFV vectors (Culex poicilipes, Aedes vexans and Aedes ochraceus) were opportunistic although the bovine-baited net was, as far the more effective trap with 53.6% of collected mosquitoes. It was followed by the sheep-baited net (16.7%), man-baited net (12.6%) and chicken-baited net (11.6%). The more effectiveness of the bovine-baited net confirms the degree of implication of this host in RVF epidemiology. The study of vector-hosts interactions in nature showed that among the 1,112 mosquito blood meals tested, 701 were identified of which 693 were from Aedes vexans. The percentage of non-reacting blood meal was 36.7% whereas 16.9 % of the blood meals were taken at least on two vertebrate hosts. Overall, 53.2% of the blood meals from Ae. vexans were taken on equine, 18.6% on bovines, 7.1% on sheep and 0.6% on human. No blood meal was taken on rodent. The greatest diversity was observed in August. These host feedings patterns show that although equine is known to play a minor role in RVF epidemiology a thorough attention should be made to this host with regard to the percentage of blood meals taken in this host. The low percentage of blood meals taken on human could probably explain the low human infection rate observed up

Certain peculiarities of the prevalence of typhoid fever under conditions of the environmental pollution

Energy Technology Data Exchange (ETDEWEB)

Toichuev, R. M.; Mamytova, M. [Institute of Medical Problems of the Southern Branch, Osh(Kyrgyzstan)

2012-09-15

; morbidity rates were 0.1 cases per 100000 adult population and 0.3 cases per 100000 child population. A total of 86 patients with TF were recorded in Jalal-Abad Province. Of them, 31 patients were children under 14. Morbidity rates were as follows: 8.3 and 9.2, respectively, i.e. 10 times higher as compared to the other provinces of the Republic. To detect the causes of TF we studied the prevalence of the disease considering the location of water sources. The incidence of TF among the residents of the Mayluusuu Valley, the water of which is polluted with radionicles, was 124.7 (adult population) and 251.6 (child population) in 2010 and 130.9 and 162.5, respectively, in 2011. Moreover, starting from 2006 typhoid fever cases have been reported in the winter and spring times among the residents of the Mayluusuu Valley. In 2010, 52 (73.23%) out of the total of 71 patients with TF admitted to the hospitals in Jalal-Abad Province were the residents of the Mayluusuu Valley, as compared to 64 (74.45%) out of the total 86 patients reported in 2011. Thus, the higher TF morbidity rate in the south of the Kyrgyz Republic is due to poor sanitation in the region (the Mayluusuu Valley), i.e. this radionuclide-polluted area remains one of the typhoid fever 'hot-spots'. (author)

Hot water in the Long Valley Caldera—The benefits and hazards of this large natural resource

Science.gov (United States)

Evans, William C.; Hurwitz, Shaul; Bergfeld, Deborah; Howle, James F.

2018-03-26

The volcanic processes that have shaped the Long Valley Caldera in eastern California have also created an abundant supply of natural hot water. This natural resource provides benefits to many users, including power generation at the Casa Diablo Geothermal Plant, warm water for a state fish hatchery, and beautiful scenic areas such as Hot Creek gorge for visitors. However, some features can be dangerous because of sudden and unpredictable changes in the location and flow rate of boiling water. The U.S. Geological Survey monitors several aspects of the hydrothermal system in the Long Valley Caldera including temperature, flow rate, and water chemistry.

[Surveillance data on typhoid fever and paratyphoid fever in 2015, China].

Science.gov (United States)

Liu, F F; Zhao, S L; Chen, Q; Chang, Z R; Zhang, J; Zheng, Y M; Luo, L; Ran, L; Liao, Q H

2017-06-10

Objective: Through analyzing the surveillance data on typhoid fever and paratyphoid fever in 2015 to understand the related epidemiological features and most possible clustering areas of high incidence. Methods: Individual data was collected from the passive surveillance program and analyzed by descriptive statistic method. Characteristics on seasonal, regional and distribution of the diseases were described. Spatial-temporal clustering characteristics were estimated, under the retrospective space-time method. Results: A total of 8 850 typhoid fever cases were reported from the surveillance system, with incidence rate as 0.65/100 000. The number of paratyphoid fever cases was 2 794, with incidence rate as 0.21/100 000. Both cases of typhoid fever and paratyphoid fever occurred all year round, with high epidemic season from May to October. Most cases involved farmers (39.68 % ), children (15.89 % ) and students (12.01 % ). Children under 5 years showed the highest incidence rate. Retrospective space-time analysis for provinces with high incidence rates would include Yunnan, Guangxi, Guizhou, Hunan and Guangdong, indicating the first and second class clusters were mainly distributed near the bordering adjacent districts and counties among the provinces. Conclusion: In 2015, the prevalence rates of typhoid fever and paratyphoid fever were low, however with regional high prevalence areas. Cross regional transmission existed among provinces with high incidence rates which might be responsible for the clusters to appear in these areas.

Yellow fever

Science.gov (United States)

... to thrive. Blood tests can confirm the diagnosis. Treatment There is no specific treatment for yellow fever. ... SJ, Endy TP, Rothman AL, Barrett AD. Flaviviruses (dengue, yellow fever, Japanese encephalitis, West Nile encephalitis, St. ...

Inter-epidemic abundance and distribution of potential mosquito vectors for Rift Valley fever virus in Ngorongoro district, Tanzania

Directory of Open Access Journals (Sweden)

Clement N. Mweya

2015-01-01

Full Text Available Background: Rift Valley fever (RVF is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. Objective: To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. Methods: A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mosquitoes were sampled both outdoors and indoors using the Centre for Disease Control (CDC light traps and Mosquito Magnets baited with attractants. Outdoor traps were placed in proximity with breeding sites and under canopy in banana plantations close to the sleeping places of animals. Results: A total of 1,823 mosquitoes were collected, of which 87% (N=1,588 were Culex pipiens complex, 12% (N=226 Aedes aegypti, and 0.5% (N=9 Anopheles species. About two-thirds (67%; N=1,095 of C. pipiens complex and nearly 100% (N=225 of A. aegypti were trapped outdoors using Mosquito Magnets. All Anopheles species were trapped indoors using CDC light traps. There were variations in abundance of C. pipiens complex and A. aegypti among different ecological and vegetation habitats. Over three quarters (78% of C. pipiens complex and most (85% of the A. aegypti were trapped in banana and maize farms. Both C. pipiens complex and A. aegypti were more abundant in proximity with cattle and in semi-arid thorn bushes and lower Afro-montane. The highest number of mosquitoes was recorded in villages that were most affected during the RVF epidemic of 2007. Of the tested 150 pools of C. pipiens complex and 45 pools of A. aegypti, none was infected with RVF virus. Conclusions: These results provide insights into unique habitat characterisation relating to mosquito abundances and distribution in RVF epidemic-prone areas of Ngorongoro district in northern Tanzania.

Statistical modeling of the abundance of vectors of West African Rift Valley fever in Barkédji, Senegal.

Directory of Open Access Journals (Sweden)

Cheikh Talla

Full Text Available Rift Valley fever is an emerging mosquito-borne disease that represents a threat to human and animal health. The exophilic and exophagic behavior of the two main vector in West Africa (Aedes vexans and Culex poicilipes, adverse events post-vaccination, and lack of treatment, render ineffective the disease control. Therefore it is essential to develop an information system that facilitates decision-making and the implementation of adaptation strategies. In East Africa, RVF outbreaks are linked with abnormally high rainfall, and can be predicted up to 5 months in advance by modeling approaches using climatic and environmental parameters. However, the application of these models in West Africa remains unsatisfactory due to a lack of data for animal and human cases and differences in the dynamics of the disease emergence and the vector species involved in transmission. Models have been proposed for West Africa but they were restricted to rainfall impact analysis without a spatial dimension. In this study, we developed a mixed Bayesian statistical model to evaluate the effects of climatic and ecological determinants on the spatiotemporal dynamics of the two main vectors. Adult mosquito abundance data were generated from July to December every fortnight in 2005-2006 at 79 sites, including temporary ponds, bare soils, shrubby savannah, wooded savannah, steppes, and villages in the Barkédji area. The results demonstrate the importance of environmental factors and weather conditions for predicting mosquito abundance. The rainfall and minimum temperature were positively correlated with the abundance of Cx. poicilipes, whereas the maximum temperature had negative effects. The rainfall was negatively correlated with the abundance of Ae. vexans. After combining land cover classes, weather conditions, and vector abundance, our model was used to predict the areas and periods with the highest risks of vector pressure. This information could support decision

Population genetics of two key mosquito vectors of Rift Valley Fever virus reveals new insights into the changing disease outbreak patterns in Kenya.

Directory of Open Access Journals (Sweden)

David P Tchouassi

2014-12-01

Full Text Available Rift Valley fever (RVF outbreaks in Kenya have increased in frequency and range to include northeastern Kenya where viruses are increasingly being isolated from known (Aedes mcintoshi and newly-associated (Ae. ochraceus vectors. The factors contributing to these changing outbreak patterns are unclear and the population genetic structure of key vectors and/or specific virus-vector associations, in particular, are under-studied. By conducting mitochondrial and nuclear DNA analyses on >220 Kenyan specimens of Ae. mcintoshi and Ae. ochraceus, we uncovered high levels of vector complexity which may partly explain the disease outbreak pattern. Results indicate that Ae. mcintoshi consists of a species complex with one of the member species being unique to the newly-established RVF outbreak-prone northeastern region of Kenya, whereas Ae. ochraceus is a homogeneous population that appears to be undergoing expansion. Characterization of specimens from a RVF-prone site in Senegal, where Ae. ochraceus is a primary vector, revealed direct genetic links between the two Ae. ochraceus populations from both countries. Our data strongly suggest that unlike Ae. mcintoshi, Ae. ochraceus appears to be a relatively recent, single 'introduction' into Kenya. These results, together with increasing isolations from this vector, indicate that Ae. ochraceus will likely be of greater epidemiological importance in future RVF outbreaks in Kenya. Furthermore, the overall vector complexity calls into question the feasibility of mosquito population control approaches reliant on genetic modification.

Population Genetics of Two Key Mosquito Vectors of Rift Valley Fever Virus Reveals New Insights into the Changing Disease Outbreak Patterns in Kenya

Science.gov (United States)

Tchouassi, David P.; Bastos, Armanda D. S.; Sole, Catherine L.; Diallo, Mawlouth; Lutomiah, Joel; Mutisya, James; Mulwa, Francis; Borgemeister, Christian; Sang, Rosemary; Torto, Baldwyn

2014-01-01

Rift Valley fever (RVF) outbreaks in Kenya have increased in frequency and range to include northeastern Kenya where viruses are increasingly being isolated from known (Aedes mcintoshi) and newly-associated (Ae. ochraceus) vectors. The factors contributing to these changing outbreak patterns are unclear and the population genetic structure of key vectors and/or specific virus-vector associations, in particular, are under-studied. By conducting mitochondrial and nuclear DNA analyses on >220 Kenyan specimens of Ae. mcintoshi and Ae. ochraceus, we uncovered high levels of vector complexity which may partly explain the disease outbreak pattern. Results indicate that Ae. mcintoshi consists of a species complex with one of the member species being unique to the newly-established RVF outbreak-prone northeastern region of Kenya, whereas Ae. ochraceus is a homogeneous population that appears to be undergoing expansion. Characterization of specimens from a RVF-prone site in Senegal, where Ae. ochraceus is a primary vector, revealed direct genetic links between the two Ae. ochraceus populations from both countries. Our data strongly suggest that unlike Ae. mcintoshi, Ae. ochraceus appears to be a relatively recent, single 'introduction' into Kenya. These results, together with increasing isolations from this vector, indicate that Ae. ochraceus will likely be of greater epidemiological importance in future RVF outbreaks in Kenya. Furthermore, the overall vector complexity calls into question the feasibility of mosquito population control approaches reliant on genetic modification. PMID:25474018

Typhoid fever

Science.gov (United States)

Typhoid fever is an infection that causes diarrhea and a rash . It is most commonly caused due to ... in their stools for years, spreading the disease. Typhoid fever is common in developing countries. Most cases in ...

Fever in Infants and Children

Science.gov (United States)

... or higher that is unresponsive to fever-reducing medicine?YesNoDoes your child have a low-grade fever (up to 101°) ... fever, give your child a nonaspirin fever-reducing medicine. Call your child’s doctor after 24 hours if the fever continues ...

Recent characterization activities of Midway Valley as a potential repository surface facility site

International Nuclear Information System (INIS)

Gibson, J.D.; Wesling, J.R.; Swan, F.H.; Bullard, T.F.

1992-01-01

Midway Valley, located at the eastern base of Yucca Mountain, Nye County, Nevada, has been identified as a possible location for the surface facilities of a potential high-level nuclear-waste repository. This structural and topographic valley is bounded by two north- trending, down-to-the-west normal faults: the Paintbrush Canyon fault on the east and the Bow Ridge fault on the west. Surface and near-surface geological data have been acquired from Midway Valley during the past three years with particular emphasis on evaluating the existence of Quaternary faults. A detailed (1:6000) surficial geological map has been prepared based on interpretation of new and existing aerial photographs, field mapping, soil pits, and trenches. No evidence was found that would indicate displacement of these surficial deposits along previously unrecognized faults. However, given the low rates of Quaternary faulting and the extensive areas that are covered by late Pleistocene to Holocene deposits south of Sever Wash, Quaternary faulting between known faults cannot be precluded based on surface evidence alone. Middle to late Pleistocene alluvial fan deposits (Unit Q3) exist at or near the surface throughout Midway Valley. Confidence is increased that the potential for surface fault rupture in Midway Valley can be assessed by excavations that expose the deposits and soils associated with Unit Q3 or older units (middle Pleistocene or earlier)

Towards an Excursion Flora for Austria and all the Eastern Alps

Directory of Open Access Journals (Sweden)

Manfred A. Fischer

2018-02-01

Full Text Available This is on the one hand an announcement of the two-volume Fourth Edition of the Excursion Flora for Austria expanded by also including the remaining parts of the Eastern Alps (chapter 1, and on the other hand a rough survey of the flora of the Eastern Alps in connection with the main vegetation types (chapter 2. The geographical scope includes, besides Austria, the entire Eastern Alps from the Rhine valley in E Switzerland (Grisons to the Vipava valley in SW Slovenia. Volume 1 mainly contains comprehensive introductory chapters like introductions to plant morphology, taxonomy, and nomenclature, as well as a sketch of ecomorphology and habitat ecology, a survey of vegetation types (phytosociology and floristic peculiarities of the different natural regions, a rough history of floristic research, a detailed glossary including the meaning of epithets, etc., and drawings of several plant species characteristic of the flora covered. The structure of the keys concentrated in volume 2 is explained: besides the descriptive traits, they include for each taxon comprehensive ecological and plant geographical data, as well as information about Red Lists of the countries involved, plant uses, and taxonomical problems. Genus names are given not only in German, but also in the Romansh (Rumantsch Grischun, Italian, and Slovenian languages. In chapter 2, some important chorotypes including endemics are characterised, and an overview of floristic diversity (lists of exemplary taxa in accordance with the main and most characteristic vegetation types is presented.

Climate Teleconnections and Recent Patterns of Human and Animal Disease Outbreaks

Science.gov (United States)

Anyamba, Assaf; Linthicum, Kenneth J.; Small, Jennifer L.; Collins, Katherine M.; Tucker, Compton J.; Pak, Edwin W.; Britch, Seth C.; Eastman, James Ronald; Pinzon, Jorge E.; Russell, Kevin L.

2011-01-01

Recent clusters of outbreaks of mosquito-borne diseases (Rift Valley fever and chikungunya) in Africa and parts of the Indian Ocean islands illustrate how interannual climate variability influences the changing risk patterns of disease outbreaks. Extremes in rainfall (drought and flood) during the period 2004 - 2009 have privileged different disease vectors. Chikungunya outbreaks occurred during the severe drought from late 2004 to 2006 over coastal East Africa and the western Indian Ocean islands and in the later years India and Southeast Asia. The chikungunya pandemic was caused by a Central/East African genotype that appears to have been precipitated and then enhanced by global-scale and regional climate conditions in these regions. Outbreaks of Rift Valley fever occurred following excessive rainfall period from late 2006 to late 2007 in East Africa and Sudan, and then in 2008 - 2009 in Southern Africa. The shift in the outbreak patterns of Rift Valley fever from East Africa to Southern Africa followed a transition of the El Nino/Southern Oscillation (ENSO) phenomena from the warm El Nino phase (2006-2007) to the cold La Nina phase (2007-2009) and associated patterns of variability in the greater Indian Ocean basin that result in the displacement of the centres of above normal rainfall from Eastern to Southern Africa. Understanding the background patterns of climate variability both at global and regional scale and their impacts on ecological drivers of vector borne-diseases is critical in long-range planning of appropriate response and mitigation measures.

Dengue fever

African Journals Online (AJOL)

symptoms and research has been limited to studies ... severity and problems with vaccination (4). History of ... Americas in 1970s reduced the spread of dengue fever. After this .... Reiter P. Yellow fever and dengue: a threat to Europe? 9.

Predicting the mosquito species and vertebrate species involved in the theoretical transmission of Rift Valley fever virus in the United States.

Directory of Open Access Journals (Sweden)

Andrew J Golnar

2014-09-01

Full Text Available Rift Valley fever virus (RVFV is a mosquito-borne virus in the family Bunyaviridiae that has spread throughout continental Africa to Madagascar and the Arabian Peninsula. The establishment of RVFV in North America would have serious consequences for human and animal health in addition to a significant economic impact on the livestock industry. Published and unpublished data on RVFV vector competence, vertebrate host competence, and mosquito feeding patterns from the United States were combined to quantitatively implicate mosquito vectors and vertebrate hosts that may be important to RVFV transmission in the United States. A viremia-vector competence relationship based on published mosquito transmission studies was used to calculate a vertebrate host competence index which was then combined with mosquito blood feeding patterns to approximate the vector and vertebrate amplification fraction, defined as the relative contribution of the mosquito or vertebrate host to pathogen transmission. Results implicate several Aedes spp. mosquitoes and vertebrates in the order Artiodactyla as important hosts for RVFV transmission in the U.S. Moreover, this study identifies critical gaps in knowledge which would be necessary to complete a comprehensive analysis identifying the different contributions of mosquitoes and vertebrates to potential RVFV transmission in the U.S. Future research should focus on (1 the dose-dependent relationship between viremic exposure and the subsequent infectiousness of key mosquito species, (2 evaluation of vertebrate host competence for RVFV among North American mammal species, with particular emphasis on the order Artiodactyla, and (3 identification of areas with a high risk for RVFV introduction so data on local vector and host populations can help generate geographically appropriate amplification fraction estimates.

Predicting the mosquito species and vertebrate species involved in the theoretical transmission of Rift Valley fever virus in the United States.

Science.gov (United States)

Golnar, Andrew J; Turell, Michael J; LaBeaud, A Desiree; Kading, Rebekah C; Hamer, Gabriel L

2014-09-01

Rift Valley fever virus (RVFV) is a mosquito-borne virus in the family Bunyaviridiae that has spread throughout continental Africa to Madagascar and the Arabian Peninsula. The establishment of RVFV in North America would have serious consequences for human and animal health in addition to a significant economic impact on the livestock industry. Published and unpublished data on RVFV vector competence, vertebrate host competence, and mosquito feeding patterns from the United States were combined to quantitatively implicate mosquito vectors and vertebrate hosts that may be important to RVFV transmission in the United States. A viremia-vector competence relationship based on published mosquito transmission studies was used to calculate a vertebrate host competence index which was then combined with mosquito blood feeding patterns to approximate the vector and vertebrate amplification fraction, defined as the relative contribution of the mosquito or vertebrate host to pathogen transmission. Results implicate several Aedes spp. mosquitoes and vertebrates in the order Artiodactyla as important hosts for RVFV transmission in the U.S. Moreover, this study identifies critical gaps in knowledge which would be necessary to complete a comprehensive analysis identifying the different contributions of mosquitoes and vertebrates to potential RVFV transmission in the U.S. Future research should focus on (1) the dose-dependent relationship between viremic exposure and the subsequent infectiousness of key mosquito species, (2) evaluation of vertebrate host competence for RVFV among North American mammal species, with particular emphasis on the order Artiodactyla, and (3) identification of areas with a high risk for RVFV introduction so data on local vector and host populations can help generate geographically appropriate amplification fraction estimates.

Predominance of genotype 1.1 and emergence of genotype 2.2 classical swine fever viruses in north-eastern region of India.

Science.gov (United States)

Roychoudhury, P; Sarma, D K; Rajkhowa, S; Munir, M; Kuchipudi, S V

2014-08-01

Classical swine fever (CSF) is a highly contagious and the most important disease of pigs worldwide.CSF is enzootic in pig herds in India and continues to cause huge economic losses to pig farmers. Nearly 40% of the total pig population of India is present in the north-eastern (NE) states where pig husbandry plays an important role in the socio-economic development. Pigs reared in the backyards are the only source of livelihood for a majority of poor tribal population in the region. Hardly any CSF vaccination is currently being undertaken in the unorganized pig farming in the NE region due to economic reasons and vaccine unavailability. A thorough understanding of the current epidemiological status of CSF is essential for the effective control of the disease in the NE region. Hence, we carried out molecular characterization of CSFV isolates from field outbreaks during 2011-2012 in the entire north-eastern region of India to establish the genetic groups of prevalent CSF viruses in the region. A total of 17 CSFV isolates obtained from different parts of the NE region were characterized by comparing the sequences of three partial genomic regions of the virus, that is 150 nt of 5' UTR, 190 nt of E2 and 409 nt of NS5B. Of the 17 CSFV isolates, 15 isolates belonged to 1.1 (88.2%) and two isolates (11.8%) belonged to 2.2 subgenogroup. The genogroup 2.2 CSFV were associated with outbreaks in Arunachal Pradesh that shares international borders with Bhutan, Myanmar and China. Genogroup 2.2 CSFV isolated in the present study shared high level of sequence similarity with 2.2 viruses form China, raising the possibility of virus incursion from this region. In summary, we found a continued predominance of 1.1 subgroup and an emergence of 2.2 subgroup CSFV in NE region of India. © 2014 Blackwell Verlag GmbH.

Human rickettsioses in the Batna area, eastern Algeria.

Science.gov (United States)

Mokrani, Khamsa; Tebbal, Soraya; Raoult, Didier; Fournier, Pierre-Edouard

2012-12-01

In order to investigate the prevalence of rickettsioses in febrile exanthemas in eastern Algeria, we conducted a prospective serological analysis of all patients presenting with this clinical picture at the Infectious Diseases Department in the Batna Hospital from January 2000 to September 2006. One hundred and eight adult patients were included in the study, 46% of whom younger than 25 years, and 72.5% were admitted from May to September. Patients were tested for antibodies to Rickettsia conorii conorii, R. conorii israelensis, R. aeschlimannii, R. felis, R. sibirica mongolitimonae, R. africae, R. massiliae, R. typhi, and R. prowazekii using microimmunofluorescence and Western blot as confirmation procedure. Both methods confirmed the diagnosis of Mediterranean spotted fever in 5 patients (4.6%), flea spotted fever in 2 patients (1.9%), and R. aeschlimannii infection in 2 patients (1.9%). In addition, 4 patients were diagnosed as having murine typhus (3.7%) and one with epidemic typhus (0.9%). To the best of our knowledge, this is the first report of R. felis infection and R. aeschlimannii infection in Algeria. In conclusion, at least 5 different kinds of rickettsiosis coexist in eastern Algeria and, being responsible for 13% of cases of febrile exanthemas, should be considered among major causes of this clinical picture in this area. In addition, we emphasize the high incidence of typhus group rickettioses, including epidemic typhus, in this area. Copyright © 2012 Elsevier GmbH. All rights reserved.

Ethno-botanical study of medicinal plants of Paddar Valley of Jammu and Kashmir, India.

Science.gov (United States)

Gupta, Sushil Kumar; Sharma, O M Prakash; Raina, Narinder Singh; Sehgal, Sandeep

2013-01-01

The Paddar Valley, historically known as Sapphire Valley situated in Kishtwar district, is a prime landmark in the Jammu region of J&K state and is known for its rich cultural and plant diversity because of diverse habitats such as rivers, streams, meadows and steep mountain slopes. The area is located in the dry temperate region comprising typical vegetation which disappears completely on the eastern slopes, dominated by a variety of economical species which play an important role in the rural life. The inhabitants are dependent on plant resources for food, fuel, timber, shelter, fodder/forage, household articles and traditional medicines in treating diseases like malaria, cancer, gastro-intestinal ailments, etc. This paper deals with the observations on traditional therapeutic application by the inhabitants of Paddar Valley. The ethno-botanical information on medicinal plants would not only be useful in conservation of traditional cultures and biodiversity but also community health care and drug development. Exploration survey in Paddar Valley has revealed that people collect and sell these medicinal species through local intermediaries / contractors to earn their livelihood. But the scientific cultivation and appropriate post-harvest management would improve employment opportunity and income of local farmers in the region.

Preliminary gravity and magnetic models across Midway Valley and Yucca Wash, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Ponce, D.A.; Langenheim, V.E.

1994-01-01

Detailed gravity and ground magnetic data collected along ten traverses across Midway Valley and Yucca Wash on the eastern flank of Yucca Mountain in southwest Nevada are interpreted. These data were collected as part of an effort to evaluate faulting in the vicinity of proposed surface facilities for a potential nuclear waste repository at Yucca Mountain. Geophysical data show that Midway Valley is bounded by large gravity and magnetic anomalies associated with the Bow Ridge and Paintbrush Canyon faults, on the west side of Exile Hill and on the west flank of Fran Ridge, respectively. In addition, Midway Valley itself is characterized by a number of small-amplitude anomalies that probably reflect small-scale faulting beneath Midway Valley. Gravity and magnetic data across the northwest trending Yucca Wash and the inferred Yucca Wash fault indicate no major vertical offsets greater than 100 m using a density contrast of 0.2 to 0.3 g/cm 3 along the proposed Yucca Wash fault. In addition, a broad magnetic high coincides with the approximate location of the hydrologic gradient and probably reflects moderately magnetic Topopah Spring Tuff or lavas in the Calico Hills Formation

West Nile virus circulation in South-Eastern Romania, 2011 to 2013.

Science.gov (United States)

Dinu, S; Cotar, A I; Pănculescu-Gătej, I R; Fălcuţă, E; Prioteasa, F L; Sîrbu, A; Oprişan, G; Bădescu, D; Reiter, P; Ceianu, C S

2015-05-21

Lineage 2 West Nile virus (WNV), previously found only in sub-Saharan Africa and Madagascar, was identified in Hungary in 2004 and has rapidly expanded in Europe in the past decade. Following a significant outbreak of West Nile fever with neurological cases caused by lineage 1 WNV in Romania in 1996, scattered cases have been recorded in the south-east of the country in each transmission season. Another outbreak, affecting a larger area and caused by lineage 2 WNV, was recorded in 2010. We analysed human sera from neuroinvasive West Nile fever cases and mosquitoes, sampled in south-eastern Romania between 2011 and 2013, for the presence of WNV genome, and obtained partial NS5 and envelope glycoprotein sequences. Human- and mosquito-derived WNV sequences were highly similar (99%) to Volgograd 2007 lineage 2 WNV and differed from isolates previously detected in central and southern Europe. WNV was detected in one pool of Culex pipiens s.l. males, documenting vertical transmission. Lineage 4 WNV, of unknown pathogenicity to mammals, was found in the amphibian-feeding mosquito Uranotaenia unguiculata from the Danube Delta. Our results present molecular evidence for the maintenance of the same isolates of Volgograd 2007-like lineage 2 WNV in south-eastern Romania between 2011 and 2013.

Fever with Rashes.

Science.gov (United States)

Soman, Letha

2018-07-01

Fever with rashes is one of the commonest clinical problems a general practitioner or pediatrician has to face in day-to-day clinical practice. It can be a mild viral illness or a life-threatening illness like meningococcemia or Dengue hemorrhagic fever or it can be one with a lifelong consequence like Kawasaki disease. It is very important to arrive at a clinical diagnosis as early as possible with the minimum investigational facilities. The common causes associated with fever and rashes are infections, viral followed by other infections. There can be so many non-infectious causes also for fever and rashes like auto immune diseases, drug allergies etc. The type of rashes, their appearance in relation to the fever and pattern of spread to different parts of body and the disappearance, all will help in making a diagnosis. Often the diagnosis is clinical. In certain situations laboratory work up becomes essential.

Geomorphology and Geology of the Southwestern Margaritifer Sinus and Argyre Regions of Mars. Part 3: Valley Types and Distribution

Science.gov (United States)

Parker, T. J.; Pieri, D. C.

1985-01-01

Three major valley tapes were identified in the SW Margaritefer Sinus and Argyre regions. Two are restricted to specific geologic units while the third is independent of the geology. The first type (the small valley networks) are found within the channeled and subdued plains unit in the eastern half of the map, in the grooved and channeled plains unit north of Nirgal Vallis, and in scattered instances in the cratered plateau unit north of Argyre. The even smaller valleys just inside Argyre's rim and on the inner slopes of many large craters are not directly related to the processes which formed the small valleys but are a result, instead, of post-impact modification of the crater walls. The second type of valley network is represented by Nirgal Vallis and the similar, shorter continuation of it to the west. This type is found only in the smooth plains material west of Uzboi Vallis in the map area. The third type of valley network is that of the Uzbol-Holden-Ladon valles system. This system is related to catastrophic outflow from Argyre Basin and is topographically rather than geologically controlled.

Rocky Mountain spotted fever

Science.gov (United States)

... spotted fever on the foot Rocky Mountain spotted fever, petechial rash Antibodies Deer and dog tick References McElligott SC, Kihiczak GG, Schwartz RA. Rocky Mountain spotted fever and other rickettsial infections. In: Lebwohl MG, Heymann ...

Birds of the St. Croix River valley: Minnesota and Wisconsin

Science.gov (United States)

Faanes, Craig A.

1981-01-01

The St. Croix River Valley encompasses nearly 11,550 km2 in east-central Minnesota and northwestern Wisconsin. A wide range of habitats are available for birds including upland oak, lowland deciduous, maple-basswood, lowland and upland coniferous forests, natural basin wetlands, and grasslands. Situated in the north-central region of the United States, the valley is a biological 'crossroads' for many species. Because of the mixed affinities of plant communities, the valley includes the northern and southern range limits for a number of species. Also, because the valley lies near the forest-prairie transition zone, many typical western breeding species (e.g. pintail, western meadowlark, yellow-headed blackbird) breed in proximity to typical eastern species such as tufted titmouse, eastern meadowlark, and cardinal. From 1966 to 1980, I conducted extensive surveys of avian distribution and abundance in the St. Croix River Valley. I have supplemented the results of these surveys with published and unpublished observations contributed by many ornithologists. These additional data include compilations from Christmas Bird Counts sponsored by the National Audubon Society and from the Breeding Bird Survey coordinated by the U.S. Fish and Wildlife Service. Three hundred fourteen species have been recorded in the study area; data are presented on the migration period, nesting season distribution, winter distribution, relative abundance, and habitat use of each species. Recognizing the uniqueness of the area, and its importance not only to wildlife but also to man, the U.S. Congress designated the St. Croix a National Scenic Riverway. This action provided a considerable degree of protection to lands along and directly adjacent to the river. Unfortunately, no similar legal measure exists to protect lands away from the river. With the exception of the northern quarter of the St. Croix River Valley, agricultural interests have made significant inroads into the habitat base. The

Valley-dependent band structure and valley polarization in periodically modulated graphene

Science.gov (United States)

Lu, Wei-Tao

2016-08-01

The valley-dependent energy band and transport property of graphene under a periodic magnetic-strained field are studied, where the time-reversal symmetry is broken and the valley degeneracy is lifted. The considered superlattice is composed of two different barriers, providing more degrees of freedom for engineering the electronic structure. The electrons near the K and K' valleys are dominated by different effective superlattices. It is found that the energy bands for both valleys are symmetric with respect to ky=-(AM+ξ AS) /4 under the symmetric superlattices. More finite-energy Dirac points, more prominent collimation behavior, and new crossing points are found for K' valley. The degenerate miniband near the K valley splits into two subminibands and produces a new band gap under the asymmetric superlattices. The velocity for the K' valley is greatly renormalized compared with the K valley, and so we can achieve a finite velocity for the K valley while the velocity for the K' valley is zero. Especially, the miniband and band gap could be manipulated independently, leading to an increase of the conductance. The characteristics of the band structure are reflected in the transmission spectra. The Dirac points and the crossing points appear as pronounced peaks in transmission. A remarkable valley polarization is obtained which is robust to the disorder and can be controlled by the strain, the period, and the voltage.

