Should we fear "flu fear" itself? Effects of H1N1 influenza fear on ED use.

Science.gov (United States)

McDonnell, William M; Nelson, Douglas S; Schunk, Jeff E

2012-02-01

Surges in patient volumes compromise emergency departments' (EDs') ability to deliver care, as shown by the recent H1N1 influenza (flu) epidemic. Media reports are important in informing the public about health threats, but the effects of media-induced anxiety on ED volumes are unclear. The aim of this study is to examine the effect of widespread public concern about flu on ED use. We reviewed ED data from an integrated health system operating 18 hospital EDs. We compared ED visits during three 1-week periods: (a) a period of heightened public concern regarding flu before the disease was present ("Fear Week"), (b) a subsequent period of active disease ("Flu Week"), and (c) a week before widespread concern ("Control Week"). Fear Week was identified from an analysis of statewide Google electronic searches for "swine flu" and from media announcements about flu. Flu Week was identified from statewide epidemiological data. Data were reviewed from 22 608 visits during the study periods. Fear Week (n = 7712) and Flu Week (n = 7687) were compared to Control Week (n = 7209). Fear Week showed a 7.0% increase in visits (95% confidence interval, 6-8). Pediatric visits increased by 19.7%, whereas adult visits increased by 1%. Flu Week showed an increase over Control Week of 6.6% (95% confidence interval, 6-7). Pediatric visits increased by 10.6%, whereas adult visits increased by 4.8%. At a time of heightened public concern regarding flu but little disease prevalence, EDs experienced substantial increases in patient volumes. These increases were significant and comparable to the increases experienced during the subsequent epidemic of actual disease. Copyright © 2012 Elsevier Inc. All rights reserved.

Pre-infection of pigs with Mycoplasma hyopneumoniae modifies outcomes of infection with European swine influenza virus of H1N1, but not H1N2, subtype.

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Deblanc, C; Gorin, S; Quéguiner, S; Gautier-Bouchardon, A V; Ferré, S; Amenna, N; Cariolet, R; Simon, G

2012-05-25

Swine influenza virus (SIV) and Mycoplasma hyopneumoniae (Mhp) are widespread in farms and are major pathogens involved in the porcine respiratory disease complex (PRDC). The aim of this experiment was to compare the pathogenicity of European avian-like swine H1N1 and European human-like reassortant swine H1N2 viruses in naïve pigs and in pigs previously infected with Mhp. Six groups of SPF pigs were inoculated intra-tracheally with either Mhp, or H1N1, or H1N2 or Mhp+H1N1 or Mhp+H1N2, both pathogens being inoculated at 21 days intervals in these two last groups. A mock-infected group was included. Although both SIV strains induced clinical signs when singly inoculated, results indicated that the H1N2 SIV was more pathogenic than the H1N1 virus, with an earlier shedding and a greater spread in lungs. Initial infection with Mhp before SIV inoculation increased flu clinical signs and pathogenesis (hyperthermia, loss of appetite, pneumonia lesions) due to the H1N1 virus but did not modify significantly outcomes of H1N2 infection. Thus, Mhp and SIV H1N1 appeared to act synergistically, whereas Mhp and SIV H1N2 would compete, as H1N2 infection led to the elimination of Mhp in lung diaphragmatic lobes. In conclusion, SIV would be a risk factor for the severity of respiratory disorders when associated with Mhp, depending on the viral subtype involved. This experimental model of coinfection with Mhp and avian-like swine H1N1 is a relevant tool for studying the pathogenesis of SIV-associated PRDC and testing intervention strategies for the control of the disease. Copyright © 2012 Elsevier B.V. All rights reserved.

The impact of communications about swine flu (influenza A H1N1v) on public responses to the outbreak: results from 36 national telephone surveys in the UK.

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Rubin, G J; Potts, H W W; Michie, S

2010-07-01

To assess the association between levels of worry about the possibility of catching swine flu and the volume of media reporting about it; the role of psychological factors in predicting likely uptake of the swine flu vaccine; and the role of media coverage and advertising in predicting other swine flu-related behaviours. Data from a series of random-digit-dial telephone surveys were analysed. A time series analysis tested the association between levels of worry and the volume of media reporting on the start day of each survey. Cross-sectional regression analyses assessed the relationships between likely vaccine uptake or behaviour and predictor variables. Thirty-six surveys were run at, on average, weekly intervals across the UK between 1 May 2009 and 10 January 2010. Five surveys (run between 14 August and 13 September) were used to assess likely vaccine uptake. Five surveys (1-17 May) provided data relating to other behaviours. Between 1047 and 1173 people aged 16 years or over took part in each survey: 5175 participants provided data about their likely uptake of the swine flu vaccine; 5419 participants provided data relating to other behaviours. All participants were asked to state how worried they were about the possibility of personally catching swine flu. Subsets were asked how likely they were to take up a swine flu vaccination if offered it and whether they had recently carried tissues with them, bought sanitising hand gel, avoided using public transport or had been to see a general practitioner, visited a hospital or called NHS Direct for a flu-related reason. The percentage of 'very' or 'fairly' worried participants fluctuated between 9.6% and 32.9%. This figure was associated with the volume of media reporting, even after adjusting for the changing severity of the outbreak [chi2(1) = 6.6, p = 0.010, coefficient for log-transformed data = 2.6]. However, this effect only occurred during the UK's first summer wave of swine flu. In total, 56.1% of

Pandemic influenza A (H1N1)

African Journals Online (AJOL)

... in Port Shepstone, South Africa. Introduction. Influenza A (H1N1) 2009 'swine flu' variant is currently a global pandemic.1 The infection associated with this virus is usually a mild, self-limiting illness. However, it may progress to severe pneumonia requiring intensive care unit (ICU) therapy in 31% of patients.2 This may.

