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Sample records for acute dengue virus

  1. Acute kidney injury in dengue virus infection

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    Khalil, Muhammad A.M.; Sarwar, Sarfaraz; Chaudry, Muhammad A.; Maqbool, Baila; Khalil, Zarghoona; Tan, Jackson; Yaqub, Sonia; Hussain, Syed A.

    2012-01-01

    Background Dengue is a growing public health problem in Pakistan and acute kidney injury (AKI) is one of the least studied complications of dengue virus infection (DVI). The aim of this study was to determine the frequency, severity and predictors of AKI in patients with DVI and to study the impact of AKI on the length of hospital stay and mortality. Methods We retrospectively reviewed medical records of patients aged ≥14 years hospitalized with a primary diagnosis of DVI at Aga Khan University Hospital Karachi between January 2008 and December 2010. Binary logistic regression models were constructed to identify factors associated with the development of AKI and to study the impact of AKI on hospital stays of more than 3 days. Results Out of 532 patients, AKI was present in 13.3% (71/532). Approximately two-thirds (64.8%) of these patients had mild AKI and a third (35.2%) had moderate to severe AKI. Independent predictors for AKI were male gender [odds ratio (OD) 4.43; 95% CI 1.92–10.23], presence of dengue hemorrhagic and dengue shock syndrome (DSS, OD 2.14; 95% CI 1.06–4.32), neurological involvement (OD 12.08; 95% CI 2.82–51.77) and prolonged activated partial thromboplastin time (aPTT, OD 1.81; 95% CI 1.003–3.26). AKI was associated with a length of stay ≥3 days when compared with those who did not have AKI (OD 2.98; 95% CI 1.66–5.34). Eight patients (11.3%) with AKI died whereas there were no mortalities in patients without AKI (P < 0.001). Only 5 patients (7%) had persistent kidney dysfunction at discharge. Conclusions AKI in DVI is associated with neurological involvement, prolongation of aPTT, greater length of hospital stay and increased mortality. PMID:26019813

  2. Acute hepatitis due to dengue virus in a chronic hepatitis patient

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    Souza, L J; Coelho, J.M.C. de O.; Silva,E. J.; Abukater,M.; Almeida,F.C.R.; A. S. Fonte; L.A Souza

    2008-01-01

    We present a case of acute hepatitis caused by dengue virus, with a significant increase in aspartate transferase and alanine transferase levels in a chronic hepatitis patient attended at the Cane Sugar Planters Hospital of Campos dos Goytacazes, RJ.

  3. Quasispecies of dengue virus.

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    Kurosu, Takeshi

    2011-12-01

    Pathogenic viruses have RNA genomes that cause acute and chronic infections. These viruses replicate with high mutation rates and exhibit significant genetic diversity, so-called viral quasispecies. Viral quasispecies play an important role in chronic infectious diseases, but little is known about their involvement in acute infectious diseases such as dengue virus (DENV) infection. DENV, the most important human arbovirus, is a causative agent of dengue fever (DF) and dengue hemorrhagic fever (DHF). Accumulating observations suggest that DENV exists as an extremely diverse virus population, but its biological significance is unclear. In other virus diseases, quasispecies affect the therapeutic strategies using drugs and vaccines. Here, I describe the quasispecies of DENV and discuss the possible role of quasispecies in the pathogenesis of and therapeutic strategy against DENV infection in comparison with other viruses such as Hepatitis C virus, human immunodeficiency virus type 1, and poliovirus.

  4. Acute Febrile Illness Surveillance in a Tertiary Hospital Emergency Department: Comparison of Influenza and Dengue Virus Infections

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    Lorenzi, Olga D.; Gregory, Christopher J.; Santiago, Luis Manuel; Acosta, Héctor; Galarza, Ivonne E.; Hunsperger, Elizabeth; Muñoz, Jorge; Bui, Duy M.; Oberste, M. Steven; Peñaranda, Silvia; García-Gubern, Carlos; Tomashek, Kay M.

    2013-01-01

    In 2009, an increased proportion of suspected dengue cases reported to the surveillance system in Puerto Rico were laboratory negative. As a result, enhanced acute febrile illness (AFI) surveillance was initiated in a tertiary care hospital. Patients with fever of unknown origin for 2–7 days duration were tested for Leptospira, enteroviruses, influenza, and dengue virus. Among the 284 enrolled patients, 31 dengue, 136 influenza, and 3 enterovirus cases were confirmed. Nearly half (48%) of the confirmed dengue cases met clinical criteria for influenza. Dengue patients were more likely than influenza patients to have hemorrhage (81% versus 26%), rash (39% versus 9%), and a positive tourniquet test (52% versus 18%). Mean platelet and white blood cell count were lower among dengue patients. Clinical diagnosis can be particularly difficult when outbreaks of other AFI occur during dengue season. A complete blood count and tourniquet test may be useful to differentiate dengue from other AFIs. PMID:23382160

  5. False positive dengue NS1 antigen test in a traveller with an acute Zika virus infection imported into Switzerland.

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    Gyurech, Danielle; Schilling, Julian; Schmidt-Chanasit, Jonas; Cassinotti, Pascal; Kaeppeli, Franz; Dobec, Marinko

    2016-01-01

    We report the first case of an acute Zika virus infection imported into Switzerland by a traveller returning from Canoa Quebrada, Ceará state, in the north-eastern part of Brazil. Due to a false positive dengue virus NS1 antigen test, IgG antibody seroconversion and a suggestive clinical picture,an acute dengue fever was initially considered. However, because of lack of specific IgM-antibodies, stationary IgG antibody titre and a negative dengue virus PCR test result, a dengue virus infection was excluded and a cross-reaction with other, causative flaviviruses was postulated. Based on recent reports of Zika fever cases in the north-eastern parts of Brazil, an acute Zika virus infection was suspected. Because of a lack of commercially available Zika virus diagnostic tests, the case was confirmed in the WHO reference laboratory. As the clinical presentation of Zika virus infection can be confused with dengue fever and chikungunya fever, and because of possible public health implications, all patients returning from affected areas should be additionally tested for Zika virus. This case illustrates the urgent medical need for a broadly available assay capable of differentiating Zika from Dengue infections.

  6. Dynamics of cellular immune responses in the acute phase of dengue virus infection.

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    Yoshida, Tomoyuki; Omatsu, Tsutomu; Saito, Akatsuki; Katakai, Yuko; Iwasaki, Yuki; Kurosawa, Terue; Hamano, Masataka; Higashino, Atsunori; Nakamura, Shinichiro; Takasaki, Tomohiko; Yasutomi, Yasuhiro; Kurane, Ichiro; Akari, Hirofumi

    2013-06-01

    In this study, we examined the dynamics of cellular immune responses in the acute phase of dengue virus (DENV) infection in a marmoset model. Here, we found that DENV infection in marmosets greatly induced responses of CD4/CD8 central memory T and NKT cells. Interestingly, the strength of the immune response was greater in animals infected with a dengue fever strain than in those infected with a dengue hemorrhagic fever strain of DENV. In contrast, when animals were re-challenged with the same DENV strain used for primary infection, the neutralizing antibody induced appeared to play a critical role in sterilizing inhibition against viral replication, resulting in strong but delayed responses of CD4/CD8 central memory T and NKT cells. The results in this study may help to better understand the dynamics of cellular and humoral immune responses in the control of DENV infection.

  7. Elevated levels of cell-free circulating DNA in patients with acute dengue virus infection.

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    Tran Thi Ngoc Ha

    Full Text Available BACKGROUND: Apoptosis is thought to play a role in the pathogenesis of severe dengue and the release of cell-free DNA into the circulatory system in several medical conditions. Therefore, we investigated circulating DNA as a potential biomarker for severe dengue. METHODS AND FINDINGS: A direct fluorometric degradation assay using PicoGreen was performed to quantify cell-free DNA from patient plasma. Circulating DNA levels were significantly higher in patients with dengue virus infection than with other febrile illnesses and healthy controls. Remarkably, the increase of DNA levels correlated with the severity of dengue. Additionally, multivariate logistic regression analysis showed that circulating DNA levels independently correlated with dengue shock syndrome. CONCLUSIONS: Circulating DNA levels were increased in dengue patients and correlated with dengue severity. Additional studies are required to show the benefits of this biomarker in early dengue diagnosis and for the prognosis of shock complication.

  8. Elevation of soluble VCAM-1 plasma levels in children with acute dengue virus infection of varying severity.

    NARCIS (Netherlands)

    Koraka, P.; Murgue, B.; Deparis, X.; Gorp, E. van; Setiati, T.E.; Osterhaus, A.D.M.E.; Groen, J.

    2004-01-01

    Approximately 1,000 million infections with dengue viruses are estimated to occur annually. The majority of the cases develop mild disease, whereas only small proportion of the infected individuals develop severe hemorrhagic manifestations at the end of the acute phase of illness. In this study, the

  9. [Acute renal failure after dengue virus infection: A pediatric case report].

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    Nicolon, C; Broustal, E

    2016-01-01

    Dengue is an emerging, rapidly expanding disease, whose clinical and biological manifestations vary. Kidney injury is not usual but can be severe, and it is most often associated with dengue hemorrhagic fever or shock. Guadeloupe, which is located in an endemic area, experienced an epidemic from 2013 to 2014. During this outbreak, a case of renal failure during dengue was observed in a 10-year-old child. No evidence of dengue hemorrhagic fever or shock syndrome was found. The clinical and biological course improved with symptomatic treatment. The association of acute renal failure with hemolytic anemia suggested a diagnosis of hemolytic uremic syndrome. However, this could not be confirmed in the absence of thrombocytopenia and cytopathologic evidence. This case illustrates the diversity of clinical presentations of dengue, and the possibility of severe renal impairment unrelated to the usual factors encountered in dengue.

  10. Cells in Dengue Virus Infection In Vivo

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    Sansanee Noisakran

    2010-01-01

    Full Text Available Dengue has been recognized as one of the most important vector-borne emerging infectious diseases globally. Though dengue normally causes a self-limiting infection, some patients may develop a life-threatening illness, dengue hemorrhagic fever (DHF/dengue shock syndrome (DSS. The reason why DHF/DSS occurs in certain individuals is unclear. Studies in the endemic regions suggest that the preexisting antibodies are a risk factor for DHF/DSS. Viremia and thrombocytopenia are the key clinical features of dengue virus infection in patients. The amounts of virus circulating in patients are highly correlated with severe dengue disease, DHF/DSS. Also, the disturbance, mainly a transient depression, of hematological cells is a critical clinical finding in acute dengue patients. However, the cells responsible for the dengue viremia are unresolved in spite of the intensive efforts been made. Dengue virus appears to replicate and proliferate in many adapted cell lines, but these in vitro properties are extremely difficult to be reproduced in primary cells or in vivo. This paper summarizes reports on the permissive cells in vitro and in vivo and suggests a hematological cell lineage for dengue virus infection in vivo, with the hope that a new focus will shed light on further understanding of the complexities of dengue disease.

  11. Dengue virus vaccine development.

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    Yauch, Lauren E; Shresta, Sujan

    2014-01-01

    Dengue virus (DENV) is a significant cause of morbidity and mortality in tropical and subtropical regions, causing hundreds of millions of infections each year. Infections range from asymptomatic to a self-limited febrile illness, dengue fever (DF), to the life-threatening dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). The expanding of the habitat of DENV-transmitting mosquitoes has resulted in dramatic increases in the number of cases over the past 50 years, and recent outbreaks have occurred in the United States. Developing a dengue vaccine is a global health priority. DENV vaccine development is challenging due to the existence of four serotypes of the virus (DENV1-4), which a vaccine must protect against. Additionally, the adaptive immune response to DENV may be both protective and pathogenic upon subsequent infection, and the precise features of protective versus pathogenic immune responses to DENV are unknown, complicating vaccine development. Numerous vaccine candidates, including live attenuated, inactivated, recombinant subunit, DNA, and viral vectored vaccines, are in various stages of clinical development, from preclinical to phase 3. This review will discuss the adaptive immune response to DENV, dengue vaccine challenges, animal models used to test dengue vaccine candidates, and historical and current dengue vaccine approaches.

  12. Cellular immune activation in children with acute dengue virus infections is modulated by apoptosis.

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    Myint, Khin S; Endy, Timothy P; Mongkolsirichaikul, Duangrat; Manomuth, Choompun; Kalayanarooj, Siripen; Vaughn, David W; Nisalak, Ananda; Green, Sharone; Rothman, Alan L; Ennis, Francis A; Libraty, Daniel H

    2006-09-01

    Apoptosis is an important modulator of cellular immune responses during systemic viral infections. Peripheral-blood mononuclear cell (PBMC) apoptosis and plasma soluble levels of CD95, a mediator of apoptosis, were determined in sequential samples from children participating in a prospective study of dengue virus (DV) infections. During the period of defervescence, levels of PBMC apoptosis were higher in children developing dengue hemorrhagic fever (DHF), the most severe form of illness, than in those with dengue fever (DF) and other, nondengue, febrile illnesses. CD8(+) T lymphocytes made up approximately half of the peak circulating apoptotic PBMCs in DHF and DF. Maximum plasma levels of soluble CD95 were also higher in children with DHF than in those with DF. The level of PBMC apoptosis correlated with dengue disease severity. Apoptosis appears to be involved in modulation of the innate and adaptive immune responses to DV infection and is likely involved in the evolution of immune responses in other viral hemorrhagic fevers.

  13. Multiploid CD61+ cells are the pre-dominant cell lineage infected during acute dengue virus infection in bone marrow.

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    Kristina B Clark

    Full Text Available Depression of the peripheral blood platelet count during acute infection is a hallmark of dengue. This thrombocytopenia has been attributed, in part, to an insufficient level of platelet production by megakaryocytes that reside in the bone marrow (BM. Interestingly, it was observed that dengue patients experience BM suppression at the onset of fever. However, few studies focus on the interaction between dengue virus (DENV and megakaryocytes and how this interaction can lead to a reduction in platelets. In the studies reported herein, BM cells from normal healthy rhesus monkeys (RM and humans were utilized to identify the cell lineage(s that were capable of supporting virus infection and replication. A number of techniques were employed in efforts to address this issue. These included the use of viral RNA quantification, nonstructural protein and infectivity assays, phenotypic studies utilizing immunohistochemical staining, anti-differentiation DEAB treatment, and electron microscopy. Cumulative results from these studies revealed that cells in the BM were indeed highly permissive for DENV infection, with human BM having higher levels of viral production compared to RM. DENV-like particles were predominantly observed in multi-nucleated cells that expressed CD61+. These data suggest that megakaryocytes are likely the predominant cell type infected by DENV in BM, which provides one explanation for the thrombocytopenia and the dysfunctional platelets characteristic of dengue virus infection.

  14. Dengue viruses – an overview

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    Anne Tuiskunen Bäck

    2013-08-01

    Full Text Available Dengue viruses (DENVs cause the most common arthropod-borne viral disease in man with 50–100 million infections per year. Because of the lack of a vaccine and antiviral drugs, the sole measure of control is limiting the Aedes mosquito vectors. DENV infection can be asymptomatic or a self-limited, acute febrile disease ranging in severity. The classical form of dengue fever (DF is characterized by high fever, headache, stomach ache, rash, myalgia, and arthralgia. Severe dengue, dengue hemorrhagic fever (DHF, and dengue shock syndrome (DSS are accompanied by thrombocytopenia, vascular leakage, and hypotension. DSS, which can be fatal, is characterized by systemic shock. Despite intensive research, the underlying mechanisms causing severe dengue is still not well understood partly due to the lack of appropriate animal models of infection and disease. However, even though it is clear that both viral and host factors play important roles in the course of infection, a fundamental knowledge gap still remains to be filled regarding host cell tropism, crucial host immune response mechanisms, and viral markers for virulence.

  15. Plasma levels of inter-α inhibitor proteins in children with acute dengue virus infection

    NARCIS (Netherlands)

    P. Koraka (Penelope); Y.P. Lim; M.D. Shin (Michael); T.E. Setiati (Tatty); A.T.A. Mairuhu; E.C.M. van Gorp (Eric); A. Soemantri (Augustinus); A.D.M.E. Osterhaus (Albert); B.E.E. Martina (Byron)

    2010-01-01

    textabstractBackground: Inter-α inhibitor proteins (IaIp) belong to a family of protease inhibitors that are involved in the haemostatic and the vascular system. Dengue viruses (DENV) infections are characterized by coagulopathy and increased vascular permeability. In this study we measured the conc

  16. Acute brain hemorrhage in dengue

    Institute of Scientific and Technical Information of China (English)

    Somsri Wiwanitkit; Viroj Wiwanitkit

    2014-01-01

    Dengue is a tropical arboviral infection that can have severe hemorrhagic complication.Acute brain hemorrhage in dengue is rare and is a big challenge in neurosurgery.To perform surgery for management of acute brain hemorrhage in dengue is a controversial issue.Here, the authors try to summarize the previous reports on this topic and compare neurosurgery versus conservative management.

  17. Analysis of plasma viral RNA levels during acute dengue virus infection using quantitative competitor reverse transcription-polymerase chain reaction.

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    Sudiro, T M; Zivny, J; Ishiko, H; Green, S; Vaughn, D W; Kalayanarooj, S; Nisalak, A; Norman, J E; Ennis, F A; Rothman, A L

    2001-01-01

    There is increasing recognition of the potential importance of viral burden in the pathogenesis of dengue hemorrhagic fever (DHF). There is little data available, however, describing the kinetics of viral replication in humans with natural dengue virus (DV) infection. Standard procedures for measuring titers of infectious virus in clinical specimens are either laborious or insensitive. We developed a method for measurement of DV RNA in plasma samples based on reverse transcription-polymerase chain reaction (RT-PCR) using a mutant RNA target as a competitor. This technique was reproducible and accurate for samples containing any of the four DV serotypes, and could be applied to samples containing as few as 250 copies of RNA per reaction. We examined plasma viral RNA levels in 80 children with acute DV infection; sequential plasma samples were tested in 34 of these children. Plasma viral RNA levels ranged as high as 10(9) RNA copies/ml, and correlated with titers of infectious virus measured in mosquitoes (r= 0.69). Plasma viral RNA levels fell rapidly during the last several days of the febrile period. We did not find a significant difference in maximal plasma viral RNA levels between children with DHF and children with dengue fever, but peak viral RNA levels were identified in only 16 subjects. We conclude that this quantitative RT-PCR method will be valuable for further studies of natural DV infections.

  18. Evaluation of two new commercial tests for the diagnosis of acute dengue virus infection using NS1 antigen detection in human serum.

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    Philippe Dussart

    Full Text Available BACKGROUND: We compared the performance of two new commercial tests for the detection of dengue NS1 protein during the clinical phase of dengue virus (DENV infection-an immunochromatographic test allowing rapid detection of the NS1 antigen, Dengue NS1 Ag STRIP (Bio-Rad Laboratories - Marnes La Coquette, France, and a two-step sandwich-format microplate enzyme-linked immunosorbent assay (ELISA, pan-E Dengue Early ELISA (Panbio - Brisbane, Australia-with a one-step sandwich-format microplate ELISA, the Platelia Dengue NS1 Ag test (Bio-Rad. METHODS: We tested 272 serum samples from patients with dengue disease. Of these, 222 were from patients with acute infection of one of the four dengue serotypes, detected by RT-PCR and/or virus isolation. Forty-eight acute-phase serum samples from patients not infected with dengue virus were also included. RESULTS: The sensitivity of the Platelia Dengue NS1 Ag test on acute serum samples (n = 222 was 87.4% (95% confidence interval: 82.3% to 91.5%; that of Dengue NS1 Ag STRIP was 81.5% (95% CI: 75.8% to 86.4% after 15 minutes and 82.4% (95% CI: 76.8% to 87.2% after 30 minutes. Both tests had a specificity of 100% (97.5% CI, one-sided test: 92.6% to 100.0%. The pan-E Dengue Early ELISA had a sensitivity of 60.4% (95% CI: 53.4% to 66.8% and a specificity of 97.9% (95% CI: 88.9% to 99.9%. CONCLUSION: Our findings support the use of diagnostic tools based on the NS1 antigen detection for the diagnosis of acute DENV infection. The immunochromatographic test, Dengue NS1 Ag STRIP-the first rapid diagnostic test for DENV infection-was highly sensitive and specific, and would therefore be a suitable first-line test in the field. The pan-E Dengue Early ELISA was less sensitive than the Platelia test; this two-step ELISA should be combined with DENV IgM antibody detection for the diagnosis of DENV infection.

  19. Dengue and Chikungunya Virus Infections among Young Febrile Adults Evaluated for Acute HIV-1 Infection in Coastal Kenya

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    Ngoi, Carolyne N.; Price, Matt A.; Fields, Barry; Bonventure, Juma; Ochieng, Caroline; Mwashigadi, Grace; Hassan, Amin S.; Thiong’o, Alexander N.; Micheni, Murugi; Mugo, Peter; Graham, Susan; Sanders, Eduard J.

    2016-01-01

    Background Fever is common among patients seeking care in sub-Saharan Africa (sSA), but causes other than malaria are rarely diagnosed. We assessed dengue and chikungunya virus infections among young febrile adults evaluated for acute HIV infection (AHI) and malaria in coastal Kenya. Methods We tested plasma samples obtained in a cross-sectional study from febrile adult patients aged 18–35 years evaluated for AHI and malaria at urgent care seeking at seven health facilities in coastal Kenya in 2014–2015. Dengue virus (DENV) and chikungunya virus (CHIKV) were amplified using quantitative real-time reverse-transcription polymerase chain reaction. We conducted logistic regression analyses to determine independent predictors of dengue virus infection. Results 489 samples that were negative for both AHI and malaria were tested, of which 43 (8.8%, 95% confidence interval [CI]: 6.4–11.7) were positive for DENV infection. No participant was positive for CHIKV infection. DENV infections were associated with clinic visits in the rainy season (adjusted odds ratio (AOR) = 3.0, 95% CI: 1.3–6.5) and evaluation at a private health facility (AOR 5.2, 95% CI: 2.0–13.1) or research health facility (AOR = 25.6, 95% CI: 8.9–73.2) instead of a public health facility. Conclusion A high prevalence of DENV infections was found in febrile young adult patients evaluated for AHI. Our data suggests that DENV, along with AHI and malaria, should be considered in the differential diagnosis of the adult patient seeking care for fever in coastal Kenya. PMID:27942016

  20. Dengue fever presenting as acute acalculus cholecystitis.

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    Joshipura, Vismit P; Soni, Harshad N; Patel, Nitin R; Haribhakti, Sanjiv P

    2007-06-01

    Classically dengue fever presents as fever with myalgia. A patient of dengue fever presented with classical symptoms and signs of acute acalculous cholecystitis. Serology and ultrasound examination identified dengue as the aetiology. Patient was treated successfully by conservative measures.

  1. Dengue hemorrhagic fever and acute hepatitis: a case report

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    Maria Paula Gomes Mourão

    2004-12-01

    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.

  2. Concurrent infections by all four dengue virus serotypes during an outbreak of dengue in 2006 in Delhi, India

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    Guleria Randeep

    2008-01-01

    Full Text Available Abstract Background Co-circulation of multiple dengue virus serotypes has been reported from many parts of the world including India, however concurrent infection with more than one serotype of dengue viruses in the same individual is rarely documented. An outbreak of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS occurred in and around Delhi in 2006. This is the first report from India with high percentage of concurrent infections with different dengue virus serotypes circulating during one outbreak. Results Acute phase sera from patients were tested for the presence of dengue virus RNA by RT-PCR assay. Of the 69 samples tested for dengue virus RNA, 48 (69.5% were found to be positive. All the four dengue virus serotypes were found to be co-circulating in this outbreak with DENV-3 being the predominant serotype. In addition in 9 of 48 (19% dengue virus positive samples, concurrent infection with more than one dengue virus serotype were identified. Conclusion This is the first report in which concurrent infections with different dengue virus serotypes is being reported during an outbreak from India. Delhi is now truly hyperendemic for dengue.

  3. Detection of dengue virus in platelets isolated from dengue patients.

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    Noisakran, Sansanee; Gibbons, Robert V; Songprakhon, Pucharee; Jairungsri, Aroonroong; Ajariyakhajorn, Chuanpis; Nisalak, Ananda; Jarman, Richard G; Malasit, Prida; Chokephaibulkit, Kulkanya; Perng, Guey Chuen

    2009-03-01

    Though thrombocytopenia or dysfunction of platelets is common in dengue virus infection, the role of platelets has not been established. We enrolled 33 hospitalized children with serologically confirmed dengue virus infection. Blood specimens were collected during hospitalization. Platelets and plasma were isolated from the whole blood. Detection of dengue virus in plasma and platelets was carried out by RT-PCR with primers that can differentiate different dengue serotypes simultaneously, and by electron transmission microscopy (EM). Dengue viral RNA was detected in the platelets and plasma by conventional RT-PCR. A significantly higher percentage of dengue viral RNA was detected in platelets than in plasma (p = 0.03). Platelets isolated 5 days after onset of fever were most likely positive for viral RNA. Concurrent infection or co-circulation with multiple dengue serotypes was observed in 12% of patients. Infrequently, negative-stranded dengue viral RNA was detected in platelets and in plasma. Importantly, EM confirmed the presence of dengue viral-like particles inside platelets prepared from dengue patients. Our findings suggest the presence of dengue virus in platelets may be associated with the dysfunction of platelets observed in dengue patients.

  4. Acute neuromuscular weakness associated with dengue infection

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    Harmanjit Singh Hira

    2012-01-01

    Full Text Available Background: Dengue infections may present with neurological complications. Whether these are due to neuromuscular disease or electrolyte imbalance is unclear. Materials and Methods: Eighty-eight patients of dengue fever required hospitalization during epidemic in year 2010. Twelve of them presented with acute neuromuscular weakness. We enrolled them for study. Diagnosis of dengue infection based on clinical profile of patients, positive serum IgM ELISA, NS1 antigen, and sero-typing. Complete hemogram, kidney and liver functions, serum electrolytes, and creatine phosphokinase (CPK were tested. In addition, two patients underwent nerve conduction velocity (NCV test and electromyography. Results: Twelve patients were included in the present study. Their age was between 18 and 34 years. Fever, myalgia, and motor weakness of limbs were most common presenting symptoms. Motor weakness developed on 2 nd to 4 th day of illness in 11 of 12 patients. In one patient, it developed on 10 th day of illness. Ten of 12 showed hypokalemia. One was of Guillain-Barré syndrome and other suffered from myositis; they underwent NCV and electromyography. Serum CPK and SGOT raised in 8 out of 12 patients. CPK of patient of myositis was 5098 IU. All of 12 patients had thrombocytopenia. WBC was in normal range. Dengue virus was isolated in three patients, and it was of serotype 1. CSF was normal in all. Within 24 hours, those with hypokalemia recovered by potassium correction. Conclusions: It was concluded that the dengue virus infection led to acute neuromuscular weakness because of hypokalemia, myositis, and Guillain-Barré syndrome. It was suggested to look for presence of hypokalemia in such patients.

  5. Dengue virus: A global human threat: Review of literature

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    Hasan, Shamimul; Jamdar, Sami Faisal; Alalowi, Munther; Al Ageel Al Beaiji, Sadun Mohammad

    2016-01-01

    Dengue is an acute viral illness caused by RNA virus of the family Flaviviridae and spread by Aedes mosquitoes. Presenting features may range from asymptomatic fever to dreaded complications such as hemorrhagic fever and shock. A cute-onset high fever, muscle and joint pain, myalgia, cutaneous rash, hemorrhagic episodes, and circulatory shock are the commonly seen symptoms. Oral manifestations are rare in dengue infection; however, some cases may have oral features as the only presenting manifestation. Early and accurate diagnosis is critical to reduce mortality. Although dengue virus infections are usually self-limiting, dengue infection has come up as a public health challenge in the tropical and subtropical nations. This article provide a detailed overview on dengue virus infections, varied clinical manifestations, diagnosis, differential diagnosis, and prevention and treatment. PMID:27011925

  6. Acute dengue virus 2 infection in Gabonese patients is associated with an early innate immune response, including strong interferon alpha production

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    Nkoghe Dieudonné

    2010-12-01

    Full Text Available Abstract Background Dengue is now a leading cause of morbidity and mortality throughout the tropics. We conducted the first ex vivo study of dengue fever (DF in African patients infected during the first Gabonese dengue virus 2 (DENV-2 outbreak in 2007, in order to investigate cytokine production, including the antiviral cytokine IFN-α, reported to be a potent inhibitor of DENV replication in vitro. Methods Levels of 50 cytokines, chemokines and growth factors were measured in plasma from 36 patients with DENV-2 infection, and in uninfected controls, using Luminex multiplex technology. The results were interpreted according to the day of sampling after symptom onset. PBMC from six patients were also studied for T lymphocyte cell surface marker expression by flow cytometry. Results Acute DENV-2 infection elicited high levels of several pro-inflammatory cytokines (IL-6 and IL-17, chemokines (MIF, RANTES, IP-10 and MCP-1 and growth factors (G-CSF, GM-CSF and VEGF-A. We also observed high levels of IFN-α for the first time in adult DF patients, and CD4+ and CD8+ T cell activation at symptom onset. Conclusion Acute DENV-2 infection in African patients elicits a strong innate response involving IFN-α production, as well as an adaptive immune response.

  7. Dengue-1 virus isolation during first dengue fever outbreak on Easter Island, Chile.

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    Perret, Cecilia; Abarca, Katia; Ovalle, Jimena; Ferrer, Pablo; Godoy, Paula; Olea, Andrea; Aguilera, Ximena; Ferrés, Marcela

    2003-11-01

    Dengue virus was detected for the first time in Chile, in an outbreak of dengue fever on Easter Island. The virus was isolated in tissue culture and characterized by reverse transcription-polymerase chain reaction as being dengue type 1.

  8. Dengue-1 Virus Isolation during First Dengue Fever Outbreak on Easter Island, Chile

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    Perret, Cecilia; Abarca, Katia; Ovalle, Jimena; Ferrer, Pablo; Godoy, Paula; Olea, Andrea; Aguilera, Ximena; Ferrés, Marcela

    2003-01-01

    Dengue virus was detected for the first time in Chile, in an outbreak of dengue fever on Easter Island. The virus was isolated in tissue culture and characterized by reverse transcription–polymerase chain reaction as being dengue type 1.

  9. Dengue virus: A global human threat: Review of literature

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    Hasan, Shamimul; Jamdar, Sami Faisal; Alalowi, Munther; Al Ageel Al Beaiji, Sadun Mohammad

    2016-01-01

    Dengue is an acute viral illness caused by RNA virus of the family Flaviviridae and spread by Aedes mosquitoes. Presenting features may range from asymptomatic fever to dreaded complications such as hemorrhagic fever and shock. A cute-onset high fever, muscle and joint pain, myalgia, cutaneous rash, hemorrhagic episodes, and circulatory shock are the commonly seen symptoms. Oral manifestations are rare in dengue infection; however, some cases may have oral features as the only presenting mani...

  10. Help Control Mosquitoes that Spread Dengue, Chikungunya, and Zika Viruses

    Science.gov (United States)

    Help Control Mosquitoes that Spread Dengue, Chikungunya, and Zika Viruses B Z Z Z Z . Aside from ... or Aedes albopictus ) can spread dengue, chikungunya, or Zika viruses. People become infected with dengue, chikungunya, or ...

  11. Dengue virus antibodies enhance Zika virus infection

    Science.gov (United States)

    Paul, Lauren M; Carlin, Eric R; Jenkins, Meagan M; Tan, Amanda L; Barcellona, Carolyn M; Nicholson, Cindo O; Michael, Scott F; Isern, Sharon

    2016-01-01

    For decades, human infections with Zika virus (ZIKV), a mosquito-transmitted flavivirus, were sporadic, associated with mild disease, and went underreported since symptoms were similar to other acute febrile diseases. Recent reports of severe disease associated with ZIKV have greatly heightened awareness. It is anticipated that ZIKV will continue to spread in the Americas and globally where competent Aedes mosquito vectors are found. Dengue virus (DENV), the most common mosquito-transmitted human flavivirus, is both well-established and the source of outbreaks in areas of recent ZIKV introduction. DENV and ZIKV are closely related, resulting in substantial antigenic overlap. Through antibody-dependent enhancement (ADE), anti-DENV antibodies can enhance the infectivity of DENV for certain classes of immune cells, causing increased viral production that correlates with severe disease outcomes. Similarly, ZIKV has been shown to undergo ADE in response to antibodies generated by other flaviviruses. We tested the neutralizing and enhancing potential of well-characterized broadly neutralizing human anti-DENV monoclonal antibodies (HMAbs) and human DENV immune sera against ZIKV using neutralization and ADE assays. We show that anti-DENV HMAbs, cross-react, do not neutralize, and greatly enhance ZIKV infection in vitro. DENV immune sera had varying degrees of neutralization against ZIKV and similarly enhanced ZIKV infection. Our results suggest that pre-existing DENV immunity may enhance ZIKV infection in vivo and may lead to increased disease severity. Understanding the interplay between ZIKV and DENV will be critical in informing public health responses and will be particularly valuable for ZIKV and DENV vaccine design and implementation strategies. PMID:28090318

  12. RNAi:antiviral therapy against dengue virus

    Institute of Scientific and Technical Information of China (English)

    Sobia Idrees; Usman A Ashfaq

    2013-01-01

    Dengue virus infection has become a global threat affecting around 100 countries in the world. Currently, there is no licensed antiviral agent available against dengue. Thus, there is a strong need to develop therapeutic strategies that can tackle this life threatening disease. RNA interference is an important and effective gene silencing process which degrades targeted RNA by a sequence specific process. Several studies have been conducted during the last decade to evaluate the efficiency of siRNA in inhibiting dengue virus replication. This review summarizes siRNAs as a therapeutic approach against dengue virus serotypes and concludes that siRNAs against virus and host genes can be next generation treatment of dengue virus infection.

  13. Acute neuromuscular weakness associated with dengue infection

    OpenAIRE

    Harmanjit Singh Hira; Amandeep Kaur; Anuj Shukla

    2012-01-01

    Background: Dengue infections may present with neurological complications. Whether these are due to neuromuscular disease or electrolyte imbalance is unclear. Materials and Methods: Eighty-eight patients of dengue fever required hospitalization during epidemic in year 2010. Twelve of them presented with acute neuromuscular weakness. We enrolled them for study. Diagnosis of dengue infection based on clinical profile of patients, positive serum IgM ELISA, NS1 antigen, and sero-typing. Complete ...

  14. Dengue NS1 and prM antibodies increase the sensitivity of acute dengue diagnosis test and differentiate from Japanese encephalitis infection.

    Science.gov (United States)

    Gowri Sankar, S; Balaji, T; Venkatasubramani, K; Thenmozhi, V; Dhananjeyan, K J; Paramasivan, R; Tyagi, B K; John Vennison, S

    2014-05-01

    Accurate and early diagnosis of dengue infection is essential for dengue case management. In outbreak conditions, it is essential to include two different tests to diagnose dengue and the choice depends on the number of days after the onset of illness in which the sample is collected. During the laboratory diagnosis of dengue in late acute and convalescent phase by MAC-ELISA, it is necessary to rule out possible cross reactions of closely related flavivirus, such as Japanese encephalitis virus which is commonly co-circulating. In the present investigation, the usefulness of dengue virus NS1 and prM antibodies in diagnosing and differentiating dengue from Japanese encephalitis infection was assessed using samples collected during out-breaks. It was shown here that, detection of antibodies against dengue NS1 and prM proteins increases the sensitivity of dengue diagnosis until 15days. Moreover, detection of antibodies against both proteins was able to differentiate dengue from Japanese encephalitis infection.

  15. Identifizierung neuer Dengue Virus Typ-2 Proteaseinhibitoren

    OpenAIRE

    Snitko, Mariya

    2015-01-01

    Weltweit leben ca. 2,5 Mrd. Menschen im Dengue Virus Verbreitungsgebiet. Dengue Virus Infektionen führen zum Dengue Fieber und können bei Re-Infektionen mit anderen Serotypen das sog. Dengue Schocksyndrom mit einer Letalität von 10% verursachen. Momentan stehen jedoch weder Impfstoffe noch antivirale Substanzen zur Verfügung. In der vorliegenden Arbeit sollten DENV2-Proteaseinhibitoren entwickelt werden. Dazu wurde ein in vitro DENV Proteasetest etabliert, für den die DENV Protease i...

  16. Acute gingival bleeding as a complication of dengue hemorrhagic fever

    Directory of Open Access Journals (Sweden)

    Saif Khan

    2013-01-01

    Full Text Available Dengue fever is mosquito borne disease caused by dengue virus (DENV of Flaviviridae family. The clinical manifestations range from fever to severe hemorrhage, shock and death. Here, we report a case of 20-year-old male patient undergoing orthodontic treatment presenting with acute gingival bleeding with a history of fever, weakness, backache, retro orbital pain and ecchymosis over his right arm. The hematological investigations revealed anemia, thrombocytopenia and positive dengue non-structural protein-1 antigen and also positive immunoglobulin M and immunoglobulin G antibodies for DENV. Patient was diagnosed as a case of dengue hemorrhagic fever and was immediately referred for appropriate management. This case report emphasizes the importance of taking correct and thorough medical history.

  17. Evasion of the human innate immune system by dengue virus

    OpenAIRE

    Pagni, Sarah; Fernandez-Sesma, Ana

    2012-01-01

    Dengue virus is a worldwide health problem, with billions of people at risk annually. Dengue virus causes a spectrum of diseases, namely dengue fever, dengue hemorrhagic fever and dengue shock syndrome with the latter two being linked to death. Understanding how dengue is able to evade the immune system and cause enhanced severity of disease is the main topics of interest in the Fernandez-Sesma laboratory at Mount Sinai School of Medicine. Using primary human immune cells, our group investiga...

  18. Dengue virus identification by transmission electron microscopy and molecular methods in fatal dengue hemorrhagic fever.

    Science.gov (United States)

    Limonta, D; Falcón, V; Torres, G; Capó, V; Menéndez, I; Rosario, D; Castellanos, Y; Alvarez, M; Rodríguez-Roche, R; de la Rosa, M C; Pavón, A; López, L; González, K; Guillén, G; Diaz, J; Guzmán, M G

    2012-12-01

    Dengue virus is the most significant virus transmitted by arthropods worldwide and may cause a potentially fatal systemic disease named dengue hemorrhagic fever. In this work, dengue virus serotype 4 was detected in the tissues of one fatal dengue hemorrhagic fever case using electron immunomicroscopy and molecular methods. This is the first report of dengue virus polypeptides findings by electron immunomicroscopy in human samples. In addition, not-previously-documented virus-like particles visualized in spleen, hepatic, brain, and pulmonary tissues from a dengue case are discussed.

  19. Scientists Create Mosquitoes Resistant to Dengue Virus

    Science.gov (United States)

    ... to the dengue virus, which might eventually help control the spread of the disease in humans. The team at Johns Hopkins Bloomberg School of Public Health in Baltimore genetically modified Aedes aegypti mosquitoes to boost their natural ability to fight ...

  20. Acute glomerulonephritis in dengue hemorrhagic fever: A rare case report

    Directory of Open Access Journals (Sweden)

    K R Meena

    2013-01-01

    Full Text Available An 11-year-old male child presented with fever, bodyache, swelling over the whole body, and oliguria. He had hypertension. Urine microscopy showed hematuria and glomerular casts. Renal functions were deranged and had low complement C3 level. Chest X-ray showed plural effusion and ultrasonography abdomen showed mild ascitis. The immunoglobulin (IgM and IgG enzyme-linked immunosorbent essay for dengue virus were positive. Diagnosis of dengue hemorrhagic fever with acute glomerulonephritis was made. He was managed with maintenance fluid, antihypertensive medicine and supportive care. He recovered gradually and was discharged 12 days after admission.

  1. Heterotypic Dengue Infection with Live Attenuated Monotypic Dengue Virus Vaccines: Implications for Vaccination of Populations in Areas Where Dengue Is Endemic

    OpenAIRE

    Anna P Durbin; Schmidt, Alexander; Elwood, Dan; Wanionek, Kimberli A.; Lovchik, Janece; Thumar, Bhavin; Murphy, Brian R.; Whitehead, Stephen S.

    2011-01-01

    Background. Because infection with any of the 4 Dengue virus serotypes may elicit both protective neutralizing antibodies and nonneutralizing antibodies capable of enhancing subsequent heterotypic Dengue virus infections, the greatest risk for severe dengue occurs during a second, heterotypic Dengue virus infection. It remains unclear whether the replication of live attenuated vaccine viruses will be similarly enhanced when administered to Dengue-immune individuals.

  2. Urban epidemic of dengue virus serotype 3 infection, Senegal, 2009.

    Science.gov (United States)

    Faye, Ousmane; Ba, Yamar; Faye, Oumar; Talla, Cheikh; Diallo, Diawo; Chen, Rubing; Mondo, Mireille; Ba, Rouguiétou; Macondo, Edgard; Siby, Tidiane; Weaver, Scott C; Diallo, Mawlouth; Sall, Amadou Alpha

    2014-03-01

    An urban epidemic of dengue in Senegal during 2009 affected 196 persons and included 5 cases of dengue hemorrhagic fever and 1 fatal case of dengue shock syndrome. Dengue virus serotype 3 was identified from all patients, and Aedes aegypti mosquitoes were identified as the primary vector of the virus.

  3. Release of Dengue Virus Genome Induced by a Peptide Inhibitor

    OpenAIRE

    Shee-Mei Lok; Costin, Joshua M.; Hrobowski, Yancey M.; Hoffmann, Andrew R.; Rowe, Dawne K.; Petra Kukkaro; Heather Holdaway; Paul Chipman; Krystal A Fontaine; Michael R Holbrook; Garry, Robert F; Victor Kostyuchenko; Wimley, William C.; Sharon Isern; Rossmann, Michael G.

    2012-01-01

    Dengue virus infects approximately 100 million people annually, but there is no available therapeutic treatment. The mimetic peptide, DN59, consists of residues corresponding to the membrane interacting, amphipathic stem region of the dengue virus envelope (E) glycoprotein. This peptide is inhibitory to all four serotypes of dengue virus, as well as other flaviviruses. Cryo-electron microscopy image reconstruction of dengue virus particles incubated with DN59 showed that the virus particles w...

  4. Detection of Saint Louis encephalitis virus in dengue-suspected cases during a dengue 3 outbreak.

    Science.gov (United States)

    Terzian, Ana Carolina Bernardes; Mondini, Adriano; Bronzoni, Roberta Vieira de Moraes; Drumond, Betânia Paiva; Ferro, Bianca Piovezan; Cabrera, Eliana Márcia Sotello; Figueiredo, Luis Tadeu Moraes; Chiaravalloti-Neto, Francisco; Nogueira, Maurício Lacerda

    2011-03-01

    Arboviruses are frequently associated with outbreaks in humans and represent a serious public health problem. Among the Brazilian arboviruses, Mayaro virus, Dengue virus (DENV), Yellow Fever virus, Rocio virus, Saint Louis Encephalitis virus (SLEV), and Oropouche virus are responsible for most of human cases. All these arboviruses usually produce undistinguishable acute febrile illness, especially in the acute phase of infection. In this study we investigated the presence of arboviruses in sera of 519 patients presenting acute febrile illness, during a dengue outbreak in São José do Rio Preto City (São Paulo, Brazil). A multiplex-nested RT-polymerase chain reaction assay was applied to detect and identify the main Brazilian arboviruses (Flavivirus, Alphavirus, and Orthobunyavirus genera). The molecular analysis showed that 365 samples were positive to DENV-3, 5 to DENV-2, and 8 to SLEV. Among the positive samples, one coinfection was detected between DENV-2 and DENV-3. The phylogenetic analysis of the SLEV envelope gene indicated that the virus circulating in city is related to lineage V strains. These results indicated that during that large DENV-3 outbreak in 2006, different arboviruses cocirculated causing human disease. Thus, it is necessary to have an efficient surveillance system to control the dissemination of these arboviruses in the population.

  5. Hyperferritinaemia in Dengue Virus Infected Patients Is Associated with Immune Activation and Coagulation Disturbances

    NARCIS (Netherlands)

    C.A.M. van de Weg (Cornelia A.M.); R.M.H.G. Huits (Ralph M. H. G.); C.S. Pannuti (Cláudio); R.M. Brouns (Rosalba M.); R.W.A. van den Berg (Riemsdijk W. A.); H.J. van den Ham; B.E.E. Martina (Byron); A.D.M.E. Osterhaus (Albert); M.G. Netea (Mihai); J.C.M. Meijers; E.C.M. van Gorp (Eric); E.G. Kallas (Esper)

    2014-01-01

    textabstractDuring a dengue outbreak on the Caribbean island Aruba, highly elevated levels of ferritin were detected in dengue virus infected patients. Ferritin is an acute-phase reactant and hyperferritinaemia is a hallmark of diseases caused by extensive immune activation, such as haemophagocytic

  6. Hyperferritinaemia in dengue virus infected patients is associated with immune activation and coagulation disturbances

    NARCIS (Netherlands)

    Weg, C.A. van de; Huits, R.M.; Pannuti, C.S.; Brouns, R.M.; Berg, R.W.A. van den; Ham, H.J. van den; Martina, B.E.; Osterhaus, A.D.; Netea, M.G.; Meijers, J.C.; Gorp, E.C. van; Kallas, E.G.

    2014-01-01

    BACKGROUND: During a dengue outbreak on the Caribbean island Aruba, highly elevated levels of ferritin were detected in dengue virus infected patients. Ferritin is an acute-phase reactant and hyperferritinaemia is a hallmark of diseases caused by extensive immune activation, such as haemophagocytic

  7. Acute atrial fibrillation during dengue hemorrhagic fever

    Directory of Open Access Journals (Sweden)

    Veloso Henrique Horta

    2003-01-01

    Full Text Available Dengue fever is a viral infection transmitted by the mosquito, Aedes aegypti. Cardiac rhythm disorders, such as atrioventricular blocks and ventricular ectopic beats, appear during infection and are attributed to viral myocarditis. However, supraventricular arrhythmias have not been reported. We present a case of acute atrial fibrillation, with a rapid ventricular rate, successfully treated with intravenous amiodarone, in a 62-year-old man with dengue hemorrhagic fever, who had no structural heart disease.

  8. Autoimmune pathogenesis in dengue virus infection.

    Science.gov (United States)

    Lin, Chiou-Feng; Wan, Shu-Wen; Cheng, Hsien-Jen; Lei, Huan-Yao; Lin, Yee-Shin

    2006-01-01

    The pathogenic mechanisms of dengue hemorrhagic fever and dengue shock syndrome (DHF/DSS) caused by dengue virus (DV) infection remain unresolved. Patients with DHF/DSS are characterized by several manifestations, including severe thrombocytopenia, vascular leakage, and hepatomegaly. In addition to the effect of virus load and virus variation, abnormal immune responses of the host after DV infection may also account for the progression of DHF/DSS. Actually, viral autoimmunity is involved in the pathogenesis of numerous viral infections, such as human immunodeficiency virus, human hepatitis C virus, human cytomegalovirus, herpes simplex virus, Epstein- Barr virus, and DV. In this review, we discuss the implications of autoimmunity in dengue pathogenesis. Antibodies directed against DV nonstructural protein 1 (NS1) showed cross-reactivity with human platelets and endothelial cells, which lead to platelet and endothelial cell damage and inflammatory activation. Based on these findings, we hypothesize that anti-DV NS1 is involved in the pathogenesis of DF and DHF/DSS, and this may provide important information in dengue vaccine development.

  9. The status of dengue fever virus in South Africa--serological studies and diagnosis of a case of dengue fever.

    Science.gov (United States)

    Blackburn, N K; Meenehan, G; Aldridge, N

    1987-01-01

    To assess the possibility of a dengue epidemic occurring in South Africa 3 groups of survey sera and 2 groups of patients' sera, from a dengue high risk area of South Africa, were tested for antibodies to several flaviviruses. 3.8% (75/1951) of the survey sera and 9.2% (26/282) of the patients' sera had haemagglutination inhibition antibodies to one or more of the flaviviruses tested. One of 1951 survey sera had a spectrum of complement fixation antibody consistent with a primary dengue infection, and 5 of 282 patients' sera also had complement fixation antibodies to flavivirus antigens. These 5 positive patients had recently travelled to India but in only one was there an antibody spectrum unequivocably consistent with a primary dengue infection. Dengue virus type 1 was successfully isolated from this patient's acute serum. The susceptibility of the population to dengue virus infection, the presence of the main vector of dengue virus and the occurrence of imported cases of dengue fever emphasize the need for continuous vigilance.

  10. Temporal distribution of dengue virus serotypes in Colombian endemic area and dengue incidence: re-introduction of dengue-3 associated to mild febrile illness and primary infection

    Directory of Open Access Journals (Sweden)

    Raquel Elvira Ocazionez

    2006-11-01

    Full Text Available We have investigated the temporal distribution of dengue (DEN virus serotypes in the department (state of Santander, Colombia, in relation to dengue incidence, infection pattern, and severity of disease. Viral isolation was attended on a total of 1452 acute serum samples collected each week from 1998 to 2004. The infection pattern was evaluated in 596 laboratory-positive dengue cases using an IgG ELISA, and PRNT test. The dengue incidence was documented by the local health authority. Predominance of DEN-1 in 1998 and DEN-3 re-introduction and predominance in 2001-2003 coincided with outbreaks. Predominance of DEN-2 in 2000-2001 coincided with more dengue hemorrhagic fever (DHF. DEN-4 was isolated in 2000-2001 and 2004 but was not predominant. There was an annual increase of primary dengue infections (from 13.7 to 81.4% that correlated with frequency of DEN-3 (r = 0.83; P = 0.038. From the total number of primary dengue infections DEN-3 (81.3% was the most frequent serotype. DHF was more frequent in DEN-2 infected patients than in DEN-3 infected patients: 27.5 vs 10.9% (P < 0.05. DEN-3 viruses belonged to subtype C (restriction site-specific-polymerase chain reaction like viruses isolated in Sri-Lanka and other countries in the Americas. Our findings show the importance of continuous virological surveillance to identify the risk factors of dengue epidemics and severity.

  11. Molecular Characterisation of Chikungunya Virus Infections in Trinidad and Comparison of Clinical and Laboratory Features with Dengue and Other Acute Febrile Cases.

    Science.gov (United States)

    Sahadeo, Nikita; Mohammed, Hamish; Allicock, Orchid M; Auguste, Albert J; Widen, Steven G; Badal, Kimberly; Pulchan, Krishna; Foster, Jerome E; Weaver, Scott C; Carrington, Christine V F

    2015-11-01

    Local transmission of Chikungunya virus (CHIKV) was first documented in Trinidad and Tobago (T&T) in July 2014 preceding a large epidemic. At initial presentation, it is difficult to distinguish chikungunya fever (CHIKF) from other acute undifferentiated febrile illnesses (AUFIs), including life-threatening dengue disease. We characterised and compared dengue virus (DENV) and CHIKV infections in 158 patients presenting with suspected dengue fever (DF) and CHIKF at a major hospital in T&T, and performed phylogenetic analyses on CHIKV genomic sequences recovered from 8 individuals. The characteristics of patients with and without PCR-confirmed CHIKV were compared using Pearson's χ2 and student's t-tests, and adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were determined using logistic regression. We then compared signs and symptoms of people with RT-qPCR-confirmed CHIKV and DENV infections using the Mann-Whitney U, Pearson's χ2 and Fisher's exact tests. Among the 158 persons there were 8 (6%) RT-qPCR-confirmed DENV and 30 (22%) RT-qPCR-confirmed CHIKV infections. Phylogenetic analyses showed that the CHIKV strains belonged to the Asian genotype and were most closely related to a British Virgin Islands strain isolated at the beginning of the 2013/14 outbreak in the Americas. Compared to persons who were RT-qPCR-negative for CHIKV, RT-qPCR-positive individuals were significantly more likely to have joint pain (aOR: 4.52 [95% CI: 1.28-16.00]), less likely to be interviewed at a later stage of illness (days post onset of fever--aOR: 0.56 [0.40-0.78]) and had a lower white blood cell count (aOR: 0.83 [0.71-0.96]). Among the 38 patients with RT-qPCR-confirmed CHIKV or DENV, there were no significant differences in symptomatic presentation. However when individuals with serological evidence of recent DENV or CHIKV infection were included in the analyses, there were key differences in clinical presentation between CHIKF and other AUFIs including DF, which

  12. Dengue Virus Seroconversion in Travelers to Dengue-Endemic Areas.

    Science.gov (United States)

    Olivero, Rosemary M; Hamer, Davidson H; MacLeod, William B; Benoit, Christine M; Sanchez-Vegas, Carolina; Jentes, Emily S; Chen, Lin H; Wilson, Mary E; Marano, Nina; Yanni, Emad A; Ooi, Winnie W; Karchmer, Adolf W; Kogelman, Laura; Barnett, Elizabeth D

    2016-11-02

    We conducted a prospective study to measure dengue virus (DENV) antibody seroconversion in travelers to dengue-endemic areas. Travelers seen in the Boston Area Travel Medicine Network planning to visit dengue-endemic countries for ≥ 2 weeks were enrolled from 2009 to 2010. Pre- and post-travel blood samples and questionnaires were collected. Post-travel sera were tested for anti-DENV IgG by indirect IgG enzyme-linked immunosorbent assay (ELISA) and anti-DENV IgM by capture IgM ELISA. Participants with positive post-travel anti-DENV IgG or IgM were tested for pre-travel anti-DENV IgG and IgM; they were excluded from the seroconversion calculation if either pre-travel anti-DENV IgG or IgM were positive. Paired sera and questionnaires were collected for 62% (589/955) of enrolled travelers. Most participants were 19-64 years of age, female, and white. The most common purposes of travel were tourism and visiting friends and relatives; most trips were to Asia or Africa. Median length of travel was 21 days. DENV antibody seroconversion by either anti-DENV IgM or IgG ELISA was 2.9-6.8%; lower range percent excluded potential false-positive anti-DENV IgG due to receipt of yellow fever or Japanese encephalitis vaccines at enrollment; upper range percent excluded proven false-positive anti-DENV IgM. Eighteen percent of those with seroconversion reported dengue-like symptoms. Seroconversion was documented for travel to Africa as well as countries and regions known to be highly dengue endemic (India, Brazil, southeast Asia). Given widespread risk of dengue, travel medicine counseling should include information on risk of dengue in endemic areas and advice on preventing insect bites and seeking prompt medical attention for febrile illness.

  13. Molecular epidemiology of dengue viruses in Brazil

    Directory of Open Access Journals (Sweden)

    Rita Maria Ribeiro Nogueira

    2000-01-01

    Full Text Available Dengue viruses (DEN are found as four antigenically distinct serotypes designated DEN-1, 2, 3, and 4. Laboratory evidence that strain-intratypical variation occurs among DEN viruses has been demonstrated since the 1970s, although only with the advances in molecular technologies has it been possible to determine the genetic variability of each serotype. Genotypical identification has proven to be a useful tool for determining the origin and spread of epidemics and to correlate virulence of strains. In this report we present the results of molecular epidemiological studies with the DEN-1 and DEN-2 viruses that caused dengue epidemics in Brazil during the last decade.

  14. Dengue virus-specific cross-reactive CD8+ human cytotoxic T lymphocytes.

    OpenAIRE

    Bukowski, J F; Kurane, I; Lai, C J; Bray, M.; Falgout, B.; Ennis, F A

    1989-01-01

    Stimulation with live dengue virus of peripheral blood mononuclear cells from a dengue virus type 4-immune donor generated virus-specific, serotype-cross-reactive, CD8+, class I-restricted cytotoxic T lymphocytes (CTL) capable of lysing dengue virus-infected cells and cells pulsed with dengue virus antigens of all four serotypes. These CTL lysed autologous fibroblasts infected with vaccinia virus-dengue virus recombinant viruses containing the E gene or several nonstructural dengue virus type...

  15. Visualizing dengue virus through Alexa Fluor labeling.

    Science.gov (United States)

    Zhang, Summer; Tan, Hwee Cheng; Ooi, Eng Eong

    2011-07-09

    The early events in the interaction between virus and cell can have profound influence on the outcome of infection. Determining the factors that influence this interaction could lead to improved understanding of disease pathogenesis and thus influence vaccine or therapeutic design. Hence, the development of methods to probe this interaction would be useful. Recent advancements in fluorophores development and imaging technology can be exploited to improve our current knowledge on dengue pathogenesis and thus pave the way to reduce the millions of dengue infections occurring annually. The enveloped dengue virus has an external scaffold consisting of 90 envelope glycoprotein (E) dimers protecting the nucleocapsid shell, which contains a single positive strand RNA genome. The identical protein subunits on the virus surface can thus be labeled with an amine reactive dye and visualized through immunofluorescent microscopy. Here, we present a simple method of labeling of dengue virus with Alexa Fluor succinimidyl ester dye dissolved directly in a sodium bicarbonate buffer that yielded highly viable virus after labeling. There is no standardized procedure for the labeling of live virus and existing manufacturer's protocol for protein labeling usually requires the reconstitution of dye in dimethyl sulfoxide. The presence of dimethyl sulfoxide, even in minute quantities, can block productive infection of virus and also induce cell cytotoxicity. The exclusion of the use of dimethyl sulfoxide in this protocol thus reduced this possibility. Alexa Fluor dyes have superior photostability and are less pH-sensitive than the common dyes, such as fluorescein and rhodamine, making them ideal for studies on cellular uptake and endosomal transport of the virus. The conjugation of Alexa Fluor dye did not affect the recognition of labeled dengue virus by virus-specific antibody and its putative receptors in host cells. This method could have useful applications in virological studies.

  16. Dengue-1 Virus Isolation during First Dengue Fever Outbreak on Easter Island, Chile

    Science.gov (United States)

    Abarca, Katia; Ovalle, Jimena; Ferrer, Pablo; Godoy, Paula; Olea, Andrea; Aguilera, Ximena; Ferrés, Marcela

    2003-01-01

    Dengue virus was detected for the first time in Chile, in an outbreak of dengue fever on Easter Island. The virus was isolated in tissue culture and characterized by reverse transcription–polymerase chain reaction as being dengue type 1. PMID:14718094

  17. Virus-specific T lymphocytes home to the skin during natural dengue infection.

    Science.gov (United States)

    Rivino, Laura; Kumaran, Emmanuelle A; Thein, Tun-Linn; Too, Chien Tei; Gan, Victor Chih Hao; Hanson, Brendon J; Wilder-Smith, Annelies; Bertoletti, Antonio; Gascoigne, Nicholas R J; Lye, David Chien; Leo, Yee Sin; Akbar, Arne N; Kemeny, David M; MacAry, Paul A

    2015-03-11

    Dengue, which is the most prevalent mosquito-borne viral disease afflicting human populations, causes a spectrum of clinical symptoms that include fever, muscle and joint pain, maculopapular skin rash, and hemorrhagic manifestations. Patients infected with dengue develop a broad antigen-specific T lymphocyte response, but the phenotype and functional properties of these cells are only partially understood. We show that natural infection induces dengue-specific CD8(+) T lymphocytes that are highly activated and proliferating, exhibit antiviral effector functions, and express CXCR3, CCR5, and the skin-homing marker cutaneous lymphocyte-associated antigen (CLA). In the same patients, bystander human cytomegalovirus -specific CD8(+) T cells are also activated during acute dengue infection but do not express the same tissue-homing phenotype. We show that CLA expression by circulating dengue-specific CD4(+) and CD8(+) T cells correlates with their in vivo ability to traffic to the skin during dengue infection. The juxtaposition of dengue-specific T cells with virus-permissive cell types at sites of possible dengue exposure represents a previously uncharacterized form of immune surveillance for this virus. These findings suggest that vaccination strategies may need to induce dengue-specific T cells with similar homing properties to provide durable protection against dengue viruses.

  18. Dengue

    Science.gov (United States)

    Dengue is an infection caused by a virus. You can get it if an infected mosquito bites you. Dengue does not spread from person to person. It ... the world. Outbreaks occur in the rainy season. Dengue is rare in the United States. Symptoms include ...

  19. Detection of Mayaro virus infections during a dengue outbreak in Mato Grosso, Brazil.

    Science.gov (United States)

    Vieira, Carla Julia da Silva Pessoa; Silva, David José Ferreira da; Barreto, Eriana Serpa; Siqueira, Carlos Eduardo Hassegawa; Colombo, Tatiana Elias; Ozanic, Katia; Schmidt, Diane Johnson; Drumond, Betânia Paiva; Mondini, Adriano; Nogueira, Maurício Lacerda; Bronzoni, Roberta Vieira de Morais

    2015-07-01

    Arboviruses are common agents of human febrile illness worldwide. In dengue-endemic areas illness due to other arboviruses have been misdiagnosed as dengue based only on clinical-epidemiological data. In this study we investigated the presence of Brazilian arboviruses in sera of 200 patients presenting acute febrile illness, during a dengue outbreak in Sinop, MT, Brazil. The results showed that 38 samples were positive to Dengue virus (DENV) type 1, two samples to DENV type 4, and six to Mayaro virus. These results indicate that arboviruses others than DENV are circulating in Sinop and the surrounding region, which are going undiagnosed. In addition, molecular and evolutionary analyses indicate that two MAYV genotypes are co-circulating in Mato Grosso, Brazil. Thus, a strong surveillance program must be implemented to evaluate and monitor the distribution and the true importance of non-dengue arboviruses in the etiology of acute febrile illnesses.

  20. Clinical, epidemiological and virological features of dengue virus infections in vietnamese patients presenting to primary care facilities with acute undifferentiated fever

    NARCIS (Netherlands)

    K.T.D. Thai; H.L. Phuong; T.T.T. Nga; P.T. Giao; L.Q. Hung; N.V. Nam; T.Q. Binh; C. Simmons; J. Farrar; T.T. Hien; H.R. van Doorn; M.D. de Jong; P.J. de Vries

    2010-01-01

    Objectives: To explore clinical and virological characteristics and describe the epidemiology of dengue in patients who presented with acute undifferentiated fever (AUF) at primary health centers (PHC) in Binh Thuan Province, Vietnam. Methods: A prospective observational study was conducted from 200

  1. Imunocompetent Mice Model for Dengue Virus Infection

    Directory of Open Access Journals (Sweden)

    Denise Gonçalves

    2012-01-01

    Full Text Available Dengue fever is a noncontagious infectious disease caused by dengue virus (DENV. DENV belongs to the family Flaviviridae, genus Flavivirus, and is classified into four antigenically distinct serotypes: DENV-1, DENV-2, DENV-3, and DENV-4. The number of nations and people affected has increased steadily and today is considered the most widely spread arbovirus (arthropod-borne viral disease in the world. The absence of an appropriate animal model for studying the disease has hindered the understanding of dengue pathogenesis. In our study, we have found that immunocompetent C57BL/6 mice infected intraperitoneally with DENV-1 presented some signs of dengue disease such as thrombocytopenia, spleen hemorrhage, liver damage, and increase in production of IFNγ and TNFα cytokines. Moreover, the animals became viremic and the virus was detected in several organs by real-time RT-PCR. Thus, this animal model could be used to study mechanism of dengue virus infection, to test antiviral drugs, as well as to evaluate candidate vaccines.

  2. Dengue Virus Genome Uncoating Requires Ubiquitination

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    Laura A. Byk

    2016-06-01

    Full Text Available The process of genome release or uncoating after viral entry is one of the least-studied steps in the flavivirus life cycle. Flaviviruses are mainly arthropod-borne viruses, including emerging and reemerging pathogens such as dengue, Zika, and West Nile viruses. Currently, dengue virus is one of the most significant human viral pathogens transmitted by mosquitoes and is responsible for about 390 million infections every year around the world. Here, we examined for the first time molecular aspects of dengue virus genome uncoating. We followed the fate of the capsid protein and RNA genome early during infection and found that capsid is degraded after viral internalization by the host ubiquitin-proteasome system. However, proteasome activity and capsid degradation were not necessary to free the genome for initial viral translation. Unexpectedly, genome uncoating was blocked by inhibiting ubiquitination. Using different assays to bypass entry and evaluate the first rounds of viral translation, a narrow window of time during infection that requires ubiquitination but not proteasome activity was identified. In this regard, ubiquitin E1-activating enzyme inhibition was sufficient to stabilize the incoming viral genome in the cytoplasm of infected cells, causing its retention in either endosomes or nucleocapsids. Our data support a model in which dengue virus genome uncoating requires a nondegradative ubiquitination step, providing new insights into this crucial but understudied viral process.

  3. Generation of Anti-platelet Autoantibody During Dengue Virus Infection

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    Huan-Yao Lei

    2008-01-01

    Full Text Available Dengue virus infection causes dengue fever, Dengue Hemorrhagic Fever (DHF and Dengue Shock Syndrome (DSS. Thrombocytopenia is common in dengue fever and is always found in DHF/DSS. The pathogenesis of thrombocytopenia is poorly understood. To further understand the relationship between anti-dengue virus antibody and anti-platelet antibody, we generated monoclonal anti-dengue virus antibodies from the dengue virus infected mice that developed transient thrombocytopenia post dengue infection. The analysis of a panel of monoclonal anti-NS-1 antibodies reveals three different patterns of platelet binding: strong, intermediate, or dull. Their isotypes are different, some are IgM while others are IgG1. Most of anti-platelet antibodies are cross-reactive with NS-1 of dengue virus and can be competitively inhibited by recombinant NS-1 protein, suggesting a molecular mimicry between dengue virus NS-1 protein and platelet. A clone, 13-F4-G5, preferentially bound activated platelets, can recognize two or three proteins around 150 kD on platelets. The binding to platelet would lyse the platelet in the presence of complement or enhance the ADP-induced platelet aggregation. Furthermore, some of these monoclonal antibodies would also react with the cellular antigens of BHK. Based on the data, we conclude that dengue virus infection induces auto anti-platelet antibodies which thereafter may involve in the manifestation of thrombocytopenia. A molecular mimicry between NS-1 and platelet is demonstrated.

  4. Immature Dengue Virus : A Veiled Pathogen?

    NARCIS (Netherlands)

    Rodenhuis-Zybert, Izabela A.; van der Schaar, Hilde M.; Da Silva-Voorham, Júlia; van der Ende-Metselaar, Heidi; Lei, Huan-Yao; Wilschut, Jan; Smit, Jolanda M.

    2010-01-01

    Cells infected with dengue virus release a high proportion of immature prM-containing virions. In accordance, substantial levels of prM antibodies are found in sera of infected humans. Furthermore, it has been recently described that the rates of prM antibody responses are significantly higher in pa

  5. Complete nucleotide sequence analysis of a Dengue-1 virus isolated on Easter Island, Chile.

    Science.gov (United States)

    Cáceres, C; Yung, V; Araya, P; Tognarelli, J; Villagra, E; Vera, L; Fernández, J

    2008-01-01

    Dengue-1 viruses responsible for the dengue fever outbreak in Easter Island in 2002 were isolated from acute-phase sera of dengue fever patients. In order to analyze the complete genome sequence, we designed primers to amplify contiguous segments across the entire sequence of the viral genome. RT-PCR products obtained were cloned, and complete nucleotide and deduced amino acid sequences were determined. This report constitutes the first complete genetic characterization of a DENV-1 isolate from Chile. Phylogenetic analysis shows that an Easter Island isolate is most closely related to Pacific DENV-1 genotype IV viruses.

  6. Immature dengue virus: a veiled pathogen?

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    Izabela A Rodenhuis-Zybert

    2010-01-01

    Full Text Available Cells infected with dengue virus release a high proportion of immature prM-containing virions. In accordance, substantial levels of prM antibodies are found in sera of infected humans. Furthermore, it has been recently described that the rates of prM antibody responses are significantly higher in patients with secondary infection compared to those with primary infection. This suggests that immature dengue virus may play a role in disease pathogenesis. Interestingly, however, numerous functional studies have revealed that immature particles lack the ability to infect cells. In this report, we show that fully immature dengue particles become highly infectious upon interaction with prM antibodies. We demonstrate that prM antibodies facilitate efficient binding and cell entry of immature particles into Fc-receptor-expressing cells. In addition, enzymatic activity of furin is critical to render the internalized immature virus infectious. Together, these data suggest that during a secondary infection or primary infection of infants born to dengue-immune mothers, immature particles have the potential to be highly infectious and hence may contribute to the development of severe disease.

  7. Circulation of Dengue virus-1 (DENV-1 serotype in Delhi, during 2010–11 after Dengue virus-3 (DENV-3 predominance: A single centre hospital-based study

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    Ekta Gupta , Sweta Mohan , Meenu Bajpai , Aashish Choudhary & Gaurav Singh

    2012-06-01

    Full Text Available Background: Delhi, a city in north India, has so far witnessed several reported outbreaks of dengue. Dengue inDelhi from being epidemic is slowly changing towards being endemic and hyper-endemic. Circulating type ofthe virus is also changing over the years. In the absence of an effective vaccine, dengue prevention to a majorextent relies on virological surveillance, and development of effective, locally adapted control programmes. Inthe present study, we tried to identify the between-year non-epidemic serotype of dengue virus circulating inDelhi, during 2010–11.Methods: Acute-phase samples were collected from the patients attending the Institute of Liver & Biliary Sciences,New Delhi, India. Dengue diagnosis was done using WHO case definitions. All the samples were subjected toDengue NS1 Ag ELISA and modified nested RT-PCR.Results: A total of 75 acute-phase samples were received, of which 19 (25.3% were positive for dengue NS1antigen. Dengue RT-PCR was positive in 14.6% (11/75 samples. All the RT-PCR isolates were of DENV-1serotype. No case of concomitant infection with more than one serotype was observed. Median age of involvementwas 23 yr (range10–86. Maximum number of cases were seen in the age group of 21–30 yr. Male to female ratiowas 1.2 : 1. Maximum number of suspected dengue cases (n=79 was seen during September and October.Conclusions: DENV-1 was circulating in Delhi in the year 2010–11 in non-epidemic period following reportedpredominance of DENV-3 and co-circulation of all dengue serotypes in the epidemic years 2003, 2006 and 2007.

  8. Asymptomatic humans transmit dengue virus to mosquitoes.

    Science.gov (United States)

    Duong, Veasna; Lambrechts, Louis; Paul, Richard E; Ly, Sowath; Lay, Rath Srey; Long, Kanya C; Huy, Rekol; Tarantola, Arnaud; Scott, Thomas W; Sakuntabhai, Anavaj; Buchy, Philippe

    2015-11-24

    Three-quarters of the estimated 390 million dengue virus (DENV) infections each year are clinically inapparent. People with inapparent dengue virus infections are generally considered dead-end hosts for transmission because they do not reach sufficiently high viremia levels to infect mosquitoes. Here, we show that, despite their lower average level of viremia, asymptomatic people can be infectious to mosquitoes. Moreover, at a given level of viremia, DENV-infected people with no detectable symptoms or before the onset of symptoms are significantly more infectious to mosquitoes than people with symptomatic infections. Because DENV viremic people without clinical symptoms may be exposed to more mosquitoes through their undisrupted daily routines than sick people and represent the bulk of DENV infections, our data indicate that they have the potential to contribute significantly more to virus transmission to mosquitoes than previously recognized.

  9. Dengue virus serotype in Aceh Province

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    Paisal

    2015-06-01

    Full Text Available WHO estimated 50 million dengue infections happen every year in the world. In Indonesia, there were 90,245 DHF cases on 2012 with 816 deaths. In the Province of Aceh, 2,269 cases happened in the same year. This study aimed to identify dengue virus serotype in Aceh. Sampling was done in Kota Banda Aceh Hospital, Kota Lhokseumawe Hospital, Kabupaten Aceh Tamiang Hospital, Kabupaten Aceh Barat Hospital, and Kabupaten Simeulue Hospital between May to December 2012. This was a clinical laboratory research with observation design using cross sectional approach. Research’s population was sample from patients with dengue clinical symptom. Using purposive sampling technique, we have collected 100 samples from the five hospitals (20 samples from each hospital. From RT-PCR, we found 16 positive samples (9 samples were DENV-4, 3 samples were DENV-1, 2 samples were DENV-2, and 2 samples were DENV-3.

  10. Paediatric Dengue Fever diagnosed through parents' epidemiologic report and preventive strategy during the acute phase of infection.

    Science.gov (United States)

    Poddighe, Dimitri; Bonomelli, Irene; Giardinetti, Silvia; Nedbal, Marco; Bruni, Paola

    2016-01-01

    In Europe, Dengue Fever is one of the most frequent imported diseases and also autochthonous cases occurred in areas where the insect vector is present. Here, we describe a child returning from Philippines and diagnosed with Dengue Fever, through the information provided by parents about an ongoing outbreak in their municipality. An appropriate clinical management in the hospital was established to monitor the occurrence of complications and to cancel the risk of dengue virus transmission in the acute phase of infection.