Mechanistic Insight into the Host Transcription Inhibition Function of Rift Valley Fever Virus NSs and Its Importance in Virulence.

Science.gov (United States)

Terasaki, Kaori; Ramirez, Sydney I; Makino, Shinji

2016-10-01

Rift Valley fever virus (RVFV), a member of the genus Phlebovirus within the family Bunyaviridae, causes periodic outbreaks in livestocks and humans in countries of the African continent and Middle East. RVFV NSs protein, a nonstructural protein, is a major virulence factor that exhibits several important biological properties. These include suppression of general transcription, inhibition of IFN-β promoter induction and degradation of double-stranded RNA-dependent protein kinase R. Although each of these biological functions of NSs are considered important for countering the antiviral response in the host, the individual contributions of these functions towards RVFV virulence remains unclear. To examine this, we generated two RVFV MP-12 strain-derived mutant viruses. Each carried mutations in NSs that specifically targeted its general transcription inhibition function without affecting its ability to degrade PKR and inhibit IFN-β promoter induction, through its interaction with Sin3-associated protein 30, a part of the repressor complex at the IFN-β promoter. Using these mutant viruses, we have dissected the transcription inhibition function of NSs and examined its importance in RVFV virulence. Both NSs mutant viruses exhibited a differentially impaired ability to inhibit host transcription when compared with MP-12. It has been reported that NSs suppresses general transcription by interfering with the formation of the transcription factor IIH complex, through the degradation of the p62 subunit and sequestration of the p44 subunit. Our study results lead us to suggest that the ability of NSs to induce p62 degradation is the major contributor to its general transcription inhibition property, whereas its interaction with p44 may not play a significant role in this function. Importantly, RVFV MP-12-NSs mutant viruses with an impaired general transcription inhibition function showed a reduced cytotoxicity in cell culture and attenuated virulence in young mice

Yellow fever: epidemiology and prevention.

Science.gov (United States)

Barnett, Elizabeth D

2007-03-15

Yellow fever continues to occur in regions of Africa and South America, despite the availability of effective vaccines. Recently, some cases of severe neurologic disease and multiorgan system disease have been described in individuals who received yellow fever vaccine. These events have focused attention on the need to define criteria for judicious use of yellow fever vaccine and to describe the spectrum of adverse events that may be associated with yellow fever vaccine. Describing host factors that would increase risk of these events and identifying potential treatment modalities for yellow fever and yellow fever vaccine-associated adverse events are subjects of intense investigation.

Evaluation of the Location and Recency of Faulting Near Prospective Surface Facilities in Midway Valley, Nye County, Nevada

Science.gov (United States)

Swan, F.H.; Wesling, J.R.; Angell, M.M.; Thomas, A.P.; Whitney, J.W.; Gibson, J.D.

2001-01-01

Evaluation of surface faulting that may pose a hazard to prospective surface facilities is an important element of the tectonic studies for the potential Yucca Mountain high-level radioactive waste repository in southwestern Nevada. For this purpose, a program of detailed geologic mapping and trenching was done to obtain surface and near-surface geologic data that are essential for determining the location and recency of faults at a prospective surface-facilities site located east of Exile Hill in Midway Valley, near the eastern base of Yucca Mountain. The dominant tectonic features in the Midway Valley area are the north- to northeast-trending, west-dipping normal faults that bound the Midway Valley structural block-the Bow Ridge fault on the west side of Exile Hill and the Paint-brush Canyon fault on the east side of the valley. Trenching of Quaternary sediments has exposed evidence of displacements, which demonstrate that these block-bounding faults repeatedly ruptured the surface during the middle to late Quaternary. Geologic mapping, subsurface borehole and geophysical data, and the results of trenching activities indicate the presence of north- to northeast-trending faults and northwest-trending faults in Tertiary volcanic rocks beneath alluvial and colluvial sediments near the prospective surface-facilities site. North to northeast-trending faults include the Exile Hill fault along the eastern base of Exile Hill and faults to the east beneath the surficial deposits of Midway Valley. These faults have no geomorphic expression, but two north- to northeast-trending zones of fractures exposed in excavated profiles of middle to late Pleistocene deposits at the prospective surface-facilities site appear to be associated with these faults. Northwest-trending faults include the West Portal and East Portal faults, but no disruption of Quaternary deposits by these faults is evident. The western zone of fractures is associated with the Exile Hill fault. The eastern

Evaluation of the location and recency of faulting near prospective surface facilities in Midway Valley, Nye County, Nevada

Energy Technology Data Exchange (ETDEWEB)

Swan, F.H.; Wesling, J.R.; Angell, M.M.; Thomas, A.P.; Whitney, J.W.; Gibson, J.D.

2002-01-17

Evaluation of surface faulting that may pose a hazard to prospective surface facilities is an important element of the tectonic studies for the potential Yucca Mountain high-level radioactive waste repository in southwestern Nevada. For this purpose, a program of detailed geologic mapping and trenching was done to obtain surface and near-surface geologic data that are essential for determining the location and recency of faults at a prospective surface-facilities site located east of Exile Hill in Midway Valley, near the eastern base of Yucca Mountain. The dominant tectonic features in the Midway Valley area are the north- to northeast-trending, west-dipping normal faults that bound the Midway Valley structural block-the Bow Ridge fault on the west side of Exile Hill and the Paint-brush Canyon fault on the east side of the valley. Trenching of Quaternary sediments has exposed evidence of displacements, which demonstrate that these block-bounding faults repeatedly ruptured the surface during the middle to late Quaternary. Geologic mapping, subsurface borehole and geophysical data, and the results of trenching activities indicate the presence of north- to northeast-trending faults and northwest-trending faults in Tertiary volcanic rocks beneath alluvial and colluvial sediments near the prospective surface-facilities site. North to northeast-trending faults include the Exile Hill fault along the eastern base of Exile Hill and faults to the east beneath the surficial deposits of Midway Valley. These faults have no geomorphic expression, but two north- to northeast-trending zones of fractures exposed in excavated profiles of middle to late Pleistocene deposits at the prospective surface-facilities site appear to be associated with these faults. Northwest-trending faults include the West Portal and East Portal faults, but no disruption of Quaternary deposits by these faults is evident. The western zone of fractures is associated with the Exile Hill fault. The eastern

Evaluation of the location and recency of faulting near prospective surface facilities in Midway Valley, Nye County, Nevada

International Nuclear Information System (INIS)

Swan, F.H.; Wesling, J.R.; Angell, M.M.; Thomas, A.P.; Whitney, J.W.; Gibson, J.D.

2002-01-01

Evaluation of surface faulting that may pose a hazard to prospective surface facilities is an important element of the tectonic studies for the potential Yucca Mountain high-level radioactive waste repository in southwestern Nevada. For this purpose, a program of detailed geologic mapping and trenching was done to obtain surface and near-surface geologic data that are essential for determining the location and recency of faults at a prospective surface-facilities site located east of Exile Hill in Midway Valley, near the eastern base of Yucca Mountain. The dominant tectonic features in the Midway Valley area are the north- to northeast-trending, west-dipping normal faults that bound the Midway Valley structural block-the Bow Ridge fault on the west side of Exile Hill and the Paint-brush Canyon fault on the east side of the valley. Trenching of Quaternary sediments has exposed evidence of displacements, which demonstrate that these block-bounding faults repeatedly ruptured the surface during the middle to late Quaternary. Geologic mapping, subsurface borehole and geophysical data, and the results of trenching activities indicate the presence of north- to northeast-trending faults and northwest-trending faults in Tertiary volcanic rocks beneath alluvial and colluvial sediments near the prospective surface-facilities site. North to northeast-trending faults include the Exile Hill fault along the eastern base of Exile Hill and faults to the east beneath the surficial deposits of Midway Valley. These faults have no geomorphic expression, but two north- to northeast-trending zones of fractures exposed in excavated profiles of middle to late Pleistocene deposits at the prospective surface-facilities site appear to be associated with these faults. Northwest-trending faults include the West Portal and East Portal faults, but no disruption of Quaternary deposits by these faults is evident. The western zone of fractures is associated with the Exile Hill fault. The eastern

Comparison of sampling techniques for Rift Valley Fever virus potential vectors, Aedes aegypti and Culex pipiens complex, in Ngorongoro District in northern Tanzania.

Science.gov (United States)

Mweya, Clement N; Kimera, Sharadhuli I; Karimuribo, Esron D; Mboera, Leonard E G

2013-07-01

We investigated mosquito sampling techniques with two types of traps and attractants at different time for trapping potential vectors for Rift Valley Fever virus. The study was conducted in six villages in Ngorongoro district in Tanzania from September to October 2012. A total of 1814 mosquitoes were collected, of which 738 were collected by CDC light traps and 1076 by Mosquito Magnet trapping technique. Of the collected mosquitoes, 12.46% (N = 226) were Aedes aegypti and 87.54% (N = 1588) were Culex pipiens complex. More mosquitoes were collected outdoors using Mosquito Magnets baited with octenol attractant, 36.38% (N =660) followed by indoor trapping using CDC light traps without attractant, 29.60% (N = 537). Most of Ae. aegypti mosquitoes were collected outdoor using Mosquito Magnets, 95% (N = 214) whereas Cx. pipiens complex were trapped both indoor using CDC light traps without attractant and outdoors using both CDC light traps baited with carbon dioxide (CO2) sachets and Mosquito Magnets. Analysis on the differences in abundance of mosquitoes trapped by different techniques using Generalized Linear Models was statistically significance at p-value < 0.05 for both species. Three hours mosquito collections show differing patterns in activity, most Ae. aegypti species were collected primarily during the first and last quarters of the day. Cx pipiens complex was active throughout the night, early evening and early morning then decreased markedly during the day time. The results presented in this paper emphasize the possibility of using Mosquito Magnets in order to efficiently capture these potential RVF vectors.

Early Holocene (8.6 ka) rock avalanche deposits, Obernberg valley (Eastern Alps): Landform interpretation and kinematics of rapid mass movement.

Science.gov (United States)

Ostermann, Marc; Sanders, Diethard; Ivy-Ochs, Susan; Alfimov, Vasily; Rockenschaub, Manfred; Römer, Alexander

2012-10-15

In the Obernberg valley, the Eastern Alps, landforms recently interpreted as moraines are re-interpreted as rock avalanche deposits. The catastrophic slope failure involved an initial rock volume of about 45 million m³, with a runout of 7.2 km over a total vertical distance of 1330 m (fahrböschung 10°). 36 Cl surface-exposure dating of boulders of the avalanche mass indicates an event age of 8.6 ± 0.6 ka. A 14 C age of 7785 ± 190 cal yr BP of a palaeosoil within an alluvial fan downlapping the rock avalanche is consistent with the event age. The distal 2 km of the rock-avalanche deposit is characterized by a highly regular array of transverse ridges that were previously interpreted as terminal moraines of Late-Glacial. 'Jigsaw-puzzle structure' of gravel to boulder-size clasts in the ridges and a matrix of cataclastic gouge indicate a rock avalanche origin. For a wide altitude range the avalanche deposit is preserved, and the event age of mass-wasting precludes both runout over glacial ice and subsequent glacial overprint. The regularly arrayed transverse ridges thus were formed during freezing of the rock avalanche deposits.

Virgin Valley opal district, Humboldt County, Nevada

Science.gov (United States)

Staatz, Mortimer Hay; Bauer, Herman L.

1951-01-01

The Virgin Valley opal district, Humboldt County, Nevada, is near the Oregon-Nevada border in the Sheldon Game Refuge. Nineteen claims owned by Jack and Toni Crane were examined, sampled, and tested radiometrically for uranium. Numerous discontinuous layers of opal are interbedded with a gently-dipping series of vitric tuff and ash which is at least 300 ft thick. The tuff and ash are capped by a dark, vesicular basalt in the eastern part of the area and by a thin layer of terrace qravels in the area along the west side of Virgin Valley. Silicification of the ash and tuff has produced a rock that ranges from partly opalized rock that resembles silicified shale to completely altered rock that is entirely translucent, and consists of massive, brown and pale-green opal. Carnotite, the only identified uranium mineral, occurs as fracture coatings or fine layers in the opal; in places, no uranium minerals are visible in the radioactive opal. The opal layers are irregular in extent and thickness. The exposed length of the layers ranges from 8 to 1, 200 ft or more, and the thickness of the layers ranges from 0. 1 to 3. 9 ft. The uranium content of each opal layer, and of different parts of the same layer, differs widely. On the east side of Virgin Valley four of the seven observed opal layers, nos. 3, 4, 5, and 7, are more radioactive than the average; and the uranium content ranges from 0. 002 to 0. 12 percent. Two samples, taken 5 ft apart across opal layer no. 7, contained 0. 003 and 0. -049 percent uranium. On the west side of the valley only four of the fifteen observed opal layers, nos; 9, , 10, 14, and 15, are more radioactive than the average; and the uranium content ranges from 0. 004 to 0. 047 percent. Material of the highest grade was found in a small discontinuous layer of pale-green opal (no. 4) on the east side of Virgin Valley. The grade of this layer ranged from 0. 027 to 0. 12 percent uranium.

Occurrence of PAH in the seasonal snowpack of the Eastern Italian Alps

Energy Technology Data Exchange (ETDEWEB)

Gabrieli, Jacopo [Chemical Science Department, University of Padova, via Marzolo 1/A, 35100 Padua (Italy); Environmental Protection Agency of Veneto (ARPAV), Department of Belluno, via Tomea 5, 32100 Belluno (Italy); Department of Environmental Sciences, University Ca' Foscari of Venice, Dorsoduro 2137, 30123 Venice (Italy); Decet, Fabio [Environmental Protection Agency of Veneto (ARPAV), Department of Belluno, via Tomea 5, 32100 Belluno (Italy); Luchetta, Alberto [Environmental Protection Agency of Veneto (ARPAV), Department of Belluno, via Tomea 5, 32100 Belluno (Italy); Arabba Avalanche Center, Environmental Protection Agency of Veneto (ARPAV), via Pradat 5, 32020 Livinallongo del Col di Lana, Belluno (Italy); Valt, Mauro [Arabba Avalanche Center, Environmental Protection Agency of Veneto (ARPAV), via Pradat 5, 32020 Livinallongo del Col di Lana, Belluno (Italy); Pastore, Paolo [Chemical Science Department, University of Padova, via Marzolo 1/A, 35100 Padua (Italy); Barbante, Carlo, E-mail: barbante@unive.i [Department of Environmental Sciences, University Ca' Foscari of Venice, Dorsoduro 2137, 30123 Venice (Italy); Institute for the Dynamics of Environmental Processes - CNR, University of Venice, Dorsoduro 2137, 30123 Venice (Italy)

2010-10-15

PAH concentrations have been determined in 47 seasonal snowpack samples collected in the Valbelluna valley and in the Bellunesi Dolomites National Park, in the Italian North-Eastern Alps, during the winter of 2005. The {Sigma}PAH concentration in high-altitude alpine sites (above 1700 m) was 32 {+-} 20 ng/kg while in valley bottom urban areas it was 165 {+-} 54 ng/kg with maximum values of 290 ng/kg. The GIS mapping technique was employed to produce a PAH spatial distribution. The urbanized Valbelluna valley, and in particular the SW part, had the highest accumulation of all PAH, with values an order of magnitude more than those in rural and alpine areas. This behaviour is consistent with urban air quality data, and is due to geo-morphological and meteorological factors such as the deeper shape of the valley at the position of the town of Feltre and the low altitude of the boundary layer during the winter season. - PAH concentrations determined in seasonal snow represent an integration of the winter depositions and can be used to evaluate the pollution levels in an Alpine region.

Occurrence of PAH in the seasonal snowpack of the Eastern Italian Alps

International Nuclear Information System (INIS)

Gabrieli, Jacopo; Decet, Fabio; Luchetta, Alberto; Valt, Mauro; Pastore, Paolo; Barbante, Carlo

2010-01-01

PAH concentrations have been determined in 47 seasonal snowpack samples collected in the Valbelluna valley and in the Bellunesi Dolomites National Park, in the Italian North-Eastern Alps, during the winter of 2005. The ΣPAH concentration in high-altitude alpine sites (above 1700 m) was 32 ± 20 ng/kg while in valley bottom urban areas it was 165 ± 54 ng/kg with maximum values of 290 ng/kg. The GIS mapping technique was employed to produce a PAH spatial distribution. The urbanized Valbelluna valley, and in particular the SW part, had the highest accumulation of all PAH, with values an order of magnitude more than those in rural and alpine areas. This behaviour is consistent with urban air quality data, and is due to geo-morphological and meteorological factors such as the deeper shape of the valley at the position of the town of Feltre and the low altitude of the boundary layer during the winter season. - PAH concentrations determined in seasonal snow represent an integration of the winter depositions and can be used to evaluate the pollution levels in an Alpine region.

Capacitively Coupled Resistivity Survey of Selected Irrigation Canals Within the North Platte River Valley, Western Nebraska and Eastern Wyoming, 2004 and 2007-2009

Science.gov (United States)

Burton, Bethany L.; Johnson, Michaela R.; Vrabel, Joseph; Imig, Brian H.; Payne, Jason; Tompkins, Ryan E.

2009-01-01

Due to water resources of portions of the North Platte River basin being designated as over-appropriated by the State of Nebraska Department of Natural Resources (DNR), the North Platte Natural Resources District (NPNRD), in cooperation with the DNR, is developing an Integrated Management Plan (IMP) for groundwater and surface water in the NPNRD. As part of the IMP, a three-dimensional numerical finite difference groundwater-flow model is being developed to evaluate the effectiveness of using leakage of water from selected irrigation canal systems to manage groundwater recharge. To determine the relative leakage potential of the upper 8 m of the selected irrigation canals within the North Platte River valley in western Nebraska and eastern Wyoming, the U.S. Geological Survey performed a land-based capacitively coupled (CC) resistivity survey along nearly 630 km of 13 canals and 2 laterals in 2004 and from 2007 to 2009. These 13 canals were selected from the 27 irrigation canals in the North Platte valley due to their location, size, irrigated area, and relation to the active North Platte valley flood plain and related paleochannels and terrace deposits where most of the saturated thickness in the alluvium exists. The resistivity data were then compared to continuous cores at 62 test holes down to a maximum depth of 8 m. Borehole electrical conductivity (EC) measurements at 36 of those test holes were done to correlate resistivity values with grain sizes in order to determine potential vertical leakage along the canals as recharge to the underlying alluvial aquifer. The data acquired in 2004, as well as the 25 test hole cores from 2004, are presented elsewhere. These data were reprocessed using the same updated processing and inversion algorithms used on the 2007 through 2009 datasets, providing a consistent and complete dataset for all collection periods. Thirty-seven test hole cores and borehole electrical conductivity measurements were acquired based on the 2008

Mapping of zones potentially occupied by Aedes vexans and Culex poicilipes mosquitoes, the main vectors of Rift Valley fever in Senegal

Directory of Open Access Journals (Sweden)

Yves M. Tourre

2008-11-01

Full Text Available A necessary condition for Rift Valley fever (RVF emergence is the presence of Aedes (Aedimorphus vexans and Culex (Culex poicilipes mosquitoes carrying the arbovirus and responsible for the infection. This paper presents a detailed mapping in the Sahelian region of Senegal of zones potentially occupied by these mosquitoes (ZPOMs whose population density is directly linked to ecozones in the vicinity of small ponds. The vectors habitats and breeding sites have been characterized through an integrated approach combining remote sensing technology, geographical information systems, geographical positioning systems and field observations for proper geo-referencing. From five SPOT-5 images (~10 m spatial resolution with appropriate channels, a meridional composite transect of 290 x 60 km was first constructed at the height of the summer monsoon. Subsequent ZPOMs covered major ecozones from north to south with different hydrological environments and different patterns pond distributions. It was found that an overall area of 12,817 ha ± 10% (about 0.8% of the transect is occupied by ponds with an average ZPOM 17 times larger than this (212,813 ha ± 10% or about 14% of the transect. By comparing the very humid year of 2003 with 2006 which had just below normal rainfall, the ZPOMs inter-annual variability was analyzed in a sandy-clayey ecozone with an important hydrofossil riverbed within the Ferlo region of Senegal. Very probably contributing to an increased abundance of vectors by the end of August 2003, it was shown that the aggregate pond area was already about 22 times larger than in August 2006, corresponding to an approximately five times larger total ZPOM. The results show the importance of pin-pointing small ponds (sizes down to 0.1 ha and their geographical distribution in order to assess animal exposure to the RVF vectors.

Mutation of adjacent cysteine residues in the NSs protein of Rift Valley fever virus results in loss of virulence in mice.

Science.gov (United States)

Monteiro, Gaby E R; Jansen van Vuren, Petrus; Wichgers Schreur, Paul J; Odendaal, Lieza; Clift, Sarah J; Kortekaas, Jeroen; Paweska, Janusz T

2018-04-02

The NSs protein encoded by the S segment of Rift Valley fever virus (RVFV) is the major virulence factor, counteracting the host innate antiviral defence. It contains five highly conserved cysteine residues at positions 39, 40, 149, 178 and 194, which are thought to stabilize the tertiary and quaternary structure of the protein. Here, we report significant differences between clinical, virological, histopathological and host gene responses in BALB/c mice infected with wild-type RVFV (wtRVFV) or a genetic mutant having a double cysteine-to-serine substitution at residues 39 and 40 of the NSs protein (RVFV-C39S/C40S). Mice infected with the wtRVFV developed a fatal acute disease; characterized by high levels of viral replication, severe hepatocellular necrosis, and massive up-regulation of transcription of genes encoding type I and -II interferons (IFN) as well as pro-apoptotic and pro-inflammatory cytokines. The RVFV-C39S/C40S mutant did not cause clinical disease and its attenuated virulence was consistent with virological, histopathological and host gene expression findings in BALB/c mice. Clinical signs in mice infected with viruses containing cysteine-to-serine substitutions at positions 178 or 194 were similar to those occurring in mice infected with the wtRVFV, while a mutant containing a substitution at position 149 caused mild, non-fatal disease in mice. As mutant RVFV-C39S/C40S showed an attenuated phenotype in mice, the molecular mechanisms behind this attenuation were further investigated. The results show that two mechanisms are responsible for the attenuation; (1) loss of the IFN antagonistic propriety characteristic of the wtRVFV NSs and (2) the inability of the attenuated mutant to degrade Proteine Kinase R (PKR). Copyright © 2018. Published by Elsevier B.V.

Mechanisms of fever production and lysis: lessons from experimental LPS fever.

Science.gov (United States)

Roth, Joachim; Blatteis, Clark M

2014-10-01

Fever is a cardinal symptom of infectious or inflammatory insults, but it can also arise from noninfectious causes. The fever-inducing agent that has been used most frequently in experimental studies designed to characterize the physiological, immunological and neuroendocrine processes and to identify the neuronal circuits that underlie the manifestation of the febrile response is lipopolysaccharide (LPS). Our knowledge of the mechanisms of fever production and lysis is largely based on this model. Fever is usually initiated in the periphery of the challenged host by the immediate activation of the innate immune system by LPS, specifically of the complement (C) cascade and Toll-like receptors. The first results in the immediate generation of the C component C5a and the subsequent rapid production of prostaglandin E2 (PGE2). The second, occurring after some delay, induces the further production of PGE2 by induction of its synthesizing enzymes and transcription and translation of proinflammatory cytokines. The Kupffer cells (Kc) of the liver seem to be essential for these initial processes. The subsequent transfer of the pyrogenic message from the periphery to the brain is achieved by neuronal and humoral mechanisms. These pathways subserve the genesis of early (neuronal signals) and late (humoral signals) phases of the characteristically biphasic febrile response to LPS. During the course of fever, counterinflammatory factors, "endogenous antipyretics," are elaborated peripherally and centrally to limit fever in strength and duration. The multiple interacting pro- and antipyretic signals and their mechanistic effects that underlie endotoxic fever are the subjects of this review.

Potential for a significant deep basin geothermal system in Tintic Valley, Utah

Science.gov (United States)

Hardwick, C.; Kirby, S.

2014-12-01

The combination of regionally high heat flow, deep basins, and permeable reservoir rocks in the eastern Great Basin may yield substantial new geothermal resources. We explore a deep sedimentary basin geothermal prospect beneath Tintic Valley in central Utah using new 2D and 3D models coupled with existing estimates of heat flow, geothermometry, and shallow hydrologic data. Tintic Valley is a sediment-filled basin bounded to the east and west by bedrock mountain ranges where heat-flow values vary from 85 to over 240 mW/m2. Based on modeling of new and existing gravity data, a prominent 30 mGal low indicates basin fill thickness may exceed 2 km. The insulating effect of relatively low thermal conductivity basin fill in Tintic Valley, combined with typical Great Basin heat flow, predict temperatures greater than 150 °C at 3 km depth. The potential reservoir beneath the basin fill is comprised of Paleozoic carbonate and clastic rocks. The hydrology of the Tintic Valley is characterized by a shallow, cool groundwater system that recharges along the upper reaches of the basin and discharges along the valley axis and to a series of wells. The east mountain block is warm and dry, with groundwater levels just above the basin floor and temperatures >50 °C at depth. The west mountain block contains a shallow, cool meteoric groundwater system. Fluid temperatures over 50 °C are sufficient for direct-use applications, such as greenhouses and aquaculture, while temperatures exceeding 140°C are suitable for binary geothermal power plants. The geologic setting and regionally high heat flow in Tintic Valley suggest a geothermal resource capable of supporting direct-use geothermal applications and binary power production could be present.

Discriminating fever behavior in house flies.

Directory of Open Access Journals (Sweden)

Robert D Anderson

Full Text Available Fever has generally been shown to benefit infected hosts. However, fever temperatures also carry costs. While endotherms are able to limit fever costs physiologically, the means by which behavioral thermoregulators constrain these costs are less understood. Here we investigated the behavioral fever response of house flies (Musca domestica L. challenged with different doses of the fungal entomopathogen, Beauveria bassiana. Infected flies invoked a behavioral fever selecting the hottest temperature early in the day and then moving to cooler temperatures as the day progressed. In addition, flies infected with a higher dose of fungus exhibited more intense fever responses. These variable patterns of fever are consistent with the observation that higher fever temperatures had greater impact on fungal growth. The results demonstrate the capacity of insects to modulate the degree and duration of the fever response depending on the severity of the pathogen challenge and in so doing, balance the costs and benefits of fever.

Interpretation of shallow crustal structure of the Imperial Valley, California, from seismic reflection profiles

Energy Technology Data Exchange (ETDEWEB)

Severson, L.K.

1987-05-01

Eight seismic reflection profiles (285 km total length) from the Imperial Valley, California, were provided to CALCRUST for reprocessing and interpretation. Two profiles were located along the western margin of the valley, five profiles were situated along the eastern margin and one traversed the deepest portion of the basin. These data reveal that the central basin contains a wedge of highly faulted sediments that thins to the east. Most of the faulting is strike-slip but there is evidence for block rotations on the scale of 5 to 10 kilometers within the Brawley Seismic Zone. These lines provide insight into the nature of the east and west edges of the Imperial Valley. The basement at the northwestern margin of the valley, to the north of the Superstition Hills, has been normal-faulted and blocks of basement material have ''calved'' into the trough. A blanket of sediments has been deposited on this margin. To the south of the Superstition Hills and Superstition Mountain, the top of the basement is a detachment surface that dips gently into the basin. This margin is also covered by a thick sequence sediments. The basement of the eastern margin consists of metamorphic rocks of the upper plate of the Chocolate Mountain Thrust system underlain by the Orocopia Schist. These rocks dip to the southeast and extend westward to the Sand Hills Fault but do not appear to cross it. Thus, the Sand Hills Fault is interpreted to be the southern extension of the San Andreas Fault. North of the Sand Hills Fault the East Highline Canal seismicity lineament is associated with a strike-slip fault and is probably linked to the Sand Hills Fault. Six geothermal areas crossed by these lines, in agreement with previous studies of geothermal reservoirs, are associated with ''faded'' zones, Bouguer gravity and heat flow maxima, and with higher seismic velocities than surrounding terranes.

Climate change and the emergence of vector-borne diseases in Europe: case study of dengue fever.

Science.gov (United States)

Bouzid, Maha; Colón-González, Felipe J; Lung, Tobias; Lake, Iain R; Hunter, Paul R

2014-08-22

Dengue fever is the most prevalent mosquito-borne viral disease worldwide. Dengue transmission is critically dependent on climatic factors and there is much concern as to whether climate change would spread the disease to areas currently unaffected. The occurrence of autochthonous infections in Croatia and France in 2010 has raised concerns about a potential re-emergence of dengue in Europe. The objective of this study is to estimate dengue risk in Europe under climate change scenarios. We used a Generalized Additive Model (GAM) to estimate dengue fever risk as a function of climatic variables (maximum temperature, minimum temperature, precipitation, humidity) and socioeconomic factors (population density, urbanisation, GDP per capita and population size), under contemporary conditions (1985-2007) in Mexico. We then used our model estimates to project dengue incidence under baseline conditions (1961-1990) and three climate change scenarios: short-term 2011-2040, medium-term 2041-2070 and long-term 2071-2100 across Europe. The model was used to calculate average number of yearly dengue cases at a spatial resolution of 10 × 10 km grid covering all land surface of the currently 27 EU member states. To our knowledge, this is the first attempt to model dengue fever risk in Europe in terms of disease occurrence rather than mosquito presence. The results were presented using Geographical Information System (GIS) and allowed identification of areas at high risk. Dengue fever hot spots were clustered around the coastal areas of the Mediterranean and Adriatic seas and the Po Valley in northern Italy. This risk assessment study is likely to be a valuable tool assisting effective and targeted adaptation responses to reduce the likely increased burden of dengue fever in a warmer world.

[Familial Mediterranean fever - clinical picture, diagnosis and treatment].

Science.gov (United States)

Dallos, Tomáš; Ilenčíková, Denisa; Kovács, László

2014-01-01

Familial mediterranean fever (FMF) is the most prevalent genetically determined autoinflammatory disease. FMF significantly decreases the quality of life and limits life expectancy due to the development of amyloidosis in affected individuals. Prevalence of FMF is highest in the south-eastern Mediterraneans. In other parts of the world, its occurance is often restricted to high-risk ethnic goups. In Central Europe, experience with FMF is scarse. As for Slovakia, we have reported the first cases of FMF in ethnic Slovaks only recently. Along with their complicated fates, this has lead us to compile a comprehensive overview of the clinical picture, diagnosis and treatment of this elusive disease. Hereby we hope to be able to promote the awareness about this disease and possibly aid the diagnosis in new patients.