Knowledge, Attitude and Practices regarding Swine Flu among adult population

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Harjot Kaur

2015-09-01

Full Text Available Introduction: Prevention is the most appropriate measure to control H1N1 flu pandemic and awareness of H1N1 flu is ranked very high in preventive measures. Keeping this in view, study was designed to assess the awareness level and to compare it among urban and rural participants. Aims and objectives: To assess the knowledge, attitude and practices regarding swine flu among adult population, to assess whether there is any difference among rural and urban population and to assess the response generated by the media coverage and the Government efforts.Methods: This cross-sectional study was done from April to July 2015 on 300 houses from the urban area and 150 houses from rural area, chosen from study population by random sampling. Mean and standard deviation for continuous variables and percentages for categorical were calculated. Results: 94% of urban and 91.3% of the rural participants had previously heard about swine flu, main source being TV. 46% of urban and 74% of rural participants had myth about spread of swine flu by eating pork. 41.3% of urban and 8.7% of rural population thought that government measures are sufficient for controlling swine flu. Conclusion: Knowledge regarding swine flu pandemic is good among study participants but role of health care providers is minimal and requires more dedicated effort. Lack of awareness among study population regarding some key focus areas like health promoting habits, vaccination and myths regarding the spread is of serious concern and needs to be addressed by the media, health workers and the Government efforts

The Influenza A(H1N1)v Pandemic : An Exploratory System Dynamics Approach

NARCIS (Netherlands)

Pruyt, E.; Hamarat, C.

2010-01-01

This paper presents a small exploratory System Dynamics model related to the dynamics of the 2009 flu pandemic, also known as the Mexican flu, swine flu, or A(H1N1)v. The model was developed in May 2009 in order to quickly foster understanding about the possible dynamics of this new flu variant and

A study of the swine flu (H1N1 epidemic among health care providers of a medical college hospital of Delhi

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Om Prakash Rajoura

2011-01-01

Full Text Available Background: Influenza viruses cause annual epidemics and occasional pandemics that have claimed the lives of millions. Understanding the role of specific perceptions in motivating people to engage in precautionary behavior may help health communicators to improve their messages about outbreaks of new infectious disease generally and swine flu specifically. Objectives: To study the knowledge and practices of health care providers regarding swine flu and to study the attitudes and practices of health care providers toward the prevention of the swine flu epidemic. Materials and Methods: The present study was a cross-sectional (descriptive study and was conducted in the month of September, 2009, among doctors and nurses. A maximum of 40% of the total health care providers of GTB Hospital were covered because of feasibility and logistics, and, therefore, the sample size was 334. Results: Around 75% of the health care providers were aware about the symptoms of swine flu. Mostly, all study subjects were aware that it is transmitted through droplet infection. Correct knowledge of the incubation period of swine flu was known to 80% of the doctors and 69% of the nurses. Knowledge about high-risk groups (contacts, travelers, health care providers was observed among 88% of the doctors and 78.8% of the nurses. Practice of wearing mask during duty hours was observed among 82.6% of doctors and 85% of nurses, whereas of the total study population, only 40% were correctly using mask during duty hours. Conclusions: Significant gaps observed between knowledge and actual practice of the Health Care Provider regarding swine flu need to be filled by appropriate training. Data indicate that the health care providers are very intellectual, but they do not themselves practice what they preach.

Protective efficacy of an inactivated Eurasian avian-like H1N1 swine influenza vaccine against homologous H1N1 and heterologous H1N1 and H1N2 viruses in mice.

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Sui, Jinyu; Yang, Dawei; Qiao, Chuanling; Xu, Huiyang; Xu, Bangfeng; Wu, Yunpu; Yang, Huanliang; Chen, Yan; Chen, Hualan

2016-07-19

Eurasian avian-like H1N1 (EA H1N1) swine influenza viruses are prevalent in pigs in Europe and Asia, but occasionally cause human infection, which raises concern about their pandemic potential. Here, we produced a whole-virus inactivated vaccine with an EA H1N1 strain (A/swine/Guangxi/18/2011, SW/GX/18/11) and evaluated its efficacy against homologous H1N1 and heterologous H1N1 and H1N2 influenza viruses in mice. A strong humoral immune response, which we measured by hemagglutination inhibition (HI) and virus neutralization (VN), was induced in the vaccine-inoculated mice upon challenge. The inactivated SW/GX/18/11 vaccine provided complete protection against challenge with homologous SW/GX/18/11 virus in mice and provided effective protection against challenge with heterologous H1N1 and H1N2 viruses with distinctive genomic combinations. Our findings suggest that this EA H1N1 vaccine can provide protection against both homologous H1N1 and heterologous H1N1 or H1N2 virus infection. As such, it is an excellent vaccine candidate to prevent H1N1 swine influenza. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparative pathology of pigs infected with Korean H1N1, H1N2, or H3N2 swine influenza A viruses