  11. Immunoglobulin G antibody response in children and adults with acute dengue 3 infection.

    Science.gov (United States)

    Vazquez, Susana; Acosta, Nadia; Ruiz, Didye; Calzada, Naifi; Alvarez, Angel M; Guzman, Maria G

    2009-07-01

    Using a serological test, different criteria have been established for classifying a case as primary or secondary dengue virus infection. Considering the dengue epidemiological situation in Cuba, IgG antibody response to dengue virus infection in serum samples from children and adults with a dengue 3 infection, in Havana city during the 2001-2002 epidemic was evaluated. Samples were collected on days 5-7 of fever onset and tested by an ELISA inhibition. A total of 713 serum samples positive for IgM antibody, 93 from children and 620 from adult patients were studied. Serum samples collected from healthy blood donors and patients not infected with dengue were included as controls. An IgG primary infection pattern was observed in sera collected from children, with titers of or =1280 (83.9%), respectively. These results permitted the definition of a primary or secondary case of dengue virus infection in serum samples collected during the acute phase of dengue virus infection.

  12. Dengue virus type 3, South Pacific Islands, 2013.

    Science.gov (United States)

    Cao-Lormeau, Van-Mai; Roche, Claudine; Musso, Didier; Mallet, Henri-Pierre; Dalipanda, Tenneth; Dofai, Alfred; Nogareda, Francisco; Nilles, Eric J; Aaskov, John

    2014-06-01

    After an 18-year absence, dengue virus serotype 3 reemerged in the South Pacific Islands in 2013. Outbreaks in western (Solomon Islands) and eastern (French Polynesia) regions were caused by different genotypes. This finding suggested that immunity against dengue virus serotype, rather than virus genotype, was the principal determinant of reemergence.

  13. Immune Activation in the Pathogenesis of Dengue Virus Infection

    NARCIS (Netherlands)

    C.A.M. van de Weg (Cornelia A.M.)

    2014-01-01

    markdownabstract__Abstract__ Dengue virus (DENV) is a positive-stranded RNA virus and belongs to the Flaviviridae family. The virus is transmitted by the bite of an infected Aedes-mosquito and circulates in tropical and subtropical areas around the world. The incidence of dengue has risen dramatica

  14. Reemergence and Autochthonous Transmission of Dengue Virus, Eastern China, 2014.

    Science.gov (United States)

    Wang, Wen; Yu, Bin; Lin, Xian-Dan; Kong, De-Guang; Wang, Jian; Tian, Jun-Hua; Li, Ming-Hui; Holmes, Edward C; Zhang, Yong-Zhen

    2015-09-01

    In 2014, 20 dengue cases were reported in the cities of Wenzhou (5 cases) and Wuhan (15 cases), China, where dengue has rarely been reported. Dengue virus 1 was detected in 4 patients. Although most of these cases were likely imported, epidemiologic analysis provided evidence for autochthonous transmission.

  15. Concurrent infections by all four dengue virus serotypes during an outbreak of dengue in 2006 in Delhi, India

    OpenAIRE

    Guleria Randeep; Dar Lalit; Diddi Kavita; Pandey Anubhav; Chahar Harendra S; Bharaj Preeti; Kabra Sushil K; Broor Shobha

    2008-01-01

    Abstract Background Co-circulation of multiple dengue virus serotypes has been reported from many parts of the world including India, however concurrent infection with more than one serotype of dengue viruses in the same individual is rarely documented. An outbreak of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) occurred in and around Delhi in 2006. This is the first report from India with high percentage of concurrent infections with different dengue virus serotypes circulating d...

  16. Seroprevalence of dengue virus in a tertiary care hospital, Andhra Pradesh, South India

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    Srinivas Rao M.S.

    2013-08-01

    Full Text Available Background: Dengue fever and Dengue Haemorrhagic fever (DF/DHF is an acute viral disease caused by Dengue virus. The infection is transmitted by the bite of an infected female mosquito- Aedes aegypti. The Dengue virus causes significant morbidity and mortality in many parts of the world, including India, where it was first isolated in Calcutta, West Bengal during 1945. This study was conducted to know the seroprevalence of Dengue virus in a tertiary care hospital, Hyderabad Methods: Blood for serological studies are carefully collected taking due universal precautions from suspected DF/DHF cases (a as soon as possible after hospital admission or attendance. All the patients were screened for anti-Dengue IgG and IgM antibodies By Enzyme Immunoassay. The study period was 18 months from 2012. Results: From a total of 1327serum samples tested were screened for Dengue IgM and IgG among which 706(53.2% were positive. 125(17.7% were only IgM positive and 198(28.05% of the tested samples showed only IgG positive. 383(54.25% of the tested samples revealed positive for both IgM and IgG antibodies. Conclusion: Surveillance is prerequisite for monitoring the dengue situation in the area and should be carried out regularly for early detection of an impending outbreak and to initiate timely preventive and control measures. [Int J Res Med Sci 2013; 1(4.000: 448-450

  17. Mouse models of dengue virus infection for vaccine testing.

    Science.gov (United States)

    Sarathy, Vanessa V; Milligan, Gregg N; Bourne, Nigel; Barrett, Alan D T

    2015-12-10

    Dengue is a mosquito-borne disease caused by four serologically and genetically related viruses termed DENV-1 to DENV-4. With an annual global burden of approximately 390 million infections occurring in the tropics and subtropics worldwide, an effective vaccine to combat dengue is urgently needed. Historically, a major impediment to dengue research has been development of a suitable small animal infection model that mimics the features of human illness in the absence of neurologic disease that was the hallmark of earlier mouse models. Recent advances in immunocompromised murine infection models have resulted in development of lethal DENV-2, DENV-3 and DENV-4 models in AG129 mice that are deficient in both the interferon-α/β receptor (IFN-α/β R) and the interferon-γ receptor (IFN-γR). These models mimic many hallmark features of dengue disease in humans, such as viremia, thrombocytopenia, vascular leakage, and cytokine storm. Importantly AG129 mice develop lethal, acute, disseminated infection with systemic viral loads, which is characteristic of typical dengue illness. Infected AG129 mice generate an antibody response to DENV, and antibody-dependent enhancement (ADE) models have been established by both passive and maternal transfer of DENV-immune sera. Several steps have been taken to refine DENV mouse models. Viruses generated by peripheral in vivo passages incur substitutions that provide a virulent phenotype using smaller inocula. Because IFN signaling has a major role in immunity to DENV, mice that generate a cellular immune response are desired, but striking the balance between susceptibility to DENV and intact immunity is complicated. Great strides have been made using single-deficient IFN-α/βR mice for DENV-2 infection, and conditional knockdowns may offer additional approaches to provide a panoramic view that includes viral virulence and host immunity. Ultimately, the DENV AG129 mouse models result in reproducible lethality and offer multiple

  18. Emergence of Epidemic Dengue-1 Virus in the Southern Province of Sri Lanka

    Science.gov (United States)

    Nagahawatte, Ajith; Devasiri, Vasantha; Kodikara Arachichi, Wasantha; Strouse, John J.; Sessions, October M.; Kurukulasooriya, Ruvini; Uehara, Anna; Howe, Shiqin; Ong, Xin Mei; Tan, Sharon; Chow, Angelia; Tummalapalli, Praveen; De Silva, Aruna D.; Østbye, Truls; Woods, Christopher W.; Gubler, Duane J.; Reller, Megan E.

    2016-01-01

    Background Dengue is a frequent cause of acute febrile illness with an expanding global distribution. Since the 1960s, dengue in Sri Lanka has been documented primarily along the heavily urbanized western coast with periodic shifting of serotypes. Outbreaks from 2005–2008 were attributed to a new clade of DENV-3 and more recently to a newly introduced genotype of DENV-1. In 2007, we conducted etiologic surveillance of acute febrile illness in the Southern Province and confirmed dengue in only 6.3% of febrile patients, with no cases of DENV-1 identified. To re-evaluate the importance of dengue as an etiology of acute febrile illness in this region, we renewed fever surveillance in the Southern Province to newly identify and characterize dengue. Methodology/Principal Findings A cross-sectional surveillance study was conducted at the largest tertiary care hospital in the Southern Province from 2012–2013. A total of 976 patients hospitalized with acute undifferentiated fever were enrolled, with 64.3% male and 31.4% children. Convalescent blood samples were collected from 877 (89.6%). Dengue virus isolation, dengue RT-PCR, and paired IgG ELISA were performed. Acute dengue was confirmed as the etiology for 388 (39.8%) of 976 hospitalizations, with most cases (291, 75.0%) confirmed virologically and by multiple methods. Among 351 cases of virologically confirmed dengue, 320 (91.2%) were due to DENV-1. Acute dengue was associated with self-reported rural residence, travel, and months having greatest rainfall. Sequencing of selected dengue viruses revealed that sequences were most closely related to those described from China and Southeast Asia, not nearby India. Conclusions/Significance We describe the first epidemic of DENV-1 in the Southern Province of Sri Lanka in a population known to be susceptible to this serotype because of prior study. Dengue accounted for 40% of acute febrile illnesses in the current study. The emergence of DENV-1 as the foremost serotype in

  19. Dengue virus serotype 2 from a sylvatic lineage isolated from a patient with dengue hemorrhagic fever.

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    Jane Cardosa

    Full Text Available Dengue viruses circulate in both human and sylvatic cycles. Although dengue viruses (DENV infecting humans can cause major epidemics and severe disease, relatively little is known about the epidemiology and etiology of sylvatic dengue viruses. A 20-year-old male developed dengue hemorrhagic fever (DHF with thrombocytopenia (12,000/ul and a raised hematocrit (29.5% above baseline in January 2008 in Malaysia. Dengue virus serotype 2 was isolated from his blood on day 4 of fever. A phylogenetic analysis of the complete genome sequence revealed that this virus was a member of a sylvatic lineage of DENV-2 and most closely related to a virus isolated from a sentinel monkey in Malaysia in 1970. This is the first identification of a sylvatic DENV circulating in Asia since 1975.

  20. The cellular bases of antibody responses during dengue virus infection

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    Juan Carlos Yam-Puc

    2016-06-01

    Full Text Available Dengue virus (DENV is one of the most significant human viral pathogens transmitted by mosquitoes and can cause from an asymptomatic disease to mild undifferentiated fever, classical dengue, and severe dengue. Neutralizing memory antibody (Ab responses are one of the most important mechanisms that counteract reinfections and are therefore the main aim of vaccination. However, it has also been proposed that in dengue, some of these class-switched (IgG memory Abs might worsen the disease. Although these memory Abs derive from B cells by T-cell dependent processes, we know rather little about the (acute, chronic or memory B cell responses and the complex cellular mechanisms generating these Abs during DENV infections.This review aims to provide an updated and comprehensive perspective of the B cell responses during DENV infection, starting since the very early events like the cutaneous DENV entrance and the arrival into draining lymph nodes, to the putative B cell activation, proliferation and germinal centers (GCs formation (the source of affinity-matured class-switched memory Abs, till the outcome of GC reactions such as the generation of plasmablasts, Ab-secreting plasma cells and memory B cells. We discuss topics very poorly explored such as the possibility of B cell infection by DENV or even activation-induced B cell death. The current information about the nature of the Ab responses to DENV is also illustrated.

  1. The Medicinal Chemistry of Dengue Virus.

    Science.gov (United States)

    Behnam, Mira A M; Nitsche, Christoph; Boldescu, Veaceslav; Klein, Christian D

    2016-06-23

    The dengue virus and related flaviviruses are an increasing global health threat. In this perspective, we comment on and review medicinal chemistry efforts aimed at the prevention or treatment of dengue infections. We include target-based approaches aimed at viral or host factors and results from phenotypic screenings in cellular assay systems for viral replication. This perspective is limited to the discussion of results that provide explicit chemistry or structure-activity relationship (SAR), or appear to be of particular interest to the medicinal chemist for other reasons. The discovery and development efforts discussed here may at least partially be extrapolated toward other emerging flaviviral infections, such as West Nile virus. Therefore, this perspective, although not aimed at flaviviruses in general, should also be able to provide an overview of the medicinal chemistry of these closely related infectious agents.

  2. Infectious dengue vesicles derived from CD61+ cells in acute patient plasma exhibited a diaphanous appearance.

    Science.gov (United States)

    Hsu, Alan Yi-Hui; Wu, Shang-Rung; Tsai, Jih-Jin; Chen, Po-Lin; Chen, Ya-Ping; Chen, Tsai-Yun; Lo, Yu-Chih; Ho, Tzu-Chuan; Lee, Meed; Chen, Min-Ting; Chiu, Yen-Chi; Perng, Guey Chuen

    2015-12-11

    The levels of neutralizing antibody to a pathogen are an effective indicator to predict efficacy of a vaccine in trial. And yet not all the trial vaccines are in line with the theory. Using dengue virus (DENV) to investigate the viral morphology affecting the predictive value, we evaluated the viral morphology in acute dengue plasma compared to that of Vero cells derived DENV. The virions in plasma were infectious and heterogeneous in shape with a "sunny-side up egg" appearance, viral RNA was enclosed with CD61+ cell-derived membrane interspersed by the viral envelope protein, defined as dengue vesicles. The unique viral features were also observed from ex vivo infected human bone marrow. Dengue vesicles were less efficiently neutralized by convalescent patient serum, compared to virions produced from Vero cells. Our results exhibit a reason why potencies of protective immunity fail in vivo and significantly impact dengue vaccine and drug development.

  3. Dengue fever presenting as acute liver failure- a case report

    Institute of Scientific and Technical Information of China (English)

    Rajat Jhamb; Bineeta Kashyap; Ranga GS; Kumar A

    2011-01-01

    Dengue fever(DF) and dengue haemorrhagic fever(DHF) are important mosquito-borne viral diseases of humans and recognized as important emerging infectious diseases in the tropics and subtropics. Compared to nine reporting countries in the 1950s, today the geographic distribution includes more than100 countries worldwide. Dengue viral infections are known to present a diverse clinical spectrum, ranging from asymptomatic illness to fatal dengue shock syndrome. Mild hepatic dysfunction in dengue haemorrhagic fever is usual. However, its presentation as acute liver failure(ALF)is unusual. We report a patient with dengue shock syndrome who presented with acute liver failure and hepatic encephalopathy in a recent outbreak of dengue fever in Delhi, India.

  4. Acute Renal Failure in Dengue Infection

    Science.gov (United States)

    Subramanyam, Nambakam Tanuja

    2017-01-01

    Introduction Acute Renal Failure (RF) is a rare but well recognized complication of Dengue Infection (DI). There has been paucity of published data regarding renal involvement in DI. Aim The aim of the present study was to elucidate different clinical presentations, disease outcomes of DI. To study the frequency, severity and predictors of RF in DI. Materials and Methods Patients diagnosed either as Dengue Fever (DF) or Dengue Haemorrhagic Fever/Dengue Shock Syndrome (DHF/DSS) respectively were enrolled for this study. The diagnostic criteria for DI were febrile illness associated with one of the following: 1) detection of dengue-specific IgM capture antibody or Non-Structural Protein1 (NS1) antigen; or 2) a four-fold or greater increase of dengue-specific IgG capture antibody by ELISA and haemoagglutination inhibition assay. Patients were diagnosed as having Acute RF, if serum creatinine was >1.2 mg/dl or who showed improvement by 50% in serum creatinine from the initial value. It is an observational study of medical charts, data of age, gender, and medical history of any underlying diseases in association with the severity of DI of each patient recorded. All of the laboratory results were collected. Parameters that influenced the clinical presentations and outcomes for development of classical DF or DHF/DSS in patients with or without RF were analysed and compared. Descriptive and inferential statistical analysis was carried. The Statistical software namely SAS 9.2, SPSS 15.0, Stata 10.1, Med Calc 9.0.1, Systat 12.0 and R environment ver.2.11.1 were used. Results Most common symptoms were fever followed by headache and pain in abdomen. Among the patients with RF, all patients had recovery. The patients with DHF/DSS were more susceptible to develop renal failure compared to DF group. There were statistically significant higher frequencies of renal failure, haemoconcentration, thrombocytopenia, low serum cholesterol. Patients in the RF group also had significantly

  5. Acute bee paralysis virus [

    Lifescience Database Archive (English)

    Full Text Available Acute bee paralysis virus [gbvrl]: 14 CDS's (15780 codons) fields: [triplet] [frequ...osomal protein / MAP kinase List of codon usage for each CDS (format) Homepage Acute bee paralysis virus ...

  6. Antiviral activity of lanatoside C against dengue virus infection.

    Science.gov (United States)

    Cheung, Yan Yi; Chen, Karen Caiyun; Chen, Huixin; Seng, Eng Khuan; Chu, Justin Jang Hann

    2014-11-01

    Dengue infection poses a serious threat globally due to its recent rapid spread and rise in incidence. Currently, there is no approved vaccine or effective antiviral drug for dengue virus infection. In response to the urgent need for the development of an effective antiviral for dengue virus, the US Drug Collection library was screened in this study to identify compounds with anti-dengue activities. Lanatoside C, an FDA approved cardiac glycoside was identified as a candidate anti-dengue compound. Our data revealed that lanatoside C has an IC50 of 0.19μM for dengue virus infection in HuH-7 cells. Dose-dependent reduction in dengue viral RNA and viral proteins synthesis were also observed upon treatment with increasing concentrations of lanatoside C. Time of addition study indicated that lanatoside C inhibits the early processes of the dengue virus replication cycle. Furthermore, lanatoside C can effectively inhibit all four serotypes of dengue virus, flavivirus Kunjin, alphavirus Chikungunya and Sindbis virus as well as the human enterovirus 71. These findings suggest that lanatoside C possesses broad spectrum antiviral activity against several groups of positive-sense RNA viruses.

  7. IL-18 and IL-18 binding protein levels in patients with dengue virus infection

    Institute of Scientific and Technical Information of China (English)

    Chintana Chirathaworn; Yong Poovorawan; Viboonsak Vuthitanachot

    2010-01-01

    Objective:To determine the levels ofIL-18 andIL-18binding protein(BP) in patients with dengue virus infection.Methods: Acute and convalescent sera were collected from each patient. Control group was sera from blood donors. The levels of both IL-18 andIL-18BP were measured byELISA assays.Results: It was shown thatIL-18 andIL-18BPlevels were significantly higher in patients when compared with controls. In addition, the level ofIL-18BP was lower in convalescent than in acute sera.Conclusions: These data suggest that bothIL-18 andIL-18BP production was induced following dengue virus infection. Investigating the regulation of IL-18 by its natural regulator could lead to further understanding of the immune response or immunopathogenesis following dengue virus infection.

  8. Dengue virus and dengue fever%登革病毒和登革热

    Institute of Scientific and Technical Information of China (English)

    崔晓云; 吴艳花; 安静

    2014-01-01

    Dengue fever(DF) is the most widespread mosquito-borne diseases worldwide, caused by Dengue virus(DV). There are nearly half of the world's populations at the risk of infection in tropical and subtropical countries. DF is divided into Dengue and severe Dengue, which include Dengue hemorrhagic fever(DHF) and Dengue shock syndrome(DSS). With an estimated 500 000 cases of life-threatening disease in the form of severe Dengue every year, most of them are children. Notably, there is the most serious DF outbreak in southern China at 2014. This review will summarize several aspects of Dengue virus and Dengue fever to provide the information to the colleagues.%登革热(Dengue fever,DF)是由登革病毒(Dengue virus,DV)引起的一种虫媒传染病,主要在热带亚热带地区流行,全世界将近一半的人口有罹患 DF 的风险。 DF 在临床上分为 DF 和重症登革( severe Dengue),后者包括登革出血热( Dengue hemorrhagic fever,DHF)和登革休克综合征(Dengue shock syndrome,DSS)。每年重症登革病例达500000例,其中大多数患者为儿童。2014年 DF 在我国的南方地区出现历史上最严重的疫情,对人类健康和社会经济造成了严重损失。为此,本文对 DV 和DF 的概况作一综述,供广大同行参考。

  9. Mayaro Virus in Child with Acute Febrile Illness, Haiti, 2015.

    Science.gov (United States)

    Lednicky, John; De Rochars, Valery Madsen Beau; Elbadry, Maha; Loeb, Julia; Telisma, Taina; Chavannes, Sonese; Anilis, Gina; Cella, Eleonora; Ciccozzi, Massinno; Okech, Bernard; Salemi, Marco; Morris, J Glenn

    2016-11-01

    Mayaro virus has been associated with small outbreaks in northern South America. We isolated this virus from a child with acute febrile illness in rural Haiti, confirming its role as a cause of mosquitoborne illness in the Caribbean region. The clinical presentation can mimic that of chikungunya, dengue, and Zika virus infections.

  10. Changing pattern of dengue virus serotypes circulating during 2008-2012 and reappearance of dengue serotype 3 may cause outbreak in Kolkata, India.

    Science.gov (United States)

    Saha, Kallol; Ghosh, Monika; Firdaus, Rushna; Biswas, Aritra; Seth, Bikash; Bhattacharya, Debojyoti; Mukherjee, Kheya; Sadhukhan, Provash Chandra

    2016-10-01

    Dengue virus infection is a major cause of morbidity within the endemic tropical and subtropical regions of the world. Dengue virus has four distinct serotypes with specific clinical manifestations. In this study, we observed the changing pattern of dengue serotypes, age-wise dengue infection and useful sero-detection methods needed in a dengue endemic region. We identified dengue serotypes during a period of 5 years among patients with dengue symptoms visiting one of the largest tertiary care infectious disease hospitals of eastern India in Kolkata. A total of 433 dengue RNA positive samples were isolated from 712 acute dengue suspected cases. Age wise distribution highlighted the susceptible age group being >21 years (24.02%) followed by 11-15 years (21.71%) and 5-10 years (21.02%) of the total infected population. Higher numbers of infected cases were found within females as they are involved in more indoor works. The period of study experienced two dengue outbreaks one in 2008 and another in 2012. For early dengue detection, NS1 was found to be more confirmatory than IgM ELISA regarding sensitivity and specificity. DENV-1, 2, and 4 serotypes were the common circulating strains from 2008 until 2010, after which DENV-3 serotype infections rise and led to a massive dengue outbreak in Kolkata with increased numbers of DHF and DSS cases in 2012. The finding within our study emphasizes the public health importance of such prospective surveillance programs with respect to the changing dengue viral etiology and serotypes. J. Med. Virol. 88:1697-1702, 2016. © 2016 Wiley Periodicals, Inc.

  11. Partial maturation : an immune-evasion strategy of dengue virus?

    NARCIS (Netherlands)

    Rodenhuis-Zybert, Izabela A.; Wilschut, Jan; Smit, Jolanda M.

    2011-01-01

    Cleavage of the precursor membrane (prM) protein is required for the activation of flavivirus infectivity. However, many studies have shown that, for dengue virus in particular, prM cleavage and maturation is inefficient. Heterogeneity of wild-type dengue virus preparations with regard to the presen

  12. Acute viral hemorrhage disease:A summary on new viruses

    Institute of Scientific and Technical Information of China (English)

    Somsri Wiwanitkit; Viroj Wiwanitkit

    2015-01-01

    Acute hemorrhagic disease is an important problem in medicine that can be seen in many countries, especially those in tropical world. There are many causes of acute hemorrhagic disease and the viral infection seems to be the common cause. The well-known infection is dengue, however, there are many new identified viruses that can cause acute hemorrhagic diseases. In this specific short review, the authors present and discuss on those new virus diseases that present as “acute hemorrhagic fever”.

  13. A recombinant, chimeric tetravalent dengue vaccine candidate based on a dengue virus serotype 2 backbone.

    Science.gov (United States)

    Osorio, Jorge E; Wallace, Derek; Stinchcomb, Dan T

    2016-01-01

    Dengue fever is caused by infection with one of four dengue virus (DENV) serotypes (DENV-1-4), necessitating tetravalent dengue vaccines that can induce protection against all four DENV. Takeda's live attenuated tetravalent dengue vaccine candidate (TDV) comprises an attenuated DENV-2 strain plus chimeric viruses containing the prM and E genes of DENV-1, -3 and -4 cloned into the attenuated DENV-2 'backbone'. In Phase 1 and 2 studies, TDV was well tolerated by children and adults aged 1.5-45 years, irrespective of prior dengue exposure; mild injection-site symptoms were the most common adverse events. TDV induced neutralizing antibody responses and seroconversion to all four DENV as well as cross-reactive T cell-mediated responses that may be necessary for broad protection against dengue fever.

  14. Detection of Hepatitis C Virus Coinfection in Patients with Dengue Diagnosis

    Directory of Open Access Journals (Sweden)

    Carlos Machain-Williams

    2014-01-01

    Full Text Available Coinfection produced by dengue virus (DENV and hepatitis C virus (HCV is a serious problem of public health in Mexico, as they both circulate in tropical zones and may lead to masking or complicating symptoms. In this research, we detected active coinfected patients by HCV residing in the endemic city of Mérida, Yucatán, Mexico, with positive diagnosis to dengue during the acute phase. We performed a retrospective analysis of 240 serum samples from dengue patients. The IgM-ELISA serological test was used for dengue diagnosis, as well as viral isolation to confirm infection. DENV and HCV were detected by RT-PCR. Thus, 31 (12.9% samples showed DENV-HCV coinfection, but interestingly the highest frequency of coinfection cases was found in male patients presenting hemorrhagic dengue in 19/31 (61.29%, with a predominance of 12 : 7 in males. Firstly, coinfection of DENV-HCV in Mérida, Mexico, was detected in young dengue patients, between 11 and 20 years old (38.7%, followed by those between 21 and 30 years old (32%; only 16.13% were between 0 and 10 years of age. Diagnosis of HCV infection in patients with dengue is highly recommended in order to establish potential risk in clinical manifestations as well as dictate patients' special care.

  15. Reliable classifier to differentiate primary and secondary acute dengue infection based on IgG ELISA.

    Directory of Open Access Journals (Sweden)

    Marli Tenório Cordeiro

    Full Text Available BACKGROUND: Dengue virus infection causes a wide spectrum of illness, ranging from sub-clinical to severe disease. Severe dengue is associated with sequential viral infections. A strict definition of primary versus secondary dengue infections requires a combination of several tests performed at different stages of the disease, which is not practical. METHODS AND FINDINGS: We developed a simple method to classify dengue infections as primary or secondary based on the levels of dengue-specific IgG. A group of 109 dengue infection patients were classified as having primary or secondary dengue infection on the basis of a strict combination of results from assays of antigen-specific IgM and IgG, isolation of virus and detection of the viral genome by PCR tests performed on multiple samples, collected from each patient over a period of 30 days. The dengue-specific IgG levels of all samples from 59 of the patients were analyzed by linear discriminant analysis (LDA, and one- and two-dimensional classifiers were designed. The one-dimensional classifier was estimated by bolstered resubstitution error estimation to have 75.1% sensitivity and 92.5% specificity. The two-dimensional classifier was designed by taking also into consideration the number of days after the onset of symptoms, with an estimated sensitivity and specificity of 91.64% and 92.46%. The performance of the two-dimensional classifier was validated using an independent test set of standard samples from the remaining 50 patients. The classifications of the independent set of samples determined by the two-dimensional classifiers were further validated by comparing with two other dengue classification methods: hemagglutination inhibition (HI assay and an in-house anti-dengue IgG-capture ELISA method. The decisions made with the two-dimensional classifier were in 100% accordance with the HI assay and 96% with the in-house ELISA. CONCLUSIONS: Once acute dengue infection has been determined, a 2-D

  16. Cloning and application of recombinant dengue virus prM-M protein for serodiagnosis of dengue virus infection.

    Science.gov (United States)

    Wichit, Sineewanlaya; Yongpradoem, Hatairat; Surasombatpattana, Pornapat; Leaungwuttiwong, Pornsawan; Kalambaheti, Thareerat; Jampangern, Wipawee; Jittmittraphap, Akanitt

    2013-03-01

    We studied the use of the precursor to the M structural protein (prM) found only on the surface of mature dengue virus as a target protein to detect dengue virus infection. Recombinant D2-16681 prM-M protein was constructed and tested for immunogenicity with dengue and Japanese encephalitis patient sera by Western blot analysis and indirect ELISA. The sensitivity and specificity of indirect ELISA were 48.1 and 85.5%, respectively, and Western blot assay were 23.1 and 98.7%, respectively, for detection of dengue virus. Although the sensitivity of the indirect ELISA is low, the indirect ELISA using recombinant D2-16681 prM-M proteins as antigen may be used for early detection of dengue virus infection.

  17. Dengue virus type 3 in Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Nogueira Rita Maria R

    2001-01-01

    Full Text Available Dengue virus type 3 was isolated for the first time in the country as an indigenous case from a 40 year-old woman presenting signs and symptoms of a classical dengue fever in the municipality of Nova Iguaçu, State of Rio de Janeiro. This serotype has been associated with dengue haemorrhagic epidemics and the information could be used to implement appropriate prevention and control measures. Virological surveillance was essential in order to detected this new serotype.

  18. Why are dengue virus serotypes so distantly related? Enhancement and limiting serotype similarity between dengue virus strains.

    OpenAIRE

    Kawaguchi, Isao; Sasaki, Akira; Boots, Michael

    2003-01-01

    Dengue virus, the causative agent of dengue fever, has four major serotypes characterized by large genetic and immunological distances. We propose that the unusually large distances between the serotypes can be explained in the light of a process of antibody-dependent enhancement (ADE) leading to increased mortality. Antibody-dependent enhancement results from a new infection with a particular serotype in an individual with acquired immunity to a different serotype. Classical dengue fever cau...

  19. Human skin Langerhans cells are targets of dengue virus infection

    NARCIS (Netherlands)

    Wu, SJL; Grouard-Vogel, G; Mascola, [No Value; Brachtel, E; Putvatana, R; Louder, MK; Filgueira, L; Marovich, MA; Wong, HK; Blauvelt, A; Murphy, GS; Robb, ML; Innes, BL; Birx, DL; Hayes, CG; Frankel, SS

    2000-01-01

    Dengue virus (DV), an arthropod-borne flavivirus, causes a febrile illness for which there is no antiviral treatment and no vaccine(1,2). Macrophages are important in dengue pathogenesis; however, the initial target cell for DV infection remains unknown. As DV is introduced into human skin by mosqui

  20. Breaking barriers : Early events in chikungunya and dengue virus infections

    NARCIS (Netherlands)

    Hoornweg, Tabitha Elina

    2016-01-01

    Breaking Barriers – early events in chikungunya and dengue virus infections Chikungunya en dengue zijn twee door muggen overdraagbare virussen die voornamelijk voorkomen in (sub)tropische gebieden. Sinds 2006 verspreidt het chikungunyavirus zich in een razend tempo over de wereld. Miljoenen mensen r

  1. Molecular characterization of dengue and chikungunya virus strains circulating in New Delhi, India.

    Science.gov (United States)

    Afreen, Nazia; Deeba, Farah; Khan, Wajihul H; Haider, Shakir H; Kazim, Syed Naqui; Ishrat, Romana; Naqvi, Irshad Hussain; Shareef, Mohammad Y; Broor, Shobha; Ahmed, Anwar; Parveen, Shama

    2014-12-01

    Dengue and chikungunya are acute viral infections with overlapping clinical symptoms. Both diseases are transmitted by common mosquito vectors resulting in their co-circulation in a region. Molecular and serological tests specific for both dengue and chikungunya infections were performed on 87 acute phase blood samples collected from patients with suspected dengue/chikungunya infections in Delhi from September to December, 2011. RT-PCR and IgM ELISA were performed to detect dengue virus (DENV) and chikungunya virus (CHIKV). NS1 and IgG ELISA were also performed to detect DENV specific antigen and secondary DENV infection. DENV infection was detected in 49%, CHIKV infection in 29% and co-infection with DENV and CHIKV in 10% of the samples by RT-PCR. DENV serotypes 1, 2 and 3 were detected in this study. Nine DENV-1 strains, six DENV-2 strains and 20 CHIKV strains were characterized by DNA sequencing and phylogenetic analysis of their respective envelope protein genes. DENV-1 strains grouped in the American African genotype, DENV-2 strains in the Cosmopolitan genotype and CHIKV strains in the East Central South African genotype by phylogenetic analysis. This is one of the few studies reporting the phylogeny of two dengue virus serotypes (DENV-1 and DENV-2) and CHIKV. Surveillance and monitoring of DENV and CHIKV strains are important for design of strategies to control impending epidemics.

  2. Prevalence of dengue and chikungunya virus infections in north-eastern Tanzania

    DEFF Research Database (Denmark)

    Kajeguka, Debora C; Kaaya, Robert D; Mwakalinga, Steven

    2016-01-01

    BACKGROUND: In spite of increasing reports of dengue and chikungunya activity in Tanzania, limited research has been done to document the general epidemiology of dengue and chikungunya in the country. This study aimed at determining the sero-prevalence and prevalence of acute infections of dengue...... and chikungunya virus among participants presenting with malaria-like symptoms (fever, headache, rash, vomit, and joint pain) in three communities with distinct ecologies of north-eastern Tanzania. METHODS: Cross sectional studies were conducted among 1100 participants (aged 2-70 years) presenting with malaria......-like symptoms at health facilities at Bondo dispensary (Bondo, Tanga), Hai hospital (Hai, Kilimanjaro) and TPC hospital (Lower Moshi). Participants who were malaria negative using rapid diagnostic tests (mRDT) were screened for sero-positivity towards dengue and chikungunya Immunoglobulin G and M (IgG and Ig...

  3. [Population genetics of dengue virus and transmission of dengue fever].

    Science.gov (United States)

    Falcón-Lezama, Jorge; Sánchez-Burgos, Gilma Guadalupe; Ramos-Castañeda, José

    2009-01-01

    The endemic behavior of dengue fever in Mexico during the past five years is of major concern to every sector related with public health and the effort to control the transmission has been focused on vector control. However, regardless of the effectiveness of the intervention measures it is important to know which elements determine dengue transmission. With regard to the molecular basis for dengue transmission, a great deal of progress has been made due to the introduction of genomic and bioinformatic approaches. The goal of this review is to describe the most recent developments in this area with emphasis on the Mexican situation.

  4. Dengue viruses cluster antigenically but not as discrete serotypes

    NARCIS (Netherlands)

    L. Katzelnick (Leah); J.M. Fonville (Judith); G.D. Gromowski (Gregory D.); J.B. Arriaga (Jose Bustos); A. Green (Angela); S.L. James (Sarah ); L. Lau (Louis); M. Montoya (Magelda); C. Wang (Chunling); L.A. Van Blargan (Laura A.); C.A. Russell (Colin); H.M. Thu (Hlaing Myat); T.C. Pierson (Theodore C.); P. Buchy (Philippe); J.G. Aaskov (John G.); J.L. Muñoz-Jordán (Jorge L.); N. Vasilakis (Nikos); R.V. Gibbons (Robert V.); R.B. Tesh (Robert B.); A.D.M.E. Osterhaus (Albert); R.A.M. Fouchier (Ron); A. Durbin (Anna); C.P. Simmons (Cameron P.); E.C. Holmes (Edward C.); E. Harris (Eva); S.S. Whitehead (Stephen S.); D.J. Smith (Derek James)

    2015-01-01

    textabstractThe four genetically divergent dengue virus (DENV) types are traditionally classified as serotypes. Antigenic and genetic differences among the DENV types influence disease outcome, vaccine-induced protection, epidemic magnitude, and viral evolution.We scharacterized antigenic diversity

  5. Zika Virus, Chikungunya Virus, and Dengue Virus in Cerebrospinal Fluid from Adults with Neurological Manifestations, Guayaquil, Ecuador

    Science.gov (United States)

    Acevedo, Nathalie; Waggoner, Jesse; Rodriguez, Michelle; Rivera, Lissette; Landivar, José; Pinsky, Benjamin; Zambrano, Hector

    2017-01-01

    Zika virus (ZIKV), chikungunya virus (CHIKV), and dengue virus (DENV) have been associated with clinical presentations that involve acute neurological complaints. In the current study, we identified ZIKV, CHIKV, and DENV in cerebrospinal fluid (CSF) samples from patients admitted to the Hospital Luis Vernaza (Guayaquil, Ecuador) to the Emergency Room or the Intensive Care Unit, with neurological symptoms and/or concern for acute arboviral infections. Viral RNA from one or more virus was detected in 12/16 patients. Six patients were diagnosed with meningitis or encephalitis, three with Guillain–Barré Syndrome, and one with CNS vasculitis. Two additional patients had a systemic febrile illness including headache that prompted testing of CSF. Two patients, who were diagnosed with encephalitis and meningoencephalitis, died during their hospitalizations. These cases demonstrate the breadth and significance of neurological manifestations associated with ZIKV, CHIKV, and DENV infections. PMID:28174559

  6. Outbreak of viral hemorrhagic fever caused by dengue virus type 3 in Al-Mukalla, Yemen

    Science.gov (United States)

    2013-01-01

    Background Investigations were conducted by the authors to explore an outbreak of viral hemorrhagic fever (VHF) reported in 2010 from Al-Mukalla city, the capital of Hadramout in Yemen. Methods From 15–17 June 2010, the outbreak investigation period, specimens were obtained within 7 days after onset of illness of 18 acutely ill patients hospitalized with VHF and 15 household asymptomatic contacts of 6 acute cases. Additionally, 189 stored sera taken from acutely ill patients with suspected VHF hospitalized in the preceding 12 months were obtained from the Ministry of Health of Yemen. Thus, a total of 222 human specimens were collected; 207 specimens from acute cases and 15 specimens from contacts. All samples were tested with RT-PCR for dengue (DENV), Alkhumra (ALKV), Rift Valley Fever (RVFV), Yellow Fever (YFV), and Chikungunya (CHIKV) viruses. Samples were also tested for DENV IgM, IgG, and NS1-antigen. Medical records of patients were reviewed and demographic, clinical, and laboratory data was collected. Results Of 207 patients tested, 181 (87.4%) patients were confirmed to have acute dengue with positive dengue NS1-antigen (97 patients, 46.9%) and/or IgM (163 patients, 78.7%). Of the 181 patients with confirmed dengue, 100 (55.2%) patients were IgG-positive. DENV RNA was detected in 2 (1%) patients with acute symptoms; both samples were molecularly typed as DENV type 3. No other VHF viruses were detected. For the 15 contacts tested, RT-PCR tests for the five viruses were negative, one contact was dengue IgM positive, and another one was dengue IgG positive. Of the 181 confirmed dengue patients, 120 (66.3%) patients were males and the median age was 24 years. The most common manifestations included fever (100%), headache (94.5%), backache (93.4%), malaise (88.4%), arthralgia (85.1%), myalgia (82.3%), bone pain (77.9%), and leukopenia (76.2%). Two (1.1%) patients died. Conclusions DENV-3 was confirmed to be the cause of an outbreak of VHF in Al

  7. Innate immunity evasion by Dengue virus.

    Science.gov (United States)

    Morrison, Juliet; Aguirre, Sebastian; Fernandez-Sesma, Ana

    2012-03-01

    For viruses to productively infect their hosts, they must evade or inhibit important elements of the innate immune system, namely the type I interferon (IFN) response, which negatively influences the subsequent development of antigen-specific adaptive immunity against those viruses. Dengue virus (DENV) can inhibit both type I IFN production and signaling in susceptible human cells, including dendritic cells (DCs). The NS2B3 protease complex of DENV functions as an antagonist of type I IFN production, and its proteolytic activity is necessary for this function. DENV also encodes proteins that antagonize type I IFN signaling, including NS2A, NS4A, NS4B and NS5 by targeting different components of this signaling pathway, such as STATs. Importantly, the ability of the NS5 protein to bind and degrade STAT2 contributes to the limited host tropism of DENV to humans and non-human primates. In this review, we will evaluate the contribution of innate immunity evasion by DENV to the pathogenesis and host tropism of this virus.

  8. Dengue Virus Infection Perturbs Lipid Homeostasis in Infected Mosquito Cells

    Energy Technology Data Exchange (ETDEWEB)

    Perera, Rushika M.; Riley, Catherine; Isaac, Georgis; Hopf- Jannasch, Amber; Moore, Ronald J.; Weitz, Karl K.; Pasa-Tolic, Ljiljana; Metz, Thomas O.; Adamec, Jiri; Kuhn, Richard J.

    2012-03-22

    Dengue virus causes {approx}50-100 million infections per year and thus is considered one of the most aggressive arthropod-borne human pathogen worldwide. During its replication, dengue virus induces dramatic alterations in the intracellular membranes of infected cells. This phenomenon is observed both in human and vector-derived cells. Using high-resolution mass spectrometry of mosquito cells, we show that this membrane remodeling is directly linked to a unique lipid repertoire induced by dengue virus infection. Specifically, 15% of the metabolites detected were significantly different between DENV infected and uninfected cells while 85% of the metabolites detected were significantly different in isolated replication complex membranes. Furthermore, we demonstrate that intracellular lipid redistribution induced by the inhibition of fatty acid synthase, the rate-limiting enzyme in lipid biosynthesis, is sufficient for cell survival but is inhibitory to dengue virus replication. Lipids that have the capacity to destabilize and change the curvature of membranes as well as lipids that change the permeability of membranes are enriched in dengue virus infected cells. Several sphingolipids and other bioactive signaling molecules that are involved in controlling membrane fusion, fission, and trafficking as well as molecules that influence cytoskeletal reorganization are also up regulated during dengue infection. These observations shed light on the emerging role of lipids in shaping the membrane and protein environments during viral infections and suggest membrane-organizing principles that may influence virus-induced intracellular membrane architecture.

  9. Chimeric Yellow Fever/Dengue Virus as a Candidate Dengue Vaccine: Quantitation of the Dengue Virus-Specific CD8 T-Cell Response

    OpenAIRE

    van der Most, Robbert G.; Murali-Krishna, Kaja; Ahmed, Rafi; Strauss, James H.

    2000-01-01

    We have constructed a chimeric yellow fever/dengue (YF/DEN) virus, which expresses the premembrane (prM) and envelope (E) genes from DEN type 2 (DEN-2) virus in a YF virus (YFV-17D) genetic background. Immunization of BALB/c mice with this chimeric virus induced a CD8 T-cell response specific for the DEN-2 virus prM and E proteins. This response protected YF/DEN virus-immunized mice against lethal dengue encephalitis. Control mice immunized with the parental YFV-17D were not protected against...

  10. ROLE OF THE SEROLOGIC TEST FOR DENGUE VIRUS INFECTION

    Directory of Open Access Journals (Sweden)

    Ni Luh Sinta Purnama Dewi

    2013-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Dengue virus infection is infection disease cause by dengue virus. Dengue virus infection can cause a broad spectrum disease such as : dengue fever (DF, dengue hemorrhagic fever (DHF, and dengue shock syndrome (DSS. Currently dengue virus ranks eighth as a cause of illness in the State of South-East Asia and Western Pacific. Epidemic dengue hemorrhagic fever (DHF occur each year in Indonesia with a tendency incident and the affected area is increasing. Laboratory tests can be done to detect the dengue virus infection: a complete blood count and serology. Of serology test, positive IgM antibody showed that patients had a primary infection, whereas patients with secondary infections showed positive IgG antibodies, usually accompanied by antibody IgM positive. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  11. Interactions between dengue virus and the host cell

    OpenAIRE

    Mondotte, Juan Alberto

    2011-01-01

    El virus del dengue produce en humanos la enfermedad viral más frecuentemente transmitida por artrópodos y no existe hasta el momento terapia antiviral ni vacuna alguna. En este trabajo se desarrollaron diferentes herramientas genéticas con el fin de estudiar las distintas etapas de la replicación viral y la interacción del virus con la célula huésped. Así, se obtuvo el primer clon infeccioso del virus del dengue de un aislamiento argentino y distintas generaciones de virus con proteínas repo...

  12. Dengue virus binding and replication by platelets.

    Science.gov (United States)

    Simon, Ayo Y; Sutherland, Michael R; Pryzdial, Edward L G

    2015-07-16

    Dengue virus (DENV) infection causes ∼200 million cases of severe flulike illness annually, escalating to life-threatening hemorrhagic fever or shock syndrome in ∼500,000. Although thrombocytopenia is typical of both mild and severe diseases, the mechanism triggering platelet reduction is incompletely understood. As a probable initiating event, direct purified DENV-platelet binding was followed in the current study by quantitative reverse transcription-polymerase chain reaction and confirmed antigenically. Approximately 800 viruses specifically bound per platelet at 37°C. Fewer sites were observed at 25°C, the blood bank storage temperature (∼350 sites), or 4°C, known to attenuate virus cell entry (∼200 sites). Dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) and heparan sulfate proteoglycan were implicated as coreceptors because only the combination of anti-DC-SIGN and low-molecular-weight heparin prevented binding. Interestingly, at 37°C and 25°C, platelets replicated the positive sense single-stranded RNA genome of DENV by up to ∼4-fold over 7 days. Further time course experiments demonstrated production of viral NS1 protein, which is known to be highly antigenic in patient serum. The infectivity of DENV intrinsically decayed in vitro, which was moderated by platelet-mediated generation of viable progeny. This was shown using a transcription inhibitor and confirmed by freeze-denatured platelets being incapable of replicating the DENV genome. For the first time, these data demonstrate that platelets directly bind DENV saturably and produce infectious virus. Thus, expression of antigen encoded by DENV is a novel consideration in the pathogen-induced thrombocytopenia mechanism. These results furthermore draw attention to the possibility that platelets may produce permissive RNA viruses in addition to DENV.

  13. Transovarial Transmission of Dengue Virus on Aedes aegypti (L.

    Directory of Open Access Journals (Sweden)

    Magdalena Desiree Seran

    2012-11-01

    Full Text Available The ability of dengue virus to maintain its existence in nature through two mechanisms, both horizontal and vertical transmission (transovarial of the infective female mosquitoes to the next generation. This study aims to investigate the transovarial transmission and transovarial infection rate (TIR of dengue virus in eggs Aedes aegypti infected mother has a peroral virus DEN-2. This study is an experimental study in the laboratory. The population of the study was Ae. aegypti adults who have previously been infected with DEN-2 virus orally and proved to be infected with DEN-2 transovarially (Fl. The research sample was egg of Ae. aegypti from F2 generation which colonized from DEN-2 transovarially infected Ae. aegypti (Fl. Egg squash preparations made as many as 50 samples from jive difJerent mosquito parents. The presence of dengue virus antigen in mosquitoes FO and Fl were checked by SPBC immunocytochemistry method and using monoclonal antibodies DSSC7 (l:50 as standardized primary antibodies. The results shows the existence of transovarial transmission of dengue virus in eggs Ae. aegypti (F2 were seen in squash preparations in the form of a brownish color egg spread on embryonic tissues (TIR= 52%. It concludes that dengue virus is able to be transmitted vertically through the egg.

  14. Monoclonal Antibodies for Dengue Virus prM Glycoprotein Protect Mice against Lethal Dengue Infection

    Science.gov (United States)

    1989-09-15

    Nile virus and a prelysozomal endosome prM glycoprotein of dengue virus can also be required for viral replication . PrM Mabs 2H2 protective against...tech- bodies can prevent lethal alphavirus encepha- niques to preserve immunogenicity, to deter- litis. Nature 297: 70-72. UI:82173237 mine whether

  15. Evaluation of a Commercial SD Dengue Virus NS1 Antigen Capture Enzyme-Linked Immunosorbent Assay Kit for Early Diagnosis of Dengue Virus Infection▿

    OpenAIRE

    Wang, Seok Mui; Sekaran, Shamala Devi

    2010-01-01

    Early definitive diagnosis of dengue virus infection may help in the timely management of dengue virus infection. We evaluated the Standard Diagnostics (SD, South Korea) dengue virus nonstructural protein NS1 antigen enzyme-linked immunosorbent assay (SD dengue NS1 Ag ELISA) for the detection of dengue virus NS1 antigen in patients' sera, using a total of 399 serum samples in a comparison with real-time reverse transcription (RT)-PCR, an in-house IgM capture (MAC)-ELISA, and a hemagglutinatio...

  16. Evaluation of dengue virus strains for human challenge studies.

    Science.gov (United States)

    Mammen, M P; Lyons, A; Innis, B L; Sun, W; McKinney, D; Chung, R C Y; Eckels, K H; Putnak, R; Kanesa-thasan, N; Scherer, J M; Statler, J; Asher, L V; Thomas, S J; Vaughn, D W

    2014-03-14

    Discordance between the measured levels of dengue virus neutralizing antibody and clinical outcomes in the first-ever efficacy study of a dengue tetravalent vaccine (Lancet, Nov 2012) suggests a need to re-evaluate the process of pre-screening dengue vaccine candidates to better predict clinical benefit prior to large-scale vaccine trials. In the absence of a reliable animal model and established correlates of protection for dengue, a human dengue virus challenge model may provide an approach to down-select vaccine candidates based on their ability to reduce risk of illness following dengue virus challenge. We report here the challenge of flavivirus-naïve adults with cell culture-passaged dengue viruses (DENV) in a controlled setting that resulted in uncomplicated dengue fever (DF). This sets the stage for proof-of-concept efficacy studies that allow the evaluation of dengue vaccine candidates in healthy adult volunteers using qualified DENV challenge strains well before they reach field efficacy trials involving children. Fifteen flavivirus-naïve adult volunteers received 1 of 7 DENV challenge strains (n=12) or placebo (n=3). Of the twelve volunteers who received challenge strains, five (two DENV-1 45AZ5 and three DENV-3 CH53489 cl24/28 recipients) developed DF, prospectively defined as ≥2 typical symptoms, ≥48h of sustained fever (>100.4°F) and concurrent viremia. Based on our study and historical data, we conclude that the DENV-1 and DENV-3 strains can be advanced as human challenge strains. Both of the DENV-2 strains and one DENV-4 strain failed to meet the protocol case definition of DF. The other two DENV-4 strains require additional testing as the illness approximated but did not satisfy the case definition of DF. Three volunteers exhibited effusions (1 pleural/ascites, 2 pericardial) and 1 volunteer exhibited features of dengue (rash, lymphadenopathy, neutropenia and thrombocytopenia), though in the absence of fever and symptoms. The occurrence of

  17. Rapid Subtyping of Dengue Virus Serotypes 1 and 4 by Restriction Site-Specific PCR

    OpenAIRE

    Marize P Miagostovich; dos Santos, Flavia B.; Gutiérrez, C. Milena; Riley, Lee W.; Harris, Eva

    2000-01-01

    We previously reported a simple subtyping method, restriction site-specific PCR (RSS-PCR), for dengue virus serotypes 2 and 3; here we describe its application for subtyping dengue virus serotypes 1 and 4. Three major RSS-PCR types were observed for dengue virus serotype 1 and two types were observed for dengue virus serotype 4, in agreement with previous strain classifications based on sequence analysis. Because of its simplicity, this method is amenable to rapid subtyping and application to...

  18. Recognition determinants of broadly neutralizing human antibodies against dengue viruses.

    Science.gov (United States)

    Rouvinski, Alexander; Guardado-Calvo, Pablo; Barba-Spaeth, Giovanna; Duquerroy, Stéphane; Vaney, Marie-Christine; Kikuti, Carlos M; Navarro Sanchez, M Erika; Dejnirattisai, Wanwisa; Wongwiwat, Wiyada; Haouz, Ahmed; Girard-Blanc, Christine; Petres, Stéphane; Shepard, William E; Desprès, Philippe; Arenzana-Seisdedos, Fernando; Dussart, Philippe; Mongkolsapaya, Juthathip; Screaton, Gavin R; Rey, Félix A

    2015-04-02

    Dengue disease is caused by four different flavivirus serotypes, which infect 390 million people yearly with 25% symptomatic cases and for which no licensed vaccine is available. Recent phase III vaccine trials showed partial protection, and in particular no protection for dengue virus serotype 2 (refs 3, 4). Structural studies so far have characterized only epitopes recognized by serotype-specific human antibodies. We recently isolated human antibodies potently neutralizing all four dengue virus serotypes. Here we describe the X-ray structures of four of these broadly neutralizing antibodies in complex with the envelope glycoprotein E from dengue virus serotype 2, revealing that the recognition determinants are at a serotype-invariant site at the E-dimer interface, including the exposed main chain of the E fusion loop and the two conserved glycan chains. This 'E-dimer-dependent epitope' is also the binding site for the viral glycoprotein prM during virus maturation in the secretory pathway of the infected cell, explaining its conservation across serotypes and highlighting an Achilles' heel of the virus with respect to antibody neutralization. These findings will be instrumental for devising novel immunogens to protect simultaneously against all four serotypes of dengue virus.

  19. Evaluation of a commercial real-time PCR kit for detection of dengue virus in samples collected during an outbreak in Goiania, Central Brazil, in 2005.

    Science.gov (United States)

    Levi, José Eduardo; Tateno, Adriana Fumie; Machado, Adriana Freire; Ramalho, Débora Camillo; de Souza, Vanda Akico Ueda Fick; Guilarde, Adriana Oliveira; de Rezende Feres, Valéria Christina; Martelli, Celina Maria Turchi; Turchi, Marília Dalva; Siqueira, João Bosco; Pannuti, Cláudio Sérgio

    2007-06-01

    In the past 2 decades, dengue has reemerged in Brazil as a significant public health problem. Clinicians demand a diagnostic test with high sensitivity that is applicable during the early symptomatic phase. We aimed to test two distinct molecular methods on samples from suspected dengue cases during an outbreak in Central Brazil. Acute-phase serum specimens from 254 patients suspected of having dengue were collected during 2005 in the city of Goiânia, Central Brazil. Samples were blindly evaluated by real-time and multiplex PCR in addition to routine immunoglobulin M serology and virus culture. Overall, acute dengue was confirmed by serology, multiplex PCR, or virus isolation for 80% of patients (203/254). Another four patients presented real-time PCR-positive results as the unique marker of dengue. Higher real-time PCR positivity levels and viral loads were observed in the early symptomatic phase of disease (< or =5 days) than after this period. Multiplex and real-time PCR assays presented a high kappa agreement (0.85). According to multiplex PCR, 60 samples harbored dengue virus type 3 (DEN-3), 4 samples harbored DEN-2, and 1 sample displayed a pattern compatible with a double infection with DEN-2 and -3. The dengue virus real-time kit was found to be practical and adjustable for high throughput, to display the best performance in the early symptomatic phase of dengue cases, and to be valuable for confirming dengue diagnosis in a timely manner.

  20. PAIgG and PAIgM levels in secondary dengue virus infections lead to thrombocytopenia in patients from KP, Pakistan

    Institute of Scientific and Technical Information of China (English)

    Ibrar Alam; Said Hassan; Iftikhar Alam; Rahmat Gul; Farhad Ali; Ijaz Ali; Sana Ullah; Imtiaz Ali Khan; Aasif Awan

    2015-01-01

    Objective:To understand the impact of platelet associated immunoglobulin G (PAIgG)/ platelet associated immunoglobulin M (PAIgM) on severity of dengue virus infection leading to thrombocytopenia. Methods: In this study we examined a total of 52 patients who were having secondary infection of dengue in acute phase by using competitive ELISA. Results: A decrease in the platelet count was observed at the acute phase of infection while all along the recovery stage the count of platelet was significantly increased. A significant decrease was observed inPAIgG andPAIgM in these subjects. Inverse correlation was found between platelets count andPAIgG/PAIgM among the subjects studied. In the platelets elution from ten subjects, anti-dengue virus immunoglobulin G and immunoglobulin M were observed.PAIgG andPAIgM with inclined levels were higher in dengue hemorrhagic fever than the classical dengue fever. In the development of dengue hemorrhagic feverPAIgM inclined level was independently associated with high specificity, showing a possible indication of dengue hemorrhagic fever. Conclusions: This study suggests that in secondary dengue virus infection, thePAIgGand PAIgM levels, and the activity of anti-dengue virus play key roles, both in the development and severity of the disease.

  1. PAIgG and PAIgM levels in secondary dengue virus infections lead to thrombocytopenia in patients from KP, Pakistan简

    Institute of Scientific and Technical Information of China (English)

    Ibrar; Alam; Said; Hassan; Iftikhar; Alam; Rahmat; Gul; Farhad; Ali; Ijaz; Ali; Sana; Ullah; Imtiaz; Ali; Khan; Aasif; Awan

    2015-01-01

    Objective: To understand the impact of platelet associated immunoglobulin G(PAIg G)/platelet associated immunoglobulin M(PAIg M) on severity of dengue virus infection leading to thrombocytopenia.Methods: In this study we examined a total of 52 patients who were having secondary infection of dengue in acute phase by using competitive ELISA.Results: A decrease in the platelet count was observed at the acute phase of infection while all along the recovery stage the count of platelet was significantly increased. A significant decrease was observed in PAIg G and PAIg M in these subjects. Inverse correlation was found between platelets count and PAIg G/PAIg M among the subjects studied. In the platelets elution from ten subjects, anti-dengue virus immunoglobulin G and immunoglobulin M were observed. PAIg G and PAIg M with inclined levels were higher in dengue hemorrhagic fever than the classical dengue fever. In the development of dengue hemorrhagic fever PAIg M inclined level was independently associated with high specificity, showing a possible indication of dengue hemorrhagic fever.Conclusions: This study suggests that in secondary dengue virus infection, the PAIg G and PAIg M levels, and the activity of anti-dengue virus play key roles, both in the development and severity of the disease.

  2. Single-Reaction Multiplex Reverse Transcription PCR for Detection of Zika, Chikungunya, and Dengue Viruses.

    Science.gov (United States)

    Waggoner, Jesse J; Gresh, Lionel; Mohamed-Hadley, Alisha; Ballesteros, Gabriela; Davila, Maria Jose Vargas; Tellez, Yolanda; Sahoo, Malaya K; Balmaseda, Angel; Harris, Eva; Pinsky, Benjamin A

    2016-07-01

    Clinical manifestations of Zika virus, chikungunya virus, and dengue virus infections can be similar. To improve virus detection, streamline molecular workflow, and decrease test costs, we developed and evaluated a multiplex real-time reverse transcription PCR for these viruses.

  3. Single-Reaction Multiplex Reverse Transcription PCR for Detection of Zika, Chikungunya, and Dengue Viruses

    OpenAIRE

    Waggoner, Jesse J.; Gresh, Lionel; Mohamed-Hadley, Alisha; Ballesteros, Gabriela; Davila, Maria Jose Vargas; Tellez, Yolanda; Sahoo, Malaya K.; Balmaseda, Angel; Harris, Eva; Pinsky, Benjamin A.

    2016-01-01

    Clinical manifestations of Zika virus, chikungunya virus, and dengue virus infections can be similar. To improve virus detection, streamline molecular workflow, and decrease test costs, we developed and evaluated a multiplex real-time reverse transcription PCR for these viruses.

  4. Gamma interferon augments Fc gamma receptor-mediated dengue virus infection of human monocytic cells.

    OpenAIRE

    Kontny, U.; Kurane, I; Ennis, F A

    1988-01-01

    It has been reported that anti-dengue antibodies at subneutralizing concentrations augment dengue virus infection of monocytic cells. This is due to the increased uptake of dengue virus in the form of virus-antibody complexes by cells via Fc gamma receptors. We analyzed the effects of recombinant human gamma interferon (rIFN-gamma) on dengue virus infection of human monocytic cells. U937 cells, a human monocytic cell line, were infected with dengue virus in the form of virus-antibody complexe...

  5. The Interplay of Dengue Virus Morphological Diversity and Human Antibodies.

    Science.gov (United States)

    Lok, Shee-Mei

    2016-04-01

    Dengue virus (DENV) infects ∼400 million people annually, and there is no available vaccine or therapeutics. It is not clear why candidate vaccines provide only modest protection. In addition to the presence of four different dengue serotypes, there is also structural heterogeneity in DENV infectious particles, even within a strain. This severely complicates the development of vaccines and therapeutics. The currently known different morphologies of DENV are: immature, partially mature, compact mature, and expanded mature forms of the virus. In this review I describe these forms of the virus, their infectivity, and how antibodies could recognize these morphologies. I also discuss possible vaccine and antibody therapeutic formulations to protect against all morphologies.

  6. Profile of hepatic involvement by dengue virus in dengue infected children

    Directory of Open Access Journals (Sweden)

    Amrita Roy

    2013-01-01

    Full Text Available Background: The spectrum of liver dysfunction in children with dengue infection is wide and has been associated with disease severity. Aims: This study was undertaken to estimate the range of hepatic involvement in dengue infection in children. Materials and Methods: This study assessed the biochemical and clinical profile of hepatic involvement by dengue virus in 120 children with serologically positive dengue fever (DF, aged 2 months to 14 years. Results: All cases were grouped into DF without warning signs (Group 1, DF with warning signs (Group 2 and severe dengue (Group 3 according to revised World Health Organization 2009 criteria. The spectrum of hepatic manifestations included hepatomegaly (80.8%, hepatic tenderness (46.3%, jaundice (60%, raised aspartate transaminase (AST, alanine transaminase (ALT and prolonged prothrombin time (41.7% and reduced serum albumin (56%. Conclusions: Hepatic dysfunction was observed more in Groups 2 and 3. There was 84.4% and 93.75% ALT and AST elevation respectively in Group 2 and 94.5% and 95.9% ALT and AST elevation respectively in Group 3 and fulminant hepatic failure was observed in Group 3. Therefore in a child with fever, jaundice, hepatomegaly and altered liver function tests, the diagnosis of dengue infection should be strongly considered in areas where dengue infection is endemic.

  7. New Genotype of Dengue Type 3 Virus Circulating in Brazil and Colombia Showed a Close Relationship to Old Asian Viruses

    OpenAIRE

    Victor Hugo Aquino; Alberto Anastacio Amarilla; Helda Liz Alfonso; Weber Cheli Batista; Luiz Tadeu Moraes Figueiredo

    2009-01-01

    Dengue type 3 genotype V viruses have been recently detected in Brazil and Colombia. In this study, we described another Brazilian isolate belonging to this genotype. Phylogenetic analysis including dengue type 3 viruses isolated worldwide showed that Brazilian and Colombian viruses were closely related to viruses isolated in Asia more than two decades ago. The characteristic evolutionary pattern of dengue type 3 virus cannot explain the close similarity of new circulating viruses with old vi...

  8. Analysis of the dengue disease model with two virus strains

    Science.gov (United States)

    Adi-Kusumo, F.; Aini, A. N.; Ridwan, M.

    2014-02-01

    Dengue fever (DF) and dengue haemorrhagic fever (DHF) are the disease caused by the dengue virus which is transmitted to the human by infected female mosquitoes. The disease is endemic in more than 100 countries over the world. Dengue virus has four distinct serotypes which are closely related to each other antigenically. A person who infected by the dengue virus will never be infected again by the same serotype, but he looses immunity from the three other serotypes. Infection with one serotype does not provide cross-protective immunity against to others. Here we assume that there are two serotypes exist in the population. Someone who has recovered from one serotype become susceptible to the other serotype and can be reinfected. In this paper we analyze the model of dengue fever with two infections from the different serotype by linear analysis. Then we study the effect of vaccination to the model. In numerical simulation, we use Runge-Kutta order 4 to integrate the solution of the system.

  9. The Aedes aegypti toll pathway controls dengue virus infection.

    Directory of Open Access Journals (Sweden)

    Zhiyong Xi

    2008-07-01

    Full Text Available Aedes aegypti, the mosquito vector of dengue viruses, utilizes its innate immune system to ward off a variety of pathogens, some of which can cause disease in humans. To date, the features of insects' innate immune defenses against viruses have mainly been studied in the fruit fly Drosophila melanogaster, which appears to utilize different immune pathways against different types of viruses, in addition to an RNA interference-based defense system. We have used the recently released whole-genome sequence of the Ae. aegypti mosquito, in combination with high-throughput gene expression and RNA interference (RNAi-based reverse genetic analyses, to characterize its response to dengue virus infection in different body compartments. We have further addressed the impact of the mosquito's endogenous microbial flora on virus infection. Our findings indicate a significant role for the Toll pathway in regulating resistance to dengue virus, as indicated by an infection-responsive regulation and functional assessment of several Toll pathway-associated genes. We have also shown that the mosquito's natural microbiota play a role in modulating the dengue virus infection, possibly through basal-level stimulation of the Toll immune pathway.

  10. Dengue and Severe Dengue

    Science.gov (United States)

    ... 686kB World Health Day 2014: Protect yourself from vector-borne diseases WHO's work on dengue Dengue (Special Programme for Research and Training in Tropical Diseases, TDR) Dengue vaccine development More about dengue Zika virus and potential complications Latest outbreaks Dengue Fever – ...

  11. Dengue Virus in Bats from Southeastern Mexico

    Science.gov (United States)

    Sotomayor-Bonilla, Jesús; Chaves, Andrea; Rico-Chávez, Oscar; Rostal, Melinda K.; Ojeda-Flores, Rafael; Salas-Rojas, Mónica; Aguilar-Setien, Álvaro; Ibáñez-Bernal, Sergio; Barbachano-Guerrero, Arturo; Gutiérrez-Espeleta, Gustavo; Aguilar-Faisal, J. Leopoldo; Aguirre, A. Alonso; Daszak, Peter; Suzán, Gerardo

    2014-01-01

    To identify the relationship between landscape use and dengue virus (DENV) occurrence in bats, we investigated the presence of DENV from anthropogenically changed and unaltered landscapes in two Biosphere Reserves: Calakmul (Campeche) and Montes Azules (Chiapas) in southern Mexico. Spleen samples of 146 bats, belonging to 16 species, were tested for four DENV serotypes with standard reverse transcriptase polymerase chain reaction (RT-PCR) protocols. Six bats (4.1%) tested positive for DENV-2: four bats in Calakmul (two Glossophaga soricina, one Artibeus jamaicensis, and one A. lituratus) and two bats in Montes Azules (both A. lituratus). No effect of anthropogenic disturbance on the occurrence of DENV was detected; however, all three RT-PCR–positive bat species are considered abundant species in the Neotropics and well-adapted to disturbed habitats. To our knowledge, this study is the first study conducted in southeastern Mexico to identify DENV-2 in bats by a widely accepted RT-PCR protocol. The role that bats play on DENV's ecology remains undetermined. PMID:24752688

  12. Human Immune Responses to Dengue Viruses.

    Science.gov (United States)

    1983-09-01

    accompanying proposal and very briefly include: 1) establishing satisfactory target cells for the other dengue serotypes : 1, 3 and 4, to use in...secondary natural infections on target cells infected with each of the dengue serotypes before this major question is satisfactorily addressed. These

  13. Release of dengue virus genome induced by a peptide inhibitor.

    Directory of Open Access Journals (Sweden)

    Shee-Mei Lok

    Full Text Available Dengue virus infects approximately 100 million people annually, but there is no available therapeutic treatment. The mimetic peptide, DN59, consists of residues corresponding to the membrane interacting, amphipathic stem region of the dengue virus envelope (E glycoprotein. This peptide is inhibitory to all four serotypes of dengue virus, as well as other flaviviruses. Cryo-electron microscopy image reconstruction of dengue virus particles incubated with DN59 showed that the virus particles were largely empty, concurrent with the formation of holes at the five-fold vertices. The release of RNA from the viral particle following incubation with DN59 was confirmed by increased sensitivity of the RNA genome to exogenous RNase and separation of the genome from the E protein in a tartrate density gradient. DN59 interacted strongly with synthetic lipid vesicles and caused membrane disruptions, but was found to be non-toxic to mammalian and insect cells. Thus DN59 inhibits flavivirus infectivity by interacting directly with virus particles resulting in release of the genomic RNA.

  14. Dengue virus antibody database: Systematically linking serotype-specificity with epitope mapping in dengue virus

    Science.gov (United States)

    Chaudhury, Sidhartha; Gromowski, Gregory D.; Ripoll, Daniel R.; Khavrutskii, Ilja V.; Desai, Valmik; Wallqvist, Anders

    2017-01-01

    Background A majority infections caused by dengue virus (DENV) are asymptomatic, but a higher incidence of severe illness, such as dengue hemorrhagic fever, is associated with secondary infections, suggesting that pre-existing immunity plays a central role in dengue pathogenesis. Primary infections are typically associated with a largely serotype-specific antibody response, while secondary infections show a shift to a broadly cross-reactive antibody response. Methods/Principal findings We hypothesized that the basis for the shift in serotype-specificity between primary and secondary infections can be found in a change in the antibody fine-specificity. To investigate the link between epitope- and serotype-specificity, we assembled the Dengue Virus Antibody Database, an online repository containing over 400 DENV-specific mAbs, each annotated with information on 1) its origin, including the immunogen, host immune history, and selection methods, 2) binding/neutralization data against all four DENV serotypes, and 3) epitope mapping at the domain or residue level to the DENV E protein. We combined epitope mapping and activity information to determine a residue-level index of epitope propensity and cross-reactivity and generated detailed composite epitope maps of primary and secondary antibody responses. We found differing patterns of epitope-specificity between primary and secondary infections, where secondary responses target a distinct subset of epitopes found in the primary response. We found that secondary infections were marked with an enhanced response to cross-reactive epitopes, such as the fusion-loop and E-dimer region, as well as increased cross-reactivity in what are typically more serotype-specific epitope regions, such as the domain I-II interface and domain III. Conclusions/Significance Our results support the theory that pre-existing cross-reactive memory B cells form the basis for the secondary antibody response, resulting in a broadening of the response

  15. Virus variation resources at the National Center for Biotechnology Information: dengue virus

    Directory of Open Access Journals (Sweden)

    Rozanov Michael

    2009-04-01

    Full Text Available Abstract Background There is an increasing number of complete and incomplete virus genome sequences available in public databases. This large body of sequence data harbors information about epidemiology, phylogeny, and virulence. Several specialized databases, such as the NCBI Influenza Virus Resource or the Los Alamos HIV database, offer sophisticated query interfaces along with integrated exploratory data analysis tools for individual virus species to facilitate extracting this information. Thus far, there has not been a comprehensive database for dengue virus, a significant public health threat. Results We have created an integrated web resource for dengue virus. The technology developed for the NCBI Influenza Virus Resource has been extended to process non-segmented dengue virus genomes. In order to allow efficient processing of the dengue genome, which is large in comparison with individual influenza segments, we developed an offline pre-alignment procedure which generates a multiple sequence alignment of all dengue sequences. The pre-calculated alignment is then used to rapidly create alignments of sequence subsets in response to user queries. This improvement in technology will also facilitate the incorporation of additional virus species in the future. The set of virus-specific databases at NCBI, which will be referred to as Virus Variation Resources (VVR, allow users to build complex queries against virus-specific databases and then apply exploratory data analysis tools to the results. The metadata is automatically collected where possible, and extended with data extracted from the literature. Conclusion The NCBI Dengue Virus Resource integrates dengue sequence information with relevant metadata (sample collection time and location, disease severity, serotype, sequenced genome region and facilitates retrieval and preliminary analysis of dengue sequences using integrated web analysis and visualization tools.

  16. Dengue Virus Exposures among Deployed U.S. Military Personnel.

    Science.gov (United States)

    Hesse, Elisabeth M; Martinez, Luis J; Jarman, Richard G; Lyons, Arthur G; Eckels, Kenneth H; De La Barrera, Rafael A; Thomas, Stephen J

    2017-02-13

    Dengue virus infections have adversely impacted U.S. military operations since the Spanish-American War. The erosion of mission capabilities and lost duty days are underestimated. Appreciating the incidence and prevalence of dengue infections in U.S. military personnel is important to inform disease prevention strategies. Banked pre- and post-deployment serum samples from 1,000 U.S. military personnel with a single deployment to a dengue-endemic region were tested using a screening microneutralization assay to detect anti-dengue-virus-neutralizing antibodies. A total of 76 (7.6%) post-deployment samples were positive and 15 of the pre-deployment samples were negative. These figures represent an infection incidence of 1.5% and total of 17.6 seroconversions per 10,000 deployment months. These data represent a deploying military population with a relatively high background rate of dengue seropositivity, a low level of infection during deployment compared with background infection rates in the local populations, and the potential for worsening clinical attack rates with increased frequency of deployment. Additional studies are required to more clearly elucidate the dengue infection and disease risk in U.S. military personnel.

  17. Evaluation of Commercially Available Assays for Diagnosis of Acute Dengue in Schoolchildren During an Epidemic Period in Medellin, Colombia.

    Science.gov (United States)

    Piedrahita, Leidy D; Agudelo, Ivony Y; Trujillo, Andrea I; Ramírez, Ruth E; Osorio, Jorge E; Restrepo, Berta N

    2016-08-03

    During an active surveillance study in school children in Medellin, we assessed the performance of two diagnostic strategies for dengue virus. A total of 41 patients with suspected dengue acute infection were evaluated. Diagnostic strategies consisted of one combining Panbio(®) Dengue virus IgM and IgG Capture ELISAs (enzyme-linked immunosorbent assays) with reverse transcriptase polymerase chain reaction (RT-PCR) and another using a commercial rapid SD Bioline Dengue Duo (IgG/IgM + NS1 Ag) test. These two strategies were compared with the enzyme-linked immunospot microneutralization test (ELISPOT-MNT). The sensitivity and specificity were 53.9% and 80.0% for the combination of Panbio(®) ELISAs and RT-PCR tests, and 30.8% and 73.3% for the SD Bioline Duo test, respectively. ELISPOT-MNT detected 16.4% additional cases and revealed the presence of neutralizing antibodies in all the acute samples, evidencing that they were all secondary infections. In contrast, Panbio(®) and SD Dengue Duo rapid tests only classified 23.0% and 26.9% of the cases as secondary dengue infections, respectively. Cohen's kappa coefficient and McNemar's association tests demonstrated a significant disagreement between the two diagnostic strategies and ELISPOT-MNT. Overall, these results evidence the relatively poor performances of commercial assays for the diagnosis of acute and secondary dengue infections, compared with ELISPOT-MNT, and raise concern about the accuracy of these assays for the diagnostic of dengue in endemic areas.