Rift Valley fever virus-infected mosquito ova and associated pathology: possible implications for endemic maintenance

Directory of Open Access Journals (Sweden)

Romoser WS

2011-09-01

Full Text Available William S Romoser1, Marco Neira Oviedo1, Kriangkrai Lerdthusnee2, Lisa A Patrican3, Michael J Turell4, David J Dohm4, Kenneth J Linthicum5, Charles L Bailey61Department of Biomedical Sciences, College of Osteopathic Medicine, Tropical Disease Institute, Ohio University, Athens, Ohio, USA; 2Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand; 3Infectious Disease Division, National Center for Medical Intelligence, Fort Detrick, Frederick, Maryland, USA; 4Department of Vector Assessment, Virology Division, United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, USA; 5Center for Medical, Agricultural, and Veterinary Entomology, United States Department of Agriculture – Agricultural Research Service, Gainesville, Florida, USA; 6National Center for Biodefense and Infectious Disease, School of Systems Biology, College of Science, George Mason University, Manassas, Virginia, USABackground: Endemic/enzootic maintenance mechanisms like vertical transmission (pathogen passage from infected adults to their offspring are central in the epidemiology of zoonotic pathogens. In Kenya, Rift Valley fever virus (RVFV may be maintained by vertical transmission in ground-pool mosquitoes such as Aedes mcintoshi. RVFV can cause serious morbidity and mortality in humans and livestock. Past epidemics/epizootics have occurred in sub-Saharan Africa but, since the late 1970s, RVFV has also appeared in North Africa and the Middle East. Preliminary results revealed RVFV-infected eggs in Ae. mcintoshi after virus injection into the hemocoel after the first of two blood meals, justifying further study.Methods: Mosquitoes were collected from an artificially flooded water-catching depression along a stream in Kenya, shipped live to the USA, and studied using an immunocytochemical method for RVFV-antigen localization in mosquito sections.Results and conclusion: After virus injection into the

Oropouche Fever: A Review.

Science.gov (United States)

Sakkas, Hercules; Bozidis, Petros; Franks, Ashley; Papadopoulou, Chrissanthy

2018-04-04

Oropouche fever is an emerging zoonotic disease caused by Oropouche virus (OROV), an arthropod transmitted Orthobunyavirus circulating in South and Central America. During the last 60 years, more than 30 epidemics and over half a million clinical cases attributed to OROV infection have been reported in Brazil, Peru, Panama, Trinidad and Tobago. OROV fever is considered the second most frequent arboviral febrile disease in Brazil after dengue fever. OROV is transmitted through both urban and sylvatic transmission cycles, with the primary vector in the urban cycle being the anthropophilic biting midge Culicoides paraensis . Currently, there is no evidence of direct human-to-human OROV transmission. OROV fever is usually either undiagnosed due to its mild, self-limited manifestations or misdiagnosed because its clinical characteristics are similar to dengue, chikungunya, Zika and yellow fever, including malaria as well. At present, there is no specific antiviral treatment, and in the absence of a vaccine for effective prophylaxis of human populations in endemic areas, the disease prevention relies solely on vector control strategies and personal protection measures. OROV fever is considered to have the potential to spread across the American continent and under favorable climatic conditions may expand its geographic distribution to other continents. In view of OROV's emergence, increased interest for formerly neglected tropical diseases and within the One Health concept, the existing knowledge and gaps of knowledge on OROV fever are reviewed.

Travelers' Health: Typhoid and Paratyphoid Fever

Science.gov (United States)

... days should raise suspicion of typhoid or paratyphoid fever. Typhoid fever is a nationally notifiable disease. TREATMENT Specific ... typhoid-fever Table 3-21. Vaccines to prevent typhoid fever VACCINA- TION AGE (y) DOSE, MODE OF ADMINISTRA- ...

NNDSS - Table II. Salmonellosis (excluding typhoid fever and paratyphoid fever) to Shigellosis

Data.gov (United States)

U.S. Department of Health & Human Services — NNDSS - Table II. Salmonellosis (excluding typhoid fever and paratyphoid fever) to Shigellosis - 2018. In this Table, provisional cases of selected notifiable...

Using reverse genetics to manipulate the NSs gene of the Rift Valley fever virus MP-12 strain to improve vaccine safety and efficacy.

Science.gov (United States)

Kalveram, Birte; Lihoradova, Olga; Indran, Sabarish V; Ikegami, Tetsuro

2011-11-01

Rift Valley fever virus (RVFV), which causes hemorrhagic fever, neurological disorders or blindness in humans, and a high rate abortion and fetal malformation in ruminants, has been classified as a HHS/USDA overlap select agent and a risk group 3 pathogen. It belongs to the genus Phlebovirus in the family Bunyaviridae and is one of the most virulent members of this family. Several reverse genetics systems for the RVFV MP-12 vaccine strain as well as wild-type RVFV strains, including ZH548 and ZH501, have been developed since 2006. The MP-12 strain (which is a risk group 2 pathogen and a non-select agent) is highly attenuated by several mutations in its M- and L-segments, but still carries virulent S-segment RNA, which encodes a functional virulence factor, NSs. The rMP12-C13type (C13type) carrying 69% in-frame deletion of NSs ORF lacks all the known NSs functions, while it replicates as efficient as does MP-12 in VeroE6 cells lacking type-I IFN. NSs induces a shut-off of host transcription including interferon (IFN)-beta mRNA and promotes degradation of double-stranded RNA-dependent protein kinase (PKR) at the post-translational level. IFN-beta is transcriptionally upregulated by interferon regulatory factor 3 (IRF-3), NF-kB and activator protein-1 (AP-1), and the binding of IFN-beta to IFN-alpha/beta receptor (IFNAR) stimulates the transcription of IFN-alpha genes or other interferon stimulated genes (ISGs), which induces host antiviral activities, whereas host transcription suppression including IFN-beta gene by NSs prevents the gene upregulations of those ISGs in response to viral replication although IRF-3, NF-kB and activator protein-1 (AP-1) can be activated by RVFV7. Thus, NSs is an excellent target to further attenuate MP-12, and to enhance host innate immune responses by abolishing the IFN-beta suppression function. Here, we describe a protocol for generating a recombinant MP-12 encoding mutated NSs, and provide an example of a screening method to identify

Re-emergence of Rift Valley fever virus in Barkedji (Senegal, West Africa) in 2002-2003: identification of new vectors and epidemiological implications.

Science.gov (United States)

Ba, Y; Sall, A A; Diallo, D; Mondo, M; Girault, L; Dia, I; Diallo, M

2012-09-01

The Rift Valley fever virus (RVFV) is a threat that must not be neglected, as the consequences of RVFV are dramatic, both for human and animal health. This virus is a zoonotic virus that already has demonstrated a real capacity for re-emerging after long periods of silence, as observed in Barkedji (Senegal, West Africa) in 2002. In this article we present the 2nd emergence in Barkedji after the 1st manifestation in 1993, and for the 1st time the circulation of RVFV during 2 consecutive years among mosquito populations in Senegal. As part of the entomological surveillance program undertaken since 1990 to detect circulation of the RVFV in Barkedji, 108,336 mosquitoes belonging to 34 species and 5 genera were collected in 2002-2003. Aedes vexans and Culex poicilipes, previously known to be vectors of RVFV in Senegal, comprised 88.7% of the total collection. In 2002, Ae. vexans was the most abundant mosquito, followed by Cx. poicilipes; the opposite situation was observed in 2003. In 2002, 29 and 10 RVFV isolates were obtained from Cx. poicilipes (minimum infection rate [MIR] = 0.13%) and Ae. vexans (MIR = 0.02%) pools, respectively and the MIR for the 2 species were significantly different (chi2 = 34.65; df = 1, P < 0.001). In 2003, 7 RVFV strains were isolated from Cx. poicilipes (3, MIR = 0.03), Mansonia africana (2, MIR = 0.08), Ae. fowleri (1), and Ma. uniformis (1, MIR = 0.05). The 3 latter species were found to be associated with RVFV for the 1st time in Senegal. A significant decrease in MIR was observed from 2002 to 2003 (chi2 6.28; df = 1, P = 0.01) for Cx. poicilipes, the only species involved in the transmission during the 2 sampling years.

Rift Valley Fever Vaccine Virus Clone 13 Is Able to Cross the Ovine Placental Barrier Associated with Foetal Infections, Malformations, and Stillbirths.

Directory of Open Access Journals (Sweden)

Birgit Makoschey

2016-03-01

Full Text Available Rift Valley fever virus (RVFV is a mosquito-borne pathogen that affects domesticated ruminants and occasionally humans. Classical RVF vaccines are based on formalin-inactivated virus or the live-attenuated Smithburn strain. The inactivated vaccine is highly safe but requires multiple administrations and yearly re-vaccinations. Although the Smithburn vaccine provides solid protection after a single vaccination, this vaccine is not safe for pregnant animals. An alternative live-attenuated vaccine, named Clone 13, carries a large natural deletion in the NSs gene which encodes the major virulence factor of the virus. The Clone 13 vaccine was previously shown to be safe for young lambs and calves. Moreover, a study in pregnant ewes suggested that the vaccine could also be applied safely during gestation. To anticipate on a possible future incursion of RVFV in Europe, we have evaluated the safety of Clone 13 for young lambs and pregnant ewes. In line with the guidelines from the World Organisation for Animal health (Office International des Epizooties, OIE and regulations of the European Pharmacopeia (EP, these studies were performed with an overdose. Our studies with lambs showed that Clone 13 dissemination within vaccinated animals is very limited. Moreover, the Clone 13 vaccine virus was not shed nor spread to in-contact sentinels and did not revert to virulence upon animal-to-animal passage. Importantly, a large experiment with pregnant ewes demonstrated that the Clone 13 virus is able to spread to the fetus, resulting in malformations and stillbirths. Altogether, our results suggest that Clone 13 can be applied safely in lambs, but that caution should be taken when Clone 13 is used in pregnant animals, particularly during the first trimester of gestation.

Rift Valley Fever Vaccine Virus Clone 13 Is Able to Cross the Ovine Placental Barrier Associated with Foetal Infections, Malformations, and Stillbirths

Science.gov (United States)

Makoschey, Birgit; van Kilsdonk, Emma; Hubers, Willem R.; Vrijenhoek, Mieke P.; Smit, Marianne; Wichgers Schreur, Paul J.; Kortekaas, Jeroen; Moulin, Véronique

2016-01-01

Rift Valley fever virus (RVFV) is a mosquito-borne pathogen that affects domesticated ruminants and occasionally humans. Classical RVF vaccines are based on formalin-inactivated virus or the live-attenuated Smithburn strain. The inactivated vaccine is highly safe but requires multiple administrations and yearly re-vaccinations. Although the Smithburn vaccine provides solid protection after a single vaccination, this vaccine is not safe for pregnant animals. An alternative live-attenuated vaccine, named Clone 13, carries a large natural deletion in the NSs gene which encodes the major virulence factor of the virus. The Clone 13 vaccine was previously shown to be safe for young lambs and calves. Moreover, a study in pregnant ewes suggested that the vaccine could also be applied safely during gestation. To anticipate on a possible future incursion of RVFV in Europe, we have evaluated the safety of Clone 13 for young lambs and pregnant ewes. In line with the guidelines from the World Organisation for Animal health (Office International des Epizooties, OIE) and regulations of the European Pharmacopeia (EP), these studies were performed with an overdose. Our studies with lambs showed that Clone 13 dissemination within vaccinated animals is very limited. Moreover, the Clone 13 vaccine virus was not shed nor spread to in-contact sentinels and did not revert to virulence upon animal-to-animal passage. Importantly, a large experiment with pregnant ewes demonstrated that the Clone 13 virus is able to spread to the fetus, resulting in malformations and stillbirths. Altogether, our results suggest that Clone 13 can be applied safely in lambs, but that caution should be taken when Clone 13 is used in pregnant animals, particularly during the first trimester of gestation. PMID:27031621

Rat bite fever.

NARCIS (Netherlands)

Gaastra, W.; Boot, R.G.A.; Ho, H.; Lipman, L.J.A.

2009-01-01

Rat bite fever (RBF) is a bacterial zoonosis for which two causal bacterial species have been identified: Streptobacillis moniliformis and Spirillum minus. Haverhill fever (HF) is a form of S. moniliformis infection believed to develop after ingestion of contaminated food or water. Here the

Oropouche Fever: A Review

Directory of Open Access Journals (Sweden)

Hercules Sakkas

2018-04-01

Full Text Available Oropouche fever is an emerging zoonotic disease caused by Oropouche virus (OROV, an arthropod transmitted Orthobunyavirus circulating in South and Central America. During the last 60 years, more than 30 epidemics and over half a million clinical cases attributed to OROV infection have been reported in Brazil, Peru, Panama, Trinidad and Tobago. OROV fever is considered the second most frequent arboviral febrile disease in Brazil after dengue fever. OROV is transmitted through both urban and sylvatic transmission cycles, with the primary vector in the urban cycle being the anthropophilic biting midge Culicoides paraensis. Currently, there is no evidence of direct human-to-human OROV transmission. OROV fever is usually either undiagnosed due to its mild, self-limited manifestations or misdiagnosed because its clinical characteristics are similar to dengue, chikungunya, Zika and yellow fever, including malaria as well. At present, there is no specific antiviral treatment, and in the absence of a vaccine for effective prophylaxis of human populations in endemic areas, the disease prevention relies solely on vector control strategies and personal protection measures. OROV fever is considered to have the potential to spread across the American continent and under favorable climatic conditions may expand its geographic distribution to other continents. In view of OROV’s emergence, increased interest for formerly neglected tropical diseases and within the One Health concept, the existing knowledge and gaps of knowledge on OROV fever are reviewed.

Characterization and pathogenesis of aerosolized eastern equine encephalitis in the common marmoset (Callithrix jacchus)

OpenAIRE

Porter, Aimee I.; Erwin-Cohen, Rebecca A.; Twenhafel, Nancy; Chance, Taylor; Yee, Steven B.; Kern, Steven J.; Norwood, David; Hartman, Laurie J.; Parker, Michael D.; Glass, Pamela J.; DaSilva, Luis

2017-01-01

Background Licensed antiviral therapeutics and vaccines to protect against eastern equine encephalitis virus (EEEV) in humans currently do not exist. Animal models that faithfully recapitulate the clinical characteristics of human EEEV encephalitic disease, including fever, drowsiness, anorexia, and neurological signs such as seizures, are needed to satisfy requirements of the Food and Drug Administration (FDA) for clinical product licensing under the Animal Rule. Methods In an effort to meet...

77 FR 33237 - Saline Valley Warm Springs Management Plan/Environmental Impact Statement, Death Valley National...

Science.gov (United States)

2012-06-05

... Valley Warm Springs Management Plan/Environmental Impact Statement, Death Valley National Park, Inyo... an Environmental Impact Statement for the Saline Valley Warm Springs Management Plan, Death Valley... analysis process for the Saline Valley Warm Springs Management Plan for Death Valley [[Page 33238...

Crimean–Congo Hemorrhagic Fever Virus and Borrelia burgdorferi sensu lato in Ticks from Kosovo and Albania

OpenAIRE

Kurtesh Sherifi; Agim Rexhepi; Kristaq Berxholi; Blerta Mehmedi; Rreze M. Gecaj; Zamira Hoxha; Anja Joachim; Georg G. Duscher

2018-01-01

Tick-borne diseases pose a serious threat to human health in South-Eastern Europe, including Kosovo. While Crimean–Congo hemorrhagic fever (CCHF) is a well-known emerging infection in this area, there are no accurate data on Lyme borreliosis and tick-borne encephalitis (TBE). Therefore, we sampled and tested 795 ticks. Ixodes ricinus (n = 218), Dermacentor marginatus (n = 98), and Haemaphysalis spp. (n = 24) were collected from the environment by flagging (all from Kosovo), while Hyalomma mar...

[Familial Mediterranean fever - first experiences in Slovakia].

Science.gov (United States)

Dallos, Tomáš; Gálová, Lucia Lukáčiková; Macejková, Eva; Sedlačko, Jozef; Toplak, Nataša; Debeljak, Maruša; Sargsyan, Hasmik; Ilenčíková, Denisa; Kovács, László

2014-01-01

Familial Mediterranean fever (FMF) is the most prevalent genetically determined autoinflammatory disease. FMF significantly decreases the quality of life and limits life expectancy due to the development of amyloidosis in affected individuals. Prevalence of FMF is highest in the south-eastern Mediterraneans. In other parts of the world, its occurance is often restricted to high-risk ethnic groups. In Central Europe, experience with FMF is scarse to none, as in the case of Slovakia, where no cases have been reported, so far. Herein we report the first five patients (3 adults and 2 children, 4 native Slovaks) in whom the diagnosis of FMF could be confirmed in Slovakia. Our experience demonstrates that FMF does occur in low-risk populations in Central Europe. Due to low prevalence and lack of experience, FMF diagnosis may be significantly delayed (4.5-30 years) and undiagnosed cases are to be expected in our population.

Yellow Fever Vaccine: What You Need to Know

Science.gov (United States)

... How can I prevent yellow fever? Yellow fever vaccine Yellow fever vaccine can prevent yellow fever. Yellow fever vaccine ... such as those containing DEET. 3 Yellow fever vaccine Yellow fever vaccine is a live, weakened virus. It is ...

Valley Fever (Coccidioidomycosis)

Science.gov (United States)

... Testing Treatment & Outcomes Health Professionals Statistics More Resources Candidiasis Candida infections of the mouth, throat, and esophagus Vaginal candidiasis Invasive candidiasis Definition Symptoms Risk & Prevention Sources Diagnosis ...

Psychosis in dengue fever

OpenAIRE

Suprakash Chaudhury; Biswajit Jagtap; Deepak Kumar Ghosh

2017-01-01

An 18-year-old male student developed abnormal behavior while undergoing treatment for dengue fever. He was ill-kempt, irritable and had auditory and visual hallucinations and vague persecutory delusions in clear sensorium with impaired insight. The psychotic episode had a temporal correlation with dengue fever. Psychiatric comorbidities of dengue fever including mania, anxiety, depression, and catatonia are mentioned in literature but the literature on the psychosis following dengue is spars...

Persisting and strong warming hiatus over eastern China during the past two decades

Science.gov (United States)

Chen, Yang; Zhai, Panmao

2017-10-01

During the past two decades since 1997, eastern China has experienced a warming hiatus punctuated by significant cooling in daily-minimum temperature (Tmin), particularly during early-mid winter. By arbitrarily configuring start and end years, a ‘vantage hiatus period’ in eastern China is detected over 1998-2013, during when the domain-averaged Tmin exhibited the strongest cooling trend and the number of significant cooling stations peaked. Regions most susceptible to the warming hiatus are located in North China, the Yangtze-Huai River Valley and South China, where significant cooling in Tmin persisted through 2016. This sustained hiatus gave rise to increasingly frequent and severe cold extremes there. Concerning its prolonged persistency and great cooling rate, the recent warming hiatus over eastern China deviates much from most historical short-term trends during the past five decades, and thus could be viewed as an outlier against the prevalent warming context.

Effect of (social) media on the political figure fever model: Jokowi-fever model

Science.gov (United States)

Yong, Benny; Samat, Nor Azah

2016-02-01

In recent years, political figures begin to utilize social media as one of alternative to engage in communication with their supporters. Publics referred to Jokowi, one of the candidates in Indonesia presidential election in 2014, as the first politician in Indonesia to truly understand the power of social media. Social media is very important in shaping public opinion. In this paper, effect of social media on the Jokowi-fever model in a closed population will be discussed. Supporter population is divided into three class sub-population, i.e susceptible supporters, Jokowi infected supporters, and recovered supporters. For case no positive media, there are two equilibrium points; the Jokowi-fever free equilibrium point in which it locally stable if basic reproductive ratio less than one and the Jokowi-fever endemic equilibrium point in which it locally stable if basic reproductive ratio greater than one. For case no negative media, there is only the Jokowi-fever endemic equilibrium point in which it locally stable if the condition is satisfied. Generally, for case positive media proportion is positive, there is no Jokowi-fever free equilibrium point. The numerical result shows that social media gives significantly effect on Jokowi-fever model, a sharp increase or a sharp decrease in the number of Jokowi infected supporters. It is also shown that the boredom rate is one of the sensitive parameters in the Jokowi-fever model; it affects the number of Jokowi infected supporters.

STUDIES ON TUBERCULIN FEVER

Science.gov (United States)

Hall, Charles H.; Atkins, Elisha

1959-01-01

Evidence has been presented that the fever elicited by intravenous administration of old tuberculin (O.T.) in BCG-infected rabbits is a specific property of this hypersensitivity system and is probably not due to contamination of tuberculin with bacterial endotoxins. Daily injections of O.T. in sensitized animals resulted in a rapid tolerance to its pyrogenic effect. Tuberculin tolerance can be differentiated from that occurring with endotoxins and was invariably associated with the development of a negative skin test. The mechanism of this tolerance would thus appear to be desensitization. A circulating pyrogen found during tuberculin fever was indistinguishable in its biologic effects from endogenous pyrogens obtained in several other types of experimental fever. This material produced fevers in normal recipients and therefore may be clearly differentiated from O.T. itself which was pyrogenic only to sensitized animals. Since the titer of serum pyrogen was directly proportional to the degree of fever induced by injection of O.T. in the donor animals, a causal relation is suggested. On the basis of these findings, it is postulated that tuberculin fever is due to a circulating endogenous pyrogen released by a specific action of O.T. on sensitized cells of the host. PMID:13641561

Yellow fever: an update.

Science.gov (United States)

Monath, T P

2001-08-01

Yellow fever, the original viral haemorrhagic fever, was one of the most feared lethal diseases before the development of an effective vaccine. Today the disease still affects as many as 200,000 persons annually in tropical regions of Africa and South America, and poses a significant hazard to unvaccinated travellers to these areas. Yellow fever is transmitted in a cycle involving monkeys and mosquitoes, but human beings can also serve as the viraemic host for mosquito infection. Recent increases in the density and distribution of the urban mosquito vector, Aedes aegypti, as well as the rise in air travel increase the risk of introduction and spread of yellow fever to North and Central America, the Caribbean and Asia. Here I review the clinical features of the disease, its pathogenesis and pathophysiology. The disease mechanisms are poorly understood and have not been the subject of modern clinical research. Since there is no specific treatment, and management of patients with the disease is extremely problematic, the emphasis is on preventative vaccination. As a zoonosis, yellow fever cannot be eradicated, but reduction of the human disease burden is achievable through routine childhood vaccination in endemic countries, with a low cost for the benefits obtained. The biological characteristics, safety, and efficacy of live attenuated, yellow fever 17D vaccine are reviewed. New applications of yellow fever 17D virus as a vector for foreign genes hold considerable promise as a means of developing new vaccines against other viruses, and possibly against cancers.

Typhoid fever

DEFF Research Database (Denmark)

Wain, John; Hendriksen, Rene S.; Mikoleit, Matthew L.

2015-01-01

Control of typhoid fever relies on clinical information, diagnosis, and an understanding for the epidemiology of the disease. Despite the breadth of work done so far, much is not known about the biology of this human-adapted bacterial pathogen and the complexity of the disease in endemic areas...... with shifting trends in enteric fever. This knowledge is crucial, both to control the disease and to manage cases. Additionally, salmonella serovars that cause human infection can change over time and location. In areas of Asia, multidrug-resistant Salmonella enterica serovar Typhi (S Typhi) has been the main...... cause of enteric fever, but now S Typhi is being displaced by infections with drug-resistant S enterica serovar Paratyphi A. New conjugate vaccines are imminent and new treatments have been promised, but the engagement of local medical and public health institutions in endemic areas is needed to allow...

Oropouche Fever: A Review

OpenAIRE

Hercules Sakkas; Petros Bozidis; Ashley Franks; Chrissanthy Papadopoulou

2018-01-01

Oropouche fever is an emerging zoonotic disease caused by Oropouche virus (OROV), an arthropod transmitted Orthobunyavirus circulating in South and Central America. During the last 60 years, more than 30 epidemics and over half a million clinical cases attributed to OROV infection have been reported in Brazil, Peru, Panama, Trinidad and Tobago. OROV fever is considered the second most frequent arboviral febrile disease in Brazil after dengue fever. OROV is transmitted through both urban and s...

Plant diversity and conservation status of Himalayan Region Poonch Valley Azad Kashmir (Pakistan).

Science.gov (United States)

Khan, Muhammad Azam; Khan, Mir Ajab; Hussain, Mazhar; Mujtaba, Ghulam

2014-09-01

The plant diversity of Himalayan region has been reduced to greater extent due to environmental degradation and human exploitation. Anthropogenic disturbance was the major factor responsible for fragmentation of forest vegetation into small patches. Little research has been conducted in the Himalayan region of Poonch Valley of North eastern Pakistan with reference to plants biodiversity and its conservation. The present research was carried out to provide a checklist of vegetation for biodiversity conservation. A total of 430 vascular and 5 nonvascular plant species with 5 species of Bryophytes (5 families), 13 species of Pteridophytes (6 families), 4 species of Gymnosperms (1 family) and 413 species of angiosperms (95 families) were enumerated from the Poonch valley Azad Kashmir. The genera were classified into three categories according to the number of species. 25 plant communities with phytosociological parameters and diversity indices were reported. Present study revealed that there were 145 threatened, 30 endangered, 68 vulnerable and 47 rare species. It is recorded that extensive grazing, uprooting of plants and soil slope erosion intensify the environmental problems. Since there is maximum exploitation of vegetation, the valley showed a decline in plant diversity. The study was also indicated that the main threats to the biodiversity are expansion of settlement and army installations in the forest area of the valley. For sustainable use In-situ and Ex-situ conservation, controlled harvesting and afforestation may be the solution. Moreover, forest area should be declared prohibited for settlements and army installations.

HCMM: Soil moisture in relation to geologic structure and lithology, northern California. [Sacremento Valley

Science.gov (United States)

Rich, E. I. (Principal Investigator)

1979-01-01

The author has identified the following significant results. A preliminary analysis of the HCMM imagery of the project area indicated that locally some differentiation of lithologic units within the Northern Coast Range may be possible. Of significance, however, was a thermally cool linear area that appeared on the 30 May 1978 Nite-IR. This linear feature seemed to coincide with the Bear Mt. Fault and with the axis of the Chico Monocline along the eastern margin of the Sacramento Valley.

Preliminary mapping of surficial geology of Midway Valley Yucca Mountain Project, Nye County, Nevada

International Nuclear Information System (INIS)

Wesling, J.R.; Bullard, T.F.; Swan, F.H.; Perman, R.C.; Angell, M.M.; Gibson, J.D.

1992-04-01

The tectonics program for the proposed high-level nuclear waste repository at Yucca Mountain in southwestern Nevada must evaluate the potential for surface faulting beneath the prospective surface facilities. To help meet this goal, Quaternary surficial mapping studies and photolineament analyses were conducted to provide data for evaluating the location, recency, and style of faulting with Midway Valley at the eastern base of Yucca Mountain, the preferred location of these surface facilities. This interim report presents the preliminary results of this work

Development and preliminary evaluation of a multiplexed amplification and next generation sequencing method for viral hemorrhagic fever diagnostics.

Directory of Open Access Journals (Sweden)

Annika Brinkmann

2017-11-01

Full Text Available We describe the development and evaluation of a novel method for targeted amplification and Next Generation Sequencing (NGS-based identification of viral hemorrhagic fever (VHF agents and assess the feasibility of this approach in diagnostics.An ultrahigh-multiplex panel was designed with primers to amplify all known variants of VHF-associated viruses and relevant controls. The performance of the panel was evaluated via serially quantified nucleic acids from Yellow fever virus, Rift Valley fever virus, Crimean-Congo hemorrhagic fever (CCHF virus, Ebola virus, Junin virus and Chikungunya virus in a semiconductor-based sequencing platform. A comparison of direct NGS and targeted amplification-NGS was performed. The panel was further tested via a real-time nanopore sequencing-based platform, using clinical specimens from CCHF patients.The multiplex primer panel comprises two pools of 285 and 256 primer pairs for the identification of 46 virus species causing hemorrhagic fevers, encompassing 6,130 genetic variants of the strains involved. In silico validation revealed that the panel detected over 97% of all known genetic variants of the targeted virus species. High levels of specificity and sensitivity were observed for the tested virus strains. Targeted amplification ensured viral read detection in specimens with the lowest virus concentration (1-10 genome equivalents and enabled significant increases in specific reads over background for all viruses investigated. In clinical specimens, the panel enabled detection of the causative agent and its characterization within 10 minutes of sequencing, with sample-to-result time of less than 3.5 hours.Virus enrichment via targeted amplification followed by NGS is an applicable strategy for the diagnosis of VHFs which can be adapted for high-throughput or nanopore sequencing platforms and employed for surveillance or outbreak monitoring.

Development and preliminary evaluation of a multiplexed amplification and next generation sequencing method for viral hemorrhagic fever diagnostics.

Science.gov (United States)

Brinkmann, Annika; Ergünay, Koray; Radonić, Aleksandar; Kocak Tufan, Zeliha; Domingo, Cristina; Nitsche, Andreas

2017-11-01

We describe the development and evaluation of a novel method for targeted amplification and Next Generation Sequencing (NGS)-based identification of viral hemorrhagic fever (VHF) agents and assess the feasibility of this approach in diagnostics. An ultrahigh-multiplex panel was designed with primers to amplify all known variants of VHF-associated viruses and relevant controls. The performance of the panel was evaluated via serially quantified nucleic acids from Yellow fever virus, Rift Valley fever virus, Crimean-Congo hemorrhagic fever (CCHF) virus, Ebola virus, Junin virus and Chikungunya virus in a semiconductor-based sequencing platform. A comparison of direct NGS and targeted amplification-NGS was performed. The panel was further tested via a real-time nanopore sequencing-based platform, using clinical specimens from CCHF patients. The multiplex primer panel comprises two pools of 285 and 256 primer pairs for the identification of 46 virus species causing hemorrhagic fevers, encompassing 6,130 genetic variants of the strains involved. In silico validation revealed that the panel detected over 97% of all known genetic variants of the targeted virus species. High levels of specificity and sensitivity were observed for the tested virus strains. Targeted amplification ensured viral read detection in specimens with the lowest virus concentration (1-10 genome equivalents) and enabled significant increases in specific reads over background for all viruses investigated. In clinical specimens, the panel enabled detection of the causative agent and its characterization within 10 minutes of sequencing, with sample-to-result time of less than 3.5 hours. Virus enrichment via targeted amplification followed by NGS is an applicable strategy for the diagnosis of VHFs which can be adapted for high-throughput or nanopore sequencing platforms and employed for surveillance or outbreak monitoring.

Geochemistry of groundwater in the eastern Snake River Plain aquifer, Idaho National Laboratory and vicinity, eastern Idaho

Science.gov (United States)

Rattray, Gordon W.

2018-05-30

Nuclear research activities at the U.S. Department of Energy (DOE) Idaho National Laboratory (INL) in eastern Idaho produced radiochemical and chemical wastes that were discharged to the subsurface, resulting in detectable concentrations of some waste constituents in the eastern Snake River Plain (ESRP) aquifer. These waste constituents may pose risks to the water quality of the aquifer. In order to understand these risks to water quality the U.S. Geological Survey, in cooperation with the DOE, conducted a study of groundwater geochemistry to improve the understanding of hydrologic and chemical processes in the ESRP aquifer at and near the INL and to understand how these processes affect waste constituents in the aquifer.Geochemistry data were used to identify sources of recharge, mixing of water, and directions of groundwater flow in the ESRP aquifer at the INL. The geochemistry data were analyzed from 167 sample sites at and near the INL. The sites included 150 groundwater, 13 surface-water, and 4 geothermal-water sites. The data were collected between 1952 and 2012, although most data collected at the INL were collected from 1989 to 1996. Water samples were analyzed for all or most of the following: field parameters, dissolved gases, major ions, dissolved metals, isotope ratios, and environmental tracers.Sources of recharge identified at the INL were regional groundwater, groundwater from the Little Lost River (LLR) and Birch Creek (BC) valleys, groundwater from the Lost River Range, geothermal water, and surface water from the Big Lost River (BLR), LLR, and BC. Recharge from the BLR that may have occurred during the last glacial epoch, or paleorecharge, may be present at several wells in the southwestern part of the INL. Mixing of water at the INL primarily included mixing of surface water with groundwater from the tributary valleys and mixing of geothermal water with regional groundwater. Additionally, a zone of mixing between tributary valley water and

Geohydrology and Water Quality of the Valley-Fill Aquifer System in the Upper Sixmile Creek and West Branch Owego Creek Valleys in the Town of Caroline, Tompkins County, New York

Science.gov (United States)

Miller, Todd S.