OpenAIRE

Lyoo, Kwang-Soo; Kim, Jeong-Ki; Jung, Kwonil; Kang, Bo-Kyu; Song, Daesub

2014-01-01

Background The predominant subtypes of swine influenza A virus (SIV) in Korea swine population are H1N1, H1N2, and H3N2. The viruses are genetically close to the classical U.S. H1N1 and triple-reassortant H1N2 and H3N2 viruses, respectively. Comparative pathogenesis caused by Korean H1N1, H1N2, and H3N2 SIV was evaluated in this study. Findings The H3N2 infected pigs had severe scores of gross and histopathological lesions at post-inoculation days (PID) 2, and this then progressively decrease...

Identification of swine H1N2/pandemic H1N1 reassortant influenza virus in pigs, United States.

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Ali, Ahmed; Khatri, Mahesh; Wang, Leyi; Saif, Yehia M; Lee, Chang-Won

2012-07-06

In October and November 2010, novel H1N2 reassortant influenza viruses were identified from pigs showing mild respiratory signs that included cough and depression. Sequence and phylogenetic analysis showed that the novel H1N2 reassortants possesses HA and NA genes derived from recent H1N2 swine isolates similar to those isolated from Midwest. Compared to the majority of reported reassortants, both viruses preserved human-like host restrictive and putative antigenic sites in their HA and NA genes. The four internal genes, PB2, PB1, PA, and NS were similar to the contemporary swine triple reassortant viruses' internal genes (TRIG). Interestingly, NP and M genes of the novel reassortants were derived from the 2009 pandemic H1N1. The NP and M proteins of the two isolates demonstrated one (E16G) and four (G34A, D53E, I109T, and V313I) amino acid changes in the M2 and NP proteins, respectively. Similar amino acid changes were also noticed upon incorporation of the 2009 pandemic H1N1 NP in other reassortant viruses reported in the U.S. Thus the role of those amino acids in relation to host adaptation need to be further investigated. The reassortments of pandemic H1N1 with swine influenza viruses and the potential of interspecies transmission of these reassortants from swine to other species including human indicate the importance of systematic surveillance of swine population to determine the origin, the prevalence of similar reassortants in the U.S. and their impact on both swine production and public health. Copyright © 2012 Elsevier B.V. All rights reserved.

Swine flu - A pandemic outbreak

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Jini George

Full Text Available Hippocrates had described influenza like outbreak in 412 B.C. and since then repeated influenza like epidemics and pandemics have been recorded in recent times. One of the greatest killers of all time was the pandemic of swine flu (Spanish flu of 1918-1919, when 230 million people died. Annual influenza epidemics are estimated to affect 5–15% of the global population, resulting in severe illness in 3–5 million patients causing 250,000–500,000 deaths worldwide. Severe illness and deaths occur mainly in the high-risk populations of infants, the elderly and chronically ill patients. The 2009 outbreak of swine flu is thought to be a mutation more specifically a reassortment of four known strains of influenza A virus subtype H1N1; one endemic in humans, one endemic in birds, and two endemic in pigs. WHO officially declared the outbreak to be a pandemic on June 11, 2009, but stressed that the new designation was a result of the global "spread of the virus," not its severity. [Vet World 2009; 2(12.000: 472-474

Early assessment of anxiety and behavioral response to novel swine-origin influenza A(H1N1.

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James Holland Jones

Full Text Available BACKGROUND: Since late April, 2009, a novel influenza virus A (H1N1, generally referred to as the "swine flu," has spread around the globe and infected hundreds of thousands of people. During the first few days after the initial outbreak in Mexico, extensive media coverage together with a high degree of uncertainty about the transmissibility and mortality rate associated with the virus caused widespread concern in the population. The spread of an infectious disease can be strongly influenced by behavioral changes (e.g., social distancing during the early phase of an epidemic, but data on risk perception and behavioral response to a novel virus is usually collected with a substantial delay or after an epidemic has run its course. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report the results from an online survey that gathered data (n = 6,249 about risk perception of the Influenza A(H1N1 outbreak during the first few days of widespread media coverage (April 28-May 5, 2009. We find that after an initially high level of concern, levels of anxiety waned along with the perception of the virus as an immediate threat. Overall, our data provide evidence that emotional status mediates behavioral response. Intriguingly, principal component analysis revealed strong clustering of anxiety about swine flu, bird flu and terrorism. All three of these threats receive a great deal of media attention and their fundamental uncertainty is likely to generate an inordinate amount of fear vis-a-vis their actual threat. CONCLUSIONS/SIGNIFICANCE: Our results suggest that respondents' behavior varies in predictable ways. Of particular interest, we find that affective variables, such as self-reported anxiety over the epidemic, mediate the likelihood that respondents will engage in protective behavior. Understanding how protective behavior such as social distancing varies and the specific factors that mediate it may help with the design of epidemic control strategies.