  18. Asian genotypes of dengue virus 4 in Brazil.

    Science.gov (United States)

    Pinho, A C O; Sardi, S I; Paula, F L; Peixoto, I B; Brandão, C J; Fernandez, F M C; Campos, G S

    2015-10-01

    Dengue virus, commonly transmitted by mosquitoes, causes a human disease of significant social impact and presents a serious public health problem in Brazil. This report describes the unusual emergence of DENV-4 in northern Brazil after a nearly 30-year-long absence. DENV-4 genotype I is of Asian origin and was identified in the serum of patients receiving treatment at a hospital serving the Salvador area (Brazilian state of Bahia). The identification of dengue virus serotypes through molecular and phylogenetic analysis is essential for predicting disease severity or fatal illness, principally in endemic countries such as Brazil.

  19. New genotype of dengue type 3 virus circulating in Brazil and Colombia showed a close relationship to old Asian viruses.

    Science.gov (United States)

    Aquino, Victor Hugo; Amarilla, Alberto Anastacio; Alfonso, Helda Liz; Batista, Weber Cheli; Figueiredo, Luiz Tadeu Moraes

    2009-10-13

    Dengue type 3 genotype V viruses have been recently detected in Brazil and Colombia. In this study, we described another Brazilian isolate belonging to this genotype. Phylogenetic analysis including dengue type 3 viruses isolated worldwide showed that Brazilian and Colombian viruses were closely related to viruses isolated in Asia more than two decades ago. The characteristic evolutionary pattern of dengue type 3 virus cannot explain the close similarity of new circulating viruses with old viruses. Further studies are needed to confirm the origin of the new dengue type III genotype circulating in Brazil and Colombia.

  20. New genotype of dengue type 3 virus circulating in Brazil and Colombia showed a close relationship to old Asian viruses.

    Directory of Open Access Journals (Sweden)

    Victor Hugo Aquino

    Full Text Available Dengue type 3 genotype V viruses have been recently detected in Brazil and Colombia. In this study, we described another Brazilian isolate belonging to this genotype. Phylogenetic analysis including dengue type 3 viruses isolated worldwide showed that Brazilian and Colombian viruses were closely related to viruses isolated in Asia more than two decades ago. The characteristic evolutionary pattern of dengue type 3 virus cannot explain the close similarity of new circulating viruses with old viruses. Further studies are needed to confirm the origin of the new dengue type III genotype circulating in Brazil and Colombia.

  1. An unusual cause of acute abdominal pain in dengue fever.

    Science.gov (United States)

    Waseem, Tariq; Latif, Hina; Shabbir, Bilquis

    2014-07-01

    Dengue fever is an acute febrile viral disease caused by the bite of Aedes aegypti mosquito. It is a major health problem especially in tropical and subtropical areas including South East Asia and Pakistan. In the past few years, dengue fever has been endemic in Northern Punjab. Physicians managing dengue fever come across varied and uncommon complications of dengue fever. We report a case of dengue fever that developed severe right upper quadrant abdominal pain and induration after extreme retching and vomiting for 2 days. A rectus sheath hematoma was confirmed on noncontrast computed tomography (CT). Rectus sheath hematoma as a complication of dengue fever has rarely been reported before and never from this part of the world. Rectus sheath hematoma is an uncommon and often clinically misdiagnosed cause of abdominal pain. It is the result of bleeding into the rectus sheath from damage to the superior or inferior epigastric artery or their branches or from a direct tear of the rectus muscle. It can mimic almost any abdominal condition (See Fig.) (See Table).

  2. Vector dynamics and transmission of dengue virus: implications for dengue surveillance and prevention strategies: vector dynamics and dengue prevention.

    Science.gov (United States)

    Scott, Thomas W; Morrison, Amy C

    2010-01-01

    Accounting for variation in mosquito vector populations will improve dengue surveillance and prevention. Because Aedes aegypti, the principle dengue virus (DENV) vector, transmit the virus with remarkable efficiency, entomological thresholds are especially low. Assessing risk of human infection based on immature mosquito indices has proven difficult. Greater emphasis should be placed on relative abundance of adult vectors in relation to human serotype-specific herd immunity, introduction of unique viruses, mosquito-human contact and weather. The most appropriate spatial scale for assessing entomological risk is the individual household. The scale for measuring DENV transmission risk has yet to be determined but is clearly larger than the household and likely to exceed several city blocks. Because households are expected to be a primary site for human DENV infection, intradomicile vector control strategies should be a priority, especially when the force of transmission is high. The most effective intervention strategy will combine vector control with vaccine delivery for rapid and sustained disease prevention.

  3. Dengue Virus Envelope Dimer Epitope Monoclonal Antibodies Isolated from Dengue Patients Are Protective against Zika Virus

    Directory of Open Access Journals (Sweden)

    J. A. Swanstrom

    2016-07-01

    Full Text Available Zika virus (ZIKV is a mosquito-borne flavivirus responsible for thousands of cases of severe fetal malformations and neurological disease since its introduction to Brazil in 2013. Antibodies to flaviviruses can be protective, resulting in lifelong immunity to reinfection by homologous virus. However, cross-reactive antibodies can complicate flavivirus diagnostics and promote more severe disease, as noted after serial dengue virus (DENV infections. The endemic circulation of DENV in South America and elsewhere raises concerns that preexisting flavivirus immunity may modulate ZIKV disease and transmission potential. Here, we report on the ability of human monoclonal antibodies and immune sera derived from dengue patients to neutralize contemporary epidemic ZIKV strains. We demonstrate that a class of human monoclonal antibodies isolated from DENV patients neutralizes ZIKV in cell culture and is protective in a lethal murine model. We also tested a large panel of convalescent-phase immune sera from humans exposed to primary and repeat DENV infection. Although ZIKV is most closely related to DENV compared to other human-pathogenic flaviviruses, most DENV immune sera (73% failed to neutralize ZIKV, while others had low (50% effective concentration [EC50], 1:100 serum dilution; 9% levels of cross-neutralizing antibodies. Our results establish that ZIKV and DENV share epitopes that are targeted by neutralizing, protective human antibodies. The availability of potently neutralizing human monoclonal antibodies provides an immunotherapeutic approach to control life-threatening ZIKV infection and also points to the possibility of repurposing DENV vaccines to induce cross-protective immunity to ZIKV.

  4. Phenotyping of peripheral blood mononuclear cells during acute dengue illness demonstrates infection and increased activation of monocytes in severe cases compared to classic dengue fever.

    Science.gov (United States)

    Durbin, Anna P; Vargas, Maria José; Wanionek, Kimberli; Hammond, Samantha N; Gordon, Aubree; Rocha, Crisanta; Balmaseda, Angel; Harris, Eva

    2008-07-05

    In vitro studies have attempted to identify dengue virus (DEN) target cells in peripheral blood; however, extensive phenotyping of peripheral blood mononuclear cells (PBMCs) from dengue patients has not been reported. PBMCs collected from hospitalized children suspected of acute dengue were analyzed for DEN prM, CD32, CD86, CD14, CD11c, CD16, CD209, CCR7, CD4, and CD8 by flow cytometry to detect DEN antigen in PBMCs and to phenotype DEN-positive cells. DEN prM was detected primarily in activated monocytes (CD14(+), CD32(+), CD86(+), CD11c(+)). A subset of samples analyzed for DEN nonstructural protein 3 (NS3) confirmed that approximately half of DEN antigen-positive cells contained replicating virus. A higher percentage of PBMCs from DHF patients expressed prM, CD86, CD32, and CD11c than did those from DF patients. Increased activation of monocytes and greater numbers of DEN-infected cells were associated with more severe dengue, implicating a role for monocyte activation in dengue immunopathogenesis.

  5. Novel dengue virus type 1 from travelers to Yap State, Micronesia.

    Science.gov (United States)

    Nukui, Yoko; Tajima, Shigeru; Kotaki, Akira; Ito, Mikako; Takasaki, Tomohiko; Koike, Kazuhiko; Kurane, Ichiro

    2006-02-01

    Dengue virus type 1 (DENV-1), which was responsible for the dengue fever outbreak in Yap State, Micronesia, in 2004, was isolated from serum samples of 4 dengue patients in Japan. Genome sequencing demonstrated that this virus belonged to genotype IV and had a 29-nucleotide deletion in the 3 noncoding region.

  6. Co-circulation of Dengue and Chikungunya Viruses, Al Hudaydah, Yemen, 2012

    Science.gov (United States)

    El-Sawaf, Gamal; Faggioni, Giovanni; Vescio, Fenicia; Al Ameri, Ranya; De Santis, Riccardo; Helaly, Ghada; Pomponi, Alice; Metwally, Dalia; Fantini, Massimo; Qadi, Hussein; Ciccozzi, Massimo; Lista, Florigio

    2014-01-01

    We investigated 400 cases of dengue-like illness in persons hospitalized during an outbreak in Al Hudaydah, Yemen, in 2012. Overall, 116 dengue and 49 chikungunya cases were diagnosed. Dengue virus type 2 was the predominant serotype. The co-circulation of these viruses indicates that mosquitoborne infections represent a public health threat in Yemen. PMID:25061762

  7. Co-circulation of Dengue and Chikungunya Viruses, Al Hudaydah, Yemen, 2012.

    Science.gov (United States)

    Rezza, Giovanni; El-Sawaf, Gamal; Faggioni, Giovanni; Vescio, Fenicia; Al Ameri, Ranya; De Santis, Riccardo; Helaly, Ghada; Pomponi, Alice; Metwally, Dalia; Fantini, Massimo; Qadi, Hussein; Ciccozzi, Massimo; Lista, Florigio

    2014-08-01

    We investigated 400 cases of dengue-like illness in persons hospitalized during an outbreak in Al Hudaydah, Yemen, in 2012. Overall, 116 dengue and 49 chikungunya cases were diagnosed. Dengue virus type 2 was the predominant serotype. The co-circulation of these viruses indicates that mosquitoborne infections represent a public health threat in Yemen.

  8. Discovery of insect and human dengue virus host factors.

    Science.gov (United States)

    Sessions, October M; Barrows, Nicholas J; Souza-Neto, Jayme A; Robinson, Timothy J; Hershey, Christine L; Rodgers, Mary A; Ramirez, Jose L; Dimopoulos, George; Yang, Priscilla L; Pearson, James L; Garcia-Blanco, Mariano A

    2009-04-23

    Dengue fever is the most frequent arthropod-borne viral disease of humans, with almost half of the world's population at risk of infection. The high prevalence, lack of an effective vaccine, and absence of specific treatment conspire to make dengue fever a global public health threat. Given their compact genomes, dengue viruses (DENV-1-4) and other flaviviruses probably require an extensive number of host factors; however, only a limited number of human, and an even smaller number of insect host factors, have been identified. Here we identify insect host factors required for DENV-2 propagation, by carrying out a genome-wide RNA interference screen in Drosophila melanogaster cells using a well-established 22,632 double-stranded RNA library. This screen identified 116 candidate dengue virus host factors (DVHFs). Although some were previously associated with flaviviruses (for example, V-ATPases and alpha-glucosidases), most of the DVHFs were newly implicated in dengue virus propagation. The dipteran DVHFs had 82 readily recognizable human homologues and, using a targeted short-interfering-RNA screen, we showed that 42 of these are human DVHFs. This indicates notable conservation of required factors between dipteran and human hosts. This work suggests new approaches to control infection in the insect vector and the mammalian host.

  9. n Silico Analysis of Envelope Dengue Virus-2 and Envelope Dengue Virus-3 Protein as the Backbone of Dengue Virus Tetravalent Vaccine by Using Homology Modeling Method

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    Rizky I. Taufik

    2009-01-01

    Full Text Available Problem statement: Dengue fever, which was caused by Dengue virus infection, had became a major public health problem in the tropic and subtropical countries. Dengue virus (DENV had four serotypes (DENV-1, DENV-2, DENV-3 and DENV-4, based on their immunogenic in the human body. Preventive measure will be necessary to decrease the prevalence of dengue fever, by developing modern vaccine. Approach: This research was focused on in silico study of dengue virus vaccines, by using envelope (E protein of DENV-2 and DENV-3 as their backbones. T cell epitope prediction was determined by using MULTIPRED server and B cell epitope prediction was determined by using Conformational Epitope Prediction server (CEP. Homology modeling study of E DENV-3 protein as the vaccine backbone had produced six dengue vaccine peptides (HMM Vaccine 1-6. Moreover, homology modeling study of E DENV-2 protein as vaccine backbone had produced six dengue vaccine peptides (ANN vaccine 1-6. Results: The BLAST analysis of HMM and ANN vaccines had produced 93% and 91% identity, respectively. The Ramachandran Plot of both vaccines had shown less than 15% non glycine residue in the disallowed region, therefore it showed the solid stability of the proteins. The VAST analysis of E DENV-3 backbone vaccines had determined, that HMM4 and HMM6 had the highest structure similarity with native E DENV-3. HMM4 and HMM6 had the highest VAST score of 64.5. Moreover, the VAST analysis of E DENV-2 backbone vaccines had determined, that ANN1, ANN3, ANN4, ANN5 and ANN6 had the highest structure similarity with native E DENV-2. ANN1, ANN3, ANN4, ANN5 and ANN6 have the highest VAST score of 64.7. Conclusion/Recommendation: It could be inferred from this research that HMM4; HMM6; ANN1; ANN3; ANN4; ANN5; and ANN6 were the best in silico vaccine design, based on their similarity with native E DENV Proteins. This research could be applied for the wet

  10. Dengue virus life cycle : viral and host factors modulating infectivity

    NARCIS (Netherlands)

    Rodenhuis-Zybert, Izabela A.; Wilschut, Jan; Smit, Jolanda M.

    2010-01-01

    Dengue virus (DENV 1-4) represents a major emerging arthropod-borne pathogen. All four DENV serotypes are prevalent in the (sub) tropical regions of the world and infect 50-100 million individuals annually. Whereas the majority of DENV infections proceed asymptomatically or result in self-limited de

  11. A small molecule fusion inhibitor of dengue virus

    NARCIS (Netherlands)

    Poh, Mee Kian; Yip, Andy; Zhang, Summer; Priestle, John P.; Ma, Ngai Ling; Smit, Jolanda M.; Wischut, Jan; Shi, Pei-Yong; Wenk, Markus R.; Schul, Wouter

    2009-01-01

    The dengue virus envelope protein plays an essential role in viral entry by mediating fusion between the viral and host membranes. The crystal structure of the envelope protein shows a pocket (located at a "hinge" between Domains I and II) that can be occupied by ligand n-octyl-beta-D-glucoside (bet

  12. Role of antibodies in controlling dengue virus infection

    NARCIS (Netherlands)

    van der Schaar, Hilde M.; Wilschut, Jan C.; Smit, Jolanda M.

    2009-01-01

    The incidence and disease burden of arthropod-borne flavivirus infections have dramatically increased during the last decades due to major societal and economic changes, including massive urbanization, lack of vector control, travel, and international trade. Specifically, in the case of dengue virus

  13. Dextran fractional clearance studies in acute dengue infection.

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    Julie Nguyen-Pouplin

    2011-08-01

    Full Text Available BACKGROUND: Although increased capillary permeability is the major clinical feature associated with severe dengue infections the mechanisms underlying this phenomenon remain unclear. Dextran clearance methodology has been used to investigate the molecular sieving properties of the microvasculature in clinical situations associated with altered permeability, including during pregnancy and in various renal disorders. In order to better understand the characteristics of the vascular leak associated with dengue we undertook formal dextran clearance studies in Vietnamese dengue patients and healthy volunteers. METHODOLOGY/PRINCIPAL FINDINGS: We carried out serial clearance studies in 15 young adult males with acute dengue and evidence of vascular leakage a during the phase of maximal leakage and b one and three months later, as well as in 16 healthy control subjects. Interestingly we found no difference in the clearance profiles of neutral dextran solutions among the dengue patients at any time-point or in comparison to the healthy volunteers. CONCLUSIONS/SIGNIFICANCE: The surface glycocalyx layer, a fibre-matrix of proteoglycans, glycosaminoglycans, and plasma proteins, forms a complex with the underlying endothelial cells to regulate plasma volume within circumscribed limits. It is likely that during dengue infections loss of plasma proteins from this layer alters the permeability characteristics of the complex; physical and/or electrostatic interactions between the dextran molecules and the glycocalyx structure may temporarily restore normal function, rendering the technique unsuitable for assessing permeability in these patients. The implications for resuscitation of patients with dengue shock syndrome (DSS are potentially important. It is possible that continuous low-dose infusions of dextran may help to stabilize the permeability barrier in patients with profound or refractory shock, reducing the need for repeated boluses, limiting the total

  14. Dengue Virus Immunopathogenesis: Lessons Applicable to the Emergence of Zika Virus.

    Science.gov (United States)

    Olagnier, David; Amatore, Donatella; Castiello, Luciano; Ferrari, Matteo; Palermo, Enrico; Diamond, Michael S; Palamara, Anna Teresa; Hiscott, John

    2016-08-28

    Dengue is the leading mosquito-transmitted viral infection in the world. There are more than 390 million new infections annually; while the majority of infected individuals are asymptomatic or develop a self-limited dengue fever, up to 1 million clinical cases develop severe manifestations, including dengue hemorrhagic fever and shock syndrome, resulting in ~25,000 deaths annually, mainly in children. Gaps in our understanding of the mechanisms that contribute to dengue infection and immunopathogenesis have hampered the development of vaccines and antiviral agents. Some of these limitations are highlighted by the explosive re-emergence of another arthropod-borne flavivirus-Zika virus-spread by the same vector, the Aedes aegypti mosquito, that also carries dengue, yellow fever and chikungunya viruses. This review will discuss the early virus-host interactions in dengue infection, with emphasis on the interrelationship between oxidative stress and innate immune pathways, and will provide insight as to how lessons learned from dengue research may expedite therapeutic strategies for Zika virus.

  15. The citrus flavanone naringenin impairs dengue virus replication in human cells

    Science.gov (United States)

    Frabasile, Sandra; Koishi, Andrea Cristine; Kuczera, Diogo; Silveira, Guilherme Ferreira; Verri, Waldiceu Aparecido; Duarte dos Santos, Claudia Nunes; Bordignon, Juliano

    2017-01-01

    Dengue is one of the most significant health problems in tropical and sub-tropical regions throughout the world. Nearly 390 million cases are reported each year. Although a vaccine was recently approved in certain countries, an anti-dengue virus drug is still needed. Fruits and vegetables may be sources of compounds with medicinal properties, such as flavonoids. This study demonstrates the anti-dengue virus activity of the citrus flavanone naringenin, a class of flavonoid. Naringenin prevented infection with four dengue virus serotypes in Huh7.5 cells. Additionally, experiments employing subgenomic RepDV-1 and RepDV-3 replicon systems confirmed the ability of naringenin to inhibit dengue virus replication. Antiviral activity was observed even when naringenin was used to treat Huh7.5 cells 24 h after dengue virus exposure. Finally, naringenin anti-dengue virus activity was demonstrated in primary human monocytes infected with dengue virus sertoype-4, supporting the potential use of naringenin to control dengue virus replication. In conclusion, naringenin is a suitable candidate molecule for the development of specific dengue virus treatments. PMID:28157234

  16. Transient CD4/CD8 ratio inversion and aberrant immune activation during dengue virus infection.

    Science.gov (United States)

    Liu, Ching-Chuan; Huang, Kao-Jean; Lin, Yee-Shin; Yeh, Trai-Ming; Liu, Hsiao-Sheng; Lei, Huan-Yao

    2002-10-01

    The immune status after dengue virus infection was studied in dengue patients from an outbreak of serotype 3 dengue virus infection in the southern part of Taiwan during November and December 1998. Consecutive blood samples from 29 dengue patients, of whom 21 had dengue fever and 8 had dengue hemorrhagic fever/dengue shock syndrome, were collected, and the immunophenotypes of the peripheral blood mononuclear cells were determined by flow cytometry. The early activation marker CD69 appeared on lymphocytes and monocytes at day 4 after the onset of fever, and declined afterward. However, a transient reverse in the CD4/CD8 ratio occurred at days 6-10 after the onset of fever. The CD4/CD8 ratio inversion was manifested in 10 of 29 dengue patients and was encountered more frequently in dengue hemorrhagic fever/dengue shock syndrome than in dengue fever patients. Analysis of the clinical blood cell count of these 10 cases showed that increase of immature neutrophils developed at fever days 5-6, CD4(dim) or CD8(dim) monocytosis at days 6-7, and atypical lymphocytosis at days 8-10 after the onset of fever. Serum IL-6 was found at either day 7 or day 9-11. The PHA-stimulated T-cell response was depressed as well. These changes in immune parameters indicate aberrant immune activation during dengue virus infection and might be involved in the pathogenesis of dengue virus infection.

  17. Phylogenetic reconstruction of dengue virus type 2 in Colombia

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    Méndez Jairo A

    2012-03-01

    Full Text Available Abstract Background Dengue fever is perhaps the most important viral re-emergent disease especially in tropical and sub-tropical countries, affecting about 50 million people around the world yearly. In Colombia, dengue virus was first detected in 1971 and still remains as a major public health issue. Although four viral serotypes have been recurrently identified, dengue virus type 2 (DENV-2 has been involved in the most important outbreaks during the last 20 years, including 2010 when the fatality rate highly increased. As there are no major studies reviewing virus origin and genotype distribution in this country, the present study attempts to reconstruct the phylogenetic history of DENV-2 using a sequence analysis from a 224 bp PCR-amplified product corresponding to the carboxyl terminus of the envelope (E gene from 48 Colombian isolates. Results As expected, the oldest isolates belonged to the American genotype (subtype V, but the strains collected since 1990 represent the American/Asian genotype (subtype IIIb as previously reported in different American countries. Interestingly, the introduction of this genotype coincides with the first report of dengue hemorrhagic fever in Colombia at the end of 1989 and the increase of cases during the next years. Conclusion After replacement of the American genotype, several lineages of American/Asian subtype have rapidly spread all over the country evolving in new clades. Nevertheless, the direct association of these new variants in the raise of lethality rate observed during the last outbreak has to be demonstrated.

  18. Human Immune Responses to Dengue Viruses.

    Science.gov (United States)

    1985-08-01

    FA titer of these antisera. We found using these hyper- immunized murine ascitis fluids that the homologous antiserum was most active in augmenting...statistically significant (pɘ.05). CHyperimmune mouse ascitis fluid was used as a source of anti-dengue 2 anti- body at a 1:20 dilution. dAx...by PBL without anti-dengue 2 antibody. *statistically significant (pɘ.05), l1not significant. bHyperimmune mouse ascitis fluid was used as a source

  19. Bilateral acute visual loss from Rathke's cleft cyst apoplexy in a patient with dengue fever

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    Ana Cláudia De Franco Suzuki

    2014-10-01

    Full Text Available Hemorrhagic complications of optic pathway diseases are extremely rare causes of acute visual loss associated with dengue fever. In this paper we report a patient presenting with dengue fever and bilateral acute visual loss caused by chiasmal compression due to Rathke's cleft cyst apoplexy. Considering the importance of early diagnosis and treatment to visual recovery, apoplexy of sellar and suprasellar tumors should be considered in the differential diagnosis of patients with acute visual loss and dengue fever.

  20. Vacunas contra el virus dengue: desarrollo histórico

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    Alicia Aguilar

    2003-06-01

    Full Text Available La Fiebre del Dengue (FD y la Fiebre Hemorrágica del Dengue (FHD han emergido como la principal enfermedad viral transmitida por artrópodos que afecta al hombre. Las características de la enfermedad, la ausencia de drogas antivirales contra la misma, el incremento en el número de enfermos, de países afectados y la dificultad para el control del vector han convertido el desarrollo de vacunas contra el dengue en una prioridad para la salud pública mundial. Los intentos para lograr este objetivo datan de mediados del siglo pasado para lo cual han sido exploradas diferentes estrategias. A pesar de los avances realizados al respecto mucho queda por aclarar y definir para disponer de un inmunógeno contra el virus.

  1. Recombinant Production of the Amino Terminal Cytoplasmic Region of Dengue Virus Non-Structural Protein 4A for Structural Studies

    OpenAIRE

    Yu-Fu Hung; Olga Valdau; Sven Schünke; Omer Stern; Koenig, Bernd W.; Dieter Willbold; Silke Hoffmann

    2014-01-01

    BACKGROUND: Dengue virus (DENV) is a mosquito-transmitted positive single strand RNA virus belonging to the Flaviviridae family. DENV causes dengue fever, currently the world's fastest-spreading tropical disease. Severe forms of the disease like dengue hemorrhagic fever and dengue shock syndrome are life-threatening. There is no specific treatment and no anti-DENV vaccines. Our recent data suggests that the amino terminal cytoplasmic region of the dengue virus non-structural protein 4A (NS4A)...

  2. Analytical and clinical performance of the CDC real time RT-PCR assay for detection and typing of dengue virus.

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    Gilberto A Santiago

    Full Text Available Dengue is an acute illness caused by the positive-strand RNA dengue virus (DENV. There are four genetically distinct DENVs (DENV-1-4 that cause disease in tropical and subtropical countries. Most patients are viremic when they present with symptoms; therefore, RT-PCR has been increasingly used in dengue diagnosis. The CDC DENV-1-4 RT-PCR Assay has been developed as an in-vitro diagnostic platform and was recently approved by the US Food and Drug Administration (FDA for detection of dengue in patients with signs or symptoms of mild or severe dengue. The primers and probes of this test have been designed to detect currently circulating strains of DENV-1-4 from around the world at comparable sensitivity. In a retrospective study with 102 dengue cases confirmed by IgM anti-DENV seroconversion in the convalescent sample, the RT-PCR Assay detected DENV RNA in 98.04% of the paired acute samples. Using sequencing as a positive indicator, the RT-PCR Assay had a 97.92% positive agreement in 86 suspected dengue patients with a single acute serum sample. After extensive validations, the RT-PCR Assay performance was highly reproducible when evaluated across three independent testing sites, did not produce false positive results for etiologic agents of other febrile illnesses, and was not affected by pathological levels of potentially interfering biomolecules. These results indicate that the CDC DENV-1-4 RT-PCR Assay provides a reliable diagnostic platform capable for confirming dengue in suspected cases.

  3. Cross-reactive memory CD8(+) T cells alter the immune response to heterologous secondary dengue virus infections in mice in a sequence-specific manner.

    Science.gov (United States)

    Beaumier, Coreen M; Mathew, Anuja; Bashyam, Hema S; Rothman, Alan L

    2008-02-15

    Dengue virus is the causative agent of dengue fever and the more-severe dengue hemorrhagic fever (DHF). Human studies suggest that the increased risk of DHF during secondary infection is due to immunopathology partially mediated by cross-reactive memory T cells from the primary infection. To model T cell responses to sequential infections, we immunized mice with different sequences of dengue virus serotypes and measured the frequency of peptide-specific T cells after infection. The acute response after heterologous secondary infections was enhanced compared with the acute or memory response after primary infection. Also, the hierarchy of epitope-specific responses was influenced by the specific sequence of infection. Adoptive-transfer experiments showed that memory T cells responded preferentially to the secondary infection. These findings demonstrate that cross-reactive T cells from a primary infection alter the immune response during a heterologous secondary infection.

  4. Proteasome Inhibition Suppresses Dengue Virus Egress in Antibody Dependent Infection.

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    Milly M Choy

    2015-11-01

    Full Text Available The mosquito-borne dengue virus (DENV is a cause of significant global health burden, with an estimated 390 million infections occurring annually. However, no licensed vaccine or specific antiviral treatment for dengue is available. DENV interacts with host cell factors to complete its life cycle although this virus-host interplay remains to be fully elucidated. Many studies have identified the ubiquitin proteasome pathway (UPP to be important for successful DENV production, but how the UPP contributes to DENV life cycle as host factors remains ill defined. We show here that proteasome inhibition decouples infectious virus production from viral RNA replication in antibody-dependent infection of THP-1 cells. Molecular and imaging analyses in β-lactone treated THP-1 cells suggest that proteasome function does not prevent virus assembly but rather DENV egress. Intriguingly, the licensed proteasome inhibitor, bortezomib, is able to inhibit DENV titers at low nanomolar drug concentrations for different strains of all four serotypes of DENV in primary monocytes. Furthermore, bortezomib treatment of DENV-infected mice inhibited the spread of DENV in the spleen as well as the overall pathological changes. Our findings suggest that preventing DENV egress through proteasome inhibition could be a suitable therapeutic strategy against dengue.

  5. Diagnostic Options and Challenges for Dengue and Chikungunya Viruses

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    Stacey K. Mardekian

    2015-01-01

    Full Text Available Dengue virus (DENV and Chikungunya virus (CHIKV are arboviruses that share the same Aedes mosquito vectors and thus overlap in their endemic areas. These two viruses also cause similar clinical presentations, especially in the initial stages of infection, with neither virus possessing any specific distinguishing clinical features. Because the outcomes and management strategies for these two viruses are vastly different, early and accurate diagnosis is imperative. Diagnosis is also important for surveillance, outbreak control, and research related to vaccine and drug development. Available diagnostic tests are aimed at detection of the virus, its antigenic components, or the host immune antibody response. In this review, we describe the recent progress and continued challenges related to the diagnosis of DENV and CHIKV infections.

  6. Diagnostic Options and Challenges for Dengue and Chikungunya Viruses.

    Science.gov (United States)

    Mardekian, Stacey K; Roberts, Amity L

    2015-01-01

    Dengue virus (DENV) and Chikungunya virus (CHIKV) are arboviruses that share the same Aedes mosquito vectors and thus overlap in their endemic areas. These two viruses also cause similar clinical presentations, especially in the initial stages of infection, with neither virus possessing any specific distinguishing clinical features. Because the outcomes and management strategies for these two viruses are vastly different, early and accurate diagnosis is imperative. Diagnosis is also important for surveillance, outbreak control, and research related to vaccine and drug development. Available diagnostic tests are aimed at detection of the virus, its antigenic components, or the host immune antibody response. In this review, we describe the recent progress and continued challenges related to the diagnosis of DENV and CHIKV infections.

  7. Molecular surveillance of dengue in Semarang, Indonesia revealed the circulation of an old genotype of dengue virus serotype-1.

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    Sukmal Fahri

    Full Text Available Dengue disease is currently a major health problem in Indonesia and affects all provinces in the country, including Semarang Municipality, Central Java province. While dengue is endemic in this region, only limited data on the disease epidemiology is available. To understand the dynamics of dengue in Semarang, we conducted clinical, virological, and demographical surveillance of dengue in Semarang and its surrounding regions in 2012. Dengue cases were detected in both urban and rural areas located in various geographical features, including the coastal and highland areas. During an eight months' study, a total of 120 febrile patients were recruited, of which 66 were serologically confirmed for dengue infection using IgG/IgM ELISA and/or NS1 tests. The cases occurred both in dry and wet seasons. Majority of patients were under 10 years old. Most patients were diagnosed as dengue hemorrhagic fever, followed by dengue shock syndrome and dengue fever. Serotyping was performed in 31 patients, and we observed the co-circulation of all four dengue virus (DENV serotypes. When the serotypes were correlated with the severity of the disease, no direct correlation was observed. Phylogenetic analysis of DENV based on Envelope gene sequence revealed the circulation of DENV-2 Cosmopolitan genotype and DENV-3 Genotype I. A striking finding was observed for DENV-1, in which we found the co-circulation of Genotype I with an old Genotype II. The Genotype II was represented by a virus strain that has a very slow mutation rate and is very closely related to the DENV strain from Thailand, isolated in 1964 and never reported in other countries in the last three decades. Moreover, this virus was discovered in a cool highland area with an elevation of 1,001 meters above the sea level. The discovery of this old DENV strain may suggest the silent circulation of old virus strains in Indonesia.

  8. Comparison of real-time SYBR green dengue assay with real-time taqman RT-PCR dengue assay and the conventional nested PCR for diagnosis of primary and secondary dengue infection

    OpenAIRE

    Damodar Paudel; Richard Jarman; Kriengsak Limkittikul; Chonticha Klungthong; Supat Chamnanchanunt; Ananda Nisalak; Robert Gibbons; Watcharee Chokejindachai

    2011-01-01

    Background : Dengue fever and dengue hemorrhagic fever are caused by dengue virus. Dengue infection remains a burning problem of many countries. To diagnose acute dengue in the early phase we improve the low cost, rapid SYBR green real time assay and compared the sensitivity and specificity with real time Taqman® assay and conventional nested PCR assay. Aims: To develop low cost, rapid and reliable real time SYBR green diagnostic dengue assay and compare with Taqman real-time assay and conven...

  9. Chimeric yellow fever/dengue virus as a candidate dengue vaccine: quantitation of the dengue virus-specific CD8 T-cell response.

    Science.gov (United States)

    van Der Most, R G; Murali-Krishna, K; Ahmed, R; Strauss, J H

    2000-09-01

    We have constructed a chimeric yellow fever/dengue (YF/DEN) virus, which expresses the premembrane (prM) and envelope (E) genes from DEN type 2 (DEN-2) virus in a YF virus (YFV-17D) genetic background. Immunization of BALB/c mice with this chimeric virus induced a CD8 T-cell response specific for the DEN-2 virus prM and E proteins. This response protected YF/DEN virus-immunized mice against lethal dengue encephalitis. Control mice immunized with the parental YFV-17D were not protected against DEN-2 virus challenge, indicating that protection was mediated by the DEN-2 virus prM- and E-specific immune responses. YF/DEN vaccine-primed CD8 T cells expanded and were efficiently recruited into the central nervous systems of DEN-2 virus challenged mice. At 5 days after challenge, 3 to 4% of CD8 T cells in the spleen were specific for the prM and E proteins, and 34% of CD8 T cells in the central nervous system recognized these proteins. Depletion of either CD4 or CD8 T cells, or both, strongly reduced the protective efficacy of the YF/DEN virus, stressing the key role of the antiviral T-cell response.

  10. Biological characteristics of dengue virus and potential targets for drug design

    Institute of Scientific and Technical Information of China (English)

    Rui-feng Qi; Ling Zhang; Cheng-wu Chi

    2008-01-01

    Dengue infection is a major cause of morbidity in tropical and subtropical regions, bringing nearly 40% of the world population at risk and causing more than 20,000 deaths per year. But there is neither a vaccine for dengue disease nor antiviral drugs to treat the infection. In recent years, dengue infection has been particularly prevalent in India, Southeast Asia, Brazil, and Guangdong Province, China. In this article, we present a brief summary of the biological characteristics of dengue virus and associated flaviviruses, and outline the progress on studies of vaccines and drugs based on potential targets of the dengue virus.

  11. Unusual dengue virus 3 epidemic in Nicaragua, 2009.

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    Gamaliel Gutierrez

    2011-11-01

    Full Text Available The four dengue virus serotypes (DENV1-4 cause the most prevalent mosquito-borne viral disease affecting humans worldwide. In 2009, Nicaragua experienced the largest dengue epidemic in over a decade, marked by unusual clinical presentation, as observed in two prospective studies of pediatric dengue in Managua. From August 2009-January 2010, 212 dengue cases were confirmed among 396 study participants at the National Pediatric Reference Hospital. In our parallel community-based cohort study, 170 dengue cases were recorded in 2009-10, compared to 13-65 cases in 2004-9. In both studies, significantly more patients experienced "compensated shock" (poor capillary refill plus cold extremities, tachycardia, tachypnea, and/or weak pulse in 2009-10 than in previous years (42.5% [90/212] vs. 24.7% [82/332] in the hospital study (p<0.001 and 17% [29/170] vs. 2.2% [4/181] in the cohort study (p<0.001. Signs of poor peripheral perfusion presented significantly earlier (1-2 days in 2009-10 than in previous years according to Kaplan-Meier survival analysis. In the hospital study, 19.8% of subjects were transferred to intensive care, compared to 7.1% in previous years - similar to the cohort study. DENV-3 predominated in 2008-9, 2009-10, and 2010-11, and full-length sequencing revealed no major genetic changes from 2008-9 to 2010-11. In 2008-9 and 2010-11, typical dengue was observed; only in 2009-10 was unusual presentation noted. Multivariate analysis revealed only "2009-10" as a significant risk factor for Dengue Fever with Compensated Shock. Interestingly, circulation of pandemic influenza A-H1N1 2009 in Managua was shifted such that it overlapped with the dengue epidemic. We hypothesize that prior influenza A H1N1 2009 infection may have modulated subsequent DENV infection, and initial results of an ongoing study suggest increased risk of shock among children with anti-H1N1-2009 antibodies. This study demonstrates that parameters other than serotype, viral

  12. KDEL Receptors Assist Dengue Virus Exit from the Endoplasmic Reticulum

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    Ming Yuan Li

    2015-03-01

    Full Text Available Membrane receptors at the surface of target cells are key host factors for virion entry; however, it is unknown whether trafficking and secretion of progeny virus requires host intracellular receptors. In this study, we demonstrate that dengue virus (DENV interacts with KDEL receptors (KDELR, which cycle between the ER and Golgi apparatus, for vesicular transport from ER to Golgi. Depletion of KDELR by siRNA reduced egress of both DENV progeny and recombinant subviral particles (RSPs. Coimmunoprecipitation of KDELR with dengue structural protein prM required three positively charged residues at the N terminus, whose mutation disrupted protein interaction and inhibited RSP transport from the ER to the Golgi. Finally, siRNA depletion of class II Arfs, which results in KDELR accumulation in the Golgi, phenocopied results obtained with mutagenized prME and KDELR knockdown. Our results have uncovered a function for KDELR as an internal receptor involved in DENV trafficking.

  13. Mouse models to study dengue virus immunology and pathogenesis

    Directory of Open Access Journals (Sweden)

    Raphaël M. Zellweger

    2014-04-01

    Full Text Available The development of a compelling murine model of dengue virus (DENV infection has been challenging, because dengue virus clinical isolates do not readily replicate or cause pathology in immunocompetent mice. However, research using immunocompromised mice and/or mouse-adapted viruses allows to investigate questions that may be impossible to address in human studies. In this review, we discuss the potential strengths and limitations of existing mouse models of dengue disease. Human studies are descriptive by nature; moreover, the strain, time, and sequence of infection are often unknown. In contrast, in mice, the conditions of infection are well defined and a large number of experimental parameters can be varied at will. Therefore, mouse models offer an opportunity to experimentally test hypotheses that are based on epidemiological observations. In particular, gain-of-function or loss-of-function models can be established to assess how different components of the immune system (either alone or in combination contribute to protection or pathogenesis during secondary infections or after vaccination. In addition, mouse models have been used for pre-clinical testing of antiviral drug or for vaccine development studies. Conclusions based on mouse experiments must be extrapolated to DENV infection in humans with caution due to the inherent limitations of animal models. However, research in mouse models is a useful complement to in vitro and epidemiological data, and may delineate new areas that deserve attention during future human studies.

  14. Dengue virus surveillance in Singapore reveals high viral diversity through multiple introductions and in situ evolution.

    Science.gov (United States)

    Lee, Kim-Sung; Lo, Sharon; Tan, Sharon Siok-Yin; Chua, Rachel; Tan, Li-Kiang; Xu, Helen; Ng, Lee-Ching

    2012-01-01

    Dengue fever, a vector-borne disease, has caused tremendous burden to countries in the tropics and sub tropics. Over the past 20 years, dengue epidemics have become more widespread, severe and frequent. This study aims to understand the dynamics of dengue viruses in cosmopolitan Singapore. Envelope protein gene sequences of all four dengue serotypes (DENV-1-DENV-4) obtained from human sera in Singapore (2008-2010) revealed that constant viral introductions and in situ evolution contribute to viral diversity in Singapore and play important roles in shaping the epidemiology of dengue in the island state. The diversity of dengue viruses reported here could be a reflection of the on-going dengue situation in the region given Singapore's location in a dengue hyperendemic region and its role as the regional hub for travels and trade. Though cosmopolitan genotype of DENV-2 has remained as the predominant strain circulating in Singapore, we uncovered evidence of in situ evolution which could possibly result in viruses with improved fitness. While we have previously shown that a switch in the predominant dengue serotype could serve as a warning for an impending outbreak, our current data shows that a replacement of a predominant viral clade, even in the absence of a switch in predominant serotype, could signal a possible increase in dengue transmission. The circulating dengue viruses in Singapore are highly diverse, a situation which could offer ample opportunities for selection of strains of higher fitness, thus increasing the risk of outbreaks despite a low Aedes population.

  15. Molecular characterization of dengue viruses circulating during 2009-2012 in Uttar Pradesh, India.

    Science.gov (United States)

    Mishra, Gitika; Jain, Amita; Prakash, Om; Prakash, Shantanu; Kumar, Rashmi; Garg, Ravindra K; Pandey, Nidhi; Singh, Mastan

    2015-01-01

    Dengue is the most rapidly spreading mosquito-borne viral disease in the world; in India it has taken endemic proportion implicating all the four known dengue virus serotypes. Dengue infection is caused by a small, single stranded RNA virus comprising of four antigenically distinct virus serotypes designated as dengue virus type 1-4 (DENV-1-4). On the basis of genomic variations, each serotype is classified further into its genotypes. Epidemiological studies have shown that the emergence of a newer dengue serotype/genotype after an interval always leads to a major outbreak; therefore a continuous epidemiological surveillance is needed to monitor the epidemiology of dengue viruses. The present study was planned to identify the serotype/genotype of dengue viruses circulating in Uttar Pradesh, India. Of 433 dengue suspected patients, tested by reverse transcriptase PCR (RT-PCR), 136 were positive for dengue virus RNA. Of these, DENV-1, 2, and 3 were detected in 26 (19.1%), 77 (56.6%), and 33 (24.3%) patients, respectively. Of 136 RT-PCR positive samples, 24 samples were sequenced to identify their genotypes. For sequencing C-prM gene junction of dengue virus genome was chosen. Phylogenetic analysis of sequenced dengue strains revealed that all the 12 DENV-1 strains were genotype III, all the eight DENV-2 strains were genotype IV (Cosmopolitan genotype) and among four DENV-3 strains, three were genotype III and one was genotype I. In conclusion, the co-circulation of multiple dengue virus serotypes and genotypes is alarming in U.P., India.

  16. Structural basis of potent Zika-dengue virus antibody cross-neutralization.

    Science.gov (United States)

    Barba-Spaeth, Giovanna; Dejnirattisai, Wanwisa; Rouvinski, Alexander; Vaney, Marie-Christine; Medits, Iris; Sharma, Arvind; Simon-Lorière, Etienne; Sakuntabhai, Anavaj; Cao-Lormeau, Van-Mai; Haouz, Ahmed; England, Patrick; Stiasny, Karin; Mongkolsapaya, Juthathip; Heinz, Franz X; Screaton, Gavin R; Rey, Félix A

    2016-08-01

    Zika virus is a member of the Flavivirus genus that had not been associated with severe disease in humans until the recent outbreaks, when it was linked to microcephaly in newborns in Brazil and to Guillain-Barré syndrome in adults in French Polynesia. Zika virus is related to dengue virus, and here we report that a subset of antibodies targeting a conformational epitope isolated from patients with dengue virus also potently neutralize Zika virus. The crystal structure of two of these antibodies in complex with the envelope protein of Zika virus reveals the details of a conserved epitope, which is also the site of interaction of the envelope protein dimer with the precursor membrane (prM) protein during virus maturation. Comparison of the Zika and dengue virus immunocomplexes provides a lead for rational, epitope-focused design of a universal vaccine capable of eliciting potent cross-neutralizing antibodies to protect simultaneously against both Zika and dengue virus infections.

  17. High pro-inflammatory cytokine secretion and loss of high avidity cross-reactive cytotoxic T-cells during the course of secondary dengue virus infection.

    Directory of Open Access Journals (Sweden)

    Tao Dong

    Full Text Available BACKGROUND: Dengue is one of the most important human diseases transmitted by an arthropod vector and the incidence of dengue virus infection has been increasing - over half the world's population now live in areas at risk of infection. Most infections are asymptomatic, but a subset of patients experience a potentially fatal shock syndrome characterised by plasma leakage. Severe forms of dengue are epidemiologically associated with repeated infection by more than one of the four dengue virus serotypes. Generally attributed to the phenomenon of antibody-dependent enhancement, recent observations indicate that T-cells may also influence disease phenotype. METHODS AND FINDINGS: Virus-specific cytotoxic T lymphocytes (CTL showing high level cross reactivity between dengue serotypes could be expanded from blood samples taken during the acute phase of secondary dengue infection. These could not be detected in convalescence when only CTL populations demonstrating significant serotype specificity were identified. Dengue cross-reactive CTL clones derived from these patients were of higher avidity than serotype-specific clones and produced much higher levels of both type 1 and certain type 2 cytokines, many previously implicated in dengue pathogenesis. CONCLUSION: Dengue serotype cross-reactive CTL clones showing high avidity for antigen produce higher levels of inflammatory cytokines than serotype-specific clones. That such cells cannot be expanded from convalescent samples suggests that they may be depleted, perhaps as a consequence of activation-induced cell death. Such high avidity cross-reactive memory CTL may produce inflammatory cytokines during the course of secondary infection, contributing to the pathogenesis of vascular leak. These cells appear to be subsequently deleted leaving a more serotype-specific memory CTL pool. Further studies are needed to relate these cellular observations to disease phenotype in a large group of patients. If

  18. Analysis of Dengue Virus Genetic Diversity during Human and Mosquito Infection Reveals Genetic Constraints.

    Science.gov (United States)

    Sessions, October M; Wilm, Andreas; Kamaraj, Uma Sangumathi; Choy, Milly M; Chow, Angelia; Chong, Yuwen; Ong, Xin Mei; Nagarajan, Niranjan; Cook, Alex R; Ooi, Eng Eong

    2015-01-01

    Dengue viruses (DENV) cause debilitating and potentially life-threatening acute disease throughout the tropical world. While drug development efforts are underway, there are concerns that resistant strains will emerge rapidly. Indeed, antiviral drugs that target even conserved regions in other RNA viruses lose efficacy over time as the virus mutates. Here, we sought to determine if there are regions in the DENV genome that are not only evolutionarily conserved but genetically constrained in their ability to mutate and could hence serve as better antiviral targets. High-throughput sequencing of DENV-1 genome directly from twelve, paired dengue patients' sera and then passaging these sera into the two primary mosquito vectors showed consistent and distinct sequence changes during infection. In particular, two residues in the NS5 protein coding sequence appear to be specifically acquired during infection in Ae. aegypti but not Ae. albopictus. Importantly, we identified a region within the NS3 protein coding sequence that is refractory to mutation during human and mosquito infection. Collectively, these findings provide fresh insights into antiviral targets and could serve as an approach to defining evolutionarily constrained regions for therapeutic targeting in other RNA viruses.

  19. Dengue virus cell entry : Unraveling the role of antibodies, maturation status, and antiviral drugs

    NARCIS (Netherlands)

    Ayala Nunez, Vanesa

    2014-01-01

    Antibody-dependent enhancement (ADE) is thought to play a critical role in the exacerbation of dengue virus-induced disease during a heterologous re-infection. Pre-existing cross-reactive anti-dengue antibodies are generally believed to bind to the newly infecting DENV and target the antibody-virus

  20. Depletion of macrophages in mice results in higher dengue virus titers and highlights the role of macrophages for virus control

    NARCIS (Netherlands)

    Fink, K.; Ng, C.; Nkenfou, C.; Vasudevan, S.G.; Rooijen, van N.; Schul, W.

    2009-01-01

    Monocytes and macrophages are target cells for dengue infection. Besides their potential role for virus replication, activated monocytes/macrophages produce cytokines that may be critical for dengue pathology. To study the in vivo role of monocytes and macrophages for virus replication, we depleted

  1. T-cell responses to dengue virus in humans.

    Science.gov (United States)

    Kurane, Ichiro; Matsutani, Takaji; Suzuki, Ryuji; Takasaki, Tomohiko; Kalayanarooj, Siripen; Green, Sharone; Rothman, Alan L; Ennis, Francis A

    2011-12-01

    Dengue virus (DENV) is a leading cause of morbidity and mortality in most tropical and subtropical areas of the world. Dengue virus infection induces specific CD4+CD8- and CD8+CD4- T cells in humans. In primary infection, T-cell responses to DENV are serotype cross-reactive, but the highest response is to the serotype that caused the infection. The epitopes recognized by DENV-specific T cells are located in most of the structural and non-structural proteins, but NS3 is the protein that is most dominantly recognized. In patients with dengue hemorrhagic fever (DHF) caused by secondary DENV infection, T cells are highly activated in vivo. These highly activated T cells are DENV-specific and oligoclonal. Multiple kinds of lymphokines are produced by the activated T cells, and it has been hypothesized that these lymphokines are responsible for induction of plasma leakage, one of the most characteristic features of DHF. Thus, T-cells play important roles in the pathogenesis of DHF and in the recovery from DENV infection.

  2. Human and mosquito infections by dengue viruses during and after epidemics in a dengue-endemic region of Colombia.

    Science.gov (United States)

    Méndez, Fabián; Barreto, Mauricio; Arias, Juan F; Rengifo, Graciela; Muñoz, Jaime; Burbano, María E; Parra, Beatriz

    2006-04-01

    We conducted a study in a dengue-endemic area of Colombia to evaluate the dynamics of transmission of dengue viruses during and after epidemics. Information was simultaneously gathered about occurrence of infection in humans and mosquitoes every three months in four cities with endemic transmission. Viral isolation was confirmed in 6.7% of the persons and most were asymptomatic. Adult mosquito and larvae house indexes were not found associated with increased burden of disease. The only entomologic indicator related to dengue infection in humans was the pooled infection rate of mosquitoes. Aedes aegypti infection rates showed significant differences between the epidemic (10.68, 95% confidence interval [CI] = 7.04-15.62) and after epidemic periods of the study (6.15, 95% CI = 3.46-10.19). In addition, Ae. albopictus were also infected with dengue viruses. Increases in mosquito infection rates were associated with increases in human infection rates in the following trimester.

  3. Frequent In-Migration and Highly Focal Transmission of Dengue Viruses among Children in Kamphaeng Phet, Thailand

    Science.gov (United States)

    2013-01-17

    the replication kinetics of the ChimeriVax-DEN 1, 2, 3, 4 tetravalent virus mixture in Aedes aegypti by real-time reverse transcriptase- polymerase... control number. 1. REPORT DATE JAN 2013 2. REPORT TYPE 3. DATES COVERED 00-00-2013 to 00-00-2013 4. TITLE AND SUBTITLE Frequent In-Migration and...cluster investigation; non-dengue acutely ill subjects served as index cases for negative control clusters. In each cluster, ten to 25 children aged

  4. Vectors expressing chimeric Japanese encephalitis dengue 2 viruses.

    Science.gov (United States)

    Wei, Y; Wang, S; Wang, X

    2014-01-01

    Vectors based on self-replicating RNAs (replicons) of flaviviruses are becoming powerful tool for expression of heterologous genes in mammalian cells and development of novel antiviral and anticancer vaccines. We constructed two vectors expressing chimeric viruses consisting of attenuated SA14-14-2 strain of Japanese encephalitis virus (JEV) in which the PrM/M-E genes were replaced fully or partially with those of dengue 2 virus (DENV-2). These vectors, named pJED2 and pJED2-1770 were transfected to BHK-21 cells and produced chimeric viruses JED2V and JED2-1770V, respectively. The chimeric viruses could be passaged in C6/36 but not BHK-21 cells. The chimeric viruses produced in C6/36 cells CPE 4-5 days after infection and RT-PCR, sequencing, immunofluorescence assay (IFA) and Western blot analysis confirmed the chimeric nature of produced viruses. The immunogenicity of chimeric viruses in mice was proved by detecting DENV-2 E protein-specific serum IgG antibodies with neutralization titer of 10. Successful preparation of infectious clones of chimeric JEV-DENV-2 viruses showed that JEV-based expression vectors are fully functional.

  5. Kinetics of dengue virus-specific serum immunoglobulin classes and subclasses correlate with clinical outcome of infection.

    NARCIS (Netherlands)

    P. Koraka (Penelope); C. Suharti (Catarina); T.E. Setiati (Tatty); A.T.A. Mairuhu; E.C.M. van Gorp (Eric); C.E. Hack (Erik); M. Juffrie; J. Sutaryo; G.M. van der Meer; J. Groen (Jan); A.D.M.E. Osterhaus (Albert)

    2001-01-01

    textabstractThe kinetics of dengue virus (DEN)-specific serum immunoglobulin classes (immunoglobulin M [IgM] and IgA) and subclasses (IgG1 to IgG4) were studied in patients suffering from dengue fever (DF), dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS). Serum samples from non-DEN f

  6. Dengue virus serotype 4 and chikungunya virus coinfection in a traveller returning from Luanda, Angola, January 2014.

    Science.gov (United States)

    Parreira, R; Centeno-Lima, S; Lopes, A; Portugal-Calisto, D; Constantino, A; Nina, J

    2014-03-13

    A concurrent dengue virus serotype 4 and chikungunya virus infection was detected in a woman in her early 50s returning to Portugal from Luanda, Angola, in January 2014. The clinical, laboratory and molecular findings, involving phylogenetic analyses of partial viral genomic sequences amplified by RT-PCR, are described. Although the circulation of both dengue and chikungunya viruses in Angola has been previously reported, to our knowledge this is the first time coinfection with both viruses has been detected there.

  7. Dengue virus-specific, human CD4+ CD8- cytotoxic T-cell clones: multiple patterns of virus cross-reactivity recognized by NS3-specific T-cell clones.

    OpenAIRE

    Kurane, I; Brinton, M.A.; Samson, A L; Ennis, F A

    1991-01-01

    Thirteen dengue virus-specific, cytotoxic CD4+ CD8- T-cell clones were established from a donor who was infected with dengue virus type 3. These clones were examined for virus specificity and human leukocyte antigen (HLA) restriction in cytotoxic assays. Six patterns of virus specificities were determined. Two serotype-specific clones recognized only dengue virus type 3. Two dengue virus subcomplex-specific clones recognized dengue virus types 2, 3, and 4, and one subcomplex-specific clone re...

  8. Nucleocapsid-like particles of dengue-2 virus enhance the immune response against a recombinant protein of dengue-4 virus.

    Science.gov (United States)

    Lazo, Laura; Gil, Lázaro; Lopez, Carlos; Valdes, Iris; Marcos, Ernesto; Alvarez, Mayling; Blanco, Aracelys; Romero, Yaremis; Falcon, Viviana; Guzmán, María G; Guillén, Gerardo; Hermida, Lisset

    2010-10-01

    In this study, we evaluate in mice a novel formulation containing nucleocapsid-like particles of dengue-2 virus (recNLP) co-immunized with a chimeric protein composed of the dengue-4 envelope domain III fused twice within the meningococcal P64k protein of Neisseria meningitidis (PD24). The animals receiving the PD24-recNLP mixture showed the highest levels of antiviral antibodies. Similar results were obtained for IFNγ secretion levels, indicating a functional Th1 cellular response. Consistently, the percentage of mice surviving after viral challenge was significantly higher for those immunized with the mixture than for those inoculated with PD24 protein alone. In addition, in vivo depletion experiments demonstrated the decisive role of CD4(+) and CD8(+) cells in the protection conferred by immunization with PD24-recNLP. In conclusion, this report demonstrates for the first time the adjuvant capacity of dengue-2 virus recNLP. Additionally, the evidence presented highlights the potential of these particles for enhancing the immune response against heterologous recombinant proteins.

  9. Longitudinal Analysis of Natural Killer Cells in Dengue Virus-Infected Patients in Comparison to Chikungunya and Chikungunya/Dengue Virus-Infected Patients.

    Directory of Open Access Journals (Sweden)

    Caroline Petitdemange

    2016-03-01

    Full Text Available Dengue virus (DENV is the most prominent arbovirus worldwide, causing major epidemics in South-East Asia, South America and Africa. In 2010, a major DENV-2 outbreak occurred in Gabon with cases of patients co-infected with chikungunya virus (CHIKV. Although the innate immune response is thought to be of primordial importance in the development and outcome of arbovirus-associated pathologies, our knowledge of the role of natural killer (NK cells during DENV-2 infection is in its infancy.We performed the first extensive comparative longitudinal characterization of NK cells in patients infected by DENV-2, CHIKV or both viruses. Hierarchical clustering and principal component analyses were performed to discriminate between CHIKV and DENV-2 infected patients.We observed that both activation and differentiation of NK cells are induced during the acute phase of infection by DENV-2 and CHIKV. Combinatorial analysis however, revealed that both arboviruses induced two different signatures of NK-cell responses, with CHIKV more associated with terminal differentiation, and DENV-2 with inhibitory KIRs. We show also that intracellular production of interferon-γ (IFN-γ by NK cells is strongly stimulated in acute DENV-2 infection, compared to CHIKV.Although specific differences were observed between CHIKV and DENV-2 infections, the significant remodeling of NK cell populations observed here suggests their potential roles in the control of both infections.

  10. Dynamics of interleukin-21 production during the clinical course of primary and secondary dengue virus infections.

    Science.gov (United States)

    Vivanco-Cid, H; Maldonado-Rentería, M J; Sánchez-Vargas, L A; Izaguirre-Hernández, I Y; Hernández-Flores, K G; Remes-Ruiz, R

    2014-09-01

    Previous studies have revealed the clinical relevance of pro-inflammatory cytokine production during dengue virus (DENV) infections. In this study, we evaluated the production of interleukin-21 (IL-21), a key soluble mediator mainly produced by CD4+ T cells. The aim of this study was to investigate the role of IL-21 production during the clinical course of primary and secondary DENV infections and the potential association of IL-21 serum levels with the disease pathogenesis. Blood samples from DENV-infected patients were collected on different days after the onset of symptoms. Patients were classified according to their phase of disease (acute vs. convalescent phases), the type of infection (primary vs. secondary), and the clinical severity of their disease (dengue fever (DF) vs. dengue hemorrhagic fever (DHF)). IL-21 levels were measured using a quantitative capture ELISA assay. The levels of IL-21 were significantly elevated in the disease group compared with the control group. IL-21 was detected in primary and secondary DENV infections, with a significantly higher concentration in the convalescent phase of primary infections. IL-21 levels were significantly higher in patients with secondary acute DHF infections when compared with those with secondary acute DF infection. There was a relationship between the elevated serum levels of IL-21 and the production of DENV-specific IgM and IgG antibodies. Taking together, our results show for the first time the involvement of IL-21 during the clinical course of DENV infections. We speculate that IL-21 may play a protective role in the context of the convalescent phase of primary infections and the acute phase of secondary infections.

  11. Emergence of New Lineage of Dengue virus 3 (genotype III in Lucknow, India

    Directory of Open Access Journals (Sweden)

    Sanjeev Tripathi

    2013-03-01

    Full Text Available Dengue has re-emerged as an important arboviral disease causing significant morbidity. It has become hyperendemic in the Indian subcontinent with all the four known dengue serotypes circulating. In the present study we have characterized dengue virus type 3 (DENV-3 circulating in Lucknow, Uttar Pradesh, India. Multiple sequence alignment and phylogenetic tree were constructed to determine the extent of genetic heterogeneity and phylogeny of the dengue virus isolated. Sequencing and phylogenetic analysis of the C-prM gene junction revealed the active circulation and persistence of a new lineage of DENV-3 (genotype III circulating in this region of India.

  12. Progress in the Identification of Dengue Virus Entry/Fusion Inhibitors

    Directory of Open Access Journals (Sweden)

    Carolina De La Guardia

    2014-01-01

    Full Text Available Dengue fever, a reemerging disease, is putting nearly 2.5 billion people at risk worldwide. The number of infections and the geographic extension of dengue fever infection have increased in the past decade. The disease is caused by the dengue virus, a flavivirus that uses mosquitos Aedes sp. as vectors. The disease has several clinical manifestations, from the mild cold-like illness to the more serious hemorrhagic dengue fever and dengue shock syndrome. Currently, there is no approved drug for the treatment of dengue disease or an effective vaccine to fight the virus. Therefore, the search for antivirals against dengue virus is an active field of research. As new possible receptors and biological pathways of the virus biology are discovered, new strategies are being undertaken to identify possible antiviral molecules. Several groups of researchers have targeted the initial step in the infection as a potential approach to interfere with the virus. The viral entry process is mediated by viral proteins and cellular receptor molecules that end up in the endocytosis of the virion, the fusion of both membranes, and the release of viral RNA in the cytoplasm. This review provides an overview of the targets and progress that has been made in the quest for dengue virus entry inhibitors.

  13. Dengue reporter virus particles for measuring neutralizing antibodies against each of the four dengue serotypes.

    Science.gov (United States)

    Mattia, Kimberly; Puffer, Bridget A; Williams, Katherine L; Gonzalez, Ritela; Murray, Meredith; Sluzas, Emily; Pagano, Dan; Ajith, Sandya; Bower, Megan; Berdougo, Eli; Harris, Eva; Doranz, Benjamin J

    2011-01-01

    The lack of reliable, high-throughput tools for characterizing anti-dengue virus (DENV) antibodies in large numbers of serum samples has been an obstacle in understanding the impact of neutralizing antibodies on disease progression and vaccine efficacy. A reporter system using pseudoinfectious DENV reporter virus particles (RVPs) was previously developed by others to facilitate the genetic manipulation and biological characterization of DENV virions. In the current study, we demonstrate the diagnostic utility of DENV RVPs for measuring neutralizing antibodies in human serum samples against all four DENV serotypes, with attention to the suitability of DENV RVPs for large-scale, long-term studies. DENV RVPs used against human sera yielded serotype-specific responses and reproducible neutralization titers that were in statistical agreement with Plaque Reduction Neutralization Test (PRNT) results. DENV RVPs were also used to measure neutralization titers against the four DENV serotypes in a panel of human sera from a clinical study of dengue patients. The high-throughput capability, stability, rapidity, and reproducibility of assays using DENV RVPs offer advantages for detecting immune responses that can be applied to large-scale clinical studies of DENV infection and vaccination.

  14. Dengue reporter virus particles for measuring neutralizing antibodies against each of the four dengue serotypes.

    Directory of Open Access Journals (Sweden)

    Kimberly Mattia

    Full Text Available The lack of reliable, high-throughput tools for characterizing anti-dengue virus (DENV antibodies in large numbers of serum samples has been an obstacle in understanding the impact of neutralizing antibodies on disease progression and vaccine efficacy. A reporter system using pseudoinfectious DENV reporter virus particles (RVPs was previously developed by others to facilitate the genetic manipulation and biological characterization of DENV virions. In the current study, we demonstrate the diagnostic utility of DENV RVPs for measuring neutralizing antibodies in human serum samples against all four DENV serotypes, with attention to the suitability of DENV RVPs for large-scale, long-term studies. DENV RVPs used against human sera yielded serotype-specific responses and reproducible neutralization titers that were in statistical agreement with Plaque Reduction Neutralization Test (PRNT results. DENV RVPs were also used to measure neutralization titers against the four DENV serotypes in a panel of human sera from a clinical study of dengue patients. The high-throughput capability, stability, rapidity, and reproducibility of assays using DENV RVPs offer advantages for detecting immune responses that can be applied to large-scale clinical studies of DENV infection and vaccination.

  15. Thrombocytopenia in Dengue: Interrelationship between Virus and the Imbalance between Coagulation and Fibrinolysis and Inflammatory Mediators.

    Science.gov (United States)

    de Azeredo, Elzinandes Leal; Monteiro, Robson Q; de-Oliveira Pinto, Luzia Maria

    2015-01-01

    Dengue is an infectious disease caused by dengue virus (DENV). In general, dengue is a self-limiting acute febrile illness followed by a phase of critical defervescence, in which patients may improve or progress to a severe form. Severe illness is characterized by hemodynamic disturbances, increased vascular permeability, hypovolemia, hypotension, and shock. Thrombocytopenia and platelet dysfunction are common in both cases and are related to the clinical outcome. Different mechanisms have been hypothesized to explain DENV-associated thrombocytopenia, including the suppression of bone marrow and the peripheral destruction of platelets. Studies have shown DENV-infected hematopoietic progenitors or bone marrow stromal cells. Moreover, anti-platelet antibodies would be involved in peripheral platelet destruction as platelets interact with endothelial cells, immune cells, and/or DENV. It is not yet clear whether platelets play a role in the viral spread. Here, we focus on the mechanisms of thrombocytopenia and platelet dysfunction in DENV infection. Because platelets participate in the inflammatory and immune response by promoting cytokine, chemokine, and inflammatory mediator secretion, their relevance as "immune-like effector cells" will be discussed. Finally, an implication for platelets in plasma leakage will be also regarded, as thrombocytopenia is associated with clinical outcome and higher mortality.

  16. Thrombocytopenia in Dengue: Interrelationship between Virus and the Imbalance between Coagulation and Fibrinolysis and Inflammatory Mediators

    Directory of Open Access Journals (Sweden)

    Elzinandes Leal de Azeredo

    2015-01-01

    Full Text Available Dengue is an infectious disease caused by dengue virus (DENV. In general, dengue is a self-limiting acute febrile illness followed by a phase of critical defervescence, in which patients may improve or progress to a severe form. Severe illness is characterized by hemodynamic disturbances, increased vascular permeability, hypovolemia, hypotension, and shock. Thrombocytopenia and platelet dysfunction are common in both cases and are related to the clinical outcome. Different mechanisms have been hypothesized to explain DENV-associated thrombocytopenia, including the suppression of bone marrow and the peripheral destruction of platelets. Studies have shown DENV-infected hematopoietic progenitors or bone marrow stromal cells. Moreover, anti-platelet antibodies would be involved in peripheral platelet destruction as platelets interact with endothelial cells, immune cells, and/or DENV. It is not yet clear whether platelets play a role in the viral spread. Here, we focus on the mechanisms of thrombocytopenia and platelet dysfunction in DENV infection. Because platelets participate in the inflammatory and immune response by promoting cytokine, chemokine, and inflammatory mediator secretion, their relevance as “immune-like effector cells” will be discussed. Finally, an implication for platelets in plasma leakage will be also regarded, as thrombocytopenia is associated with clinical outcome and higher mortality.

  17. Dengue virus type 3 in Brazil: a phylogenetic perspective

    Directory of Open Access Journals (Sweden)

    Josélio Maria Galvão de Araújo

    2009-05-01

    Full Text Available Circulation of a new dengue virus (DENV-3 genotype was recently described in Brazil and Colombia, but the precise classification of this genotype has been controversial. Here we perform phylogenetic and nucleotide-distance analyses of the envelope gene, which support the subdivision of DENV-3 strains into five distinct genotypes (GI to GV and confirm the classification of the new South American genotype as GV. The extremely low genetic distances between Brazilian GV strains and the prototype Philippines/L11423 GV strain isolated in 1956 raise important questions regarding the origin of GV in South America.

  18. Dengue: a trilogy of people, mosquitoes and the virus. Current epidemiology and pathogenesis in (non-)endemic settings

    NARCIS (Netherlands)

    Thai, K.T.D.

    2012-01-01

    Dengue consists of a spectrum of disease manifestations caused by four serotypes of Dengue virus, the most prevalent arthropod-borne virus affecting humans in the tropics and subtropics. The incidence of dengue and its geographical distribution have increased dramatically in the past 6 decades. Whil

  19. Field Evaluation of a Deployable RT-PCR Assay System for Real-Time Identification of Dengue Virus

    Science.gov (United States)

    2004-06-01

    strains of dengue serotypes 1-4, yellow fever, Japanese encephalitis, West Nile, and St. Louis encephalitis viruses as well as dengue virus infected...JA, Pyke A, Smith GA. Single rapid TaqMan fluorogenic probe based PCR assay that detects all four dengue serotypes . J Med Virol. 2002 April; 66(4

  20. Apropos: ‘Preliminary evaluation on the efficiency of the kit Platelia Dengue NS1 Ag-ELISA to detect dengue virus in dried Aedes aegypti: a potential tool to improve dengue surveillance’

    OpenAIRE

    Arya, Subhash C.; Agarwal, Nirmala

    2014-01-01

    Only simple, point-of-care, assay formats of the Platellia Dengue NS1 Ag-ELISA would be suitable to identify Dengue virus in Aedes aegypti mosquitoes in dengue-endemic areas lacking sophisticated laboratory infrastructure and trained laboratory personnel.

  1. Enhanced performance of an innovative dengue IgG/IgM rapid diagnostic test using an anti-dengue EDI monoclonal antibody and dengue virus antigen.

    Science.gov (United States)

    Lee, Jihoo; Kim, Young-Eun; Kim, Hak-Yong; Sinniah, Mangalam; Chong, Chom-Kyu; Song, Hyun-Ok

    2015-12-11

    High levels of anti-dengue IgM or IgG can be detected using numerous rapid diagnostic tests (RDTs). However, the sensitivity and specificity of these tests are reduced by changes in envelope glycoprotein antigenicity that inevitably occur in limited expression systems. A novel RDT was designed to enhance diagnostic sensitivity. Dengue viruses cultured in animal cells were used as antigens to retain the native viral coat protein. Monoclonal antibodies (mAbs) were then developed, for the first time, against domain I of envelope glycoprotein (EDI). The anti-dengue EDI mAb was employed as a capturer, and EDII and EDIII, which are mainly involved in the induction of neutralizing antibodies in patients, were fully available to bind to anti-dengue IgM or IgG in patients. A one-way automatic blood separation device prevented reverse migration of plasma and maximize the capture of anti-dengue antibodies at the test lines. A clinical evaluation in the field proved that the novel RDT (sensitivities of 96.5% and 96.7% for anti-dengue IgM and IgG) is more effective in detecting anti-dengue antibodies than two major commercial tests (sensitivities of 54.8% and 82% for SD BIOLINE; 50.4% and 75.3% for PanBio). The innovative format of RDT can be applied to other infectious viral diseases.

  2. Multiple specificities in the murine CD4+ and CD8+ T-cell response to dengue virus.

    OpenAIRE

    Rothman, A. L.; Kurane, I; Ennis, F A

    1996-01-01

    The target epitopes, serotype specificity, and cytolytic function of dengue virus-specific T cells may influence their theoretical roles in protection against secondary infection as well as the immunopathogenesis of dengue hemorrhagic fever. To study these factors in an experimental system, we isolated dengue virus-specific CD4+ and CD8+ T-cell clones from dengue-2 virus-immunized BALB/c mice. The T-cell response to dengue virus in this mouse strain was heterogeneous; we identified at least f...

  3. Evaluation of commercially available diagnostic tests for the detection of dengue virus NS1 antigen and anti-dengue virus IgM antibody.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Hunsperger

    2014-10-01

    Full Text Available Commercially available diagnostic test kits for detection of dengue virus (DENV non-structural protein 1 (NS1 and anti-DENV IgM were evaluated for their sensitivity and specificity and other performance characteristics by a diagnostic laboratory network developed by World Health Organization (WHO, the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR and the Pediatric Dengue Vaccine Initiative (PDVI. Each network laboratory contributed characterized serum specimens for the panels used in the evaluation. Microplate enzyme-linked immunosorbent assay (ELISA and rapid diagnostic test (RDT formats were represented by the kits. Each ELISA was evaluated by 2 laboratories and RDTs were evaluated by at least 3 laboratories. The reference tests for IgM anti-DENV were laboratory developed assays produced by the Armed Forces Research Institute for Medical Science (AFRIMS and the Centers for Disease Control and Prevention (CDC, and the NS1 reference test was reverse transcriptase polymerase chain reaction (RT-PCR. Results were analyzed to determine sensitivity, specificity, inter-laboratory and inter-reader agreement, lot-to-lot variation and ease-of-use. NS1 ELISA sensitivity was 60-75% and specificity 71-80%; NS1 RDT sensitivity was 38-71% and specificity 76-80%; the IgM anti-DENV RDTs sensitivity was 30-96%, with a specificity of 86-92%, and IgM anti-DENV ELISA sensitivity was 96-98% and specificity 78-91%. NS1 tests were generally more sensitive in specimens from the acute phase of dengue and in primary DENV infection, whereas IgM anti-DENV tests were less sensitive in secondary DENV infections. The reproducibility of the NS1 RDTs ranged from 92-99% and the IgM anti-DENV RDTs from 88-94%.

  4. Evaluation of Commercially Available Diagnostic Tests for the Detection of Dengue Virus NS1 Antigen and Anti-Dengue Virus IgM Antibody

    Science.gov (United States)

    Hunsperger, Elizabeth A.; Yoksan, Sutee; Buchy, Philippe; Nguyen, Vinh Chau; Sekaran, Shamala Devi; Enria, Delia A.; Vazquez, Susana; Cartozian, Elizabeth; Pelegrino, Jose L.; Artsob, Harvey; Guzman, Maria G.; Olliaro, Piero; Zwang, Julien; Guillerm, Martine; Kliks, Susie; Halstead, Scott; Peeling, Rosanna W.; Margolis, Harold S.