2009-01-01

In 2002, the U.S. Geological Survey, in cooperation with the Town of Caroline and Tompkins County Planning Department, began a study of the valley-fill aquifer system in upper Sixmile Creek and headwaters of West Branch Owego Creek valleys in the Town of Caroline, NY. The purpose of the study is to provide geohydrologic data to county and town planners as they develop a strategy to manage and protect their water resources. The first aquifer reach investigated in this series is in the Town of Caroline and includes the upper Sixmile Creek valley and part of West Branch Owego Creek valley. The portions of the valley-fill aquifer system that are comprised of saturated coarse-grained sediments including medium to coarse sand and sandy gravel form the major aquifers. Confined sand and gravel units form the major aquifers in the western and central portions of the upper Sixmile Creek valley, and an unconfined sand and gravel unit forms the major aquifer in the eastern portion of the upper Sixmile Creek valley and in the headwaters of the West Branch Owego Creek valley. The valley-fill deposits are thinnest near the edges of the valley where they pinch out along the till-mantled bedrock valley walls. The thickness of the valley fill in the deepest part of the valley, at the western end of the study area, is about 100 feet (ft); the thickness is greater than 165 ft on top of the Valley Heads Moraine in the central part of the valley. An estimated 750 people live over and rely on groundwater from the valley-fill aquifers in upper Sixmile Creek and West Branch Owego Creek valleys. Most groundwater withdrawn from the valley-fill aquifers is pumped from wells with open-ended 6-inch diameter casings; the remaining withdrawals are from shallow dug wells or cisterns that collect groundwater that discharges to springs (especially in the Brooktondale area). The valley-fill aquifers are the sources of water for about 200 households, several apartment complexes, two mobile home parks

Lithotrites and postoperative fever

DEFF Research Database (Denmark)

Chu, David I; Lipkin, Michael E; Wang, Agnes J

2013-01-01

OBJECTIVE: To compare the risks of fever from different lithotrites after percutaneous nephrolithotomy (PNL). MATERIALS AND METHODS: The Clinical Research Office of the Endourological Society (CROES) PNL database is a prospective, multi-institutional, international PNL registry. Of 5,803 total...... with fever [Odds Ratio (OR) 1.17, p = 0.413], while diabetes (OR 1.32, p = 0.048), positive urine culture (OR 2.08, p PNL...... fever was not significantly different among the various lithotrites used in the CROES PNL study....

Familial Mediterranean Fever

Directory of Open Access Journals (Sweden)

Adem Kucuk

2014-01-01

Full Text Available Familial Mediterranean Fever is an autosomal recessive inherited disease with a course of autoinflammation, which is characterized by the episodes of fever and serositis. It affects the populations from Mediterranean basin. Genetic mutation of the disease is on MEFV gene located on short arm of Chromosome 16. The disease is diagnosed based on clinical evaluation. Amyloidosis is the most important complication. The only agent that decreases the development of amyloidosis and the frequency and severity of the episodes is colchicine, which has been used for about 40 years. In this review, we aimed to discuss especially the most recent advances about Familial Mediterranean Fever which is commonly seen in our population.

Allergies and Hay Fever

Science.gov (United States)

... ENTCareers Marketplace Find an ENT Doctor Near You Allergies and Hay Fever Allergies and Hay Fever Patient ... life more enjoyable. Why does the body develop allergies? Allergy symptoms appear when the immune system reacts ...

Context dependency and generality of fever in insects

Science.gov (United States)

Stahlschmidt, Z. R.; Adamo, S. A.

2013-07-01

Fever can reduce mortality in infected animals. Yet, despite its fitness-enhancing qualities, fever often varies among animals. We used several approaches to examine this variation in insects. Texas field crickets ( Gryllus texensis) exhibited a modest fever (1 °C increase in preferred body temperature, T pref) after injection of prostaglandin, which putatively mediates fever in both vertebrates and invertebrates, but they did not exhibit fever during chronic exposure to heat-killed bacteria. Further, chronic food limitation and mating status did not affect T pref or the expression of behavioural fever, suggesting limited context dependency of fever in G. texensis. Our meta-analysis of behavioural fever studies indicated that behavioural fever occurs in many insects, but it is not ubiquitous. Thus, both empirical and meta-analytical results suggest that the fever response in insects `is widespread, although certainly not inevitable' (Moore 2002). We highlight the need for future work focusing on standardizing an experimental protocol to measure behavioural fever, understanding the specific mechanism(s) underlying fever in insects, and examining whether ecological or physiological costs often outweigh the benefits of fever and can explain the sporadic nature of fever in insects.

Validation of an IgM antibody capture ELISA based on a recombinant nucleoprotein for identification of domestic ruminants infected with Rift Valley fever virus.

Science.gov (United States)

Williams, Roy; Ellis, Charlotte Elizabeth; Smith, Shirley Jacqueline; Potgieter, Christiaan Abraham; Wallace, David; Mareledwane, Vuyokazi Epipodia; Majiwa, Phelix Antipas Ochola

2011-11-01

The presence of competent vectors in some countries currently free of Rift Valley fever (RVF) and global changes in climate, travel and trade have increased the risk of RVF spreading to new regions and have emphasised the need for accurate and reliable diagnostic tools for early diagnosis during RVF outbreaks. Highly sensitive viral detection systems like PCR have a limited use during outbreaks because of the short duration of viraemia, whereas antibodies like specific IgM which are serological indicators of acute infection, can be detected for up to 50 days after infection. Using the highly conserved and immunogenic recombinant nucleoprotein of RVF virus in an IgM capture ELISA, the risk of laboratory infection associated with traditional serological methods is avoided. The use of pre-coated/pre-blocked ELISA plates and the conjugation of the recombinant nucleoprotein with horseradish peroxidase simplified and shortened the assay procedure. Results showed the assay to be highly reproducible with a lower detection limit equal to that of a commercial competition ELISA. By receiver operating characteristic (ROC) curve analysis the area under curve (AUC) index was determined as 1.0 and the diagnostic sensitivity and specificity at a PP cut-off value of 4.1 as 100% and 99.78% respectively. The results of this study demonstrated that the IgM capture ELISA is a safe, reliable and highly accurate diagnostic tool which can be used on its own or in parallel with other methods for the early diagnosis of RVF virus infection and also for monitoring of immune responses in vaccinated domestic ruminants. Copyright © 2011 Elsevier B.V. All rights reserved.

Rescue of infectious rift valley fever virus entirely from cDNA, analysis of virus lacking the NSs gene, and expression of a foreign gene.

Science.gov (United States)

Ikegami, Tetsuro; Won, Sungyong; Peters, C J; Makino, Shinji

2006-03-01

Rift Valley fever virus (RVFV) (genus Phlebovirus, family Bunyaviridae) has a tripartite negative-strand genome, causes a mosquito-borne disease that is endemic in sub-Saharan African countries and that also causes large epidemics among humans and livestock. Furthermore, it is a bioterrorist threat and poses a risk for introduction to other areas. In spite of its danger, neither veterinary nor human vaccines are available. We established a T7 RNA polymerase-driven reverse genetics system to rescue infectious clones of RVFV MP-12 strain entirely from cDNA, the first for any phlebovirus. Expression of viral structural proteins from the protein expression plasmids was not required for virus rescue, whereas NSs protein expression abolished virus rescue. Mutants of MP-12 partially or completely lacking the NSs open reading frame were viable. These NSs deletion mutants replicated efficiently in Vero and 293 cells, but not in MRC-5 cells. In the latter cell line, accumulation of beta interferon mRNA occurred after infection by these NSs deletion mutants, but not after infection by MP-12. The NSs deletion mutants formed larger plaques than MP-12 did in Vero E6 cells and failed to shut off host protein synthesis in Vero cells. An MP-12 mutant carrying a luciferase gene in place of the NSs gene replicated as efficiently as MP-12 did, produced enzymatically active luciferase during replication, and stably retained the luciferase gene after 10 virus passages, representing the first demonstration of foreign gene expression in any bunyavirus. This reverse genetics system can be used to study the molecular virology of RVFV, assess current vaccine candidates, produce new vaccines, and incorporate marker genes into animal vaccines.

Antimicrobial resistance problems in typhoid fever

Science.gov (United States)

Saragih, R. H.; Purba, G. C. F.

2018-03-01

Typhoid fever (enteric fever) remains a burden in developing countries and a major health problem in Southern and Southeastern Asia. Salmonella typhi (S. typhi), the causative agent of typhoid fever, is a gram-negative, motile, rod-shaped, facultative anaerobe and solely a human pathogen with no animal reservoir. Infection of S. typhi can cause fever, abdominal pain and many worsenonspecific symptoms, including gastrointestinal symptoms suchas nausea, vomiting, constipation, and diarrhea. Chloramphenicol, ampicillin,and cotrimoxazole were the first-recommended antibiotics in treating typhoid fever. In the last two decades though, these three traditional drugs started to show resistance and developed multidrug resistance (MDR) S. typhi strains. In many parts of the world, the changing modes ofpresentation and the development of MDR have made typhoid fever increasingly difficult to treat.The use of first-line antimicrobials had been recommended to be fluoroquinolone as a replacement. However, this wassoonfollowedbyreportsof isolates ofS. typhi showing resistancetofluoroquinolones as well. These antimicrobial resistance problems in typhoid fever have been an alarming situation ever since and need to be taken seriously or else typhoid fever will no longer be taken care completely by administering antibiotics.

Blood meal analysis and virus detection in blood-fed mosquitoes collected during the 2006-2007 Rift Valley fever outbreak in Kenya.

Science.gov (United States)

Lutomiah, Joel; Omondi, David; Masiga, Daniel; Mutai, Collins; Mireji, Paul O; Ongus, Juliette; Linthicum, Ken J; Sang, Rosemary

2014-09-01

Rift Valley fever (RVF) is a zoonosis of domestic ruminants in Africa. Blood-fed mosquitoes collected during the 2006-2007 RVF outbreak in Kenya were analyzed to determine the virus infection status and animal source of the blood meals. Blood meals from individual mosquito abdomens were screened for viruses using Vero cells and RT-PCR. DNA was also extracted and the cytochrome c oxidase 1 (CO1) and cytochrome b (cytb) genes amplified by PCR. Purified amplicons were sequenced and queried in GenBank and Barcode of Life Database (BOLD) to identify the putative blood meal sources. The predominant species in Garissa were Aedes ochraceus, (n=561, 76%) and Ae. mcintoshi, (n=176, 24%), and Mansonia uniformis, (n=24, 72.7%) in Baringo. Ae. ochraceus fed on goats (37.6%), cattle (16.4%), donkeys (10.7%), sheep (5.9%), and humans (5.3%). Ae. mcintoshi fed on the same animals in almost equal proportions. RVFV was isolated from Ae. ochraceus that had fed on sheep (4), goats (3), human (1), cattle (1), and unidentified host (1), with infection and dissemination rates of 1.8% (10/561) and 50% (5/10), respectively, and 0.56% (1/176) and 100% (1/1) in Ae. mcintoshi. In Baringo, Ma. uniformis fed on sheep (38%), frogs (13%), duikers (8%), cattle (4%), goats (4%), and unidentified hosts (29%), with infection and dissemination rates of 25% (6/24) and 83.3% (5/6), respectively. Ndumu virus (NDUV) was also isolated from Ae. ochraceus with infection and dissemination rates of 2.3% (13/561) and 76.9% (10/13), and Ae. mcintoshi, 2.8% (5/176) and 80% (4/5), respectively. Ten of the infected Ae. ochraceus had fed on goats, sheep (1), and unidentified hosts (2), and Ae. mcintoshi on goats (3), camel (1), and donkey (1). This study has demonstrated that RVFV and NDUV were concurrently circulating during the outbreak, and sheep and goats were the main amplifiers of these viruses respectively.

Paleoseismology of the Southern Section of the Black Mountains and Southern Death Valley Fault Zones, Death Valley, United States

Science.gov (United States)

Sohn, Marsha S.; Knott, Jeffrey R.; Mahan, Shannon

2014-01-01

The Death Valley Fault System (DVFS) is part of the southern Walker Lane–eastern California shear zone. The normal Black Mountains Fault Zone (BMFZ) and the right-lateral Southern Death Valley Fault Zone (SDVFZ) are two components of the DVFS. Estimates of late Pleistocene-Holocene slip rates and recurrence intervals for these two fault zones are uncertain owing to poor relative age control. The BMFZ southernmost section (Section 1W) steps basinward and preserves multiple scarps in the Quaternary alluvial fans. We present optically stimulated luminescence (OSL) dates ranging from 27 to 4 ka of fluvial and eolian sand lenses interbedded with alluvial-fan deposits offset by the BMFZ. By cross-cutting relations, we infer that there were three separate ground-rupturing earthquakes on BMFZ Section 1W with vertical displacement between 5.5 m and 2.75 m. The slip-rate estimate is ∼0.2 to 1.8 mm/yr, with an earthquake recurrence interval of 4,500 to 2,000 years. Slip-per-event measurements indicate Mw 7.0 to 7.2 earthquakes. The 27–4-ka OSL-dated alluvial fans also overlie the putative Cinder Hill tephra layer. Cinder Hill is offset ∼213 m by SDVFZ, which yields a tentative slip rate of 1 to 8 mm/yr for the SDVFZ.

Morphometric differences in debris flow and mixed flow fans in eastern Death Valley, CA

Science.gov (United States)

Wasklewicz, T. A.; Whitworth, J.

2004-12-01

Geomorphological features are best examined through direct measurement and parameterization of accurate topographic data. Fine-scale data are therefore required to produce a complete set of elevation data. Airborne Laser Swath Mapping (ALSM) data provide high-resolution data over large spatially continuous areas. The National Center for Advanced Laser Mapping (NCALM) collected ALSM data for an area along the eastern side of Death Valley extending from slightly north of Badwater to Mormon Point. The raw ALSM data were post-processed and delivered by NCALM in one-meter grid nodes that we converted to one-meter raster data sets. ALSM data are used to assess variations in the dimensions of surficial features found in 32 alluvial fans (21 debris flow and 11 mixed flow fans). Planimetric curvature of the fan surfaces is used to develop a topographic signature to distinguish debris flow from mixed flow fans. These two groups of fans are identified from field analysis of near vertical exposures along channels as well as surficial exposures at proximal, medial, and distal fan locations. One group of fans exhibited debris flow characteristics (DF), while the second group contained a mixture of fluid and debris flows (MF). Local planimetric curvature of the alluvial fan surfaces was derived from the one-meter DEM. The local curvature data were reclassified into concave and convex features. This sequence corresponds to two broad classes of fan features: channels and interfluves. Thirty random points were generated inside each fan polygon. The length of the nearest concave-convex (channel-interfluve) couplet was measured at each point and the percentage of convex and concave pixels in a 10m box centered on the random point was also recorded. Plots and statistical analyses of the data show clear indication that local planimetric curvature can be used as a topographic signature to distinguish between the varying formative processes in alluvial fans. Significant differences in the

Geomorphological characteristics of increased landslide activity in the Gudbrandsdalen valley, Norway

Science.gov (United States)

Heyerdahl, Håkon; Høydal, Øyvind

2016-04-01

The Gudbrandsdalen valley in Eastern Norway lies in a region where annual precipitation is generally low (down to 300 mm/year). The landslide activity has consequently historically been low, although the lower part of the valley sides generally is draped with thick layers of Quaternary deposits, primarily of glacial or glaciofluvial origin. The perception of natural hazards in the valley was previously primarily connected to flooding in the main river in the valley bottom during early summer, due to large discharges resulting from snowmelt in the mountainous regions west and east of the valley. However, several high-intensity events have changed the image of the region. Starting with a localized, but intense, landslide event in the Northern part of the valley in year 2008, two larger events covering almost the entire valley occurred in the years 2011 and 2013. A high number of landslides was triggered in all these events, including many flash floods and debris flows/debris slides in small and steep tributary rivers along the valley slopes. Landslide triggering covers different release mechanisms: In 2008, landslides were triggered without precipitation in not-frozen soil deposits without snow cover in the lower part of the valley. Groundwater flow through the permeable bedrock ("Otta schist") resulting from snow-melt in the elevated mountainous areas caused landslide triggering due to positive pore-water pressures forming at the bedrock surface below soil deposits, or at depressions in the terrain. Subsequent rainfall resulted in even more landslides being released. In later events (years 2011 and 2013) many landslides were caused by surface water taking new paths downslope, often due to man-made changes in existing waterways (typically poorly planned drainage solutions or new roads). Relatively small discharges in slopes with unconsolidated and easily erodible glacial deposits (typically lateral moraine) in many cases lead to small initial slides that down

Latest Pleistocene and Holocene glacial events in the Colonia valley, Northern Patagonia Icefield, southern Chile

Science.gov (United States)

Nimick, David A.; Mcgrath, Daniel; Mahan, Shannon; Friesen, Beverly A.; Leidich, Jonathan

2016-01-01

The Northern Patagonia Icefield (NPI) is the primary glaciated terrain worldwide at its latitude (46.5–47.5°S), and constraining its glacial history provides unique information for reconstructing Southern Hemisphere paleoclimate. The Colonia Glacier is the largest outlet glacier draining the eastern NPI. Ages were determined using dendrochronology, lichenometry, radiocarbon, cosmogenic 10Be and optically stimulated luminescence. Dated moraines in the Colonia valley defined advances at 13.2 ± 0.95, 11.0 ± 0.47 and 4.96 ± 0.21 ka, with the last being the first constraint on the onset of Neoglaciation for the eastern NPI from a directly dated landform. Dating in the tributary Cachet valley, which contains an ice-dammed lake during periods of Colonia Glacier expansion, defined an advance at ca. 2.95 ± 0.21 ka, periods of advancement at 810 ± 49 cal a BP and 245 ± 13 cal a BP, and retreat during the intervening periods. Recent Colonia Glacier thinning, which began in the late 1800s, opened a lower-elevation outlet channel for Lago Cachet Dos in ca. 1960. Our data provide the most comprehensive set of Latest Pleistocene and Holocene ages for a single NPI outlet glacier and expand previously developed NPI glacial chronologies.

Hemorrhagic Fevers - Multiple Languages

Science.gov (United States)

... dialect) (繁體中文) Expand Section Vaccine Information Statement (VIS) -- Yellow Fever Vaccine: What You Need to Know - English PDF Vaccine Information Statement (VIS) -- Yellow Fever Vaccine: What You Need to Know - 繁體中文 (Chinese, Traditional ( ...

Need yellow fever vaccine? Plan ahead

Science.gov (United States)

... Submit What's this? Submit Button Past Emails Need yellow fever vaccine? Plan ahead. Language: English (US) Español (Spanish) ... none were from the United States). What is yellow fever? Yellow fever is caused by a virus that ...

Rocky Mountain Spotted Fever

Science.gov (United States)

... with facebook share with twitter share with linkedin Rocky Mountain Spotted Fever Credit: CDC A male cayenne tick, Amblyomma cajennense, ... and New Mexico. Why Is the Study of Rocky Mountain Spotted Fever a Priority for NIAID? Tickborne diseases are becoming ...

Valley polarization in bismuth

Science.gov (United States)

Fauque, Benoit

2013-03-01

The electronic structure of certain crystal lattices can contain multiple degenerate valleys for their charge carriers to occupy. The principal challenge in the development of valleytronics is to lift the valley degeneracy of charge carriers in a controlled way. In bulk semi-metallic bismuth, the Fermi surface includes three cigar-shaped electron valleys lying almost perpendicular to the high symmetry axis known as the trigonal axis. The in-plane mass anisotropy of each valley exceeds 200 as a consequence of Dirac dispersion, which drastically reduces the effective mass along two out of the three orientations. According to our recent study of angle-dependent magnetoresistance in bismuth, a flow of Dirac electrons along the trigonal axis is extremely sensitive to the orientation of in-plane magnetic field. Thus, a rotatable magnetic field can be used as a valley valve to tune the contribution of each valley to the total conductivity. As a consequence of a unique combination of high mobility and extreme mass anisotropy in bismuth, the effect is visible even at room temperature in a magnetic field of 1 T. Thus, a modest magnetic field can be used as a valley valve in bismuth. The results of our recent investigation of angle-dependent magnetoresistance in other semi-metals and doped semiconductors suggest that a rotating magnetic field can behave as a valley valve in a multi-valley system with sizeable mass anisotropy.

Dengue fever: a Wikipedia clinical review

OpenAIRE

Heilman, James M; Wolff, Jacob De; Beards, Graham M; Basden, Brian J

2014-01-01

Dengue fever, also known as breakbone fever, is a mosquito-borne infectious tropical disease caused by the dengue virus. Symptoms include fever, headache, muscle and joint pains, and a characteristic skin rash that is similar to measles. In a small proportion of cases, the disease develops into life-threatening dengue hemorrhagic fever, which results in bleeding, thrombocytopenia, and leakage of blood plasma, or into dengue shock syndrome, in which dangerously low blood pressure occurs. Treat...

International risk of yellow fever spread from the ongoing outbreak in Brazil, December 2016 to May 2017.

Science.gov (United States)

Dorigatti, Ilaria; Hamlet, Arran; Aguas, Ricardo; Cattarino, Lorenzo; Cori, Anne; Donnelly, Christl A; Garske, Tini; Imai, Natsuko; Ferguson, Neil M

2017-07-13

States in south-eastern Brazil were recently affected by the largest Yellow Fever (YF) outbreak seen in a decade in Latin America. Here we provide a quantitative assessment of the risk of travel-related international spread of YF indicating that the United States, Argentina, Uruguay, Spain, Italy and Germany may have received at least one travel-related YF case capable of seeding local transmission. Mitigating the risk of imported YF cases seeding local transmission requires heightened surveillance globally. This article is copyright of The Authors, 2017.

Lassa fever or lassa hemorrhagic fever risk to humans from rodent-borne zoonoses.

Science.gov (United States)

El-Bahnasawy, Mamdouh M; Megahed, Laila Abdel-Mawla; Abdalla Saleh, Hala Ahmed; Morsy, Tosson A

2015-04-01

Viral hemorrhagic fevers (VHFs) typically manifest as rapidly progressing acute febrile syndromes with profound hemorrhagic manifestations and very high fatality rates. Lassa fever, an acute hemorrhagic fever characterized by fever, muscle aches, sore throat, nausea, vomiting, diarrhea and chest and abdominal pain. Rodents are important reservoirs of rodent-borne zoonosis worldwide. Transmission rodents to humans occur by aerosol spread, either from the genus Mastomys rodents' excreta (multimammate rat) or through the close contact with infected patients (nosocomial infection). Other rodents of the genera Rattus, Mus, Lemniscomys, and Praomys are incriminated rodents hosts. Now one may ask do the rodents' ectoparasites play a role in Lassa virus zoonotic transmission. This paper summarized the update knowledge on LHV; hopping it might be useful to the clinicians, nursing staff, laboratories' personals as well as those concerned zoonoses from rodents and rodent control.

Morphological and genetic evolution in eastern populations of the Macrhybopsis aestivalis complex (Cypriniformes: Cyprinidae), with the descriptions of four new species.

Science.gov (United States)

Gilbert, Carter R; Mayden, Richard L; Powers, Steven L

2017-03-30

For many years the North American cyprinid fish Macrhybopsis aestivalis (common name: Speckled Chub) was regarded as a single widespread and morphologically variable species, occurring in rivers throughout much of the Mississippi Valley and geographically adjacent eastern Gulf slope drainages, west to the Rio Grande basin in Texas, New Mexico, and Mexico. Eisenhour (1997) completed a morphological study of western populations of the Speckled Chub, the results of which appeared thereafter in published form (Eisenhour 1999, 2004). He demonstrated the existence of five valid species west of the Mississippi River (aestivalis, marconis, australis, tetranema, hyostoma), of which the name aestivalis was shown to be restricted to the population occurring in the Rio Grande and the geographically adjacent Rio San Fernando system, in northeastern Mexico. Eisenhour (2004) considered populations throughout the middle Mississippi Valley and its major tributaries to be a single morphologically variable species (hyostoma), and he also indicated that populations of Macrhybopsis from eastern Gulf slope drainages may represent a complex of species. Genetic confirmation of Eisenhour's conclusions regarding western species appeared in the publication by Underwood et al. (2003), who also showed that western populations of M. hyostoma, as presently recognized, are genetically much more complex than previously considered.     Meanwhile, the present authors were involved in a companion study of eastern populations of Macrhybopsis, for which a genetic summary of the eastern Gulf coast species was published by Mayden & Powers (2004). Based on their findings, four species were recognized from southeastern drainages (identified as species A-D), although no formal taxonomic descriptions were included. Their genetic data, in combination with meristic, morphometric and other morphological data presented herein, form the basis for a revised classification of eastern Macrhybopsis populations

Aquatic habitats of Canaan Valley, West Virginia: Diversity and environmental threats

Science.gov (United States)

Snyder, C.D.; Young, J.A.; Stout, B. M.

2006-01-01

We conducted surveys of aquatic habitats during the spring and summer of 1995 in Canaan Valley, WV, to describe the diversity of aquatic habitats in the valley and identify issues that may threaten the viability of aquatic species. We assessed physical habitat and water chemistry of 126 ponds and 82 stream sites, and related habitat characteristics to landscape variables such as geology and terrain. Based on our analyses, we found two issues likely to affect the viability of aquatic populations in the valley. The first issue was acid rain and the extent to which it potentially limits the distribution of aquatic and semi-aquatic species, particularly in headwater portions of the watershed. We estimate that nearly 46%, or 56 kilometers of stream, had pH levels that would not support survival and reproduction of Salvelinuw fontinalis (brook trout), one of the most acid-tolerant fishes in the eastern US. The second issue was the influence of Castor canadensis (beaver) activity. In the Canaan Valley State Park portion of the valley, beaver have transformed 4.7 kilometers of stream (approximately 17% of the total) to pond habitat through their dam building. This has resulted in an increase in pond habitat, a decrease in stream habitat, and a fragmented stream network (i.e., beaver ponds dispersed among stream reaches). In addition, beaver have eliminated an undetermined amount of forested riparian area through their foraging activities. Depending on the perspective, beaver-mediated changes can be viewed as positive or negative. Increases in pond habitat may increase habitat heterogeneity with consequent increases in biological diversity. In contrast, flooding associated with beaver activity may eliminate lowland wetlands and associated species, create barriers to fish dispersal, and possibly contribute to low dissolved oxygen levels in the Blackwater River. We recommend that future management strategies for the wildlife refuge be viewed in the context of these two issues

Greening Turner Valley

International Nuclear Information System (INIS)

Byfield, M.

2010-01-01

This article discussed remedial activities undertaken in the Turner Valley. Remedial action in the valley must satisfy the financial concerns of engineers and investors as well as the environmental concerns of residents and regulators. Natural gas production in the Turner Valley began in 1914. The production practices were harmful and wasteful. Soil and water pollution was not considered a problem until recently. The impacts of cumulative effects and other pollution hazards are now being considered as part of many oil and gas environmental management programs. Companies know it is cheaper and safer to prevent pollutants from being released, and more efficient to clean them up quickly. Oil and gas companies are also committed to remediating historical problems. Several factors have simplified remediation plans in the Turner Valley. Area real estate values are now among the highest in Alberta. While the valley residents are generally friendly to the petroleum industry, strong communication with all stakeholders in the region is needed. 1 fig.

Hydrogeologic Framework and Ground Water in Basin-Fill Deposits of the Diamond Valley Flow System, Central Nevada

Science.gov (United States)

Tumbusch, Mary L.; Plume, Russell W.

2006-01-01

The Diamond Valley flow system, an area of about 3,120 square miles in central Nevada, consists of five hydrographic areas: Monitor, Antelope, Kobeh, and Diamond Valleys and Stevens Basin. Although these five areas are in a remote part of Nevada, local government officials and citizens are concerned that the water resources of the flow system eventually could be further developed for irrigation or mining purposes or potentially for municipal use outside the study area. In order to better understand the flow system, the U.S. Geological Survey in cooperation with Eureka, Lander, and Nye Counties and the Nevada Division of Water Resources, is conducting a multi-phase study of the flow system. The principal aquifers of the Diamond Valley flow system are in basin-fill deposits that occupy structural basins comprised of carbonate rocks, siliciclastic sedimentary rocks, igneous intrusive rocks, and volcanic rocks. Carbonate rocks also function as aquifers, but their extent and interconnections with basin-fill aquifers are poorly understood. Ground-water flow in southern Monitor Valley is from the valley margins toward the valley axis and then northward to a large area of discharge by evapotranspiration (ET) that is formed south of a group of unnamed hills near the center of the valley. Ground-water flow from northern Monitor Valley, Antelope Valley, and northern and western parts of Kobeh Valley converges to an area of ground-water discharge by ET in central and eastern Kobeh Valley. Prior to irrigation development in the 1960s, ground-water flow in Diamond Valley was from valley margins toward the valley axis and then northward to a large discharge area at the north end of the valley. Stevens Basin is a small upland basin with internal drainage and is not connected with other parts of the flow system. After 40 years of irrigation pumping, a large area of ground-water decline has developed in southern Diamond Valley around the irrigated area. In this part of Diamond

Treating viral hemorrhagic fever.

NARCIS (Netherlands)

Mairuhu, A.T.; Brandjes, D.P.; Gorp, E. van

2003-01-01

Viral hemorrhagic fevers are illnesses associated with a number of geographically restricted, mostly tropical areas. Over recent decades a number of new hemorrhagic fever viruses have emerged. Advances in our understanding of the pathophysiology of these diseases have improved our initial supportive

Spatio-temporal variation in prevalence of Rift Valley fever: a post-epidemic serum survey in cattle and wildlife in Kenya.

Science.gov (United States)

Lwande, Olivia Wesula; Paul, George Omondi; Chiyo, Patrick I; Ng'ang'a, Eliud; Otieno, Viola; Obanda, Vincent; Evander, Magnus

2015-01-01

Rift Valley fever (RVF) is a fatal arthropod-borne zoonotic disease of livestock and humans. Since the identification of RVF in Kenya in the 1930s, repeated epizootics and epidemics coinciding with El Niño events have occurred in several locations in Africa and Saudi Arabia, causing mass deaths of livestock and humans. RVF is of great interest worldwide because of its negative effect on international livestock trade and its potential to spread globally. The latter is due to the increasing incidence of extreme climatic phenomena caused by global warming, as well as to the increase in global trade and international travel. How RVF is maintained and sustained between epidemics and epizootics is not clearly understood, but it has been speculated that wildlife reservoirs and trans-ovarian transmission in the vector may be important. Several studies have examined the role of wildlife and livestock in isolation or in a limited geographical location within the one country over a short time (usually less than a year). In this study, we examined the seroprevalence of anti-RVF antibodies in cattle and several wildlife species from several locations in Kenya over an inter-epidemic period spanning up to 7 years. A serological survey of immunoglobulin G (IgG) antibodies to RVF using competitive ELISA was undertaken on 297 serum samples from different wildlife species at various locations in Kenya. The samples were collected between 2008 and 2015. Serum was also collected in 2014 from 177 cattle from Ol Pejeta Conservancy; 113 of the cattle were in close contact with wildlife and the other 64 were kept separate from buffalo and large game by an electric fence. The seroprevalence of RVF virus (RVFV) antibody was 11.6% in wildlife species during the study period. Cattle that could come in contact with wildlife and large game were all negative for RVFV. The seroprevalence was relatively high in elephants, rhinoceros, and buffalo, but there were no antibodies in zebras, baboons

PATHOGENETIC MECHANISMS IN EXPERIMENTAL IMMUNE FEVER

Science.gov (United States)

Root, Richard K.; Wolff, Sheldon M.