In vitro reassortment between endemic H1N2 and 2009 H1N1 pandemic swine influenza viruses generates attenuated viruses.

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Ben M Hause

Full Text Available The pandemic H1N1 (pH1N1 influenza virus was first reported in humans in the spring of 2009 and soon thereafter was identified in numerous species, including swine. Reassortant viruses, presumably arising from the co-infection of pH1N1 and endemic swine influenza virus (SIV, were subsequently identified from diagnostic samples collected from swine. In this study, co-infection of swine testicle (ST cells with swine-derived endemic H1N2 (MN745 and pH1N1 (MN432 yielded two reassortant H1N2 viruses (R1 and R2, both possessing a matrix gene derived from pH1N1. In ST cells, the reassortant viruses had growth kinetics similar to the parental H1N2 virus and reached titers approximately 2 log(10 TCID(50/mL higher than the pH1N1 virus, while in A549 cells these viruses had similar growth kinetics. Intranasal challenge of pigs with H1N2, pH1N1, R1 or R2 found that all viruses were capable of infecting and transmitting between direct contact pigs as measured by real time reverse transcription PCR of nasal swabs. Lung samples were also PCR-positive for all challenge groups and influenza-associated microscopic lesions were detected by histology. Interestingly, infectious virus was detected in lung samples for pigs challenged with the parental H1N2 and pH1N1 at levels significantly higher than either reassortant virus despite similar levels of viral RNA. Results of our experiment suggested that the reassortant viruses generated through in vitro cell culture system were attenuated without gaining any selective growth advantage in pigs over the parental lineages. Thus, reassortant influenza viruses described in this study may provide a good system to study genetic basis of the attenuation and its mechanism.

Experimental infection with H1N1 European swine influenza virus protects pigs from an infection with the 2009 pandemic H1N1 human influenza virus.

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Busquets, Núria; Segalés, Joaquim; Córdoba, Lorena; Mussá, Tufaria; Crisci, Elisa; Martín-Valls, Gerard E; Simon-Grifé, Meritxell; Pérez-Simó, Marta; Pérez-Maíllo, Monica; Núñez, Jose I; Abad, Francesc X; Fraile, Lorenzo; Pina, Sonia; Majó, Natalia; Bensaid, Albert; Domingo, Mariano; Montoya, María

2010-01-01

The recent pandemic caused by human influenza virus A(H1N1) 2009 contains ancestral gene segments from North American and Eurasian swine lineages as well as from avian and human influenza lineages. The emergence of this A(H1N1) 2009 poses a potential global threat for human health and the fact that it can infect other species, like pigs, favours a possible encounter with other influenza viruses circulating in swine herds. In Europe, H1N1, H1N2 and H3N2 subtypes of swine influenza virus currently have a high prevalence in commercial farms. To better assess the risk posed by the A(H1N1) 2009 in the actual situation of swine farms, we sought to analyze whether a previous infection with a circulating European avian-like swine A/Swine/Spain/53207/2004 (H1N1) influenza virus (hereafter referred to as SwH1N1) generated or not cross-protective immunity against a subsequent infection with the new human pandemic A/Catalonia/63/2009 (H1N1) influenza virus (hereafter referred to as pH1N1) 21 days apart. Pigs infected only with pH1N1 had mild to moderate pathological findings, consisting on broncho-interstitial pneumonia. However, pigs inoculated with SwH1N1 virus and subsequently infected with pH1N1 had very mild lung lesions, apparently attributed to the remaining lesions caused by SwH1N1 infection. These later pigs also exhibited boosted levels of specific antibodies. Finally, animals firstly infected with SwH1N1 virus and latter infected with pH1N1 exhibited undetectable viral RNA load in nasal swabs and lungs after challenge with pH1N1, indicating a cross-protective effect between both strains. © INRA, EDP Sciences, 2010.

The neuropsychiatric aspects of influenza/swine flu: A selective review

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Narayana Manjunatha

2011-01-01

Full Text Available The world witnessed the influenza virus during the seasonal epidemics and pandemics. The current strain of H1N1 (swine flu pandemic is believed to be the legacy of the influenza pandemic (1918-19. The influenza virus has been implicated in many neuropsychiatric disorders. In view of the recent pandemic, it would be interesting to review the neuropsychiatric aspects of influenza, specifically swine flu. Author used popular search engine ′PUBMED′ to search for published articles with different MeSH terms using Boolean operator (AND. Among these, a selective review of the published literature was done. Acute manifestations of swine flu varied from behavioral changes, fear of misdiagnosis during outbreak, neurological features like seizures, encephalopathy, encephalitis, transverse myelitis, aseptic meningitis, multiple sclerosis, and Guillian-Barre Syndrome. Among the chronic manifestations, schizophrenia, Parkinson′s disease, mood disorder, dementia, and mental retardation have been hypothesized. Further research is required to understand the etiological hypothesis of the chronic manifestations of influenza. The author urges neuroscientists around the world to make use of the current swine flu pandemic as an opportunity for further research.