    2014-01-01

    Commercially available diagnostic test kits for detection of dengue virus (DENV) non-structural protein 1 (NS1) and anti-DENV IgM were evaluated for their sensitivity and specificity and other performance characteristics by a diagnostic laboratory network developed by World Health Organization (WHO), the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR) and the Pediatric Dengue Vaccine Initiative (PDVI). Each network laboratory contributed characterized serum specimens for the panels used in the evaluation. Microplate enzyme-linked immunosorbent assay (ELISA) and rapid diagnostic test (RDT formats) were represented by the kits. Each ELISA was evaluated by 2 laboratories and RDTs were evaluated by at least 3 laboratories. The reference tests for IgM anti-DENV were laboratory developed assays produced by the Armed Forces Research Institute for Medical Science (AFRIMS) and the Centers for Disease Control and Prevention (CDC), and the NS1 reference test was reverse transcriptase polymerase chain reaction (RT-PCR). Results were analyzed to determine sensitivity, specificity, inter-laboratory and inter-reader agreement, lot-to-lot variation and ease-of-use. NS1 ELISA sensitivity was 60–75% and specificity 71–80%; NS1 RDT sensitivity was 38–71% and specificity 76–80%; the IgM anti-DENV RDTs sensitivity was 30–96%, with a specificity of 86–92%, and IgM anti-DENV ELISA sensitivity was 96–98% and specificity 78–91%. NS1 tests were generally more sensitive in specimens from the acute phase of dengue and in primary DENV infection, whereas IgM anti-DENV tests were less sensitive in secondary DENV infections. The reproducibility of the NS1 RDTs ranged from 92-99% and the IgM anti-DENV RDTs from 88–94%. PMID:25330157

  5. Identification of new protein interactions between dengue fever virus and its hosts, human and mosquito.

    Directory of Open Access Journals (Sweden)

    Dumrong Mairiang

    Full Text Available The four divergent serotypes of dengue virus are the causative agents of dengue fever, dengue hemorrhagic fever and dengue shock syndrome. About two-fifths of the world's population live in areas where dengue is prevalent, and thousands of deaths are caused by the viruses every year. Dengue virus is transmitted from one person to another primarily by the yellow fever mosquito, Aedes aegypti. Recent studies have begun to define how the dengue viral proteins interact with host proteins to mediate viral replication and pathogenesis. A combined analysis of these studies, however, suggests that many virus-host protein interactions remain to be identified, especially for the mosquito host. In this study, we used high-throughput yeast two-hybrid screening to identify mosquito and human proteins that physically interact with dengue proteins. We tested each identified host protein against the proteins from all four serotypes of dengue to identify interactions that are conserved across serotypes. We further confirmed many of the interactions using co-affinity purification assays. As in other large-scale screens, we identified some previously detected interactions and many new ones, moving us closer to a complete host - dengue protein interactome. To help summarize and prioritize the data for further study, we combined our interactions with other published data and identified a subset of the host-dengue interactions that are now supported by multiple forms of evidence. These data should be useful for understanding the interplay between dengue and its hosts and may provide candidates for drug targets and vector control strategies.

  6. Epitope Mapping of Dengue-Virus-Enhancing Monoclonal-Antibody Using Phage Display Peptide Library

    OpenAIRE

    Chung-I Rai; Huan-Yao Lei; Yee-Shin Lin; Hsiao-Sheng Liu; Shun-Hua Chen; Lien-Cheng Chen; Trai-Ming Yeh

    2008-01-01

    The Antibody-Dependent Enhancement (ADE) hypothesis has been proposed to explain why more severe manifestations of Dengue Hemorrhagic Fever and Dengue Shock Syndrome (DHF/DSS) occur predominantly during secondary infections of Dengue Virus (DV) with different serotypes. However, the epitopes recognized by these enhancing antibodies are unclear. Recently, anti-pre-M monoclonal antibody (mAb 70-21), which recognized all DV serotypes without neutralizing activity, were generated and demonstrated...

  7. Dengue Virus NS1 Disrupts the Endothelial Glycocalyx, Leading to Hyperpermeability

    OpenAIRE

    Henry Puerta-Guardo; Dustin R Glasner; Eva Harris

    2016-01-01

    Dengue is the most prevalent arboviral disease in humans and a major public health problem worldwide. Systemic plasma leakage, leading to hypovolemic shock and potentially fatal complications, is a critical determinant of dengue severity. Recently, we and others described a novel pathogenic effect of secreted dengue virus (DENV) non-structural protein 1 (NS1) in triggering hyperpermeability of human endothelial cells in vitro and systemic vascular leakage in vivo. NS1 was shown to activate to...

  8. Prevalence of dengue and chikungunya virus infections in north-eastern Tanzania

    DEFF Research Database (Denmark)

    Kajeguka, Debora C; Kaaya, Robert D; Mwakalinga, Steven;

    2016-01-01

    BACKGROUND: In spite of increasing reports of dengue and chikungunya activity in Tanzania, limited research has been done to document the general epidemiology of dengue and chikungunya in the country. This study aimed at determining the sero-prevalence and prevalence of acute infections of dengue......-like symptoms at health facilities at Bondo dispensary (Bondo, Tanga), Hai hospital (Hai, Kilimanjaro) and TPC hospital (Lower Moshi). Participants who were malaria negative using rapid diagnostic tests (mRDT) were screened for sero-positivity towards dengue and chikungunya Immunoglobulin G and M (IgG and Ig......M) using ELISA-based kits. Participants with specific symptoms defined as probable dengue and/or chikungunya by WHO (fever and various combinations of symptoms such as headache, rash, nausea/vomit, and joint pain) were further screened for acute dengue and chikungunya infections by PCR. RESULTS: Out...

  9. Novel anti-dengue monoclonal antibody recognizing conformational structure of the prM-E heterodimeric complex of dengue virus.

    Science.gov (United States)

    Puttikhunt, Chunya; Keelapang, Poonsook; Khemnu, Nuanpan; Sittisombut, Nopporn; Kasinrerk, Watchara; Malasit, Prida

    2008-01-01

    An interaction between the premembrane (prM) and envelope (E) glycoproteins as prM-E heterodimer is required for proper folding and transport of E during the formation and release of new flaviviral progeny. More evidence, however, is needed to confirm this interaction of prM and E during dengue virus replication. In this study, 2E11, a mouse monoclonal antibody (Mab) that specifically recognizes dengue prM-E heterodimeric complex in either intracellular or secreted dengue virions, was generated and characterized. In immunofluorescence and immuno-pull down assays, the Mab 2E11 recognized an epitope present in 293T transfectants that co-expressed prM and the full-length form of E in cis and in trans, but it failed to react with prM or E protein expressed individually. The reactivity of Mab 2E11 was diminished in transfected cells that co-express prM together with a truncated form of E lacking the 84-residue stretch at the C-terminal transmembrane region, presumably essential for prM and E interaction. The Mab 2E11 described in this study is a novel Mab with a unique capability in detecting the conformational structure of prM-E heterodimeric complex of dengue virus. It will be a new biological tool for identification and characterization of dengue prM-E heterodimer as well as virus maturation and export.

  10. Incidence of dengue virus infection among Japanese travellers, 2006 to 2010

    Directory of Open Access Journals (Sweden)

    Yuki Tada

    2012-06-01

    Full Text Available Introduction: Dengue continues to be a global public health concern. In Japan, although dengue cases are currently seen only among travellers returning from endemic areas, the number of reported cases is rising according to the national case-based surveillance system. We evaluated the characteristics of dengue cases imported into Japan and the relationship between the incidence of infection and season of travel to popular destinations.Methods: Dengue cases reported to the national surveillance system were retrospectively examined. The number of reported cases per number of Japanese travellers to a dengue-endemic country was calculated to estimate the country-specific incidence of imported dengue virus infection. The incidence of dengue infection among Japanese travellers was compared between dengue high season and low season in each country using relative risk (RR and associated 95% confidence intervals (CI.Results: Among 540 Japanese residents who were reported as dengue cases from 2006 to 2010, the majority had travelled to Indonesia, India, the Philippines and Thailand. The RR of dengue infection among Japanese travellers during dengue high season versus low season was 4.92 (95% CI: 3.01–8.04 for the Philippines, 2.76 (95% CI: 1.67–4.54 for Thailand and 0.37 (95% CI: 0.15–0.92 for Indonesia.Discussion: Overall, higher incidence of imported cases appeared to be related to historic dengue high seasons. Travellers planning to visit dengue-endemic countries should be aware of historic dengue seasonality and the current dengue situation.

  11. Dengue Fever Testing

    Science.gov (United States)

    ... limited. Home Visit Global Sites Search Help? Dengue Fever Testing Share this page: Was this page helpful? Also known as: Dengue Fever Antibodies; Dengue Fever Virus Formal name: Dengue Antibodies ( ...

  12. The spatial dynamics of dengue virus in Kamphaeng Phet, Thailand.

    Directory of Open Access Journals (Sweden)

    Piraya Bhoomiboonchoo

    2014-09-01

    Full Text Available Dengue is endemic to the rural province of Kamphaeng Phet, Northern Thailand. A decade of prospective cohort studies has provided important insights into the dengue viruses and their generated disease. However, as elsewhere, spatial dynamics of the pathogen remain poorly understood. In particular, the spatial scale of transmission and the scale of clustering are poorly characterized. This information is critical for effective deployment of spatially targeted interventions and for understanding the mechanisms that drive the dispersal of the virus.We geocoded the home locations of 4,768 confirmed dengue cases admitted to the main hospital in Kamphaeng Phet province between 1994 and 2008. We used the phi clustering statistic to characterize short-term spatial dependence between cases. Further, to see if clustering of cases led to similar temporal patterns of disease across villages, we calculated the correlation in the long-term epidemic curves between communities. We found that cases were 2.9 times (95% confidence interval 2.7-3.2 more likely to live in the same village and be infected within the same month than expected given the underlying spatial and temporal distribution of cases. This fell to 1.4 times (1.2-1.7 for individuals living in villages 1 km apart. Significant clustering was observed up to 5 km. We found a steadily decreasing trend in the correlation in epidemics curves by distance: communities separated by up to 5 km had a mean correlation of 0.28 falling to 0.16 for communities separated between 20 km and 25 km. A potential explanation for these patterns is a role for human movement in spreading the pathogen between communities. Gravity style models, which attempt to capture population movement, outperformed competing models in describing the observed correlations.There exists significant short-term clustering of cases within individual villages. Effective spatially and temporally targeted interventions deployed within villages may

  13. Vigilancia del dengue basada en el laboratorio: diferencias en el número de casos y virus aislados según la recolección del suero y la prueba serológica

    Directory of Open Access Journals (Sweden)

    Luis Ángel Villar

    2005-06-01

    Full Text Available Background: Dengue control measures depend on the laboratory-based surveillance data. In this study was investigated the differences in dengue cases and viruses isolated in according with surveillance strategy. Study design and methods: Two surveillance strategies were analyzed in this study. First (Local Surveillance System: single serum sample (acute or convalescent was collected from 337 dengue suspected cases and then kept at 4oC. IgM antibodies were detected using UMELISA DENGUE kit (IPK, Cuba, and serotypes identification was performed by viral isolation attempts in C6/36. Second: paired serum sample were collected from 318 dengue suspected cases and then kept at -70 ºC. IgM antibodies were detected using MAC-ELISA test and virus isolation as above. Some paired sera analyzed by MAC-ELISA were processed by “Dengue IgM-capture ELISA” kit (PANBIO and “IgM*ELISA anti-dengue” (IPK, Cuba. Results: More IgM+ dengue cases were detected by the first than second strategy using acute or convalescent serum: 61.1 vs 22% (p<0.001 y 86.8 vs 49.3% (p<0.001, respectively. Dengue diagnosis by MAC-ELISA was concordant in 85% (K=0.29 respect to UM-ELISA, but 100% (K=1 and 90.4% (K=0.84 respect to “IgM ELISA anti-dengue” and “Dengue IgM-capture ELISA” kits. Differences in dengue cases detected by the second strategy were found when serological result with single acute or paired samples was compared: 70 (22% vs 155 (48.7% (p<0.001. Dengue virus was isolated more frequently from sera kept at -70 ºC than those kept at 4 ºC: 17.8% vs. 4.7% (p<0.001. All virus serotypes were isolated. The UMELISA DENGUE test specificity and relationship between impact dengue surveillance and implemented strategy are analyzed. Conclusions: The specificity of UMELISA DENGUE test require to be evaluated by the high frequency of dengue in suspected cases. Serum paired analyzes in dengue surveillance is necessary to obtain reliable information.

  14. Infection of Mosquito Cells (C6/36) by Dengue-2 Virus Interferes with Subsequent Infection by Yellow Fever Virus.

    Science.gov (United States)

    Abrao, Emiliana Pereira; da Fonseca, Benedito Antônio Lopes

    2016-02-01

    Dengue is one of the most important diseases caused by arboviruses in the world. Yellow fever is another arthropod-borne disease of great importance to public health that is endemic to tropical regions of Africa and the Americas. Both yellow fever and dengue viruses are flaviviruses transmitted by Aedes aegypti mosquitoes, and then, it is reasonable to consider that in a given moment, mosquito cells could be coinfected by both viruses. Therefore, we decided to evaluate if sequential infections of dengue and yellow fever viruses (and vice-versa) in mosquito cells could affect the virus replication patterns. Using immunofluorescence and real-time PCR-based replication assays in Aedes albopictus C6/36 cells with single or sequential infections with both viruses, we demonstrated the occurrence of viral interference, also called superinfection exclusion, between these two viruses. Our results show that this interference pattern is particularly evident when cells were first infected with dengue virus and subsequently with yellow fever virus (YFV). Reduction in dengue virus replication, although to a lower extent, was also observed when C6/36 cells were initially infected with YFV followed by dengue virus infection. Although the importance that these findings have on nature is unknown, this study provides evidence, at the cellular level, of the occurrence of replication interference between dengue and yellow fever viruses and raises the question if superinfection exclusion could be a possible explanation, at least partially, for the reported lack of urban yellow fever occurrence in regions where a high level of dengue transmission occurs.

  15. Intracellular cytokine production by dengue virus-specific T cells correlates with subclinical secondary infection.

    Science.gov (United States)

    Hatch, Steven; Endy, Tim P; Thomas, Stephen; Mathew, Anuja; Potts, James; Pazoles, Pamela; Libraty, Daniel H; Gibbons, Robert; Rothman, Alan L

    2011-05-01

    The pathophysiology of dengue virus infection remains poorly understood, although secondary infection is strongly associated with more severe disease. In the present study, we performed a nested, case-control study comparing the responses of pre-illness peripheral blood mononuclear cells between children who would subsequently develop either subclinical or symptomatic secondary infection 6-11 months after the baseline blood samples were obtained and frozen. We analyzed intracellular cytokine production by CD4(+) and CD8(+) cells in response to stimulation with dengue antigen. We found higher frequencies of dengue virus-specific TNFα, IFNγ-, and IL-2-producing T cells among schoolchildren who subsequently developed subclinical infection, compared with those who developed symptomatic secondary dengue virus infection. Although other studies have correlated immune responses during secondary infection with severity of disease, to our knowledge this is the first study to demonstrate a pre-infection dengue-specific immune response that correlates specifically with a subclinical secondary infection.

  16. Dengue virus compartmentalization during antibody-enhanced infection

    Science.gov (United States)

    Ong, Eugenia Z.; Zhang, Summer L.; Tan, Hwee Cheng; Gan, Esther S.; Chan, Kuan Rong; Ooi, Eng Eong

    2017-01-01

    Secondary infection with a heterologous dengue virus (DENV) serotype increases the risk of severe dengue, through a process termed antibody-dependent enhancement (ADE). During ADE, DENV is opsonized with non- or sub-neutralizing antibody levels that augment entry into monocytes and dendritic cells through Fc-gamma receptors (FcγRs). We previously reported that co-ligation of leukocyte immunoglobulin-like receptor-B1 (LILRB1) by antibody-opsonized DENV led to recruitment of SH2 domain-containing phosphatase-1 (SHP-1) to dephosphorylate spleen tyrosine kinase (Syk) and reduce interferon stimulated gene induction. Here, we show that LILRB1 also signals through SHP-1 to attenuate the otherwise rapid acidification for lysosomal enzyme activation following FcγR-mediated uptake of DENV. Reduced or slower trafficking of antibody-opsonized DENV to lytic phagolysosomal compartments, demonstrates how co-ligation of LILRB1 also permits DENV to overcome a cell-autonomous immune response, enhancing intracellular survival of DENV. Our findings provide insights on how antiviral drugs that modify phagosome acidification should be used for viruses such as DENV. PMID:28084461

  17. Membranotropic regions of the dengue virus prM protein.

    Science.gov (United States)

    Nemésio, Henrique; Villalaín, José

    2014-08-19

    The Dengue virus (DENV) prM protein consists of two moieties, the pr and M domains. Apart from preventing the premature fusion activity of the DENV E protein, prM has several other unknown biological roles, displaying both protein-protein and membrane-protein interactions. Although the prM protein is an essential component of the DENV viral cycle, little is known about its biological functions and what regions of this protein are responsible for said functions. By performing an exhaustive study of membrane rupture induced by a prM peptide library on simple and complex model membranes as well as their ability to modulate the phospholipid phase transitions of 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine and 1,2-dimyristoyl-sn-glycero-3-[phospho-rac-glycerol], we identified six membranotropic regions on the prM protein. Apart from the previously identified two transmembrane segments of the protein, one of these regions probably interacts with the fusion E protein and another one, the stem segment, would interact with the membrane modulating its structure. These data will help us understand the molecular mechanism of viral entry and morphogenesis, allow the identification of new targets for the treatment of Dengue virus infection, and make possible the future development of DENV entry inhibitors.

  18. Meta-Analysis of Dengue Severity during Infection by Different Dengue Virus Serotypes in Primary and Secondary Infections.

    Directory of Open Access Journals (Sweden)

    Kuan-Meng Soo

    Full Text Available Dengue virus (DENV infection is currently a major cause of morbidity and mortality in the world; it has become more common and virulent over the past half-century and has gained much attention. Thus, this review compared the percentage of severe cases of both primary and secondary infections with different serotypes of dengue virus.Data related to the number of cases involving dengue fever (DF, dengue hemorrhagic fever (DHF, dengue shock syndrome (DSS or severe dengue infections caused by different serotypes of dengue virus were obtained by using the SCOPUS, the PUBMED and the OVID search engines with the keywords "(dengue* OR dengue virus* AND (severe dengue* OR severity of illness index* OR severity* OR DF* OR DHF* OR DSS* AND (serotypes* OR serogroup*", according to the MESH terms suggested by PUBMED and OVID.Approximately 31 studies encompassing 15,741 cases reporting on the dengue serotypes together with their severity were obtained, and meta-analysis was carried out to analyze the data. This study found that DENV-3 from the Southeast Asia (SEA region displayed the greatest percentage of severe cases in primary infection (95% confidence interval (CI, 31.22-53.67, 9 studies, n = 598, I2 = 71.53%, whereas DENV-2, DENV-3, and DENV-4 from the SEA region, as well as DENV-2 and DENV-3 from non-SEA regions, exhibited the greatest percentage of severe cases in secondary infection (95% CI, 11.64-80.89, 4-14 studies, n = 668-3,149, I2 = 14.77-96.20%. Moreover, DENV-2 and DENV-4 from the SEA region had been found to be more highly associated with dengue shock syndrome (DSS (95% CI, 10.47-40.24, 5-8 studies, n = 642-2,530, I2 = 76.93-97.70%, while DENV-3 and DENV-4 from the SEA region were found to be more highly associated with dengue hemorrhagic fever (DHF (95% CI, 31.86-54.58, 9 studies, n = 674-2,278, I2 = 55.74-88.47%, according to the 1997 WHO dengue classification. Finally, DENV-2 and DENV-4 from the SEA region were discovered to be more highly

  19. Wild dengue virus types 1, 2 and 3 viremia in rhesus monkeys.

    Science.gov (United States)

    Freire, M S; Marchevsky, R S; Almeida, L F C; Yamamura, A M Y; Caride, E C; Brindeiro, P A; Motta, M C A; Nogueira, R M R; Kubelka, C F; Bonaldo, M C; Galler, R

    2007-05-01

    Among the flaviviruses, dengue, with its four serotypes, has spread throughout the tropics. The most advanced vaccines developed so far include live attenuated viruses, which have been tested in humans but none has been licensed. Preclinical testing of dengue vaccine candidates is performed initially in mice and in nonhuman primates. In the latter the main criteria used to assay protection are neutralizing antibodies elicited by the vaccine candidate and the magnitude and duration of peripheral viremia upon challenge of previously immunized animals. Towards the identification of wild-type viruses that could be used in challenge experiments a total of 31 rhesus monkeys were inoculated subcutaneously of wild dengue types 1, 2, and 3 viruses. The viremia caused by the different viruses was variable but it was possible to identify dengue viruses useful as challenge strains.

  20. Wild dengue virus types 1, 2 and 3 viremia in rhesus monkeys

    Directory of Open Access Journals (Sweden)

    MS Freire

    2007-03-01

    Full Text Available Among the flaviviruses, dengue, with its four serotypes, has spread throughout the tropics. The most advanced vaccines developed so far include live attenuated viruses, which have been tested in humans but none has been licensed. Preclinical testing of dengue vaccine candidates is performed initially in mice and in nonhuman primates. In the latter the main criteria used to assay protection are neutralizing antibodies elicited by the vaccine candidate and the magnitude and duration of peripheral viremia upon challenge of previously immunized animals. Towards the identification of wild-type viruses that could be used in challenge experiments a total of 31 rhesus monkeys were inoculated subcutaneously of wild dengue types 1, 2, and 3 viruses. The viremia caused by the different viruses was variable but it was possible to identify dengue viruses useful as challenge strains.

  1. Identification of novel target sites and an inhibitor of the dengue virus E protein

    Science.gov (United States)

    Yennamalli, Ragothaman; Subbarao, Naidu; Kampmann, Thorsten; McGeary, Ross P.; Young, Paul R.; Kobe, Bostjan

    2009-06-01

    Dengue and related flaviviruses represent a significant global health threat. The envelope glycoprotein E mediates virus attachment to a host cell and the subsequent fusion of viral and host cell membranes. The fusion process is driven by conformational changes in the E protein and is an essential step in the virus life cycle. In this study, we analyzed the pre-fusion and post-fusion structures of the dengue virus E protein to identify potential novel sites that could bind small molecules, which could interfere with the conformational transitions that mediate the fusion process. We used an in silico virtual screening approach combining three different docking algorithms (DOCK, GOLD and FlexX) to identify compounds that are likely to bind to these sites. Seven structurally diverse molecules were selected to test experimentally for inhibition of dengue virus propagation. The best compound showed an IC50 in the micromolar range against dengue virus type 2.

  2. Aedes aegypti D7 Saliva Protein Inhibits Dengue Virus Infection

    Science.gov (United States)

    Conway, Michael J.; Londono-Renteria, Berlin; Troupin, Andrea; Watson, Alan M.; Klimstra, William B.; Fikrig, Erol; Colpitts, Tonya M.

    2016-01-01

    Aedes aegypti is the primary vector of several medically relevant arboviruses including dengue virus (DENV) types 1–4. Ae. aegypti transmits DENV by inoculating virus-infected saliva into host skin during probing and feeding. Ae. aegypti saliva contains over one hundred unique proteins and these proteins have diverse functions, including facilitating blood feeding. Previously, we showed that Ae. aegypti salivary gland extracts (SGEs) enhanced dissemination of DENV to draining lymph nodes. In contrast, HPLC-fractionation revealed that some SGE components inhibited infection. Here, we show that D7 proteins are enriched in HPLC fractions that are inhibitory to DENV infection, and that recombinant D7 protein can inhibit DENV infection in vitro and in vivo. Further, binding assays indicate that D7 protein can directly interact with DENV virions and recombinant DENV envelope protein. These data reveal a novel role for D7 proteins, which inhibits arbovirus transmission to vertebrates through a direct interaction with virions. PMID:27632170

  3. Meningitis Associated with Simultaneous Infection by Multiple Dengue Virus Serotypes in Children, Brazil

    Science.gov (United States)

    Marinho, Paula Eillanny Silva; Bretas de Oliveira, Danilo; Candiani, Talitah Michel Sanchez; Crispim, Ana Paula Correia; Alvarenga, Pedro Paulo Martins; Castro, Fabrizia Cristina dos Santos; Abrahão, Jonatas Santos; Rios, Maria; Coimbra, Roney Santos

    2017-01-01

    To determine the causes of viral meningitis, we analyzed 22 cerebrospinal fluid samples collected during the 2014–2015 dengue epidemics in Brazil. We identified 3 serotypes of dengue virus (DENV-1, -2, and -3), as well as co-infection with 2 or 3 serotypes. We also detected the Asian II genotype of DENV-2. PMID:27983492

  4. On the modelling and analysis of the regulatory network of dengue virus pathogenesis and clearance

    NARCIS (Netherlands)

    Aslam, Babar; Ahmad, Jamil; Ali, Amjad; Paracha, Rehan Zafar; Tareen, Samar Hayat Khan; Niazi, Umar; Saeed, Tariq

    2014-01-01

    Dengue virus can ignite both protective and pathogenic responses in human. The pathogenesis is related with modified functioning of our immune system during infection. Pattern recognition receptors like Toll like receptor 3 is vital for the induction of innate immunity in case of Dengue infection. T

  5. Travel-related Dengue Virus Infection, the Netherlands, 2006-2007

    NARCIS (Netherlands)

    G.G.G. Baaten; G.J.B. Sonder; H.L. Zaaijer; T. van Gool; J.A.P.C.M. Kint; A. van den Hoek

    2011-01-01

    To assess the incidence of and risk factors for clinical and subclinical dengue virus (DENV) infection, we prospectively studied 1,207 adult short-term travelers from the Netherlands to dengue-endemic areas. Participants donated blood samples for serologic testing before and after travel. Blood samp

  6. Antibodies against the Envelope Glycoprotein Promote Infectivity of Immature Dengue Virus Serotype 2

    NARCIS (Netherlands)

    Voorham, Julia M. da Silva; Rodenhuis-Zybert, Izabela A.; Nunez, Nilda Vanesa Ayala; Colpitts, Tonya M.; van der Ende-Metselaar, Heidi; Fikrig, Erol; Diamond, Michael S.; Wilschut, Jan; Smit, Jolanda M.

    2012-01-01

    Cross-reactive dengue virus (DENV) antibodies directed against the envelope (E) and precursor membrane (prM) proteins are believed to contribute to the development of severe dengue disease by facilitating antibody-dependent enhancement of infection. We and others recently demonstrated that anti-prM

  7. NK cells during dengue disease and their recognition of dengue virus-infected cells

    Directory of Open Access Journals (Sweden)

    Davis Alexander Beltrán

    2014-05-01

    Full Text Available The innate immune response, in addition to the B and T cell response, plays a role in protection against dengue virus (DENV infection and the degree of disease severity. Early activation of NK cells and type-I interferon-dependent immunity may be important in limiting viral replication during the early stages of DENV infection and thus reducing subsequent pathogenesis. NK cells may also produce cytokines that reduce inflammation and tissue injury. On the other hand, NK cells are also capable of inducing liver injury at early-time points of DENV infection. In vitro, NK cells can kill antibody-coated DENV-infected cells through antibody-dependent cell-mediated cytotoxicity (ADCC. In additional, NK cells may directly recognize DENV-infected cells through their activating receptors, although the increase in HLA class I expression may allow infected cells to escape the NK response. Recently, genome-wide association studies (GWAS have shown an association between MICB and MICA, which encode ligands of the activating NK receptor NKG2D, and dengue disease outcome. This review focuses on recognition of DENV-infected cells by NK cells and on the regulation of expression of NK cell ligands by DENV.

  8. Development of dengue virus replicons expressing HIV-1 gp120 and other heterologous genes: a potential future tool for dual vaccination against dengue virus and HIV

    Directory of Open Access Journals (Sweden)

    Dayton Andrew I

    2001-11-01

    Full Text Available Abstract Background Toward the goals of providing an additional vector to add to the armamentarium available to HIV vaccinologists and of creating a bivalent vaccine effective against dengue virus and HIV, we have attempted to create vectors which express dengue virus non-structural proteins and HIV immunogens. Previously we reported the successful construction of dengue virus replicons which lack structural genes necessary for virion release and spreading infection in culture but which can replicate intracellularly and abundantly produce dengue non-structural proteins. Here we attempted to express heterologous genetic material from these replicons. Results We cloned into a Δpre-M/E dengue virus replicon genes for either green fluorescent protein (GFP, HIV gp160 or HIV gp120 and tested the ability of these constructs to express dengue virus proteins as well as the heterologous proteins in tissue culture after transfection of replicon RNA. Conclusions Heterologous proteins were readily expressed from these constructs. GFP and gp120 demonstrated minimal or no toxicity. Gp160 expressing replicons were found to express proteins abundantly at 36 hours post transfection, but after 50 hrs of transfection, few replicon positive cells could be found despite the presence of cellular debris positive for replicon proteins. This suggested that gp160 expressed from dengue virus replicons is considerably more toxic than either GFP or gp120. The successful expression of heterologous proteins, including HIV gp120 for long periods in culture suggests this vector system may be useful as a vaccine vector, given appropriate delivery methods.

  9. Dengue Fever/Dengue Haemorrhagic Fever : Case Management

    OpenAIRE

    Nimmannitya, Suchitra

    1995-01-01

    Dengue infections caused by the four antigenically distinct dengue virus serotypes (dengue virus 1, dengue virus 2, dengue virus 3, dengue virus 4) of the family Flavivindae, are the most important arbovirus disease in man, both in terms of morbidity and mortality. The infection is transmitted from man to man by Aedes mosquitoes. Since 1956, dengue virus infection has resulted in more than 3 million hospital admissions and more than 50,000 deaths in Southeast Asia, Western Pacific countries, ...

  10. Primary dengue haemorrhagic fever in patients from northeast of Brazil is associated with high levels of interferon-β during acute phase

    Science.gov (United States)

    Oliveira, Renato Antônio dos Santos; da Silva, Mayara Marques Carneiro; Calzavara-Silva, Carlos Eduardo; Silva, Ana Maria; Cordeiro, Marli Tenório; de Moura, Patrícia Muniz Mendes Freire; Baptista, Paulo Neves; Marques, Ernesto Torres de Azevedo; Gil, Laura Helena Vega Gonzales

    2016-01-01

    Dengue is an acute febrile disease caused by the mosquito-borne dengue virus (DENV) that according to clinical manifestations can be classified as asymptomatic, mild or severe dengue. Severe dengue cases have been associated with an unbalanced immune response characterised by an over secretion of inflammatory cytokines. In the present study we measured type I interferon (IFN-I) transcript and circulating levels in primary and secondary DENV infected patients. We observed that dengue fever (DF) and dengue haemorrhagic fever (DHF) patients express IFN-I differently. While DF and DHF patients express interferon-α similarly (52,71 ± 7,40 and 49,05 ± 7,70, respectively), IFN- β were associated with primary DHF patients. On the other hand, secondary DHF patients were not able to secrete large amounts of IFN- β which in turn may have influenced the high-level of viraemia. Our results suggest that, in patients from our cohort, infection by DENV serotype 3 elicits an innate response characterised by higher levels of IFN- β in the DHF patients with primary infection, which could contribute to control infection evidenced by the low-level of viraemia in these patients. The present findings may contribute to shed light in the role of innate immune response in dengue pathogenesis. PMID:27223651

  11. A Protective Role for Dengue Virus-Specific CD8+ T Cells

    OpenAIRE

    Yauch, Lauren E.; Zellweger, Raphaël M.; Kotturi, Maya F.; Qutubuddin, Afrina; Sidney, John; Peters, Bjoern; Prestwood, Tyler R.; Sette, Alessandro; Shresta, Sujan

    2009-01-01

    Infection with one of the four serotypes of dengue virus (DENV1-4) can result in a range of clinical manifestations in humans, from dengue fever to the more serious dengue hemorrhagic fever/dengue shock syndrome. Although T cells have been implicated in the immunopathogenesis of secondary infections with heterologous DENV serotypes, the role of T cells in protection against DENV is unknown. In this study, we used a mouse-passaged DENV2 strain, S221, to investigate the role of CD8+ T cells in ...

  12. Unusual Presentation of Dengue Fever; A child with acute myocarditis

    Directory of Open Access Journals (Sweden)

    Moaz Aslam

    2016-02-01

    Full Text Available Dengue fever (DF is an acute febrile illness that follows a self-limiting course. However, some patients suffer from complications, including myocarditis, due to the involvement of other organs. A child presented at the Aga Khan University Hospital in Karachi, Pakistan, in June 2013 with a high-grade fever, malaise and epigastric pain radiating to the chest. Positive DF antigen and immunoglobulin M assays confirmed the diagnosis of DF. Persistent bradycardia with low blood pressure led to further cardiac investigations which showed a decreased ejection fraction and raised serum cardiac enzymes, indicating myocardial damage. With supportive care and use of inotropes, the spontaneous normalisation of cardiac enzyme levels and ejection fraction was observed. The child was discharged five days after admission. This case highlights the importance of identifying myocarditis in DF patients suffering from cardiac symptoms that are not explained by other potential aetiologies. Awareness, early suspicion and supportive care are essential to ensure favourable outcomes.

  13. Characterization of an efficient dengue virus replicon for development of assays of discovery of small molecules against dengue virus.

    Science.gov (United States)

    Yang, Chi-Chen; Tsai, Ming-Han; Hu, Han-Shu; Pu, Szu-Yuan; Wu, Ren-Huang; Wu, Szu-Huei; Lin, Hui-Mei; Song, Jen-Shin; Chao, Yu-Sheng; Yueh, Andrew

    2013-05-01

    Dengue virus (DENV) is a public health threat to approximately 40% of the global population. At present, neither licensed vaccines nor effective therapies exist, and the mechanism of viral RNA replication is not well understood. Here, we report the development of efficient Renilla luciferase reporter-based DENV replicons that contain the full-length capsid sequence for transient and stable DENV RNA replication. A comparison of the transient and stable expression of this RNA-launched replicon to replicons containing various deletions revealed dengue replicon containing entire mature capsid RNA element has higher replicon activity. An efficient DNA-launched DENV replicon, pCMV-DV2Rep, containing a full-length capsid sequence, was created and successfully applied to evaluate the potency of known DENV inhibitors. Stable cell lines harboring the DENV replicon were easily established by transfecting pCMV-DV2Rep into BHK21 cells. Steady and high replicon reporter signals were observed in the stable DENV replicon cells, even after 30 passages. The stable DENV replicon cells were successfully used to determine the potency of known DENV inhibitors. A high-throughput screening assay based on stable DENV replicon cells was evaluated and shown to have an excellent Z' factor of 0.74. Altogether, the development of our efficient DENV replicon system will facilitate the study of virus replication and the discovery of antiviral compounds.

  14. Proteomic analysis of an Aedes albopictus cell line infected with Dengue serotypes 1 and 3 viruses

    Directory of Open Access Journals (Sweden)

    Thomas Frédéric

    2011-07-01

    Full Text Available Abstract Background Proteomic analysis was performed to identify proteins regulated during infection by Dengue serotypes 1 and 3 in an Aedes albopictus cell line. The potential of these viruses to cause severe disease at primary infection is of interest although few studies have been performed with these two Dengue serotypes. Results The most relevant observation of our study is the significant overexpression of proteins involved in the cellular stress response and the glycolysis pathway after 48 hours of infection. Viral infection activates the translation of some host genes, which may result in stress due to responses involving unfolded proteins. Conclusions Therefore, the oxidation reduction and glycolytic mechanisms could participate in the antiviral response against Dengue virus. The results of our study should help to improve our knowledge of the virus-mosquito interaction at a cellular level with the aim of designing efficient strategies for the control of Dengue virus.

  15. Complement-mediated neutralization of dengue virus requires mannose-binding lectin

    DEFF Research Database (Denmark)

    Avirutnan, Panisadee; Hauhart, Richard E; Marovich, Mary A;

    2011-01-01

    -dependent activation of the complement cascade neutralized insect cell-derived West Nile virus (WNV) in cell culture and restricted pathogenesis in mice. Here, we investigated the antiviral activity of MBL in infection by dengue virus (DENV), a related flavivirus. Using a panel of naïve sera from mouse strains...... with lower levels. Our studies suggest that allelic variation of MBL in humans may impact complement-dependent control of DENV pathogenesis. IMPORTANCE Dengue virus (DENV) is a mosquito-transmitted virus that causes a spectrum of clinical disease in humans ranging from subclinical infection to dengue...... hemorrhagic fever and dengue shock syndrome. Four serotypes of DENV exist, and severe illness is usually associated with secondary infection by a different serotype. Here, we show that mannose-binding lectin (MBL), a pattern recognition molecule that initiates the lectin pathway of complement activation...

  16. New insights into the immunopathology and control of dengue virus infection.

    Science.gov (United States)

    Screaton, Gavin; Mongkolsapaya, Juthathip; Yacoub, Sophie; Roberts, Catherine

    2015-12-01

    Dengue virus poses a major threat to global public health: two-thirds of the world's population is now at risk from infection by this mosquito-borne virus. Dengue virus causes a range of diseases with a small proportion of infected patients developing severe plasma leakage that leads to dengue shock syndrome, organ impairment and bleeding. Infection with one of the four viral serotypes results in the development of homotypic immunity to that serotype. However, subsequent infection with a different serotype is associated with an increased risk of developing severe disease, which has led to the suggestion that severe disease is triggered by immunopathology. This Review outlines recent advances in the understanding of immunopathology, vaccine development and human monoclonal antibodies produced against dengue virus.

  17. Proteomic profile of human monocytic cells infected with dengue virus

    Institute of Scientific and Technical Information of China (English)

    Viviana Martnez-Betancur; Marlen Martnez-Gutierrez

    2016-01-01

    Objective: To identify the changes in the proteome of U937 cells infected with dengue virus (DENV). Methods: In this study, differentiated U937 cultures were infected with two DENV-2 strains, one of which was associated with dengue (DENV-2/NG) and the other one with severe dengue (DENV-2/16681), with the aim of determining the cellular proteomic profiles under different infection conditions. Cellular proteins were extracted and sepa-rated by two-dimensional electrophoresis, and those proteins with differential expression profiles were identified by mass spectrometry. The obtained results were correlated with cellular viability, the number of infectious viral particles, and the viral DNA/protein quantity. Results: In comparison with non-infected cultures, in the cells infected with the DENV-2/NG strain, nine proteins were expressed differentially (five were upregulated and four were downregulated); in those cultures infected with the DENV-2/16681 strain, six proteins were differentially expressed (two were downregulated and four were upregu-lated). The downregulated proteins included fatty acid-binding protein, heterogeneous nuclear ribonucleoprotein 1, protein disulfide isomerase, enolase 1, heat shock 70 kDa protein 9, phosphotyrosyl phosphatase, and annexin IV. The upregulated proteins included heat shock 90 kDa protein AA1, tubulin beta, enolase 1, pyruvate kinase, transaldolase and phospholipase C-alpha. Conclusions: Because the monocyte/macrophage lineage is critical for disease patho-genicity, additional studies on these proteins could provide a better understanding of the cellular response to DENV infection and could help identify new therapeutic targets against infection.

  18. Regulation of T lymphocyte apoptotic markers is associated to cell activation during the acute phase of dengue.

    Science.gov (United States)

    Torrentes-Carvalho, Amanda; Marinho, Cintia Ferreira; de Oliveira-Pinto, Luzia Maria; de Oliveira, Débora Batista; Damasco, Paulo Vieira; Cunha, Rivaldo Venâncio; de Souza, Luiz José; de Azeredo, Elzinandes Leal; Kubelka, Claire Fernandes

    2014-05-01

    Dengue fever, a public health problem in Brazil, may present severe clinical manifestations as result of an increased vascular permeability and coagulation disorders. T cell activation is a critical event for an effective immune response against infection, including the production of cytokines. We aim to reveal mechanisms that modulate the virus-cell interaction, with an emphasis on cell death. Apoptosis is involved in lymphocyte homeostasis, contributes to the clearance of virus-infected cells but also may play a role in the pathogenesis. Phosphatidylserine exposure on CD8T lymphocytes from dengue patients support early apoptotic processes and loss of genomic integrity, observed by DNA fragmentation in T lymphocytes and indicating late apoptosis. These T cells express activation and cytotoxic phenotypes as revealed by CD29 and CD107a upregulation. Higher frequencies of CD95 were detected in T lymphocytes mainly in those with the cytotoxic profile (CD107a+) and lower levels of anti-apoptotic molecule Bcl-2, suggesting that both CD4+ and CD8+ T cell subsets are more susceptible to apoptosis during acute dengue. The analysis of apoptosis-related protein expression profile showed that not only molecules with pro- but also those with anti-apoptotic functions are overexpressed, indicating that survival mechanisms could be possibly protecting cells against apoptosis caused by viral, immune, oxidative and/or genotoxic stresses. These observations led us to propose that in dengue patients there is an association between T cell susceptibility to apoptosis and the activation state. The mechanisms for understanding the immunopathogenesis during dengue infection are discussed.

  19. Limiting influenza virus, HIV and dengue virus infection by targeting viral proteostasis

    Science.gov (United States)

    Heaton, Nicholas S.; Moshkina, Natasha; Fenouil, Romain; Gardner, Thomas J.; Aguirre, Sebastian; Shah, Priya S.; Zhao, Nan; Manganaro, Lara; Hultquist, Judd; Noel, Justine; Sachs, David; Hamilton, Jennifer; Leon, Paul E.; Chawdury, Amit; Tripathy, Shashank; Melegari, Camilla; Campisi, Laura; Hai, Rong; Metreveli, Giorgi; Gamarnik, Andrea V.; García-Sastre, Adolfo; Greenbaum, Benjamin; Simon, Viviana; Fernandez-Sesma, Ana; Krogan, Nevan; Mulder, Lubbertus C.F.; van Bakel, Harm; Tortorella, Domenico; Taunton, Jack; Palese, Peter; Marazzi, Ivan

    2016-01-01

    Viruses are obligate parasites as they require the machinery of the host cell to replicate. Inhibition of host factors co-opted during active infection is a strategy to suppress viral replication and a potential pan antiviral therapy. To define the cellular proteins and processes required for a virus during infection is thus crucial to understanding the mechanisms of virally induced disease. In this report, we generated fully infectious tagged influenza viruses and used infection-based proteomics to identify pivotal arms of cellular signaling required for influenza virus growth and infectivity. Using mathematical modeling, genetic, and pharmacologic approaches, we revealed that modulation of Sec61-mediated cotranslational translocation selectively impaired glycoprotein proteostasis of influenza as well as HIV and dengue viruses, and led to inhibition of viral growth and infectivity. Thus, by studying virus-human protein-protein interactions in the context of active replication we have identified targetable host factors for broad-spectrum antiviral therapies. PMID:26789921

  20. Impacts of chronic hepatitis B virus co-infection on immune responses and clinical manifestations in acute infection of dengue virus type 1%合并慢性乙型肝炎病毒感染对登革病毒1型急性感染者免疫应答和临床的影响

    Institute of Scientific and Technical Information of China (English)

    唐漾波; 张复春; 曹孟丽; 姚细安; 唐小平

    2011-01-01

    目的 了解合并慢性HBV感染对急性登革病毒感染引起的免疫应答和临床的影响.方法 采用ELISA法同时检测了310例登革病毒1型感染患者血清中IFNα、IFNβ、IFNγ、IL-10和TNFα等细胞因子水平,其中8%(25/310)合并感染了HBV,对照组的血清标本取自41名健康者和47例慢性HBV感染患者.多组比较采用单因素方差分析,检测指标的相关性分析采用Spearman等级相关检验.结果 在急性登革病毒感染期间,IFNα分泌水平显著高于IFNβ,分别为(95.1±279.3) pg/mL和(2.8土16.2)pg/mL,但在合并HBV感染的患者中IFNα的分泌明显减少,为(86.5±358.1) pg/mL;分别在发热第2天、第3~4天和第6天,IFNα、IFNβ及IL-10的中位数达到峰值.在单纯登革病毒感染的患者中,IFNα水平与血小板计数和血清ALT水平呈负相关(分别为r=-0.2327,-0.2122,均P<0.01).结论 合并慢性HBV感染可以改变急性登革病毒感染引起的免疫反应;IFNα的分泌可能与出血倾向相关,但对肝脏的炎性损伤可能起保护作用.%Objective To investigate impacts of chronic hepatitis B virus (HBV) co-infection on immune responses and clinical manifestations in acute infection of dengue virus type 1.Methods The serum levels of interferon (IFN)a,IFNβ,IFNγ,interleukin (IL)-10 and tumor necrosis factor (TNF)α of 310 dengue serotype 1 (DENV1)-infected patients were assessed by enzyme linked immunosorbent assay (ELISA),among which 8% (25/310) were chronic HBV co-infection.Meanwhile,serum samples from 41 healthy adults and 47 chronic HBV infected subjects were recruited as controls.Comparisons among groups were done by one factor analysis of variance and correlation analysis of results was done by spearman rank correlation test.Results The serum level of IFN-α [(95.1 ± 279.3) pg/mL] was significantly higher than IFN-β[(2.8 ± 16.2) pg/mL] during acute dengue infection,while IFN-α level [(86.5±358.1) pg/mL] reduced in patients with HBV

  1. Frequency and clinical manifestations of dengue in urban medellin, Colombia.

    Science.gov (United States)

    Restrepo, Berta Nelly; Beatty, Mark E; Goez, Yenny; Ramirez, Ruth E; Letson, G William; Diaz, Francisco J; Piedrahita, Leidy Diana; Osorio, Jorge E

    2014-01-01

    A dengue fever surveillance study was conducted at three medical facilities located in the low-income district of San Javier in Medellin, Colombia. During March 2008 to 2009, 781 patients with fever regardless of chief complaint were recruited for acute dengue virus infection testing. Of the 781 tested, 73 (9.3%) were positive for dengue infection. Serotypes DENV-2 (77%) and -3 (23%) were detected by PCR. One patient met the diagnostic criteria for dengue hemorrhagic fever. Only 3 out of 73 (4.1%) febrile subjects testing positive for dengue infection were diagnosed with dengue fever by the treating physician. This study confirms dengue virus as an important cause of acute febrile illness in Medellin, Colombia, but it is difficult to diagnose without dengue diagnostic testing.

  2. Frequency and Clinical Manifestations of Dengue in Urban Medellin, Colombia

    Directory of Open Access Journals (Sweden)

    Berta Nelly Restrepo

    2014-01-01

    Full Text Available A dengue fever surveillance study was conducted at three medical facilities located in the low-income district of San Javier in Medellin, Colombia. During March 2008 to 2009, 781 patients with fever regardless of chief complaint were recruited for acute dengue virus infection testing. Of the 781 tested, 73 (9.3% were positive for dengue infection. Serotypes DENV-2 (77% and -3 (23% were detected by PCR. One patient met the diagnostic criteria for dengue hemorrhagic fever. Only 3 out of 73 (4.1% febrile subjects testing positive for dengue infection were diagnosed with dengue fever by the treating physician. This study confirms dengue virus as an important cause of acute febrile illness in Medellin, Colombia, but it is difficult to diagnose without dengue diagnostic testing.

  3. Three-dimensional reconstruction of mature dengue virus cultured in neutral medium

    Institute of Scientific and Technical Information of China (English)

    LI Kunpeng; LI Yinyin; LI Jing; WEI wei; FANG Meiyu; LIU Jianwei

    2005-01-01

    @@ Dengue virus (DEN), a single positively stranded RNA virus, is a family member of Flaviviridae; it uses the mosquito A(e)des aegypti as its principle vector to cause what is known as Dengue fever. Its genome is ~10.8-kb in size and has one open reading frame encoding three structural proteins: capsid (C), precursor of the membrane (prM) and envelope (E), as well as seven non-structural proteins from a single polypeptide.

  4. A DNA Microarray-Based Assay to Detect Dual Infection with Two Dengue Virus Serotypes

    OpenAIRE

    Alvaro Díaz-Badillo; María de Lourdes Muñoz; Gerardo Perez-Ramirez; Victor Altuzar; Juan Burgueño; Mendoza-Alvarez, Julio G.; Martínez-Muñoz, Jorge P.; Alejandro Cisneros; Joel Navarrete-Espinosa; Feliciano Sanchez-Sinencio

    2014-01-01

    Here; we have described and tested a microarray based-method for the screening of dengue virus (DENV) serotypes. This DNA microarray assay is specific and sensitive and can detect dual infections with two dengue virus serotypes and single-serotype infections. Other methodologies may underestimate samples containing more than one serotype. This technology can be used to discriminate between the four DENV serotypes. Single-stranded DNA targets were covalently attached to glass slides and hybrid...

  5. Dissecting the Cell Entry Pathway of Dengue Virus by Single-Particle Tracking in Living Cells

    NARCIS (Netherlands)

    van der Schaar, Hilde M.; Rust, Michael J.; Chen, Chen; van der Ende-Metselaar, Heidi; Wilschut, Jan; Zhuang, Xiaowei; Smit, Jolanda M.

    2008-01-01

    Dengue virus (DENV) is an enveloped RNA virus that causes the most common arthropod-borne infection worldwide. The mechanism by which DENV infects the host cell remains unclear. In this work, we used live-cell imaging and single-virus tracking to investigate the cell entry, endocytic trafficking, an

  6. Miocarditis fulminante en una infección por virus dengue 1 en neiva, huila colombia

    OpenAIRE

    Salgado, Doris Martha; Vega, Martha Rocío; Panqueva, César; Rodríguez, Jairo Antonio

    2010-01-01

    Se presenta el caso de un niño de cinco años previamente sano quien fallece como consecuencia de un cuadro clínico compatible con miocarditis de curso fulminante asociada a fiebre dengue hemorrágica. Se demostró la presencia de virus dengue 1 en el tejido hepático mediante RT-PCR, por lo que se convierte en el primer caso reportado de miocarditis fulminante durante el curso de la infección por virus dengue en Neiva, Colombia.

  7. Vaccination with dengue virus-like particles induces humoral and cellular immune responses in mice

    Directory of Open Access Journals (Sweden)

    Zhang Quanfu

    2011-06-01

    Full Text Available Abstract Background The incidence of dengue, an infectious disease caused by dengue virus (DENV, has dramatically increased around the world in recent decades and is becoming a severe public health threat. However, there is currently no specific treatment for dengue fever, and licensed vaccine against dengue is not available. Vaccination with virus-like particles (VLPs has shown considerable promise for many viral diseases, but the effect of DENV VLPs to induce specific immune responses has not been adequately investigated. Results By optimizing the expression plasmids, recombinant VLPs of four antigenically different DENV serotypes DENV1-4 were successfully produced in 293T cells. The vaccination effect of dengue VLPs in mice showed that monovalent VLPs of each serotype stimulated specific IgG responses and potent neutralizing antibodies against homotypic virus. Tetravalent VLPs efficiently enhanced specific IgG and neutralizing antibodies against all four serotypes of DENV. Moreover, vaccination with monovalent or tetravalent VLPs resulted in the induction of specific cytotoxic T cell responses. Conclusions Mammalian cell expressed dengue VLPs are capable to induce VLP-specific humoral and cellular immune responses in mice, and being a promising subunit vaccine candidate for prevention of dengue virus infection.

  8. Elevated Dengue Virus Nonstructural Protein 1 Serum Levels and Altered Toll-Like Receptor 4 Expression, Nitric Oxide, and Tumor Necrosis Factor Alpha Production in Dengue Hemorrhagic Fever Patients

    Directory of Open Access Journals (Sweden)

    Denise Maciel Carvalho

    2014-01-01

    Full Text Available Background. During dengue virus (DV infection, monocytes produce tumor necrosis factor alpha (TNF-α and nitric oxide (NO which might be critical to immunopathogenesis. Since intensity of DV replication may determine clinical outcomes, it is important to know the effects of viral nonstructural protein 1 (NS1 on innate immune parameters of infected patients. The present study investigates the relationships between dengue virus nonstructural protein 1 (NS1 serum levels and innate immune response (TLR4 expression and TNF-α/NO production of DV infected patients presenting different clinical outcomes. Methodology/Principal Findings. We evaluated NO, NS1 serum levels (ELISA, TNF-α production by peripheral blood mononuclear cells (PBMCs, and TLR4 expression on CD14+ cells from 37 dengue patients and 20 healthy controls. Early in infection, increased expression of TLR4 in monocytes of patients with dengue fever (DF was detected compared to patients with dengue hemorrhagic fever (DHF. Moreover, PBMCs of DHF patients showed higher NS1 and lower NO serum levels during the acute febrile phase and a reduced response to TLR4 stimulation by LPS (with a reduced TNF-α production when compared to DF patients. Conclusions/Significance. During DV infection in humans, some innate immune parameters change, depending on the NS1 serum levels, and phase and severity of the disease which may contribute to development of different clinical outcomes.

  9. Construction and identification of reverse genetics system of Dengue type 2 virus isolated in China

    Institute of Scientific and Technical Information of China (English)

    ZHU Wuyang; CHEN Shuiping; QIN Chenggeng; YU Man; JIANG Tao; DENG Yongqiang; QIN Ede

    2006-01-01

    To construct infectious full-length cDNA clone of dengue virus type 2 isolated in China (DEN2-43), according to the published nucleotide sequence of the virus strain, the approximately 11 kb full-length cDNAs of DEN2-43 were amplified by long RT-PCR and fusion PCR. Full-length cDNA clones were constructed by inserting the full-length cDNA into a low copy vector pWSK29, from which rescued virus D212 was acquired by transcription in vitro and electroporation. The full-length cDNA clone pD212 was infectious, and rescued virus acquired in C6/36 cells was indistinguishable from DEN2-43 virus in biological properties including suckling mice neurovirulence. The reverse genetics system helps elucidate the mechanism of pathogenesis of dengue virus and develop novel vaccine against dengue.

  10. Acute Systemic Infection with Dengue Virus Leads to Vascular Leakage and Death through Tumor Necrosis Factor-α and Tie2/Angiopoietin Signaling in Mice Lacking Type I and II Interferon Receptors.

    Science.gov (United States)

    Phanthanawiboon, Supranee; Limkittikul, Kriengsak; Sakai, Yusuke; Takakura, Nobuyuki; Saijo, Masayuki; Kurosu, Takeshi

    2016-01-01

    Severe dengue is caused by host responses to viral infection, but the pathogenesis remains unknown. This is, in part, due to the lack of suitable animal models. Here, we report a non-mouse-adapted low-passage DENV-3 clinical isolate, DV3P12/08, derived from recently infected patients. DV3P12/08 caused a lethal systemic infection in type I and II IFN receptor KO mice (IFN-α/β/γR KO mice), which have the C57/BL6 background. Infection with DV3P12/08 induced a cytokine storm, resulting in severe vascular leakage (mainly in the liver, kidney and intestine) and organ damage, leading to extensive hemorrhage and rapid death. DV3P12/08 infection triggered the release of large amounts of TNF-α, IL-6, and MCP-1. Treatment with a neutralizing anti-TNF-α antibody (Ab) extended survival and reduced liver damage without affecting virus production. Anti-IL-6 neutralizing Ab partly prolonged mouse survival. The anti-TNF-α Ab suppressed IL-6, MCP-1, and IFN-γ levels, suggesting that the severe response to infection was triggered by TNF-α. High levels of TNF-α mRNA were expressed in the liver and kidneys, but not in the small intestine, of infected mice. Conversely, high levels of IL-6 mRNA were expressed in the intestine. Importantly, treatment with Angiopoietin-1, which is known to stabilize blood vessels, prolonged the survival of DV3P12/08-infected mice. Taken together, the results suggest that an increased level of TNF-α together with concomitant upregulation of Tie2/Angiopoietin signaling have critical roles in severe dengue infection.

  11. Spatial and temporal clustering of dengue virus transmission in Thai villages.

    Directory of Open Access Journals (Sweden)

    Mammen P Mammen

    2008-11-01

    Full Text Available Transmission of dengue viruses (DENV, the leading cause of arboviral disease worldwide, is known to vary through time and space, likely owing to a combination of factors related to the human host, virus, mosquito vector, and environment. An improved understanding of variation in transmission patterns is fundamental to conducting surveillance and implementing disease prevention strategies. To test the hypothesis that DENV transmission is spatially and temporally focal, we compared geographic and temporal characteristics within Thai villages where DENV are and are not being actively transmitted.Cluster investigations were conducted within 100 m of homes where febrile index children with (positive clusters and without (negative clusters acute dengue lived during two seasons of peak DENV transmission. Data on human infection and mosquito infection/density were examined to precisely (1 define the spatial and temporal dimensions of DENV transmission, (2 correlate these factors with variation in DENV transmission, and (3 determine the burden of inapparent and symptomatic infections. Among 556 village children enrolled as neighbors of 12 dengue-positive and 22 dengue-negative index cases, all 27 DENV infections (4.9% of enrollees occurred in positive clusters (p < 0.01; attributable risk [AR] = 10.4 per 100; 95% confidence interval 1-19.8 per 100]. In positive clusters, 12.4% of enrollees became infected in a 15-d period and DENV infections were aggregated centrally near homes of index cases. As only 1 of 217 pairs of serologic specimens tested in positive clusters revealed a recent DENV infection that occurred prior to cluster initiation, we attribute the observed DENV transmission subsequent to cluster investigation to recent DENV transmission activity. Of the 1,022 female adult Ae. aegypti collected, all eight (0.8% dengue-infected mosquitoes came from houses in positive clusters; none from control clusters or schools. Distinguishing features between

  12. Inhibition of dengue virus entry and multiplication into monocytes using RNA interference.

    Directory of Open Access Journals (Sweden)

    Mohammed Abdelfatah Alhoot

    2011-11-01

    Full Text Available BACKGROUND: Dengue infection ranks as one of the most significant viral diseases of the globe. Currently, there is no specific vaccine or antiviral therapy for prevention or treatment. Monocytes/macrophages are the principal target cells for dengue virus and are responsible for disseminating the virus after its transmission. Dengue virus enters target cells via receptor-mediated endocytosis after the viral envelope protein E attaches to the cell surface receptor. This study aimed to investigate the effect of silencing the CD-14 associated molecule and clathrin-mediated endocytosis using siRNA on dengue virus entry into monocytes. METHODOLOGY/PRINCIPAL FINDINGS: Gene expression analysis showed a significant down-regulation of the target genes (82.7%, 84.9 and 76.3% for CD-14 associated molecule, CLTC and DNM2 respectively in transfected monocytes. The effect of silencing of target genes on dengue virus entry into monocytes was investigated by infecting silenced and non-silenced monocytes with DENV-2. Results showed a significant reduction of infected cells (85.2%, intracellular viral RNA load (73.0%, and extracellular viral RNA load (63.0% in silenced monocytes as compared to non-silenced monocytes. CONCLUSIONS/SIGNIFICANCE: Silencing the cell surface receptor and clathrin mediated endocytosis using RNA interference resulted in inhibition of the dengue virus entry and subsequently multiplication of the virus in the monocytes. This might serve as a novel promising therapeutic target to attenuate dengue infection and thus reduce transmission as well as progression to severe dengue hemorrhagic fever.

  13. Altered immune response of immature dendritic cells upon dengue virus infection in the presence of specific antibodies

    NARCIS (Netherlands)

    Torres, Silvia; Flipse, Jacky; Upasani, Vinit C; van der Ende-Metselaar, Heidi; Urcuqui-Inchima, Silvio; Smit, Jolanda M; Rodenhuis-Zybert, Izabela A

    2016-01-01

    Dengue virus (DENV) replication is known to prevent maturation of infected DCs thereby impeding the development of adequate immunity. During secondary DENV infection, dengue-specific antibodies can suppress DENV replication in immature DCs (immDCs), however how dengue-antibody complexes (DENV-IC) in

  14. Physicians, Primary Caregivers and Topical Repellent: All Under-Utilised Resources in Stopping Dengue Virus Transmission in Affected Households.

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    Nguyet Minh Nguyen

    2016-05-01

    Full Text Available Primary health care facilities frequently manage dengue cases on an ambulatory basis for the duration of the patient's illness. There is a great opportunity for specific messaging, aimed to reduce dengue virus (DENV transmission in and around the home, to be directly targeted toward this high-risk ambulatory patient group, as part of an integrated approach to dengue management. The extent however, to which physicians understand, and can themselves effectively communicate strategies to stop focal DENV transmission around an ambulatory dengue case is unknown; the matter of patient comprehension and recollection then ensues. In addition, the effectiveness of N,N-diethyl-3-methylbenzamide (DEET-based insect repellent in protecting dengue patients from Aedes aegypti mosquitoes' bites has not been investigated.A knowledge, attitude and practice (KAP survey, focusing on the mechanisms of DENV transmission and prevention, was performed using semi-structured questionnaires. This survey was targeted towards the patients and family members providing supportive care, and physicians routinely involved in dengue patient management in Southern Vietnam. An additional clinical observational study was conducted to measure the efficacy of a widely-used 13% DEET-based insect repellent to repel Ae. aegypti mosquitoes from the forearms of dengue cases and matched healthy controls.Among both the physician (n = 50 and patient (n = 49 groups there were several respondents lacking a coherent understanding of DENV transmission, leading to some inappropriate attitudes and inadequate acute preventive practices in the household. The application of insect repellent to protect patients and their relatives from mosquito bites was frequently recommended by majority of physicians (78% participating in the survey. Nevertheless, our tested topical application of 13% DEET conferred only ~1hr median protection time from Ae. aegypti landing. This is notably shorter than that

  15. Binding of dengue virus particles and dengue proteins onto solid surfaces.

    Science.gov (United States)

    Pereira, Edla M A; Dario, Aline F; França, Rafael F O; Fonseca, Benedito A L; Petri, Denise F S

    2010-09-01

    The interaction between dengue virus particles (DENV), sedimentation hemagglutinin particles (SHA), dengue virus envelope protein (Eprot), and solid surfaces was investigated by means of ellipsometry and atomic force microscopy (AFM). The surfaces chosen are bare Si/SiO2 wafers and Si/SiO2 wafers covered with concanavalin A (ConA), jacalin (Jac), polystyrene (PS), or poly(styrene sulfonate) (PSS) films. Adsorption experiments at pH 7.2 and pH 3 onto all surfaces revealed that (i) adsorption of DENV particles took place only onto ConA under pH 7.2, because of specific recognition between glycans on DENV surface and ConA binding site; (ii) DENV particles did not attach to any of the surfaces at pH 3, suggesting the presence of positive charges on DENV surface at this pH, which repel the positively charged lectin surfaces; (iii) SHA particles are positively charged at pH 7.2 and pH 3 because they adhered to negatively charged surfaces at pH 7.2 and repelled positively charged layers at pH 3; and (iv) SHA particles carry polar groups on the surface because they attached to silanol surfaces at pH 3 and avoided hydrophobic PS films at pH 3 and pH 7.2. The adsorption behavior of Eprot at pH 7.2 revealed affinity for ConA>Jac>PSS>PS≈bare Si/SiO2 layers. These findings indicate that selectivity of the Eprot adsorption is higher when it is part of virus structure than when it is free in solution. The correlation between surface energy values determined by means of contact angle measurements and DENV, SHA, or Eprot adsorption behavior was used to understand the intermolecular forces at the interfaces. A direct correlation was not found because the contributions from surface energy were probably surpassed by specific contributions.

  16. The pathology of severe dengue in multiple organs of human fatal cases: histopathology, ultrastructure and virus replication.

    Science.gov (United States)

    Póvoa, Tiago F; Alves, Ada M B; Oliveira, Carlos A B; Nuovo, Gerard J; Chagas, Vera L A; Paes, Marciano V

    2014-01-01

    Dengue is a public health problem, with several gaps in understanding its pathogenesis. Studies based on human fatal cases are extremely important and may clarify some of these gaps. In this work, we analyzed lesions in different organs of four dengue fatal cases, occurred in Brazil. Tissues were prepared for visualization in optical and electron microscopy, with damages quantification. As expected, we observed in all studied organ lesions characteristic of severe dengue, such as hemorrhage and edema, although other injuries were also detected. Cases presented necrotic areas in the liver and diffuse macro and microsteatosis, which were more accentuated in case 1, who also had obesity. The lung was the most affected organ, with hyaline membrane formation associated with mononuclear infiltrates in patients with pre-existing diseases such as diabetes and obesity (cases 1 and 2, respectively). These cases had also extensive acute tubular necrosis in the kidney. Infection induced destruction of cardiac fibers in most cases, with absence of nucleus and loss of striations, suggesting myocarditis. Spleens revealed significant destruction of the germinal centers and atrophy of lymphoid follicles, which may be associated to decrease of T cell number. Circulatory disturbs were reinforced by the presence of megakaryocytes in alveolar spaces, thrombus formation in glomerular capillaries and loss of endothelium in several tissues. Besides histopathological and ultrastructural observations, virus replication were investigated by detection of dengue antigens, especially the non-structural 3 protein (NS3), and confirmed by the presence of virus RNA negative strand (in situ hybridization), with second staining for identification of some cells. Results showed that dengue had broader tropism comparing to what was described before in literature, replicating in hepatocytes, type II pneumocytes and cardiac fibers, as well as in resident and circulating monocytes/macrophages and

  17. The Pathology of Severe Dengue in Multiple Organs of Human Fatal Cases: Histopathology, Ultrastructure and Virus Replication

    Science.gov (United States)

    Póvoa, Tiago F.; Alves, Ada M. B.; Oliveira, Carlos A. B.; Nuovo, Gerard J.; Chagas, Vera L. A.; Paes, Marciano V.

    2014-01-01

    Dengue is a public health problem, with several gaps in understanding its pathogenesis. Studies based on human fatal cases are extremely important and may clarify some of these gaps. In this work, we analyzed lesions in different organs of four dengue fatal cases, occurred in Brazil. Tissues were prepared for visualization in optical and electron microscopy, with damages quantification. As expected, we observed in all studied organ lesions characteristic of severe dengue, such as hemorrhage and edema, although other injuries were also detected. Cases presented necrotic areas in the liver and diffuse macro and microsteatosis, which were more accentuated in case 1, who also had obesity. The lung was the most affected organ, with hyaline membrane formation associated with mononuclear infiltrates in patients with pre-existing diseases such as diabetes and obesity (cases 1 and 2, respectively). These cases had also extensive acute tubular necrosis in the kidney. Infection induced destruction of cardiac fibers in most cases, with absence of nucleus and loss of striations, suggesting myocarditis. Spleens revealed significant destruction of the germinal centers and atrophy of lymphoid follicles, which may be associated to decrease of T cell number. Circulatory disturbs were reinforced by the presence of megakaryocytes in alveolar spaces, thrombus formation in glomerular capillaries and loss of endothelium in several tissues. Besides histopathological and ultrastructural observations, virus replication were investigated by detection of dengue antigens, especially the non-structural 3 protein (NS3), and confirmed by the presence of virus RNA negative strand (in situ hybridization), with second staining for identification of some cells. Results showed that dengue had broader tropism comparing to what was described before in literature, replicating in hepatocytes, type II pneumocytes and cardiac fibers, as well as in resident and circulating monocytes/macrophages and

  18. The first case of laboratory-confirmed dengue virus infection in Mimika, Papua province, Indonesia

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    Agustiningsih Agustiningsih

    2016-07-01

    Full Text Available Abstrak Latar belakang: Dengue merupakan penyakit bersumber vektor yang berkontribusi cukup besar dalam menyebabkan masalah kesehatan baik di negara tropis maupun subtropis. Hingga saat ini virus dengue telah menyebar ke seluruh provinsi di Indonesia sejak pertama kali ditemukan di Surabaya pada tahun 1968. Kabupaten Mimika di propinsi Papua, Indonesia, merupakan daerah non-endemis dengue dan tidak pernah melaporkan munculnya kasus dengue. Walau begitu, pada tahun 2012 ditemukan 13 kasus tersangka dengue yang dirawat di Rumah Sakit Umum di Mimika. Studi ini bertujuan memberi gambaran karakteristik genetik virus dengue dari kasus terkonfirmasi (laboratory-confirmed pertama di kabupaten Mimika, propinsi Papua, Indonesia. Metode: Isolasi virus pada sel nyamuk C6/36, RT-PCR dan penentuan serotipe dilakukan untuk mengkonfirmasi adanya virus dengue (DENV di dalam serum pasien tersangka dengue dari kabupaten Mimika, propinsi Papua, Indonesia. Sekuensing dan analisis pohon filogenetik terhadap complete-coding sequence (CDS gen E dilakukan terhadap sampel yang telah positif DENV untuk penentuan genotipe virus. Hasil: Sebanyak 4 kasus tersangka dengue terkonfirmasi positif DENV berdasarkan pemeriksaan RT-PCR, sedangkan 2 sampel berhasil dilakukan kultur pada sel C6/36. Hasil penentuan serotipe menunjukkan bahwa virus DENV dari kabupaten Mimika, propinsi Papua, Indonesia, termasuk ke dalam serotipe DENV 3.  Analisis CDS gen E menunjukkan DENV 3 termasuk ke dalam genotipe I. Kesimpulan: Studi ini melaporkan kasus pertama dengue yang terkonfirmasi secara laboratorium dari kabupaten Mimika, propinsi Papua, Indonesia, yang merupakan daerah non-endemis dengue. Kata Kunci: dengue, penentuan serotipe, penentuan genotipe, kabupaten Mimika Abstract Background: Dengue is the most important vector-borne disease that poses serious health problem both in tropical and subtropical countries. Since the first outbreak in Surabaya in 1968, dengue infection has spread in

  19. Attenuation and immunogenicity of recombinant yellow fever 17D-dengue type 2 virus for rhesus monkeys

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    Galler R.

    2005-01-01

    Full Text Available A chimeric yellow fever (YF-dengue serotype 2 (dengue 2 virus was constructed by replacing the premembrane and envelope genes of the YF 17D virus with those from dengue 2 virus strains of Southeast Asian genotype. The virus grew to high titers in Vero cells and, after passage 2, was used for immunogenicity and attenuation studies in rhesus monkeys. Subcutaneous immunization of naive rhesus monkeys with the 17D-D2 chimeric virus induced a neutralizing antibody response associated with the protection of 6 of 7 monkeys against viremia by wild-type dengue 2 virus. Neutralizing antibody titers to dengue 2 were significantly lower in YF-immune animals than in YF-naive monkeys and protection against challenge with wild-type dengue 2 virus was observed in only 2 of 11 YF-immune monkeys. An anamnestic response to dengue 2, indicated by a sharp increase of neutralizing antibody titers, was observed in the majority of the monkeys after challenge with wild-type virus. Virus attenuation was demonstrated using the standard monkey neurovirulence test. The 17D-D2 chimera caused significantly fewer histological lesions than the YF 17DD virus. The attenuated phenotype could also be inferred from the limited viremias compared to the YF 17DD vaccine. Overall, these results provide further support for the use of chimeric viruses for the development of a new live tetravalent dengue vaccine.

  20. High Anti-Dengue Virus Activity of the OAS Gene Family Is Associated With Increased Severity of Dengue.

    Science.gov (United States)

    Simon-Loriere, Etienne; Lin, Ren-Jye; Kalayanarooj, Sita Mint; Chuansumrit, Ampaiwan; Casademont, Isabelle; Lin, Shyr-Yi; Yu, Han-Pang; Lert-Itthiporn, Worachart; Chaiyaratana, Wathanee; Tangthawornchaikul, Nattaya; Tangnararatchakit, Kanchana; Vasanawathana, Sirijitt; Chang, Bi-Lan; Suriyaphol, Prapat; Yoksan, Sutee; Malasit, Prida; Despres, Philipe; Paul, Richard; Lin, Yi-Ling; Sakuntabhai, Anavaj

    2015-12-15

    Dengue is a mosquito-borne viral disease that afflicts millions of individuals worldwide every year. Infection by any of the 4 dengue virus (DENV) serotypes can result in a spectrum of disease severity. We investigated the impact of variants of interferon-regulated innate immunity genes with a potent antiviral effect on the outcome of DENV infection. We compared the effect of OAS gene family variants on 2 DENV serotypes in cell culture. While both OAS1-p42 and p46 showed antiviral activity against DENV-2, only OAS1-p42 presented anti-DENV-1 activity. Conversely, whereas both OAS3_S381 and R381 variants were able to block DENV-1 infection, the anti-DENV-2 activity observed for OAS3_S381 was largely lost for the R381 variant. By means of an allelic association study of a cohort of 740 patients with dengue, we found a protective effect of OAS3_R381 against shock (odds ratio [OR], 0.37; P dengue has long been associated with a cytokine storm of unclear origin. This work identifies an early innate immunity process that could lead to the immune overreaction observed in severe dengue and could be triggered by a specific host genotype-pathogen genotype interaction.