1968-01-01

When rabbits sensitized to human serum albumin (HSA) are challenged intravenously with specific antigen, fever develops and two transferable pyrogens can be demonstrated in the circulation. The first appears prior to the development of fever and has properties consistent with soluble antigen-antibody complexes. These have been shown to be pyrogenic when prepared in vitro and to produce a state of febrile tolerance when repeatedly administered. The second pyrogen, demonstrable during fever in donor rabbits, appears to be similar to endogenous pyrogen described in other experimental fevers. It is postulated that the formation of antigen-antibody complexes constitutes an important initial phase of the febrile reaction in this type of immune fever. PMID:4873023

Phylogeny of Yellow Fever Virus, Uganda, 2016.

Science.gov (United States)

Hughes, Holly R; Kayiwa, John; Mossel, Eric C; Lutwama, Julius; Staples, J Erin; Lambert, Amy J

2018-08-17

In April 2016, a yellow fever outbreak was detected in Uganda. Removal of contaminating ribosomal RNA in a clinical sample improved the sensitivity of next-generation sequencing. Molecular analyses determined the Uganda yellow fever outbreak was distinct from the concurrent yellow fever outbreak in Angola, improving our understanding of yellow fever epidemiology.

Time since plantation is the most important determining factor for soil erosion rates in vineyards. A case study in the valley of Les Alcusses valley, Eastern Spain

Science.gov (United States)

Rodrígo Comino, Jesús; Keesstra, Saskia; Novara, Agata; García Díaz, Andrés; Jordán, Antonio; Brevik, Eric C.; Cerdà, Artemi

2017-04-01

Vineyards are known to suffer from soil erosion around the world (Novara et al., 2011; 2013; 2015; Rodrigo Comino et al., 2015; Prosdocimi et al., 2016; Rodrigo-Comino et al., 2016a; 2016b, 2016b). As in other crops in the Mediterranean such as citrus (Cerdà et al., 2009), olives (Taguas et al., 2015), persimmon (Cerdà et al., 2016) or apricot (Keesstra et al., 2016) plantations, there is a need to survey the spatial and temporal changes in soil erosion in vineyards. Soil redistribution in agricultural land is determined by human management due to the control it exerts on the vegetation cover and soil properties. This is why the time since plantation is important in soil erosion spatial and temporal distribution. Especially because during the plantation of the saplings, the soil is compacted and all other vegetation is removed. In our experiment we selected four paired plot research sites in the Les Alcusses valley, in Eastern Spain. We selected recently planted vineyards (1-year old) and 40-years old plantations. In total 80 rainfall simulations were performed with an intensity of 55 mm h-1 on small 0.25 m2 circular plots to determine the soil detachment by rainfall. The results show that soil erosion rates in the 40-year old vineyards were high (### a rate??), and in the recently planted ones were extremely high, on average six times higher. Acknowledgements The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n 603498 (RECARE project) and the CGL2013- 47862-C2-1-R and CGL2016-75178-C2-2-R national research projects. References Cerdà, A., González-Pelayo, O., Giménez-Morera, A., Jordán, A., Pereira, P., Novara, A., Brevik, E.C., Prosdocimi, M., Mahmoodabadi, M., Keesstra, S., García Orenes, F., Ritsema, C., 2016. The use of barley straw residues to avoid high erosion and runoff rates on persimmon plantations in Eastern Spain under low frequency - high magnitude

Hydraulic and Geomorphic Assessment of the Merced River and Historic Bridges in Eastern Yosemite Valley, Yosemite National Park, California: Sacramento, California

Science.gov (United States)

Minear, J. Toby; Wright, Scott A.

2013-01-01

The Merced River in the popular and picturesque eastern-most part of Yosemite Valley in Yosemite National Park, California, USA, has been extensively altered since the park was first conceived in 1864. Historical human trampling of streambanks has been suggested as the cause of substantial increases in stream width, and the construction of undersized stone bridges in the 1920s has been suggested as the major factor leading to an increase in overbank flooding due to deposition of bars and islands between the bridges. In response, the National Park Service at Yosemite National Park (YNP) requested a study of the hydraulic and geomorphic conditions affecting the most-heavily influenced part of the river, a 2.4-km reach in eastern Yosemite Valley extending from above the Tenaya Creek and Merced River confluence to below Housekeeping Bridge. As part of the study, present-day conditions were compared to historical conditions and several possible planning scenarios were investigated, including the removal of an elevated road berm and the removal of three undersized historic stone bridges identified by YNP as potential problems: Sugar Pine, Ahwahnee and Stoneman Bridges. This Open-File Report will be superseded at a later date by a Scientific Investigations Report. A two-dimensional hydrodynamic model, the USGS FaSTMECH (Flow and Sediment Transport with Morphological Evolution of Channels) model, within the USGS International River Interface Cooperative (iRIC) model framework, was used to compare the scenarios over a range of discharges with annual exceedance probabilities of 50-, 20-, 10-, and 5- percent. A variety of topographic and hydraulic data sources were used to create the input conditions to the hydrodynamic model, including aerial LiDAR (Light Detection And Ranging), ground-based LiDAR, total station survey data, and grain size data from pebble counts. A digitized version of a historical topographic map created by the USGS in 1919, combined with estimates of

Rocky Mountain spotted fever in Argentina.

Science.gov (United States)

Paddock, Christopher D; Fernandez, Susana; Echenique, Gustavo A; Sumner, John W; Reeves, Will K; Zaki, Sherif R; Remondegui, Carlos E

2008-04-01

We describe the first molecular confirmation of Rickettsia rickettsii, the cause of Rocky Mountain spotted fever (RMSF), from a tick vector, Amblyomma cajennense, and from a cluster of fatal spotted fever cases in Argentina. Questing A. cajennense ticks were collected at or near sites of presumed or confirmed cases of spotted fever rickettsiosis in Jujuy Province and evaluated by polymerase chain reaction assays for spotted fever group rickettsiae. DNA of R. rickettsii was amplified from a pool of A. cajennense ticks and from tissues of one of four patients who died during 2003-2004 after illnesses characterized by high fever, severe headache, myalgias, and petechial rash. The diagnosis of spotted fever rickettsiosis was confirmed in the other patients by indirect immunofluorescence antibody and immunohistochemical staining techniques. These findings show the existence of RMSF in Argentina and emphasize the need for clinicians throughout the Americas to consider RMSF in patients with febrile rash illnesses.

Observations of Air Quality at the Edge of Kathmandu, Nepal, and the Diurnal Cycle of Air Pollution In and Around the Kathmandu Valley

Science.gov (United States)

Panday, A. K.; Prinn, R. G.; Regmi, R. P.

2006-12-01

The Kathmandu Valley is a bowl-shaped basin in the Nepal Himalaya, with a rapidly growing city surrounded by rice fields and steep terraced and forested mountain slopes. The valley's air quality is influenced by urban and rural emissions, nocturnal pooling of cold air, slope winds, and a daily exchange of air through mountain passes. To understand these processes and to inform air pollution policy in Nepal, we have carried out the most comprehensive study of air pollution in Nepal to date. During the 9-month dry season of 2004-2005, we carried out continuous measurements every minute of carbon monoxide, ozone, PM10, wind speed, wind direction, solar radiation, temperature, and humidity on the eastern edge of Kathmandu city, at a site that daily received air from both the city and rural areas. We recorded the diurnal cycle of the vertical temperature structure and stability with temperature loggers on towers and mountains. A sodar measured the mixed layer height and upper-level winds. 24-hour simultaneous bag sampling campaigns on mountain peaks, passes, the rural valley, and within the city provided glimpses of the spatial patterns of the diurnal cycle of CO -- a useful tracer of anthropogenic emissions. We measured winds on mountain passes and ozone on mountain peaks. At our main measurement site we found a daily-recurring pattern of CO and PM10, with an afternoon low showing rural background levels, even though the arriving air had traversed the city. This was followed by an evening peak starting at sunset, a second low late at night, and a morning peak enhanced by re-circulation. Pollutants emitted in the valley only traveled out of the valley between the late morning and sunset. During winter months, rush hour was outside of this period, enhancing the morning and evening peaks. Within the city, ozone dropped to zero at night. At mid-day we observed an ozone peak enhanced by photochemical production when the air mass that had been stagnant over the city swept

Effects of Groundwater Development on Uranium: Central Valley, California, USA

Science.gov (United States)

Jurgens, B.C.; Fram, M.S.; Belitz, K.; Burow, K.R.; Landon, M.K.

2010-01-01

Uranium (U) concentrations in groundwater in several parts of the eastern San Joaquin Valley, California, have exceeded federal and state drinking water standards during the last 20 years. The San Joaquin Valley is located within the Central Valley of California and is one of the most productive agricultural areas in the world. Increased irrigation and pumping associated with agricultural and urban development during the last 100 years have changed the chemistry and magnitude of groundwater recharge, and increased the rate of downward groundwater movement. Strong correlations between U and bicarbonate suggest that U is leached from shallow sediments by high bicarbonate water, consistent with findings of previous work in Modesto, California. Summer irrigation of crops in agricultural areas and, to lesser extent, of landscape plants and grasses in urban areas, has increased Pco2 concentrations in the soil zone and caused higher temperature and salinity of groundwater recharge. Coupled with groundwater pumping, this process, as evidenced by increasing bicarbonate concentrations in groundwater over the last 100 years, has caused shallow, young groundwater with high U concentrations to migrate to deeper parts of the groundwater system that are tapped by public-supply wells. Continued downward migration of U-affected groundwater and expansion of urban centers into agricultural areas will likely be associated with increased U concentrations in public-supply wells. The results from this study illustrate the potential long-term effects of groundwater development and irrigation-supported agriculture on water quality in arid and semiarid regions around the world. Journal compilation ?? 2009 National Ground Water Association. No claim to original US government works.

Dengue fever: a Wikipedia clinical review.

Science.gov (United States)

Heilman, James M; De Wolff, Jacob; Beards, Graham M; Basden, Brian J

2014-01-01

Dengue fever, also known as breakbone fever, is a mosquito-borne infectious tropical disease caused by the dengue virus. Symptoms include fever, headache, muscle and joint pains, and a characteristic skin rash that is similar to measles. In a small proportion of cases, the disease develops into life-threatening dengue hemorrhagic fever, which results in bleeding, thrombocytopenia, and leakage of blood plasma, or into dengue shock syndrome, in which dangerously low blood pressure occurs. Treatment of acute dengue fever is supportive, with either oral or intravenous rehydration for mild or moderate disease and use of intravenous fluids and blood transfusion for more severe cases. Along with attempts to eliminate the mosquito vector, work is ongoing to develop a vaccine and medications targeted directly at the virus.

Aerosol exposure to Rift Valley fever virus causes earlier and more severe neuropathology in the murine model, which has important implications for therapeutic development.

Directory of Open Access Journals (Sweden)

Christopher Reed

Full Text Available Rift Valley fever virus (RVFV is an important mosquito-borne veterinary and human pathogen that can cause severe disease including acute-onset hepatitis, delayed-onset encephalitis, retinitis and blindness, or a hemorrhagic syndrome. Currently, no licensed vaccine or therapeutics exist to treat this potentially deadly disease. Detailed studies describing the pathogenesis of RVFV following aerosol exposure have not been completed and candidate therapeutics have not been evaluated following an aerosol exposure. These studies are important because while mosquito transmission is the primary means for human infection, it can also be transmitted by aerosol or through mucosal contact. Therefore, we directly compared the pathogenesis of RVFV following aerosol exposure to a subcutaneous (SC exposure in the murine model by analyzing survival, clinical observations, blood chemistry, hematology, immunohistochemistry, and virus titration of tissues. Additionally, we evaluated the effectiveness of the nucleoside analog ribavirin administered prophylactically to treat mice exposed by aerosol and SC. The route of exposure did not significantly affect the survival, chemistry or hematology results of the mice. Acute hepatitis occurred despite the route of exposure. However, the development of neuropathology occurred much earlier and was more severe in mice exposed by aerosol compared to SC exposed mice. Mice treated with ribavirin and exposed SC were partially protected, whereas treated mice exposed by aerosol were not protected. Early and aggressive viral invasion of brain tissues following aerosol exposure likely played an important role in ribavirin's failure to prevent mortality among these animals. Our results highlight the need for more candidate antivirals to treat RVFV infection, especially in the case of a potential aerosol exposure. Additionally, our study provides an account of the key pathogenetic differences in RVF disease following two potential

77 FR 26475 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

Science.gov (United States)

2012-05-04

...EPA is proposing to approve revisions to the Antelope Valley Air Quality Management District (AVAQMD), Eastern Kern Air Pollution Control District (EKAPCD), and Santa Barbara County Air Pollution Control District (SBCAPCD) portions of the California State Implementation Plan (SIP). We are proposing to approve revisions to local rules that define terms used in other air pollution regulations in these areas and a rule rescission that address Petroleum Coke Calcining Operations--Oxides of Sulfur, under the Clean Air Act as amended in 1990 (CAA or the Act).

Dengue fever as a cause of hemophagocytic lymphohistiocytosis.

Science.gov (United States)

Hein, Noely; Bergara, Gabriel Heiser; Moura, Nathalie Bianchini Vieira; Cardoso, Débora Morais; Hirose, Maki; Ferronato, Angela Espósito; Pastorino, Antônio Carlos; Lo, Denise Swei; Gilio, Alfredo Elias

2015-01-01

Dengue is endemic in more than 100 countries in Southeast Asia, the Americas, the western Pacific, Africa and the eastern Mediterranean regions. The virus is transmitted by Aedes mosquitoes. Dengue disease is the most prevalent arthropod-borne viral disease in humans and is a global and national public health concern in several countries. A seasonal pattern of dengue disease is consistently observed. The highest incidences usually correspond to the period of highest rainfall and humidity, providing suitable conditions for Aedes aegypti breeding and survival. In Brazil for instance it is from January to June. Dengue may cause marked changes in bone marrow that result in hypocellularity and, consequently, thrombocytopenia and leucopenia, along with an increase in hematocrit, which is secondary to capillary leakage. However, those abnormalities are usually self-limited, and do not warrant further investigations, such as a marrow biopsy or a myelogram. The occurrence of persistent reactive hemophagocytosis is uncommon and usually leads to serious adverse outcomes. The authors report the case of an 8-year old girl complaining of high-grade fever, malaise, headache, abdominal pain and a cutaneous rash. Laboratory examination revealed atypical lymphocytosis on peripheral blood count, hyperbilirrunemia, abnormal liver enzymes and clotting tests. Serology was positive for dengue. Because of the persistence of fever and laboratory examinations were consistent with hemophagocytic lymphohistiocytosis (HLH) a bone marrow aspiration was performed, which confirmed the presence of hemophagocytosis. Hence we report a rare presentation of dengue accompanied by self-limited HLH that hopefully evolve to favorable outcome.

Evolutionary and molecular analysis of the emergent severe fever with thrombocytopenia syndrome virus.

Science.gov (United States)

Lam, Tommy Tsan-Yuk; Liu, Wei; Bowden, Thomas A; Cui, Ning; Zhuang, Lu; Liu, Kun; Zhang, Yao-Yun; Cao, Wu-Chun; Pybus, Oliver G

2013-03-01

In 2009, a novel Bunyavirus, called severe fever with thrombocytopenia syndrome virus (SFTSV) was identified in the vicinity of Huaiyangshan, China. Clinical symptoms of this zoonotic virus included severe fever, thrombocytopenia, and leukocytopenia, with a mortality rate of ~10%. By the end of 2011 the disease associated with this pathogen had been reported from eleven Chinese provinces and human-to-human transmission suspected. However, current understanding of the evolution and molecular epidemiology of SFTSV before and after its identification is limited. To address this we undertake phylogenetic, evolutionary and structural analyses of all available SFTSV genetic sequences, including a new SFTSV complete genome isolated from a patient from Henan in 2011. Our discovery of a mosaic L segment sequence, which is descended from two major circulating lineages of SFTSV in China, represents the first evidence that homologous recombination plays a role in SFTSV evolution. Selection analyses indicate that negative selection is predominant in SFTSV genes, yet differences in selective forces among genes are consistent between Phlebovirus species. Further analysis reveals structural conservation between SFTSV and Rift Valley fever virus in the residues of their nucleocapsids that are responsible for oligomerisation and RNA-binding, suggesting the viruses share similar modes of higher-order assembly. We reconstruct the epidemic history of SFTSV using molecular clock and coalescent-based methods, revealing that the extant SFTSV lineages originated 50-150 years ago, and that the viral population experienced a recent growth phase that concurs with and extends the earliest serological reports of SFTSV infection. Taken together, our combined structural and phylogenetic analyses shed light into the evolutionary behaviour of SFTSV in the context of other, better-known, pathogenic Phleboviruses. Copyright © 2012 Elsevier B.V. All rights reserved.

Valley-filtered edge states and quantum valley Hall effect in gated bilayer graphene.

Science.gov (United States)

Zhang, Xu-Long; Xu, Lei; Zhang, Jun

2017-05-10

Electron edge states in gated bilayer graphene in the quantum valley Hall (QVH) effect regime can carry both charge and valley currents. We show that an interlayer potential splits the zero-energy level and opens a bulk gap, yielding counter-propagating edge modes with different valleys. A rich variety of valley current states can be obtained by tuning the applied boundary potential and lead to the QVH effect, as well as to the unbalanced QVH effect. A method to individually manipulate the edge states by the boundary potentials is proposed.

Review of current typhoid fever vaccines, cross-protection against paratyphoid fever, and the European guidelines.

Science.gov (United States)

Zuckerman, Jane N; Hatz, Christoph; Kantele, Anu

2017-10-01

Typhoid and paratyphoid fever remain a global health problem, which - in non-endemic countries - are mainly seen in travelers, particularly in VFRs (visiting friends and relatives), with occasional local outbreaks occurring. A rise in anti-microbial resistance emphasizes the role of preventive measures, especially vaccinations against typhoid and paratyphoid fever for travelers visiting endemic countries. Areas covered: This state-of-the-art review recapitulates the epidemiology and mechanisms of disease of typhoid and paratyphoid fever, depicts the perspective of non-endemic countries and travelers (VFRs), and collectively presents current European recommendations for typhoid fever vaccination. We provide a brief overview of available (and developmental) vaccines in Europe, present current data on cross-protection to S. Paratyphi, and aim to provide a background for typhoid vaccine decision-making in travelers. Expert commentary: European recommendations are not harmonized. Experts must assess vaccination of travelers based on current country-specific recommendations. Travel health practitioners should be aware of the issues surrounding vaccination of travelers and be motivated to increase awareness of typhoid and paratyphoid fever risks.

77 FR 26448 - Revisions to the California State Implementation Plan, Antelope Valley Air Quality Management...

Science.gov (United States)

2012-05-04

...EPA is taking direct final action to approve revisions to the Antelope Valley Air Quality Management District (AVAQMD), Eastern Kern Air Pollution Control District (EKAPCD), and Santa Barbara County Air Pollution Control District (SBCAPCD) portions of the California State Implementation Plan (SIP). Under authority of the Clean Air Act as amended in 1990 (CAA or the Act), we are approving local rules that define terms used in other air pollution regulation in these areas and approving a rule rescission that addresses Petroleum Coke Calcining Operations--Oxides of Sulfur.

Typhoid fever: case report and literature review.

Science.gov (United States)

Sanhueza Palma, Natalia Carolina; Farías Molina, Solange; Calzadilla Riveras, Jeannette; Hermoso, Amalia

2016-06-21

Typhoid fever remains a major health problem worldwide, in contrast to Chile, where this disease is an isolated finding. Clinical presentation is varied, mainly presenting with fever, malaise, abdominal discomfort, and nonspecific symptoms often confused with other causes of febrile syndrome. We report a six-year-old, male patient presenting with fever of two weeks associated with gastrointestinal symptoms, malaise, hepatomegaly and elevated liver enzymes. Differential diagnoses were considered and a Widal reaction and two blood cultures were requested; both came back positive, confirming the diagnosis of typhoid fever caused by Salmonella typhi. Prior to diagnosis confirmation, empirical treatment was initiated with ceftriaxone and metronidazole, with partial response; then drug therapy was adjusted according to ciprofloxacin susceptibility testing with a favorable clinical response. We discuss diagnostic methods and treatment of enteric fever with special emphasis on typhoid fever.

Petrotectonic characteristics, geochemistry, and U-Pb geochronology of Jurassic plutons in the Upper Magdalena Valley-Colombia: Implications on the evolution of magmatic arcs in the NW Andes

Science.gov (United States)

Rodríguez, G.; Arango, M. I.; Zapata, G.; Bermúdez, J. G.

2018-01-01

Field, petrographic, and geochemical characterization along with U-Pb zircon geochronology of the Jurassic plutons exposed in the Upper Magdalena Valley (Colombia) allowed recognizing distinct western and eastern suites formed in at least three magmatic pulses. The western plutons crop out between the eastern flank of the Central Cordillera and the Las Minas range, being limited by the Avirama and the Betania-El Agrado faults. The western suite comprises a quartz monzonite - quartz monzodiorite - quartz diorite series and subordinate monzogranites. Chemically, the rocks are high-K calc-alkaline I-type granitoids (some reaching the shoshonitic series) with metaluminous of magnesium affinity. Trace-element tectonic discrimination is consistent with magmatism in a continental arc environment. Most rocks of this suite crystallized between 195 and 186 Ma (Early Jurassic, Pliensbachian), but locally some plutons yielded younger ages between 182 and 179 Ma (Early Jurassic, Toarcian). The eastern suite crops out in the eastern margin of the Upper Magdalena Valley, east of the Betania - El Agrado fault. Plutons of this unit belong to the monzogranite series with rock types ranging between syenogranites and granodiorites. They are high-K calc-alkaline continental granitoids, some metaluminous and some peraluminous, related to I-type granites generated in a volcanic arc. Crystallization of the suite was between 173 and 169 Ma (Middle Jurassic, Aalenian-Bajocian), but locally these rocks contain zircon with earlier inherited ages related to the magmatic pulse of the western suite between 182 and 179 Ma (Early Jurassic, Toarcian). The evolution of the Jurassic plutons in the Upper Magdalena Valley is best explained by onset or increase in subduction erosion of the accretionary prism. This explains the eastward migration of the arc away from the trench. Subduction of prism sediments increased the water flux from the subducting slab, decreasing solidus temperatures, therefore

Isotopes and Sustainability of the Shallow Groundwater System in Spring and Snake Valleys, Eastern White Pine County, Nevada

Science.gov (United States)

Acheampong, S. Y.

2007-12-01

A critical component to managing water resources is understanding the source of ground water that is extracted from a well. Detail information on the source of recharge and the age of groundwater is thus vital for the proper assessment, development, management, and monitoring of the groundwater resources in an area. Great differences in the isotopic composition of groundwater in a basin and the basin precipitation imply that the groundwater in the basin originates from a source outside the basin or is recharged under different climatic conditions. The stable isotopes of oxygen and hydrogen in precipitation were compared with the isotopic composition of water from wells, springs, and creeks to evaluate the source of the shallow groundwater recharge in Spring and Snake Valleys, Nevada, as part of an evaluation of the water resources in the area. Delta deuterium and delta oxygen-18 composition of springs, wells, creeks, and precipitation in Spring and Snake Valleys show that groundwater recharge occurs primarily from winter precipitation in the surrounding mountains. The carbon-14 content of the groundwater ranged from 30 to 95 percent modern carbon (pmc). Twenty two of the thirty samples had carbon-14 values of greater than 50 pmc. The relatively high carbon-14 values suggest that groundwater in the area is recharged by modern precipitation and the waters have rapid travel times. Total dissolved solids content of the samples outside the playa areas are generally low, and suggests that the water has a relatively short travel time between the recharge areas and sample sites. The presence of tritium in some of the springs and wells also indicate that groundwater mixes with post 1952 precipitation. Hydrogen bomb tests which began in 1952 in the northern hemisphere added large amounts of tritium to the atmosphere and reached a peak in 1963. The stable isotopic composition, the high carbon-14 activities, and the presence of tritium, show that the shallow groundwater in

CAREGIVERS' KNOWLEDGE AND HOME MANAGEMENT OF FEVER IN CHILDREN.

Science.gov (United States)

Koech, P J; Onyango, F E; Jowi, C

2014-05-01

Fever is one of the most common complaints presented to the Paediatric Emergency Unit (PEU). It is a sign that there is an underlying pathologic process, the most common being infection. Many childhood illnesses are accompanied by fever, many of which are treated at home prior to presentation to hospital. Most febrile episodes are benign. Caregivers are the primary contacts to children with fever. Adequate caregivers' knowledge and proper management of fever at home leads to better management of febrile illnesses and reduces complications. To determine the caregivers' knowledge and practices regarding fever in children. A cross-sectional study. Peadiatric Emergency Unit at Kenyatta National Hospital (KNH) SUBJECTS: Two hundred and fifty caregivers of children under 12 years presenting with fever in August to October 2011 to the PEU. Three quarters of the caregivers' defined fever correctly. Their knowledge on the normal body was at 47.6%. Infection was cited as the leading cause of fever (95.2%). Brain damage (77.6%) and dehydration (65.6%) were viewed as the most common complication. Fever was treated at home by 97.2% of caregivers, most of them used medication. Fever was defined correctly by 75.2% of the study participants and a majority of them used touch to detect fever. Fever was managed at home with medications. Public Health Education should be implemented in order to enlighten caregivers on fever and advocate for the use of a clinical thermometer to monitor fever at home.

Rift Valley fever vector diversity and impact of meteorological and environmental factors on Culex pipiens dynamics in the Okavango Delta, Botswana.

Science.gov (United States)

Pachka, Hammami; Annelise, Tran; Alan, Kemp; Power, Tshikae; Patrick, Kgori; Véronique, Chevalier; Janusz, Paweska; Ferran, Jori

2016-08-08

In Northern Botswana, rural communities, livestock, wildlife and large numbers of mosquitoes cohabitate around permanent waters of the Okavango Delta. As in other regions of sub-Saharan Africa, Rift Valley Fever (RVF) virus is known to circulate in that area among wild and domestic animals. However, the diversity and composition of potential RVF mosquito vectors in that area are unknown as well as the climatic and ecological drivers susceptible to affect their population dynamics. Using net traps baited with carbon dioxide, monthly mosquito catches were implemented over four sites surrounding cattle corrals at the northwestern border of the Okavango Delta between 2011 and 2012. The collected mosquito species were identified and analysed for the presence of RVF virus by molecular methods. In addition, a mechanistic model was developed to assess the qualitative influence of meteorological and environmental factors such as temperature, rainfall and flooding levels, on the population dynamics of the most abundant species detected (Culex pipiens). More than 25,000 mosquitoes from 32 different species were captured with an overabundance of Cx. pipiens (69,39 %), followed by Mansonia uniformis (20,67 %) and a very low detection of Aedes spp. (0.51 %). No RVF virus was detected in our mosquito pooled samples. The model fitted well the Cx. pipiens catching results (ρ = 0.94, P = 0.017). The spatial distribution of its abundance was well represented when using local rainfall and flooding measures (ρ = 1, P = 0.083). The global population dynamics were mainly influenced by temperature, but both rainfall and flooding presented a significant influence. The best and worst suitable periods for mosquito abundance were around March to May and June to October, respectively. Our study provides the first available data on the presence of potential RVF vectors that could contribute to the maintenance and dissemination of RVF virus in the Okavango Delta. Our model allowed us to

Structural Features of the Seneca Valley Virus Internal Ribosome Entry Site (IRES) Element: a Picornavirus with a Pestivirus-Like IRES

DEFF Research Database (Denmark)

Willcocks, Margaret M.; Locker, Nicolas; Gomwalk, Zarmwa

2011-01-01

The RNA genome of Seneca Valley virus (SVV), a recently identified picornavirus, contains an internal ribosome entry site (IRES) element which has structural and functional similarity to that from classical swine fever virus (CSFV) and hepatitis C virus, members of the FLAVIVIRIDAE: The SVV IRES...... has an absolute requirement for the presence of a short region of virus-coding sequence to allow it to function either in cells or in rabbit reticulocyte lysate. The IRES activity does not require the translation initiation factor eIF4A or intact eIF4G. The predicted secondary structure indicates...

Summary and evaluation of existing geological and geophysical data near prospective surface facilities in Midway Valley, Yucca Mountain Project, Nye County, Nevada

International Nuclear Information System (INIS)

Gibson, J.D.; Swan, F.H.; Wesling, J.R.; Bullard, T.F.; Perman, R.C.; Angell, M.M.; DiSilvestro, L.A.

1992-01-01

Midway Valley, located at the eastern base of the Yucca Mountain in southwestern Nevada, is the preferred location of the surface facilities for the potential high-level nuclear waste repository at Yucca Mountain. One goal in siting these surface facilities is to avoid faults that could produce relative displacements in excess of 5 cm in the foundations of the waste-handling buildings. This study reviews existing geologic and geophysical data that can be used to assess the potential for surface fault rupture within Midway Valley. Dominant tectonic features in Midway Valley are north-trending, westward-dipping normal faults along the margins of the valley: the Bow Ridge fault to the west and the Paintbrush Canyon fault to the east. Published estimates of average Quaternary slip rates for these faults are very low but the age of most recent displacement and the amount of displacement per event are largely unknown. Surface mapping and interpretive cross sections, based on limited drillhole and geophysical data, suggest that additional normal faults, including the postulated Midway Valley fault, may exist beneath the Quaternary/Tertiary fill within the valley. Existing data, however, are inadequate to determine the location, recency, and geometry of this faulting. To confidently assess the potential for significant Quaternary faulting in Midway Valley, additional data are needed that define the stratigraphy and structure of the strata beneath the valley, characterize the Quaternary soils and surfaces, and establish the age of faulting. The use of new and improved geophysical techniques, combined with a drilling program, offers the greatest potential for resolving subsurface structure in the valley. Mapping of surficial geologic units and logging of soil pits and trenches within these units must be completed, using accepted state-of-the-art practices supported by multiple quantitative numerical and relative age-dating techniques

Mechanism of fever induction in rabbits.

Science.gov (United States)

Siegert, R; Philipp-Dormston, W K; Radsak, K; Menzel, H

1976-01-01

Three exogenous pyrogens (Escherichia coli lipopolysaccharide, synthetic double-stranded ribonucleic acid. Newcastle disease virus) were compared with respect to their mechanisms of fever induction in rabbits. All inducers stimulated the production of an endogenous pyrogen demonstrated in the blood as well as prostaglandins of the E group, and of cyclic adenosine 3',5'-monophosphate in the cerebrospinal fluid. The concentrations of these compounds were elevated approximately twofold as compared to the controls. Independently of the mode of induction, the fever reaction could be prevented by pretreatment with 5 mg of cycloheximide per kg, although the three fever mediators were induced as in febrile animals. Consequently, at least one additional fever mediator that is sensitive to a 30 to 50% inhibition of protein synthesis by cycloheximide has to be postulated. The comparable reactions of the rabbits after administration of different pyrogens argues for a similar fever mechanism. In contrast to fever induction there was no stimulation of endogenous pyrogen, prostaglandins of the E group, and cyclic adenosine 3',5'-monophosphate in hyperthermia as a consequence of exposure of the animals to exogenous overheating. Furthermore, hyperthermia could not be prevented by cycloheximide. PMID:185148

Identification of factors for physicians to facilitate early differential diagnosis of scrub typhus, murine typhus, and Q fever from dengue fever in Taiwan.