Identification of Human H1N2 and Human-Swine Reassortant H1N2 and H1N1 Influenza A Viruses among Pigs in Ontario, Canada (2003 to 2005)†

OpenAIRE

Karasin, Alexander I.; Carman, Suzanne; Olsen, Christopher W.

2006-01-01

Since 2003, three novel genotypes of H1 influenza viruses have been recovered from Canadian pigs, including a wholly human H1N2 virus and human-swine reassortants. These isolates demonstrate that human-lineage H1N2 viruses are infectious for pigs and that viruses with a human PB1/swine PA/swine PB2 polymerase complex can replicate in pigs.

Reassortant swine influenza viruses isolated in Japan contain genes from pandemic A(H1N1) 2009.

Science.gov (United States)

Kanehira, Katsushi; Takemae, Nobuhiro; Uchida, Yuko; Hikono, Hirokazu; Saito, Takehiko

2014-06-01

In 2013, three reassortant swine influenza viruses (SIVs)-two H1N2 and one H3N2-were isolated from symptomatic pigs in Japan; each contained genes from the pandemic A(H1N1) 2009 virus and endemic SIVs. Phylogenetic analysis revealed that the two H1N2 viruses, A/swine/Gunma/1/2013 and A/swine/Ibaraki/1/2013, were reassortants that contain genes from the following three distinct lineages: (i) H1 and nucleoprotein (NP) genes derived from a classical swine H1 HA lineage uniquely circulating among Japanese SIVs; (ii) neuraminidase (NA) genes from human-like H1N2 swine viruses; and (iii) other genes from pandemic A(H1N1) 2009 viruses. The H3N2 virus, A/swine/Miyazaki/2/2013, comprised genes from two sources: (i) hemagglutinin (HA) and NA genes derived from human and human-like H3N2 swine viruses and (ii) other genes from pandemic A(H1N1) 2009 viruses. Phylogenetic analysis also indicated that each of the reassortants may have arisen independently in Japanese pigs. A/swine/Miyazaki/2/2013 were found to have strong antigenic reactivities with antisera generated for some seasonal human-lineage viruses isolated during or before 2003, whereas A/swine/Miyazaki/2/2013 reactivities with antisera against viruses isolated after 2004 were clearly weaker. In addition, antisera against some strains of seasonal human-lineage H1 viruses did not react with either A/swine/Gunma/1/2013 or A/swine/Ibaraki/1/2013. These findings indicate that emergence and spread of these reassortant SIVs is a potential public health risk. © 2014 The Societies and Wiley Publishing Asia Pty Ltd.

Characterization of a newly emerged genetic cluster of H1N1 and H1N2 swine influenza virus in the United States.

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Vincent, Amy L; Ma, Wenjun; Lager, Kelly M; Gramer, Marie R; Richt, Juergen A; Janke, Bruce H

2009-10-01

H1 influenza A viruses that were distinct from the classical swine H1 lineage were identified in pigs in Canada in 2003–2004; antigenic and genetic characterization identified the hemagglutinin (HA) as human H1 lineage. The viruses identified in Canadian pigs were human lineage in entirety or double (human–swine) reassortants. Here, we report the whole genome sequence analysis of four human-like H1 viruses isolated from U.S. swine in 2005 and 2007. All four isolates were characterized as triple reassortants with an internal gene constellation similar to contemporary U.S. swine influenza virus (SIV), with HA and neuraminidase (NA) most similar to human influenza virus lineages. A 2007 human-like H1N1 was evaluated in a pathogenesis and transmission model and compared to a 2004 reassortant H1N1 SIV isolate with swine lineage HA and NA. The 2007 isolate induced disease typical of influenza virus and was transmitted to contact pigs; however, the kinetics and magnitude differed from the 2004 H1N1 SIV. This study indicates that the human-like H1 SIV can efficiently replicate and transmit in the swine host and now co-circulates with contemporary SIVs as a distinct genetic cluster of H1 SIV.

Two genotypes of H1N2 swine influenza viruses appeared among pigs in China.

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Xu, Chuantian; Zhu, Qiyun; Yang, Huanliang; Zhang, Xiumei; Qiao, Chuanling; Chen, Yan; Xin, Xiaoguang; Chen, Hualan

2009-10-01

H1N2 is one of the main subtypes of influenza, which circulates in swine all over the world. To investigate the prevalence and genetic of H1N2 in swine of China. Two H1N2 swine influenza viruses were isolated from Tianjin and Guangdong province of China in 2004 and 2006, respectively. The molecular evolution of eight gene segments was analyzed. A/Swine/Tianjin/1/2004 has low identity with A/Swine/Guangdong/2006; in the phylogenetic tree of PA gene, A/Swine/Guangdong/1/2006 and A/Swine/Guangxi/1/2006 along with the H1N2 swine isolates of North America formed a cluster; and A/Swine/Tianjin/2004 and A/Swine/Zhejiang/2004, along with the classical H1N1 swine isolates formed another cluster; except that NA gene of A/Swine/Tianjin/1/2004 fell into the cluster of the H3N2 human influenza virus, indicating the reassortment between H3N2 human and H1N1 swine influenza viruses. Two different genotypes of H1N2 appeared among pigs in China. A/swine/Guangdong/1/06 was probably from H1N2 swine influenza viruses of North America; while A/swine/Tianjin/1/04 maybe come from reassortments of classical H1N1 swine and H3N2 human viruses prevalent in North America.