  1. MIOCARDITIS FULMINANTE EN UNA INFECCIÓN POR VIRUS DENGUE 1 EN NEIVA, HUILA COLOMBIA Fatal myocarditis during a viral dengue 1 infection in Neiva, Huila Colombia

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    Doris Martha Salgado

    2008-06-01

    Full Text Available Se presenta el caso de un niño de cinco años previamente sano quien fallece como consecuencia de un cuadro clínico compatible con miocarditis de curso fulminante asociada a fiebre dengue hemorrágica. Se demostró la presencia de virus dengue 1 en el tejido hepático mediante RT-PCR, por lo que se convierte en el primer caso reportado de miocarditis fulminante durante el curso de la infección por virus dengue en Neiva, Colombia.A five year old boy previously healthy dies as a consequence of a dengue hemorrhagic fever-associated fulminant myocarditis. DEN 1 was showed in the liver tissue by RT-PCR. To our knowledge this is the first case of fulminant myocarditis during the course of dengue virus infection in Neiva, Colombia.

  2. High rate of unrecognized dengue virus infection in parts of the rainforest region of Nigeria.

    Science.gov (United States)

    Onoja, A B; Adeniji, J A; Olaleye, O D

    2016-08-01

    Outbreaks and sporadic dengue virus infections continue to occur in Africa. Several reports of dengue among travellers returning from some African countries to Europe and North America have raised concerns about the epidemiological situation in Africa. We investigated recent dengue infections in febrile patients during the rainy season in various urban centres in the rainforest region of Nigeria, West Africa. This cross-sectional study was conducted for 8 months in 2014 with study participants from Adeoyo Hospital Yemetu - Ibadan, Nigeria. Plasma were collected from 274 febrile patients residing in 11 Local Government Areas of Oyo State. IgM antibodies were determined using semi-quantitative sandwich ELISA. Data was analyzed using Chi - Square and Fisher's exact test with SPSS 16.0. An overall prevalence of 23.4% dengue virus infection was found among study participants. Highest monthly prevalence of 40% was in April and August. The monthly distribution pattern of dengue virus infection indicates efficient virus transmission. Routine diagnosis will enhance dengue virus surveillance and improve patient care in West Africa.

  3. Glycosylation of dengue virus glycoproteins and their interactions with carbohydrate receptors: possible targets for antiviral therapy.

    Science.gov (United States)

    Idris, Fakhriedzwan; Muharram, Siti Hanna; Diah, Suwarni

    2016-07-01

    Dengue virus, an RNA virus belonging to the genus Flavivirus, affects 50 million individuals annually, and approximately 500,000-1,000,000 of these infections lead to dengue hemorrhagic fever or dengue shock syndrome. With no licensed vaccine or specific antiviral treatments available to prevent dengue infection, dengue is considered a major public health problem in subtropical and tropical regions. The virus, like other enveloped viruses, uses the host's cellular enzymes to synthesize its structural (C, E, and prM/M) and nonstructural proteins (NS1-5) and, subsequently, to glycosylate these proteins to produce complete and functional glycoproteins. The structural glycoproteins, specifically the E protein, are known to interact with the host's carbohydrate receptors through the viral proteins' N-glycosylation sites and thus mediate the viral invasion of cells. This review focuses on the involvement of dengue glycoproteins in the course of infection and the virus' exploitation of the host's glycans, especially the interactions between host receptors and carbohydrate moieties. We also discuss the recent developments in antiviral therapies that target these processes and interactions, focusing specifically on the use of carbohydrate-binding agents derived from plants, commonly known as lectins, to inhibit the progression of infection.

  4. Immature dengue virus : functional properties and potential contribution to disease

    NARCIS (Netherlands)

    Da Silva-Voorham, Júlia Maria

    2013-01-01

    Beter inzicht in mechanismen achter infectieziekte dengue Dengue (‘knokkelkoorts’) is een veelvoorkomende, tropische infectieziekte die wordt overgebracht door muggen. Naar schatting raken jaarlijks zo’n vijftig tot honderd miljoen mensen besmet. Meestal gaat dengue vanzelf over, maar in zo’n 500.00

  5. Lymphocyte activation and hepatic cellular infiltration in immunocompetent mice infected by dengue virus.

    Science.gov (United States)

    Chen, Hsuen-Chin; Lai, Show-Yun; Sung, Jui-Min; Lee, Shu-Hwae; Lin, Yu-Chin; Wang, Wei-Kung; Chen, Yee-Chun; Kao, Chuan-Liang; King, Chwan-Chuen; Wu-Hsieh, Betty A

    2004-07-01

    Activation and expansion of dengue virus-specific T cells and abnormal liver functions in dengue patients have been documented. However, it remains to be determined whether T cells are involved in the pathogenic mechanism of dengue virus infection. In this study, immunocompetent C57BL/6 mice were employed to study dengue virus-induced T cell activation. Mice were inoculated with 10(8) PFU dengue virus serotype 2 strain 16681 by the intravenous route. Dengue viral core RNA was detected by RT-PCR in mouse serum, liver, spleen, and brain at different time points after infection. Splenic T cells were activated as evidenced by their expression of CD69 and O-glycosylated CD43 at as early as day 3 after infection. Splenic T cell expression of O-glycosylated CD43 and IFN-gamma production coordinately peaked at day 5. Coincided with the peak of splenic T cell activation was hepatic lymphocyte infiltration and elevation of liver enzymes. Flow cytometric analysis revealed the infiltrating CD8(+) T cell to CD4(+) T cell ratio was 5/3. After a second inoculation of dengue virus, hepatic T cell infiltration and liver enzyme levels increased sharply. The infiltrating hepatic CD8(+) T cell to CD4(+) T cell ratio increased to 5.8/1. A strong correlation was found between T cell activation and hepatic cellular infiltration in immunocompetent mice infected with dengue virus. The kinetics of liver enzyme elevation also correlated with that of T cell activation. These data suggest a relationship between T cell infiltration and elevation of liver enzymes.

  6. Clinical and histopathological features of fatal cases with dengue and chikungunya virus co-infection in Colombia, 2014 to 2015.

    Science.gov (United States)

    Mercado, Marcela; Acosta-Reyes, Jorge; Parra, Edgar; Pardo, Lissethe; Rico, Angélica; Campo, Alfonso; Navarro, Edgar; Viasus, Diego

    2016-06-02

    We report clinical features and histopathological findings in fatal cases with dengue (DENV) and chikungunya (CHIKV) co-infection identified at the Colombian National Institute of Health between September 2014 and October 2015. Seven such cases were documented. Dengue serotype 2 virus was identified in six cases. All patients were adults and comorbidities were present in four. Fever, arthralgia or myalgia was present in all cases. The frequency of rash, haemorrhage, oedema, and gastrointestinal symptoms was variable. Laboratory findings such as thrombocytopenia, renal failure, and leukocyte count were also inconsistent between cases. Post-mortem tissue examination documented focal hepatocellular coagulative necrosis in three cases, incipient acute pericarditis in one and tubulointerstitial nephritis in one. This study provides evidence of mortality in patients with DENV and CHIKV co-infection. Fatal cases were characterised by variable clinical and laboratory features. Evaluation of histopathology of autopsy tissues provided evidence of the pathological consequences of the disease.

  7. A Rapid and Improved Method to Generate Recombinant Dengue Virus Vaccine Candidates.

    Science.gov (United States)

    Govindarajan, Dhanasekaran; Guan, Liming; Meschino, Steven; Fridman, Arthur; Bagchi, Ansu; Pak, Irene; ter Meulen, Jan; Casimiro, Danilo R; Bett, Andrew J

    2016-01-01

    Dengue is one of the most important mosquito-borne infections accounting for severe morbidity and mortality worldwide. Recently, the tetravalent chimeric live attenuated Dengue vaccine Dengvaxia® was approved for use in several dengue endemic countries. In general, live attenuated vaccines (LAV) are very efficacious and offer long-lasting immunity against virus-induced disease. Rationally designed LAVs can be generated through reverse genetics technology, a method of generating infectious recombinant viruses from full length cDNA contained in bacterial plasmids. In vitro transcribed (IVT) viral RNA from these infectious clones is transfected into susceptible cells to generate recombinant virus. However, the generation of full-length dengue virus cDNA clones can be difficult due to the genetic instability of viral sequences in bacterial plasmids. To circumvent the need for a single plasmid containing a full length cDNA, in vitro ligation of two or three cDNA fragments contained in separate plasmids can be used to generate a full-length dengue viral cDNA template. However, in vitro ligation of multiple fragments often yields low quality template for IVT reactions, resulting in inconsistent low yield RNA. These technical difficulties make recombinant virus recovery less efficient. In this study, we describe a simple, rapid and efficient method of using LONG-PCR to recover recombinant chimeric Yellow fever dengue (CYD) viruses as potential dengue vaccine candidates. Using this method, we were able to efficiently generate several viable recombinant viruses without introducing any artificial mutations into the viral genomes. We believe that the techniques reported here will enable rapid and efficient recovery of recombinant flaviviruses for evaluation as vaccine candidates and, be applicable to the recovery of other RNA viruses.

  8. Structure and Function of the Non-Structural Protein of Dengue Virus and its Applications in Antiviral Therapy.

    Science.gov (United States)

    Xie, Qian; Zhang, Bao; Yu, JianHai; Wu, Qinghua; Yang, Fangji; Cao, Hong; Zhao, Wei

    2017-01-01

    Dengue fever, a type of global and tropical infectious disease, and its prevention has become a challenging issue worldwide. Antibody-dependent enhancement effects and the virus pathogenic mechanism have not yet been fully elucidated, hindering the development of dengue fever prevention and suitable drug treatment. There is currently no specific prevention and therapy in clinical trials, however, in recent years, studies have focused on the pathogenesis and treatment of dengue. Research focusing on dengue virus nonstructural protein in special drugs for the prevention and control of dengue fever is a new progress leading to improved understanding regarding the prevention and control of dengue fever and suitable drugs for the treatment. The main challenges regarding the structure of dengue virus nonstructural protein and the drugs for antiviral therapy are summarized in this paper.

  9. Modelling Virus and Antibody Dynamics during Dengue Virus Infection Suggests a Role for Antibody in Virus Clearance.

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    Hannah E Clapham

    2016-05-01

    Full Text Available Dengue is an infection of increasing global importance, yet uncertainty remains regarding critical aspects of its virology, immunology and epidemiology. One unanswered question is how infection is controlled and cleared during a dengue infection. Antibody is thought to play a role, but little past work has examined the kinetics of both virus and antibody during natural infections. We present data on multiple virus and antibody titres measurements recorded sequentially during infection from 53 Vietnamese dengue patients. We fit mechanistic mathematical models of the dynamics of viral replication and the host immune response to these data. These models fit the data well. The model with antibody removing virus fits the data best, but with a role suggested for ADCC or other infected cell clearance mechanisms. Our analysis therefore shows that the observed viral and antibody kinetics are consistent with antibody playing a key role in controlling viral replication. This work gives quantitative insight into the relationship between antibody levels and the efficiency of viral clearance. It will inform the future development of mechanistic models of how vaccines and antivirals might modify the course of natural dengue infection.

  10. Morphological studies in a model for dengue-2 virus infection in mice

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    Ortrud Monika Barth

    2006-12-01

    Full Text Available One of the main difficulties in studying dengue virus infection in humans and in developing a vaccine is the absence of a suitable animal model which develops the full spectrum of dengue fever, dengue haemorrhagic fever, and dengue shock syndrome. It is our proposal to present morphological aspects of an animal model which shows many similarities with the dengue infection in humans. BALB/c mice were intraperitoneally infected with non-neuroadapted dengue virus serotype 2 (DENV-2. Histopathological and morphometrical analyses of liver tissue revealed focal alterations along the infection, reaching wide-ranging portal and centrolobular veins congestion and sinusoidal cell death. Additional ultrastructural observations demonstrated multifocal endothelial injury, platelet recruitment, and alterated hepatocytes. Dengue virus antigen was detected in hepatocytes and in the capillar endothelium of the central lobular vein area. Liver function tests showed high levels of aspartate transaminase and alanine transaminase enzyme activity. Lung tissue showed interstitial pneumonia and mononuclear cells, interseptal oedema, hyperplasia, and hypertrophy of the bronchiolar epithelial cells. DENV-2 led to a transient inflammatory process, but caused focal alterations of the blood-exchange barrier. Viremia was observed from 2nd to 11th day p.i. by isolation of DENV-2 in C6/36 mosquito cell line inoculated with the supernatant of macerated liver, lung, kidney, and cerebellum tissues of the infected mice.

  11. Wolbachia-mediated resistance to dengue virus infection and death at the cellular level.

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    Francesca D Frentiu

    Full Text Available BACKGROUND: Dengue is currently the most important arthropod-borne viral disease of humans. Recent work has shown dengue virus displays limited replication in its primary vector, the mosquito Aedes aegypti, when the insect harbors the endosymbiotic bacterium Wolbachia pipientis. Wolbachia-mediated inhibition of virus replication may lead to novel methods of arboviral control, yet the functional and cellular mechanisms that underpin it are unknown. METHODOLOGY/PRINCIPAL FINDINGS: Using paired Wolbachia-infected and uninfected Aedes-derived cell lines and dengue virus, we confirm the phenomenon of viral inhibition at the cellular level. Although Wolbachia imposes a fitness cost to cells via reduced proliferation, it also provides a significant degree of protection from virus-induced mortality. The extent of viral inhibition is related to the density of Wolbachia per cell, with highly infected cell lines showing almost complete protection from dengue infection and dramatically reduced virus titers compared to lines not infected with the bacteria. CONCLUSIONS/SIGNIFICANCE: We have shown that cells infected with Wolbachia display inhibition of dengue virus replication, that the extent of inhibition is related to bacterial density and that Wolbachia infection, although costly, will provide a fitness benefit in some circumstances. Our results parallel findings in mosquitoes and flies, indicating that cell line models will provide useful and experimentally tractable models to study the mechanisms underlying Wolbachia-mediated protection from viruses.

  12. Research progress of dengue virus and dengue vaccines%登革病毒及登革热疫苗研究进展

    Institute of Scientific and Technical Information of China (English)

    李玉华

    2012-01-01

    Dengue virus can cause dengue fever,dengue hemorrhagic fever,and dengue shock syndrome.In recent years,dengue virus infection is posing a great threat to people's health.In order to research and develop safe and effective dengue vaccines,the updated biological characteristics and pathogenesis of dengue virus and research advance of dengue virus vaccines are summarized in this review.%登革病毒是引起人类疾病最重要的虫媒病毒,其感染可导致登革热、登革出血热、登革休克综合征,甚至危及患者生命.近年来,登革病毒的感染地域不断扩大,越来越多的国家和地区出现登革热流行或暴发,给公共卫生事业造成了很大的经济负担,对全球人类健康构成了极大威胁.为了加快安全有效的登革热疫苗的研发,此文就登革病毒结构、流行病学、致病机制、动物模型及疫苗的研究进展进行综述.

  13. Synchrony of sylvatic dengue isolations: a multi-host, multi-vector SIR model of dengue virus transmission in Senegal.

    Directory of Open Access Journals (Sweden)

    Benjamin M Althouse

    Full Text Available Isolations of sylvatic dengue-2 virus from mosquitoes, humans and non-human primates in Senegal show synchronized multi-annual dynamics over the past 50 years. Host demography has been shown to directly affect the period between epidemics in other pathogen systems, therefore, one might expect unsynchronized multi-annual cycles occurring in hosts with dramatically different birth rates and life spans. However, in Senegal, we observe a single synchronized eight-year cycle across all vector species, suggesting synchronized dynamics in all vertebrate hosts. In the current study, we aim to explore two specific hypotheses: 1 primates with different demographics will experience outbreaks of dengue at different periodicities when observed as isolated systems, and that coupling of these subsystems through mosquito biting will act to synchronize incidence; and 2 the eight-year periodicity of isolations observed across multiple primate species is the result of long-term cycling in population immunity in the host populations. To test these hypotheses, we develop a multi-host, multi-vector Susceptible, Infected, Removed (SIR model to explore the effects of coupling multiple host-vector systems of dengue virus transmission through cross-species biting rates. We find that under small amounts of coupling, incidence in the host species synchronize. Long-period multi-annual dynamics are observed only when prevalence in troughs reaches vanishingly small levels (< 10(-10, suggesting that these dynamics are inconsistent with sustained transmission in this setting, but are consistent with local dengue virus extinctions followed by reintroductions. Inclusion of a constant introduction of infectious individuals into the system causes the multi-annual periods to shrink, while the effects of coupling remain the same. Inclusion of a stochastic rate of introduction allows for multi-annual periods at a cost of reduced synchrony. Thus, we conclude that the eight-year period

  14. Acute Compressive Ulnar Neuropathy in a Patient of Dengue Fever: An Unusual Presentation

    Directory of Open Access Journals (Sweden)

    Anil K Mehtani

    2013-04-01

    Full Text Available Introduction: Dengue haemorrhagic fever is known for its haemorrhagic and neurologic complications. Neurologic complications are caused by three mechanism namely neurotropism, systemic complications causing encephalopathy and postinfectious immune-mediated mechanisms. However acute compressive neuropathy due to haemorrhage is not frequent and we could find no literature describing this Case Report: We report a case of acute compressive ulnar neuropathy due to peri neural hematoma, following an attempt at intravenous cannulation in the cubital fossa in a patient of dengue haemorrhagic fever with thrombocytopenia. Immediate fasciotomy and removal of haematoma was performed to relieve the symptoms. Conclusion: Compression neuropathies can be seen in dengue hemorrhagic fever and removal of compressing hematoma relieves symptoms. Keywords: Dengue haemmorrhagic fever; coagulopathy; peri neural haematoma.

  15. A prospective case-control study to investigate retinal microvascular changes in acute dengue infection.

    Science.gov (United States)

    Tan, Petrina; Lye, David C; Yeo, Tun Kuan; Cheung, Carol Y; Thein, Tun-Linn; Wong, Joshua G; Agrawal, Rupesh; Li, Ling-Jun; Wong, Tien-Yin; Gan, Victor C; Leo, Yee-Sin; Teoh, Stephen C

    2015-01-01

    Dengue infection can affect the microcirculation by direct viral infection or activation of inflammation. We aimed to determine whether measured retinal vascular parameters were associated with acute dengue infection. Patients with acute dengue were recruited from Communicable Diseases Center, Singapore and age-gender-ethnicity matched healthy controls were selected from a population-based study. Retinal photographs were taken on recruitment and convalescence. A spectrum of quantitative retinal microvascular parameters (retinal vascular caliber, fractal dimension, tortuosity and branching angle) was measured using a semi-automated computer-based program. (Singapore I Vessel Assessment, version 3.0). We included 62 dengue patients and 127 controls. Dengue cases were more likely to have wider retinal arteriolar and venular calibers (158.3 μm vs 144.3 μm, p dengue coincided with decrease in retinal vascular calibers and venular fractal dimension. Dengue patients have altered microvascular network in the retina; these changes may reflect pathophysiological processes in the immune system.

  16. Quantifying the spatial dimension of dengue virus epidemic spread within a tropical urban environment.

    Directory of Open Access Journals (Sweden)

    Gonzalo M Vazquez-Prokopec

    Full Text Available BACKGROUND: Dengue infection spread in naive populations occurs in an explosive and widespread fashion primarily due to the absence of population herd immunity, the population dynamics and dispersal of Ae. aegypti, and the movement of individuals within the urban space. Knowledge on the relative contribution of such factors to the spatial dimension of dengue virus spread has been limited. In the present study we analyzed the spatio-temporal pattern of a large dengue virus-2 (DENV-2 outbreak that affected the Australian city of Cairns (north Queensland in 2003, quantified the relationship between dengue transmission and distance to the epidemic's index case (IC, evaluated the effects of indoor residual spraying (IRS on the odds of dengue infection, and generated recommendations for city-wide dengue surveillance and control. METHODS AND FINDINGS: We retrospectively analyzed data from 383 DENV-2 confirmed cases and 1,163 IRS applications performed during the 25-week epidemic period. Spatial (local k-function, angular wavelets and space-time (Knox test analyses quantified the intensity and directionality of clustering of dengue cases, whereas a semi-parametric Bayesian space-time regression assessed the impact of IRS and spatial autocorrelation in the odds of weekly dengue infection. About 63% of the cases clustered up to 800 m around the IC's house. Most cases were distributed in the NW-SE axis as a consequence of the spatial arrangement of blocks within the city and, possibly, the prevailing winds. Space-time analysis showed that DENV-2 infection spread rapidly, generating 18 clusters (comprising 65% of all cases, and that these clusters varied in extent as a function of their distance to the IC's residence. IRS applications had a significant protective effect in the further occurrence of dengue cases, but only when they reached coverage of 60% or more of the neighboring premises of a house. CONCLUSION: By applying sound statistical analysis to a

  17. Pichia pastoris-Expressed Dengue 2 Envelope Forms Virus-Like Particles without Pre-Membrane Protein and Induces High Titer Neutralizing Antibodies

    OpenAIRE

    Shailendra Mani; Lav Tripathi; Rajendra Raut; Poornima Tyagi; Upasana Arora; Tarani Barman; Ruchi Sood; Alka Galav; Wahala Wahala; Aravinda de Silva; Sathyamangalam Swaminathan; Navin Khanna

    2013-01-01

    Dengue is a mosquito-borne viral disease with a global prevalence. It is caused by four closely-related dengue viruses (DENVs 1-4). A dengue vaccine that can protect against all four viruses is an unmet public health need. Live attenuated vaccine development efforts have encountered unexpected interactions between the vaccine viruses, raising safety concerns. This has emphasized the need to explore non-replicating dengue vaccine options. Virus-like particles (VLPs) which can elicit robust imm...

  18. Deeper understanding about the genetic structure of dengue virus using SVM

    Directory of Open Access Journals (Sweden)

    Choi Subin

    2016-01-01

    Full Text Available Dengue fever, mainly found in the tropical and subtropical regions, is carried by mosquitoes. With the help of greenhouse effect, places considered to be a Dengue safe-zone are becoming more and more dangerous. Dengue fever shows similar aspects to MERS, which caused heavy casualties in South Korea; Dengue virus does not have clear treatments nor vaccines like MERS. Development of Dengue vaccine is actively investigated lately. However, it is not easy to succeed; the fact that Dengue’s 4 serotypes have different properties and that repeated infections worsen the symptoms. This research aims to analyze the 4 serotypes (DENV1, DENV2, DENV3, DENV4 using SVM and ANN algorithms to investigate the constraints in the development of Dengue’s vaccines and treatments.

  19. Evolutionary Analysis of Dengue Serotype 2 Viruses Using Phylogenetic and Bayesian Methods from New Delhi, India.

    Directory of Open Access Journals (Sweden)

    Nazia Afreen

    2016-03-01

    Full Text Available Dengue fever is the most important arboviral disease in the tropical and sub-tropical countries of the world. Delhi, the metropolitan capital state of India, has reported many dengue outbreaks, with the last outbreak occurring in 2013. We have recently reported predominance of dengue virus serotype 2 during 2011-2014 in Delhi. In the present study, we report molecular characterization and evolutionary analysis of dengue serotype 2 viruses which were detected in 2011-2014 in Delhi. Envelope genes of 42 DENV-2 strains were sequenced in the study. All DENV-2 strains grouped within the Cosmopolitan genotype and further clustered into three lineages; Lineage I, II and III. Lineage III replaced lineage I during dengue fever outbreak of 2013. Further, a novel mutation Thr404Ile was detected in the stem region of the envelope protein of a single DENV-2 strain in 2014. Nucleotide substitution rate and time to the most recent common ancestor were determined by molecular clock analysis using Bayesian methods. A change in effective population size of Indian DENV-2 viruses was investigated through Bayesian skyline plot. The study will be a vital road map for investigation of epidemiology and evolutionary pattern of dengue viruses in India.

  20. Evolutionary Analysis of Dengue Serotype 2 Viruses Using Phylogenetic and Bayesian Methods from New Delhi, India.

    Science.gov (United States)

    Afreen, Nazia; Naqvi, Irshad H; Broor, Shobha; Ahmed, Anwar; Kazim, Syed Naqui; Dohare, Ravins; Kumar, Manoj; Parveen, Shama

    2016-03-01

    Dengue fever is the most important arboviral disease in the tropical and sub-tropical countries of the world. Delhi, the metropolitan capital state of India, has reported many dengue outbreaks, with the last outbreak occurring in 2013. We have recently reported predominance of dengue virus serotype 2 during 2011-2014 in Delhi. In the present study, we report molecular characterization and evolutionary analysis of dengue serotype 2 viruses which were detected in 2011-2014 in Delhi. Envelope genes of 42 DENV-2 strains were sequenced in the study. All DENV-2 strains grouped within the Cosmopolitan genotype and further clustered into three lineages; Lineage I, II and III. Lineage III replaced lineage I during dengue fever outbreak of 2013. Further, a novel mutation Thr404Ile was detected in the stem region of the envelope protein of a single DENV-2 strain in 2014. Nucleotide substitution rate and time to the most recent common ancestor were determined by molecular clock analysis using Bayesian methods. A change in effective population size of Indian DENV-2 viruses was investigated through Bayesian skyline plot. The study will be a vital road map for investigation of epidemiology and evolutionary pattern of dengue viruses in India.

  1. Identification of covalent active site inhibitors of dengue virus protease

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    Koh-Stenta X

    2015-12-01

    Full Text Available Xiaoying Koh-Stenta,1 Joma Joy,1 Si Fang Wang,1 Perlyn Zekui Kwek,1 John Liang Kuan Wee,1 Kah Fei Wan,2 Shovanlal Gayen,1 Angela Shuyi Chen,1 CongBao Kang,1 May Ann Lee,1 Anders Poulsen,1 Subhash G Vasudevan,3 Jeffrey Hill,1 Kassoum Nacro11Experimental Therapeutics Centre, Agency for Science, Technology and Research (A*STAR, Singapore; 2Novartis Institute for Tropical Diseases, Singapore; 3Program in Emerging Infectious Diseases, Duke-NUS Graduate Medical School, SingaporeAbstract: Dengue virus (DENV protease is an attractive target for drug development; however, no compounds have reached clinical development to date. In this study, we utilized a potent West Nile virus protease inhibitor of the pyrazole ester derivative class as a chemical starting point for DENV protease drug development. Compound potency and selectivity for DENV protease were improved through structure-guided small molecule optimization, and protease-inhibitor binding interactions were validated biophysically using nuclear magnetic resonance. Our work strongly suggests that this class of compounds inhibits flavivirus protease through targeted covalent modification of active site serine, contrary to an allosteric binding mechanism as previously described.Keywords: flavivirus protease, small molecule optimization, covalent inhibitor, active site binding, pyrazole ester derivatives

  2. Multiplex real-time RT-PCR for detecting chikungunya virus and dengue virus

    Institute of Scientific and Technical Information of China (English)

    Piyathida Pongsiri; Kesmanee Praianantathavorn; Apiradee Theamboonlers; Sunchai Payungporn; Yong Poovorawan

    2012-01-01

    ABSTRACT Objective:To develop diagnostic test for detection chikungunya virus (CHIKV and Dengue virus (DENV)infection.Methods:We have performed a rapid, accurate laboratory confirmative method to simultaneously detect, quantify and differentiateCHIKV and DENV infection by single-step multiplex real-timeRT-PCR.Results: The assay’s sensitivity was97.65%, specificity was 92.59% and accuracy was95.82% when compared to conventional RT-PCR. Additionally, there was no cross-reaction betweenCHIKV, DENV, Japanese encephalitis virus, hepatitis C, hepatitis A or hepatitis E virus.Conclusions:This rapid and reliable assay provides a means for simultaneous early diagnosis ofCHIKV andDENV in a single-step reaction.

  3. Evaluation of a pan-serotype point-of-care rapid diagnostic assay for accurate detection of acute dengue infection.

    Science.gov (United States)

    Vivek, Rosario; Ahamed, Syed Fazil; Kotabagi, Shalini; Chandele, Anmol; Khanna, Ira; Khanna, Navin; Nayak, Kaustuv; Dias, Mary; Kaja, Murali-Krishna; Shet, Anita

    2017-03-01

    The catastrophic rise in dengue infections in India and globally has created a need for an accurate, validated low-cost rapid diagnostic test (RDT) for dengue. We prospectively evaluated the diagnostic performance of NS1/IgM RDT (dengue day 1) using 211 samples from a pediatric dengue cohort representing all 4 serotypes in southern India. The dengue-positive panel consisted of 179 dengue real-time polymerase chain reaction (RT-PCR) positive samples from symptomatic children. The dengue-negative panel consisted of 32 samples from dengue-negative febrile children and asymptomatic individuals that were negative for dengue RT-PCR/NS1 enzyme-linked immunosorbent assay/IgM/IgG. NS1/IgM RDT sensitivity was 89.4% and specificity was 93.8%. The NS1/IgM RDT showed high sensitivity throughout the acute phase of illness, in primary and secondary infections, in different severity groups, and detected all 4 dengue serotypes, including coinfections. This NS1/IgM RDT is a useful point-of-care assay for rapid and reliable diagnosis of acute dengue and an excellent surveillance tool in our battle against dengue.

  4. Isolation, identification, and phylogenetic analysis of a dengue virus strain from Aedes albopictus collected in Mawei town in Guizhou Province, China

    Institute of Scientific and Technical Information of China (English)

    左丽; 舒莉萍

    2004-01-01

    @@ Dengue virus (DEN), a single-stranded RNA virus of the family Flaviviridae, is transmitted from one infected person or animal to another by the mosquitos Aedes albopictus and Aedes aegypti. There are four serotypes of the dengue virus (serotypes 1-4). The virus is responsible for dengue fever (DF), dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). In the recent years, the incidence rate of DF/DHF has been increasing around the world, particularly in tropical and subtropical zones. Dengue is the most significant arthropod-borne viral disease affecting public health.1

  5. [Co-infection by Chikungunya virus (CHIK-V) and dengue virus (DEN-V) during a recent outbreak in Cali, Colombia: Report of a fatal case].

    Science.gov (United States)

    Rosso, Fernando; Pacheco, Robinson; Rodríguez, Sarita; Bautista, Diego

    2016-08-01

    The recent outbreaks of Chikungunya (CHIK-V) virus in endemic areas of dengue (DEN-V) could increase the risk of co-infection. CHIK infection has been considered not severe and with very unusual mortality, however DEN is associated with severe manifestations and increased mortality. Little is known about coinfection. It is possible that co-infection could generate severe cases. We present a case report of co-infection DEN-V -3 and CHIK-V in an elderly patient who developed acute renal failure, dengue shock syndrome (DSS), progresses to multiple organ failure and died. With the recent emergence of CHIK-V in Colombia, the possibility of co-infection with DEN-V should be suspected, especially in severe cases.

  6. Dengue as a cause of acute undifferentiated fever in Vietnam

    NARCIS (Netherlands)

    Phuong, H.L.; de Vries, P.J.; Nga, T.T.T.; Giao, P.T.; Hung, L.Q.; Binh, T.Q.; Nam, N.V.; Nagelkerke, N.; Kager, P.A.

    2006-01-01

    Background: Dengue is a common cause of fever in the tropics but its contribution to the total burden of febrile illnesses that is presented to primary health facilities in endemic regions such as Vietnam, is largely unknown. We aimed to report the frequency of dengue as a cause of fever in Binh Thu

  7. Phylogenetic analysis of Dengue virus 1 isolated from South Minas Gerais, Brazil

    Science.gov (United States)

    Drumond, Betania Paiva; da Silva Fagundes, Luiz Gustavo; Rocha, Raissa Prado; Fumagalli, Marcilio Jorge; Araki, Carlos Shigueru; Colombo, Tatiana Elisa; Nogueira, Mauricio Lacerda; Castilho, Thiago Elias; da Silveira, Nelson José Freitas; Malaquias, Luiz Cosme Cotta; Coelho, Luiz Felipe Leomil

    2016-01-01

    Dengue is a major worldwide public health problem, especially in the tropical and subtropical regions of the world. Primary infection with a single Dengue virus serotype causes a mild, self-limiting febrile illness called dengue fever. However, a subset of patients who experience secondary infection with a different serotype can progress to a more severe form of the disease, called dengue hemorrhagic fever. The four Dengue virus serotypes (1–4) are antigenically and genetically distinct and each serotype is composed of multiple genotypes. In this study we isolated one Dengue virus 1 serotype, named BR/Alfenas/2012, from a patient with dengue hemorrhagic fever in Alfenas, South Minas Gerais, Brazil and molecular identification was performed based on the analysis of NS5 gene. Swiss mice were infected with this isolate to verify its potential to induce histopathological alterations characteristic of dengue. Liver histopathological analysis of infected animals showed the presence of inflammatory infiltrates, hepatic steatosis, as well as edema, hemorrhage and necrosis focal points. Phylogenetic and evolutionary analyses based on the envelope gene provided evidence that the isolate BR/Alfenas/2012 belongs to genotype V, lineage I and it is probably derived from isolates of Rio de Janeiro, Brazil. The isolate BR/Alfenas/2012 showed two unique amino acids substitutions (SER222THRE and PHE306SER) when compared to other Brazilian isolates from the same genotype/lineage. Molecular models were generated for the envelope protein indicating that the amino acid alteration PHE 306 SER could contribute to a different folding in this region located within the domain III. Further genetic and animal model studies using BR/Alfenas/2012 and other isolates belonging to the same lineage/genotype could help determine the relation of these genetic alterations and dengue hemorrhagic fever in a susceptible population. PMID:26887252

  8. Phylogenetic analysis of Dengue virus 1 isolated from South Minas Gerais, Brazil.

    Science.gov (United States)

    Drumond, Betania Paiva; Fagundes, Luiz Gustavo da Silva; Rocha, Raissa Prado; Fumagalli, Marcilio Jorge; Araki, Carlos Shigueru; Colombo, Tatiana Elisa; Nogueira, Mauricio Lacerda; Castilho, Thiago Elias; da Silveira, Nelson José Freitas; Malaquias, Luiz Cosme Cotta; Coelho, Luiz Felipe Leomil

    2016-01-01

    Dengue is a major worldwide public health problem, especially in the tropical and subtropical regions of the world. Primary infection with a single Dengue virus serotype causes a mild, self-limiting febrile illness called dengue fever. However, a subset of patients who experience secondary infection with a different serotype can progress to a more severe form of the disease, called dengue hemorrhagic fever. The four Dengue virus serotypes (1-4) are antigenically and genetically distinct and each serotype is composed of multiple genotypes. In this study we isolated one Dengue virus 1 serotype, named BR/Alfenas/2012, from a patient with dengue hemorrhagic fever in Alfenas, South Minas Gerais, Brazil and molecular identification was performed based on the analysis of NS5 gene. Swiss mice were infected with this isolate to verify its potential to induce histopathological alterations characteristic of dengue. Liver histopathological analysis of infected animals showed the presence of inflammatory infiltrates, hepatic steatosis, as well as edema, hemorrhage and necrosis focal points. Phylogenetic and evolutionary analyses based on the envelope gene provided evidence that the isolate BR/Alfenas/2012 belongs to genotype V, lineage I and it is probably derived from isolates of Rio de Janeiro, Brazil. The isolate BR/Alfenas/2012 showed two unique amino acids substitutions (SER222THRE and PHE306SER) when compared to other Brazilian isolates from the same genotype/lineage. Molecular models were generated for the envelope protein indicating that the amino acid alteration PHE 306 SER could contribute to a different folding in this region located within the domain III. Further genetic and animal model studies using BR/Alfenas/2012 and other isolates belonging to the same lineage/genotype could help determine the relation of these genetic alterations and dengue hemorrhagic fever in a susceptible population.

  9. Detection antigen virus den on monocyts by streptavidin biotin test as early diagnostic for dengue fever hemorrhagic

    Directory of Open Access Journals (Sweden)

    Y NINING SRI WURYANINGSIH

    2007-07-01

    Full Text Available Dengue virus infection is the main cause of morbidity and mortality in the tropical and sub-tropical countries of the world. Clinically it may manifest as asymtomastic,undifferentiated fever,dengue ever,dengue haemorrhagic fever and dengue shock syndrome cases. The mechanism underlying the disease with severe complication is not clear yet,however it has been previosus reported that primary and secondary infections of dengue virus play an important role in the patogenesis of this diseases. Early diagnosis of dengue virus infection has a great contribution for appropriate management of the disease, especialy for the prognosis of the patient. Laboratory investigations for such cases will be methods on serological investigation as well as virus isolation and identification.of dengue virus infection could be made by detection of specific virus ,viral antigen,genomic sequence and or detection of antibodies. These methods are sensitive and precise for detecting dengue virus infection,but there need special equipment,costly and detection of IgM and IgG often positive or negative false the dengue virus in the blood stream There for, this study was performed in order to develop a method to detect dengue virus antigen on the monocytes using Streptavidin biotin technique. The result of Streptavidin biotin study demonstrated that 32 sera from patient suspected with DHF 78,1% were positive DHF,and 21,9% were negative DHF. These results are consistent with the result from WHO criteria as standard .The Chi Square analysis showed that the presentage of sensitivity and specificity of Streptavidin biotin methode were 88% and 87,7% respectively. In conclusions, immunocytochemistry method using streptavidin biotin technique could be used as a method to detect antigen dengue virus on monocytes in the serum patient suspected with DHF. This technique has high sensitivity and specivicity and consistent with the clinical WHO criteria for DHF.

  10. Two Complex, Adenovirus-Based Vaccines That Together Induce Immune Responses to All Four Dengue Virus Serotypes▿

    OpenAIRE

    Holman, David H.; Wang, Danher; Raviprakash, Kanakatte; Raja, Nicholas U.; LUO, MIN; Zhang, Jianghui; Porter, Kevin R.; Dong, John Y.

    2006-01-01

    Dengue virus infections can cause hemorrhagic fever, shock, encephalitis, and even death. Worldwide, approximately 2.5 billion people live in dengue-infested regions with about 100 million new cases each year, although many of these infections are believed to be silent. There are four antigenically distinct serotypes of dengue virus; thus, immunity from one serotype will not cross-protect from infection with the other three. The difficulties that hamper vaccine development include requirement...

  11. Coinfection with influenza A(H1N1)pdm09 and dengue virus in fatal cases.

    Science.gov (United States)

    Perdigão, Anne Carolinne Bezerra; Ramalho, Izabel Letícia Cavalcante; Guedes, Maria Izabel Florindo; Braga, Deborah Nunes Melo; Cavalcanti, Luciano Pamplona Góes; Melo, Maria Elisabeth Lisboa de; Araújo, Rafael Montenegro de Carvalho; Lima, Elza Gadelha; Silva, Luciene Alexandre Bié da; Araújo, Lia de Carvalho; Araújo, Fernanda Montenegro de Carvalho

    2016-09-01

    We report on four patients with fatal influenza A(H1N1)pdm09 and dengue virus coinfections. Clinical, necropsy and histopathologic findings presented in all cases were characteristic of influenza-dengue coinfections, and all were laboratory-confirmed for both infections. The possibility of influenza and dengue coinfection should be considered in locations where these two viruses' epidemic periods coincide to avoid fatal outcomes. Dengue is a mosquito-borne viral infection caused by one of the four dengue viruses (DENV-1 to 4). Each of these viruses is capable of causing nonspecific febrile illnesses, classic dengue fever and dengue haemorrhagic fever (Gubler 1998). As a result, dengue is often difficult to diagnose clinically, especially because peak dengue season often coincides with that of other common febrile illnesses in tropical regions (Chacon et al. 2015). In April 2009, a new virus, influenza A/H1N1/pandemic (FluA/H1N1/09pdm), caused a severe outbreak in Mexico. The virus quickly spread throughout the world, and in June 2009, the World Health Organization declared a pandemic (WHO 2010). In Brazil, the first laboratory confirmed case of FluA/H1N1/09pdm was in July 2009 (Pires Neto et al. 2013). The state of Ceará, in Northeast Brazil, is a dengue endemic area. In this state, the virus influenza A(H1N1)pdm09 has circulated since 2009, and through the first half of 2012, 11 deaths caused by the virus were confirmed (Pires Neto et al. 2013). The influenza and dengue seasons in Ceará overlap, which led to diagnostic difficulties. We report four cases of laboratory-confirmed coinfection of deadly influenza A(H1N1)pdm09 with DENV, which occurred during the dengue and influenza season in 2012 and 2013 in Ceará.

  12. Aedes albopictus may not be vector of dengue virus in human epidemics in Brazil

    Directory of Open Access Journals (Sweden)

    Degallier Nicolas

    2003-01-01

    Full Text Available Over 60,500 dengue cases were reported in the state of Espírito Santo (ES, Brazil, between 1995 and 1998. The study's purpose was to identify whether Aedes albopictus was transmitting the dengue virus during an epidemic in the locality of Vila Bethânia (Viana County,Vitória, ES. From April 3 to 9, 1998, blood and serum samples were collected daily for virus isolation and serological testing. Four autochthonous cases were confirmed through DEN 1 virus isolation and two autochthonous cases through MAC ELISA testing. Of 37 Ae. aegypti and 200 Ae. albopictus adult mosquitoes collected and inoculated, DEN1 virus was isolated only from a pool of two Ae. aegypti female mosquitoes. The study results suggest that Ae. albopictus still cannot be considered an inter-human vector in dengue epidemics in Brazil.

  13. Brote epidémico de denguevirus 2, genotipo Jamaica, en Bolivia Epidemic outbreak of dengue virus 2/subgroup Jamaica in Bolivia

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    Alberto Gianella

    1998-11-01

    Full Text Available Objetivo. Confirmar la presencia de brote de dengue en la ciudad de Santa Cruz, Bolivia, así como identificar el denguevirus causal, estimar la tasa de ataque y determinar la proporción de infecciones sintomáticas. Material y métodos. En marzo de 1997 se realizó una encuesta seroepidemiológica con muestreo aleatorio en un distrito céntrico de la ciudad. Se obtuvo información sobre episodios de enfermedad aguda, antecedentes de cuadro febril reciente y muestras de sangre venosa. Se determinó la presencia de IgM antidengue con el método MAC ELISA y se procedió a la tipificación del virus con tecnología de reacción en cadena de la polimerasa. Resultados. Se detectaron anticuerpos IgM en 6.5% de los adultos (IC95% 3.4-9.6 y 5.1% de los niños (IC 95% 2.0-8.2. El virus circulante fue identificado como dengue serotipo 2, genotipo Jamaica. Menos de la mitad de los niños infectados tuvieron una infección sintomática, contra casi 90% de los adultos. Conclusiones. La tasa de ataque estimada es compatible con una epidemia de dengue en Santa Cruz. La introducción del serotipo 2 - Jamaica en el país aumenta el riesgo de dengue hemorrágico.Objective. To confirm an epidemic outbreak of Dengue virus in the city of Santa Cruz, Bolivia, and to determine the serotype of the virus, to estimate the rate of attack and the proportion of symptomatic infections. Material and methods. In March 1997, a seroepidemiological survey was conducted with random sampling in a central district of the city of Santa Cruz, Bolivia. Information on recent acute illness and febrile episodes was gathered, and venous blood samples were obtained. Levels of antidengue IgM were determined by MAC Elisa and the virus was tipified with RT-PCR. Results. IgM antibodies were detected in 6.5% of adults (CI 95% 3.4-9.6 and 5.1% of children (CI 95% 2.0-8.2. Circulating virus was identified as Dengue serotype 2, subgroup Jamaica. Less than half of the infected children experienced

  14. Optical diagnosis of dengue virus infected human blood using Mueller matrix polarimetry

    Science.gov (United States)

    Anwar, Shahzad; Firdous, Shamaraz

    2016-08-01

    Currently dengue fever diagnosis methods include capture ELISAs, immunofluorescence tests, and hemagglutination assays. In this study optical diagnosis of dengue virus infection in the whole blood is presented utilizing Mueller matrix polarimetry. Mueller matrices of about 50 dengue viral infected and 25 non-dengue healthy blood samples were recorded utilizing light source from 500 to 700 nm with scanning step of 10 nm. Polar decomposition of the Mueller matrices for all the blood samples was performed that yielded polarization properties including depolarization, diattenuation, degree of polarization, retardance and optical activity, out of which, depolarization index clusters up the diseased and healthy in to different separate groups. The average depolarized light in the case of dengue infection in the whole blood at 500 nm is 18%, whereas for the healthy blood samples it is 13.5%. This suggests that depolarization index of polarized light at the wavelengths of 500, 510, 520, 530 and 540 nm, we find that in case of depolarization index values are higher for dengue viral infection as compared to normal samples. This technique can effectively be used for the characterization of the dengue virus infected at an early stage of disease.

  15. Laboratory-Based Surveillance and Molecular Characterization of Dengue Viruses in Taiwan, 2014.

    Science.gov (United States)

    Chang, Shu-Fen; Yang, Cheng-Fen; Hsu, Tung-Chieh; Su, Chien-Ling; Lin, Chien-Chou; Shu, Pei-Yun

    2016-04-01

    We present the results of a laboratory-based surveillance of dengue in Taiwan in 2014. A total of 240 imported dengue cases were identified. The patients had arrived from 16 countries, and Malaysia, Indonesia, the Philippines, and China were the most frequent importing countries. Phylogenetic analyses showed that genotype I of dengue virus type 1 (DENV-1) and the cosmopolitan genotype of DENV-2 were the predominant DENV strains circulating in southeast Asia. The 2014 dengue epidemic was the largest ever to occur in Taiwan since World War II, and there were 15,492 laboratory-confirmed indigenous dengue cases. Phylogenetic analysis showed that the explosive dengue epidemic in southern Taiwan was caused by a DENV-1 strain of genotype I imported from Indonesia. There were several possible causes of this outbreak, including delayed notification of the outbreak, limited staff and resources for control measures, abnormal weather conditions, and a serious gas pipeline explosion in the dengue hot spot areas in Kaohsiung City. However, the results of this surveillance indicated that both active and passive surveillance systems should be strengthened so appropriate public health measures can be taken promptly to prevent large-scale dengue outbreaks.

  16. Virus de dengue en personas asintomáticas del poblado de Yariguá

    OpenAIRE

    Meidis del Rio Bolmey; Karell R. Vázquez Argote

    2014-01-01

    Se realizó un estudio observacional descriptivo de corte transversal, para determinar la seroprevalencia de anticuerpos Inmunoglobulinas M (IgM) Dengue en personas que tuvieron una infección asintomática por el virus del dengue, en la localidad de Yariguá en el municipio Las Tunas, Cuba, donde se presentó un brote en el período de diciembre 2006 a enero 2007. Se analizaron 156 muestras de personas asintomáticas. Se realizó interrogatorio a los pacientes y la detección de IgM Dengue, utilizand...

  17. Analysis of Dengue Virus Enhancing Epitopes Using Peptide Antigens Derived from the Envelope Glycoprotein Gene Sequence

    Science.gov (United States)

    1990-11-27

    WE. 1990. Development of dengue and Japanese encephalitis Vaccines . J Infect Dis 162:577-83. 2. Brandt WE, McCown JM, Gentry MK, and Russell PK. i982...7. 19. Roehrig JT, Johnson AJ, Hunt AR, Bolin RA, •d Chu MC. 1990. Antibodies to dengue 2 Jamaica E-glycopr tein synthetic peptides identify antigenic...AD________ AD-A230 976 ARMY PROJECT NO: 89PP9961 TITLE: ANALYSIS OF DENGUE VIRUS ENHANCING EPITOPES USING PEPTIDE ANTIGENS DERIVED FROM THE ENVELOPE

  18. Characterization of Human CD8 T Cell Responses in Dengue Virus-Infected Patients from India

    OpenAIRE

    Chandele, Anmol; Sewatanon, Jaturong; Gunisetty, Sivaram; Singla, Mohit; Onlamoon, Nattawat; Akondy, Rama S.; Kissick, Haydn Thomas; Nayak, Kaustuv; Reddy, Elluri Seetharami; Kalam, Haroon; Kumar, Dhiraj; Verma, Anil; Panda, Harekrushna; Wang, Siyu; Angkasekwinai, Nasikarn

    2016-01-01

    ABSTRACT Epidemiological studies suggest that India has the largest number of dengue virus infection cases worldwide. However, there is minimal information about the immunological responses in these patients. CD8 T cells are important in dengue, because they have been implicated in both protection and immunopathology. Here, we provide a detailed analysis of HLA-DR+ CD38+ and HLA-DR− CD38+ effector CD8 T cell subsets in dengue patients from India and Thailand. Both CD8 T cell subsets expanded ...

  19. Complete genetic characterization of a Brazilian dengue virus type 3 strain isolated from a fatal outcome

    Directory of Open Access Journals (Sweden)

    Marize Pereira Miagostovich

    2006-05-01

    Full Text Available We have determined the complete nucleotide and the deduced amino acid sequences of Brazilian dengue virus type 3 (DENV-3 from a dengue case with fatal outcome, which occurred during an epidemic in the state of Rio de Janeiro, Brazil, in 2002. This constitutes the first complete genetic characterization of a Brazilian DENV-3 strain since its introduction into the country in 2001. DENV-3 was responsible for the most severe dengue epidemic in the state, based on the highest number of reported cases and on the severity of clinical manifestations and deaths reported.

  20. Optical diagnosis of dengue virus infection in human blood serum using Raman spectroscopy

    Science.gov (United States)

    Saleem, M.; Bilal, M.; Anwar, S.; Rehman, A.; Ahmed, M.

    2013-03-01

    We present the optical diagnosis of dengue virus infection in human blood serum using Raman spectroscopy. Raman spectra were acquired from 18 blood serum samples using a laser at 532 nm as the excitation source. A multivariate regression model based on partial least-squares regression is developed that uses Raman spectra to predict dengue infection with leave-one-sample-out cross validation. The prediction of dengue infection by our model yields correlation coefficient r2 values of 0.9998 between the predicted and reference clinical results. The model was tested for six unknown human blood sera and found to be 100% accurate in accordance with the clinical results.

  1. Mitochondrial and bioenergetic dysfunction in human hepatic cells infected with dengue 2 virus

    OpenAIRE

    El-Bacha, Tatiana; Midlej, Victor; Silva, Ana Paula Pereira da; COSTA,LEANDRO SILVA DA; Benchimol, Marlene; Galina, Antonio; POIAN,ANDREA T. DA

    2007-01-01

    Mitochondrial and bioenergetic dysfunction in human hepatic cells infected with dengue 2 virus correspondence: Corresponding author. Fax: +55 21 22708647. (El-Bacha, Tatiana) (El-Bacha, Tatiana) Laboratorio de Bioquimica de Virus, Instituto de Bioquimica Medica, Universidade Federal do Rio de Janeiro - RJ-Brasil--> , Av. Bauhinia n? 400 ? CCS Bloco H 2? andar--> , sala 22. Ilha do Governador--> ...

  2. Molecular mechanisms of dengue virus infection : cell tropism, antibody-dependent enhancement, and cytokines

    NARCIS (Netherlands)

    Flipse, Jacobus

    2015-01-01

    Dengue is the most prevalent mosquito-borne viral disease in humans. Although most infections occur in the (sub)tropical areas, recent outbreaks in Italy and Madeira indicate that the virus is spreading into Europe. Despite its relevance, no vaccine or medications are available against this virus. T

  3. First Complete Genome Sequence of a Chikungunya Virus Strain Isolated from a Patient Diagnosed with Dengue Virus Infection in Malaysia

    Science.gov (United States)

    Gan, Han Ming; Rohani, Ahmad

    2016-01-01

    Here, we report the complete genome sequence of a chikungunya virus coinfection strain isolated from a dengue virus serotype 2-infected patient in Malaysia. This coinfection strain was determined to be of the Asian genotype and contains a novel insertion in the nsP3 gene. PMID:27563048

  4. Characterization of the early events in dengue virus cell entry by biochemical assays and single-virus tracking

    NARCIS (Netherlands)

    van der Schaar, Hilde M.; Rust, Michael J.; Waarts, Barry-Lee; van der Ende-Metselaarl, Heidi; Kuhn, Richard J.; Wilschut, Jan; Zhuang, Xiaowei; Smit, Jolanda M.

    2007-01-01

    In this study, we investigated the cell entry characteristics of dengue virus (DENV) type 2 strain SI on mosquito, BHK-15, and BS-C-1 cells. The concentration of virus particles measured by biochemical assays was found to be substantially higher than the number of infectious particles determined by

  5. Genomic approaches for understanding dengue: insights from the virus, vector, and host.

    Science.gov (United States)

    Sim, Shuzhen; Hibberd, Martin L

    2016-03-02

    The incidence and geographic range of dengue have increased dramatically in recent decades. Climate change, rapid urbanization and increased global travel have facilitated the spread of both efficient mosquito vectors and the four dengue virus serotypes between population centers. At the same time, significant advances in genomics approaches have provided insights into host-pathogen interactions, immunogenetics, and viral evolution in both humans and mosquitoes. Here, we review these advances and the innovative treatment and control strategies that they are inspiring.

  6. The Influence of Multiple Host Contacts on the Acquisition and Transmission of Dengue-2 Virus

    Science.gov (United States)

    1993-01-01

    live through the extrinsic incubation period. Therefore, Iap is an estimate of the daily number of infective ft. agg3=i generated from a single human...interrupted attempts to blood food on an active host. Such interruptions could include interruption of probing. Conversely, there is reason to believe that AS...induces life long immunity in humans. In areas where dengue viruses are prevalent, dengue fever is usually a childhood disease and most of the adult

  7. Pictorial Keys for the Identification of Mosquitoes (Diptera: Culicidae) Associated With Dengue Virus Transmission

    Science.gov (United States)

    2004-08-03

    mediovittatus. American Journal of Tropical Medicine and Hygiene, 39, 218–222. Gubler, D.J. (1997) Dengue and dengue hemorrhagic fever: its history and...Culicidae). Insecta Koreana, 19(1), 1–130. © 2004 Magnolia Press 9KEY TO MOSQUITOES 589...virus in Yap State, Federated States of Micronesia, and implication of Aedes hensilli as an epidemic vector. American Journal of Tropical Medicine

  8. Evidence of dengue virus transmission and factors associated with the presence of anti-dengue virus antibodies in humans in three major towns in Cameroon.

    Directory of Open Access Journals (Sweden)

    Maurice Demanou

    2014-07-01

    Full Text Available Dengue is not well documented in Africa. In Cameroon, data are scarce, but dengue infection has been confirmed in humans. We conducted a study to document risk factors associated with anti-dengue virus Immunoglobulin G seropositivity in humans in three major towns in Cameroon.A cross sectional survey was conducted in Douala, Garoua and Yaounde, using a random cluster sampling design. Participants underwent a standardized interview and were blood sampled. Environmental and housing characteristics were recorded. Randomized houses were prospected to record all water containers, and immature stages of Aedes mosquitoes were collected. Sera were screened for anti-dengue virus IgG and IgM antibodies. Risk factors of seropositivity were tested using logistic regression methods with random effects. Anti-dengue IgG were found from 61.4% of sera in Douala (n = 699, 24.2% in Garoua (n = 728 and 9.8% in Yaounde (n = 603. IgM were found from 0.3% of Douala samples, 0.1% of Garoua samples and 0.0% of Yaounde samples. Seroneutralization on randomly selected IgG positive sera showed that 72% (n = 100 in Douala, 80% (n = 94 in Garoua and 77% (n = 66 in Yaounde had antibodies specific for dengue virus serotype 2 (DENV-2. Age, temporary house walls materials, having water-storage containers, old tires or toilets in the yard, having no TV, having no air conditioning and having travelled at least once outside the city were independently associated with anti-dengue IgG positivity in Douala. Age, having uncovered water containers, having no TV, not being born in Garoua and not breeding pigs were significant risk factors in Garoua. Recent history of malaria, having banana trees and stagnant water in the yard were independent risk factors in Yaounde.In this survey, most identified risk factors of dengue were related to housing conditions. Poverty and underdevelopment are central to the dengue epidemiology in Cameroon.

  9. Susceptibility of Florida Aedes aegypti and Aedes albopictus to dengue viruses from Puerto Rico.

    Science.gov (United States)

    Alto, Barry W; Smartt, Chelsea T; Shin, Dongyoung; Bettinardi, David; Malicoate, Jolene; Anderson, Sheri L; Richards, Stephanie L

    2014-12-01

    Locally acquired dengue cases in the continental U.S. are rare. However, outbreaks of dengue-1 during 2009, 2010, and 2013 in Florida and dengue-1 and -2 in Texas suggest vulnerability to transmission. Travel and commerce between Puerto Rico and the U.S. mainland is common, which may pose a risk for traveler-imported dengue cases. Mosquitoes were collected in Florida and used to evaluate their susceptibility to dengue viruses (DENV) from Puerto Rico. Aedes aegypti and Ae. albopictus were susceptible to virus infection with DENV-1 and -2. No significant differences were observed in rates of midgut infection or dissemination between Ae. aegypti or Ae. albopictus for DENV-1 (6-14%). Aedes aegypti was significantly more susceptible to midgut infection with DENV-2 than Ae. albopictus (Ae. aegypti, ∼28%; Ae. albopictus, ∼9%). The dissemination rate with dengue-2 virus for Ae. aegypti (23%) was greater than Ae. albopictus (0%), suggesting that Ae. albopictus is not likely to be an important transmitter of the DENV-2 isolate from Puerto Rico. These results are discussed in light of Florida's vulnerability to DENV transmission.

  10. Virus de dengue en personas asintomáticas del poblado de Yariguá

    Directory of Open Access Journals (Sweden)

    Meidis del Rio Bolmey

    2014-08-01

    Full Text Available Se realizó un estudio observacional descriptivo de corte transversal, para determinar la seroprevalencia de anticuerpos Inmunoglobulinas M (IgM Dengue en personas que tuvieron una infección asintomática por el virus del dengue, en la localidad de Yariguá en el municipio Las Tunas, Cuba, donde se presentó un brote en el período de diciembre 2006 a enero 2007. Se analizaron 156 muestras de personas asintomáticas. Se realizó interrogatorio a los pacientes y la detección de IgM Dengue, utilizando la técnica UMELISA (del inglés Ultra Micro Enzyme-Linked ImmunoSorbent Assay. En los resultados se obtuvo que 60 de las personas asintomáticas fueron infectadas con el virus del dengue, prevaleciendo el sexo masculino y los convivientes con los enfermos de dengue. La seroprevalencia de la infección en personas asintomáticas fue de 38,5% y los riesgos de contraer la infección ascendieron a 10,7 por cada mil habitantes de la localidad de Yariguá. Se concluyó que el riesgo de seroprevalencia del virus del dengue en la población fue cuatro veces mayor que el identificado por los sistemas de vigilancia

  11. Differential Oxidative Stress Induced by Dengue Virus in Monocytes from Human Neonates, Adult and Elderly Individuals

    Science.gov (United States)

    Valero, Nereida; Mosquera, Jesús; Añez, Germán; Levy, Alegria; Marcucci, Rafael; de Mon, Melchor Alvarez

    2013-01-01

    Changes in immune response during lifespan of man are well known. These changes involve decreased neonatal and elderly immune response. In addition, it has been shown a relationship between immune and oxidative mechanisms, suggesting that altered immune response could be associated to altered oxidative response. Increased expression of nitric oxide (NO) has been documented in dengue and in monocyte cultures infected with different types of dengue virus. However, there is no information about the age-dependent NO oxidative response in humans infected by dengue virus. In this study, monocyte cultures from neonatal, elderly and adult individuals (n = 10 each group) were infected with different dengue virus types (DENV- 1 to 4) and oxidative/antioxidative responses and apoptosis were measured at days 1 and 3 of culture. Increased production of NO, lipid peroxidation and enzymatic and nonenzymatic anti-oxidative responses in dengue infected monocyte cultures were observed. However, neonatal and elderly monocytes had lower values of studied parameters when compared to those in adult-derived cultures. Apoptosis was present in infected monocytes with higher values at day 3 of culture. This reduced oxidant/antioxidant response of neonatal and elderly monocytes could be relevant in the pathogenesis of dengue disease. PMID:24069178

  12. Differential oxidative stress induced by dengue virus in monocytes from human neonates, adult and elderly individuals.

    Directory of Open Access Journals (Sweden)

    Nereida Valero

    Full Text Available Changes in immune response during lifespan of man are well known. These changes involve decreased neonatal and elderly immune response. In addition, it has been shown a relationship between immune and oxidative mechanisms, suggesting that altered immune response could be associated to altered oxidative response. Increased expression of nitric oxide (NO has been documented in dengue and in monocyte cultures infected with different types of dengue virus. However, there is no information about the age-dependent NO oxidative response in humans infected by dengue virus. In this study, monocyte cultures from neonatal, elderly and adult individuals (n = 10 each group were infected with different dengue virus types (DENV- 1 to 4 and oxidative/antioxidative responses and apoptosis were measured at days 1 and 3 of culture. Increased production of NO, lipid peroxidation and enzymatic and nonenzymatic anti-oxidative responses in dengue infected monocyte cultures were observed. However, neonatal and elderly monocytes had lower values of studied parameters when compared to those in adult-derived cultures. Apoptosis was present in infected monocytes with higher values at day 3 of culture. This reduced oxidant/antioxidant response of neonatal and elderly monocytes could be relevant in the pathogenesis of dengue disease.

  13. Antiviral activity of Thiosemicarbazones derived from α-amino acids against Dengue virus.

    Science.gov (United States)

    Padmanabhan, Padmapriya; Khaleefathullah, Sheriff; Kaveri, Krishansamy; Palani, Gunasekaran; Ramanathan, Giriprasath; Thennarasu, Sathiah; Tirichurapalli Sivagnanam, Uma

    2017-03-01

    The endemicity and seasonal outbreaks of Dengue disease in most tropical and subtropical countries underscores an urgent need to develop effective prevention and control measures. Development of a Dengue vaccine, which is complicated by the Antibody Dependent Enhancement effect (ADE), a viral inhibitor, seems prudent as it would inhibit the spread of the virus. In vitro methods such as MTT assay and plaque formation unit reduction assays were employed for screening the viral inhibitory property of α-amino acid based Thiosemicarbazides. The results elicits that at concentrations not exceeding the maximum non cytotoxic concentration (MNCC), these compounds completely prevented Dengue virus infection in vero cells as indicated by the absence of cytopathic effects in a dose-dependent manner. The high potency of Bz-Trp-TSC against all four types of Dengue virus infection elevates Thiosemicarbazide as a lead antiviral agent for Dengue disease. Screening small molecules for antiviral activity against the most rapidly spreading mosquito-borne viral disease is being explored by several research groups. Our findings would help to augment the efforts to identify the lead compounds for antiviral therapy to combat the Dengue disease. J. Med. Virol. 89:546-552, 2017. © 2016 Wiley Periodicals, Inc.

  14. Coinfection with influenza A(H1N1)pdm09 and dengue virus in fatal cases

    Science.gov (United States)

    Perdigão, Anne Carolinne Bezerra; Ramalho, Izabel Letícia Cavalcante; Guedes, Maria Izabel Florindo; Braga, Deborah Nunes Melo; Cavalcanti, Luciano Pamplona Góes; de Melo, Maria Elisabeth Lisboa; Araújo, Rafael Montenegro de Carvalho; Lima, Elza Gadelha; da Silva, Luciene Alexandre Bié; Araújo, Lia de Carvalho; Araújo, Fernanda Montenegro de Carvalho

    2016-01-01

    Abstract We report on four patients with fatal influenza A(H1N1)pdm09 and dengue virus coinfections. Clinical, necropsy and histopathologic findings presented in all cases were characteristic of influenza-dengue coinfections, and all were laboratory-confirmed for both infections. The possibility of influenza and dengue coinfection should be considered in locations where these two viruses’ epidemic periods coincide to avoid fatal outcomes. Dengue is a mosquito-borne viral infection caused by one of the four dengue viruses (DENV-1 to 4). Each of these viruses is capable of causing nonspecific febrile illnesses, classic dengue fever and dengue haemorrhagic fever (Gubler 1998). As a result, dengue is often difficult to diagnose clinically, especially because peak dengue season often coincides with that of other common febrile illnesses in tropical regions (Chacon et al. 2015). In April 2009, a new virus, influenza A/H1N1/pandemic (FluA/H1N1/09pdm), caused a severe outbreak in Mexico. The virus quickly spread throughout the world, and in June 2009, the World Health Organization declared a pandemic (WHO 2010). In Brazil, the first laboratory confirmed case of FluA/H1N1/09pdm was in July 2009 (Pires Neto et al. 2013). The state of Ceará, in Northeast Brazil, is a dengue endemic area. In this state, the virus influenza A(H1N1)pdm09 has circulated since 2009, and through the first half of 2012, 11 deaths caused by the virus were confirmed (Pires Neto et al. 2013). The influenza and dengue seasons in Ceará overlap, which led to diagnostic difficulties. We report four cases of laboratory-confirmed coinfection of deadly influenza A(H1N1)pdm09 with DENV, which occurred during the dengue and influenza season in 2012 and 2013 in Ceará. PMID:27598244

  15. The effect of temperature and humidity on dengue virus propagation in Aedes aegypti mosquitos.

    Science.gov (United States)

    Thu, H M; Aye, K M; Thein, S

    1998-06-01

    The effect of temperature and relative humidity on dengue virus propagation in the mosquito as one of the possible contributing factors to dengue hemorrhagic fever (DHF) outbreaks was studied. Ae. aegypti mosquitos were reared under standard conditions and inoculated intrathoracically with dengue virus. Virus propagation in the mosquitos was determined at the temperature and relative humidity of all 3 seasons of Yangon and for the simulated temperature and relative humidity of Singapore. The virus propagation was detected by direct fluorescent antibody technique (DFAT) with mosquito head squash and the virus titer was determined by plaque forming unit test (PFUT) in baby hamster kidney-21 cells. The results show that the infected mosquitos kept under the conditions of the rainy season and under the simulated conditions of Singapore had a significantly higher virus titer (p=<0.05) when compared with the other 2 seasons of Yangon. So it is thought that the temperature and relative humidity of the rainy season of Yangon and that of Singapore favors dengue virus propagation in the mosquito and is one of the contributing factors to the occurence of DHF outbreaks.

  16. PEMERIKSAAN VIRUS DENGUE-3 PADA NYAMUK Aedes aegypti YANG DIINFEKSI SECARA INTRATHORAKAL DENGAN TEKNIK IMUNOSITOKIMIA MENGGUNAKAN ANTIBODI DSSE10

    Directory of Open Access Journals (Sweden)

    Dyah Widiastuti

    2013-09-01

    Full Text Available ABSTRACTDengue viruses, globally the most prevalent arboviruses, are transmitted to humans by persistently infectedAedes mosquitoes. The most important vector of Dengue virus is the mosquito Ae.aegypti, which should be the main targetof surveillance and control activities. Virologic surveillance for dengue viruses in its vector has been used as an earlywarning system to predict outbreaks. Detection of Dengue virus antigen in mosquito head squash usingimmunocytochemical streptavidin biotin peroxidase complex (SBPC assay is an alternative method for dengue vectorsurveillance. The study aimed to develope immunocytochemical SBPC assay to detect Dengue virus infection in headsquash of Ae.aegypti. The study design was experimental. Artificially-infected adult Ae. aegypti mosquitoes of DENV 3were used as infectious samples and non-infected adult Ae. aegypti mosquitoes were used as normal ones. Theimmunocytochemical SBPC assay using monoclonal antibody DSSE10 then was applied in mosquito head squash todetect Dengue virus antigen. The results were analyzed by descriptive analysis. The immunocytochemical SBPC assaycan detect Dengue virus antigen in mosquito head squash at day 2 postinfection. There are some false positive resultsfound in immunocytochemical SBPC assay.Key Word: Dengue, immunocytochemistry, DSSE10

  17. Targeting of highly conserved Dengue virus sequences with anti-Dengue virus trans-splicing group I introns

    Directory of Open Access Journals (Sweden)

    Fraser Tresa S

    2010-11-01

    Full Text Available Abstract Background Dengue viruses (DENV are one of the most important viral diseases in the world with approximately 100 million infections and 200,000 deaths each year. The current lack of an approved tetravalent vaccine and ineffective insecticide control measures warrant a search for alternatives to effectively combat DENV. The trans-splicing variant of the Tetrahymena thermophila group I intron catalytic RNA, or ribozyme, is a powerful tool for post-transcriptional RNA modification. The nature of the ribozyme and the predictability with which it can be directed makes it a powerful tool for modifying RNA in nearly any cell type without the need for genome-altering gene therapy techniques or dependence on native cofactors. Results Several anti-DENV Group I trans-splicing introns (αDENV-GrpIs were designed and tested for their ability to target DENV-2 NGC genomes in situ. We have successfully targeted two different uracil bases on the positive sense genomic strand within the highly conserved 5'-3' cyclization sequence (CS region common to all serotypes of DENV with our αDENV-GrpIs. Our ribozymes have demonstrated ability to specifically trans-splice a new RNA sequence downstream of the targeted site in vitro and in transfected insect cells as analyzed by firefly luciferase and RT-PCR assays. The effectiveness of these αDENV-GrpIs to target infecting DENV genomes is also validated in transfected or transformed Aedes mosquito cell lines upon infection with unattenuated DENV-2 NGC. Conclusions Analysis shows that our αDENV-GrpIs have the ability to effectively trans-splice the DENV genome in situ. Notably, these results show that the αDENV-GrpI 9v1, designed to be active against all forms of Dengue virus, effectively targeted the DENV-2 NGC genome in a sequence specific manner. These novel αDENV-GrpI introns provide a striking alternative to other RNA based approaches for the transgenic suppression of DENV in transformed mosquito cells and

  18. An adjuvanted, tetravalent dengue virus purified inactivated vaccine candidate induces long-lasting and protective antibody responses against dengue challenge in rhesus macaques.

    Science.gov (United States)

    Fernandez, Stefan; Thomas, Stephen J; De La Barrera, Rafael; Im-Erbsin, Rawiwan; Jarman, Richard G; Baras, Benoît; Toussaint, Jean-François; Mossman, Sally; Innis, Bruce L; Schmidt, Alexander; Malice, Marie-Pierre; Festraets, Pascale; Warter, Lucile; Putnak, J Robert; Eckels, Kenneth H

    2015-04-01

    The immunogenicity and protective efficacy of a candidate tetravalent dengue virus purified inactivated vaccine (TDENV PIV) formulated with alum or an Adjuvant System (AS01, AS03 tested at three different dose levels, or AS04) was evaluated in a 0, 1-month vaccination schedule in rhesus macaques. One month after dose 2, all adjuvanted formulations elicited robust and persisting neutralizing antibody titers against all four dengue virus serotypes. Most of the formulations tested prevented viremia after challenge, with the dengue serotype 1 and 2 virus strains administered at 40 and 32 weeks post-dose 2, respectively. This study shows that inactivated dengue vaccines, when formulated with alum or an Adjuvant System, are candidates for further development.

  19. Membrane interacting regions of Dengue virus NS2A protein.

    Science.gov (United States)

    Nemésio, Henrique; Villalaín, José

    2014-08-28

    The Dengue virus (DENV) NS2A protein, essential for viral replication, is a poorly characterized membrane protein. NS2A displays both protein/protein and membrane/protein interactions, yet neither its functions in the viral cycle nor its active regions are known with certainty. To highlight the different membrane-active regions of NS2A, we characterized the effects of peptides derived from a peptide library encompassing this protein's full length on different membranes by measuring their membrane leakage induction and modulation of lipid phase behavior. Following this initial screening, one region, peptide dens25, had interesting effects on membranes; therefore, we sought to thoroughly characterize this region's interaction with membranes. This peptide presents an interfacial/hydrophobic pattern characteristic of a membrane-proximal segment. We show that dens25 strongly interacts with membranes that contain a large proportion of lipid molecules with a formal negative charge, and that this effect has a major electrostatic contribution. Considering its membrane modulating capabilities, this region might be involved in membrane rearrangements and thus be important for the viral cycle.

  20. Differential requirements in endocytic trafficking for penetration of dengue virus.

    Directory of Open Access Journals (Sweden)

    Eliana G Acosta

    Full Text Available The entry of DENV into the host cell appears to be a very complex process which has been started to be studied in detail. In this report, the route of functional intracellular trafficking after endocytic uptake of dengue virus serotype 1 (DENV-1 strain HW, DENV-2 strain NGC and DENV-2 strain 16681 into Vero cells was studied by using a susceptibility to ammonium chloride assay, dominant negative mutants of several members of the family of cellular Rab GTPases that participate in regulation of transport through endosome vesicles and immunofluorescence colocalization. Together, the results presented demonstrate that in spite of the different internalization route among viral serotypes in Vero cells and regardless of the viral strain, DENV particles are first transported to early endosomes in a Rab5-dependent manner. Then a Rab7-dependent pathway guides DENV-2 16681 to late endosomes, whereas a yet unknown sorting event controls the transport of DENV-2 NGC, and most probably DENV-1 HW, to the perinuclear recycling compartments where fusion membrane would take place releasing nucleocapsid into the cytoplasm. Besides the demonstration of a different intracellular trafficking for two DENV-2 strains that shared the initial clathrin-independent internalization route, these studies proved for the first time the involvement of the slow recycling pathway for DENV-2 productive infection.