Science.gov (United States)

Chang, Ko; Lee, Nan-Yao; Ko, Wen-Chien; Tsai, Jih-Jin; Lin, Wei-Ru; Chen, Tun-Chieh; Lu, Po-Liang; Chen, Yen-Hsu

2017-02-01

Dengue fever, rickettsial diseases, and Q fever are acute febrile illnesses with similar manifestations in tropical areas. Early differential diagnosis of scrub typhus, murine typhus, and Q fever from dengue fever may be made by understanding the distinguishing clinical characteristics and the significance of demographic and weather factors. We conducted a retrospective study to identify clinical, demographic, and meteorological characteristics of 454 dengue fever, 178 scrub typhus, 143 Q fever, and 81 murine typhus cases in three Taiwan hospitals. Case numbers of murine typhus and Q fever correlated significantly with temperature and rainfall; the scrub typhus case number was only significantly related with temperature. Neither temperature nor rainfall correlated with the case number of dengue fever. The rarity of dengue fever cases from January to June in Taiwan may be a helpful clue for diagnosis in the area. A male predominance was observed, as the male-to-female rate was 2.1 for murine typhus and 7.4 for Q fever. Multivariate analysis revealed the following six important factors for differentiating the rickettsial diseases and Q fever group from the dengue fever group: fever ≥8 days, alanine aminotransferase > aspartate aminotransferase, platelets >63,000/mL, C-reactive protein >31.9 mg/L, absence of bone pain, and absence of a bleeding syndrome. Understanding the rarity of dengue in the first half of a year in Taiwan and the six differentiating factors may help facilitate the early differential diagnosis of rickettsial diseases and Q fever from dengue fever, permitting early antibiotic treatment. Copyright © 2015. Published by Elsevier B.V.

Valley development on Hawaiian volcanoes

International Nuclear Information System (INIS)

Baker, V.R.; Gulick, V.C.

1987-01-01

Work in progress on Hawaiian drainage evolution indicates an important potential for understanding drainage development on Mars. Similar to Mars, the Hawaiian valleys were initiated by surface runoff, subsequently enlarged by groundwater sapping, and eventually stabilized as aquifers were depleted. Quantitative geomorphic measurements were used to evaluate the following factors in Hawaiian drainage evolution: climate, stream processes, and time. In comparing regions of similar climate, drainage density shows a general increase with the age of the volcani island. With age and climate held constant, sapping dominated valleys, in contrast to runoff-dominated valleys, display the following: lower drainage densities, higher ratios of valley floor width to valley height, and more positive profile concavities. Studies of stream junction angles indicate increasing junction angles with time on the drier leeward sides of the major islands. The quantitative geomorphic studies and earlier field work yielded important insights for Martian geomorphology. The importance of ash mantling in controlling infiltration on Hawaii also seems to apply to Mars. The Hawaiian valley also have implications for the valley networks of Martian heavily cratered terrains

Perinatal Yellow Fever: A Case Report.

Science.gov (United States)

Diniz, Lilian Martins Oliveira; Romanelli, Roberta Maia Castro; de Carvalho, Andréa Lucchesi; Teixeira, Daniela Caldas; de Carvalho, Luis Fernando Andrade; Cury, Verônica Ferreira; Filho, Marcelo Pereira Lima; Perígolo, Graciele; Heringer, Tiago Pires

2018-04-09

An outbreak of yellow fever in Brazil made it possible to assess different presentations of disease such as perinatal transmission. A pregnant woman was admitted to hospital with yellow fever symptoms. She was submitted to cesarean section and died due to fulminant hepatitis. On the 6th day the newborn developed liver failure and died 13 days later. Yellow fever PCR was positive for both.

Classical Swine Fever-An Updated Review.

Science.gov (United States)

Blome, Sandra; Staubach, Christoph; Henke, Julia; Carlson, Jolene; Beer, Martin

2017-04-21

Classical swine fever (CSF) remains one of the most important transboundary viral diseases of swine worldwide. The causative agent is CSF virus, a small, enveloped RNA virus of the genus Pestivirus. Based on partial sequences, three genotypes can be distinguished that do not, however, directly correlate with virulence. Depending on both virus and host factors, a wide range of clinical syndromes can be observed and thus, laboratory confirmation is mandatory. To this means, both direct and indirect methods are utilized with an increasing degree of commercialization. Both infections in domestic pigs and wild boar are of great relevance; and wild boars are a reservoir host transmitting the virus sporadically also to pig farms. Control strategies for epidemic outbreaks in free countries are mainly based on classical intervention measures; i.e., quarantine and strict culling of affected herds. In these countries, vaccination is only an emergency option. However, live vaccines are used for controlling the disease in endemically infected regions in Asia, Eastern Europe, the Americas, and some African countries. Here, we will provide a concise, updated review on virus properties, clinical signs and pathology, epidemiology, pathogenesis and immune responses, diagnosis and vaccination possibilities.

Skin lesions and inoculation eschars at the tick bite site in spotted fever group rickettsioses: experience from a patient series in eastern crete, Greece.

Science.gov (United States)

Germanakis, Antonis; Chochlakis, Dimosthenis; Angelakis, Emmanouil; Tselentis, Yannis; Psaroulaki, Anna

2014-01-01

The main clinical signs and symptoms caused by a rickettsial infection typically begin 6-10 days after the bite and are accompanied by nonspecific findings such as fever, headache and muscle pain. The diagnosis is mainly based on serological tests, however antibody presentation may be delayed, at least at the early stages of the disease, while seroconversion is usually detected 10-15 days after disease onset. Culture is difficult, requires optimized facilities and often proves negative. Under this scope, the presence of a characteristic inoculation eschar at the bite site may prove a useful clinical tool towards the early suspicion and diagnosis/differential diagnosis of tick-borne rickettsioses, even before the onset of rash and fever or serological confirmation. We describe herein the presence of skin lesions and/or an inoculation eschar at the tick bite site in 17 patients diagnosed, by molecular means, as suffering from spotted fever group rickettsioses. The detection of the pathogen's DNA in biopsy samples proved to be a useful means for early rickettsiae detection and identification. Moreover, the presence of an infiltrated erythema always seemed to precede the appearance of an eschar by 2-5 days and the initiation of fever by 1-10 days; these two signs might also prove useful in the context of the final diagnosis. © 2014 S. Karger AG, Basel.

Is the absence or intermittent YF vaccination the major contributor to its persistent outbreaks in eastern Africa?

Science.gov (United States)

Baba, Marycelin Mandu; Ikusemoran, Mayomi

2017-10-28

Despite the availability of a safe and efficacious yellow fever vaccine since 1937, yellow fever remains a public health threat as a re-emerging disease in Africa and South America. We reviewed the trend of reported yellow fever outbreaks in eastern African countries, identified the risk epidemiological factors associated with the outbreaks and assessed the current situation of Yellow Fever vaccination in Africa. Surveillance and case finding for yellow fever in Africa are insufficient primarily due to lack of appropriate diagnostic capabilities, poor health infrastructure resulting in under-recognition, underreporting and underestimation of the disease. Despite these challenges, Ethiopia reported 302,614 cases (30,505 deaths) in 1943-2015, Kenya had 207 cases (38 deaths) in 1992-2016, Sudan experienced 31,750 suspected cases (1855 deaths) from 1940 to 2012 and Uganda had 452 cases (65 deaths) in 1941-2016. Major risk factors associated with past yellow fever outbreaks include climate, human practices and virus genetics. Comparisons between isolates from different outbreaks after 45 years have revealed the genetic stability of the structural proteins of YFV which are the primary targets of the host immune cells. This probably explains why yellow fever 17D vaccine is considered as outstandingly efficacious and safe after being used for 75 years. However, the 14 amino-acid changes among these isolates may have a greater impact on the changing disease epidemiology, virulence and transmission rate. Low population immunity against YF influences outbreak frequency especially in countries where the incorporation of YF vaccination is not combined with mass vaccination campaigns or vaccination is limited to international travellers. Understanding Yellow fever virus epidemiology as determined by its evolution underscores appropriate disease mitigation strategies and immunization policies. Mobilizing scarce resources to enhance population immunity through sufficient

Educational Fever and South Korean Higher Education

Directory of Open Access Journals (Sweden)

Jeong-Kyu Lee

2006-05-01

Full Text Available This paper examines the influence of educational fever on the development of the Republic of Korea education and economy in the context of the cultural history of this country. In order to examine this study, the author explains the concept of educational fever and discusses the relation between Confucianism and education zeal. Educational fever and human capitalization in South Korean higher education are analyzed from a comparative viewpoint. The study evaluates the effects and problems of education fever this country’s current higher education, and it concludes that Koreans’ educational fever has been a core factor by which to achieve the development of the national economy as well as the rapid expansion of higher education.

Multiple virus lineages sharing recent common ancestry were associated with a Large Rift Valley fever outbreak among livestock in Kenya during 2006-2007.

Science.gov (United States)

Bird, Brian H; Githinji, Jane W K; Macharia, Joseph M; Kasiiti, Jacqueline L; Muriithi, Rees M; Gacheru, Stephen G; Musaa, Joseph O; Towner, Jonathan S; Reeder, Serena A; Oliver, Jennifer B; Stevens, Thomas L; Erickson, Bobbie R; Morgan, Laura T; Khristova, Marina L; Hartman, Amy L; Comer, James A; Rollin, Pierre E; Ksiazek, Thomas G; Nichol, Stuart T

2008-11-01

Rift Valley fever (RVF) virus historically has caused widespread and extensive outbreaks of severe human and livestock disease throughout Africa, Madagascar, and the Arabian Peninsula. Following unusually heavy rainfall during the late autumn of 2006, reports of human and animal illness consistent with RVF virus infection emerged across semiarid regions of the Garissa District of northeastern Kenya and southern Somalia. Following initial RVF virus laboratory confirmation, a high-throughput RVF diagnostic facility was established at the Kenyan Central Veterinary Laboratories in Kabete, Kenya, to support the real-time identification of infected livestock and to facilitate outbreak response and control activities. A total of 3,250 specimens from a variety of animal species, including domesticated livestock (cattle, sheep, goats, and camels) and wildlife collected from a total of 55 of 71 Kenyan administrative districts, were tested by molecular and serologic assays. Evidence of RVF infection was found in 9.2% of animals tested and across 23 districts of Kenya, reflecting the large number of affected livestock and the geographic extent of the outbreak. The complete S, M, and/or L genome segment sequence was obtained from a total of 31 RVF virus specimens spanning the entire known outbreak period (December-May) and geographic areas affected by RVF virus activity. Extensive genomic analyses demonstrated the concurrent circulation of multiple virus lineages, gene segment reassortment, and the common ancestry of the 2006/2007 outbreak viruses with those from the 1997-1998 east African RVF outbreak. Evidence of recent increases in genomic diversity and effective population size 2 to 4 years prior to the 2006-2007 outbreak also was found, indicating ongoing RVF virus activity and evolution during the interepizootic/epidemic period. These findings have implications for further studies of basic RVF virus ecology and the design of future surveillance/diagnostic activities, and

Sleeping sickness and its relationship with development and biodiversity conservation in the Luangwa Valley, Zambia.

Science.gov (United States)

Anderson, Neil E; Mubanga, Joseph; Machila, Noreen; Atkinson, Peter M; Dzingirai, Vupenyu; Welburn, Susan C

2015-04-15

The Luangwa Valley has a long historical association with Human African Trypanosomiasis (HAT) and is a recognised geographical focus of this disease. It is also internationally acclaimed for its high biodiversity and contains many valuable habitats. Local inhabitants of the valley have developed sustainable land use systems in co-existence with wildlife over centuries, based on non-livestock keeping practices largely due to the threat from African Animal Trypanosomiasis. Historical epidemics of human sleeping sickness have influenced how and where communities have settled and have had a profound impact on development in the Valley. Historical attempts to control trypanosomiasis have also had a negative impact on conservation of biodiversity.Centralised control over wildlife utilisation has marginalised local communities from managing the wildlife resource. To some extent this has been reversed by the implementation of community based natural resource management programmes in the latter half of the 20(th) century and the Luangwa Valley provides some of the earliest examples of such programmes. More recently, there has been significant uncontrolled migration of people into the mid-Luangwa Valley driven by pressure on resources in the eastern plateau region, encouragement from local chiefs and economic development in the tourist centre of Mfuwe. This has brought changing land-use patterns, most notably agricultural development through livestock keeping and cotton production. These changes threaten to alter the endemically stable patterns of HAT transmission and could have significant impacts on ecosystem health and ecosystem services.In this paper we review the history of HAT in the context of conservation and development and consider the impacts current changes may have on this complex social-ecological system. We conclude that improved understanding is required to identify specific circumstances where win-win trade-offs can be achieved between the conservation of

Autoinflammatory Diseases with Periodic Fevers.

Science.gov (United States)

Sag, Erdal; Bilginer, Yelda; Ozen, Seza

2017-07-01

One purpose of this review was to raise awareness for the new autoinflammatory syndromes. These diseases are increasingly recognized and are in the differential diagnosis of many disease states. We also aimed to review the latest recommendations for the diagnosis, management, and treatment of these patients. Familial Mediterranean fever (FMF), cryopyrin-associated periodic syndrome (CAPS), tumor necrosis factor receptor-associated periodic fever syndrome (TRAPS), and hyperimmunoglobulinemia D and periodic fever syndrome/mevalonate kinase deficiency (HIDS/MVKD) are the more common autoinflammatory diseases that are characterized by periodic fevers and attacks of inflammation. Recently much collaborative work has been done to understand the characteristics of these patients and to develop recommendations to guide the physicians in the care of these patients. These recent recommendations will be summarized for all four diseases. FMF is the most common periodic fever disease. We need to further understand the pathogenesis and the role of single mutations in the disease. Recently, the management and treatment of the disease have been nicely reviewed. CAPS is another interesting disease associated with severe complications. Anti-interleukin-1 (anti-IL-1) treatment provides cure for these patients. TRAPS is characterized by the longest delay in diagnosis; thus, both pediatricians and internists should be aware of the characteristic features and the follow-up of these patients. HIDS/MVKD is another autoinflammatory diseases characterized with fever attacks. The spectrum of disease manifestation is rather large in this disease, and we need further research on biomarkers for the optimal management of these patients.

Antenatal care in practice: an exploratory study in antenatal care clinics in the Kilombero Valley, south-eastern Tanzania

Directory of Open Access Journals (Sweden)

Kessy Flora

2011-05-01

Full Text Available Abstract Background The potential of antenatal care for reducing maternal morbidity and improving newborn survival and health is widely acknowledged. Yet there are worrying gaps in knowledge of the quality of antenatal care provided in Tanzania. In particular, determinants of health workers' performance have not yet been fully understood. This paper uses ethnographic methods to document health workers' antenatal care practices with reference to the national Focused Antenatal Care guidelines and identifies factors influencing health workers' performance. Potential implications for improving antenatal care provision in Tanzania are discussed. Methods Combining different qualitative techniques, we studied health workers' antenatal care practices in four public antenatal care clinics in the Kilombero Valley, south-eastern Tanzania. A total of 36 antenatal care consultations were observed and compared with the Focused Antenatal Care guidelines. Participant observation, informal discussions and in-depth interviews with the staff helped to identify and explain health workers' practices and contextual factors influencing antenatal care provision. Results The delivery of antenatal care services to pregnant women at the selected antenatal care clinics varied widely. Some services that are recommended by the Focused Antenatal Care guidelines were given to all women while other services were not delivered at all. Factors influencing health workers' practices were poor implementation of the Focused Antenatal Care guidelines, lack of trained staff and absenteeism, supply shortages and use of working tools that are not consistent with the Focused Antenatal Care guidelines. Health workers react to difficult working conditions by developing informal practices as coping strategies or "street-level bureaucracy". Conclusions Efforts to improve antenatal care should address shortages of trained staff through expanding training opportunities, including health worker

17DD yellow fever vaccine

Science.gov (United States)

Martins, Reinaldo M.; Maia, Maria de Lourdes S.; Farias, Roberto Henrique G.; Camacho, Luiz Antonio B.; Freire, Marcos S.; Galler, Ricardo; Yamamura, Anna Maya Yoshida; Almeida, Luiz Fernando C.; Lima, Sheila Maria B.; Nogueira, Rita Maria R.; Sá, Gloria Regina S.; Hokama, Darcy A.; de Carvalho, Ricardo; Freire, Ricardo Aguiar V.; Filho, Edson Pereira; Leal, Maria da Luz Fernandes; Homma, Akira

2013-01-01

Objective: To verify if the Bio-Manguinhos 17DD yellow fever vaccine (17DD-YFV) used in lower doses is as immunogenic and safe as the current formulation. Results: Doses from 27,476 IU to 587 IU induced similar seroconversion rates and neutralizing antibodies geometric mean titers (GMTs). Immunity of those who seroconverted to YF was maintained for 10 mo. Reactogenicity was low for all groups. Methods: Young and healthy adult males (n = 900) were recruited and randomized into 6 groups, to receive de-escalating doses of 17DD-YFV, from 27,476 IU to 31 IU. Blood samples were collected before vaccination (for neutralization tests to yellow fever, serology for dengue and clinical chemistry), 3 to 7 d after vaccination (for viremia and clinical chemistry) and 30 d after vaccination (for new yellow fever serology and clinical chemistry). Adverse events diaries were filled out by volunteers during 10 d after vaccination. Volunteers were retested for yellow fever and dengue antibodies 10 mo later. Seropositivity for dengue was found in 87.6% of volunteers before vaccination, but this had no significant influence on conclusions. Conclusion: In young healthy adults Bio-Manguinhos/Fiocruz yellow fever vaccine can be used in much lower doses than usual. International Register ISRCTN 38082350. PMID:23364472

Spatio-temporal variation in prevalence of Rift Valley fever: a post-epidemic serum survey in cattle and wildlife in Kenya

Directory of Open Access Journals (Sweden)

Olivia Wesula Lwande

2015-12-01

Full Text Available Background: Rift Valley fever (RVF is a fatal arthropod-borne zoonotic disease of livestock and humans. Since the identification of RVF in Kenya in the 1930s, repeated epizootics and epidemics coinciding with El Niño events have occurred in several locations in Africa and Saudi Arabia, causing mass deaths of livestock and humans. RVF is of great interest worldwide because of its negative effect on international livestock trade and its potential to spread globally. The latter is due to the increasing incidence of extreme climatic phenomena caused by global warming, as well as to the increase in global trade and international travel. How RVF is maintained and sustained between epidemics and epizootics is not clearly understood, but it has been speculated that wildlife reservoirs and trans-ovarian transmission in the vector may be important. Several studies have examined the role of wildlife and livestock in isolation or in a limited geographical location within the one country over a short time (usually less than a year. In this study, we examined the seroprevalence of anti-RVF antibodies in cattle and several wildlife species from several locations in Kenya over an inter-epidemic period spanning up to 7 years. Methods: A serological survey of immunoglobulin G (IgG antibodies to RVF using competitive ELISA was undertaken on 297 serum samples from different wildlife species at various locations in Kenya. The samples were collected between 2008 and 2015. Serum was also collected in 2014 from 177 cattle from Ol Pejeta Conservancy; 113 of the cattle were in close contact with wildlife and the other 64 were kept separate from buffalo and large game by an electric fence. Results: The seroprevalence of RVF virus (RVFV antibody was 11.6% in wildlife species during the study period. Cattle that could come in contact with wildlife and large game were all negative for RVFV. The seroprevalence was relatively high in elephants, rhinoceros, and buffalo, but

Oroya fever and verruga peruana: bartonelloses unique to South America.

Directory of Open Access Journals (Sweden)

Michael F Minnick

2014-07-01

Full Text Available Bartonella bacilliformis is the bacterial agent of Carrión's disease and is presumed to be transmitted between humans by phlebotomine sand flies. Carrión's disease is endemic to high-altitude valleys of the South American Andes, and the first reported outbreak (1871 resulted in over 4,000 casualties. Since then, numerous outbreaks have been documented in endemic regions, and over the last two decades, outbreaks have occurred at atypical elevations, strongly suggesting that the area of endemicity is expanding. Approximately 1.7 million South Americans are estimated to be at risk in an area covering roughly 145,000 km2 of Ecuador, Colombia, and Peru. Although disease manifestations vary, two disparate syndromes can occur independently or sequentially. The first, Oroya fever, occurs approximately 60 days following the bite of an infected sand fly, in which infection of nearly all erythrocytes results in an acute hemolytic anemia with attendant symptoms of fever, jaundice, and myalgia. This phase of Carrión's disease often includes secondary infections and is fatal in up to 88% of patients without antimicrobial intervention. The second syndrome, referred to as verruga peruana, describes the endothelial cell-derived, blood-filled tumors that develop on the surface of the skin. Verrugae are rarely fatal, but can bleed and scar the patient. Moreover, these persistently infected humans provide a reservoir for infecting sand flies and thus maintaining B. bacilliformis in nature. Here, we discuss the current state of knowledge regarding this life-threatening, neglected bacterial pathogen and review its host-cell parasitism, molecular pathogenesis, phylogeny, sand fly vectors, diagnostics, and prospects for control.

Analysis of Mining-induced Valley Closure Movements

Science.gov (United States)

Zhang, C.; Mitra, R.; Oh, J.; Hebblewhite, B.

2016-05-01

Valley closure movements have been observed for decades in Australia and overseas when underground mining occurred beneath or in close proximity to valleys and other forms of irregular topographies. Valley closure is defined as the inward movements of the valley sides towards the valley centreline. Due to the complexity of the local geology and the interplay between several geological, topographical and mining factors, the underlying mechanisms that actually cause this behaviour are not completely understood. A comprehensive programme of numerical modelling investigations has been carried out to further evaluate and quantify the influence of a number of these mining and geological factors and their inter-relationships. The factors investigated in this paper include longwall positional factors, horizontal stress, panel width, depth of cover and geological structures around the valley. It is found that mining in a series passing beneath the valley dramatically increases valley closure, and mining parallel to valley induces much more closure than other mining orientations. The redistribution of horizontal stress and influence of mining activity have also been recognised as important factors promoting valley closure, and the effect of geological structure around the valley is found to be relatively small. This paper provides further insight into both the valley closure mechanisms and how these mechanisms should be considered in valley closure prediction models.

Trends of major disease outbreaks in the African region, 2003–2007 ...

African Journals Online (AJOL)

... the Integrated Disease Surveillance and Response (IDSR) strategy aimed at ... fevers (e.g. Ebola, Rift Valley fever, Crimean-Congo fever and yellow fever). ... Conclusions: To successfully reduce the levels of morbidity and mortality resulting ...

Rift Valley Fever (RVF)

Science.gov (United States)

... Outbreak Summaries RVF Distribution Map Resources Virus Ecology Posters Language: English (US) French File Formats Help: How do I view different file formats (PDF, DOC, PPT, MPEG) on this site? Adobe PDF file Microsoft PowerPoint file Microsoft Word file Microsoft Excel file Audio/Video file Apple ...

Valley Fever (Coccidioidomycosis) Statistics

Science.gov (United States)

... States, 1998-2012, MMWR 62(12);217-221. Valdivia L, Nix D, Wright M, Lindberg E, Fagan T, Lieberman D, et al. Coccidioidomycosis as a common cause of community-acquired pneumonia. Emerg Infect Dis. 2006 Jun;12(6):958-62. Chang DC, Anderson S, ...

Ophiolitic basement to the Great Valley forearc basin, California, from seismic and gravity data: Implications for crustal growth at the North American continental margin

Science.gov (United States)

Godfrey, N.J.; Beaudoin, B.C.; Klemperer, S.L.; Levander, A.; Luetgert, J.; Meltzer, A.; Mooney, W.; Tréhu, A.

1997-01-01

The nature of the Great Valley basement, whether oceanic or continental, has long been a source of controversy. A velocity model (derived from a 200-km-long east-west reflection-refraction profile collected south of the Mendocino triple junction, northern California, in 1993), further constrained by density and magnetic models, reveals an ophiolite underlying the Great Valley (Great Valley ophiolite), which in turn is underlain by a westward extension of lower-density continental crust (Sierran affinity material). We used an integrated modeling philosophy, first modeling the seismic-refraction data to obtain a final velocity model, and then modeling the long-wavelength features of the gravity data to obtain a final density model that is constrained in the upper crust by our velocity model. The crustal section of Great Valley ophiolite is 7-8 km thick, and the Great Valley ophiolite relict oceanic Moho is at 11-16 km depth. The Great Valley ophiolite does not extend west beneath the Coast Ranges, but only as far as the western margin of the Great Valley, where the 5-7-km-thick Great Valley ophiolite mantle section dips west into the present-day mantle. There are 16-18 km of lower-density Sierran affinity material beneath the Great Valley ophiolite mantle section, such that a second, deeper, "present-day" continental Moho is at about 34 km depth. At mid-crustal depths, the boundary between the eastern extent of the Great Valley ophiolite and the western extent of Sierran affinity material is a near-vertical velocity and density discontinuity about 80 km east of the western margin of the Great Valley. Our model has important implications for crustal growth at the North American continental margin. We suggest that a thick ophiolite sequence was obducted onto continental material, probably during the Jurassic Nevadan orogeny, so that the Great Valley basement is oceanic crust above oceanic mantle vertically stacked above continental crust and continental mantle.

Fatal Yellow Fever in Travelers to Brazil, 2018.

Science.gov (United States)

Hamer, Davidson H; Angelo, Kristina; Caumes, Eric; van Genderen, Perry J J; Florescu, Simin A; Popescu, Corneliu P; Perret, Cecilia; McBride, Angela; Checkley, Anna; Ryan, Jenny; Cetron, Martin; Schlagenhauf, Patricia

2018-03-23

Yellow fever virus is a mosquito-borne flavivirus that causes yellow fever, an acute infectious disease that occurs in South America and sub-Saharan Africa. Most patients with yellow fever are asymptomatic, but among the 15% who develop severe illness, the case fatality rate is 20%-60%. Effective live-attenuated virus vaccines are available that protect against yellow fever (1). An outbreak of yellow fever began in Brazil in December 2016; since July 2017, cases in both humans and nonhuman primates have been reported from the states of São Paulo, Minas Gerais, and Rio de Janeiro, including cases occurring near large urban centers in these states (2). On January 16, 2018, the World Health Organization updated yellow fever vaccination recommendations for Brazil to include all persons traveling to or living in Espírito Santo, São Paulo, and Rio de Janeiro states, and certain cities in Bahia state, in addition to areas where vaccination had been recommended before the recent outbreak (3). Since January 2018, 10 travel-related cases of yellow fever, including four deaths, have been reported in international travelers returning from Brazil. None of the 10 travelers had received yellow fever vaccination.

Detection, isolation, and genetic characterization of Rift Valley fever virus from Anopheles (Anopheles) coustani, Anopheles (Anopheles) squamosus, and Culex (Culex) antennatus of the Haute Matsiatra region, Madagascar.

Science.gov (United States)

Ratovonjato, Jocelyn; Olive, Marie-Marie; Tantely, Luciano Michael; Andrianaivolambo, Lala; Tata, Etienne; Razainirina, Josette; Jeanmaire, Elisabeth; Reynes, Jean-Marc; Elissa, Nohal

2011-06-01

Following veterinary alerts of Rift Valley fever (RVF) in the districts of Fianarantsoa I and II in November 2008 and in the district of Ambalavao in April 2009, entomological and virological investigations were carried out to identify the mosquito species that could act as RVF virus (RVFV) vectors in the region. A total of 12,785 adult mosquitoes belonging to 5 genera and 21 species were collected. After identification, mosquitoes were pooled by species, sex, and female status (fed or unfed) and then stored at -80°C. Of 319 pools of unfed monospecific female mosquito tested by real-time RT-polymerase chain reaction, RVFV was detected in 1 pool of Anopheles coustani, 5 pools of An. squamosus, and 2 pools of Culex antennatus mosquitoes. The virus was isolated in mosquito cell lines from two of the five Real Time-RT-polymerase chain reaction (real time-RT-PCR) positive pools of An. squamosus mosquitoes. From the eight RVFV strains detected, partial S, M, and L genome segments sequences were obtained. The phylogenetic analysis of these sequences showed that the strains circulating in mosquitoes were genetically close to those that circulated in livestock and humans during RVF outbreaks in 2008 and 2009. This study, therefore, provides strong evidence that An. squamosus, An. coustani, and Cx. antennatus could play a role as vectors of the RVFV during the disease outbreaks in 2008-2009. Bioecological, genetic, and RVF transmission studies on these three mosquito species are needed to address this question and thus improve prevention and control of future RVF outbreaks in Madagascar, where these species are present.

Chandipura virus infection causing encephalitis in a tribal population of Odisha in eastern India.

Science.gov (United States)

Dwibedi, Bhagirathi; Sabat, Jyotsnamayee; Hazra, Rupenangshu K; Kumar, Anu; Dinesh, Diwakar Singh; Kar, Shantanu K

2015-01-01

The sudden death of 10 children in a tribal village of Kandhamal district, Odisha in eastern India led to this investigation. We conducted a door-to-door survey to identify cases. Antibodies for Chandipura, Japanese encephalitis, dengue, chikungunya and West Nile viruses were tested by ELISA in probable cases. Chandipura virus RNA was tested from both human blood samples and sand flies by reverse transcriptase polymerase chain reaction. We conducted vector surveys in domestic and peridomestic areas, and collected sand flies. Entomological investigations revealed the presence of Phlebotomus argentipes and Sergentomiya sp. Thirty-five patients presented with fever, 12 of them had altered sensorium including 4 who had convulsions. The blood samples of 21 patients were tested; four samples revealed Chandipura virusspecific IgM antibody. Chandipura virus infection causing encephalitis affected this tribal population in eastern India at 1212 m above sea level. Copyright 2015, NMJI.

Mine water pollution studies in Chapha Incline, Umaria Coalfield, Eastern Madhya Pradesh, India

Energy Technology Data Exchange (ETDEWEB)

Pathak, V.; Banerjee, A.K. [Hari Singh Gour University, Sagar (India). Dept. of Chemistry

1992-06-01

Mining effects physical and chemical changes in the mine environment resulting in water pollution. Based on the geological distribution the coal mines in the state of Madhya Pradesh, the Coalfield can be categorised into three basins Northern, Southern and Satpura. The Northern belt lies along the Sone Valley whilst the Southern one lies within Mahanadi Valley and the Satpura basin lies south of the alluvial tract. Mine water pollution study reported in this paper is concerned with Chapha Incline, Umaria Coalfield in Eastern Madhya Pradesh. The water analysis was carried out on representative samples obtained from the site on pre-Monsoon and post-monsoon seasons, and reference samples were obtained from the area in the vicinity of the site of investigation. The samples were analysed in the laboratory for determining water quality parameters including trace element detection and microbial analyses. The chemical analysis results of mine water are presented in the form of Durov diagrams. 10 refs., 3 figs., 4 tabs.

Dengue fever outbreak: a clinical management experience

International Nuclear Information System (INIS)

Ahmed, S.; Illyas, M.