Molecular evolution of H1N1 swine influenza in Guangdong, China, 2016-2017.

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Cai, Mengkai; Huang, Junming; Bu, Dexin; Yu, Zhiqing; Fu, Xinliang; Ji, Chihai; Zhou, Pei; Zhang, Guihong

2018-06-01

Swine are the main host of the H1N1 swine influenza virus (SIV), however, H1N1 can also infect humans and occasionally cause serious respiratory disease. To trace the evolution of the SIV in Guangdong, China, we performed an epidemic investigation during the period of 2016-2017. Nine H1N1 influenza viruses were isolated from swine nasal swabs. Antigenic analysis revealed that these viruses belonged to two distinct antigenic groups, represented by A/Swine/Guangdong/101/2016 and A/Swine/Guangdong/52/2017. Additionally, three genotypes, known as GD52/17-like, GD493/17-like and GD101/16-like, were identified by phylogenetic analysis. Importantly, the genotypes including a minimum of 4 pdm/09-origin internal genes have become prevalent in China in recent years. A total of 2966 swine serum samples were used to perform hemagglutination inhibition (HI) tests, and the results showed that the seroprevalence values of SW/GD/101/16 (32.2% in 2016, 32.1% in 2017) were significantly higher than the seroprevalence values of SW/GD/52/17 (18.0% in 2016, 16.7% in 2017). Our study showed that the three reassortant genotypes of H1N1 SIV currently circulating in China are stable, but H1N1pdm09 poses challenges to human health by the introduction of internal genes into these reassortant genotypes. Strengthening SIV surveillance is therefore critical for SIV control and minimizing its potential threat to public health. Copyright © 2018 Elsevier B.V. All rights reserved.

Comparative pathology of pigs infected with Korean H1N1, H1N2, or H3N2 swine influenza A viruses.

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Lyoo, Kwang-Soo; Kim, Jeong-Ki; Jung, Kwonil; Kang, Bo-Kyu; Song, Daesub

2014-09-24

The predominant subtypes of swine influenza A virus (SIV) in Korea swine population are H1N1, H1N2, and H3N2. The viruses are genetically close to the classical U.S. H1N1 and triple-reassortant H1N2 and H3N2 viruses, respectively. Comparative pathogenesis caused by Korean H1N1, H1N2, and H3N2 SIV was evaluated in this study. The H3N2 infected pigs had severe scores of gross and histopathological lesions at post-inoculation days (PID) 2, and this then progressively decreased. Both the H1N1 and H1N2 infected pigs lacked gross lesions at PID 2, but they showed moderate to severe pneumonia on PID 4, 7 and 14. The pigs infected with H1N1 had significant scores of gross and histopathological lesions when compared with the other pigs infected with H1N2, H3N2, and mock at PID 14. Mean SIV antigen-positive scores were rarely detected for pigs infected with H1N2 and H3N2 from PID 7, whereas a significantly increased amount of viral antigens were found in the bronchioles and alveolar epithelium of the H1N1infected pigs at PID 14. We demonstrated that Korean SIV subtypes had different pulmonary pathologic patterns. The Korean H3N2 rapidly induced acute lung lesions such as broncho-interstitial pneumonia, while the Korean H1N1 showed longer course of infection as compared to other strains.

H1N1 influenza viruses varying widely in hemagglutinin stability transmit efficiently from swine to swine and to ferrets.

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Marion Russier

2017-03-01

Full Text Available A pandemic-capable influenza virus requires a hemagglutinin (HA surface glycoprotein that is immunologically unseen by most people and is capable of supporting replication and transmission in humans. HA stabilization has been linked to 2009 pH1N1 pandemic potential in humans and H5N1 airborne transmissibility in the ferret model. Swine have served as an intermediate host for zoonotic influenza viruses, yet the evolutionary pressure exerted by this host on HA stability was unknown. For over 70 contemporary swine H1 and H3 isolates, we measured HA activation pH to range from pH 5.1 to 5.9 for H1 viruses and pH 5.3 to 5.8 for H3 viruses. Thus, contemporary swine isolates vary widely in HA stability, having values favored by both avian (pH >5.5 and human and ferret (pH ≤5.5 species. Using an early 2009 pandemic H1N1 (pH1N1 virus backbone, we generated three viruses differing by one HA residue that only altered HA stability: WT (pH 5.5, HA1-Y17H (pH 6.0, and HA2-R106K (pH 5.3. All three replicated in pigs and transmitted from pig-to-pig and pig-to-ferret. WT and R106 viruses maintained HA genotype and phenotype after transmission. Y17H (pH 6.0 acquired HA mutations that stabilized the HA protein to pH 5.8 after transmission to pigs and 5.5 after transmission to ferrets. Overall, we found swine support a broad range of HA activation pH for contact transmission and many recent swine H1N1 and H3N2 isolates have stabilized (human-like HA proteins. This constitutes a heightened pandemic risk and underscores the importance of ongoing surveillance and control efforts for swine viruses.