  1. Nanoscale optofluidic sensor arrays for Dengue virus detection

    Science.gov (United States)

    Mandal, Sudeep; Akhmechet, Roman; Chen, Likun; Nugen, Sam; Baeumner, Antje; Erickson, David

    2007-09-01

    Here we present our work towards the development of Nanoscale Optofluidic Sensor Arrays (NOSA), which is an optofluidic architecture for performing label free, highly parallel, detections of biomolecular interactions. The approach is based on the use of optically resonant devices whose resonant wavelength is shifted due to a local change in refractive index caused by a positive binding event between a surface bound molecule and it solution phase target. A special two stage micro-/nanofluidics architecture is used to first functionalize the devices and then to deliver the targets. Two variants of the NOSA will be presented here. The first approach utilizes a 1D resonant cavity in a 1D silicon-on-insulator (SOI) waveguide with a unique differential size functionalization approach. This approach allows binding events at one or at a combination of the many sensing sites which causes a unique shift in the output resonator spectrum. The latter approach consists of a SOI waveguide evanescently coupled to multiple 1-D photonic crystal resonators of different sizes along the length, each of which is functionalized with a different oligonucleotide probe. These devices have an extremely low limit of detection and are compatible with aqueous environments. The primary advantage of these devices over existing technology is that it combines the sensitivity (limit of detection) of nanosensor technology with the parallelism of the microarray type format. Our initial application is in the detection of viral RNA of Dengue virus.

  2. [Subtypes of dengue virus serotypes 2, 3 and 4 isolated in Santander District, Colombia].

    Science.gov (United States)

    Cortés, Fabián M; Gómez, Sergio Y; Ocazionez, Raquel E

    2007-01-01

    Virus serotypes 2, 3 and 4 that had circulated in Santander District, Colombia in the period 1998-2004 were analyzed. Identifying the subtype of a dengue virus serotype is a useful tool for surveillance of severe risk factors because the strain potential to cause hemorrhagic dengue makes the difference among them. Simultaneous sequence amplification technique known as restriction site specific-polymerase chain reaction (RSS-PCR) was used to determine the subtype by comparing the electrophoretic pattern of the local isolate to the reference virus. Virus serotype 2 corresponded to subtype A similar to the one isolated in Thailand (1996) and to the other isolated in Porto Rico (1986); virus serotypes 3 were of subtype C like the virus found in Sri Lanka (1990), Honduras (1995) and Porto Rico (2000); virus serotypes 4 were a variant of subtype B similar to a virus from Porto Rico (1987) and to another virus from Tahiti (1985). The study confirmed the presence in Colombia of dengue virus subtypes circulating now in the Americas.

  3. Evidence for the Inhibition of Dengue Virus Binding in the Presence of Silver Nanoparticles

    Science.gov (United States)

    2015-03-26

    pretreatment with AgNP (6-10nm, 25µg/mL). These results suggest that similarly to other viruses , DENV2 can be inhibited at the first stage of the virus ...closely related viruses known as dengue virus -1 through -4 (DENV1-DENV4). A fifth serotype (DENV5) was discovered from a serological sample from 2007...various viruses at the binding and entry phase of viral replication. However, this is the first time a Group IV virus (ss(-)RNA) has been inhibited by

  4. STUDY OF CLINICAL PROFILE OF DENGUE FEVER WITH SPECIAL REFERENCE TO ACUTE COMPLICATIONS

    Directory of Open Access Journals (Sweden)

    Keshava

    2014-02-01

    Full Text Available ABSTRACT: Dengue is the arthropode borne viral infection transmitted by mosquitoes to humans. AIM: To study the various clinical manifestations and acute complications of dengue fever. METHODS: 100 cases of confirmed dengue infection admitted to KIMS, Bangalore between December 2009 and September 2011 were studied. A detailed clinical history and physical examination was done and baseline investigations were performed. The cases were followed-up daily for the clinical and laboratory parameters and were treated according to WHO guidelines. The data related to each of these cases was collected, compiled and analyzed. RESULTS: of the total 100 cases there were 61 male and 39 female. Age group of 21-30 (41 was most commonly affected Maximum number of patients was seen in the September, October, august, July. Commonest presentation was Fever (100% followed by Headache (78%, Myalgia (70%, Arthralgia (66%, low back ache (60%. On examination patients found to have icterus (22%, bleeding spots (26%, rashes (50%, Splenomegaly (18%, Hepatomegaly (15% and Ascites (9%, pleural effusion (16%, crepitations (7%. Platelet count was not very well correlated with the bleeding tendencies. Incidence of DHF was more with secondary Dengue infection than the primary dengue infection. The frequency of complications was high in the patients with secondary dengue infection than the primary infection. CONCLUSION: In our present study classical dengue fever was most common presentation followed by DHF and DSS. Hypotension, hemorrhagic spots, positive tourniquet test, jaundice, pleural effusion, ascites, neck stiffness are the common findings on examination associated with complicated forms of dengue. Bleeding, shock, hepatitis, polyserositis, meningitis, pneumonia are the complications seen in severe forms. On investigation Deranged liver function test, renal function test, secondary dengue infection, thickened gall bladder wall, hepatosplenomegaly on ultrasound abdomen

  5. Evaluation of antiviral activities of Houttuynia cordata Thunb. extract, quercetin, quercetrin and cinanserin on murine coronavirus and dengue virus infection

    Institute of Scientific and Technical Information of China (English)

    K. H. Chiow; M. C. Phoon; Thomas Putti; Benny K. H. Tan; Vincent T. Chow

    2016-01-01

    Objective: To evaluate the in vitro activities of the ethyl acetate (EA) fraction of Houttuynia cordata (H. cordata) Thunb. (Saururaceae) and three of its constituent flavonoids (quercetin, quercitrin and rutin) against murine coronavirus and dengue virus (DENV). Methods: The antiviral activities of various concentrations of the EA fraction of H. cordata and flavonoids were assessed using virus neutralization tests against mouse hepatitis virus (MHV) and DENV type 2 (DENV-2). Cinanserin hydrochloride was also tested against MHV. The EA fraction of H. cordata was tested for acute oral toxicity in C57BL/6 mice. Results: The EA fraction of H. cordata inhibited viral infectivity up to 6 d. Cinanserin hydrochloride was able to inhibit MHV for only 2 d. The 50% inhibitory concentrations (IC50) of the EA fraction of H. cordata added before the viral adsorption stage were 0.98 μg/mL for MHV and 7.50 μg/mL for DENV-2 with absence of cytotoxicity. The mice fed with the EA fraction up to 2 000 mg/kg did not induce any signs of acute toxicity, with normal histological features of major organs. Certain flavonoids exhibited comparatively weaker antiviral activity, notably quercetin which could inhibit both MHV and DENV-2. This was followed by quercitrin which could inhibit DENV-2 but not MHV, whereas rutin did not exert any inhibitory effect on either virus. When quercetin was combined with quercitrin, enhancement of anti-DENV-2 activity and reduced cytotoxicity were observed. However, the synergistic efficacy of the flavonoid combination was still less than that of the EA fraction. Conclusions: The compounds in H. cordata contribute to the superior antiviral efficacy of the EA fraction which lacked cytotoxicity in vitro and acute toxicity in vivo. H. cordata has much potential for the development of antiviral agents against coronavirus and dengue infections.

  6. Binding of a neutralizing antibody to dengue virus alters the arrangement of surface glycoproteins

    Energy Technology Data Exchange (ETDEWEB)

    Lok, Shee-Mei; Kostyuchenko, Victor; Nybakken, Grant E.; Holdaway, Heather A.; Battisti, Anthony J.; Sukupolvi-Petty, Soila; Sedlak, Dagmar; Fremont, Daved H.; Chipman, Paul R.; Roehrig, John T.; Diamond, Michael S.; Kuhn, Richard J.; Rossmann, Michael G. (Purdue); (WU-MED); (CDC)

    2008-04-02

    The monoclonal antibody 1A1D-2 has been shown to strongly neutralize dengue virus serotypes 1, 2 and 3, primarily by inhibiting attachment to host cells. A crystal structure of its antigen binding fragment (Fab) complexed with domain III of the viral envelope glycoprotein, E, showed that the epitope would be partially occluded in the known structure of the mature dengue virus. Nevertheless, antibody could bind to the virus at 37 degrees C, suggesting that the virus is in dynamic motion making hidden epitopes briefly available. A cryo-electron microscope image reconstruction of the virus:Fab complex showed large changes in the organization of the E protein that exposed the epitopes on two of the three E molecules in each of the 60 icosahedral asymmetric units of the virus. The changes in the structure of the viral surface are presumably responsible for inhibiting attachment to cells.

  7. Small-molecule inhibitors of dengue-virus entry.

    Directory of Open Access Journals (Sweden)

    Aaron G Schmidt

    Full Text Available Flavivirus envelope protein (E mediates membrane fusion and viral entry from endosomes. A low-pH induced, dimer-to-trimer rearrangement and reconfiguration of the membrane-proximal "stem" of the E ectodomain draw together the viral and cellular membranes. We found stem-derived peptides from dengue virus (DV bind stem-less E trimer and mimic the stem-reconfiguration step in the fusion pathway. We adapted this experiment as a high-throughput screen for small molecules that block peptide binding and thus may inhibit viral entry. A compound identified in this screen, 1662G07, and a number of its analogs reversibly inhibit DV infectivity. They do so by binding the prefusion, dimeric E on the virion surface, before adsorption to a cell. They also block viral fusion with liposomes. Structure-activity relationship studies have led to analogs with submicromolar IC₉₀s against DV2, and certain analogs are active against DV serotypes 1,2, and 4. The compounds do not inhibit the closely related Kunjin virus. We propose that they bind in a previously identified, E-protein pocket, exposed on the virion surface and although this pocket is closed in the postfusion trimer, its mouth is fully accessible. Examination of the E-trimer coordinates (PDB 1OK8 shows that conformational fluctuations around the hinge could open the pocket without dissociating the trimer or otherwise generating molecular collisions. We propose that compounds such as 1662G07 trap the sE trimer in a "pocket-open" state, which has lost affinity for the stem peptide and cannot support the final "zipping up" of the stem.

  8. Purification and crystallization of dengue and West Nile virus NS2B–NS3 complexes

    Energy Technology Data Exchange (ETDEWEB)

    D’Arcy, Allan, E-mail: allan.darcy@novartis.com; Chaillet, Maxime; Schiering, Nikolaus; Villard, Frederic [Novartis Institutes of Biomedical Research, Protease Platform, Klybeckstrasse 144, CH 4002 Basel (Switzerland); Lim, Siew Pheng [Novartis Institutes of Tropical Diseases (Singapore); Lefeuvre, Peggy [Novartis Institutes of Biomedical Research, Protease Platform, Klybeckstrasse 144, CH 4002 Basel (Switzerland); Erbel, Paul [Novartis Institutes of Biomedical Research, Protease Platform, Klybeckstrasse 144, CH 4002 Basel (Switzerland); Novartis Institutes of Tropical Diseases (Singapore)

    2006-02-01

    Crystals of dengue serotype 2 and West Nile virus NS2B–NS3 protease complexes have been obtained and the crystals of both diffract to useful resolution. Sample homogeneity was essential for obtaining X-ray-quality crystals of the dengue protease. Controlled proteolysis produced a crystallizable fragment of the apo West Nile virus NS2B–NS3 and crystals were also obtained in the presence of a peptidic inhibitor. Both dengue and West Nile virus infections are an increasing risk to humans, not only in tropical and subtropical areas, but also in North America and parts of Europe. These viral infections are generally transmitted by mosquitoes, but may also be tick-borne. Infection usually results in mild flu-like symptoms, but can also cause encephalitis and fatalities. Approximately 2799 severe West Nile virus cases were reported this year in the United States, resulting in 102 fatalities. With this alarming increase in the number of West Nile virus infections in western countries and the fact that dengue virus already affects millions of people per year in tropical and subtropical climates, there is a real need for effective medicines. A possible therapeutic target to combat these viruses is the protease, which is essential for virus replication. In order to provide structural information to help to guide a lead identification and optimization program, crystallizations of the NS2B–NS3 protease complexes from both dengue and West Nile viruses have been initiated. Crystals that diffract to high resolution, suitable for three-dimensional structure determinations, have been obtained.

  9. TEMPAT PERKEMBANGBIAKAN AEDES SPP. SEBAGAI PENULAR VIRUS DENGUE PADA BERBAGAI TEMPAT DI KOTA SUKABUMI

    Directory of Open Access Journals (Sweden)

    Dewi Nur Hodijah

    2016-05-01

    Full Text Available Cases of Dengue Hemorrhagic Fever (DHF and speed of  increased cases in Sukabumi city is highest in West Java, as it was shown by Incidence Rate (IR of Dengue virus infection in Sukabumi city in 2009 was 430 /100,000 and in 2010 reached 330 /100,000. Slope of the regression line of IR enhancement of dengue virus infection in the period 2004 - 2010 of Sukabumi City have the highest value (55.8 when compared to Cimahi (32.1 and Bandung (12.1. Environmental survey was conducted for entomology examination at home of patient with Dengue virus infection and places visited in the morning until late afternoon the week before illness. Examination results at housing obtained positive Aedes spp 36,8.7%, and 23.5% were found in public places. The results showed that the public places was a potential transmission of dengue virus infection. Results of this study showed that water reservoirs that are most numerous Aedes spp. wasbath tub. The study also reported the House Index (HI 31.55%, Container Index (CI 21.72% and Bretau Index (BI 51.46%. Threshold larvae index obtained by HI was at value 5 or moderate risk but based on CI and BI were in grades 6 means to have a high risk of transmission.

  10. How Important is Vertical Transmission of Dengue Viruses by Mosquitoes (Diptera: Culicidae)?

    Science.gov (United States)

    Grunnill, Martin; Boots, Michael

    2016-01-01

    Vertical transmission of dengue viruses by mosquitoes was discovered at the end of the late 1970s and has been suggested to be a means by which these viruses persist. However, it is unclear how widespread it is in nature, and its importance in the epidemiology of this disease is still debated. Here, we review the literature on vertical transmission and discuss its role in dengue's epidemiology and control. We conclude that given the number of studies that failed to find evidence of vertical transmission, as well as mathematical models and its mechanistic basis, it is unlikely that vertical transmission is important for the epidemiological persistence of dengue viruses. A combination of asymptomatic infection in humans and movement of people are likely to be more important determinants of dengue's persistence. We argue, however, that there may be some need for further research into the prevalence of dengue viruses in desiccated, as well as diapausing, eggs and the role of horizontal transmission through larval cannibalism.

  11. The Epidemiology, Virology and Clinical Findings of Dengue Virus Infections in a Cohort of Indonesian Adults in Western Java.

    Directory of Open Access Journals (Sweden)

    Herman Kosasih

    2016-02-01

    Full Text Available Dengue has emerged as one of the most important infectious diseases in the last five decades. Evidence indicates the expansion of dengue virus endemic areas and consequently the exponential increase of dengue virus infections across the subtropics. The clinical manifestations of dengue virus infection include sudden fever, rash, headache, myalgia and in more serious cases, spontaneous bleeding. These manifestations occur in children as well as in adults. Defining the epidemiology of dengue in a given area is critical to understanding the disease and devising effective public health strategies.Here, we report the results from a prospective cohort study of 4380 adults in West Java, Indonesia, from 2000-2004 and 2006-2009. A total of 2167 febrile episodes were documented and dengue virus infections were confirmed by RT-PCR or serology in 268 cases (12.4%. The proportion ranged from 7.6 to 41.8% each year. The overall incidence rate of symptomatic dengue virus infections was 17.3 cases/1,000 person years and between September 2006 and April 2008 asymptomatic infections were 2.6 times more frequent than symptomatic infections. According to the 1997 WHO classification guidelines, there were 210 dengue fever cases, 53 dengue hemorrhagic fever cases (including one dengue shock syndrome case and five unclassified cases. Evidence for sequential dengue virus infections was seen in six subjects. All four dengue virus serotypes circulated most years. Inapparent dengue virus infections were predominantly associated with DENV-4 infections.Dengue virus was responsible for a significant percentage of febrile illnesses in an adult population in West Java, Indonesia, and this percentage varied from year to year. The observed incidence rate during the study period was 43 times higher than the reported national or provincial rates during the same time period. A wide range of clinical severity was observed with most infections resulting in asymptomatic disease. The

  12. Recombinant Dengue virus protein NS2B alters membrane permeability in different membrane models

    OpenAIRE

    León-Juárez, Moisés; Martínez-Castillo, Macario; Shrivastava, Gaurav; García-Cordero, Julio; Villegas-Sepulveda, Nicolás; Mondragón-Castelán, Mónica; Mondragón-Flores, Ricardo; Cedillo-Barrón, Leticia

    2016-01-01

    Background One of the main phenomena occurring in cellular membranes during virus infection is a change in membrane permeability. It has been observed that numerous viral proteins can oligomerize and form structures known as viroporins that alter the permeability of membranes. Previous findings have identified such proteins in cells infected with Japanese encephalitis virus (JEV), a member of the same family that Dengue virus (DENV) belongs to (Flaviviridae). In the present work, we investiga...

  13. Virucidal activity of Colombian Lippia essential oils on dengue virus replication in vitro

    OpenAIRE

    Raquel Elvira Ocazionez; Rocio Meneses; Flor Ángela Torres; Elena Stashenko

    2010-01-01

    The inhibitory effect of Lippia alba and Lippia citriodora essential oils on dengue virus serotypes replication in vitro was investigated. The cytotoxicity (CC50) was evaluated by the MTT assay and the mode of viral inhibitory effect was investigated with a plaque reduction assay. The virus was treated with the essential oil for 2 h at 37ºC before cell adsorption and experiments were conducted to evaluate inhibition of untreated-virus replication in the presence of oil. Antiviral activity was...

  14. [Dengue virus infection in neotropical forest mammals: incidental hosts or potential reservoirs?].

    Science.gov (United States)

    Lavergne, A; Lacoste, V; Germain, A; Matheus, S; Dussart, P; Deparis, X; de Thoisy, B

    2009-08-01

    The arboviral disease with the highest human incidence in South America is dengue fever. In French Guiana, where all four dengue serotypes, i.e., DENV-1, DENV-2, DENV-3 and DENV-4, are present, the disease is endemic with epidemic outbreaks. Though previous serological studies have suggested a sylvatic cycle, involvement of wild mammals in the dengue cycle in the neotropics has never been confirmed. The purpose of this study was to search for the presence of DENV in wild animals captured at two different sites between 2001 and 2007. About 10,000 trap/nights were performed leading to the capture of 464 non-flying mammals (rodents and marsupials). In addition, mistnests placed in the same zone yielded 152 bats. Reverse transcription-polymerase chain reaction amplification to detect infection by any of the four dengue serotypes demonstrated viral RNA in the livers and/or sera of 92 captured animals. Sequence analysis of amplification products revealed that the DENV-1, DENV-3 and DENV-4 serotypes were distinct from those circulating in humans at the same periods. Analysis for DENV-2 showed that some strains were divergent from concurrent human strains but that others were identical. The latter finding suggests that wild neotropical mammals living in periurban area can be infected by dengue virus strains circulating in humans. However, further investigation will be needed to determine if neotropical mammals are incidental hosts or potential reservoirs of dengue virus.

  15. A simple method for Alexa Fluor dye labelling of dengue virus.

    Science.gov (United States)

    Zhang, Summer Li-Xin; Tan, Hwee-Cheng; Hanson, Brendon J; Ooi, Eng Eong

    2010-08-01

    Dengue virus causes frequent and cyclical epidemics throughout the tropics, resulting in significant morbidity and mortality rates. There is neither a specific antiviral treatment nor a vaccine to prevent epidemic transmission. The lack of a detailed understanding of the pathogenesis of the disease complicates these efforts. The development of methods to probe the interaction between the virus and host cells would thus be useful. Direct fluorescence labelling of virus would facilitate the visualization of the early events in virus-cell interaction. This report describes a simple method of labelling of dengue virus with Alexa Fluor succinimidyl ester dye dissolved directly in the sodium bicarbonate buffer that yielded highly viable virus after labelling. Alexa Fluor dyes have superior photostability and are less pH-sensitive than the common dyes, such as fluorescein and rhodamine, making them ideal for studies on cellular uptake and endosomal transport of the virus. The conjugation of Alexa Fluor dye did not affect the recognition of labelled dengue virus by virus-specific antibody and its putative receptors in host cells. This method could have useful applications in virological studies.

  16. Respuesta neuroinmunológica en la encefalitis asociada al virus del dengue

    OpenAIRE

    Bárbara Padilla-Docal; Daisy Wainshtok-Tomáss; José Pedro Martínez-Larrarte; Edmundo Rivero-Arias; Ana Herrera- Wainshtok; Jesús Callol-Barroso; Alberto Juan Dorta-Contreras

    2013-01-01

    El virus del dengue es un virus ARN miembro de la familia Flaviviridae, la cual incluye, además, el de la fiebre amarilla, el del Nilo del Oeste y la encefalitis japonesa. Se realizó un estudio retrospectivo con tres pacientes diagnosticados de encefalitis asociada al dengue, en cuyas muestras de suero y líquido cefalorraquídeo se cuantificaron los niveles de las clases mayores de inmunoglobulinas por inmunodifusión radial y la manosa de unión a lectina, proteína de la vía de las lectinas del...

  17. Acute otitis media and respiratory virus infections.

    Science.gov (United States)

    Ruuskanen, O; Arola, M; Putto-Laurila, A; Mertsola, J; Meurman, O; Viljanen, M K; Halonen, P

    1989-02-01

    We studied the association of acute otitis media with different respiratory virus infections in a pediatric department on the basis of epidemics between 1980 and 1985. Altogether 4524 cases of acute otitis media were diagnosed. The diagnosis was confirmed by tympanocentesis in 3332 ears. Respiratory virus infection was diagnosed during the same period in 989 patients by detecting viral antigen in nasopharyngeal mucus. There was a significant correlation between acute otitis media and respiratory virus epidemics, especially respiratory syncytial virus epidemics. There was no significant correlation between outbreaks of other respiratory viruses and acute otitis media. Acute otitis media was diagnosed in 57% of respiratory syncytial virus, 35% of influenza A virus, 33% of parainfluenza type 3 virus, 30% of adenovirus, 28% of parainfluenza type 1 virus, 18% of influenza B virus and 10% of parainfluenza type 2 virus infections. These observations show a clear association of respiratory virus infections with acute otitis media. In this study on hospitalized children Haemophilus influenzae strains were the most common bacteriologic pathogens in middle ear fluid, occurring in 19% of cases. Streptococcus pneumoniae was present in 16% and Branhamella catarrhalis in 7% of cases. There was no association between specific viruses and bacteria observed in this study.

  18. Targeting Viral Proteostasis Limits Influenza Virus, HIV, and Dengue Virus Infection.

    Science.gov (United States)

    Heaton, Nicholas S; Moshkina, Natasha; Fenouil, Romain; Gardner, Thomas J; Aguirre, Sebastian; Shah, Priya S; Zhao, Nan; Manganaro, Lara; Hultquist, Judd F; Noel, Justine; Sachs, David; Sachs, David H; Hamilton, Jennifer; Leon, Paul E; Chawdury, Amit; Tripathi, Shashank; Melegari, Camilla; Campisi, Laura; Hai, Rong; Metreveli, Giorgi; Gamarnik, Andrea V; García-Sastre, Adolfo; Greenbaum, Benjamin; Simon, Viviana; Fernandez-Sesma, Ana; Krogan, Nevan J; Mulder, Lubbertus C F; van Bakel, Harm; Tortorella, Domenico; Taunton, Jack; Palese, Peter; Marazzi, Ivan

    2016-01-19

    Viruses are obligate parasites and thus require the machinery of the host cell to replicate. Inhibition of host factors co-opted during active infection is a strategy hosts use to suppress viral replication and a potential pan-antiviral therapy. To define the cellular proteins and processes required for a virus during infection is thus crucial to understanding the mechanisms of virally induced disease. In this report, we generated fully infectious tagged influenza viruses and used infection-based proteomics to identify pivotal arms of cellular signaling required for influenza virus growth and infectivity. Using mathematical modeling and genetic and pharmacologic approaches, we revealed that modulation of Sec61-mediated cotranslational translocation selectively impaired glycoprotein proteostasis of influenza as well as HIV and dengue viruses and led to inhibition of viral growth and infectivity. Thus, by studying virus-human protein-protein interactions in the context of active replication, we have identified targetable host factors for broad-spectrum antiviral therapies.

  19. Simultaneous circulation of genotypes I and III of dengue virus 3 in Colombia

    Directory of Open Access Journals (Sweden)

    Domingo Cristina

    2008-09-01

    Full Text Available Abstract Background Dengue is a major health problem in tropical and subtropical regions. In Colombia, dengue viruses (DENV cause about 50,000 cases annually, 10% of which involve Dengue Haemorrhagic Fever/Dengue Shock Syndrome. The picture is similar in other surrounding countries in the Americas, with recent outbreaks of severe disease, mostly associated with DENV serotype 3, strains of the Indian genotype, introduced into the Americas in 1994. Results The analysis of the 3'end (224 bp of the envelope gene from 32 DENV-3 strains recently recovered in Colombia confirms the circulation of the Indian genotype, and surprisingly the co-circulation of an Asian-Pacific genotype only recently described in the Americas. Conclusion These results have important implications for epidemiology and surveillance of DENV infection in Central and South America. Molecular surveillance of the DENV genotypes infecting humans could be a very valuable tool for controlling/mitigating the impact of the DENV infection.

  20. Imaging the interaction between dengue 2 virus and human blood platelets using atomic force and electron microscopy.

    Science.gov (United States)

    Ghosh, Kanjaksha; Gangodkar, Shobha; Jain, Preksha; Shetty, Shrimati; Ramjee, Sandhya; Poddar, Pankaj; Basu, Atanu

    2008-06-01

    Thrombocytopenia is frequently associated with dengue virus infection. Host factors such as anti-platelet immunopathogenic processes have been implicated in the origin of dengue-associated thrombocytopenia but the role of dengue virus in directly interacting with platelets and altering their hemostatic property remains incompletely understood. In the present study, we examined the effect of dengue 2 virus on the morphology and physiological activation profile of normal human platelets using atomic force microscopy, electron microscopy and flowcytometry. Platelets obtained from healthy donors were exposed to a cell culture-adapted 10(4) LD(50) dengue 2 virus isolate in vitro and the subsequent effect on morphology and activation biology studied. Our results show that dengue 2 virus exposure at doses comparable to natural viremic states in human infections can activate platelets with an increase in P-selectin expression and fibrinogen-binding property. Atomic force, scanning and transmission electron microscopy also showed typical activation-related morphological changes such as altered platelet membrane architecture, degranulation, presence of filopodia and dilatation of the open canalicular system in the dengue 2 virus-exposed platelets but not in the controls. Importantly, Japanese encephalitis virus exposure at the same dose did not activate platelets or show any morphological changes. Our findings suggest that dengue 2 virus may directly interact with and activate platelets - an event that might be important in the origin of dengue-associated thrombocytopenia. Detailed molecular characterization of this effect might provide key knowledge toward better prophylaxis of the hemostatic complications of dengue disease.

  1. Identification of Zika Virus and Dengue Virus Dependency Factors using Functional Genomics

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    George Savidis

    2016-06-01

    Full Text Available The flaviviruses dengue virus (DENV and Zika virus (ZIKV are severe health threats with rapidly expanding ranges. To identify the host cell dependencies of DENV and ZIKV, we completed orthologous functional genomic screens using RNAi and CRISPR/Cas9 approaches. The screens recovered the ZIKV entry factor AXL as well as multiple host factors involved in endocytosis (RAB5C and RABGEF, heparin sulfation (NDST1 and EXT1, and transmembrane protein processing and maturation, including the endoplasmic reticulum membrane complex (EMC. We find that both flaviviruses require the EMC for their early stages of infection. Together, these studies generate a high-confidence, systems-wide view of human-flavivirus interactions and provide insights into the role of the EMC in flavivirus replication.

  2. Identification of Zika Virus and Dengue Virus Dependency Factors using Functional Genomics.

    Science.gov (United States)

    Savidis, George; McDougall, William M; Meraner, Paul; Perreira, Jill M; Portmann, Jocelyn M; Trincucci, Gaia; John, Sinu P; Aker, Aaron M; Renzette, Nicholas; Robbins, Douglas R; Guo, Zhiru; Green, Sharone; Kowalik, Timothy F; Brass, Abraham L

    2016-06-28

    The flaviviruses dengue virus (DENV) and Zika virus (ZIKV) are severe health threats with rapidly expanding ranges. To identify the host cell dependencies of DENV and ZIKV, we completed orthologous functional genomic screens using RNAi and CRISPR/Cas9 approaches. The screens recovered the ZIKV entry factor AXL as well as multiple host factors involved in endocytosis (RAB5C and RABGEF), heparin sulfation (NDST1 and EXT1), and transmembrane protein processing and maturation, including the endoplasmic reticulum membrane complex (EMC). We find that both flaviviruses require the EMC for their early stages of infection. Together, these studies generate a high-confidence, systems-wide view of human-flavivirus interactions and provide insights into the role of the EMC in flavivirus replication.

  3. Phylodynamic analysis of the emergence and epidemiological impact of transmissible defective dengue viruses.

    Science.gov (United States)

    Ke, Ruian; Aaskov, John; Holmes, Edward C; Lloyd-Smith, James O

    2013-02-01

    Intra-host sequence data from RNA viruses have revealed the ubiquity of defective viruses in natural viral populations, sometimes at surprisingly high frequency. Although defective viruses have long been known to laboratory virologists, their relevance in clinical and epidemiological settings has not been established. The discovery of long-term transmission of a defective lineage of dengue virus type 1 (DENV-1) in Myanmar, first seen in 2001, raised important questions about the emergence of transmissible defective viruses and their role in viral epidemiology. By combining phylogenetic analyses and dynamical modeling, we investigate how evolutionary and ecological processes at the intra-host and inter-host scales shaped the emergence and spread of the defective DENV-1 lineage. We show that this lineage of defective viruses emerged between June 1998 and February 2001, and that the defective virus was transmitted primarily through co-transmission with the functional virus to uninfected individuals. We provide evidence that, surprisingly, this co-transmission route has a higher transmission potential than transmission of functional dengue viruses alone. Consequently, we predict that the defective lineage should increase overall incidence of dengue infection, which could account for the historically high dengue incidence reported in Myanmar in 2001-2002. Our results show the unappreciated potential for defective viruses to impact the epidemiology of human pathogens, possibly by modifying the virulence-transmissibility trade-off, or to emerge as circulating infections in their own right. They also demonstrate that interactions between viral variants, such as complementation, can open new pathways to viral emergence.

  4. Acute transverse myelitis and subacute thyroiditis associated with dengue viral infection: A case report and literature review

    Science.gov (United States)

    Mo, Zhiming; Dong, Yaxian; Chen, Xiaolian; Yao, Huiyan; Zhang, Bin

    2016-01-01

    Acute transverse myelitis is a rare manifestation of dengue infection. To the best of our knowledge, only 6 cases of acute transverse myelitis as a manifestation of dengue infection have been reported thus far. The present study described a case of acute transverse myelitis complicated with subacute thyroiditis 6 days after the onset of dengue viral infection. In addition, the available literature was searched to identify similar previous cases. Treatment with intravenous pulse methylprednisolone immunoglobulin plasmapheresis and physiotherapy resulted in partial recovery at 3 months post-infection. In conclusion, the involvement of dengue infection should be considered in patients who develop central nervous system manifestations during or after the recovery period of dengue infection. Furthermore, since methylprednisolone and immunoglobulin are effective during the active phase of the infection, prompt diagnosis and initiation of treatment are crucial. PMID:27703498

  5. Dengue Fever with rectus sheath hematoma: a case report.

    Science.gov (United States)

    Sharma, Anurag; Bhatia, Sonia; Singh, Rajendra Pratap; Malik, Gaurav

    2014-04-01

    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.

  6. Cross-reactivity and expansion of dengue-specific T cells during acute primary and secondary infections in humans.

    Science.gov (United States)

    Friberg, Heather; Bashyam, Hema; Toyosaki-Maeda, Tomoko; Potts, James A; Greenough, Thomas; Kalayanarooj, Siripen; Gibbons, Robert V; Nisalak, Ananda; Srikiatkhachorn, Anon; Green, Sharone; Stephens, Henry A F; Rothman, Alan L; Mathew, Anuja

    2011-01-01

    Serotype-cross-reactive memory T cells responding to secondary dengue virus (DENV) infection are thought to contribute to disease. However, epitope-specific T cell responses have not been thoroughly compared between subjects with primary versus secondary DENV infection. We studied CD8(+) T cells specific for the HLA-A*1101-restricted NS3(133) epitope in a cohort of A11(+) DENV-infected patients throughout acute illness and convalescence. We compared the expansion, serotype-cross-reactivity, and activation of these cells in PBMC from patients experiencing primary or secondary infection and mild or severe disease by flow cytometry. Our results show expansion and activation of DENV-specific CD8(+) T cells during acute infection, which are predominantly serotype-cross-reactive regardless of DENV infection history. These data confirm marked T cell activation and serotype-cross-reactivity during the febrile phase of dengue; however, A11-NS3(133)-specific responses did not correlate with prior antigenic exposure or current disease severity.

  7. Intrahepatic Infiltrating NK and CD8 T Cells Cause Liver Cell Death in Different Phases of Dengue Virus Infection

    OpenAIRE

    Jui-Min Sung; Chien-Kuo Lee; Wu-Hsieh, Betty A.

    2012-01-01

    Elevated liver enzyme level is an outstanding feature in patients with dengue. However, the pathogenic mechanism of liver injury has not been clearly demonstrated. In this study, employing a mouse model we aimed to investigate the immunopathogenic mechanism of dengue liver injury. Immunocompetent C57BL/6 mice were infected intravenously with dengue virus strain 16681. Infected mice had transient viremia, detectable viral capsid gene and cleaved caspase 3 in the liver. In the mean time, NK cel...

  8. Toll-like receptor 4 polymorphisms in dengue virus-infected children.

    Science.gov (United States)

    Djamiatun, Kis; Ferwerda, Bart; Netea, Mihai G; van der Ven, André J A M; Dolmans, Wil M V; Faradz, Sultana M H

    2011-08-01

    Differential viral recognition by cells bearing Toll-like receptor 4 (TLR4) polymorphisms Asp299Gly and Thr399Ile may influence susceptibility and severity of dengue virus infection. In central Java, Indonesia, we investigated 201 children with dengue hemorrhagic fever (DHF) and 179 healthy controls. Patients and controls were mostly ethnic Javanese. A nearly complete cosegregation of the two mutations was observed. The TLR4 299/399 genotype was found in five patients and four controls. Prevalence of the TLR4 299/399 genotype did not differ significantly between controls and DHF patients or between patients with different severities of DHF. Also, vascular leakage in patients with different TLR4 genotypes did not differ. Thus, the 299/399 TLR4 haplotype has only minor influence on susceptibility and severity of complicated dengue virus infection.

  9. A DNA Microarray-Based Assay to Detect Dual Infection with Two Dengue Virus Serotypes

    Directory of Open Access Journals (Sweden)

    Alvaro Díaz-Badillo

    2014-04-01

    Full Text Available Here; we have described and tested a microarray based-method for the screening of dengue virus (DENV serotypes. This DNA microarray assay is specific and sensitive and can detect dual infections with two dengue virus serotypes and single-serotype infections. Other methodologies may underestimate samples containing more than one serotype. This technology can be used to discriminate between the four DENV serotypes. Single-stranded DNA targets were covalently attached to glass slides and hybridised with specific labelled probes. DENV isolates and dengue samples were used to evaluate microarray performance. Our results demonstrate that the probes hybridized specifically to DENV serotypes; with no detection of unspecific signals. This finding provides evidence that specific probes can effectively identify single and double infections in DENV samples.

  10. A DNA Microarray-Based Assay to Detect Dual Infection with Two Dengue Virus Serotypes

    Science.gov (United States)

    Díaz-Badillo, Alvaro; de Lourdes Muñoz, María; Perez-Ramirez, Gerardo; Altuzar, Victor; Burgueño, Juan; Mendoza-Alvarez, Julio G.; Martínez-Muñoz, Jorge P.; Cisneros, Alejandro; Navarrete-Espinosa, Joel; Sanchez-Sinencio, Feliciano

    2014-01-01

    Here; we have described and tested a microarray based-method for the screening of dengue virus (DENV) serotypes. This DNA microarray assay is specific and sensitive and can detect dual infections with two dengue virus serotypes and single-serotype infections. Other methodologies may underestimate samples containing more than one serotype. This technology can be used to discriminate between the four DENV serotypes. Single-stranded DNA targets were covalently attached to glass slides and hybridised with specific labelled probes. DENV isolates and dengue samples were used to evaluate microarray performance. Our results demonstrate that the probes hybridized specifically to DENV serotypes; with no detection of unspecific signals. This finding provides evidence that specific probes can effectively identify single and double infections in DENV samples. PMID:24776933

  11. Establishment and preliminary application of Dengue virus envelope domain Ⅲ IgG antibody capture enzyme-linked immuno-absorbent assay

    Institute of Scientific and Technical Information of China (English)

    胡冬梅

    2013-01-01

    Objective To establish a highly sensitive and specific assay to detect Dengue virus(DENV) envelope protein domainⅢ(EDⅢ) IgG antibody,and to explore its value in the diagnosis and seroepidemiological survey of dengue

  12. Antiviral activity of four types of bioflavonoid against dengue virus type-2

    Directory of Open Access Journals (Sweden)

    Zandi Keivan

    2011-12-01

    Full Text Available Abstract Background Dengue is a major mosquito-borne disease currently with no effective antiviral or vaccine available. Effort to find antivirals for it has focused on bioflavonoids, a plant-derived polyphenolic compounds with many potential health benefits. In the present study, antiviral activity of four types of bioflavonoid against dengue virus type -2 (DENV-2 in Vero cell was evaluated. Anti-dengue activity of these compounds was determined at different stages of DENV-2 infection and replication cycle. DENV replication was measured by Foci Forming Unit Reduction Assay (FFURA and quantitative RT-PCR. Selectivity Index value (SI was determined as the ratio of cytotoxic concentration 50 (CC50 to inhibitory concentration 50 (IC50 for each compound. Results The half maximal inhibitory concentration (IC50 of quercetin against dengue virus was 35.7 μg mL-1 when it was used after virus adsorption to the cells. The IC50 decreased to 28.9 μg mL-1 when the cells were treated continuously for 5 h before virus infection and up to 4 days post-infection. The SI values for quercetin were 7.07 and 8.74 μg mL-1, respectively, the highest compared to all bioflavonoids studied. Naringin only exhibited anti-adsorption effects against DENV-2 with IC50 = 168.2 μg mL-1 and its related SI was 1.3. Daidzein showed a weak anti-dengue activity with IC50 = 142.6 μg mL-1 when the DENV-2 infected cells were treated after virus adsorption. The SI value for this compound was 1.03. Hesperetin did not exhibit any antiviral activity against DENV-2. The findings obtained from Foci Forming Unit Reduction Assay (FFURA were corroborated by findings of the qRT-PCR assays. Quercetin and daidzein (50 μg mL-1 reduced DENV-2 RNA levels by 67% and 25%, respectively. There was no significant inhibition of DENV-2 RNA levels with naringin and hesperetin. Conclusion Results from the study suggest that only quercetin demonstrated significant anti-DENV-2 inhibitory activities. Other

  13. Diagnosis of Dengue Infection Using Conventional and Biosensor Based Techniques

    Directory of Open Access Journals (Sweden)

    Om Parkash

    2015-10-01

    Full Text Available Dengue is an arthropod-borne viral disease caused by four antigenically different serotypes of dengue virus. This disease is considered as a major public health concern around the world. Currently, there is no licensed vaccine or antiviral drug available for the prevention and treatment of dengue disease. Moreover, clinical features of dengue are indistinguishable from other infectious diseases such as malaria, chikungunya, rickettsia and leptospira. Therefore, prompt and accurate laboratory diagnostic test is urgently required for disease confirmation and patient triage. The traditional diagnostic techniques for the dengue virus are viral detection in cell culture, serological testing, and RNA amplification using reverse transcriptase PCR. This paper discusses the conventional laboratory methods used for the diagnosis of dengue during the acute and convalescent phase and highlights the advantages and limitations of these routine laboratory tests. Subsequently, the biosensor based assays developed using various transducers for the detection of dengue are also reviewed.

  14. Identification of sequence motifs involved in Dengue virus-host interactions.

    Science.gov (United States)

    Asnet Mary, J; Paramasivan, R; Shenbagarathai, R

    2016-01-01

    Dengue fever is a rapidly spreading mosquito-borne virus infection, which remains a serious global public health problem. As there is no specific treatment or commercial vaccine available for effective control of the disease, the attempts on developing novel control strategies are underway. Viruses utilize the surface receptor proteins of host to enter into the cells. Though various proteins were said to be receptors of Dengue virus (DENV) using Virus Overlay Protein Binding Assay, the precise interaction between DENV and host is not explored. Understanding the structural features of domain III envelope glycoprotein would help in developing efficient antiviral inhibitors. Therefore, an attempt was made to identify the sequence motifs present in domain III envelope glycoprotein of Dengue virus. Computational analysis revealed that the NGR motif is present in the domain III envelope glycoprotein of DENV-1 and DENV-3. Similarly, DENV-1, DENV-2 and DENV-4 were found to contain Yxxphi motif which is a tyrosine-based sorting signal responsible for the interaction with a mu subunit of adaptor protein complex. High-throughput virtual screening resulted in five compounds as lead molecules based on glide score, which ranges from -4.664 to -6.52 kcal/Mol. This computational prediction provides an additional tool for understanding the virus-host interactions and helps to identify potential targets in the host. Further, experimental evidence is warranted to confirm the virus-host interactions and also inhibitory activity of reported lead compounds.

  15. Clinical outcome and genetic differences within a monophyletic Dengue virus type 2 population.

    Directory of Open Access Journals (Sweden)

    Hapuarachchige Chanditha Hapuarachchi

    Full Text Available The exact mechanisms of interplay between host and viral factors leading to severe dengue are yet to be fully understood. Even though previous studies have implicated specific genetic differences of Dengue virus (DENV in clinical severity and virus attenuation, similar studies with large-scale, whole genome screening of monophyletic virus populations are limited. Therefore, in the present study, we compared 89 whole genomes of DENV-2 cosmopolitan clade III isolates obtained from patients diagnosed with dengue fever (DF, n = 58, dengue hemorrhagic fever (DHF, n = 30 and dengue shock syndrome (DSS, n = 1 in Singapore between July 2010 and January 2013, in order to determine the correlation of observed viral genetic differences with clinical outcomes. Our findings showed no significant difference between the number of primary and secondary infections that progressed to DHF and DSS (p>0.05 in our study cohort. Despite being highly homogenous, study isolates possessed 39 amino acid substitutions of which 10 substitutions were fixed in three main groups of virus isolates. None of those substitutions were specifically associated with DHF and DSS. Notably, two evolutionarily unique virus groups possessing C-P43T+NS1-S103T+NS2A-V83I+NS3-R337K+ NS3-I600T+ NS5-P136S and NS2A-T119N mutations were exclusively found in patients with DF, the benign form of DENV infections. Those mutants were significantly associated with mild disease outcome. These observations indicated that disease progression into DHF and DSS within our patient population was more likely to be due to host than virus factors. We hypothesize that selection for potentially less virulent groups of DENV-2 in our study cohort may be an evolutionary adaptation of viral strains to extend their survival in the human-mosquito transmission cycle.

  16. Clinical outcome and genetic differences within a monophyletic Dengue virus type 2 population.

    Science.gov (United States)

    Hapuarachchi, Hapuarachchige Chanditha; Chua, Rachel Choon Rong; Shi, Yuan; Thein, Tun Lin; Lee, Linda Kay; Lee, Kim Sung; Lye, David Chien; Ng, Lee Ching; Leo, Yee Sin

    2015-01-01

    The exact mechanisms of interplay between host and viral factors leading to severe dengue are yet to be fully understood. Even though previous studies have implicated specific genetic differences of Dengue virus (DENV) in clinical severity and virus attenuation, similar studies with large-scale, whole genome screening of monophyletic virus populations are limited. Therefore, in the present study, we compared 89 whole genomes of DENV-2 cosmopolitan clade III isolates obtained from patients diagnosed with dengue fever (DF, n = 58), dengue hemorrhagic fever (DHF, n = 30) and dengue shock syndrome (DSS, n = 1) in Singapore between July 2010 and January 2013, in order to determine the correlation of observed viral genetic differences with clinical outcomes. Our findings showed no significant difference between the number of primary and secondary infections that progressed to DHF and DSS (p>0.05) in our study cohort. Despite being highly homogenous, study isolates possessed 39 amino acid substitutions of which 10 substitutions were fixed in three main groups of virus isolates. None of those substitutions were specifically associated with DHF and DSS. Notably, two evolutionarily unique virus groups possessing C-P43T+NS1-S103T+NS2A-V83I+NS3-R337K+ NS3-I600T+ NS5-P136S and NS2A-T119N mutations were exclusively found in patients with DF, the benign form of DENV infections. Those mutants were significantly associated with mild disease outcome. These observations indicated that disease progression into DHF and DSS within our patient population was more likely to be due to host than virus factors. We hypothesize that selection for potentially less virulent groups of DENV-2 in our study cohort may be an evolutionary adaptation of viral strains to extend their survival in the human-mosquito transmission cycle.

  17. Modulation of inflammation and pathology during dengue virus infection by p38 MAPK inhibitor SB203580.

    Science.gov (United States)

    Fu, Yilong; Yip, Andy; Seah, Peck Gee; Blasco, Francesca; Shi, Pei-Yong; Hervé, Maxime

    2014-10-01

    Dengue virus (DENV) infection could lead to dengue fever (DF), dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). The disease outcome is controlled by both viral and host factors. Inflammation mediators from DENV-infected cells could contribute to increased vascular permeability, leading to severe DHF/DSS. Therefore, suppression of inflammation could be a potential therapeutic approach for treatment of dengue patients. In this context, p38 MAPK (mitogen-activated protein kinase) is a key enzyme that modulates the initiation of stress and inflammatory responses. Here we show that SB203580, a p38 MAPK inhibitor, suppressed the over production of DENV-induced pro-inflammatory mediators such as TNF-α, IL-8, and RANTES from human PBMCs, monocytic THP-1, and granulocyte KU812 cell lines. Oral administration of SB203580 in DENV-infected AG129 mice prevented hematocrit rise and lymphopenia, limited the development of inflammation and pathology (including intestine leakage), and significantly improved survival. These results, for the first time, have provided experimental evidence to imply that a short term inhibition of p38 MAPK may be beneficial to reduce disease symptoms in dengue patients.

  18. Lineage shift of dengue virus in Eastern India: an increased implication for DHF/DSS.

    Science.gov (United States)

    Shrivastava, A; Soni, M; Shrivastava, S; Sharma, S; Dash, P K; Gopalan, N; Behera, P K; Parida, M M

    2015-06-01

    Dengue fever, a mosquito-borne viral disease, has become a major public health problem with marked expansion in recent decades. Dengue has now become hyperendemic in India with co-circulation of all the four serotypes. Herein, we report an unprecedented outbreak which occurred during August to October 2011 in Odisha, eastern India. This is the first report of a large epidemic in Odisha. Detailed serological and molecular investigation was carried out to identify the aetiology. Almost half of the samples were found to be dengue antigen (NS1) positive. Further molecular assays revealed circulation of mixed dengue serotypes (DENV-2 and DENV-3). Cosmopolitan genotype of DENV-2 and -3 were identified as the aetiology by phylogenetic analysis. Interestingly, a new lineage of DENV-3 within cosmopolitan genotype was incriminated in this outbreak. The emergence of the unprecedented magnitude of the dengue outbreak with the involvement of a novel lineage of DENV in a newer state of India is a major cause for concern. There is an urgent need to monitor phylodynamics of dengue viruses in other endemic areas.

  19. Primary dengue virus infections induce differential cytokine production in Mexican patients.

    Science.gov (United States)

    Cruz Hernández, Sergio Isaac de la; Puerta-Guardo, Henry Nelson; Flores Aguilar, Hilario; González Mateos, Silvia; López Martinez, Irma; Ortiz-Navarrete, Vianney; Ludert, Juan E; Angel, Rosa María del

    2016-03-01

    Severe dengue pathogenesis is not fully understood, but high levels of proinflammatory cytokines have been associated with dengue disease severity. In this study, the cytokine levels in 171 sera from Mexican patients with primary dengue fever (DF) and dengue haemorrhagic fever (DHF) from dengue virus (DENV) 1 (n = 116) or 2 (n = 55) were compared. DF and DHF were defined according to the patient's clinical condition, the primary infections as indicated by IgG enzymatic immunoassay negative results, and the infecting serotype as assessed by real-time reverse transcription-polymerase chain reaction. Samples were analysed for circulating levels of interleukin (IL)-12p70, interferon (IFN)-γ, tumour necrosis factor (TNF)-α, IL-6, and IL-8 using a commercial cytometric bead array. Significantly higher IFN-γ levels were found in patients with DHF than those with DF. However, significantly higher IL-12p70, TNF-α, and IL-6 levels were associated with DHF only in patients who were infected with DENV2 but not with DENV1. Moreover, patients with DF who were infected with DENV1 showed higher levels of IL-12p70, TNF-α, and IL-6 than patients with DHF early after-fever onset. The IL-8 levels were similar in all cases regardless of the clinical condition or infection serotype. These results suggest that the association between high proinflammatory cytokine levels and dengue disease severity does not always stand, and it once again highlights the complex nature of DHF pathogenesis.

  20. Underrecognized mildly symptomatic viremic dengue virus infections in rural Thai schools and villages

    NARCIS (Netherlands)

    Yoon, I.K.; Rothman, A.L.; Tannitisupawong, D.; Srikiatkhachorn, A.; Jarman, R.G.; Aldstadt, J.; Nisalak, A.; Mammen Jr., M.P.; Thammapalo, S.; Green, S.; Libraty, D.H.; Gibbons, R.V.; Getis, A.; Endy, T.; Jones, J.W.; Koenraadt, C.J.M.; Morrison, A.C.; Fansiri, T.; Pimgate, C.; Scott, T.W.

    2012-01-01

    BACKGROUND: The understanding of dengue virus (DENV) transmission dynamics and the clinical spectrum of infection are critical to informing surveillance and control measures. Geographic cluster studies can elucidate these features in greater detail than cohort studies alone. METHODS: A 4-year longit

  1. Dengue Virus Transmission by Blood Stem Cell Donor after Travel to Sri Lanka; Germany, 2013

    Centers for Disease Control (CDC) Podcasts

    2014-09-22

    Dr. Mike Miller reads an abridged version of the article, Dengue Virus Transmission by Blood Stem Cell Donor after Travel to Sri Lanka; Germany, 2013.  Created: 9/22/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 10/8/2014.

  2. Functional importance of dengue virus maturation : infectious properties of immature virions

    NARCIS (Netherlands)

    Zybert, Izabela A.; van der Ende-Metselaar, Heidi; Wilschut, Jan; Smit, Jolanda M.

    2008-01-01

    Prior to the release of flavivirus particles from infected cells, the viral surface protein prM is cleaved to M by the cellular enzyme furin. For dengue virus (DENV), this maturation process appears to be very inefficient since a high proportion of progeny virions contain uncleaved prM. Furthermore,

  3. Antibody-dependent enhancement of dengue virus infection is inhibited by SA-17, a doxorubicin derivative

    NARCIS (Netherlands)

    Ayala Nunez, Vanesa; Jarupathirun, Patsaporn; Kaptein, Suzanne; Neyts, Johan; Smit, Jolanda

    2013-01-01

    Antibody-dependent enhancement (ADE) is thought to play a critical role in the exacerbation of dengue virus (DENV)-induced disease during a heterologous re-infection. Despite ADE's clinical impact, only a few antiviral compounds have been assessed for their anti-ADE activity. We reported earlier tha

  4. Incidence and risk factors of probable dengue virus infection among Dutch travelers to Asia.

    NARCIS (Netherlands)

    F.G.J. Cobelens (Frank); J. Groen (Jan); A.D.M.E. Osterhaus (Albert); A. Leentvaar-Kuipers (Anne); P.E.M. Wertheim-van Dillen (Pauline); P.A. Kager (Piet)

    2002-01-01

    textabstractWe studied the incidence of dengue virus (DEN) infections in a cohort of Dutch short-term travellers to endemic areas in Asia during 1991-92. Sera were collected before and after travel. All post-travel sera were tested for DEN immunoglobulin M (IgM) [IgM capture (MAC)-enzyme-linked immu

  5. Recent advances and prospective researches on molecular epidemiology of dengue viruses

    Directory of Open Access Journals (Sweden)

    Vincent Deubel

    1992-01-01

    Full Text Available The determination of amino acid changes in the envelop protein by direct sequencing of either genomic RNA or PCR-amplified cDNA fragments provides useful informations for assessing the genetic variability and the geographic distribution of the actually most widespread dengue-2 serotype. The possible link of variations in the envelope protein-gene and virus virulence is discussed.

  6. How antibodies alter the cell entry pathway of dengue virus particles in macrophages

    NARCIS (Netherlands)

    Ayala-Nunez, Nilda V.; Hoornweg, Tabitha E.; van de Pol, Denise P. I.; Sjollema, Klaas A.; Flipse, Jacky; van der Schaar, Hilde M.; Smit, Jolanda M.

    2016-01-01

    Antibody-dependent enhancement of dengue virus (DENV) infection plays an important role in the exacerbation of DENV-induced disease. To understand how antibodies influence the fate of DENV particles, we explored the cell entry pathway of DENV in the absence and presence of antibodies in macrophage-l

  7. Dengue Virus Specific Immune Response: Implications for laboratory diagnosis and vaccine development

    NARCIS (Netherlands)

    P. Koraka (Penelope)

    2007-01-01

    textabstractDengue viruses (DENV 1-4) belong to the family Flaviviridae, genus Flavivirus. They are transmitted to humans through the bite of infected mosquitoes of the Aedes species. An estimated 100 million people are annually infected with DENV and over two billion people are at risk in acquiring

  8. Genetic relatedness of dengue viruses in Key West, Florida, USA, 2009-2010.

    Science.gov (United States)

    Muñoz-Jordán, Jorge L; Santiago, Gilberto A; Margolis, Harold; Stark, Lillian

    2013-04-01

    Sequencing of dengue virus type 1 (DENV-1) strains isolated in Key West/Monroe County, Florida, indicate endemic transmission for >2 years of a distinct and predominant sublineage of the American-African genotype. DENV-1 strains isolated elsewhere in Florida grouped within a separate Central American lineage. Findings indicate endemic transmission of DENV into the continental United States.

  9. Immunofluorescence assay method to detect dengue virus in Paniai-Papua

    Science.gov (United States)

    Sucipto, Teguh Hari; Ahwanah, Nur Laila Fitriati; Churrotin, Siti; Matake, Norifumi; Kotaki, Tomohiro; Soegijanto, Soegeng

    2016-03-01

    The dengue viruses (DENV), which include in the family Flaviviridae and the genus Flavivirus, was endemic in tropical areas and had been transmitted to humans by Aedes aegypti. An increasing number of immigrants from endemic areas to the non-endemic areas have emphasized the need for a simple and reliable test for the diagnosis of dengue virus infection. The purpose of this study was to detect the dengue virus by immunofluorescence assay (IFA) in the general population at Paniai-Papua. The results obtained from this study had showed a significantly better discrimination for DENV specific IgG antibodies. A total of 158 samples, 116 samples were IgG antibodies positive and 42 samples were negative. The conclusion of this study, Papua is not only a malaria endemic area, but also dengue virus infections were detected by IFA method. Therefore, the IFA can be used as an important diagnostic tool, which is a quick and an easy way to test samples from immigrants who come to the non-endemic areas.

  10. Chikungunya Virus Infections Among Patients with Dengue-Like Illness at a Tertiary Care Hospital in the Philippines, 2012-2013.

    Science.gov (United States)

    Velasco, John Mark; Valderama, Maria Theresa; Lopez, Maria Nila; Chua, Domingo; Latog, Rene; Roque, Vito; Corpuz, June; Klungthong, Chonticha; Rodpradit, Prinyada; Hussem, Kittinun; Poolpanichupatam, Yongyuth; Macareo, Louis; Fernandez, Stefan; Yoon, In-Kyu

    2015-12-01

    Chikungunya virus (CHIKV) often co-circulates with dengue virus (DENV). A cross-sectional surveillance study was conducted at a tertiary hospital in Manila, Philippines, to describe the prevalence and characteristics of DENV and CHIKV infections among patients seeking care for dengue-like illness. Acute blood samples from patients ≥ 6 months of age clinically diagnosed with dengue from November 2012 to December 2013 underwent reverse transcription polymerase chain reaction (RT-PCR) to detect DENV and CHIKV RNA. A total of 118 patients with clinically diagnosed dengue (age range = 1-89 years, mean = 22 years; male-to-female ratio = 1.51) were tested by DENV RT-PCR; 40 (34%) were DENV PCR-positive (age range = 1-45 years, mean = 17 years). All DENV serotypes were detected: 11 (28%) DENV-1, 6 (15%) DENV-2, 6 (15%) DENV-3, and 17 (42%) DENV-4. Of 112 patients clinically diagnosed with dengue and tested by CHIKV RT-PCR, 11 (10%) were CHIKV PCR-positive (age range = 2-47 years, mean = 20.3 years). No coinfections were detected. Presenting signs/symptoms did not differ between DENV- and CHIKV-positive cases. Sequencing of envelope 1 gene from two CHIKV PCR-positive samples showed Asian genotype. This study highlights the potential for misdiagnosis of medically attended CHIKV infections as DENV infection and the difficulty in clinically differentiating dengue and chikungunya based on presenting signs/symptoms alone. This underscores the necessity for diagnostic laboratory tests to distinguish CHIKV infections in the background of actively co-circulating DENV.

  11. Simulated Transmission of the Dengue Virus Across the US-Mexico Border Using Remotely Sensed and Ground Based Weather Data

    Science.gov (United States)

    Morin, Cory; Quattrochi, Dale A.

    2015-01-01

    Incidence of dengue fever, caused by a mosquito transmitted virus, have increased in the Americas during recent decades. In the US, local transmission has been reported in southern Texas and Florida. However, despite its close proximity to dengue endemic areas in Mexico and the presence of a primary mosquito vector, there are no reports of local transmission in Arizona. Many studies have demonstrated that weather influences dengue virus transmission by regulating vector development rates, vector habitat availability, and the duration of the virus extrinsic incubation period (EIP). The EIP, the period between mosquito infection and the ability for it to retransmit the virus, is especially important given its high sensitivity to temperature and the short lifespan of mosquitoes. Other studies, however, have suggested that human related factors such as socioeconomic status and herd immunity may explain much of the disparity in dengue incidence in the US-Mexico border region. Using a meteorologically driven model of vector population dynamics and virus transmission we compare simulations of dengue fever cases in southern Arizona and northern Mexico. A Monte Carlo approach is employed to select parameter values by evaluating simulations in Hermosillo Mexico with reported dengue fever case data. Simulations that replicate the case data best are retained and rerun using remotely sensed climate data from other Arizona and Mexico locations to determine the relative influence of weather on virus transmission. Although human and environmental factors undoubtedly influence dengue transmission in the US-Mexico border regions, weather is a major facilitator of the transmission process.

  12. Seroprevalence of antibodies against dengue virus among pregnant women in the Democratic Republic of Sao Tome and Principe.

    Science.gov (United States)

    Yen, Tsai-Ying; Trovoada dos Santos, Maria de Jesus; Tseng, Lien-Feng; Chang, Shu-Feng; Cheng, Chien-Fu; Carvalho, Arlindo Vicente de Assunção; Shu, Pei-Yun; Lien, Jih-Ching; Tsai, Kun-Hsien

    2016-03-01

    Dengue fever has become a worldwide public health concern, threatening an estimated 40% of the world's population. However, most resources and attention are still focused on malaria, while dengue statuses are poorly recognized in many African countries. In this serological survey, dengue virus (DENV) transmission was demonstrated by using serum samples collected from 78 pregnant women in the Democratic Republic of Sao Tome and Principe (DRSTP) during 2003 to 2004. Immunofluorescence assay was performed and 31 samples (39.74%) were found positive for DENV antibodies. Indirect enzyme-linked immunosorbent assay (ELISA) showed that 53 samples (67.95%) were positive for dengue E IgG, and 38 samples (48.72%) were positive for NS1 IgG. A prevalence of 35.90% was therefore determined for dengue IgG by considering samples that yielded positive results by all three tests. Cross-reactions with other flaviviruses were examined by indirect ELISA against Japanese encephalitis virus, West Nile virus, and yellow fever virus. Only one sample exhibited stronger absorbance against Japanese encephalitis virus and West Nile virus. Moreover, one sample was positive for dengue IgM. These results agreed with the previous researches in neighboring countries and suggested DENV exposure. The study contributes to raising public awareness of dengue and supporting future control strategies.

  13. Dengue-induced autophagy, virus replication and protection from cell death require ER stress (PERK) pathway activation.

    Science.gov (United States)

    Datan, E; Roy, S G; Germain, G; Zali, N; McLean, J E; Golshan, G; Harbajan, S; Lockshin, R A; Zakeri, Z

    2016-03-03

    A virus that reproduces in a host without killing cells can easily establish a successful infection. Previously, we showed that dengue-2, a virus that threatens 40% of the world, induces autophagy, enabling dengue to reproduce in cells without triggering cell death. Autophagy further protects the virus-laden cells from further insults. In this study, we evaluate how it does so; we show that dengue upregulates host pathways that increase autophagy, namely endoplasmic reticulum (ER) stress and ataxia telangiectasia mutated (ATM) signaling followed by production of reactive oxygen species (ROS). Inhibition of ER stress or ATM signaling abrogates the dengue-conferred protection against other cell stressors. Direct inhibition of ER stress response in infected cells decreases autophagosome turnover, reduces ROS production and limits reproduction of dengue virus. Blocking ATM activation, which is an early response to infection, decreases transcription of ER stress response proteins, but ATM has limited impact on production of ROS and virus titers. Production of ROS determines only late-onset autophagy in infected cells and is not necessary for dengue-induced protection from stressors. Collectively, these results demonstrate that among the multiple autophagy-inducing pathways during infection, ER stress signaling is more important to viral replication and protection of cells than either ATM or ROS-mediated signaling. To limit virus production and survival of dengue-infected cells, one must address the earliest phase of autophagy, induced by ER stress.

  14. Two different dengue virus strains in the Japanese epidemics of 2014.

    Science.gov (United States)

    Nakayama, Eri; Kotaki, Akira; Tajima, Shigeru; Kawada, Miki; Miura, Kuniharu; Gemma, Aki; Adachi, Takuya; Sekizuka, Tsuyoshi; Kato, Kengo; Yamashita, Akifumi; Moi, Meng Ling; Ikeda, Makiko; Yagasaki, Kazumi; Shibasaki, Kenichi; Saijo, Masayuki; Kuroda, Makoto; Takasaki, Tomohiko

    2016-10-01

    In late August 2014, dengue cases were reported in Japan, and a total of 162 cases were confirmed. In the present study, the envelope (E) gene sequences of 12 specimens from the dengue patients were determined. A dengue virus serotype 1 (DENV1) strain (D1/Hu/Shizuoka/NIID181/2014), which was clearly different from the first reported strain (D1/Hu/Saitama/NIID100/2014), was identified, although the other 11 specimens showed the same nucleotide sequences as D1/Hu/Saitama/NIID100/2014. The E gene sequences of two different strains were compared with those of nine DENV1 strains of imported cases in Japan in 2014. Phylogenetic analysis based on the E gene sequences showed that the D1/Hu/Saitama/NIID100/2014 strain was closely related to a strain isolated from an imported case from Singapore. Although no strain closely related to D1/Hu/Shizuoka/NIID181/2014 was found in these imported strains, the strain was closely related to isolates in Thailand and Taiwan in 2009. These data indicate that the dengue cases in Japan were caused by two different dengue virus strains that entered Japan through different means.

  15. Cissampelos pareira Linn: Natural Source of Potent Antiviral Activity against All Four Dengue Virus Serotypes.

    Directory of Open Access Journals (Sweden)

    Ruchi Sood

    2015-12-01

    Full Text Available Dengue, a mosquito-borne viral disease, poses a significant global public health risk. In tropical countries such as India where periodic dengue outbreaks can be correlated to the high prevalence of the mosquito vector, circulation of all four dengue viruses (DENVs and the high population density, a drug for dengue is being increasingly recognized as an unmet public health need.Using the knowledge of traditional Indian medicine, Ayurveda, we developed a systematic bioassay-guided screening approach to explore the indigenous herbal bio-resource to identify plants with pan-DENV inhibitory activity. Our results show that the alcoholic extract of Cissampelos pariera Linn (Cipa extract was a potent inhibitor of all four DENVs in cell-based assays, assessed in terms of viral NS1 antigen secretion using ELISA, as well as viral replication, based on plaque assays. Virus yield reduction assays showed that Cipa extract could decrease viral titers by an order of magnitude. The extract conferred statistically significant protection against DENV infection using the AG129 mouse model. A preliminary evaluation of the clinical relevance of Cipa extract showed that it had no adverse effects on platelet counts and RBC viability. In addition to inherent antipyretic activity in Wistar rats, it possessed the ability to down-regulate the production of TNF-α, a cytokine implicated in severe dengue disease. Importantly, it showed no evidence of toxicity in Wistar rats, when administered at doses as high as 2g/Kg body weight for up to 1 week.Our findings above, taken in the context of the human safety of Cipa, based on its use in Indian traditional medicine, warrant further work to explore Cipa as a source for the development of an inexpensive herbal formulation for dengue therapy. This may be of practical relevance to a dengue-endemic resource-poor country such as India.

  16. The cellular immune response plays an important role in protecting against dengue virus in the mouse encephalitis model.

    Science.gov (United States)

    Gil, Lázaro; López, Carlos; Blanco, Aracelys; Lazo, Laura; Martín, Jorge; Valdés, Iris; Romero, Yaremis; Figueroa, Yassel; Guillén, Gerardo; Hermida, Lisset

    2009-02-01

    For several years, researchers have known that the generation of neutralizing antibodies is a prerequisite for attaining adequate protection against dengue virus. Nevertheless, the cellular immune response is the principal arm of the adaptive immune system against non-cytopathic viruses such as dengue, as once the virus enters into the cell it is necessary to destroy it to eliminate the virus. To define the role of the cellular immune response in the protection against dengue, we selected the mouse encephalitis model. Mice were immunized with a single dose of infective dengue 2 virus and different markers of both branches of the induced adaptive immunity were measured. Animals elicited a broad antibody response against the four dengue virus serotypes, but neutralizing activity was only detected against the homologous serotype. On the other hand, the splenocytes of the infected animals strongly proliferated after in vitro stimulation with the homologous virus, and specifically the CD8 T-cell subset was responsible for the secretion of the cytokine IFN-gamma. Finally, to define the role of T cells in in vivo protection, groups of animals were inoculated with the depleting monoclonal antibodies anti-CD4 or anti-CD8. Only depletion with anti-CD8 decreased to 50% the level of protection reached in the non-depleted mice. The present work constitutes the first report defining the role of the cellular immune response in protection against dengue virus in the mouse model.

  17. Elevated plasma levels of the long pentraxin, pentraxin 3, in severe dengue virus infections.

    NARCIS (Netherlands)

    Mairuhu, A.T.; Peri, G.; Setiati, T.E.; Hack, C.E.; Koraka, P.; Soemantri, A.; Osterhaus, A.D.M.E.; Brandjes, D.P.; Meer, J.W.M. van der; Mantovani, A.; Gorp, E. van

    2005-01-01

    C-reactive protein is one of the most widely used indicators of the response of acute-phase proteins. The measurement of C-reactive protein in dengue, however, is clinically not useful, because of marginally elevated levels and absent association with disease severity. The prototypic long pentraxin,

  18. Elevated plasma levels of the long pentraxin, pentraxin 3, in severe dengue virus infections

    NARCIS (Netherlands)

    Mairuhu, ATA; Peri, G; Setiati, TE; Hack, CE; Koraka, P; Soemantri, A; Osterhaus, ADME; Brandjes, DPM; van der Meer, JWM; Mantovani, A; van Gorp, ECM

    2005-01-01

    C-reactive protein is one of the most widely used indicators of the response of acute-phase proteins. The measurement of C-reactive protein in dengue, however, is clinically not useful, because of marginally elevated levels and absent association with disease severity. The prototypic long pentraxin,

  19. An exhaustive study of mutation process in 139 sequences of dengue virus

    Science.gov (United States)

    Arroyo Duarte, R. S.; Chumakov, S.

    2012-10-01

    We perform an analysis of entropies of n-mer distributions (n = 1,2, ..., 10) in 139 genomes of dengue virus of all serotypes. We propose a mutation model for these viruses. Due to the fact that virus mutations must preserve some information that characterizes the pathogen, entropies Hn of n-mer distributions must have some inequalities, so that the mutations of these genomes don't result in loss of information which characterizes the virus. This work focuses on the analysis of n-mer frequency distribution entropies, allowing to establish numeric limits, identifying the point until which a spontaneous mutation becomes a random genome.

  20. Dendritic cells in dengue virus infection: Targets of virus replication and mediators of immunity

    Directory of Open Access Journals (Sweden)

    Michael A. Schmid

    2014-12-01

    Full Text Available Dendritic cells (DCs are sentinels of the immune system and detect pathogens at sites of entry, such as the skin. In addition to the ability of DCs to control infections directly via their innate immune functions, DCs help to prime adaptive B and T cell responses via antigen presentation in lymphoid tissues. Infected Aedes aegypti or Ae. albopictus mosquitoes transmit the four dengue virus (DENV serotypes to humans while probing for small blood vessels in the skin. DENV causes the most prevalent arthropod-borne viral disease in humans, yet no vaccine or specific therapeutic is currently approved. Although primary DENV infection confers life-long protective immunity against re-infection with the same DENV serotype, secondary infection with a different DENV serotype can lead to increased disease severity via cross-reactive T cells or enhancing antibodies. This review summarizes recent findings in humans and animal models about DENV infection of DCs, monocytes and macrophages. We discuss the dual role of DCs as both targets of DENV replication and mediators of innate and adaptive immunity, and summarize immune evasion strategies whereby DENV impairs the function of infected DCs. We suggest that DCs play a key role in priming DENV-specific neutralizing or potentially harmful memory B and T cell responses, and that future DC-directed therapies may help induce protective memory responses and reduce dengue pathogenesis.

  1. Comparative sensitivity of three mosquito cell lines for isolation of dengue viruses.

    Science.gov (United States)

    Kuno, G; Gubler, D J; Vélez, M; Oliver, A

    1985-01-01

    Comparative studies were carried out on three mosquito cell lines (C6/36 clone of Aedes albopictus, AP-61 from A. pseudoscutellaris, and TRA-284 from Toxorhynchites amboinensis) to determine their sensitivity to dengue virus isolation, growth, and handling characteristics for immunofluorescent testing. Virus isolation rates from human sera were the highest in the TRA-284-SF (a line adapted to serum-free medium), followed by the TRA-284 parental line and AP-61. Virus isolation was the lowest in the C6/36 line. All 3 cell lines were comparable in terms of ease of handling, but C6/36 cells were preferable for detecting infected cells by the direct fluorescent antibody test (DFAT) because of frequent cell clumping in the AP-61 and TRA-284 lines. Early detection of viral antigen of all 4 serotypes in the infected cells by DFAT was dependent upon the virus titre in the serum. The AP-61 and TRA-284-SF cells were the best for early detection and identification of viral antigen. Similarly, both AP-61 and TRA-284 cells were more resistant than C6/36 cells to toxic effects of human sera. Based on the economy of using the serum-free medium, their higher sensitivity for dengue virus isolation, and their ease of handling, it is recommended that the TRA-284-SF cell line be used for routine dengue virus isolation in laboratories with cell culture capability.

  2. Comparative sensitivity of three mosquito cell lines for isolation of dengue viruses*

    Science.gov (United States)

    Kuno, G.; Gubler, D. J.; Vélez, M.; Oliver, A.