2008-01-01

To determine the frequency of dengue as a cause of fever and compare the clinical and haematological characteristics of Dengue-probable and Dengue-proven cases. All patients with age above 14 years, who were either hospitalized or treated in medical outdoor clinic due to acute febrile illness, were evaluated for clinical features of Dengue Fever (DF), Dengue haemorrhagic fever (DHF) and Dengue Shock Syndrome (DSS). Patients showing typical clinical features and haematological findings suggestive of Dengue fever (As per WHO criteria) were evaluated in detail for comparison of probable and confirmed cases of Dengue fever. All other cases of acute febrile illness, not showing clinical features or haematological abnormalities of Dengue fever, were excluded. The clinical and laboratory features were recorded on SPSS 11.0 programme and graded where required, for descriptive and statistical analysis. Out of 5200 patients with febrile illness, 107 (2%) presented with typical features of DF, 40/107 (37%) were Dengue-proven while 67/107 (63%) were Dengue-probable. Out of Dengue-proven cases, 38 were of DF and 2 were of DHF. Day 1 temperature ranged from 99-105 degreeC (mean 101 degree C). Chills and rigors were noticed in 86 (80%), myalgia in 67%, headache in 54%, pharyngitis in 35%, rash in 28%, and bleeding manifestations in 2% cases. Hepatomegaly in 1(0.5%), lymphadenopathy in 1 (0.5%) and splenomegaly in 12 (11.2%) cases. Leucopoenia (count 40 U/L in 57% cases. Frequency of clinically suspected dengue virus infection was 107 (2%), while confirmed dengue fever cases were 40 (0.8%) out of 5200 fever cases. Fever with chills and rigors, body aches, headache, myalgia, rash, haemorrhagic manifestations, platelet count, total leukocyte count, and ALT, are parameters to screen the cases of suspected dengue virus infection, the diagnosis cannot be confirmed unless supported by molecular studies or dengue specific IgM. (author)

Q fever: a new ocular manifestation

Directory of Open Access Journals (Sweden)

Udaondo P

2011-09-01

Full Text Available P Udaondo1,3, S Garcia-Delpech1,2, D Salom1,2, M Garcia-Pous1, M Diaz-Llopis1,21Department of Ophthalmology, Nuevo Hospital Universitario y Politecnico La Fe, Valencia, Spain; 2Faculty of Medicine, Universitat de València, Valencia, Spain; 3Universidad Cardenal Herrera CEU, Valencia, SpainAbstract: Q Fever is a zoonosis caused by Coxiella burnetii. Ocular manifestations are rare in this infection. We describe the case of a man complaining of an intense retro-orbital headache, fever, arthralgia, and bilateral loss of vision, who showed an anterior uveitis accompanied by exudative bilateral inferior retinal detachment and optic disk edema. At the beginning, a Vogt–Koyanagi–Harada (VKH syndrome was suspected, but the patient was diagnosed with Q fever and treatment with doxycycline was initiated, with complete resolution after 2 weeks. We wondered if Q fever could unleash VKH syndrome or simulate a VKH syndrome by a similar immunological process.Keywords: Q fever, Vogt–Koyanagi–Harada syndrome, panuveitis, exudative retinal detachment

A Nonfatal Case of Dobrava Hantavirus Hemorrhagic Fever with Renal Syndrome Combined with Hantavirus Cardiopulmonary Syndrome

Directory of Open Access Journals (Sweden)

Shemsedin Dreshaj

2018-01-01

Full Text Available Among hantaviruses (HTNV, 22 are known as pathogenic for humans. HTNV can cause two clinical entities: hemorrhagic fever with renal syndrome (HFRS and hantavirus pulmonary syndrome or hantavirus cardiopulmonary syndrome (HCPS. In most countries of Eastern Europe as well as in Kosovo, HTNV infection is presented mainly as HFRS. Here, we report a 20-year-old man with HFRS and HCPS caused by Dobrava hantavirus strain, successfully treated in Intensive Care Unit of Infectious Diseases Clinic, University Clinical Center of Kosovo. In HFRS endemic areas, patients with acute respiratory distress syndrome need to be evaluated for Dobrava hantavirus strain as a possible causative agent.

Conserved Fever Pathways across Vertebrates: A Herpesvirus Expressed Decoy TNF-α Receptor Delays Behavioral Fever in Fish.

Science.gov (United States)

Rakus, Krzysztof; Ronsmans, Maygane; Forlenza, Maria; Boutier, Maxime; Piazzon, M Carla; Jazowiecka-Rakus, Joanna; Gatherer, Derek; Athanasiadis, Alekos; Farnir, Frédéric; Davison, Andrew J; Boudinot, Pierre; Michiels, Thomas; Wiegertjes, Geert F; Vanderplasschen, Alain

2017-02-08

Both endotherms and ectotherms (e.g., fish) increase their body temperature to limit pathogen infection. Ectotherms do so by moving to warmer places, hence the term "behavioral fever." We studied the manifestation of behavioral fever in the common carp infected by cyprinid herpesvirus 3, a native carp pathogen. Carp maintained at 24°C died from the infection, whereas those housed in multi-chamber tanks encompassing a 24°C-32°C gradient migrated transiently to the warmest compartment and survived as a consequence. Behavioral fever manifested only at advanced stages of infection. Consistent with this, expression of CyHV-3 ORF12, encoding a soluble decoy receptor for TNF-α, delayed the manifestation of behavioral fever and promoted CyHV-3 replication in the context of a temperature gradient. Injection of anti-TNF-α neutralizing antibodies suppressed behavioral fever, and decreased fish survival in response to infection. This study provides a unique example of how viruses have evolved to alter host behavior to increase fitness. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

The Consequences of Reconfiguring the Ambisense S Genome Segment of Rift Valley Fever Virus on Viral Replication in Mammalian and Mosquito Cells and for Genome Packaging

Science.gov (United States)

Elliott, Richard M.

2014-01-01

Rift Valley fever virus (RVFV, family Bunyaviridae) is a mosquito-borne pathogen of both livestock and humans, found primarily in Sub-Saharan Africa and the Arabian Peninsula. The viral genome comprises two negative-sense (L and M segments) and one ambisense (S segment) RNAs that encode seven proteins. The S segment encodes the nucleocapsid (N) protein in the negative-sense and a nonstructural (NSs) protein in the positive-sense, though NSs cannot be translated directly from the S segment but rather from a specific subgenomic mRNA. Using reverse genetics we generated a virus, designated rMP12:S-Swap, in which the N protein is expressed from the NSs locus and NSs from the N locus within the genomic S RNA. In cells infected with rMP12:S-Swap NSs is expressed at higher levels with respect to N than in cells infected with the parental rMP12 virus. Despite NSs being the main interferon antagonist and determinant of virulence, growth of rMP12:S-Swap was attenuated in mammalian cells and gave a small plaque phenotype. The increased abundance of the NSs protein did not lead to faster inhibition of host cell protein synthesis or host cell transcription in infected mammalian cells. In cultured mosquito cells, however, infection with rMP12:S-Swap resulted in cell death rather than establishment of persistence as seen with rMP12. Finally, altering the composition of the S segment led to a differential packaging ratio of genomic to antigenomic RNA into rMP12:S-Swap virions. Our results highlight the plasticity of the RVFV genome and provide a useful experimental tool to investigate further the packaging mechanism of the segmented genome. PMID:24550727

Trapping of Rift Valley Fever (RVF vectors using Light Emitting Diode (LED CDC traps in two arboviral disease hot spots in Kenya

Directory of Open Access Journals (Sweden)

Tchouassi David P

2012-05-01

Full Text Available Abstract Background Mosquitoes’ response to artificial lights including color has been exploited in trap designs for improved sampling of mosquito vectors. Earlier studies suggest that mosquitoes are attracted to specific wavelengths of light and thus the need to refine techniques to increase mosquito captures following the development of super-bright light-emitting diodes (LEDs which emit narrow wavelengths of light or very specific colors. Therefore, we investigated if LEDs can be effective substitutes for incandescent lamps used in CDC light traps for mosquito surveillance, and if so, determine the best color for attraction of important Rift Valley Fever (RFV vectors. Methods The efficiency of selected colored LED CDC light traps (red, green, blue, violet, combination of blue-green-red (BGR to sample RVF vectors was evaluated relative to incandescent light (as control in a CDC light trap in two RVF hotspots (Marigat and Ijara districts in Kenya. In field experiments, traps were baited with dry ice and captures evaluated for Aedes tricholabis, Ae. mcintoshi, Ae. ochraceus, Mansonia uniformis, Mn. africana and Culex pipiens, following Latin square design with days as replicates. Daily mosquito counts per treatment were analyzed using a generalized linear model with Negative Binomial error structure and log link using R. The incidence rate ratios (IRR that mosquito species chose other treatments instead of the control, were estimated. Results Seasonal preference of Ae.mcintoshi and Ae. ochraceus at Ijara was evident with a bias towards BGR and blue traps respectively in one trapping period but this pattern waned during another period at same site with significantly low numbers recorded in all colored traps except blue relative to the control. Overall results showed that higher captures of all species were recorded in control traps compared to the other LED traps (IRR  Conclusion Based on our trapping design and color, none of the LEDs

Rocky Mountain spotted fever, Colombia.

Science.gov (United States)

Hidalgo, Marylin; Orejuela, Leonora; Fuya, Patricia; Carrillo, Pilar; Hernandez, Jorge; Parra, Edgar; Keng, Colette; Small, Melissa; Olano, Juan P; Bouyer, Donald; Castaneda, Elizabeth; Walker, David; Valbuena, Gustavo

2007-07-01

We investigated 2 fatal cases of Rocky Mountain spotted fever that occurred in 2003 and 2004 near the same locality in Colombia where the disease was first reported in the 1930s. A retrospective serosurvey of febrile patients showed that > 21% of the serum samples had antibodies aaainst spotted fever group rickettsiae.

Paediatric fever management: continuing education for clinical nurses.

Science.gov (United States)

Walsh, Anne M; Edwards, Helen E; Courtney, Mary D; Wilson, Jenny E; Monaghan, Sarah J

2006-01-01

This study examined the influence of level of practice, additional paediatric education and length of paediatric and current experience on nurses' knowledge of and beliefs about fever and fever management. Fifty-one nurses from medical wards in an Australian metropolitan paediatric hospital completed a self-report descriptive survey. Knowledge of fever management was mediocre (Mean 12.4, SD 2.18 on 20 items). Nurses practicing at a higher level and those with between one and four years paediatric or current experience were more knowledgeable than novices or more experienced nurses. Negative beliefs that would impact nursing practice were identified. Interestingly, beliefs about fever, antipyretic use in fever management and febrile seizures were similar; they were not influenced by nurses' knowledge, experience, education or level of practice. Paediatric nurses are not expert fever managers. Knowledge deficits and negative attitudes influence their practice irrespective of additional paediatric education, paediatric or current experience or level of practice. Continuing education is therefore needed for all paediatric nurses to ensure the latest clear evidence available in the literature for best practice in fever management is applied.

Rocky Mountain spotted fever in Arizona: documentation of heavy environmental infestations of Rhipicephalus sanguineus at an endemic site.

Science.gov (United States)

Nicholson, William L; Paddock, Christopher D; Demma, Linda; Traeger, Marc; Johnson, Brian; Dickson, Jeffrey; McQuiston, Jennifer; Swerdlow, David

2006-10-01

A recent epidemiologic investigation identified 16 cases and 2 deaths from Rocky Mountain spotted fever (RMSF) in two eastern Arizona communities. Prevalence studies were conducted by collecting free-living ticks (Acari: Ixodidae) from the home sites of RMSF patients and from other home sites within the community. Dry ice traps and flagging confirmed heavy infestations at many of the home sites. Only Rhipicephalus sanguineus ticks were identified and all developmental stages were detected. It is evident that under certain circumstances, this species does transmit Rickettsia rickettsii to humans and deserves reconsideration as a vector in other geographic areas.

The development and adaption of early agriculture in Huanghe River Valley, China

Science.gov (United States)

Li, X.

2017-12-01

The expanding and developing of agriculture are the basic of population growth, the expansions of material cultures and civilization. The Huanghe River valley, as the origin center of millet agriculture, lies between the heartlands of wheat and rice, which gestates the flourishing Neolithic culture based on agriculture. Recent work using botanical remains has greatly expanded the knowledge concerning early agriculture. Here, we report the new progress on the development and adaption of early agriculture in Huanghe River valley and the surrounding areas. Based on the analysis of phytolith from 13 sites in middle reaches of Huanghe River and the survey of crop seeds from 5 sites in Guanzhong Basin, the rice have been cultivated around 7600 cal BP in semi-humid regions dominated by rain-fed agriculture. The mixed agriculture of common millet, foxtail millet, and rice continued to exist between 7600-3500 BP. In semi-arid region of Huanghe River valley, the agriculture was dominated by the production of common and foxtail millet and 3 major changes have taken place around 6500 BP, 5500 BP, and 4000 BP during Neolithic. The cultivating ratio of common and foxtail millet was adjusted by farmer for adapting the climate changes during Holocene. Approximately 5000 yr BP, the rain-fed agriculture continues to break geographical boundaries to expand to west and southwest from Huanghe River valley. Millet agriculture appeared in southern Ganshu and north eastern Tibetan Plateau. The common and foxtail millet spread to the arid-area of Hexi corridor, a major crossroad of the famous Silk Road, around 4500 yr BP. Wheat was added as a new crop to the existing millet based agricultural systems around 4100-4000 cal yr BP in Hexi corridor. Between 3800 and 3400 cal yr BP, the proportion of wheat and barley in agriculture was up to 90%,which have replaced the local millet and become the main crops. And now, some new evidences of wheat agriculture from NW Xijiang have been obtained and

Q Fever: Statistics and Epidemiology

Science.gov (United States)

... Q Fever in the United States Hospitalization Rates Geography Seasonal trends People at Risk Q fever was first recognized as a human disease in Australia in 1935 and in the United States in the early 1940s. The “Q” stands for “query” and was applied at a time when the cause was unknown. ...

Monoacylglycerol Lipase Regulates Fever Response.

Directory of Open Access Journals (Sweden)

Manuel Sanchez-Alavez

Full Text Available Cyclooxygenase inhibitors such as ibuprofen have been used for decades to control fever through reducing the levels of the pyrogenic lipid transmitter prostaglandin E2 (PGE2. Historically, phospholipases have been considered to be the primary generator of the arachidonic acid (AA precursor pool for generating PGE2 and other eicosanoids. However, recent studies have demonstrated that monoacyglycerol lipase (MAGL, through hydrolysis of the endocannabinoid 2-arachidonoylglycerol, provides a major source of AA for PGE2 synthesis in the mammalian brain under basal and neuroinflammatory states. We show here that either genetic or pharmacological ablation of MAGL leads to significantly reduced fever responses in both centrally or peripherally-administered lipopolysaccharide or interleukin-1β-induced fever models in mice. We also show that a cannabinoid CB1 receptor antagonist does not attenuate these anti-pyrogenic effects of MAGL inhibitors. Thus, much like traditional nonsteroidal anti-inflammatory drugs, MAGL inhibitors can control fever, but appear to do so through restricted control over prostaglandin production in the nervous system.

Radiological observation in typhoid fever

Energy Technology Data Exchange (ETDEWEB)

Lim, K Y; Park, H Y; Kim, J D; Rhee, H S [Presbyterian Medical Center, Jeonju (Korea, Republic of)

1985-12-15

Radiographic findings in plain abdominal films, chest PA and liver scanning are considered to be ancillary diagnostic methods for uncomplicated typhoid fever and a valuable method for detection of complication such as intestinal perforation. 189 cases of clinically proven typhoid fever from Mar. 1973 to Feb. 1979 in this Hospital were reviewed and radiographic findings were analyzed carefully. The results are as follows: 1. Most (73.6%) cases were between 20 and 40 years of age. 2. Three of the most common radiographic findings were as follows: 1) Localized paralytic ileus in RLQ or diffuse paralytic ileus (96.3%). 2) Hepatomegaly (56.5%). 3) Splenomegaly (49.7%). 3. In cases of typhoid fever with intestinal perforation there were additional significant findings such as free air under diaphragm (85%), free fluid in peritoneal cavity (90%) and air fluid levels in RLQ (80%). 4. The most frequent chest x-ray finding was elevation of diaphragm (11.1%). 5. 8 cases of complicated typhoid fever which eventually came to operation were diagnosed only by radiographic method.

Radiological observation in typhoid fever

International Nuclear Information System (INIS)

Lim, K. Y.; Park, H. Y.; Kim, J. D.; Rhee, H. S.

1985-01-01

Radiographic findings in plain abdominal films, chest PA and liver scanning are considered to be ancillary diagnostic methods for uncomplicated typhoid fever and a valuable method for detection of complication such as intestinal perforation. 189 cases of clinically proven typhoid fever from Mar. 1973 to Feb. 1979 in this Hospital were reviewed and radiographic findings were analyzed carefully. The results are as follows: 1. Most (73.6%) cases were between 20 and 40 years of age. 2. Three of the most common radiographic findings were as follows: 1) Localized paralytic ileus in RLQ or diffuse paralytic ileus (96.3%). 2) Hepatomegaly (56.5%). 3) Splenomegaly (49.7%). 3. In cases of typhoid fever with intestinal perforation there were additional significant findings such as free air under diaphragm (85%), free fluid in peritoneal cavity (90%) and air fluid levels in RLQ (80%). 4. The most frequent chest x-ray finding was elevation of diaphragm (11.1%). 5. 8 cases of complicated typhoid fever which eventually came to operation were diagnosed only by radiographic method.

Acute infectious purpura fulminans due to probable spotted fever

Directory of Open Access Journals (Sweden)

A Kundavaram

2014-01-01

Full Text Available Purpura fulminans (PF is associated with several infections, most notably with meningococcus, staphylococcus, and streptococcus infections. However, there are few reports of association of this entity with spotted fever from India. We report the case of a 55-year-old man who presented with fever, headache, and myalgia. On the seventh day of fever he developed nonblanching purple hemorrhagic purpura on the trunk and most prominently on the extremities consistent with purpura fulminans. Immunofluorescent assay confirmed the diagnosis of spotted fever. PF though common with rocky mountain spotted fever (RMSF is rarely seen in association with Indian tick typhus, the usual cause of spotted fever in India.

STUDIES ON THE PATHOGENESIS OF FEVER

Science.gov (United States)

Atkins, Elisha; Wood, W. Barry

1955-01-01

Further studies have been made of a pyrogenic substance which appears in the circulation of rabbits during the course of experimental fever induced by injection of typhoid vaccine. With the use of a passive transfer method and pyrogen-tolerant recipients, the biological properties of this substance have been differentiated from those of the uncleared vaccine in the circulation. The newly identified factor resembles leucocytic pyrogen in the rapidity with which it produces fever and in its failure to exhibit cross-tolerance with bacterial pyrogen. This striking similarity of properties suggests that the circulating factor is of endogenous origin and may arise from cell injury. A close correlation between its presence in the circulation and the existence of fever has been demonstrated. The possible relationship of these findings to the pathogenesis of fever is evident. PMID:13271667

Species composition of the vegetation along the Sherichhu River, lower montane area of Eastern Bhutan

Directory of Open Access Journals (Sweden)

Tenzin Jamtsho

2017-06-01

Full Text Available An investigation of the riparian vegetation along the Sherichhu River, lower montane area of Eastern Bhutan was conducted from April to December 2015 to explore the plant communities in terms of species composition. A total number of 18 plots were placed within the remnant patches of the vegetation on either side of the river. In total, 172 species of vascular plant has been recorded. The cluster analysis suggested four types of plant communities in the study area viz., the MallotusDesmodium-Rhus shrubland and the Syzygium venosum woodland communities, which are located in V-shaped valleys and the Albizia-Flueggea woodland and Quercus glauca woodland communities located in U-shaped valleys. In broad-spectrum, the topographic features and environmental variables i.e. litter accumulation and flooding condition might also have some impact on the species composition of the plant communities of this vegetation.

Viscerotropic disease following yellow fever vaccination in Peru.

Science.gov (United States)

Whittembury, Alvaro; Ramirez, Gladys; Hernández, Herminio; Ropero, Alba Maria; Waterman, Steve; Ticona, María; Brinton, Margo; Uchuya, Jorge; Gershman, Mark; Toledo, Washington; Staples, Erin; Campos, Clarense; Martínez, Mario; Chang, Gwong-Jen J; Cabezas, Cesar; Lanciotti, Robert; Zaki, Sherif; Montgomery, Joel M; Monath, Thomas; Hayes, Edward

2009-10-09

Five suspected cases of yellow fever vaccine-associated viscerotropic disease (YEL-AVD) clustered in space and time following a vaccination campaign in Ica, Peru in 2007. All five people received the same lot of 17DD live attenuated yellow fever vaccine before their illness; four of the five died of confirmed YEL-AVD. The surviving case was classified as probable YEL-AVD. Intensive investigation yielded no abnormalities of the implicated vaccine lot and no common risk factors. This is the first described space-time cluster of yellow fever viscerotropic disease involving more than two cases. Mass yellow fever vaccination should be avoided in areas that present extremely low risk of yellow fever.

Epidural Labor Analgesia and Maternal Fever.

Science.gov (United States)

Sharpe, Emily E; Arendt, Katherine W

2017-06-01

Women receiving an epidural for labor analgesia are at increased risk for intrapartum fever. This relationship has been supported by observational, before and after, and randomized controlled trials. The etiology is not well understood but is likely a result of noninfectious inflammation as studies have found women with fever have higher levels of inflammatory markers. Maternal pyrexia may change obstetric management and women are more likely to receive antibiotics or undergo cesarean delivery. Maternal pyrexia is associated with adverse neonatal outcomes. With these consequences, understanding and preventing maternal fever is imperative.

Dengue fever outbreak: a clinical management experience.

Science.gov (United States)

Ahmed, Shahid; Ali, Nadir; Ashraf, Shahzad; Ilyas, Mohammad; Tariq, Waheed-Uz-Zaman; Chotani, Rashid A

2008-01-01

To determine the frequency of dengue as a cause of fever and compare the clinical and haematological characteristics of Dengue-probable and Dengue-proven cases. An observational study. The Combined Military Hospital, Malir Cantt., Karachi, from August 2005 to December 2006. All patients with age above 14 years, who were either hospitalized or treated in medical outdoor clinic due to acute febrile illness, were evaluated for clinical features of Dengue Fever (DF), Dengue haemorrhagic fever (DHF) and Dengue Shock Syndrome (DSS). Patients showing typical clinical features and haematological findings suggestive of Dengue fever (As per WHO criteria) were evaluated in detail for comparison of probable and confirmed cases of Dengue fever. All other cases of acute febrile illness, not showing clinical features or haematological abnormalities of Dengue fever, were excluded. The clinical and laboratory features were recorded on SPSS 11.0 programme and graded where required, for descriptive and statistical analysis. Out of 5200 patients with febrile illness, 107(2%) presented with typical features of DF, 40/107(37%) were Dengue-proven while 67/107(63%) were Dengue-probable. Out of Dengue-proven cases, 38 were of DF and 2 were of DHF. Day 1 temperature ranged from 99-1050C (mean 1010C). Chills and rigors were noticed in 86 (80%), myalgia in 67%, headache in 54%, pharyngitis in 35%, rash in 28%, and bleeding manifestations in 2% cases. Hepatomegaly in 1(0.5%), lymphadenopathy in 1(0.5%) and splenomegaly in 12 (11.2%) cases. Leucopoenia (count40 U/L in 57% cases. Frequency of clinically suspected dengue virus infection was 107 (2%), while confirmed dengue fever cases were 40 (0.8%) out of 5200 fever cases. Fever with chills and rigors, body aches, headache, myalgia, rash, haemorrhagic manifestations, platelet count, total leukocyte count, and ALT, are parameters to screen the cases of suspected dengue virus infection; the diagnosis cannot be confirmed unless supported by

Hospital-based surveillance for viral hemorrhagic fevers and hepatitides in Ghana.

Directory of Open Access Journals (Sweden)

Joseph Humphrey Kofi Bonney

Full Text Available BACKGROUND: Viral hemorrhagic fevers (VHF are acute diseases associated with bleeding, organ failure, and shock. VHF may hardly be distinguished clinically from other diseases in the African hospital, including viral hepatitis. This study was conducted to determine if VHF and viral hepatitis contribute to hospital morbidity in the Central and Northern parts of Ghana. METHODOLOGY/PRINCIPAL FINDINGS: From 2009 to 2011, blood samples of 258 patients with VHF symptoms were collected at 18 hospitals in Ashanti, Brong-Ahafo, Northern, Upper West, and Upper East regions. Patients were tested by PCR for Lassa, Rift Valley, Crimean-Congo, Ebola/Marburg, and yellow fever viruses; hepatitis A (HAV, B (HBV, C (HCV, and E (HEV viruses; and by ELISA for serological hepatitis markers. None of the patients tested positive for VHF. However, 21 (8.1% showed anti-HBc IgM plus HBV DNA and/or HBsAg; 37 (14% showed HBsAg and HBV DNA without anti-HBc IgM; 26 (10% showed anti-HAV IgM and/or HAV RNA; and 20 (7.8% were HCV RNA-positive. None was positive for HEV RNA or anti-HEV IgM plus IgG. Viral genotypes were determined as HAV-IB, HBV-A and E, and HCV-1, 2, and 4. CONCLUSIONS/SIGNIFICANCE: VHFs do not cause significant hospital morbidity in the study area. However, the incidence of acute hepatitis A and B, and hepatitis B and C with active virus replication is high. These infections may mimic VHF and need to be considered if VHF is suspected. The data may help decision makers to allocate resources and focus surveillance systems on the diseases of relevance in Ghana.

A phytosociological analysis and description of wetland vegetation and ecological factors associated with locations of high mortality for the 2010-11 Rift Valley fever outbreak in South Africa.

Science.gov (United States)

Brand, Robert F; Rostal, Melinda K; Kemp, Alan; Anyamba, Assaf; Zwiegers, Herman; Van Huyssteen, Cornelius W; Karesh, William B; Paweska, Janusz T

2018-01-01

Rift Valley fever (RVF) is endemic in Africa and parts of the Middle East. It is an emerging zoonotic disease threat to veterinary and public health. Outbreaks of the disease have severe socio-economic impacts. RVF virus emergence is closely associated with specific endorheic wetlands that are utilized by the virus' mosquito vectors. Limited botanical vegetation surveys had been published with regard to RVF virus (RVFV) ecology. We report on a phytosociological classification, analysis and description of wetland vegetation and related abiotic parameters to elucidate factors possibly associated with the 2010-2011 RVFV disease outbreak in South Africa. The study sites were located in the western Free State and adjacent Northern Cape covering an area of ~40,000 km2 with wetlands associated with high RVF mortality rates in livestock. Other study sites included areas where no RVF activity was reported during the 2010-11 RVF outbreak. A total of 129 plots (30 m2) were selected where a visible difference could be seen in the wetland and upland vegetation. The Braun-Blanquet method was used for plant sampling. Classification was done using modified Two-Way Indicator Species Analysis. The vegetation analysis resulted in the identification of eight plant communities, seven sub-communities and two variants. Indirect ordination was carried out using CANOCO to investigate the relationship between species and wetland ecology. The study also identified 5 categories of wetlands including anthropogenic wetlands. Locations of reported RVF cases overlapped sites characterized by high clay-content soils and specific wetland vegetation. These findings indicate ecological and environmental parameters that represent preferred breeding habitat for RVFV competent mosquito vectors.

Human and entomological surveillance of West Nile fever, dengue and chikungunya in Veneto Region, Italy, 2010-2012.

Science.gov (United States)

Gobbi, Federico; Capelli, Gioia; Angheben, Andrea; Giobbia, Mario; Conforto, Mario; Franzetti, Marzia; Cattelan, Anna Maria; Raise, Enzo; Rovere, Pierangelo; Mulatti, Paolo; Montarsi, Fabrizio; Drago, Andrea; Barzon, Luisa; Napoletano, Giuseppina; Zanella, Francesca; Pozza, Francesca; Russo, Francesca; Rosi, Paolo; Palù, Giorgio; Bisoffi, Zeno

2014-02-05

Since 2010 Veneto region (North-Eastern Italy) planned a special integrated surveillance of summer fevers to promptly identify cases of West Nile Fever (WNF), dengue (DENV) and chikungunya (CHIKV). The objectives of this study were (i) To increase the detection rate of imported CHIKV and DENV cases in travellers from endemic areas and promptly identify potential autochthonous cases.(ii) To detect autochthonous cases of WNF, besides those of West Nile Neuroinvasive Disease (WNND) that were already included in a national surveillance. Human surveillance: a traveler who had returned within the previous 15 days from endemic countries, with fever >38°C, absence of leucocytosis (leukocyte count 38°C for Entomologic surveillance: for West Nile (WNV) it was carried out from May through November placing CDC-CO2 traps in five provinces of Veneto Region, while for DENV and CHIKV it was also performed around residences of viremic cases. Human surveillance: between 2010 and 2012, 234 patients with fever after travelling were screened, of which 27 (11,5%) were found infected (24 with DENV and 3 with CHIKV). No autochthonous case of DENV or CHIKV was detected. Autochthonous patients screened for WNF were 408, and 24 (5,9%) were confirmed cases. Entomologic surveillance: the WNV was found in 10, 2 and 11 pools of Culex pipiens from 2010 to 2012 respectively, in sites of Rovigo, Verona, Venezia and Treviso provinces). No infected Aedes albopictus with DENV or CHIKV was found. Veneto is the only Italian region reporting WNV human cases every year since 2008. WNV is likely to cause sporadic cases and unforeseeable outbreaks for decades. Including WNF in surveillance provides additional information and possibly an early alert system. Timely detection of DENV and CHIKV should prompt vector control measures to prevent local outbreaks.

A landscape scale valley confinement algorithm: Delineating unconfined valley bottoms for geomorphic, aquatic, and riparian applications

Science.gov (United States)

David E. Nagel; John M. Buffington; Sharon L. Parkes; Seth Wenger; Jaime R. Goode

2014-01-01

Valley confinement is an important landscape characteristic linked to aquatic habitat, riparian diversity, and geomorphic processes. This report describes a GIS program called the Valley Confinement Algorithm (VCA), which identifies unconfined valleys in montane landscapes. The algorithm uses nationally available digital elevation models (DEMs) at 10-30 m resolution to...

Managing Rocky Mountain spotted fever.

Science.gov (United States)

Minniear, Timothy D; Buckingham, Steven C

2009-11-01

Rocky Mountain spotted fever is caused by the tick-borne bacterium Rickettsia rickettsii. Symptoms range from moderate illness to severe illness, including cardiovascular compromise, coma and death. The disease is prevalent in most of the USA, especially during warmer months. The trademark presentation is fever and rash with a history of tick bite, although tick exposure is unappreciated in over a third of cases. Other signature symptoms include headache and abdominal pain. The antibiotic therapy of choice for R. rickettsii infection is doxycycline. Preventive measures for Rocky Mountain spotted fever and other tick-borne diseases include: wearing long-sleeved, light colored clothing; checking for tick attachment and removing attached ticks promptly; applying topical insect repellent; and treating clothing with permethrin.

High-resolution three-dimensional imaging and analysis of rock falls in Yosemite valley, California

Science.gov (United States)

Stock, Gregory M.; Bawden, G.W.; Green, J.K.; Hanson, E.; Downing, G.; Collins, B.D.; Bond, S.; Leslar, M.