Acute necrotizing encephalopathy of childhood: a fatal complication of swine flu

International Nuclear Information System (INIS)

Khan, M.R.; Maheshwari, P.K.; Haque, A.

2010-01-01

Acute necrotizing encephalopathy of childhood (ANEC) is a rare condition characterized by the presence of multifocal symmetrical brain lesions involving mainly thalami, brainstem, cerebellum and white matter. ANEC is a serious and life threatening complication of simple viral infections. We present a case of a young child who developed this condition with classical clinical and radiological findings consistent with ANEC, secondary to swine flu (H1N1). He needed ventilatory support and had profound motor and intellectual deficit on discharge. We report this case with aim of raising awareness about this fatal complication of swine flu which has become a global health care issue these days. (author)

Factors Affecting Intention among Students to Be Vaccinated against A/H1N1 Influenza: A Health Belief Model Approach

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Sharon Teitler-Regev

2011-01-01

Full Text Available The outbreak of A/H1N1 influenza (henceforth, swine flu in 2009 was characterized mainly by morbidity rates among young people. This study examined the factors affecting the intention to be vaccinated against the swine flu among students in Israel. Questionnaires were distributed in December 2009 among 387 students at higher-education institutions. The research questionnaire included sociodemographic characteristics and Health Belief Model principles. The results show that the factors positively affecting the intention to take the swine flu vaccine were past experience with seasonal flu shot and three HBM categories: higher levels of perceived susceptibility for catching the illness, perceived seriousness of illness, and lower levels of barriers. We conclude that offering the vaccine at workplaces may raise the intention to take the vaccine among young people in Israel.

Molecular characterization of a novel reassortant H1N2 influenza virus containing genes from the 2009 pandemic human H1N1 virus in swine from eastern China.

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Peng, Xiuming; Wu, Haibo; Xu, Lihua; Peng, Xiaorong; Cheng, Linfang; Jin, Changzhong; Xie, Tiansheng; Lu, Xiangyun; Wu, Nanping

2016-06-01

Pandemic outbreaks of H1N1 swine influenza virus have been reported since 2009. Reassortant H1N2 viruses that contain genes from the pandemic H1N1 virus have been isolated in Italy and the United States. However, there is limited information regarding the molecular characteristics of reassortant H1N2 swine influenza viruses in eastern China. Active influenza surveillance programs in Zhejiang Province identified a novel H1N2 influenza virus isolated from pigs displaying clinical signs of influenza virus infection. Whole-genome sequencing was performed and this strain was compared with other influenza viruses available in GenBank. Phylogenetic analysis suggested that the novel strain contained genes from the 2009 pandemic human H1N1 and swine H3N2 viruses. BALB/c mice were infected with the isolated virus to assess its virulence in mice. While the novel H1N2 isolate replicated well in mice, it was found to be less virulent. These results provide additional evidence that swine serve as intermediate hosts or 'mixing vessels' for novel influenza viruses. They also emphasize the importance of surveillance in the swine population for use as an early warning system for influenza outbreaks in swine and human populations.

Modified vaccinia virus Ankara expressing the hemagglutinin of pandemic (H1N1) 2009 virus induces cross-protective immunity against Eurasian 'avian-like' H1N1 swine viruses in mice.

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Castrucci, Maria R; Facchini, Marzia; Di Mario, Giuseppina; Garulli, Bruno; Sciaraffia, Ester; Meola, Monica; Fabiani, Concetta; De Marco, Maria A; Cordioli, Paolo; Siccardi, Antonio; Kawaoka, Yoshihiro; Donatelli, Isabella

2014-05-01

To examine cross-reactivity between hemagglutinin (HA) derived from A/California/7/09 (CA/09) virus and that derived from representative Eurasian "avian-like" (EA) H1N1 swine viruses isolated in Italy between 1999 and 2008 during virological surveillance in pigs. Modified vaccinia virus Ankara (MVA) expressing the HA gene of CA/09 virus (MVA-HA-CA/09) was used as a vaccine to investigate cross-protective immunity against H1N1 swine viruses in mice. Two classical swine H1N1 (CS) viruses and four representative EA-like H1N1 swine viruses previously isolated during outbreaks of respiratory disease in pigs on farms in Northern Italy were used in this study. Female C57BL/6 mice were vaccinated with MVA/HA/CA/09 and then challenged intranasally with H1N1 swine viruses. Cross-reactive antibody responses were determined by hemagglutination- inhibition (HI) and virus microneutralizing (MN) assays of sera from MVA-vaccinated mice. The extent of protective immunity against infection with H1N1 swine viruses was determined by measuring lung viral load on days 2 and 4 post-challenge. Systemic immunization of mice with CA/09-derived HA, vectored by MVA, elicited cross-protective immunity against recent EA-like swine viruses. This immune protection was related to the levels of cross-reactive HI antibodies in the sera of the immunized mice and was dependent on the similarity of the antigenic site Sa of H1 HAs. Our findings suggest that the herd immunity elicited in humans by the pandemic (H1N1) 2009 virus could limit the transmission of recent EA-like swine HA genes into the influenza A virus gene pool in humans. © 2013 The Authors Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Reassortant H1N1 influenza virus vaccines protect pigs against pandemic H1N1 influenza virus and H1N2 swine influenza virus challenge.