    1985-01-01

    Comparative studies were carried out on three mosquito cell lines (C6/36 clone of Aedes albopictus, AP-61 from A. pseudoscutellaris, and TRA-284 from Toxorhynchites amboinensis) to determine their sensitivity to dengue virus isolation, growth, and handling characteristics for immunofluorescent testing. Virus isolation rates from human sera were the highest in the TRA-284-SF (a line adapted to serum-free medium), followed by the TRA-284 parental line and AP-61. Virus isolation was the lowest in the C6/36 line. All 3 cell lines were comparable in terms of ease of handling, but C6/36 cells were preferable for detecting infected cells by the direct fluorescent antibody test (DFAT) because of frequent cell clumping in the AP-61 and TRA-284 lines. Early detection of viral antigen of all 4 serotypes in the infected cells by DFAT was dependent upon the virus titre in the serum. The AP-61 and TRA-284-SF cells were the best for early detection and identification of viral antigen. Similarly, both AP-61 and TRA-284 cells were more resistant than C6/36 cells to toxic effects of human sera. Based on the economy of using the serum-free medium, their higher sensitivity for dengue virus isolation, and their ease of handling, it is recommended that the TRA-284-SF cell line be used for routine dengue virus isolation in laboratories with cell culture capability. PMID:2861916

  3. Consequences of the expanding global distribution of Aedes albopictus for dengue virus transmission.

    Directory of Open Access Journals (Sweden)

    Louis Lambrechts

    Full Text Available The dramatic global expansion of Aedes albopictus in the last three decades has increased public health concern because it is a potential vector of numerous arthropod-borne viruses (arboviruses, including the most prevalent arboviral pathogen of humans, dengue virus (DENV. Ae. aegypti is considered the primary DENV vector and has repeatedly been incriminated as a driving force in dengue's worldwide emergence. What remains unresolved is the extent to which Ae. albopictus contributes to DENV transmission and whether an improved understanding of its vector status would enhance dengue surveillance and prevention. To assess the relative public health importance of Ae. albopictus for dengue, we carried out two complementary analyses. We reviewed its role in past dengue epidemics and compared its DENV vector competence with that of Ae. aegypti. Observations from "natural experiments" indicate that, despite seemingly favorable conditions, places where Ae. albopictus predominates over Ae. aegypti have never experienced a typical explosive dengue epidemic with severe cases of the disease. Results from a meta-analysis of experimental laboratory studies reveal that although Ae. albopictus is overall more susceptible to DENV midgut infection, rates of virus dissemination from the midgut to other tissues are significantly lower in Ae. albopictus than in Ae. aegypti. For both indices of vector competence, a few generations of mosquito colonization appear to result in a relative increase of Ae. albopictus susceptibility, which may have been a confounding factor in the literature. Our results lead to the conclusion that Ae. albopictus plays a relatively minor role compared to Ae. aegypti in DENV transmission, at least in part due to differences in host preferences and reduced vector competence. Recent examples of rapid arboviral adaptation to alternative mosquito vectors, however, call for cautious extrapolation of our conclusion. Vector status is a dynamic

  4. Single Assay Detection of Acute Bee Paralysis Virus, Kashmir Bee Virus and Israeli Acute Paralysis Virus

    DEFF Research Database (Denmark)

    Francis, Roy Mathew; Kryger, Per

    2012-01-01

    A new RT-PCR primer pair designed to identify Acute Bee Paralysis Virus (ABPV), Kashmir Bee Virus (KBV) or Israeli Acute Bee Paralysis Virus (IAPV) of honey bees (Apis mellifera L.) in a single assay is described. These primers are used to screen samples for ABPV, KBV, or IAPV in a single RT-PCR ......-PCR reaction saving time and money. The primers are located in the predicted overlapping gene (pog/ORFX) which is highly conserved across ABPV, KBV, IAPV and other dicistroviruses of social insects. This study has also identified the first case of IAPV in Denmark....

  5. Susceptibility of Aedes flavopictus miyarai and Aedes galloisi mosquito species in Japan to dengue type 2 virus

    Institute of Scientific and Technical Information of China (English)

    Raweewan Srisawat; Thipruethai Phanitchat; Narumon Komalamisra; Naoki Tamori; Lucky Runtuwene; Kaori Noguchi; Kyoko Hayashida; Shinya Hidano; Naganori Kamiyama; Ikuo Takashima; Tomohiko Takasaki; Ichiro Kurae; Narihiro Narita; Takashi Kobayashi; Yuki Eshita

    2016-01-01

    Objective: To evaluate the potential of local mosquitoes to act as vectors for dengue transmission in Japan.Methods: Serotype 2 Th NH28/93 was used to test the dengue susceptibility profiles of Aedes flavopictus miyarai(Ae. f. miyarai), Aedes galloisi(Ae. galloisi) and Aedes albopictus(Ae.albopictus), which were collected in Japan. We used Aedes aegypti from Thailand as a positive control. The mosquitoes were infected with the virus intrathoracically or orally. At 10 or 14 days post infection, the mosquitoes were dissected and total RNA was extracted from their abdomens, thoraxes, heads and legs. Mosquito susceptibility to dengue virus was evaluated using RT-PCR with dengue virus-specific primers. Differences in the infection and mortality rates of the different mosquito species were tested using Fisher’s exact probability test.Results: The infection rates for dengue virus administered intrathoracically to Ae. f. miyarai,Ae. galloisi and Aedes aegypti mosquitoes were identical by RT-PCR on Day 10 post infection.All of the body parts we tested were RT-PCR-positive for dengue virus. For the orally administered virus, the infection rates in the different body parts of the Ae. f. miyarai mosquitoes were slightly higher than those of Ae. albopictus mosquitoes, but were similar to the control mosquitoes(P > 0.05). The mortality rates for Ae. f. miyarai and Ae. albopictus mosquitoes were similar(P = 0.19). Our data indicated that dengue virus was able to replicate and disseminate to secondary infection sites in all of the four mosquito species(Japanese and Thai).Conclusions: Ae. albopictus is a well-known candidate for dengue transmission in Japan. However, our data suggest that Ae. f. miyarai from Ishigaki Island(near Okinawa Island) and Ae. galloisi from Hokkaido(Northern Japan) should also be regarded as potential vectors for dengue transmission in these regions. Further studies on these mosquitoes should be conducted.

  6. Susceptibility of Aedes flavopictus miyarai and Aedes galloisi mosquito species in Japan to dengue type 2 virus

    Institute of Scientific and Technical Information of China (English)

    Raweewan Srisawat; Ikuo Takashima; Tomohiko Takasaki; Ichiro Kurae; Narihiro Narita; Takashi Kobayashi; Yuki Eshita; Thipruethai Phanitchat; Narumon Komalamisra; Naoki Tamori; Lucky Runtuwene; Kaori Noguchi; Kyoko Hayashida; Shinya Hidano; Naganori Kamiyama

    2016-01-01

    Objective: To evaluate the potential of local mosquitoes to act as vectors for dengue transmission in Japan. Methods: Serotype 2 ThNH28/93 was used to test the dengue susceptibility profiles of Aedes flavopictus miyarai (Ae. f. miyarai), Aedes galloisi (Ae. galloisi) and Aedes albopictus (Ae. albopictus), which were collected in Japan. We used Aedes aegypti from Thailand as a positive control. The mosquitoes were infected with the virus intrathoracically or orally. At 10 or 14 days post infection, the mosquitoes were dissected and total RNA was extracted from their abdomens, thoraxes, heads and legs. Mosquito susceptibility to dengue virus was evaluated using RT-PCR with dengue virus-specific primers. Differences in the infection and mortality rates of the different mosquito species were tested using Fisher's exact probability test. Results: The infection rates for dengue virus administered intrathoracically to Ae. f. miyarai, Ae. galloisi and Aedes aegypti mosquitoes were identical by RT-PCR on Day 10 post infection. All of the body parts we tested were RT-PCR-positive for dengue virus. For the orally admin-istered virus, the infection rates in the different body parts of the Ae. f. miyarai mosquitoes were slightly higher than those of Ae. albopictus mosquitoes, but were similar to the control mosquitoes (P>0.05). The mortality rates for Ae. f. miyarai and Ae. albopictus mosquitoes were similar (P=0.19). Our data indicated that dengue virus was able to replicate and disseminate to secondary infection sites in all of the four mosquito species (Japanese and Thai). Conclusions: Ae. albopictus is a well-known candidate for dengue transmission in Japan. However, our data suggest that Ae. f. miyarai from Ishigaki Island (near Okinawa Island) and Ae. galloisi from Hokkaido (Northern Japan) should also be regarded as potential vectors for dengue transmission in these regions. Further studies on these mosquitoes should be conducted.

  7. Phospholipase A2 isolated from the venom of Crotalus durissus terrificus inactivates dengue virus and other enveloped viruses by disrupting the viral envelope.

    Directory of Open Access Journals (Sweden)

    Vanessa Danielle Muller

    Full Text Available The Flaviviridae family includes several virus pathogens associated with human diseases worldwide. Within this family, Dengue virus is the most serious threat to public health, especially in tropical and sub-tropical regions of the world. Currently, there are no vaccines or specific antiviral drugs against Dengue virus or against most of the viruses of this family. Therefore, the development of vaccines and the discovery of therapeutic compounds against the medically most important flaviviruses remain a global public health priority. We previously showed that phospholipase A2 isolated from the venom of Crotalus durissus terrificus was able to inhibit Dengue virus and Yellow fever virus infection in Vero cells. Here, we present evidence that phospholipase A2 has a direct effect on Dengue virus particles, inducing a partial exposure of genomic RNA, which strongly suggests inhibition via the cleavage of glycerophospholipids at the virus lipid bilayer envelope. This cleavage might induce a disruption of the lipid bilayer that causes a destabilization of the E proteins on the virus surface, resulting in inactivation. We show by computational analysis that phospholipase A2 might gain access to the Dengue virus lipid bilayer through the pores found on each of the twenty 3-fold vertices of the E protein shell on the virus surface. In addition, phospholipase A2 is able to inactivate other enveloped viruses, highlighting its potential as a natural product lead for developing broad-spectrum antiviral drugs.

  8. Phospholipase A2 isolated from the venom of Crotalus durissus terrificus inactivates dengue virus and other enveloped viruses by disrupting the viral envelope.

    Science.gov (United States)

    Muller, Vanessa Danielle; Soares, Ricardo Oliveira; dos Santos, Nilton Nascimento; Trabuco, Amanda Cristina; Cintra, Adelia Cristina; Figueiredo, Luiz Tadeu; Caliri, Antonio; Sampaio, Suely Vilela; Aquino, Victor Hugo

    2014-01-01

    The Flaviviridae family includes several virus pathogens associated with human diseases worldwide. Within this family, Dengue virus is the most serious threat to public health, especially in tropical and sub-tropical regions of the world. Currently, there are no vaccines or specific antiviral drugs against Dengue virus or against most of the viruses of this family. Therefore, the development of vaccines and the discovery of therapeutic compounds against the medically most important flaviviruses remain a global public health priority. We previously showed that phospholipase A2 isolated from the venom of Crotalus durissus terrificus was able to inhibit Dengue virus and Yellow fever virus infection in Vero cells. Here, we present evidence that phospholipase A2 has a direct effect on Dengue virus particles, inducing a partial exposure of genomic RNA, which strongly suggests inhibition via the cleavage of glycerophospholipids at the virus lipid bilayer envelope. This cleavage might induce a disruption of the lipid bilayer that causes a destabilization of the E proteins on the virus surface, resulting in inactivation. We show by computational analysis that phospholipase A2 might gain access to the Dengue virus lipid bilayer through the pores found on each of the twenty 3-fold vertices of the E protein shell on the virus surface. In addition, phospholipase A2 is able to inactivate other enveloped viruses, highlighting its potential as a natural product lead for developing broad-spectrum antiviral drugs.

  9. Epstein-Barr virus co-infection in a patient with dengue fever presenting with post-infectious cerebellitis: a case report

    Directory of Open Access Journals (Sweden)

    Karunarathne Suneth

    2012-01-01

    Full Text Available Abstract Introduction Post-infectious cerebellitis is an acute form of inflammatory encephalitis mainly limited to the cerebellum. It is commonly found in children, especially after viral infections such as Epstein-Barr virus. Post-infectious cerebellitis presents with acute onset dysarthria and ataxia. To the best of our knowledge, this is the first case report of post-infectious cerebellitis in a patient with both dengue and Epstein-Barr viral infection confirmed on serology. Case presentation A 43-year-old Sri Lankan Sinhala man presented with an acute febrile illness associated with thrombocytopenia. While being managed as uncomplicated dengue fever, our patient developed dysarthria, ataxia and cerebellar signs. Our patient's infectious disease screen was positive for both dengue and Epstein-Barr specific immunoglobulin M. A cerebrospinal fluid analysis was suggestive of viral meningoencephalitis while cerebrospinal fluid serology was positive for dengue immunoglobulin G. T2-weighted magnetic resonance images were consistent with post-viral cerebellitis. The patient was given full supportive care and he made an uneventful complete recovery. Conclusion There have been no previously reported cases of post-infectious cerebellitis associated with both Epstein-Barr and dengue viral infections confirmed by serology. Our patient's clinical features and findings on the imaging studies were consistent with post-viral cerebellitis. This report highlights the need to screen for other possible more common etiologies of a particular presentation before coming to a specific diagnosis based on initial findings. Uncomplicated cases of cerebellitis can be successfully managed with appropriate supportive measures with good prognosis, as in this case.

  10. Limited dengue virus replication in field-collected Aedes aegypti mosquitoes infected with Wolbachia.

    Directory of Open Access Journals (Sweden)

    Francesca D Frentiu

    2014-02-01

    Full Text Available INTRODUCTION: Dengue is one of the most widespread mosquito-borne diseases in the world. The causative agent, dengue virus (DENV, is primarily transmitted by the mosquito Aedes aegypti, a species that has proved difficult to control using conventional methods. The discovery that A. aegypti transinfected with the wMel strain of Wolbachia showed limited DENV replication led to trial field releases of these mosquitoes in Cairns, Australia as a biocontrol strategy for the virus. METHODOLOGY/PRINCIPAL FINDINGS: Field collected wMel mosquitoes that were challenged with three DENV serotypes displayed limited rates of body infection, viral replication and dissemination to the head compared to uninfected controls. Rates of dengue infection, replication and dissemination in field wMel mosquitoes were similar to those observed in the original transinfected wMel line that had been maintained in the laboratory. We found that wMel was distributed in similar body tissues in field mosquitoes as in laboratory ones, but, at seven days following blood-feeding, wMel densities increased to a greater extent in field mosquitoes. CONCLUSIONS/SIGNIFICANCE: Our results indicate that virus-blocking is likely to persist in Wolbachia-infected mosquitoes after their release and establishment in wild populations, suggesting that Wolbachia biocontrol may be a successful strategy for reducing dengue transmission in the field.

  11. Development of viable TAP-tagged dengue virus for investigation of host-virus interactions in viral replication.

    Science.gov (United States)

    Poyomtip, Teera; Hodge, Kenneth; Matangkasombut, Ponpan; Sakuntabhai, Anavaj; Pisitkun, Trairak; Jirawatnotai, Siwanon; Chimnaronk, Sarin

    2016-03-01

    Dengue virus (DENV) is a mosquito-borne flavivirus responsible for life-threatening dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS). The viral replication machinery containing the core non-structural protein 5 (NS5) is implicated in severe dengue symptoms but molecular details remain obscure. To date, studies seeking to catalogue and characterize interaction networks between viral NS5 and host proteins have been limited to the yeast two-hybrid system, computational prediction and co-immunoprecipitation (IP) of ectopically expressed NS5. However, these traditional approaches do not reproduce a natural course of infection in which a number of DENV NS proteins colocalize and tightly associate during the replication process. Here, we demonstrate the development of a recombinant DENV that harbours a TAP tag in NS5 to study host-virus interactions in vivo. We show that our engineered DENV was infective in several human cell lines and that the tags were stable over multiple viral passages, suggesting negligible structural and functional disturbance of NS5. We further provide proof-of-concept for the use of rationally tagged virus by revealing a high confidence NS5 interaction network in human hepatic cells. Our analysis uncovered previously unrecognized hnRNP complexes and several low-abundance fatty acid metabolism genes, which have been implicated in the viral life cycle. This study sets a new standard for investigation of host-flavivirus interactions.

  12. Screening of antiviral activities in medicinal plants extracts against dengue virus using dengue NS2B-NS3 protease assay.

    Science.gov (United States)

    Rothan, H A; Zulqarnain, M; Ammar, Y A; Tan, E C; Rahman, N A; Yusof, R

    2014-06-01

    Dengue virus infects millions of people worldwide and there is no vaccine or anti-dengue therapeutic available. Screening large numbers of medicinal plants for anti-dengue activities is an alternative strategy in order to find the potent therapeutic compounds. Therefore, this study was designed to identify anti-dengue activities in nineteen medicinal plant extracts that are used in traditional medicine. Local medicinal plants Vernonia cinerea, Hemigraphis reptans, Hedyotis auricularia, Laurentia longiflora, Tridax procumbers and Senna angustifolia were used in this study. The highest inhibitory activates against dengue NS2B-NS3pro was observed in ethanolic extract of S. angustifolia leaves, methanolic extract of V. cinerea leaves and ethanol extract of T. procumbens stems. These findings were further verified by in vitro viral inhibition assay. Methanolic extract of V. cinerea leaves, ethanol extract of T. procumbens stems and at less extent ethanolic extract of S. angustifolia leaves were able to maintain the normal morphology of DENV2-infected Vero cells without causing much cytopathic effects (CPE). The percentage of viral inhibition of V. cinerea and T. procumbens extracts were significantly higher than S. angustifolia extract as measured by plaque formation assay and RT-qPCR. In conclusion, The outcome of this study showed that the methanolic extract of V. cinerea leaves and ethanol extract of T. procumbens stems possessed high inhibitory activates against dengue virus that worth more investigation.

  13. Detection and genetic relationship of dengue virus sequences in seventeen-year-old paraffin-embedded samples from Cuba.

    Science.gov (United States)

    Sariol, C A; Pelegrino, J L; Martinez, A; Arteaga, E; Kouri, G; Guzman, M G

    1999-12-01

    This study describes the use of the reverse transcriptase-polymerase chain reaction (RT-PCR) to generate dengue 2 amplicons from paraffin-embedded autopsy tissues collected in Cuba 17 years ago. The presumptive diagnoses had been made only by clinical evolution without serologic confirmation. This study confirms once again that dengue 2 virus was directly associated with the fatal cases in children and illustrates the potential of the RT-PCR for retrospective diagnosis of dengue cases 17 years after death. A close similarity in the genomic sequences of the dengue 2 RNA detected in tissue samples from fatal cases and those dengue 2 Cuban strains that had been previously investigated confirms the appropriate genomic classification of the etiologic agent associated with the 1981 dengue hemorrhagic fever Cuban epidemic.

  14. Differential Expression of Toll-like Receptors in Dendritic Cells of Patients with Dengue during Early and Late Acute Phases of the Disease

    NARCIS (Netherlands)

    Torres, Silvia; Carlos Hernandez, Juan; Giraldo, Diana; Arboleda, Margarita; Rojas, Mauricio; Smit, Jolanda M.; Urcuqui-Inchima, Silvio

    2013-01-01

    Background: Dengue hemorrhagic fever (DHF) is observed in individuals that have pre-existing heterotypic dengue antibodies and is associated with increased viral load and high levels of pro-inflammatory cytokines early in infection. Interestingly, a recent study showed that dengue virus infection in

  15. Functional Transplant of a Dengue Virus Serotype 3 (DENV3)-Specific Human Monoclonal Antibody Epitope into DENV1

    Science.gov (United States)

    Messer, William B.; Yount, Boyd L.; Royal, Scott R.; de Alwis, Ruklanthi; Widman, Douglas G.; Smith, Scott A.; Crowe, James E.; Pfaff, Jennifer M.; Kahle, Kristen M.; Doranz, Benjamin J.; Ibarra, Kristie D.; Harris, Eva

    2016-01-01

    ABSTRACT The four dengue virus (DENV) serotypes, DENV1 through 4, are endemic throughout tropical and subtropical regions of the world. While first infection confers long-term protective immunity against viruses of the infecting serotype, a second infection with virus of a different serotype carries a greater risk of severe dengue disease, including dengue hemorrhagic fever and dengue shock syndrome. Recent studies demonstrate that humans exposed to DENV infections develop neutralizing antibodies that bind to quaternary epitopes formed by the viral envelope (E) protein dimers or higher-order assemblies required for the formation of the icosahedral viral envelope. Here we show that the quaternary epitope target of the human DENV3-specific neutralizing monoclonal antibody (MAb) 5J7 can be partially transplanted into a DENV1 strain by changing the core residues of the epitope contained within a single monomeric E molecule. MAb 5J7 neutralized the recombinant DENV1/3 strain in cell culture and was protective in a mouse model of infection with the DENV1/3 strain. However, the 5J7 epitope was only partially recreated by transplantation of the core residues because MAb 5J7 bound and neutralized wild-type (WT) DENV3 better than the DENV1/3 recombinant. Our studies demonstrate that it is possible to transplant a large number of discontinuous residues between DENV serotypes and partially recreate a complex antibody epitope, while retaining virus viability. Further refinement of this approach may lead to new tools for measuring epitope-specific antibody responses and new vaccine platforms. IMPORTANCE Dengue virus is the most important mosquito-borne pathogen of humans worldwide, with approximately one-half the world's population living in regions where dengue is endemic. Dengue immunity following infection is robust and thought to be conferred by antibodies raised against the infecting virus. However, the specific viral components that these antibodies recognize and how they

  16. Genetic characterization of dengue virus type 3 isolates in the State of Rio de Janeiro, 2001

    Directory of Open Access Journals (Sweden)

    M.P. Miagostovich

    2002-08-01

    Full Text Available The genetic characterization of dengue virus type 3 (DEN-3 strains isolated from autochthonous cases in the State of Rio de Janeiro, Brazil, in 2001 is presented. Restriction site-specific (RSS-PCR performed on 22 strains classified the Brazilian DEN-3 viruses as subtype C, a subtype that contains viruses from Sri Lanka, India, Africa and recent isolates from Central America. Nucleic acid sequencing (positions 278 to 2550 of one DEN-3 strain confirmed the origin of these strains, since genotype III - classified by sequencing - and RSS-PCR subtype C are correlated. This genetic subtype has been associated with hemorrhagic dengue epidemics and the information provided here could be useful to implement appropriate prevention and control measures.

  17. Vitamin D-Regulated MicroRNAs: Are They Protective Factors against Dengue Virus Infection?

    Directory of Open Access Journals (Sweden)

    John F. Arboleda

    2016-01-01

    Full Text Available Over the last few years, an increasing body of evidence has highlighted the critical participation of vitamin D in the regulation of proinflammatory responses and protection against many infectious pathogens, including viruses. The activity of vitamin D is associated with microRNAs, which are fine tuners of immune activation pathways and provide novel mechanisms to avoid the damage that arises from excessive inflammatory responses. Severe symptoms of an ongoing dengue virus infection and disease are strongly related to highly altered production of proinflammatory mediators, suggesting impairment in homeostatic mechanisms that control the host’s immune response. Here, we discuss the possible implications of emerging studies anticipating the biological effects of vitamin D and microRNAs during the inflammatory response, and we attempt to extrapolate these findings to dengue virus infection and to their potential use for disease management strategies.

  18. Dengue Virus Type 2: Protein Binding and Active Replication in Human Central Nervous System Cells

    Directory of Open Access Journals (Sweden)

    Ma Isabel Salazar

    2013-01-01

    Full Text Available An increased number of dengue cases with neurological complications have been reported in recent years. The lack of reliable animal models for dengue has hindered studies on dengue virus (DENV pathogenesis and cellular tropism in vivo. We further investigate the tropism of DENV for the human central nervous system (CNS, characterizing DENV interactions with cell surface proteins in human CNS cells by virus overlay protein binding assays (VOPBA and coimmunoprecipitations. In VOPBA, three membrane proteins (60, 70, and 130 kDa from the gray matter bound the entire virus particle, whereas only a 70 kDa protein bound in white matter. The coimmunoprecipitation assays revealed three proteins from gray matter consistently binding virus particles, one clearly distinguishable protein (~32 kDa and two less apparent proteins (100 and 130 kDa. Monoclonal anti-NS3 targeted the virus protein in primary cell cultures of human CNS treated with DENV-2, which also stained positive for NeuH, a neuron-specific marker. Thus, our results indicate (1 that DENV-2 exhibited a direct tropism for human neurons and (2 that human neurons sustain an active DENV replication as was demonstrated by the presence of the NS3 viral antigen in primary cultures of these cells treated with DENV-2.

  19. Molecular detection of Mayaro virus during a dengue outbreak in the state of Mato Grosso, Central-West Brazil

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    Nayara Zuchi

    2014-09-01

    Full Text Available Mayaro virus (MAYV is frequently reported in Pan-Amazonia. The aim of this study was to investigate the circulation of alphaviruses during a dengue outbreak in the state of Mato Grosso, Brazil. Serum samples from dengue-suspected patients were subjected to multiplex semi-nested reverse transcriptase polymerase chain reaction for 11 flaviviruses and five alphaviruses, to nucleotide sequencing and to viral isolation. MAYV was detected in 15 (2.5% of 604 patients. Twelve were co-infected with dengue virus 4, which was isolated from 10 patients. The molecular detection of MAYV in dengue-suspected patients suggests that other arboviruses may be silently circulating during dengue outbreaks in Brazil.

  20. Molecular detection of Mayaro virus during a dengue outbreak in the state of Mato Grosso, Central-West Brazil.

    Science.gov (United States)

    Zuchi, Nayara; Heinen, Letícia Borges da Silva; Santos, Marcelo Adriano Mendes dos; Pereira, Fernanda Carla; Slhessarenko, Renata Dezengrini

    2014-09-01

    Mayaro virus (MAYV) is frequently reported in Pan-Amazonia. The aim of this study was to investigate the circulation of alphaviruses during a dengue outbreak in the state of Mato Grosso, Brazil. Serum samples from dengue-suspected patients were subjected to multiplex semi-nested reverse transcriptase polymerase chain reaction for 11 flaviviruses and five alphaviruses, to nucleotide sequencing and to viral isolation. MAYV was detected in 15 (2.5%) of 604 patients. Twelve were co-infected with dengue virus 4, which was isolated from 10 patients. The molecular detection of MAYV in dengue-suspected patients suggests that other arboviruses may be silently circulating during dengue outbreaks in Brazil.

  1. KEJADIAN INFEKSI ULANG VIRUS DENGUE BERDASAR RESPON IMUN HUMORALNYA PADA PENDERITA DBD DI DUA RUMAH SAKIT DI DKI JAKARTA

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    Djoko Yuwono

    2012-10-01

    Full Text Available Demam Berdarah Dengue (DBD merupakan penyakit endemik di Indonesia. Upaya pencegahan dengan imunisasi Dengue menghadapi beberapa kendala. Dewasa ini telah dilakukan penelitian dan pengembangan propfilaksi DBD di beberapa negara di Asia. Penelitian ini mencoba memberikan masukan mengenai pola infeksi ulang virus Dengue pada penderita DBD di dua RS di Jakarta. Telah diperiksa sebanyak  49 penderita tersangka Demam Berdarah Dengue di RSPI dan RS Pasar Rebo Jakarta. Konfirmasi DBD dilakukan dengan menentukan serokonversi anti Dengue menggunakan Uji Hambatan Hemaglutinasi (HI terhadap ke empat antigen Dengue, DV-1; DV-2; DV-3 dan DV-4. Selain itu dilakukan uji kualitatif untuk mendeteksi IgM anti Dengue dengan Uji Dengue Strip, Enzyme Immuno Assay (EIA. Hasil pengamatan menunjukkan bahwa dari 49 penderita tersangka DBD ditemukan 19 penderita (38,8% infeksi primer dan 11 penderita (22,4% infeksi sekunder DBD; 16,3% presumptif dan sisanya 22,4% seronegatif Dengue. Hasil pemeriksaan kuantitatif dengan Uji Hambatan Hemagalutinasi menunjukkan bahwa telah terjadi infeksi ulang oleh virus Dengue dengan gambaran sebagai berikut, yaitu: 2,0% (1 orang terinfeksi DV-1 dan DV-3; 4,08% (2 orang terinfeksi DV-2; 10,2% (5 orang terinfeksi DV-4. Selain itu ditemukan adanya koinfeksi yaitu: terinfeksi DV-1+2 dan DV-1+3 masing-masing sebesar 2,0% (1 org; terinfeksi DV-3+4 sebesar 4,08% (2 orang dan terinfeksi DV-1+2+3+4 sebesar 30,6% (15 orang. Hasil penelitian ini menunjukkan bahwa 30,6% penderita DBD dengan komposisi anti DV-1+2+3+4 temyata masih dapat terkena Demam Berdarah Dengue.   Kata kunci: penderita DBD; serologi; infeksi ulang dengue

  2. Exantema hemorrágico por virus dengue inducido por ácido acetil-salicílico Haemorrhagic exanthema due to dengue virus induced by acetylsalicylic acid

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    L. Valerio

    2006-12-01

    Full Text Available El dengue, enfermedad infecciosa vírica propia de los climas tropicales, se considera una patología reemergente que ha dado lugar a graves epidemias en la última década. En la expansión del virus y de su mosquito vector se barajan factores relacionados con la alteración humana del medio, con la rapidez en el tránsito de mercancias y personas y debidos al cambio climático. Como reflejo de ello, se asiste a un aumento de casos importados que, al ser una enfermedad con periodo de incubación corto (7-10 días, afecta especialmente a turistas procedentes de áreas endémicas. El reconocimiento de los antecedentes personales de viajes, de los síntomas-guía de la enfermedad y de las potenciales complicaciones (dengue hemorrágico deben ser incluidos en una anamnesis para el estudio de fiebre de origen desconocido o de exantema febril. Se presenta el caso de una paciente cuya clínica de dengue clásico se agravó por el autotratamiento con ácido acetil-salicílico.Dengue fever, a viral infectious disease characteristic of tropical climates, is considered to be a re-emergent pathology responsible for several serious outbreaks in the last decade. Some factors have been involved in the spread of the virus and its vectorial mosquito carrier: human alteration of the ecosystems, improvement and speed in the transit of goods and people and climate changes. As a reflection of this, an increase in imported cases is probable, especially in tourists coming from endemic areas, considering its short period of incubation (7-10 days. The recognition of personal antecedents of journeys, the main symptoms of the disease and the potential presence of complications (haemorrhagic dengue should be included in the examination of fever of unknown origin or feverish exanthema. The case of a patient is presented whose clinical picture of classic dengue fever was worsened by self-treatment with acetylsalicylic acid.

  3. Phylogeography and molecular epidemiology of an epidemic strain of dengue virus type 1 in Sri Lanka.

    Science.gov (United States)

    Ocwieja, Karen E; Fernando, Anira N; Sherrill-Mix, Scott; Sundararaman, Sesh A; Tennekoon, Rashika N; Tippalagama, Rashmi; Krishnananthasivam, Shivankari; Premawansa, Gayani; Premawansa, Sunil; De Silva, Aruna Dharshan

    2014-08-01

    In 2009, a severe epidemic of dengue disease occurred in Sri Lanka, with higher mortality and morbidity than any previously recorded epidemic in the country. It corresponded to a shift to dengue virus 1 as the major disease-causing serotype in Sri Lanka. Dengue disease reached epidemic levels in the next 3 years. We report phylogenetic evidence that the 2009 epidemic DENV-1 strain continued to circulate within the population and caused severe disease in the epidemic of 2012. Bayesian phylogeographic analyses suggest that the 2009 Sri Lankan epidemic DENV-1 strain may have traveled directly or indirectly from Thailand through China to Sri Lanka, and after spreading within the Sri Lankan population, it traveled to Pakistan and Singapore. Our findings delineate the dissemination route of a virulent DENV-1 strain in Asia. Understanding such routes will be of particular importance to global control efforts.

  4. The relevance of dengue virus genotypes surveillance at country level before vaccine approval.

    Science.gov (United States)

    Usme-Ciro, José A; Méndez, Jairo A; Laiton, Katherine D; Páez, Andrés

    2014-01-01

    Dengue is a major threat for public health in tropical and subtropical countries around the world. In the absence of a licensed vaccine and effective antiviral therapies, control measures have been based on education activities and vector elimination. Current efforts for developing a vaccine are both promising and troubling. At the advent of the introduction of a tetravalent dengue vaccine, molecular surveillance of the circulating genotypes in different geographical regions has gained considerable importance. A growing body of in vitro, preclinical, and clinical phase studies suggest that vaccine conferred protection in a geographical area could depends on the coincidence of the dengue virus genotypes included in the vaccine and those circulating. In this review we present the state-of-the-art in this field, highlighting the need of deeper knowledge on neutralizing immune response for making decisions about future vaccine approval and the potential need for different vaccine composition for regional administration.

  5. T cell immunity to dengue virus and implications for vaccine design.

    Science.gov (United States)

    Rivino, Laura

    2016-01-01

    Dengue virus infections are increasing at an alarming rate in many tropical and subtropical countries and represent, in some of these areas, a leading cause of hospitalization and death among children. The lack of a clear definition of the correlates of protection from severe dengue disease represents a major hurdle for vaccine development. In particular, the role of T lymphocytes during dengue infection remains unclear and there is evidence suggesting that these cells may be important for both protective immunity and/or immunopathology. In this review we discuss the findings that support a protective role of T cells versus those supporting their involvement in pathogenesis. A better understanding of T cell immunity is urgently needed for the development of safe and efficacious vaccines.

  6. Epidemiological and Molecular Characterization of Dengue Virus Circulating in Bhutan, 2013-2014.

    Science.gov (United States)

    Zangmo, Sangay; Klungthong, Chonticha; Chinnawirotpisan, Piyawan; Tantimavanich, Srisurang; Kosoltanapiwat, Nathamon; Thaisomboonsuk, Butsaya; Phuntsho, Kelzang; Wangchuk, Sonam; Yoon, In-Kyu; Fernandez, Stefan

    2015-01-01

    Dengue is one of the most significant public health problems in tropical and subtropical countries, and is increasingly being detected in traditionally non-endemic areas. In Bhutan, dengue virus (DENV) has only recently been detected and limited information is available. In this study, we analyzed the epidemiological and molecular characteristics of DENV in two southern districts in Bhutan from 2013-2014. During this period, 379 patients were clinically diagnosed with suspected dengue, of whom 119 (31.4%) were positive for DENV infection by NS1 ELISA and/or nested RT-PCR. DENV serotypes 1, 2 and 3 were detected with DENV-1 being predominant. Phylogenetic analysis of DENV-1 using envelope gene demonstrated genotype V, closely related to strains from northern India.

  7. Seroprevalence of past dengue virus infection among children and adolescents in Singapore.

    Science.gov (United States)

    Ang, Li Wei; Cutter, Jeffery; James, Lyn; Goh, Kee Tai

    2015-12-01

    We conducted a pediatric seroprevalence study of dengue virus (DENV) infection in Singapore, a dengue endemic city-state. Residual sera from 1,200 Singapore residents aged 1-17 years seen in two hospitals between 2008 and 2010 were tested for anti-DENV IgG antibodies. The overall seroprevalence was 10.4% (95%CI: 8.7-12.1%). There had been a marked decline in seroprevalence in the 15-19-year age group over the last three decades, while the prevalence in the 1-5-year olds (12.6%) was significantly higher than that of the 1996-1997 pediatric survey (0.8%). The overall dengue seroprevalence in children and adolescents remained low.

  8. Epidemiological and Molecular Characterization of Dengue Virus Circulating in Bhutan, 2013-2014.

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    Sangay Zangmo

    Full Text Available Dengue is one of the most significant public health problems in tropical and subtropical countries, and is increasingly being detected in traditionally non-endemic areas. In Bhutan, dengue virus (DENV has only recently been detected and limited information is available. In this study, we analyzed the epidemiological and molecular characteristics of DENV in two southern districts in Bhutan from 2013-2014. During this period, 379 patients were clinically diagnosed with suspected dengue, of whom 119 (31.4% were positive for DENV infection by NS1 ELISA and/or nested RT-PCR. DENV serotypes 1, 2 and 3 were detected with DENV-1 being predominant. Phylogenetic analysis of DENV-1 using envelope gene demonstrated genotype V, closely related to strains from northern India.

  9. First Outbreak of Dengue Hemorrhagic Fever, Bangladesh

    OpenAIRE

    Rahman, Mahbubur; Rahman, Khalilur; Siddque, A. K.; Shoma, Shereen; A. H. M. Kamal; Ali, K.S.; Nisaluk, Ananda; Breiman, Robert F

    2002-01-01

    During the first countrywide outbreak of dengue hemorrhagic fever in Bangladesh, we conducted surveillance for dengue at a hospital in Dhaka. Of 176 patients, primarily adults, found positive for dengue, 60.2% had dengue fever, 39.2% dengue hemorrhagic fever, and 0.6% dengue shock syndrome. The Dengue virus 3 serotype was detected in eight patients.

  10. DENGUE VACCINES.

    Science.gov (United States)

    Thisyakorn, Usa; Thisyakorn, Chule

    2015-01-01

    The uniqueness of the dengue viruses (DENVs) and the spectrum of disease resulting from infection have made dengue vaccine development difficult. Several vaccine candidates are currently being evaluated in clinical studies. The candidate currently at the most advanced clinical development stage, a live-attenuated tetravalent vaccine based on the chimeric yellow fever-dengue virus (CYD-TDV), has progressed to Phase 3 efficacy studies. Several other live-attenuated vaccines, as well as subunit, DNA, and purified inactivated vaccine candidates are at earlier stages of clinical development. Additional technological approaches, such as virus-vectored and Virus-Like Particles (VLP)-based vaccines are under evaluation in preclinical studies.

  11. A Simple Reverse Transcription-Polymerase Chain Reaction for Dengue Type 2 Virus Identification

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    Figueiredo Luiz Tadeu M

    1997-01-01

    Full Text Available We show here a simplified reverse transcription-polymerase chain reaction (RT-PCR for identification of dengue type 2 virus. Three dengue type 2 virus strains, isolated from Brazilian patients, and yellow fever vaccine 17DD, as a negative control, were used in this study. C6/36 cells were infected with the virus, and tissue culture fluids were collected after 7 days of infection period. The RT-PCR, a combination of RT and PCR done after a single addition of reagents in a single reaction vessel was carried out following a digestion of virus with 1% Nonidet P-40. The 50ml assay reaction mixture included 50 pmol of a dengue type 2 specific primer pair amplifying a 210 base pair sequence of the envelope protein gene, 0.1 mM of the four deoxynucleoside triphosphates, 7.5U of reverse transcriptase, and 1U of thermostable Taq DNA polymerase. The reagent mixture was incubated for 15 min at 37oC for RT followed by a variable amount of cycles of two-step PCR amplification (92oC for 60 sec, 53oC for 60 sec with slow temperature increment. The PCR products were subjected to 1.7% agarose gel electrophoresis and visualized with UV light after gel incubation in ethidium bromide solution. DNA bands were observed after 25 and 30 cycles of PCR. Virus amount as low as 102.8 TCID50/ml was detected by RT-PCR. Specific DNA amplification was observed with the three dengue type 2 strains. This assay has advantages compared to other RT-PCRs: it avoids laborious extraction of virus RNA; the combination of RT and PCR reduces assay time, facilitates the performance and reduces risk of contamination; the two-step PCR cycle produces a clear DNA amplification, saves assay time and simplifies the technique

  12. Temporal dynamics of the transcriptional response to dengue virus infection in Nicaraguan children.

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    Stephen J Popper

    Full Text Available Dengue is the most prevalent mosquito-borne human illness worldwide. The ability to predict disease severity during the earliest days of the illness is a long-sought, but unachieved goal.We examined human genome-wide transcript abundance patterns in daily peripheral blood mononuclear cell (PBMC samples from 41 children hospitalized with dengue virus (DENV infection in Nicaragua, as well as 8 healthy control subjects. Nine patients had primary dengue fever (DF1, 11 had dengue fever with serologic evidence of prior DENV infection, i.e., secondary dengue fever (DF2, 12 had dengue hemorrhagic fever (DHF, and 9 had dengue shock syndrome (DSS. We identified 2,092 genes for which transcript abundance differed significantly between patients on days 3-6 of fever and healthy subjects (FDR<1%. Prior DENV infection explained the greatest amount of variation in gene expression among patients. The number of differentially expressed genes was greatest on fever day 3 in patients with DF1, while the number in patients with DF2 or DHF/DSS was greatest on day 5. Genes associated with the mitotic cell cycle and B cell differentiation were expressed at higher levels, and genes associated with signal transduction and cell adhesion were expressed at lower levels, in patients versus healthy controls. On fever day 3, a set of interferon-stimulated gene transcripts was less abundant in patients who subsequently developed DSS than in other patient groups (p<0.05, ranksum. Patients who later developed DSS also had higher levels of transcripts on day 3 associated with mitochondrial function (p<0.01, ranksum. These day 3 transcript abundance findings were not evident on subsequent fever days.In conclusion, we identified differences in the timing and magnitude of human gene transcript abundance changes in DENV patients that were associated with serologic evidence of prior infection and with disease severity. Some of these differential features may predict the outcome of DENV

  13. HELZ2 Is an IFN Effector Mediating Suppression of Dengue Virus

    Science.gov (United States)

    Fusco, Dahlene N.; Pratt, Henry; Kandilas, Stephen; Cheon, Scarlett Se Yun; Lin, Wenyu; Cronkite, D. Alex; Basavappa, Megha; Jeffrey, Kate L.; Anselmo, Anthony; Sadreyev, Ruslan; Yapp, Clarence; Shi, Xu; O'Sullivan, John F.; Gerszten, Robert E.; Tomaru, Takuya; Yoshino, Satoshi; Satoh, Tetsurou; Chung, Raymond T.

    2017-01-01

    Flaviviral infections including dengue virus are an increasing clinical problem worldwide. Dengue infection triggers host production of the type 1 IFN, IFN alpha, one of the strongest and broadest acting antivirals known. However, dengue virus subverts host IFN signaling at early steps of IFN signal transduction. This subversion allows unbridled viral replication which subsequently triggers ongoing production of IFN which, again, is subverted. Identification of downstream IFN antiviral effectors will provide targets which could be activated to restore broad acting antiviral activity, stopping the signal to produce endogenous IFN at toxic levels. To this end, we performed a targeted functional genomic screen for IFN antiviral effector genes (IEGs), identifying 56 IEGs required for antiviral effects of IFN against fully infectious dengue virus. Dengue IEGs were enriched for genes encoding nuclear receptor interacting proteins, including HELZ2, MAP2K4, SLC27A2, HSP90AA1, and HSP90AB1. We focused on HELZ2 (Helicase With Zinc Finger 2), an IFN stimulated gene and IEG which encodes a promiscuous nuclear factor coactivator that exists in two isoforms. The two unique HELZ2 isoforms are both IFN responsive, contain ISRE elements, and gene products increase in the nucleus upon IFN stimulation. Chromatin immunoprecipitation-sequencing revealed that the HELZ2 complex interacts with triglyceride-regulator LMF1. Mass spectrometry revealed that HELZ2 knockdown cells are depleted of triglyceride subsets. We thus sought to determine whether HELZ2 interacts with a nuclear receptor known to regulate immune response and lipid metabolism, AHR, and identified HELZ2:AHR interactions via co-immunoprecipitation, found that AHR is a dengue IEG, and that an AHR ligand, FICZ, exhibits anti-dengue activity. Primary bone marrow derived macrophages from HELZ2 knockout mice, compared to wild type controls, exhibit enhanced dengue infectivity. Overall, these findings reveal that IFN antiviral

  14. Simultaneous outbreaks of dengue, chikungunya and Zika virus infections: diagnosis challenge in a returning traveller with nonspecific febrile illness

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    E. Moulin

    2016-05-01

    Full Text Available Zika virus is an emerging flavivirus that is following the path of dengue and chikungunya. The three Aedes-borne viruses cause simultaneous outbreaks with similar clinical manifestations which represents a diagnostic challenge in ill returning travellers. We report the first Zika virus infection case imported to Switzerland and present a diagnostic algorithm.

  15. Characterization of Human CD8 T Cell Responses in Dengue Virus-Infected Patients from India.

    Science.gov (United States)

    Chandele, Anmol; Sewatanon, Jaturong; Gunisetty, Sivaram; Singla, Mohit; Onlamoon, Nattawat; Akondy, Rama S; Kissick, Haydn Thomas; Nayak, Kaustuv; Reddy, Elluri Seetharami; Kalam, Haroon; Kumar, Dhiraj; Verma, Anil; Panda, HareKrushna; Wang, Siyu; Angkasekwinai, Nasikarn; Pattanapanyasat, Kovit; Chokephaibulkit, Kulkanya; Medigeshi, Guruprasad R; Lodha, Rakesh; Kabra, Sushil; Ahmed, Rafi; Murali-Krishna, Kaja

    2016-12-15

    Epidemiological studies suggest that India has the largest number of dengue virus infection cases worldwide. However, there is minimal information about the immunological responses in these patients. CD8 T cells are important in dengue, because they have been implicated in both protection and immunopathology. Here, we provide a detailed analysis of HLA-DR(+) CD38(+) and HLA-DR(-) CD38(+) effector CD8 T cell subsets in dengue patients from India and Thailand. Both CD8 T cell subsets expanded and expressed markers indicative of antigen-driven proliferation, tissue homing, and cytotoxic effector functions, with the HLA-DR(+) CD38(+) subset being the most striking in these effector qualities. The breadth of the dengue-specific CD8 T cell response was diverse, with NS3-specific cells being the most dominant. Interestingly, only a small fraction of these activated effector CD8 T cells produced gamma interferon (IFN-γ) when stimulated with dengue virus peptide pools. Transcriptomics revealed downregulation of key molecules involved in T cell receptor (TCR) signaling. Consistent with this, the majority of these CD8 T cells remained IFN-γ unresponsive even after TCR-dependent polyclonal stimulation (anti-CD3 plus anti-CD28) but produced IFN-γ by TCR-independent polyclonal stimulation (phorbol 12-myristate 13-acetate [PMA] plus ionomycin). Thus, the vast majority of these proliferating, highly differentiated effector CD8 T cells probably acquire TCR refractoriness at the time the patient is experiencing febrile illness that leads to IFN-γ unresponsiveness. Our studies open novel avenues for understanding the mechanisms that fine-tune the balance between CD8 T cell-mediated protective versus pathological effects in dengue.

  16. 登革病毒样颗粒疫苗的研究现状%Review of study on Dengue virus-like particles vaccine

    Institute of Scientific and Technical Information of China (English)

    付春云; 戴盛明; 周俊梅

    2013-01-01

    登革病毒引起的疾病是一种严重威胁人类健康的蚊媒性急性传染病.但至今仍没有获批准的疫苗可用.近年,一种新的病毒样颗粒(VLPs)能使免疫小鼠产生中和性抗体和持久、特异的T淋巴免疫记忆细胞.VLPs克服了传统疫苗的很多不足,具有较大应用潜力.%The infection caused by Dengue virus is an acute life-threatening mosquito-borne infectious disease.So far,an effective and safe vaccine for dengue is not yet available.Recently a new virus-like particles vaccine was developed which induces the vaccinated mice to produce neutralizing antibody,and long-lasting virus-specific memory T lymphocytes.What more,it also can be widely explored by using yeast expression system.Its special priorities make it become a hopeful ideal dengue vaccine.

  17. Reemergence of dengue virus type-3 (subtype-III in India: Implications for increased incidence of DHF & DSS

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    Tewari KN

    2006-07-01

    Full Text Available Abstract Background Dengue virus infection has recently taken endemic proportion in India implicating all the four known dengue serotypes. There was a major dengue outbreak in northern India including Delhi in October- December, 2003 and again in 2004. We have carried out a detailed investigation of the 2004 outbreak by Serosurveillance, RT-PCR, nested PCR, virus isolation and genotyping. We also report the molecular epidemiological investigation of these outbreaks. Results The serological investigation of 162 suspected serum samples using an in-house dengue dipstick ELISA revealed 11%-IgM, 51%-IgG and 38%-both IgM and IgG antibody positivity. The RT-PCR analysis revealed presence of dengue RNA in 17 samples. Further subtyping and genotyping by nested PCR and nucleotide sequencing of C-prM gene junction revealed the association of subtype III of dengue virus type 3 in the outbreak. Conclusion The sudden shifting and dominance of the dengue virus serotype-3 (subtype III replacing the earlier circulating serotype-2 (subtype IV is a point of major concern and may be attributed to increased incidence of DHF and DSS in India.

  18. Dengue virus requires the CC-chemokine receptor CCR5 for replication and infection development.

    Science.gov (United States)

    Marques, Rafael E; Guabiraba, Rodrigo; Del Sarto, Juliana L; Rocha, Rebeca F; Queiroz, Ana Luiza; Cisalpino, Daniel; Marques, Pedro E; Pacca, Carolina C; Fagundes, Caio T; Menezes, Gustavo B; Nogueira, Maurício L; Souza, Danielle G; Teixeira, Mauro M

    2015-08-01

    Dengue is a mosquito-borne disease that affects millions of people worldwide yearly. Currently, there is no vaccine or specific treatment available. Further investigation on dengue pathogenesis is required to better understand the disease and to identify potential therapeutic targets. The chemokine system has been implicated in dengue pathogenesis, although the specific role of chemokines and their receptors remains elusive. Here we describe the role of the CC-chemokine receptor CCR5 in Dengue virus (DENV-2) infection. In vitro experiments showed that CCR5 is a host factor required for DENV-2 replication in human and mouse macrophages. DENV-2 infection induces the expression of CCR5 ligands. Incubation with an antagonist prevents CCR5 activation and reduces DENV-2 positive-stranded (+) RNA inside macrophages. Using an immunocompetent mouse model of DENV-2 infection we found that CCR5(-/-) mice were resistant to lethal infection, presenting at least 100-fold reduction of viral load in target organs and significant reduction in disease severity. This phenotype was reproduced in wild-type mice treated with CCR5-blocking compounds. Therefore, CCR5 is a host factor required for DENV-2 replication and disease development. Targeting CCR5 might represent a therapeutic strategy for dengue fever. These data bring new insights on the association between viral infections and the chemokine receptor CCR5.

  19. Human Immune Responses to Dengue Virus Infection: lessons learned from prospective cohort studies

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    Timothy P Endy

    2014-04-01

    Full Text Available Dengue virus (DENV continues to spread globally and is a major cause of morbidity and mortality. Currently there is no antiviral treatment to diminish severe illness or a vaccine to induce protection from infection. An effective dengue vaccine that protects against all four DENV serotypes is a high priority for endemic countries and several candidates are in development by various United States Federal Agencies and private pharmaceutical companies. Challenges faced by dengue vaccine developers include creating tetravalent formulations that provide tetravalent protection, the lack of a correlate of protective immunity, a changing viral landscape as DENV evolves, and a complex viral-host pathogenesis that can result in a spectrum of illness from subclinical infection to severe hemorrhagic fever. There have been a number of long-term prospective studies on DENV transmission and dengue severity that have provided invaluable information on DENV epidemiology and pathogenesis of this disease. In this section we will review the critical lessons learned from these studies and their application for dengue vaccine development.

  20. Dengue virus type 2 infections of Aedes aegypti are modulated by the mosquito's RNA interference pathway.

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    Irma Sánchez-Vargas

    2009-02-01

    Full Text Available A number of studies have shown that both innate and adaptive immune defense mechanisms greatly influence the course of human dengue virus (DENV infections, but little is known about the innate immune response of the mosquito vector Aedes aegypti to arbovirus infection. We present evidence here that a major component of the mosquito innate immune response, RNA interference (RNAi, is an important modulator of mosquito infections. The RNAi response is triggered by double-stranded RNA (dsRNA, which occurs in the cytoplasm as a result of positive-sense RNA virus infection, leading to production of small interfering RNAs (siRNAs. These siRNAs are instrumental in degradation of viral mRNA with sequence homology to the dsRNA trigger and thereby inhibition of virus replication. We show that although dengue virus type 2 (DENV2 infection of Ae. aegypti cultured cells and oral infection of adult mosquitoes generated dsRNA and production of DENV2-specific siRNAs, virus replication and release of infectious virus persisted, suggesting viral circumvention of RNAi. We also show that DENV2 does not completely evade RNAi, since impairing the pathway by silencing expression of dcr2, r2d2, or ago2, genes encoding important sensor and effector proteins in the RNAi pathway, increased virus replication in the vector and decreased the extrinsic incubation period required for virus transmission. Our findings indicate a major role for RNAi as a determinant of DENV transmission by Ae. aegypti.

  1. Virucidal activity of Colombian Lippia essential oils on dengue virus replication in vitro

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    Raquel Elvira Ocazionez

    2010-05-01

    Full Text Available The inhibitory effect of Lippia alba and Lippia citriodora essential oils on dengue virus serotypes replication in vitro was investigated. The cytotoxicity (CC50 was evaluated by the MTT assay and the mode of viral inhibitory effect was investigated with a plaque reduction assay. The virus was treated with the essential oil for 2 h at 37ºC before cell adsorption and experiments were conducted to evaluate inhibition of untreated-virus replication in the presence of oil. Antiviral activity was defined as the concentration of essential oil that caused 50% reduction of the virus plaque number (IC50. L. alba oil resulted in less cytotoxicity than L. citriodora oil (CC50: 139.5 vs. 57.6 μg/mL. Virus plaque reduction for all four dengue serotypes was observed by treatment of the virus before adsorption on cell. The IC50 values for L. alba oil were between 0.4-32.6 μg/mL and between 1.9-33.7 μg/mL for L. citriodora oil. No viral inhibitory effect was observed by addition of the essential oil after virus adsorption. The inhibitory effect of the essential oil seems to cause direct virus inactivation before adsorption on host cell.

  2. Virucidal activity of Colombian Lippia essential oils on dengue virus replication in vitro.

    Science.gov (United States)

    Ocazionez, Raquel Elvira; Meneses, Rocio; Torres, Flor Angela; Stashenko, Elena

    2010-05-01

    The inhibitory effect of Lippia alba and Lippia citriodora essential oils on dengue virus serotypes replication in vitro was investigated. The cytotoxicity (CC50) was evaluated by the MTT assay and the mode of viral inhibitory effect was investigated with a plaque reduction assay. The virus was treated with the essential oil for 2 h at 37 masculineC before cell adsorption and experiments were conducted to evaluate inhibition of untreated-virus replication in the presence of oil. Antiviral activity was defined as the concentration of essential oil that caused 50% reduction of the virus plaque number (IC50). L. alba oil resulted in less cytotoxicity than L. citriodora oil (CC50: 139.5 vs. 57.6 microg/mL). Virus plaque reduction for all four dengue serotypes was observed by treatment of the virus before adsorption on cell. The IC50 values for L. alba oil were between 0.4-32.6 microg/mL and between 1.9-33.7 microg/mL for L. citriodora oil. No viral inhibitory effect was observed by addition of the essential oil after virus adsorption. The inhibitory effect of the essential oil seems to cause direct virus inactivation before adsorption on host cell.

  3. Dengue Virus Utilizes a Novel Strategy for Translation Initiation When Cap-Dependent Translation Is Inhibited

    OpenAIRE

    Edgil, Dianna; Polacek, Charlotta; Harris, Eva

    2006-01-01

    Viruses have developed numerous mechanisms to usurp the host cell translation apparatus. Dengue virus (DEN) and other flaviviruses, such as West Nile and yellow fever viruses, contain a 5′ m7GpppN-capped positive-sense RNA genome with a nonpolyadenylated 3′ untranslated region (UTR) that has been presumed to undergo translation in a cap-dependent manner. However, the means by which the DEN genome is translated effectively in the presence of capped, polyadenylated cellular mRNAs is unknown. Th...

  4. Dengue virus serotype 2 infection alters midgut and carcass gene expression in the Asian tiger mosquito, Aedes albopictus

    Science.gov (United States)

    Hanley, Kathryn A.; Sundararajan, Anitha; Devitt, Nicholas P.; Schilkey, Faye D.; Hansen, Immo A.

    2017-01-01

    Background The Asian tiger mosquito, Aedes albopictus is currently an important vector for dengue, chikungunya and Zika virus, and its role in transmission of arthropod-borne viruses (arboviruses) may increase in the future due to its ability to colonize temperate regions. In contrast to Aedes aegypti, the dominant vector of dengue, chikungunya and Zika virus, genetic responses of Ae. albopictus upon infection with an arbovirus are not well characterized. Here we present a study of the changes in transcript expression in Ae. albopictus exposed to dengue virus serotype 2 via feeding on an artificial bloodmeal. Methodology/Principal findings We isolated midguts and midgut-free carcasses of Ae. albopictus fed on bloodmeals containing dengue virus as well as controls fed on virus-free control meals at day 1 and day 5 post-feeding. We confirmed infection of midguts from mosquitoes sampled on day 5 post-feeding via RT-PCR. RNAseq analysis revealed dynamic modulation of the expression of several putative immunity and dengue virus-responsive genes, some of whose expression was verified by qRT-PCR. For example, a serine protease gene was up-regulated in the midgut at 1 day post infection, which may potentially enhance mosquito susceptibility to dengue infection, while 14 leucine-rich repeat genes, previously shown to be involved in mosquito antiviral defenses, were down-regulated in the carcass at 5 days post infection. The number of significantly modulated genes decreased over time in midguts and increased in carcasses. Conclusion/Significance Dengue virus exposure results in the modulation of genes in a time- and site-specific manner. Previous literature on the interaction between mosquitoes and mosquito-borne pathogens suggests that most of the changes that occurred in Ae. albopictus exposed to DENV would favor virus infection. Many genes identified in this study warrant further characterization to understand their role in viral manipulation of and antiviral response of

  5. Induction of neutralizing antibodies against four serotypes of dengue viruses by MixBiEDIII, a tetravalent dengue vaccine.

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    Hui Zhao

    Full Text Available The worldwide expansion of four serotypes of dengue virus (DENV poses great risk to global public health. Several vaccine candidates are under development. However, none is yet available for humans. In the present study, a novel strategy to produce tetravalent DENV vaccine based on envelope protein domain III (EDIII was proposed. Tandem EDIIIs of two serotypes (type 1-2 and type 3-4 of DENV connected by a Gly-Ser linker ((Gly4Ser3 were expressed in E. coli, respectively. Then, the two bivalent recombinant EDIIIs were equally mixed to form the tetravalent vaccine candidate MixBiEDIII, and used to immunize BALB/c mice. The results showed that specific IgG and neutralizing antibodies against all four serotypes of DENV were successfully induced in the MixBiEDIII employing Freund adjuvant immunized mice. Furthermore, in the suckling mouse model, sera from mice immunized with MixBiEDIII provided significant protection against four serotypes of DENV challenge. Our data demonstrated that MixBiEDIII, as a novel form of subunit vaccine candidates, might have the potential to be further developed as a tetravalent dengue vaccine in the near future.

  6. Molecular characterisation of dengue virus type 1 reveals lineage replacement during circulation in Brazilian territory

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    Adriana Ribeiro Carneiro

    2012-09-01

    Full Text Available Dengue fever is the most important arbovirus infection found in tropical regions around the world. Dispersal of the vector and an increase in migratory flow between countries have led to large epidemics and severe clinical outcomes, such as dengue haemorrhagic fever and dengue shock syndrome. This study analysed the genetic variability of the dengue virus serotype 1 (DENV-1 in Brazil with regard to the full-length structural genes C/prM/M/E among 34 strains isolated during epidemics that occurred in the country between 1994-2011. Virus phylogeny and time of divergence were also evaluated with only the E gene of the strains isolated from 1994-2008. An analysis of amino acid differences between these strains and the French Guiana strain (FGA/89 revealed the presence of important nonsynonymous substitutions in the amino acid sequences, including residues E297 (Met→Thr and E338 (Ser→Leu. A phylogenetic analysis of E proteins comparing the studied isolates and other strains selected from the GenBank database showed that the Brazilian DENV-1 strains since 1982 belonged to genotype V. This analysis also showed that different introductions of strains from the 1990s represented lineage replacement, with the identification of three lineages that cluster all isolates from the Americas. An analysis of the divergence time of DENV-1 indicated that the lineage circulating in Brazil emerged from an ancestral lineage that originated approximately 44.35 years ago.

  7. Dengue virus infection-enhancing antibody activities against Indonesian strains in inhabitants of central Thailand.

    Science.gov (United States)

    Yamanaka, Atsushi; Oddgun, Duangjai; Chantawat, Nantarat; Okabayashi, Tamaki; Ramasoota, Pongrama; Churrotin, Siti; Kotaki, Tomohiro; Kameoka, Masanori; Soegijanto, Soegeng; Konishi, Eiji

    2016-04-01

    Dengue virus (DENV) infection-enhancing antibodies are a hypothetic factor to increase the dengue disease severity. In this study, we investigated the enhancing antibodies against Indonesian strains of DENV-1-4 in 50 healthy inhabitants of central Thailand (Bangkok and Uthai Thani). Indonesia and Thailand have seen the highest dengue incidence in Southeast Asia. The infection history of each subject was estimated by comparing his/her neutralizing antibody titers against prototype DENV-1-4 strains. To resolve the difficulty in obtaining foreign live viruses for use as assay antigens, we used a recombinant system to prepare single-round infectious dengue viral particles based on viral sequence information. Irrespective of the previously infecting serotype(s), most serum samples showed significantly higher enhancement titers against Indonesian DENV-2 strains than against Thai DENV-2 strains, whereas the opposite effect was observed for the DENV-3 strains. Equivalent enhancing activities were observed against both DENV-1 and DENV-4. These results suggest that the genotype has an impact on enhancing antibody activities against DENV-2 and DENV-3, because the predominant circulating genotypes of each serotype differ between Indonesia and Thailand.

  8. Human apolipoprotein A-I is associated with dengue virus and enhances virus infection through SR-BI.

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    Yujia Li

    Full Text Available Diseases caused by dengue virus (DV infection vary in severity, with symptoms ranging from mild fever to life threatening dengue hemorrhage fever (DHF and dengue shock syndrome (DSS. Clinical studies have shown that significant decrease in the level of lipoproteins is correlated with severe illness in DHF/DSS patients. Available evidence also indicates that lipoproteins including high-density lipoprotein (HDL and low-density lipoprotein (LDL are able to facilitate cell entry of HCV or other flaviviruses via corresponding lipoprotein receptors. In this study, we found that pre-incubation of DV with human serum leads to an enhanced DV infectivity in various types of cells. Such enhancement could be due to interactions between serum components and DV particles. Through co-immunoprecipitation we revealed that apolipoprotein A-I (ApoA-I, the major protein component in HDL, is associated with DV particles and is able to promote DV infection. Based on that observation, we further found that siRNA knockdown of the scavenger receptor class B type I (SR-BI, the cell receptor of ApoA-I, abolished the activity of ApoA-I in enhancement of DV infection. This suggests that ApoA-I bridges DV particles and cell receptor SR-BI and facilitates entry of DV into cells. FACS analysis of cell surface dengue antigen after virus absorption further confirmed that ApoA-I enhances DV infection via promoting initial attachment of the virus to cells. These findings illustrate a novel entry route of DV into cells, which may provide insights into the functional importance of lipoproteins in dengue pathogenesis.

  9. Monoclonal antibody mapping of the envelope glycoprotein of the dengue 2 virus, Jamaica.

    Science.gov (United States)

    Roehrig, J T; Bolin, R A; Kelly, R G

    1998-07-05

    Although dengue (DEN) virus is the etiologic agent of dengue fever, the most prevalent vector-borne viral disease in the world, precise information on the antigenic structure of the dengue virion is limited. We have prepared a set of murine monoclonal antibodies (MAbs) specific for the envelope (E) glycoprotein of DEN 2 virus and used these antibodies in a comprehensive biological and biochemical analysis to identify 16 epitopes. Following domain nomenclature developed for the related flavivirus, tick-borne encephalitis, three functional domains were identified. Five epitopes associated with domain A were arranged in three spatially independent regions. These A-domain epitopes were destroyed by reduction, and antibodies reactive with these epitopes were able to block virus hemagglutination, neutralize virus infectivity, and block virus-mediated cell membrane fusion. Domain-A epitopes were present on the full-length E glycoprotein, a 45-kDa tryptic peptide representing its first 400 amino acids (aa) and a 22-kDa tryptic peptide representing at least aa 1-120. Four epitopes mapped into domain B, as determined by their partial resistance to reduction and the localization of these epitopes on a 9-kDa tryptic or chymotryptic peptide fragment (aa 300-400). One domain-B-reactive MAb was also capable of binding to a DEN 2 synthetic peptide corresponding to aa 333-351 of the E glycoprotein, confirming the location of this domain. Domain-B epitopes elicited MAbs that were potent neutralizers of virus infectivity and blocked hemagglutination, but they did not block virus-mediated cell-membrane fusion. Domains A and B were spatially associated. As with tick-borne encephalitis virus, determination of domain C was more problematic; however, at least four epitopes had biochemical characteristics consistent with C-domain epitopes.

  10. RNA sensors enable human mast cell anti-viral chemokine production and IFN-mediated protection in response to antibody-enhanced dengue virus infection.

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    Michael G Brown

    Full Text Available Dengue hemorrhagic fever and/or dengue shock syndrome represent the most serious pathophysiological manifestations of human dengue virus infection. Despite intensive research, the mechanisms and important cellular players that contribute to dengue disease are unclear. Mast cells are tissue-resident innate immune cells that play a sentinel cell role in host protection against infectious agents via pathogen-recognition receptors by producing potent mediators that modulate inflammation, cell recruitment and normal vascular homeostasis. Most importantly, mast cells are susceptible to antibody-enhanced dengue virus infection and respond with selective cytokine and chemokine responses. In order to obtain a global view of dengue virus-induced gene regulation in mast cells, primary human cord blood-derived mast cells (CBMCs and the KU812 and HMC-1 mast cell lines were infected with dengue virus in the presence of dengue-immune sera and their responses were evaluated at the mRNA and protein levels. Mast cells responded to antibody-enhanced dengue virus infection or polyinosiniċpolycytidylic acid treatment with the production of type I interferons and the rapid and potent production of chemokines including CCL4, CCL5 and CXCL10. Multiple interferon-stimulated genes were also upregulated as well as mRNA and protein for the RNA sensors PKR, RIG-I and MDA5. Dengue virus-induced chemokine production by KU812 cells was significantly modulated by siRNA knockdown of RIG-I and PKR, in a negative and positive manner, respectively. Pretreatment of fresh KU812 cells with supernatants from dengue virus-infected mast cells provided protection from subsequent infection with dengue virus in a type I interferon-dependent manner. These findings support a role for tissue-resident mast cells in the early detection of antibody-enhanced dengue virus infection via RNA sensors, the protection of neighbouring cells through interferon production and the potential recruitment of

  11. Evaluation of the diagnostic accuracy of a new dengue IgA capture assay (Platelia Dengue IgA Capture, Bio-Rad for dengue infection detection.

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    Sophie De Decker

    2015-03-01

    Full Text Available Considering the short lifetime of IgA antibodies in serum and the key advantages of antibody detection ELISAs in terms of sensitivity and specificity, Bio-Rad has just developed a new ELISA test based on the detection of specific anti-dengue IgA. This study has been carried out to assess the performance of this Platelia Dengue IgA Capture assay for dengue infection detection. A total of 184 well-characterized samples provided by the French Guiana NRC sera collection (Laboratory of Virology, Institut Pasteur in French Guiana were selected among samples collected between 2002 and 2013 from patients exhibiting a dengue-like syndrome. A first group included 134 sera from confirmed dengue-infected patients, and a second included 50 sera from non-dengue infected patients, all collected between day 3 and day 15 after the onset of fever. Dengue infection diagnoses were all confirmed using reference assays by direct virological identification using RT-PCR or virus culture on acute sera samples or on paired acute-phase sera samples of selected convalescent sera. This study revealed: i a good overall sensitivity and specificity of the IgA index test, i.e., 93% and 88% respectively, indicating its good correlation to acute dengue diagnosis; and ii a good concordance with the Panbio IgM capture ELISA. Because of the shorter persistence of dengue virus-specific IgA than IgM, these results underlined the relevance of this new test, which could significantly improve dengue diagnosis accuracy, especially in countries where dengue virus is (hyper- endemic. It would allow for additional refinement of dengue diagnostic strategy.

  12. Evaluation of the diagnostic accuracy of a new dengue IgA capture assay (Platelia Dengue IgA Capture, Bio-Rad) for dengue infection detection.

    Science.gov (United States)

    De Decker, Sophie; Vray, Muriel; Sistek, Viridiana; Labeau, Bhety; Enfissi, Antoine; Rousset, Dominique; Matheus, Séverine

    2015-03-01

    Considering the short lifetime of IgA antibodies in serum and the key advantages of antibody detection ELISAs in terms of sensitivity and specificity, Bio-Rad has just developed a new ELISA test based on the detection of specific anti-dengue IgA. This study has been carried out to assess the performance of this Platelia Dengue IgA Capture assay for dengue infection detection. A total of 184 well-characterized samples provided by the French Guiana NRC sera collection (Laboratory of Virology, Institut Pasteur in French Guiana) were selected among samples collected between 2002 and 2013 from patients exhibiting a dengue-like syndrome. A first group included 134 sera from confirmed dengue-infected patients, and a second included 50 sera from non-dengue infected patients, all collected between day 3 and day 15 after the onset of fever. Dengue infection diagnoses were all confirmed using reference assays by direct virological identification using RT-PCR or virus culture on acute sera samples or on paired acute-phase sera samples of selected convalescent sera. This study revealed: i) a good overall sensitivity and specificity of the IgA index test, i.e., 93% and 88% respectively, indicating its good correlation to acute dengue diagnosis; and ii) a good concordance with the Panbio IgM capture ELISA. Because of the shorter persistence of dengue virus-specific IgA than IgM, these results underlined the relevance of this new test, which could significantly improve dengue diagnosis accuracy, especially in countries where dengue virus is (hyper-) endemic. It would allow for additional refinement of dengue diagnostic strategy.

  13. Formation of infectious dengue virus-antibody immune complex in vivo in marmosets (Callithrix jacchus) after passive transfer of anti-dengue virus monoclonal antibodies and infection with dengue virus.

    Science.gov (United States)

    Moi, Meng Ling; Ami, Yasushi; Shirai, Kenji; Lim, Chang-Kweng; Suzaki, Yuriko; Saito, Yuka; Kitaura, Kazutaka; Saijo, Masayuki; Suzuki, Ryuji; Kurane, Ichiro; Takasaki, Tomohiko

    2015-02-01

    Infection with a dengue virus (DENV) serotype induces cross-reactive, weakly neutralizing antibodies to different dengue serotypes. It has been postulated that cross-reactive antibodies form a virus-antibody immune complex and enhance DENV infection of Fc gamma receptor (FcγR)-bearing cells. We determined whether infectious DENV-antibody immune complex is formed in vivo in marmosets after passive transfer of DENV-specific monoclonal antibody (mAb) and DENV inoculation and whether infectious DENV-antibody immune complex is detectable using FcγR-expressing cells. Marmosets showed that DENV-antibody immune complex was exclusively infectious to FcγR-expressing cells on days 2, 4, and 7 after passive transfer of each of the mAbs (mAb 4G2 and mAb 6B6C) and DENV inoculation. Although DENV-antibody immune complex was detected, contribution of the passively transferred antibody to overall viremia levels was limited in this study. The results indicate that DENV cross-reactive antibodies form DENV-antibody immune complex in vivo, which is infectious to FcγR-bearing cells but not FcγR-negative cells.

  14. High content screening of a kinase-focused library reveals compounds broadly-active against dengue viruses.

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    Deu John M Cruz

    Full Text Available Dengue virus is a mosquito-borne flavivirus that has a large impact in global health. It is considered as one of the medically important arboviruses, and developing a preventive or therapeutic solution remains a top priority in the medical and scientific community. Drug discovery programs for potential dengue antivirals have increased dramatically over the last decade, largely in part to the introduction of high-throughput assays. In this study, we have developed an image-based dengue high-throughput/high-content assay (HT/HCA using an innovative computer vision approach to screen a kinase-focused library for anti-dengue compounds. Using this dengue HT/HCA, we identified a group of compounds with a 4-(1-aminoethyl-N-methylthiazol-2-amine as a common core structure that inhibits dengue viral infection in a human liver-derived cell line (Huh-7.5 cells. Compounds CND1201, CND1203 and CND1243 exhibited strong antiviral activities against all four dengue serotypes. Plaque reduction and time-of-addition assays suggests that these compounds interfere with the late stage of viral infection cycle. These findings demonstrate that our image-based dengue HT/HCA is a reliable tool that can be used to screen various chemical libraries for potential dengue antiviral candidates.

  15. Exantema hemorrágico por virus dengue inducido por ácido acetil-salicílico Haemorrhagic exanthema due to dengue virus induced by acetylsalicylic acid

    OpenAIRE

    Valerio, L.; X. de Balanzó; Jiménez, O.; M. L. Pedro-Botet

    2006-01-01

    El dengue, enfermedad infecciosa vírica propia de los climas tropicales, se considera una patología reemergente que ha dado lugar a graves epidemias en la última década. En la expansión del virus y de su mosquito vector se barajan factores relacionados con la alteración humana del medio, con la rapidez en el tránsito de mercancias y personas y debidos al cambio climático. Como reflejo de ello, se asiste a un aumento de casos importados que, al ser una enfermedad con periodo de incubación cort...