2011-01-01

We present quantitative analyses of recent large rock falls in Yosemite Valley, California, using integrated high-resolution imaging techniques. Rock falls commonly occur from the glacially sculpted granitic walls of Yosemite Valley, modifying this iconic landscape but also posing signifi cant potential hazards and risks. Two large rock falls occurred from the cliff beneath Glacier Point in eastern Yosemite Valley on 7 and 8 October 2008, causing minor injuries and damaging structures in a developed area. We used a combination of gigapixel photography, airborne laser scanning (ALS) data, and ground-based terrestrial laser scanning (TLS) data to characterize the rock-fall detachment surface and adjacent cliff area, quantify the rock-fall volume, evaluate the geologic structure that contributed to failure, and assess the likely failure mode. We merged the ALS and TLS data to resolve the complex, vertical to overhanging topography of the Glacier Point area in three dimensions, and integrated these data with gigapixel photographs to fully image the cliff face in high resolution. Three-dimensional analysis of repeat TLS data reveals that the cumulative failure consisted of a near-planar rock slab with a maximum length of 69.0 m, a mean thickness of 2.1 m, a detachment surface area of 2750 m2, and a volume of 5663 ?? 36 m3. Failure occurred along a surfaceparallel, vertically oriented sheeting joint in a clear example of granitic exfoliation. Stress concentration at crack tips likely propagated fractures through the partially attached slab, leading to failure. Our results demonstrate the utility of high-resolution imaging techniques for quantifying far-range (>1 km) rock falls occurring from the largely inaccessible, vertical rock faces of Yosemite Valley, and for providing highly accurate and precise data needed for rock-fall hazard assessment. ?? 2011 Geological Society of America.

78 FR 8960 - Texas (Splenetic) Fever in Cattle

Science.gov (United States)

2013-02-07

... microscopic parasites (Babesia) that cause bovine babesiosis. We are amending the list by clarifying that... cattle from areas of the United States that are quarantined because of ticks that are vectors for bovine... this section to indicate that the terms southern fever, cattle fever, Texas fever, bovine piroplasmosis...

Education Fever and Happiness in Korean Higher Education

Science.gov (United States)

Lee, Jeong-Kyu

2017-01-01

This article discusses relevance between education fever and happiness from the viewpoint of Korean higher education. To review this study systematically, three research questions are addressed. First, what is education fever from the viewpoint of the Korean people? Second, what are relations between education fever and happiness? Last, can…

THE MEANING OF FEVER IN CHILDREN

Directory of Open Access Journals (Sweden)

A. S. Polyakova

2015-01-01

Full Text Available Fever is a normal physiological response to illness in young children and it is often associated with a self-limiting viral infection. Fever is not a diagnosis, but a symptom of illness. A diagnosis of the underlying illness is essential to institute appropriate treatment. Although it is a normal response, that facilitates and accelerates recovery, some people, including many doctors, believe that fever should be treated to reduce temperature without determining the underlying illness causing the fever. Antipyretics should be used to make the child more comfortable and not used routinely with the sole aim of reducing the temperature. This article aims to acquaint primary healthcare workers and general practitioners with last guidelines to assist the measurement of body temperature, deciding on when to refer and the appropriate use of antipyretic medication in children, efficacy and safety of paracetamol and ibuprofen in oral and rectal forms. 

Small martian valleys: Pristine and degraded morphology

International Nuclear Information System (INIS)

Baker, V.R.; Partridge, J.B.

1986-01-01

The equatorial heavily cratered uplands of Mars are dissected by two classes of small valleys that are intimately associated in compound networks. Pristine valleys with steep valley walls preferentially occupy downstream portions of compound basins. Degraded valleys with eroded walls are laterally more extensive and have higher drainage densities than pristine valleys. Morphometric and crater-counting studies indicate that relatively dense drainage networks were emplaced on Mars during the heavy bombardment about 4.0 b.y. ago. Over a period of approximately 10 8 years, these networks were degraded and subsequently invaded by headwardly extending pristine valleys. The pristine valleys locally reactivated the compound networks, probably through sapping processes dependent upon high water tables. Fluvial activity in the heavily cratered uplands generally ceased approximately 3.8--3.9 b.y. ago, coincident with the rapid decline in cratering rates. The relict compound valleys on Mars are morphometrically distinct from most terrestrial drainage systems. The differences might be caused by a Martian valley formation episode characterized by hyperaridity, by inadequate time for network growth, by very permeable rock types, or by a combination of factors

Scarlet Fever

Centers for Disease Control (CDC) Podcasts

2011-06-09

Katherine Fleming-Dutra, pediatrician, discusses scarlet fever, its cause, how to treat it, and how to prevent its spread.  Created: 6/9/2011 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 6/9/2011.

Why is African swine fever still present in Sardinia?

Science.gov (United States)

Jurado, C; Fernández-Carrión, E; Mur, L; Rolesu, S; Laddomada, A; Sánchez-Vizcaíno, J M

2018-04-01

African swine fever (ASF) is an infectious disease of swine that has been present in Sardinia since 1978. Soon after introduction of the disease, several control and eradication programmes were established with limited success. Some researchers attributed the persistence of the disease in central and eastern areas to certain socio-economic factors, the existence of some local and traditional farming practices (i.e., unregistered free-ranging pigs known as brado animals) and the high density of wild boar in the region. In the past, scarcity of swine data in Sardinia complicated the evaluation and study of ASF on the island. More complete, accurate and reliable information on pig farms has become available as a result of the most recent eradication programmes. Here, we perform statistical modelling based on these data and the known distribution of domestic pig and wild boar to identify the main risk factors that have caused ASF persistence in Sardinia. Our results categorized, identified and quantified nine significant risk factors, six of which have not been previously described. The most significant factors were the number of medium-sized farms, the presence of brado animals and the combination of estimated wild boar density and mean altitude above sea level. Based on these factors, we identified regions in eastern and central Sardinia to be at greatest risk of ASF persistence; these regions are also where the disease has traditionally been endemic. Based on these risk factors, we propose specific control measures aimed at mitigating such risks and eradicating ASF from the island. © 2017 Blackwell Verlag GmbH.

Geologic summary of the Owens Valley drilling project, Owens and Rose Valleys, Inyo County, California

International Nuclear Information System (INIS)

Schaer, D.W.

1981-07-01

The Owens Valley Drilling Project consists of eight drill holes located in southwest Inyo County, California, having an aggregate depth of 19,205 feet (5853 m). Project holes penetrated the Coso Formation of upper Pliocene or early Pleistocene age and the Owens Lake sand and lakebed units of the same age. The project objective was to improve the reliability of uranium-potential-resource estimates assigned to the Coso Formation in the Owens Valley region. Uranium-potential-resource estimates for this area in $100 per pound U 3 O 8 forward-cost-category material have been estimatd to be 16,954 tons (15,384 metric tons). This estimate is based partly on project drilling results. Within the Owens Valley project area, the Coso Formation was encountered only in the Rose Valley region, and for this reason Rose Valley is considered to be the only portion of the project area favorable for economically sized uranium deposits. The sequence of sediments contained in the Owens Valley basin is considered to be largely equivalent but lithologically dissimilar to the Coso Formation of Haiwee Ridge and Rose Valley. The most important factor in the concentration of significant amounts of uranium in the rock units investigated appears to be the availability of reducing agents. Significant amounts of reductants (pyrite) were found in the Coso Formation. No organic debris was noted. Many small, disconnected uranium occurrences, 100 to 500 ppM U 3 O 8 , were encountered in several of the holes

Depth to water in the western Snake River Plain and surrounding tributary valleys, southwestern Idaho and eastern Oregon, calculated using water levels from 1980 to 1988

Science.gov (United States)

Maupin, Molly A.

1991-01-01

The vulnerability of ground water to contamination in Idaho is being assessed by the ISHW/DEQ (Idaho Department of Health and Welfare, Division of Environmental Quality), using a modified version of the Environmental Protection Agency DRASTIC methods (Allers and others, 1985). The project was designed as a technique to: (1) Assign priorities for development of ground-water management and monitoring programs; (2) build support for, and public awareness of, vulnerability of ground water to contamination; (3) assist in the development of regulatory programs; and (4) provide access to technical data through the use of a GIS (geographic information system) (C. Grantham, Idaho Department of Health and Welfare, written commun., 1989). Digital representation of first-encountered water below land surface is an important element in evaluating vulnerability of ground water to contamination. Depth-to-water values were developed using existing data and computer software to construct a GIS data set to be combined with a soils data set developed by the SCS (Soul Conservation Service) and the IDHW/WQB (Idaho Department of Health and Welfare/Water Quality Bureau), and a recharge data set developed by the IDWR/RSF (idaho Department of Water Resources/Remote Sensing Facility). The USGS (U.S. Geological Survey) has developed digital depth-to-water values for eleven 1:100,00-scale quadrangles on the eastern Snake River Plain and surrounding tributary valleys.

Valley dependent transport in graphene L junction

Science.gov (United States)

Chan, K. S.

2018-05-01

We studied the valley dependent transport in graphene L junctions connecting an armchair lead and a zigzag lead. The junction can be used in valleytronic devices and circuits. Electrons injected from the armchair lead into the junction is not valley polarized, but they can become valley polarized in the zigzag lead. There are Fermi energies, where the current in the zigzag lead is highly valley polarized and the junction is an efficient generator of valley polarized current. The features of the valley polarized current depend sensitively on the widths of the two leads, as well as the number of dimers in the armchair lead, because this number has a sensitive effect on the band structure of the armchair lead. When an external potential is applied to the junction, the energy range with high valley polarization is enlarged enhancing its function as a generator of highly valley polarized current. The scaling behavior found in other graphene devices is also found in L junctions, which means that the results presented here can be extended to junctions with larger dimensions after appropriate scaling of the energy.

Early fever after trauma: Does it matter?

Science.gov (United States)

Hinson, Holly E; Rowell, Susan; Morris, Cynthia; Lin, Amber L; Schreiber, Martin A

2018-01-01

Fever is strongly associated with poor outcome after traumatic brain injury (TBI). We hypothesized that early fever is a direct result of brain injury and thus would be more common in TBI than in patients without brain injury and associated with inflammation. We prospectively enrolled patients with major trauma with and without TBI from a busy Level I trauma center intensive care unit (ICU). Patients were assigned to one of four groups based on their presenting Head Abbreviated Injury Severity Scale scores: multiple injuries: head Abbreviated Injury Scale (AIS) score greater than 2, one other region greater than 2; isolated head: head AIS score greater than 2, all other regions less than 3; isolated body: one region greater than 2, excluding head/face; minor injury: no region with AIS greater than 2. Early fever was defined as at least one recorded temperature greater than 38.3°C in the first 48 hours after admission. Outcome measures included neurologic deterioration, length of stay in the ICU, hospital mortality, discharge Glasgow Outcome Scale-Extended, and plasma levels of seven key cytokines at admission and 24 hours (exploratory). Two hundred sixty-eight patients were enrolled, including subjects with multiple injuries (n = 59), isolated head (n = 97), isolated body (n = 100), and minor trauma (n = 12). The incidence of fever was similar in all groups irrespective of injury (11-24%). In all groups, there was a significant association between the presence of early fever and death in the hospital (6-18% vs. 0-3%), as well as longer median ICU stays (3-7 days vs. 2-3 days). Fever was significantly associated with elevated IL-6 at admission (50.7 pg/dL vs. 16.9 pg/dL, p = 0.0067) and at 24 hours (83.1 pg/dL vs. 17.1 pg/dL, p = 0.0025) in the isolated head injury group. Contrary to our hypothesis, early fever was not more common in patients with brain injury, though fever was associated with longer ICU stays and death in all groups. Additionally, fever was

Hemodynamic and oxygenation changes in surgical intensive care unit patients with fever and fever lowering nursing interventions.

Science.gov (United States)

Çelik, Sevim; Yildirim, Ismail; Arslan, Ibrahim; Yildirim, Sinan; Erdal, Fatih; Yandi, Yunus Emre

2011-12-01

The purpose of this study was to determine the effects of fever and nursing interventions to lower fever on hemodynamic values and oxygenation in febrile (temperature greater than 38.3°C) surgical intensive care unit patients. This retrospective study was conducted in 53 febrile patients out of 519 patients admitted to the surgical intensive care unit at a university hospital. Data were obtained from the medical records, laboratory files and nursing notes. Statistical analysis of the data was analyzed by repeated measures analysis of variance and a paired sample t-test. The average hourly urine output (F = 5.46; P = 0.002) and systolic blood pressure (F = 2.87; P = 0.03) were significantly lower after fever onset. Heart rate, respiratory rate, positive end-expiratory pressure settings and FiO(2) settings were unchanged after the development of fever. Diastolic blood pressure and oxygen saturation had non-statistically significant decreases. Nursing interventions for febrile patients consisted of medication administration (69.8%), ice (62.3%) and sponging with tepid water (62.3%). The present results showed that fever was associated with an increase in heart rate, decreased systolic arterial pressure, mean arterial pressure, oxygen saturation and hourly urine output. © 2011 Blackwell Publishing Asia Pty Ltd.

Diagnostic value of FDG-PET/(CT) in children with fever of unknown origin and unexplained fever during immune suppression

Energy Technology Data Exchange (ETDEWEB)

Blokhuis, Gijsbert J.; Diender, Marije G.; Oyen, Wim J.G. [Radboud University Medical Center, Department of Nuclear Medicine, Nijmegen (Netherlands); Bleeker-Rovers, Chantal P. [Radboud University Medical Center, Division of Infectious Diseases, Department of Internal Medicine, Nijmegen (Netherlands); Draaisma, Jos M.T. [Radboud University Medical Center, Department of Paediatrics, Nijmegen (Netherlands); Geus-Oei, Lioe-Fee de [Radboud University Medical Center, Department of Nuclear Medicine, Nijmegen (Netherlands); University of Twente, MIRA Institute for Biomedical Technology and Technical Medicine, Biomedical Photonic Imaging Group, Enschede (Netherlands)

2014-10-15

Fever of unknown origin (FUO) and unexplained fever during immune suppression in children are challenging medical problems. The aim of this study is to investigate the diagnostic value of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and FDG-PET combined with computed tomography (FDG-PET/CT) in children with FUO and in children with unexplained fever during immune suppression. All FDG-PET/(CT) scans performed in the Radboud university medical center for the evaluation of FUO or unexplained fever during immune suppression in the last 10 years were reviewed. Results were compared with the final clinical diagnosis. FDG-PET/(CT) scans were performed in 31 children with FUO. A final diagnosis was established in 16 cases (52 %). Of the total number of scans, 32 % were clinically helpful. The sensitivity and specificity of FDG-PET/CT in these patients was 80 % and 78 %, respectively. FDG-PET/(CT) scans were performed in 12 children with unexplained fever during immune suppression. A final diagnosis was established in nine patients (75 %). Of the total number of these scans, 58 % were clinically helpful. The sensitivity and specificity of FDG-PET/CT in children with unexplained fever during immune suppression was 78 % and 67 %, respectively. FDG-PET/CT appears a valuable imaging technique in the evaluation of children with FUO and in the diagnostic process of children with unexplained fever during immune suppression. Prospective studies of FDG-PET/CT as part of a structured diagnostic protocol are warranted to assess the additional diagnostic value. (orig.)

Diagnostic value of FDG-PET/(CT) in children with fever of unknown origin and unexplained fever during immune suppression

International Nuclear Information System (INIS)

Blokhuis, Gijsbert J.; Diender, Marije G.; Oyen, Wim J.G.; Bleeker-Rovers, Chantal P.; Draaisma, Jos M.T.; Geus-Oei, Lioe-Fee de

2014-01-01

Fever of unknown origin (FUO) and unexplained fever during immune suppression in children are challenging medical problems. The aim of this study is to investigate the diagnostic value of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and FDG-PET combined with computed tomography (FDG-PET/CT) in children with FUO and in children with unexplained fever during immune suppression. All FDG-PET/(CT) scans performed in the Radboud university medical center for the evaluation of FUO or unexplained fever during immune suppression in the last 10 years were reviewed. Results were compared with the final clinical diagnosis. FDG-PET/(CT) scans were performed in 31 children with FUO. A final diagnosis was established in 16 cases (52 %). Of the total number of scans, 32 % were clinically helpful. The sensitivity and specificity of FDG-PET/CT in these patients was 80 % and 78 %, respectively. FDG-PET/(CT) scans were performed in 12 children with unexplained fever during immune suppression. A final diagnosis was established in nine patients (75 %). Of the total number of these scans, 58 % were clinically helpful. The sensitivity and specificity of FDG-PET/CT in children with unexplained fever during immune suppression was 78 % and 67 %, respectively. FDG-PET/CT appears a valuable imaging technique in the evaluation of children with FUO and in the diagnostic process of children with unexplained fever during immune suppression. Prospective studies of FDG-PET/CT as part of a structured diagnostic protocol are warranted to assess the additional diagnostic value. (orig.)

Rat bite fever in a pet lover.

Science.gov (United States)

Cunningham, B B; Paller, A S; Katz, B Z

1998-02-01

Rat-bite fever is an uncommon bacterial illness resulting from infection with Streptobacillus moniliformis that is often transmitted by the bite of a rat. The cutaneous findings in rat-bite fever are nonspecific but have been described as maculopapular or petechial. We describe a 9-year-old girl with acrally distributed hemorrhagic pustules, fever, and arthralgias. Diagnosis was delayed because of difficulty in identifying the pathologic organism. She was successfully treated with 10 days of ceftriaxone.

Identification of a new genotype of African swine fever Virus in domestic pigs from Ethiopia

International Nuclear Information System (INIS)

Achenbach, J.E.; Gallardo, C.; Nieto-Pelegrín, E.; Rivera-Arroyo, B.; Degefa-Negi, T.; Arias, M.; Jenberie, S.; Mulisa, D.D.; Gizaw, D.; Gelaye, E.; Chibssa, T.R.; Belaye, A.; Loitsch, A.; Forsa, M.; Yami, M.; Diallo, A.; Soler, A.; Lamien, C.E.

2016-01-01

Full text: African swine fever (ASF) is an important emerging transboundary animal disease (TAD), which currently has an impact on many countries in Africa, Eastern Europe, the Caucasus and the Russian Federation. The current situation in Europe shows the ability of the virus to rapidly spread, which stands to threaten the global swine industry. At present, there is no viable vaccine to minimize spread of the disease and stamping out is the main source of control. In February 2011, Ethiopia had reported its first suspected outbreaks of ASF. Genomic analyses of the collected ASF virus (ASFV) strains were undertaken using 23 tissue samples collected from domestic swine in Ethiopia from 2011 to 2014. The analysis of Ethiopian ASFVs partial p72 gene sequence showed the identification of a new genotype, genotype XXIII that shares a common ancestor with genotypes IX and X, which comprise isolates circulating in Eastern African countries and the Republic of Congo. Analysis of the p54 gene also followed the p72 pattern and the deduced amino acid sequence of the central variable region (CVR) of the B602L gene showed novel tetramer repeats not previously characterized. (author)

New Constraints on Late Pleistocene - Holocene Slip Rates and Seismic Behavior Along the Panamint Valley Fault Zone, Eastern California

Science.gov (United States)

Hoffman, W.; Kirby, E.; McDonald, E.; Walker, J.; Gosse, J.

2008-12-01

Space-time patterns of seismic strain release along active fault systems can provide insight into the geodynamics of deforming lithosphere. Along the eastern California shear zone, fault systems south of the Garlock fault appear to have experienced an ongoing pulse of seismic activity over the past ca. 1 kyr (Rockwell et al., 2000). Recently, this cluster of seismicity has been implicated as both cause and consequence of the oft-cited discrepancy between geodetic velocities and geologic slip rates in this region (Dolan et al., 2007; Oskin et al., 2008). Whether other faults within the shear zone exhibit similar behavior remains uncertain. Here we report the preliminary results of new investigations of slip rates and seismic history along the Panamint Valley fault zone (PVFZ). The PVFZ is characterized by dextral, oblique-normal displacement along a moderately to shallowly-dipping range front fault. Previous workers (Zhang et al., 1990) identified a relatively recent surface rupture confined to a ~25 km segment of the southern fault zone and associated with dextral displacements of ~3 m. Our mapping reveals that youthful scarps ranging from 2-4 m in height are distributed along the central portion of the fault zone for at least 50 km. North of Ballarat, a releasing jog in the fault zone forms a 2-3 km long embayment. Displacement of debris-flow levees and channels along NE-striking faults that confirm that displacement is nearly dip-slip, consistent with an overall transport direction toward ~340°, and affording an opportunity to constrain fault displacement directly from the vertical offset of alluvial surfaces of varying age. At the mouth of Happy Canyon, the frontal fault strand displaces a fresh debris-flow by ~3-4 m; soil development atop the debris-flow surface is incipient to negligible. Radiocarbon ages from logs embedded in the flow matrix constrain the timing of the most recent event to younger than ~ 600 cal yr BP. Older alluvial surfaces, such as that

High content image-based screening of a protease inhibitor library reveals compounds broadly active against Rift Valley fever virus and other highly pathogenic RNA viruses.

Directory of Open Access Journals (Sweden)

Rajini Mudhasani

2014-08-01

Full Text Available High content image-based screening was developed as an approach to test a protease inhibitor small molecule library for antiviral activity against Rift Valley fever virus (RVFV and to determine their mechanism of action. RVFV is the causative agent of severe disease of humans and animals throughout Africa and the Arabian Peninsula. Of the 849 compounds screened, 34 compounds exhibited ≥ 50% inhibition against RVFV. All of the hit compounds could be classified into 4 distinct groups based on their unique chemical backbone. Some of the compounds also showed broad antiviral activity against several highly pathogenic RNA viruses including Ebola, Marburg, Venezuela equine encephalitis, and Lassa viruses. Four hit compounds (C795-0925, D011-2120, F694-1532 and G202-0362, which were most active against RVFV and showed broad-spectrum antiviral activity, were selected for further evaluation for their cytotoxicity, dose response profile, and mode of action using classical virological methods and high-content imaging analysis. Time-of-addition assays in RVFV infections suggested that D011-2120 and G202-0362 targeted virus egress, while C795-0925 and F694-1532 inhibited virus replication. We showed that D011-2120 exhibited its antiviral effects by blocking microtubule polymerization, thereby disrupting the Golgi complex and inhibiting viral trafficking to the plasma membrane during virus egress. While G202-0362 also affected virus egress, it appears to do so by a different mechanism, namely by blocking virus budding from the trans Golgi. F694-1532 inhibited viral replication, but also appeared to inhibit overall cellular gene expression. However, G202-0362 and C795-0925 did not alter any of the morphological features that we examined and thus may prove to be good candidates for antiviral drug development. Overall this work demonstrates that high-content image analysis can be used to screen chemical libraries for new antivirals and to determine their

Investigation of hemorrhagic fever viruses inside wild populations of ticks: One of the pioneer studies in Saudi Arabia

Directory of Open Access Journals (Sweden)

Rania Ali El Hadi Mohamed

2017-05-01

Full Text Available Objective: To screen hemorrhagic fever viruses inside wild populations of ticks collected from Riyadh, Saudi Arabia between January and March 2016. Methods: Ticks were identified depending on their morphological features using classical keys then grouped into pools. Ticks in each pool were processed separately using the sterile pestles and mortars. Viral RNA was extracted using Qiagen RNeasy Mini Kit and Qiagen RNAeasy Columns (Qiagen, Hilden, Germany according to the instructions of manufacturers. A total number of 1 282 hard ticks were collected, and 582 of them were precisely identified then screened for the presence of arboviruses using quantitative real-time PCR. The four species were screened for six viruses: Rift Valley fever virus (RVFV, Chikungunya virus (CHIKV, Crimean-Congo hemorrhagic fever virus (CCHFV, Alkhurma virus (INKV, Sindbis virus (SINV, and Pan Hanta virus (HANTA. CT value for the negative control (RNA free water was zero. Negative and positive controls were tested for each test to confirm the specificity of the selected primer pairs. SYBR Green One step RT-PCR Master Mix (KAPA Biosystems, Boston, MA was tested along with primers. Results: Ticks identification resulted into four species: Hyalomma schulzei, Hyalomma onatoli, Boophilus kdhlsi, and Hyalomm dromedarii. All the ticks’ species (except Boophilus kdhlsi were positive for the following viruses: SINV, RVFV, CHIKV, and CCHFV. While HANTA viruses have been detected in a single species (Hyalomm dromedarii. Conclusions: According to our knowledge this research may be one of the pioneer studies in Kingdom of Saudi Arabia. Incrimination of the above mentioned ticks species as well as their vectorial capacity are highly recommended for investigation in the upcoming researches.

Seismic-refraction survey to the top of salt in the north end of the Salt Valley Anticline, Grand County, Utah

Science.gov (United States)

Ackermann, Hans D.

1979-01-01

A seismic-refraction survey, consisting of three lines about 2700, 2760, and 5460 meters long, was made at the north end of the Salt Valley anticline of the Paradox Basin in eastern Utah. The target was the crest of a diapiric salt mass and the overlying, deformed caprock. The interpretations reveal an undulating salt surface with as much as 80 meters of relief. The minimum depth of about 165 meters is near the location of three holes drilled by the U.S. Department of Energy for the purpose of evaluating the Salt Valley anticline as a potential site for radioactive waste storages Caprock properties were difficult to estimate because the contorted nature of these beds invalidated a geologic interpretation in terms of velocity layers. However, laterally varying velocities of the critically refracted rays throughout the area suggest differences in the gross physical properties of the caprock.

Seismic-refraction survey to the top of salt in the north end of the Salt valley anticline, Grand County, Utah

International Nuclear Information System (INIS)

Achermann, H.D.

1979-01-01

A sesimic-refraction survey, consisting of three lines about 2700, 2760, and 5460 meters long, was made at the north end of the Salt valley anticline of the Paradox Basin in eastern Utah. The target was the crest of a diapiric salt mass and the overlying, deformed caprock. The interpretations reveal an undulating salt surface with as much as 80 meters of relief. The minimum depth of about 165 meters is near the location of three holes drilled by the US Department of Energy for the purpose of evaluating the Salt Valley anticline as a potential site for radioactive waste storage. Caprock properties were difficult to estimate because the contorted nature of these beds invalidated a goelogic interpretation in terms of velocity layers. However, laterally varying velocities of the critically refracted rays throughout the area suggest differences in the gross physical properties of the caprock

Dengue hemorrhagic fever and acute hepatitis: a case report

Directory of Open Access Journals (Sweden)

Maria Paula Gomes Mourão

Full Text Available Dengue fever is the world's most important viral hemorrhagic fever disease, the most geographically wide-spread of the arthropod-born viruses, and it causes a wide clinical spectrum of disease. We report a case of dengue hemorrhagic fever complicated by acute hepatitis. The initial picture of classical dengue fever was followed by painful liver enlargement, vomiting, hematemesis, epistaxis and diarrhea. Severe liver injury was detected by laboratory investigation, according to a syndromic surveillance protocol, expressed in a self-limiting pattern and the patient had a complete recovery. The serological tests for hepatitis and yellow fever viruses were negative. MAC-ELISA for dengue was positive.

Dengue hemorrhagic fever and acute hepatitis: a case report.

Science.gov (United States)

Mourão, Maria Paula Gomes; Lacerda, Marcus Vinícius Guimarães de; Bastos, Michele de Souza; Albuquerque, Bernardino Cláudio de; Alecrim, Wilson Duarte

2004-12-01

Dengue fever is the world's most important viral hemorrhagic fever disease, the most geographically wide-spread of the arthropod-born viruses, and it causes a wide clinical spectrum of disease. We report a case of dengue hemorrhagic fever complicated by acute hepatitis. The initial picture of classical dengue fever was followed by painful liver enlargement, vomiting, hematemesis, epistaxis and diarrhea. Severe liver injury was detected by laboratory investigation, according to a syndromic surveillance protocol, expressed in a self-limiting pattern and the patient had a complete recovery. The serological tests for hepatitis and yellow fever viruses were negative. MAC-ELISA for dengue was positive.

Dengue fever with rectus sheath hematoma: A case report

Directory of Open Access Journals (Sweden)

Anurag Sharma

2014-01-01

Full Text Available Dengue fever, also known as breakbone fever, is an infectious tropical disease caused by the Dengue virus. It is associated with a number of complications, which are well documented. However, Dengue fever associated with rectus sheath hematoma (RSH is a very rare complication. Only one case report has been published prior supporting the association of Dengue fever with RSH. We report a case of Dengue fever who presented with RSH and was successfully treated conservatively. RSH is also an uncommon cause of acute abdominal pain. It is accumulation of blood in the sheath of the rectus abdominis, secondary to rupture of an epigastric vessel or muscle tear.

Studies on the pathogenesis of fever. VIII. Further observations on the role of endogenous pyrogen in endotoxin fever.

Science.gov (United States)

GILLMAN, S M; BORNSTEIN, D L; WOOD, W B

1961-11-01

Rabbits made granulocytopenic with nitrogen mustard have been shown to generate serum endogenous pyrogen when given a fever-producing dose of bacterial endotoxin. This finding is in accord with the hypothesis that endogenous pyrogen plays a central role in the pathogenesis of endotoxin fever. The fact that leucopenic animals produce less serum-endogenous pyrogen than normal animals given the same dose of endotoxin has also been confirmed and suggests that polymorphonuclear leucocytes constitute a major source of the endogenous pyrogen which is demonstrable in the circulation during endotoxin fever.

Analyzing tree cores to detect petroleum hydrocarbon-contaminated groundwater at a former landfill site in the community of Happy Valley-Goose Bay, eastern Canadian subarctic.

Science.gov (United States)

Fonkwe, Merline L D; Trapp, Stefan

2016-08-01

This research examines the feasibility of analyzing tree cores to detect benzene, toluene, ethylbenzene, and m, p, o-xylene (BTEX) compounds and methyl tertiary-butyl ether (MTBE) in groundwater in eastern Canada subarctic environments, using a former landfill site in the remote community of Happy Valley-Goose Bay, Labrador. Petroleum hydrocarbon contamination at the landfill site is the result of environmentally unsound pre-1990s disposal of households and industrial solid wastes. Tree cores were taken from trembling aspen, black spruce, and white birch and analyzed by headspace-gas chromatography-mass spectrometry. BTEX compounds were detected in tree cores, corroborating known groundwater contamination. A zone of anomalously high concentrations of total BTEX constituents was identified and recommended for monitoring by groundwater wells. Tree cores collected outside the landfill site at a local control area suggest the migration of contaminants off-site. Tree species exhibit different concentrations of BTEX constituents, indicating selective uptake and accumulation. Toluene in wood exhibited the highest concentrations, which may also be due to endogenous production. Meanwhile, MTBE was not found in the tree cores and is considered to be absent in the groundwater. The results demonstrate that tree-core analysis can be useful for detecting anomalous concentrations of petroleum hydrocarbons, such as BTEX compounds, in subarctic sites with shallow unconfined aquifers and permeable soils. This method can therefore aid in the proper management of contamination during landfill operations and after site closures.

Mackenzie Valley Pipeline market demand, supply, and infrastructure analysis : final report

International Nuclear Information System (INIS)

2004-01-01

Mackenzie Valley Pipeline Co-Venturers is a consortium of petroleum companies proposing to construct a 1,400 km long, large-diameter, high-pressure natural gas transmission pipeline from the northwestern edge of the Northwest Territories to the Alberta-Northwest Territories border. The Mackenzie Valley Pipeline will bring natural gas from the Mackenzie Delta region to markets in Alberta, central and eastern Canada and the United States. Navigant Consulting Ltd. prepared this assessment of the long-term market need for natural gas produced from the Mackenzie Delta. It presents an analysis of gas demand, supply and infrastructure. Three sensitivity cases were examined, incorporating different assumptions about the initial capacity of the pipeline, potential expansion of its capacity and different levels of gas demand in Canada and the United States. The report indicates that gas markets in North America support construction of the proposed 34 million cubic metre per day pipeline in the 2009 timeframe, with possible expansion in 2015 and 2020. It also indicates that there will be enough capacity on the intra-Alberta gas transmission system to accommodate the projected deliveries of Mackenzie Delta gas. The increase in gas demand is due to an increase in residential and commercial gas consumption, electric power generation and the energy intensive bitumen extraction and processing activities in the Alberta oil sands industry. 36 tabs., 56 figs

CLINICAL AND LABORATORY PROFILE OF DENGUE FEVER