  16. Characteristics of Mild Dengue Virus Infection in Thai Children

    Science.gov (United States)

    2013-12-01

    Timothy P. Endy, and Alan L. Rothman Department of Virology, Armed Forces Research Institute of Medical Sciences, Bangkok , Thailand; University of...Virology, U.S. Army Medical Component, Armed Forces Research Institute of Medical Sciences, Bangkok , Thailand, APO, AP, USA 96546. E-mail: yooni...confidence interval; NS = not significant. 1084 YOON AND OTHERS population , mild dengue illness accounted for most symptom- atic DENV infections across all

  17. Dengue fever causing febrile neutropenia in children with acute lymphoblastic leukemia: an unknown entity.

    Science.gov (United States)

    Ramzan, Mohammed; Yadav, Satya Prakash; Dinand, Veronique; Sachdeva, Anupam

    2013-06-01

    Dengue fever is endemic in many parts of the world but it has not been described as a cause of febrile neutropenia. We describe here clinical features, laboratory values and outcome in 10 children with acute lymphoblastic leukemia (ALL) and with dengue fever as a cause of febrile neutropenia. These data are compared to an age-matched control population of 22 children with proven dengue infection without ALL. Except for fever in all patients and plethoric face in one patient, typical symptoms of dengue such as abdominal pain, myalgias, and headaches, were absent. Mean duration of hospital stay was 6.3±2.0 days in ALL patients vs. 5.0±2.0 in controls (p=0.096). Median platelet count was 13,000/cmm (range 1000-28,000) in cases vs. 31,500 (range 13,000-150,000) in controls (p=0.018). Mean time for recovery for platelet was 6.0±1.3days in ALL patients vs. 2.5±0.9days in controls (pfebrile neutropenia although typical symptoms may be lacking. Platelet recovery may be significantly delayed.

  18. Rare occurrence of natural transovarial transmission of dengue virus and elimination of infected foci as a possible intervention method.

    Science.gov (United States)

    Angel, Annette; Angel, Bennet; Joshi, Vinod

    2016-03-01

    Transovarial transmission of dengue virus has been studied in 33 districts of Rajasthan, India. Small proportion (1.09%) of breeding containers positive for the virus and their elimination has been demonstrated as a possible intervention method of disease control. Dengue virus was isolated from individual mosquitoes employing Indirect Fluorescence Antibody Test and Reverse Transcriptase Polymerase Chain Reaction. Out of 1,30,525 containers examined only 1432(1.09%) showed transovarially transmitted virus activity. Elimination of larvae from all the 1432 virus positive containers resulted in substantial control over prospective transmission of dengue. The study highlights rarity of transovarial transmission under natural conditions and sensitizes whether elimination of vertically infected foci could be used as a new intervention method.

  19. Development of a multiplex real-time RT-PCR assay for simultaneous detection of dengue and chikungunya viruses.

    Science.gov (United States)

    Cecilia, D; Kakade, M; Alagarasu, K; Patil, J; Salunke, A; Parashar, D; Shah, P S

    2015-01-01

    Dengue and chikungunya viruses co-circulate and cause infections that start with similar symptoms but progress to radically different outcomes. Therefore, an early diagnostic test that can differentiate between the two is needed. A single-step multiplex real-time RT-PCR assay was developed that can simultaneously detect and quantitate RNA of all dengue virus (DENV) serotypes and chikungunya virus (CHIKV). The sensitivity was 100 % for DENV and 95.8 % for CHIKV, whilst the specificity was 100 % for both viruses when compared with conventional RT-PCR. The detection limit ranged from 1 to 50 plaque-forming units. The assay was successfully used for differential diagnosis of dengue and chikungunya in Pune, where the viruses co-circulate.

  20. Antiviral activities of extracts and phenolic components of two Spondias species against dengue virus

    Directory of Open Access Journals (Sweden)

    Ara Silva

    2011-01-01

    Full Text Available In recent years, the search for natural plant products to fight viral diseases has been increasing. In this work, two Spondias species, namely S. mombin and S. tuberosa, found in Ceará state (Brazil, and their main phenolic components were evaluated against dengue virus. In vitro antiviral tests were performed against type-2 dengue virus by the MTT method and standard cytopathic effect reduction assay in C6/36 cells. Cytotoxicity was also evaluated by MTT. The presence of phenolic compounds quercetin, rutin, and ellagic acid in plant extracts was characterized by HPLC analysis. Both Spondias species extracts and components were nontoxic to the cells whereas rutin and quercetin displayed relevant antiviral activity with IC50 of 362.68 µg/mL and 500 µg/mL, respectively.

  1. Comparative Evaluation of Permissiveness to Dengue Virus Serotype 2 Infection in Primary Rodent Macrophages

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    Jeanette Prada-Arismendy

    2012-01-01

    Full Text Available Infection with dengue virus presents a broad clinical spectrum, which can range from asymptomatic cases to severe cases that are characterised by haemorrhagic syndrome and/or shock. The reason for such variability remains unknown. This work evaluated the in vitro permissiveness of mouse, rat, hamster and guinea pig macrophages to infection by dengue virus 2 (DENV2. The results established that macrophages derived from the BALB/c mouse strain showed higher permissiveness to DENV2 infection than macrophages from other rodent species, although all rodent species studied had the C820T mutation in the oligoadenylate synthetase 1b gene, indicating no relationship to the different in vitro susceptibilities of mouse cells at this locus. Other molecular mechanisms related to flavivirus susceptibility remain to be explored.

  2. Study on the determinants of suckling mice neurovirulence of dengue 2 virus

    Institute of Scientific and Technical Information of China (English)

    赵卫; 范宝昌; 胡志君; 陈水平; 王鹏程; 苑锡同; 李晓萸; 于曼; 秦鄂德; 杨佩英

    2003-01-01

    pDVWS501 was a genomic-length cDNA clone of dengue 2 virus, through which infectious virus (MON501) could be rescued. MON501 was neurovirulent in mice, whose E residues 62 and 203 were Lys and Asn, respectively. Two genomic-length cDNA clones (TB62 and TB203) were constructed by pointed mutation of pDVWS501 with OL-PCR, E62 of TB62 and E203 of TB203 were converted to Glu and Asp, respectively. RNA transcripts of pDVWS501, TB62 and TB203 were produced in vitro and electroporated into BHK-21 cells. The cultures were collected after 7 days and used as inoculum to infect C6/36 cells. The existence of rescued dengue viruses in the culture was proved by RT-PCR, and the typical cytopathic effect (CPE) of C6/36 caused by dengue virus emerged after 2-5 days' inoculation. Sequence analysis further confirmed the existence of recovered and recombinant DEN2 viruses, whose 5′ termini had an additional non-virus nucleotides "G", while the 3′ terminal sequences remained the same as natural. The neurovirulence of three viruses was evaluated in 1-day-old mice by the intracerebral route with 105-102 TCID50. Compared with MON501 group, the number of infected mice with the signs of encephalitis in HFT62 and HFT203 groups was less, and the surviving time was longer. The properties of these mutants demonstrated that E62 and E203 are determinants of suckling mice neurovirulence.

  3. Dengue encephalitis-A rare manifestation of dengue fever

    OpenAIRE

    Madi, Deepak; Achappa, Basavaprabhu; Ramapuram, John T; Chowta, Nityananda; Laxman, Mridula; Mahalingam, Soundarya

    2014-01-01

    The clinical spectrum of dengue fever ranges from asymptomatic infection to dengue shock syndrome. Dengue is classically considered a non-neurotropic virus. Neurological complications are not commonly seen in dengue. The neurological manifestations seen in dengue are encephalitis, meningitis, encephalopathy, stroke and Guillain-Barré syndrome. Dengue encephalitis is a rare disease. We report an interesting case of dengue encephalitis from Southern India. A 49-year-old gentleman presented with...

  4. Correlation between dengue-specific neutralizing antibodies and serum avidity in primary and secondary dengue virus 3 natural infections in humans.

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    Andreas Puschnik

    Full Text Available Although heterotypic secondary infection with dengue virus (DENV is associated with severe disease, the majority of secondary infections are mild or asymptomatic. The mechanisms of antibody-mediated protection are poorly understood. In 2010, 108 DENV3-positive cases were enrolled in a pediatric hospital-based study in Managua, Nicaragua, with 61 primary and 47 secondary infections. We analyzed DENV-specific neutralization titers (NT50, IgM and IgG avidity, and antibody titer in serum samples collected during acute and convalescent phases and 3, 6, and 18 months post-infection. NT50 titers peaked at convalescence and decreased thereafter. IgG avidity to DENV3 significantly increased between convalescent and 3-month time-points in primary DENV infections and between the acute and convalescent phase in secondary DENV infections. While avidity to DENV2, a likely previous infecting serotype, was initially higher than avidity to DENV3 in secondary DENV infections, the opposite relation was observed 3-18 months post-infection. We found significant correlations between IgM avidity and NT50 in acute primary cases and between IgG avidity and NT50 in secondary DENV infections. In summary, our findings indicate that IgM antibodies likely play a role in early control of DENV infections. IgG serum avidity to DENV, analyzed for the first time in longitudinal samples, switches from targeting mainly cross-reactive serotype(s to the current infecting serotype over time. Finally, serum avidity correlates with neutralization capacity.

  5. Dengue and other common causes of acute febrile illness in Asia: an active surveillance study in children.

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    Maria Rosario Capeding

    Full Text Available BACKGROUND: Common causes of acute febrile illness in tropical countries have similar symptoms, which often mimic those of dengue. Accurate clinical diagnosis can be difficult without laboratory confirmation and disease burden is generally under-reported. Accurate, population-based, laboratory-confirmed incidence data on dengue and other causes of acute fever in dengue-endemic Asian countries are needed. METHODS AND PRINCIPAL FINDINGS: This prospective, multicenter, active fever surveillance, cohort study was conducted in selected centers in Indonesia, Malaysia, Philippines, Thailand and Vietnam to determine the incidence density of acute febrile episodes (≥ 38 °C for ≥ 2 days in 1,500 healthy children aged 2-14 years, followed for a mean 237 days. Causes of fever were assessed by testing acute and convalescent sera from febrile participants for dengue, chikungunya, hepatitis A, influenza A, leptospirosis, rickettsia, and Salmonella Typhi. Overall, 289 participants had acute fever, an incidence density of 33.6 per 100 person-years (95% CI: 30.0; 37.8; 57% were IgM-positive for at least one of these diseases. The most common causes of fever by IgM ELISA were chikungunya (in 35.0% of in febrile participants and S. Typhi (in 29.4%. The overall incidence density of dengue per 100 person-years was 3.4 by nonstructural protein 1 (NS1 antigen positivity (95% CI: 2.4; 4.8 and 7.3 (95% CI: 5.7; 9.2 by serology. Dengue was diagnosed in 11.4% (95% CI: 8.0; 15.7 and 23.9% (95% CI: 19.1; 29.2 of febrile participants by NS1 positivity and serology, respectively. Of the febrile episodes not clinically diagnosed as dengue, 5.3% were dengue-positive by NS1 antigen testing and 16.0% were dengue-positive by serology. CONCLUSIONS: During the study period, the most common identified causes of pediatric acute febrile illness among the seven tested for were chikungunya, S. Typhi and dengue. Not all dengue cases were clinically diagnosed; laboratory confirmation

  6. Envelope gene evolution analysis on type 1, 2, 3 dengue virus in Guangzhou in 2010%广州市2010年1、2、3型登革病毒E基因进化分析

    Institute of Scientific and Technical Information of China (English)

    白志军; 和鹏; 狄飚; 鲁恩洁; 罗雷; 杨智聪; 王鸣; 王玉林

    2012-01-01

    目的 测定广州市2010年1、2、3型登革病毒的E基因序列,探讨其来源及基因型.方法 收集广州市2010年85例登革热患者急性期血清,用C6/36细胞培养分离登革病毒,RT-PCR法扩增全长E基因,测定序列并绘制系统发育树,结合流行病学资料进行信息学分析.结果 85份血清标本中分离到1型和3型登革病毒株各6株,2型登革病毒2株,测序获得E基因序列.进化分析发现,1型和3型登革病毒分别来自不同的亚型,即亚洲型和南太平洋型,印度次大陆型和东南亚/南太平洋型;2型登革病毒来自马来西亚/印度次大陆型.结论 推测广州市2010年2型登革病毒为输入性.1型和3型登革病毒中各有4株为输入性,余各2株广州本地病例毒株尚须从蚊媒介来进一步证实其来源.%Objective To analyze the Envelope (E) gene of type 1,2,3 dengue virus isolated from Guangzhou in 2010, and to investigate the infection source and virus genotypes.Methods Eighty-five serum samples were collected from 85 patients in acute phase of dengue fever.Dengue virus was cultured and isolated by C6/36 cells.The whole length of E gene was amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) and then sequenced.The phylogenetic tree was drawn by neighbor-joining method.The bioinformatics analysis was performed by combining the phylogenetic information and the epidemiologic data.Results Six strains of type 1 dengue virus,two strains of type 2 dengue virus and six strains of type 3 dengue virus were isolated from 85 samples.The E gene sequence of these strains was obtained by sequencing.The phylogenetic analysis showed that type 1 and 3 dengue virus belonged to two genotypes (Asian and South Pacific ocean,India subcontinent and Southeast Asia/South Pacific ocean,respectively),and type 2 dengue virus belonged to one genotype (Malaysia/India subcontinent).Conclusion It's presumed that all strains of type 2 dengue virus are imported

  7. Primary dengue virus infections induce differential cytokine production in Mexican patients

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    Sergio Isaac de la Cruz Hernández

    2016-03-01

    Full Text Available Severe dengue pathogenesis is not fully understood, but high levels of proinflammatory cytokines have been associated with dengue disease severity. In this study, the cytokine levels in 171 sera from Mexican patients with primary dengue fever (DF and dengue haemorrhagic fever (DHF from dengue virus (DENV 1 (n = 116 or 2 (n = 55 were compared. DF and DHF were defined according to the patient’s clinical condition, the primary infections as indicated by IgG enzymatic immunoassay negative results, and the infecting serotype as assessed by real-time reverse transcription-polymerase chain reaction. Samples were analysed for circulating levels of interleukin (IL-12p70, interferon (IFN-γ, tumour necrosis factor (TNF-α, IL-6, and IL-8 using a commercial cytometric bead array. Significantly higher IFN-γ levels were found in patients with DHF than those with DF. However, significantly higher IL-12p70, TNF-α, and IL-6 levels were associated with DHF only in patients who were infected with DENV2 but not with DENV1. Moreover, patients with DF who were infected with DENV1 showed higher levels of IL-12p70, TNF-α, and IL-6 than patients with DHF early after-fever onset. The IL-8 levels were similar in all cases regardless of the clinical condition or infection serotype. These results suggest that the association between high proinflammatory cytokine levels and dengue disease severity does not always stand, and it once again highlights the complex nature of DHF pathogenesis.

  8. Intracerebral infection with dengue-3 virus induces meningoencephalitis and behavioral changes that precede lethality in mice

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    Campos Marco A

    2011-03-01

    Full Text Available Abstract Background Dengue, one of the most important arboviral diseases of humans, may cause severe systemic disease. Although dengue virus (DENV has been considered to be a non-neurotropic virus, dengue infection has been associated recently with a series of neurological syndromes, including encephalitis. In this work, we evaluated behavioral changes and inflammatory parameters in C57BL/6 mice infected with non-adapted dengue virus 3 (DENV-3 genotype I. Methods C57BL/6 mice received 4 × 103 PFU of DENV-3 by an intracranial route. We evaluated the trafficking of leukocytes in brain microvasculature using intravital microscopy, and evaluated chemokine and cytokine profiling by an ELISA test at 3 and 6 days post infection (p.i.. Furthermore, we determined myeloperoxidase activity and immune cell populations, and also performed histopathological analysis and immunostaining for the virus in brain tissue. Results All animals developed signs of encephalitis and died by day 8 p.i. Motor behavior and muscle tone and strength parameters declined at day 7 p.i. We observed increased leukocyte rolling and adhesion in brain microvasculature of infected mice at days 3 and 6 p.i. The infection was followed by significant increases in IFN-γ, TNF-α, CCL2, CCL5, CXCL1, and CXCL2. Histological analysis showed evidence of meningoencephalitis and reactive gliosis. Increased numbers of neutrophils, CD4+ and CD8+ T cells were detected in brain of infected animals, notably at day 6 p.i. Cells immunoreactive for anti-NS-3 were visualized throughout the brain. Conclusion Intracerebral infection with non-adapted DENV-3 induces encephalitis and behavioral changes that precede lethality in mice.

  9. Evolving RNA Virus Pandemics: HIV, HCV, Ebola, Dengue, Chikunguya, and now Zika!

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    Barreiro, Pablo

    2016-01-01

    The Zika virus (ZIKV), a flavivirus related to yellow fever, dengue, and West Nile, originated in the Zika forest in Uganda and was discovered in a rhesus monkey in 1947. The disease now has "explosive" pandemic potential, with outbreaks in Africa, Southeast Asia, the Pacific Islands, and the Americas. To date, the CDC has issued travel alerts for at least 30 countries and territories in Latin America, the Caribbean, Polynesia, and Cape Verde in Africa.

  10. Dengue-specific CD8+ T cells have both protective and pathogenic roles in dengue virus infection.

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    An, Jing; Zhou, De-Shan; Zhang, Jun-Lei; Morida, Hatue; Wang, Jia-Li; Yasui, Kotaro

    2004-09-01

    To analyze roles of memory T cells in the pathogenesis of dengue (DEN) virus infection, a DEN virus-specific CD8+ cell clone (2D42 cell) was employed to investigate its in vivo function after DEN virus infection using an animal model. HepG2 grafted severe combined immunodeficient (HepG2-grafted SCID) mice were divided into three groups--group A: HepG2-grafted SCID mice were inoculated intraperitoneally (ip) with 2D42 cells and then ip-infected with DEN virus type 2 (DEN-2); group B: HepG2-grafted SCID mice were inoculated with naive mouse thymocytes (NMT) and then ip-infected with DEN-2; group C: HepG2-grafted SCID mice were ip-infected with DEN-2 alone. Eighty percentage of group A mice died at average day 12.8 post-infection (p.i.) and 20% of them recovered from the disease after showing clinical signs and survived more than 3 months. They showed severe manifestations including dramatically decreased platelet count, decreased hematocrit, anemia, viremia and high frequency of histopathological changes in several organs. All of group B mice also showed the above severe clinical signs. One hundred percentage mortality rate was noted in these mice and death occurred at average day 10.8 p.i., which was the earliest among three groups. Although the mice from group C showed 100% mortality rate and similar clinical signs, death observed in these mice occurred at average day 17.4 p.i. and the manifestations were slight and developed slowly. Our results suggested both protective and pathogenic roles for DEN-specific CD8+ T cell in DEN virus infection, whereas NMT did not provided any protection.

  11. Prevalence and characteristics of dengue and chikungunya infections among acute febrile patients in Nong Khai Province, Thailand.

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    Lertanekawattana, Sujet; Anantapreecha, Surapee; Jiraphongsa, Chuleeporn; Duan-ngern, Pawinee; Potjalongsin, Sathit; Wiittayabamrung, Wisanu; Daroon, Pamol; Techolarn, Meta

    2013-09-01

    We conducted a cross sectional study at three hospitals of Nong Khai Province, Thailand to determine the prevalence and characteristics of dengue and chikungunya infection among patients who sought care. The study population was acute febrile patients who visited these hospitals during 1 August -31 October, 2010 who were aged 2-60 years and had clinical symptoms compatible with the case definition. Dengue and chikungunya cases were confirmed by an ELISA IgM titer or RT-PCR. We also reviewed surveillance data of dengue and chikungunya infections from 2003-2009. Of the 200 participants recruited into the study, 103 patients (51.5%) were confirmed to have acute dengue infection; dengue serotype 2 was the most prevalence serotype. The ages of confirmed dengue cases ranged from 2-37 years old. The distribution of cases showed that dengue morbidity tended to be clustered in adjacent areas, particularly in Mueang District. Only a small proportion of the patients uses mosquito repellant and had screens on their windows. One patient (0.5%) had laboratory confirmed chikungunya infection. She was from Rattanawapi District, an area where no chikungunya had been reported before. Since the disease varies by age and geographic location, increased awareness of health care workers and public health officers about the diseases in the area is needed for early detection of cases and to promote early prevention and control measures.

  12. The vector competence of colonized Aedes (Stegomyia) katherinensis for dengue-2 virus.

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    Leake, C J

    1984-01-01

    Colonized Aedes (Stegomyia) katherinensis mosquitoes from Australia were infected with the PR-159 strain of dengue-2 virus using a membrane feeding technique and by intrathoracic inoculation. Virus replication to low levels was detected when mosquitoes infected by both routes were assayed using the virus-sensitive Ae. pseudoscutellaris (LSTM-AP-61) mosquito cell line in a microculture system. Analysis by indirect immunofluorescence revealed the expected 100% infection rates in inoculated mosquitoes compared with only 45% in orally infected mosquitoes. Few of the orally infected mosquitoes showed any viral antigen associated with the head and no virus transmission was detected. Preliminary studies also demonstrated that Ae. (S.) katherinesis was refractory to oral infection with Japanese encephalitis virus but was readily infected by intrathoracic inoculation. On the basis of this data, it is concluded that there is a high threshold of infection in this mosquito and that it is unlikely that Ae. (S.) katherinensis could be important as a vector of dengue-2 virus in Australia.

  13. The distribution of synonymous codon choice in the translation initiation region of dengue virus.

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    Jian-hua Zhou

    Full Text Available Dengue is the most common arthropod-borne viral (Arboviral illness in humans. The genetic features concerning the codon usage of dengue virus (DENV were analyzed by the relative synonymous codon usage, the effective number of codons and the codon adaptation index. The evolutionary distance between DENV and the natural hosts (Homo sapiens, Pan troglodytes, Aedes albopictus and Aedes aegypti was estimated by a novel formula. Finally, the synonymous codon usage preference for the translation initiation region of this virus was also analyzed. The result indicates that the general trend of the 59 synonymous codon usage of the four genotypes of DENV are similar to each other, and this pattern has no link with the geographic distribution of the virus. The effect of codon usage pattern of Aedes albopictus and Aedes aegypti on the formation of codon usage of DENV is stronger than that of the two primates. Turning to the codon usage preference of the translation initiation region of this virus, some codons pairing to low tRNA copy numbers in the two primates have a stronger tendency to exist in the translation initiation region than those in the open reading frame of DENV. Although DENV, like other RNA viruses, has a high mutation to adapt its hosts, the regulatory features about the synonymous codon usage have been 'branded' on the translation initiation region of this virus in order to hijack the translational mechanisms of the hosts.

  14. Molecular epidemiology of dengue viruses in southern China from 1978 to 2006

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    Liu Jinhua

    2011-06-01

    Full Text Available Abstract To investigate molecular epidemiology of dengue viruses (DENV in southern China, a total of 14 dengue isolates were collected in southern China during each epidemic year between 1978 and 2006 and their full-length genome sequences were obtained by using RT-PCR method. The E gene sequences from additional 6 dengue fever patients in Guangzhou in 2006 were also obtained by using RT-PCR method. Combined with DENVs sequences published in GenBank, phylogenetic analysis and recombination analysis were performed. One hundred and twenty-five E gene sequences and 60 complete genome sequences published in the GenBank were also involved. Phylogenetic analysis showed that there was a wide genetic diversity of DENVs isolated in southern China. DENV-1 strains exist in almost all of the clades of genotype I and IV except the Asia 1 clade of genotype I; DENV-2 stains are grouped into four of the five genotypes except American genotype. DENV-4 strains are grouped into 2 genotypes (I and II. Phylogenetic analysis also showed that all DENV-4 isolates and two DENV-2 isolates were closely related to the prior isolates from neighboring Southeast Asia countries. The DENV-1 strain isolated during the 2006 epidemic is highly homologous to the strains isolated during the 2001 epidemic. Recombination analysis showed no inter-serotype recombination, but 22 intra-serotype recombination events were found across the 32 complete genomes of all Chinese isolates. The study suggested that dengue fever epidemic in Southern China over the past 30 years presented two important modes, 1 imported-cases-induced endemic prevalence; 2 endogenous epidemic outbreak with natural epidemic focus. Recombination may play an important role in dengue virus evolution and adaptation.

  15. Dengue viruses binding proteins from Aedes aegypti and Aedes polynesiensis salivary glands

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    Cao-Lormeau Van-Mai

    2009-03-01

    Full Text Available Abstract Dengue virus (DENV, the etiological agent of dengue fever, is transmitted to the human host during blood uptake by an infective mosquito. Infection of vector salivary glands and further injection of infectious saliva into the human host are key events of the DENV transmission cycle. However, the molecular mechanisms of DENV entry into the mosquito salivary glands have not been clearly identified. Otherwise, although it was demonstrated for other vector-transmitted pathogens that insect salivary components may interact with host immune agents and impact the establishment of infection, the role of mosquito saliva on DENV infection in human has been only poorly documented. To identify salivary gland molecules which might interact with DENV at these key steps of transmission cycle, we investigated the presence of proteins able to bind DENV in salivary gland extracts (SGE from two mosquito species. Using virus overlay protein binding assay, we detected several proteins able to bind DENV in SGE from Aedes aegypti (L. and Aedes polynesiensis (Marks. The present findings pave the way for the identification of proteins mediating DENV attachment or entry into mosquito salivary glands, and of saliva-secreted proteins those might be bound to the virus at the earliest step of human infection. The present findings might contribute to the identification of new targets for anti-dengue strategies.

  16. Genome sequence analysis of dengue virus 1 isolated in Key West, Florida.

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    Shin, Dongyoung; Richards, Stephanie L; Alto, Barry W; Bettinardi, David J; Smartt, Chelsea T

    2013-01-01

    Dengue virus (DENV) is transmitted to humans through the bite of mosquitoes. In November 2010, a dengue outbreak was reported in Monroe County in southern Florida (FL), including greater than 20 confirmed human cases. The virus collected from the human cases was verified as DENV serotype 1 (DENV-1) and one isolate was provided for sequence analysis. RNA was extracted from the DENV-1 isolate and was used in reverse transcription polymerase chain reaction (RT-PCR) to amplify PCR fragments to sequence. Nucleic acid primers were designed to generate overlapping PCR fragments that covered the entire genome. The DENV-1 isolate found in Key West (KW), FL was sequenced for whole genome characterization. Sequence assembly, Genbank searches, and recombination analyses were performed to verify the identity of the genome sequences and to determine percent similarity to known DENV-1 sequences. We show that the KW DENV-1 strain is 99% identical to Nicaraguan and Mexican DENV-1 strains. Phylogenetic and recombination analyses suggest that the DENV-1 isolated in KW originated from Nicaragua (NI) and the KW strain may circulate in KW. Also, recombination analysis results detected recombination events in the KW strain compared to DENV-1 strains from Puerto Rico. We evaluate the relative growth of KW strain of DENV-1 compared to other dengue viruses to determine whether the underlying genetics of the strain is associated with a replicative advantage, an important consideration since local transmission of DENV may result because domestic tourism can spread DENVs.

  17. Genome sequence analysis of dengue virus 1 isolated in Key West, Florida.

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    Dongyoung Shin

    Full Text Available Dengue virus (DENV is transmitted to humans through the bite of mosquitoes. In November 2010, a dengue outbreak was reported in Monroe County in southern Florida (FL, including greater than 20 confirmed human cases. The virus collected from the human cases was verified as DENV serotype 1 (DENV-1 and one isolate was provided for sequence analysis. RNA was extracted from the DENV-1 isolate and was used in reverse transcription polymerase chain reaction (RT-PCR to amplify PCR fragments to sequence. Nucleic acid primers were designed to generate overlapping PCR fragments that covered the entire genome. The DENV-1 isolate found in Key West (KW, FL was sequenced for whole genome characterization. Sequence assembly, Genbank searches, and recombination analyses were performed to verify the identity of the genome sequences and to determine percent similarity to known DENV-1 sequences. We show that the KW DENV-1 strain is 99% identical to Nicaraguan and Mexican DENV-1 strains. Phylogenetic and recombination analyses suggest that the DENV-1 isolated in KW originated from Nicaragua (NI and the KW strain may circulate in KW. Also, recombination analysis results detected recombination events in the KW strain compared to DENV-1 strains from Puerto Rico. We evaluate the relative growth of KW strain of DENV-1 compared to other dengue viruses to determine whether the underlying genetics of the strain is associated with a replicative advantage, an important consideration since local transmission of DENV may result because domestic tourism can spread DENVs.

  18. Novel dengue virus NS2B/NS3 protease inhibitors.

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    Wu, Hongmei; Bock, Stefanie; Snitko, Mariya; Berger, Thilo; Weidner, Thomas; Holloway, Steven; Kanitz, Manuel; Diederich, Wibke E; Steuber, Holger; Walter, Christof; Hofmann, Daniela; Weißbrich, Benedikt; Spannaus, Ralf; Acosta, Eliana G; Bartenschlager, Ralf; Engels, Bernd; Schirmeister, Tanja; Bodem, Jochen

    2015-02-01

    Dengue fever is a severe, widespread, and neglected disease with more than 2 million diagnosed infections per year. The dengue virus NS2B/NS3 protease (PR) represents a prime target for rational drug design. At the moment, there are no clinical PR inhibitors (PIs) available. We have identified diaryl (thio)ethers as candidates for a novel class of PIs. Here, we report the selective and noncompetitive inhibition of the serotype 2 and 3 dengue virus PR in vitro and in cells by benzothiazole derivatives exhibiting 50% inhibitory concentrations (IC50s) in the low-micromolar range. Inhibition of replication of DENV serotypes 1 to 3 was specific, since all substances influenced neither hepatitis C virus (HCV) nor HIV-1 replication. Molecular docking suggests binding at a specific allosteric binding site. In addition to the in vitro assays, a cell-based PR assay was developed to test these substances in a replication-independent way. The new compounds inhibited the DENV PR with IC50s in the low-micromolar or submicromolar range in cells. Furthermore, these novel PIs inhibit viral replication at submicromolar concentrations.

  19. Respuesta neuroinmunológica en la encefalitis asociada al virus del dengue

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    Bárbara Padilla-Docal

    2013-12-01

    Full Text Available El virus del dengue es un virus ARN miembro de la familia Flaviviridae, la cual incluye, además, el de la fiebre amarilla, el del Nilo del Oeste y la encefalitis japonesa. Se realizó un estudio retrospectivo con tres pacientes diagnosticados de encefalitis asociada al dengue, en cuyas muestras de suero y líquido cefalorraquídeo se cuantificaron los niveles de las clases mayores de inmunoglobulinas por inmunodifusión radial y la manosa de unión a lectina, proteína de la vía de las lectinas del sistema del complemento por fluorometría. En el reibergrama se muestra la presencia de síntesis intratecal de las tres clases de inmunoglobulinas y ausencia de síntesis intratecal de lectina de unión a manosa. Existieron diferencias en cuanto al por ciento de síntesis intratecal de inmunoglobulinas, las cuales estuvieron relacionadas con el momento de la infección por el virus y la aparición de las manifestaciones neurológicas compatibles con una encefalitis. Este es el primer reporte de afectaciones neurológicas en pacientes cubanos con dengue. La respuesta inmune intratecal puede ser utilizada para el mejor conocimiento de la enfermedad y contribuir al desarrollo de posibles candidatos vacunales.

  20. Sensitivity and specificity of immunocytochemical assay for detection of Dengue virus 3 infection in mosquito

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    Dyah Widiastuti

    2012-07-01

    Full Text Available Latar belakang: Survei virologi pada nyamuk vektor dapat digunakan sebagai Sistem Kewaspadaan Dini untuk mencegah penularan Demam dengue di suatu daerah. Pemeriksaan laboratoris untuk deteksi virus Dengue pada nyamuk seperti isolasi virus, Polymerase Chain Reaction (PCR dan Direct Fluorescent-Antibody (DFA memerlukan keahlian yang tinggi, peralatan yang mahal dan waktu yang lama. Suatu metode berdasarkan imunositokimia menggunakan antibody monoclonal DSSE10 memiliki beberapa kelebihan. Tujuan penelitian ini untuk mengevaluasi sensitifitas dan spesifitas pemeriksaan imunositokimia dibandingkan metode Reverse Transcription-Polymerase Chain Reaction (RT-PCR untuk mendeteksi infeksi Virus Dengue 3. Metode: Penelitian eksperimental dilakukan di laboratorium Parasitologi Fakultas Kedokteran Universitas Gajah Mada (UGM pada bulan Mei 2009-Oktober 2010. Sebanyak 22 Ae. aegypti yang diinfeksi virus Dengue 3 digunakan sebagai  kelompok  infeksius dan  35  nyamuk  yang  tidak  diinfeksi  sebagai  kelompok  non infeksius.  Pemeriksaan imunositokimia  Streptavidin  Biotin Peroxidase  Complex  (SBPC  menggunakan  antibodi  monoklonal DSSE10 dilakukan pada sediaan head squash Ae .aegypti untuk mendeteksi antigen virus Dengue 3.  Pemeriksaan RT-PCR sebagai baku emas diaplikasikan pada toraks nyamuk.Hasil: Nilai Kappa menunjukkan kesepakatan yang baik antara dua orang pemeriksa (0,63. Imunositokimia mendeteksi antigen virus Dengue-3 dengan sensitivitas yang sama dengan RT-PCR (sensitivitas 100%. Namun spesifisitas IC lebih rendah dibanding RT-PCR (spesifisitas 91% karena beberapa hasil positif palsu muncul pada pemeriksaan ini. Kesimpulan: Metode IC memiliki nilai sensitivitas dan spesifisitas yang tinggi dibandingkan dengan metode RT-PCR. Metode IC ini dapat digunakan untuk surveilans virus Dengue pada nyamuk vektor. (Health Science Indones 2011;2:87-91.AbstractBackground: Virological  surveillance  provides  an

  1. IRAV (FLJ11286), an Interferon-Stimulated Gene with Antiviral Activity against Dengue Virus, Interacts with MOV10

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    Balinsky, Corey A.; Schmeisser, Hana; Wells, Alexandra I.; Ganesan, Sundar; Jin, Tengchuan; Singh, Kavita

    2016-01-01

    ABSTRACT Dengue virus (DENV) is a member of the genus Flavivirus and can cause severe febrile illness. Here, we show that FLJ11286, which we refer to as IRAV, is induced by DENV in an interferon-dependent manner, displays antiviral activity against DENV, and localizes to the DENV replication complex. IRAV is an RNA binding protein and localizes to cytoplasmic processing bodies (P bodies) in uninfected cells, where it interacts with the MOV10 RISC complex RNA helicase, suggesting a role for IRAV in the processing of viral RNA. After DENV infection, IRAV, along with MOV10 and Xrn1, localizes to the DENV replication complex and associates with DENV proteins. Depletion of IRAV or MOV10 results in an increase in viral RNA. These data serve to characterize an interferon-stimulated gene with antiviral activity against DENV, as well as to propose a mechanism of activity involving the processing of viral RNA. IMPORTANCE Dengue virus, a member of the family Flaviviridae, can result in a life-threatening illness and has a significant impact on global health. Dengue virus has been shown to be particularly sensitive to the effects of type I interferon; however, little is known about the mechanisms by which interferon-stimulated genes function to inhibit viral replication. A better understanding of the interferon-mediated antiviral response to dengue virus may aid in the development of novel therapeutics. Here, we examine the influence of the interferon-stimulated gene IRAV (FLJ11286) on dengue virus replication. We show that IRAV associates with P bodies in uninfected cells and with the dengue virus replication complex after infection. IRAV also interacts with MOV10, depletion of which is associated with increased viral replication. Our results provide insight into a newly identified antiviral gene, as well as broadening our understanding of the innate immune response to dengue virus infection. PMID:27974568

  2. The Risk of Dengue Virus Transmission in Dar es Salaam, Tanzania during an Epidemic Period of 2014.

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    Leonard E G Mboera

    2016-01-01

    Full Text Available In 2010, 2012, 2013 and 2014 dengue outbreaks have been reported in Dar es Salaam, Tanzania. However, there is no comprehensive data on the risk of transmission of dengue in the country. The objective of this study was to assess the risk of transmission of dengue in Dar es Salaam during the 2014 epidemic.This cross-sectional study was conducted in Dar es Salaam, Tanzania during the dengue outbreak of 2014. The study involved Ilala, Kinondoni and Temeke districts. Adult mosquitoes were collected using carbon dioxide-propane powered Mosquito Magnet Liberty Plus traps. In each household compound, water-holding containers were examined for mosquito larvae and pupae. Dengue virus infection of mosquitoes was determined using real-time reverse transcription polymerase chain reaction (qRT-PCR. Partial amplification and sequencing of dengue virus genome in infected mosquitoes was performed. A total of 1,000 adult mosquitoes were collected. Over half (59.9% of the adult mosquitoes were collected in Kinondoni. Aedes aegypti accounted for 17.2% of the mosquitoes of which 90.6% were from Kinondoni. Of a total of 796 houses inspected, 38.3% had water-holding containers in their premises. Kinondoni had the largest proportion of water-holding containers (57.7%, followed by Temeke (31.4% and Ilala (23.4%. The most common breeding containers for the Aedes mosquitoes were discarded plastic containers and tires. High Aedes infestation indices were observed for all districts and sites, with a house index of 18.1% in Ilala, 25.5% in Temeke and 35.3% in Kinondoni. The respective container indices were 77.4%, 65.2% and 80.2%. Of the reared larvae and pupae, 5,250 adult mosquitoes emerged, of which 61.9% were Ae. aegypti. Overall, 27 (8.18 of the 330 pools of Ae. aegypti were positive for dengue virus. On average, the overall maximum likelihood estimate (MLE indicates pooled infection rate of 8.49 per 1,000 mosquitoes (95%CI = 5.72-12.16. There was no significant

  3. Dengue virus infection elicits highly polarized CX3CR1+ cytotoxic CD4+ T cells associated with protective immunity.

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    Weiskopf, Daniela; Bangs, Derek J; Sidney, John; Kolla, Ravi V; De Silva, Aruna D; de Silva, Aravinda M; Crotty, Shane; Peters, Bjoern; Sette, Alessandro

    2015-08-04

    Dengue virus (DENV) is a rapidly spreading pathogen with unusual pathogenesis, and correlates of protection from severe dengue disease and vaccine efficacy have not yet been established. Although DENV-specific CD8(+) T-cell responses have been extensively studied, the breadth and specificity of CD4(+) T-cell responses remains to be defined. Here we define HLA-restricted CD4(+) T-cell epitopes resulting from natural infection with dengue virus in a hyperepidemic setting. Ex vivo flow-cytometric analysis of DENV-specific CD4(+) T cells revealed that the virus-specific cells were highly polarized, with a strong bias toward a CX3CR1(+) Eomesodermin(+) perforin(+) granzyme B(+) CD45RA(+) CD4 CTL phenotype. Importantly, these cells correlated with a protective HLA DR allele, and we demonstrate that these cells have direct ex vivo DENV-specific cytolytic activity. We speculate that cytotoxic dengue-specific CD4(+) T cells may play a role in the control of dengue infection in vivo, and this immune correlate may be a key target for dengue virus vaccine development.

  4. Early Detection and Serotyping of Dengue Viruses Clinical Isolates Using Reverse Transcription Polymerase Chain Reaction (RT-PCR 2 Primers

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    Abdul Rahman Siregar

    2015-11-01

    Full Text Available Recently several methods for confirming Dengue Virus have been developed involve virus isolation, detection of virus antigen, and nucleic acid using PCR. It has been reported that rapid detection method for confirming DHF by Multiplex RT-PCR had been successfully developed. It was more effective than the other methods with a high sensitivity and specivicity were 100% at the early phase (day 1-3. This study was designed to develop rapid detection and serotyping methods for Dengue Virus using RT-PCR 2 primers (Dcon and preM with annealing temperature was 57oC. The whole blood samples were collected from suspected dengue fever patients that had been confirmed with NS1 kit from R.S. Persahabatan DKI Jakarta and R.S. Prof. Dr. Sardjito DI Yogyakarta during Februari-August 2009. The PCR products showed that in 12 samples, 100 % were postitive with different pattern among the serotypes especially for DEN1 and DEN2, but not for DEN3 and Den4.  This method was also able to confirm the double infection DEN2-DEN3, but not for the other ones because of the unspecific pattern. From the results, it indicated that the 2 primers can be a promising early detection and serotyping method of Dengue Virus which infected the DHF patients. Key words: Dengue Virus, DHF, early detection, serotyping, RT-PCR 2 primers.

  5. Two dimensional VOPBA reveals laminin receptor (LAMR1 interaction with dengue virus serotypes 1, 2 and 3

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    Cardosa Mary

    2005-03-01

    Full Text Available Abstract Background The search for the dengue virus receptor has generated many candidates often identified only by molecular mass. The wide host range of the viruses in vitro combined with multiple approaches to identifying the receptor(s has led to the notion that many receptors or attachment proteins may be involved and that the different dengue virus serotypes may utilize different receptors on the same cells as well as on different cell types. Results In this study we used sequential extraction of PS Clone D cell monolayers with the detergent β-octylglucopyranoside followed by sodium deoxycholate to prepare a cell membrane-rich fraction. We then used 2 dimensional (2D gel electrophoresis to separate the membrane proteins and applied a modified virus overlay protein binding assay (VOPBA to show that dengue virus serotypes 1, 2 and 3 all interact with the 37 kDa/67 kDa laminin receptor (LAMR1, a common non-integrin surface protein on many cell types. Conclusion At least 3 of the 4 dengue serotypes interact with the 37 kDa/67 kDa laminin receptor, LAMR1, which may be a common player in dengue virus-cell surface interaction.

  6. Natural transovarial dengue virus infection rate in both sexes of dark and pale forms of Aedes aegypti from an urban area of Bangkok, Thailand.

    Science.gov (United States)

    Thongrungkiat, Supatra; Wasinpiyamongkol, Ladawan; Maneekan, Pannamas; Prummongkol, Samrerng; Samung, Yudthana

    2012-09-01

    Transovarial dengue virus infection status of two forms of adult Aedes aegypti (dark or Ae. aegypti type form and pale or form queenslandensis), reared from field-collected larval and pupal stages, was determined by one-step RT-PCR and dengue viral serotype by nested-PCR. Natural transovarial transmission (TOT) of dengue virus was detected in the two Ae. aegypti forms, and in both adult males and females. Male Ae. aegypti had a higher rate of TOT dengue virus infection than female. The overall minimum infection rate among the male and female populations was 19.5 and 12.3 per 1,000 mosquitoes, respectively. All four dengue serotypes were detected in mosquito samples, with DEN-4 being the predominant serotype. Thus, both male and female Ae. aegypti have influences on the epidemiology of dengue virus transmission.

  7. Preliminary study of dengue virus infection in Iran

    DEFF Research Database (Denmark)

    Chinikar, Sadegh; Ghiasi, Seyed Mojtaba; Shah-Hosseini, Nariman

    2012-01-01

    referred to the Arboviruses and Viral Haemorrhagic Fevers Laboratory of the Pasteur Institute of Iran and tested negative for Crimean-Congo Haemorrhagic Fever (CCHF) between 2000 and 2012. Serum samples from these patients were tested for the presence of specific IgG and IgM and viral nucleic acid in blood...... abroad. Of these, six cases were from the Sistan and Baluchistan province in southeast Iran and neighbouring Pakistan. Travellers play a key role in the epidemiology of dengue infection in Iran and it is recommended that travellers to endemic areas take precautionary measures to avoid mosquito bites....

  8. Infection of bone marrow cells by dengue virus in vivo.

    Science.gov (United States)

    Noisakran, Sansanee; Onlamoon, Nattawat; Hsiao, Hui-Mien; Clark, Kristina B; Villinger, Francois; Ansari, Aftab A; Perng, Guey Chuen

    2012-03-01

    Abnormal bone marrow (BM) suppression is one of the hallmarks of dengue virus (DENV) infection in patients. Although the etiology remains unclear, direct viral targeting of the BM has been reasoned to be a contributing factor. The present studies were carried out in an effort to determine the potential effect of DENV infection on the cellularity of BM using a previously established nonhuman primate model of DENV-induced coagulopathy. BM aspirates were collected at various times from the infected nonhuman primate and cells were phenotypically defined and isolated using standard flow cytometry (fluorescence-activated cell sorting). These isolated cells were subjected to detection of DENV utilizing quantitative real-time reverse transcription polymerase chain reaction, electron microscopy, and immunostaining techniques. DENV RNA was detectable by quantitative real-time reverse transcription polymerase chain reaction in BM specimens and the presence of DENV-like particles within platelet was confirmed by electron microscopy. Enumeration of BM cells revealed a transient surge in cellularity at day 1, followed by a gradual decline from days 2 to 10 post infection. Detailed phenotypic studies showed similar kinetics in the frequencies of CD41(+)CD61(+) cells, regardless of CD34 and CD45 expression. The CD61(+) cells were not only the predominant cells that stained for DENV antigen but fluorescence-activated cell sorting-assisted isolation of CD61(+) cells from the BM were shown to contain infectious DENV by coculture with Vero cells. These data support the view that intravenous infection of nonhuman primate with DENV leads to direct infection of the BM, which is likely to be a contributing factor for transient cell suppression in the peripheral blood characteristic of acute DENV infection.

  9. Induction of virus-neutralizing antibodies and T cell responses by dengue virus type 1 virus-like particles prepared from Pichia pastoris

    Institute of Scientific and Technical Information of China (English)

    TANG Yun-xia; JIANG Li-fang; ZHOU Jun-mei; YIN Yue; YANG Xiao-meng; LIU Wen-quan; FANG Dan-yun

    2012-01-01

    Background Dengue is currently a significant global health problem but no vaccines are available against the four dengue serotypes virus infections.The development of safe and effective vaccines has been hampered by the requirement of conferring complete protection against all four dengue serotypes and the lack of a convenient animal model.Virus-like particles (VLPs) have emerged as a promising subunit vaccine candidate.One strategy of vaccine development is to produce a tetravalent dengue subunit vaccine by mixing recombinant VLPs,corresponding to all four dengue virus serotypes.Towards this end,this study aimed to establish a Pichia pastoris (P.pastoris) expression system for production of dengue virus type 1 (DENV-1) VLPs and evaluate the humoral and cellular immune response of this particle in mice.Methods A recombinant yeast P.pastoris clone containing prM and E genes of DENV-1 was constructed and DENV-1 VLPs expressed by this clone were analyzed by sucrose density gradient centrifugation,Western blotting,and transmission electron microscope.Groups of mice were immunized by these particles plus adjuvant formulations,then mice were tested by ELISA and neutralization assay for humoral immune response,and by lymphocyte proliferation and cytokine production assays for a cellular immune response.Results Our data demonstrated that recombinant DENV-1 VLPs consisting of prM and E protein were successfully expressed in the yeast P.pastoris.Sera of VLPs immunized mice were shown to contain a high-titer of antibodies and the neutralization assay suggested that those antibodies neutralized virus infection in vitro.Data from the T lymphocyte proliferation assay showed proliferation of T cell,and ELISA found elevated secretion levels of interferon IFN-y and IL-4.Conclusions P.pastoris-expressed DENV-1 VLPs can induce virus neutralizing antibodies and T cell responses in immunized mice.Using P.pastoris to produce VLPs offers a promising and economic strategy for dengue virus

  10. Dengue virus M protein C-terminal peptide (DVM-C) forms ion channels.

    Science.gov (United States)

    Premkumar, A; Horan, C R; Gage, P W

    2005-03-01

    A chemically synthesized peptide consisting of the C-terminus of the M protein of the Dengue virus type 1 strain Singapore S275/90 (DVM-C) produced ion channel activity in artificial lipid bilayers. The channels had a variable conductance and were more permeable to sodium and potassium ions than to chloride ions and more permeable to chloride ions than to calcium ions. Hexamethylene amiloride (100 microM) and amantadine (10 microM), blocked channels formed by DVM-C. Ion channels may play an important role in the life cycle of many viruses and drugs that block these channels may prove to be useful antiviral agents.

  11. Cellufine sulfate column chromatography as a simple, rapid, and effective method to purify dengue virus.

    Science.gov (United States)

    Kanlaya, Rattiyaporn; Thongboonkerd, Visith

    2016-08-01

    Conventional method to purify/concentrate dengue virus (DENV) is time-consuming with low virus recovery yield. Herein, we applied cellufine sulfate column chromatography to purify/concentrate DENV based on the mimicry between heparan sulfate and DENV envelope protein. Comparative analysis demonstrated that this new method offered higher purity (as determined by less contamination of bovine serum albumin) and recovery yield (as determined by greater infectivity). Moreover, overall duration used for cellufine sulfate column chromatography to purify/concentrate DENV was approximately 1/20 of that of conventional method. Therefore, cellufine sulfate column chromatography serves as a simple, rapid, and effective alternative method for DENV purification/concentration.

  12. Transverse Myelitis as an Unusual Complication of Dengue Fever.

    Science.gov (United States)

    Mota, Mânlio Tasso de Oliveira; Estofolete, Cássia Fernanda; Zini, Nathalia; Terzian, Ana Carolina Bernardes; Gongora, Delzi Vinha Nunes; Maia, Irineu Luiz; Nogueira, Maurício Lacerda

    2017-02-08

    Dengue fever is the most common arbovirus disease, and presents with a large spectrum of clinical manifestations ranging from asymptomatic disease through to the development of dengue hemorrhagic fever. These extreme cases can lead to dengue shock syndrome, and sometimes death. Spinal cord involvement in dengue virus (DENV) infections is rare. Here, we report a case in which the patient developed acute transverse myelitis (TM) without paraparesis following a DENV infection. This case highlights the importance of physicians' awareness of the possible link between DENV and TM in endemic areas.

  13. Losartan and enalapril decrease viral absorption and interleukin 1 beta production by macrophages in an experimental dengue virus infection.

    Science.gov (United States)

    Hernández-Fonseca, Juan Pablo; Durán, Anyelo; Valero, Nereida; Mosquera, Jesús

    2015-11-01

    The role of angiotensin II (Ang II) in dengue virus infection remains unknown. The aim of this study was to determine the effect of losartan, an antagonist of the angiotensin II type 1 receptor (AT1 receptor), and enalapril, an inhibitor of angiotensin I-converting enzyme (ACE), on viral antigen expression and IL-1β production in peritoneal macrophages infected with dengue virus type 2. Mice treated with losartan or enalapril and untreated controls were infected intraperitoneally with the virus, and macrophages were analyzed. Infection resulted in increased IL-1β production and a high percentage of cells expressing viral antigen, and this was decreased by treatment with anti-Ang II drugs, suggesting a role for Ang II in dengue virus infection.

  14. Development of real time PCR for detection and quantitation of Dengue Viruses

    Directory of Open Access Journals (Sweden)

    Singh A

    2009-01-01

    Full Text Available Abstract Background Dengue virus (DENV, a mosquito borne flavivirus is an important pathogen causing more than 50 million infections every year around the world. Dengue diagnosis depends on serology, which is not useful in the early phase of the disease and virus isolation, which is laborious and time consuming. There is need for a rapid, sensitive and high throughput method for detection of DENV in the early stages of the disease. Several real-time PCR assays have been described for dengue viruses, but there is scope for improvement. The new generation TaqMan Minor Groove Binding (MGB probe approach was used to develop an improved real time RT-PCR (qRT-PCR for DENV in this study. Results The 3'UTR of thirteen Indian strains of DENV was sequenced and aligned with 41 representative sequences from GenBank. A region conserved in all four serotypes was used to target primers and probes for the qRT-PCR. A single MGB probe and a single primer pair for all the four serotypes of DENV were designed. The sensitivity of the two step qRT-PCR assay was10 copies of RNA molecules per reaction. The specificity and sensitivity of the assay was 100% when tested with a panel of 39 known positive and negative samples. Viral RNA could be detected and quantitated in infected mouse brain, cell cultures, mosquitoes and clinical samples. Viral RNA could be detected in patients even after seroconversion till 10 days post onset of infection. There was no signal with Japanese Encephalitis (JE, West Nile (WN, Chikungunya (CHK viruses or with Leptospira, Plasmodium vivax, Plasmodium falciparum and Rickettsia positive clinical samples. Conclusion We have developed a highly sensitive and specific qRT-PCR for detection and quantitation of dengue viruses. The assay will be a useful tool for differential diagnosis of dengue fever in a situation where a number of other clinically indistinguishable infectious diseases like malaria, Chikungunya, rickettsia and leptospira occur. The

  15. Insights into the molecular evolution of Dengue virus type 4 in Puerto Rico over two decades of emergence.

    Science.gov (United States)

    Martin, Estelle; Chirivella, Maritza; Co, Juliene K G; Santiago, Gilberto A; Gubler, Duane J; Muñoz-Jordán, Jorge L; Bennett, Shannon N

    2016-02-02

    Dengue has emerged globally as a major human health problem since the 1950s and is now the most important arboviral disease of humans, infecting nearly 400 million people annually. While some cases are asymptomatic, others can develop a febrile illness (dengue fever) or even progress to severe and fatal dengue. Dengue is caused by any of 4 closely related but distinct viruses, known as Dengue virus serotype 1 to 4 (DENV-1 to DENV-4) which are maintained in endemic transmission to humans in large urban centers of the tropics by Aedes mosquitoes. Since the early 1960s, Puerto Rico, a major metropolitan center in the Caribbean, has experienced increasingly larger and clinically more severe epidemics following the introduction of all four dengue serotypes. The first dengue hemorrhagic fever epidemic in 1986, and a particularly severe outbreak in 1998 were dominated by novel DENV-4 strains that evolved in Puerto Rico, replacing earlier strains and spreading throughout the region. Sequence characterization of 54 complete DENV-4 genomes and their comparative evolution against 74 previously published viral sequences from the region over several decades shows that DENV-4 strains from these periods were genetically distinct based on unique changes in the envelope and non-structural genes. Their replacement of earlier strains in Puerto Rico progressed rapidly, suggesting that strong natural selection played a role in their fixation. This study confirms that DENVs evolve through rapid lineage turnover driven in part by natural selection and genetic drift.

  16. Characterization of dengue virus 2 growth in megakaryocyte–erythrocyte progenitor cells

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Kristina B. [Division of Microbiology and Immunology, Yerkes National Primate Research Center, Emory University, Atlanta, GA (United States); Hsiao, Hui-Mien; Bassit, Leda [Center for AIDS Research, Department of Pediatrics, Emory University School of Medicine and Veterans Affairs Medical Center, Atlanta, GA (United States); Crowe, James E. [Departments of Pediatrics, Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, TN (United States); Schinazi, Raymond F. [Center for AIDS Research, Department of Pediatrics, Emory University School of Medicine and Veterans Affairs Medical Center, Atlanta, GA (United States); Perng, Guey Chuen [Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan (China); Villinger, Francois [Division of Microbiology and Immunology, Yerkes National Primate Research Center, Emory University, Atlanta, GA (United States); New Iberia Research Center, University of Louisiana at Lafayette, New Iberia, LA (United States)

    2016-06-15

    Megakaryocyte–erythrocyte progenitor (MEP) cells are potential in vivo targets of dengue virus (DENV); the virus has been found associated with megakaryocytes ex vivo and platelets during DENV-induced thrombocytopenia. We report here that DENV serotype 2 (DENV2) propagates well in human nondifferentiated MEP cell lines (Meg01 and K562). In comparison to virus propagated in Vero cells, viruses from MEP cell lines had similar structure and buoyant density. However, differences in MEP-DENV2 stability and composition were suggested by distinct protein patterns in western blot analysis. Also, antibody neutralization of envelope domain I/II on MEP-DENV2 was reduced relative to that on Vero-DENV2. Infectious DENV2 was produced at comparable kinetics and magnitude in MEP and Vero cells. However, fewer virion structures appeared in electron micrographs of MEP cells. We propose that DENV2 infects and produces virus efficiently in megakaryocytes and that megakaryocyte impairment might contribute to dengue disease pathogenesis. - Highlights: • DenV replicates efficiently in undifferentiated megakaryocyte–erythrocyte progenitors. • MEP produced DenV differs in protein content from Vero produced DenV. • MEP produced DenV may be more difficult to neutralize relative to Vero DenV.

  17. Dengue Virus Directly Stimulates Polyclonal B Cell Activation

    Science.gov (United States)

    Papa, Michelle Premazzi; de Morais, Ana Theresa Silveira; Peçanha, Ligia Maria Torres; de Arruda, Luciana Barros

    2015-01-01

    Dengue infection is associated to vigorous inflammatory response, to a high frequency of activated B cells, and to increased levels of circulating cross-reactive antibodies. We investigated whether direct infection of B cells would promote activation by culturing primary human B lymphocytes from healthy donors with DENV in vitro. B cells were susceptible, but poorly permissive to infection. Even though, primary B cells cultured with DENV induced substantial IgM secretion, which is a hallmark of polyclonal B cell activation. Notably, DENV induced the activation of B cells obtained from either DENV immune or DENV naïve donors, suggesting that it was not dependent on DENV-specific secondary/memory response. B cell stimulation was dependent on activation of MAPK and CD81. B cells cultured with DENV also secreted IL-6 and presented increased expression of CD86 and HLA-DR, which might contribute to B lymphocyte co-stimulatory function. Indeed, PBMCs, but not isolated B cells, secreted high amounts of IgG upon DENV culture, suggesting that interaction with other cell types in vivo might promote Ig isotype switching and IgG secretion from different B cell clones. These findings suggest that activation signaling pathways triggered by DENV interaction with non-specific receptors on B cells might contribute to the exacerbated response observed in dengue patients. PMID:26656738

  18. Fine Scale Spatiotemporal Clustering of Dengue Virus Transmission in Children and Aedes aegypti in Rural Thai Villages

    NARCIS (Netherlands)

    Yoon, I.K.; Getis, A.; Aldstadt, J.; Rothman, A.L.; Tannitisupawong, D.; Koenraadt, C.J.M.; Fansiri, T.; Jones, J.W.; Morrison, A.C.; Jarman, R.G.; Nisalak, A.; Mammen Jr., M.P.; Thammapalo, S.; Srikiatkhachorn, A.; Green, S.; Libraty, D.H.; Gibbons, R.V.; Endy, T.; Pimgate, C.; Scott, T.W.

    2012-01-01

    Background Based on spatiotemporal clustering of human dengue virus (DENV) infections, transmission is thought to occur at fine spatiotemporal scales by horizontal transfer of virus between humans and mosquito vectors. To define the dimensions of local transmission and quantify the factors that supp

  19. Identification of a new dengue virus inhibitor that targets the viral NS4B protein and restricts genomic RNA replication

    NARCIS (Netherlands)

    Cleef, K.W.R. van; Overheul, G.J.; Thomassen, M.C.; Kaptein, S.J.; Davidson, A.D.; Jacobs, M.; Neyts, J.; Kuppeveld, F.J.M. van; Rij, R.P. van

    2013-01-01

    Dengue virus (DENV) is an important human arthropod-borne virus with a major impact on public health. Nevertheless, a licensed vaccine or specific treatment is still lacking. We therefore screened the NIH Clinical Collection (NCC), a library of drug-like small molecules, for inhibitors of DENV repli

  20. Human Leukocyte Antigen (HLA) Class I Restricted Epitope Discovery in Yellow Fewer and Dengue Viruses: Importance of HLA Binding Strength

    DEFF Research Database (Denmark)

    Lund, Ole; Nascimento, Eduardo J. M.; Maciel, Milton, Jr

    2011-01-01

    Epitopes from all available full-length sequences of yellow fever virus (YFV) and dengue fever virus (DENV) restricted by Human Leukocyte Antigen class I (HLA-I) alleles covering 12 HLA-I supertypes were predicted using the NetCTL algorithm. A subset of 179 predicted YFV and 158 predicted DENV...

  1. The distinct distribution and phylogenetic characteristics of dengue virus serotypes/genotypes during the 2013 outbreak in Yunnan, China: Phylogenetic characteristics of 2013 dengue outbreak in Yunnan, China.

    Science.gov (United States)

    Wang, Binghui; Yang, Henglin; Feng, Yue; Zhou, Hongning; Dai, Jiejie; Hu, Yunzhang; Zhang, Li; Wang, Yajuan; Baloch, Zulqarnain; Xia, Xueshan

    2016-01-01

    Since 2000, sporadic imported cases of dengue fever were documented almost every year in Yunnan Province, China. Unexpectedly, a large-scale outbreak of dengue virus (DENV) infection occurred from August to December 2013, with 1538 documented cases. In the current study, 81 dengue-positive patient samples were collected from Xishuangbanna, the southernmost prefecture of the Yunnan province, and 23 from Dehong, the westernmost prefecture of the Yunnan province. The full-length envelope genes were amplified and sequenced. Phylogenetic analysis revealed that nine strains (39.1%) and 14 strains (60.9%) from the Dehong prefecture were classified as genotype I of DENV-1 and Asian I genotype of DENV-2, respectively. All strains from Xishuangbanna were identified as genotype II of DENV-3. Bayesian coalescent analysis indicates that the outbreak originated from bordering southeastern Asian countries. These three epidemic genotypes were predicted to originate in Thailand and then migrate into Yunnan through different routes.

  2. Repertoire of virus-derived small RNAs produced by mosquito and mammalian cells in response to dengue virus infection.

    Science.gov (United States)

    Schirtzinger, Erin E; Andrade, Christy C; Devitt, Nicholas; Ramaraj, Thiruvarangan; Jacobi, Jennifer L; Schilkey, Faye; Hanley, Kathryn A

    2015-02-01

    RNA interference (RNAi) is the major defense of many arthropods against arthropod-borne RNA viruses (arboviruses), but the role of RNAi in vertebrate immunity to arboviruses is not clear. RNA viruses can trigger RNAi in vertebrate cells, but the vertebrate interferon response may obscure this interaction. We quantified virus-derived small RNAs (vRNAs) generated by mosquito (U4.4) cells and interferon-deficient (Vero) and interferon-competent (HuH-7) mammalian cells infected with a single isolate of mosquito-borne dengue virus. Mosquito cells produced significantly more vRNAs than mammalian cells, and mosquito cell vRNAs were derived from both the positive- and negative-sense dengue genomes whereas mammalian cell vRNAs were derived primarily from positive-sense genome. Mosquito cell vRNAs were predominantly 21 nucleotides in length whereas mammalian cell vRNAs were between 12 and 36 nucleotides with a modest peak at 24 nucleotides. Hot-spots, regions of the virus genome that generated a disproportionate number of vRNAs, overlapped among the cell lines.

  3. Infecciones concurrentes por dos serotipos del virus dengue durante un brote en el noroeste de Perú, 2008

    OpenAIRE

    Mamani, Enrique; Laboratorio de Arbovirus, Centro Nacional de Salud Pública, Instituto Nacional de Salud. Lima, Perú. Biólogo. Magister en Microbiología.; Figueroa, Dana; Laboratorio de Arbovirus, Centro Nacional de Salud Pública, Instituto Nacional de Salud. Lima, Perú. Biólogo.; García, María Paquita; Laboratorio de Arbovirus, Centro Nacional de Salud Pública, Instituto Nacional de Salud. Lima, Perú. Tecnóloga Médico.; Garaycochea, María del Carmen; Laboratorio de Arbovirus, Centro Nacional de Salud Pública, Instituto Nacional de Salud. Lima, Perú. Biólogo.; Pozo, Edwar J.; Oficina de Epidemiología, Subregión de Salud Luciano Castilla. Sullana, Perú. Biólogo.

    2010-01-01

    Objetives. To establish the existence of concurrent infections by different dengue virus (DENV) serotypes in an outbreak in the Northwestern in Peru during 2008. Material and methods. 73 serum samples from patients with dengue were analyzed during an outbreak that occurred in Northwestern in Peru between May and June 2008. Molecular biology techniques were used to serotype the DENV, thus, firstly the viral RNA viral was extracted using Viral QIAamp RNA mini kit (Qiagen, Valencia, Californ...

  4. Analysis of RNA binding by the dengue virus NS5 RNA capping enzyme.

    Directory of Open Access Journals (Sweden)

    Brittney R Henderson

    Full Text Available Flaviviruses are small, capped positive sense RNA viruses that replicate in the cytoplasm of infected cells. Dengue virus and other related flaviviruses have evolved RNA capping enzymes to form the viral RNA cap structure that protects the viral genome and directs efficient viral polyprotein translation. The N-terminal domain of NS5 possesses the methyltransferase and guanylyltransferase activities necessary for forming mature RNA cap structures. The mechanism for flavivirus guanylyltransferase activity is currently unknown, and how the capping enzyme binds its diphosphorylated RNA substrate is important for deciphering how the flavivirus guanylyltransferase functions. In this report we examine how flavivirus NS5 N-terminal capping enzymes bind to the 5' end of the viral RNA using a fluorescence polarization-based RNA binding assay. We observed that the K(D for RNA binding is approximately 200 nM Dengue, Yellow Fever, and West Nile virus capping enzymes. Removal of one or both of the 5' phosphates reduces binding affinity, indicating that the terminal phosphates contribute significantly to binding. RNA binding affinity is negatively affected by the presence of GTP or ATP and positively affected by S-adensyl methoninine (SAM. Structural superpositioning of the dengue virus capping enzyme with the Vaccinia virus VP39 protein bound to RNA suggests how the flavivirus capping enzyme may bind RNA, and mutagenesis analysis of residues in the putative RNA binding site demonstrate that several basic residues are critical for RNA binding. Several mutants show differential binding to 5' di-, mono-, and un-phosphorylated RNAs. The mode of RNA binding appears similar to that found with other methyltransferase enzymes, and a discussion of diphosphorylated RNA binding is presented.

  5. Simple Prognostic Criteria can Definitively Identify Patients who Develop Severe Versus Non-Severe Dengue Disease, or Have Other Febrile Illnesses

    OpenAIRE

    Falconar, Andrew K. I.; Romero-Vivas, Claudia M. E.

    2012-01-01

    Background Severe dengue disease (SDD) (DHF/DSS: dengue hemorrhagic fever/dengue shock syndrome) results from either primary or secondary dengue virus (DENV) infections, which occur 4 - 6 days after the onset of fever. As yet, there are no definitive clinical or hematological criteria that can specifically identify SDD patients during the early acute febrile-phase of disease (day 0 - 3: < 72 hours). This study was performed during a SDD (DHF/DSS) epidemic to: 1) identify the DENV serotypes th...

  6. Vector competence of Aedes albopictus and Aedes aegypti (Diptera: Culicidae) for the DEN2-FJ10 and DEN2-FJ11 strains of the dengue 2 virus in Fujian, China.

    Science.gov (United States)

    Guo, Xiao-Xia; Li, Chun-Xiao; Zhang, Ying-Mei; Xing, Dan; Dong, Yan-De; Zhang, Heng-Duan; Qin, Cheng-Feng; Zhao, Tong-Yan

    2016-09-01

    Dengue is an acute, emerging, infectious disease transmitted by Aedes mosquitoes that has become a serious global public health problem. The DEN2-FJ10 and DEN2-FJ11 strains of the dengue 2 virus were originally isolated from the serum of a patient with dengue fever in Fujian Province, China, in 1999. Our data provide the first assessment of the vector competence of Aedes mosquitoes with respect to the DEN2-FJ10 and DEN2-FJ11 strains of the dengue virus. There were significant differences in the replication rates of these two viral strains in Aedes albopictus and Aedes aegypti (Paegypti than in Ae. albopictus 5 days post infection whereas replication of the DEN2-FJ11 was greater in Ae. albopictus than in Ae. aegypti 7 days post infection. The replicative ability of the DEN2-FJ11 strain was greater than that of the DEN2-FJ10 strain in infected Ae. albopictus. In infected Ae. aegypti, rapid proliferation of the DEN2-FJ10 strain occurred earlier than in the DEN2-FJ11 strain. There were no significant differences in the midgut and salivary gland infection rates of Ae. albopictus and Ae. aegypti with respect to either viral strain. Although the DEN2-FJ10 and DEN2-FJ11 strains differ in their virulence to neonatal rats, there was no significant difference in the ability of either Ae. albopictus or Ae. aegypti to transmit the DEN2-FJ10 and DEN2-FJ10 strains of the dengue 2 virus (P>0.05). In summary, our results indicate that Ae. albopictus and Ae. aegypti mosquitoes are moderately competent vectors of the DEN2-FJ10 and DEN2-FJ11 strains of the dengue virus and provide the first evidence of the effect of these two viral strains on the vector competence of mosquitoes in China.

  7. Functionality of dengue virus specific memory T cell responses in individuals who were hospitalized or who had mild or subclinical dengue infection.

    Directory of Open Access Journals (Sweden)

    Chandima Jeewandara

    2015-04-01

    Full Text Available Although antibody responses to dengue virus (DENV in naturally infected individuals have been extensively studied, the functionality of DENV specific memory T cell responses in relation to clinical disease severity is incompletely understood.Using ex vivo IFNγ ELISpot assays, and by determining cytokines produced in ELISpot supernatants, we investigated the functionality of DENV-specific memory T cell responses in a large cohort of individuals from Sri Lanka (n=338, who were naturally infected and were either hospitalized due to dengue or had mild or sub clinical dengue infection. We found that T cells of individuals with both past mild or sub clinical dengue infection and who were hospitalized produced multiple cytokines when stimulated with DENV-NS3 peptides. However, while DENV-NS3 specific T cells of those with mild/sub clinical dengue infection were more likely to produce only granzyme B (p=0.02, those who were hospitalized were more likely to produce both TNFα and IFNγ (p=0.03 or TNFα alone. We have also investigated the usefulness of a novel T cell based assay, which can be used to determine the past infecting DENV serotype. 92.4% of DENV seropositive individuals responded to at least one DENV serotype of this assay and none of the seronegatives responded. Individuals who were seronegative, but had received the Japanese encephalitis vaccine too made no responses, suggesting that the peptides used in this assay did not cross react with the Japanese encephalitis virus.The types of cytokines produced by DENV-specific memory T cells appear to influence the outcome of clinical disease severity. The novel T cell based assay, is likely to be useful in determining the past infecting DENV serotype in immune-epidemiological studies and also in dengue vaccine trials.

  8. Paradoxical role of antibodies in dengue virus infections: considerations for prophylactic vaccine development.

    Science.gov (United States)

    Acosta, Eliana G; Bartenschlager, Ralf

    2016-01-01

    Highly effective prophylactic vaccines for flaviviruses including yellow fever virus, tick-borne encephalitis virus and Japanese encephalitis virus are currently in use. However, the development of a dengue virus (DENV) vaccine has been hampered by the requirement of simultaneous protection against four distinct serotypes and the threat that DENV-specific antibodies might either mediate neutralization or, on the contrary, exacerbate disease through the phenomenon of antibody-dependent enhancement (ADE) of infection. Therefore, understanding the cellular, biochemical and molecular basis of antibody-mediated neutralization and ADE are fundamental for the development of a safe DENV vaccine. Here we summarize current structural and mechanistic knowledge underlying these phenomena. We also review recent results demonstrating that the humoral immune response triggered during natural DENV infection is able to generate neutralizing antibodies binding complex quaternary epitopes only present on the surface of intact virions.

  9. Dissecting the cell entry pathway of dengue virus by single-particle tracking in living cells.

    Directory of Open Access Journals (Sweden)

    Hilde M van der Schaar

    2008-12-01

    Full Text Available Dengue virus (DENV is an enveloped RNA virus that causes the most common arthropod-borne infection worldwide. The mechanism by which DENV infects the host cell remains unclear. In this work, we used live-cell imaging and single-virus tracking to investigate the cell entry, endocytic trafficking, and fusion behavior of DENV. Simultaneous tracking of DENV particles and various endocytic markers revealed that DENV enters cells exclusively via clathrin-mediated endocytosis. The virus particles move along the cell surface in a diffusive manner before being captured by a pre-existing clathrin-coated pit. Upon clathrin-mediated entry, DENV particles are transported to Rab5-positive endosomes, which subsequently mature into late endosomes through acquisition of Rab7 and loss of Rab5. Fusion of the viral membrane with the endosomal membrane was primarily detected in late endosomal compartments.

  10. The endosymbiotic bacterium Wolbachia induces resistance to dengue virus in Aedes aegypti.

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    Guowu Bian

    2010-04-01

    Full Text Available Genetic strategies that reduce or block pathogen transmission by mosquitoes have been proposed as a means of augmenting current control measures to reduce the growing burden of vector-borne diseases. The endosymbiotic bacterium Wolbachia has long been promoted as a potential vehicle for introducing disease-resistance genes into mosquitoes, thereby making them refractory to the human pathogens they transmit. Given the large overlap in tissue distribution and intracellular localization between Wolbachia and dengue virus in mosquitoes, we conducted experiments to characterize their interactions. Our results show that Wolbachia inhibits viral replication and dissemination in the main dengue vector, Aedes aegypti. Moreover, the virus transmission potential of Wolbachia-infected Ae. aegypti was significantly diminished