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Yang, Huanliang; Chen, Yan; Shi, Jianzhong; Guo, Jing; Xin, Xiaoguang; Zhang, Jian; Wang, Dayan; Shu, Yuelong; Qiao, Chuanling; Chen, Hualan

2011-09-28

Influenza A (H1N1) virus has caused human influenza outbreaks in a worldwide pandemic since April 2009. Pigs have been found to be susceptible to this influenza virus under experimental and natural conditions, raising concern about their potential role in the pandemic spread of the virus. In this study, we generated a high-growth reassortant virus (SC/PR8) that contains the hemagglutinin (HA) and neuraminidase (NA) genes from a novel H1N1 isolate, A/Sichuan/1/2009 (SC/09), and six internal genes from A/Puerto Rico/8/34 (PR8) virus, by genetic reassortment. The immunogenicity and protective efficacy of this reassortant virus were evaluated at different doses in a challenge model using a homologous SC/09 or heterologous A/Swine/Guangdong/1/06(H1N2) virus (GD/06). Two doses of SC/PR8 virus vaccine elicited high-titer serum hemagglutination inhibiting (HI) antibodies specific for the 2009 H1N1 virus and conferred complete protection against challenge with either SC/09 or GD/06 virus, with reduced lung lesions and viral shedding in vaccine-inoculated animals compared with non-vaccinated control animals. These results indicated for the first time that a high-growth SC/PR8 reassortant H1N1 virus exhibits properties that are desirable to be a promising vaccine candidate for use in swine in the event of a pandemic H1N1 influenza. Copyright © 2011 Elsevier B.V. All rights reserved.

CDC Recommendations to Reduce the Risk of H3N2v Flu Virus Infection for Fairgoers and Swine Exhibitors

Centers for Disease Control (CDC) Podcasts

2012-09-10

In this podcast, Dr. Lyn Finelli discusses CDC’s recommendations for reducing the risk of infection with H3N2v flu viruses for fairgoers and swine exhibitors.  Created: 9/10/2012 by National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 9/10/2012.

Is it a policy crisis or it is a health crisis? The Egyptian context--analysis of the Egyptian health policy for the H1N1 flu pandemic control.

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Seef, Sameh; Jeppsson, Anders

2013-01-01

A new influenza virus that was first detected in people in April 2009, was initially referred to colloquially as "swine flu", since it contained genes from swine, avian and human influenza viruses. It can, however, not be transmitted by eating pork or dealing with pigs. In Egypt, several hundred thousand pigs were killed in May, in spite of advice from global health authorities that such an action was unnecessary. Pigs are raised and consumed mainly by the Christian minority, which constitute some 10% of the population. Health Ministry estimated there were between 300,000-350,000 pigs in Egypt. This paper will analyze the Egyptian health policy for controlling the pandemic H1N1 flu, exploring its context, content, process, and actors. The analysis is based on the Leichter Context, which refers to systemic factors-political, economic and social, both national and international-that may have an effect on health policy, and is based on data collected from literature review and policy documents. The International health officials said the swine flu virus that has caused worldwide fear is not transmitted by pigs, and that pig slaughters do nothing to stop its spread. The WHO stopped using the term "swine flu" to avoid confusion. In Egypt, even the editor of a pro-government newspaper criticized the order to slaughter: "Killing (pigs) is not a solution, otherwise, we should kill the people, because the virus spreads through them," wrote Abdullah Kamal of the daily Rose El-Youssef. The World Health organization also criticized the decision. The extinction of the Egyptian pigs is an example of how a health issue can be used to persecute a minority within a country. Although the current influenza has nothing whatsoever to do with pigs, the previous name of the epidemic was used as an argument to violate the rights of the Christian minority in Egypt.

Antigenic variation of H1N1, H1N2 and H3N2 swine influenza viruses in Japan and Vietnam.

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Takemae, Nobuhiro; Nguyen, Tung; Ngo, Long Thanh; Hiromoto, Yasuaki; Uchida, Yuko; Pham, Vu Phong; Kageyama, Tsutomu; Kasuo, Shizuko; Shimada, Shinichi; Yamashita, Yasutaka; Goto, Kaoru; Kubo, Hideyuki; Le, Vu Tri; Van Vo, Hung; Do, Hoa Thi; Nguyen, Dang Hoang; Hayashi, Tsuyoshi; Matsuu, Aya; Saito, Takehiko

2013-04-01

The antigenicity of the influenza A virus hemagglutinin is responsible for vaccine efficacy in protecting pigs against swine influenza virus (SIV) infection. However, the antigenicity of SIV strains currently circulating in Japan and Vietnam has not been well characterized. We examined the antigenicity of classical H1 SIVs, pandemic A(H1N1)2009 (A(H1N1)pdm09) viruses, and seasonal human-lineage SIVs isolated in Japan and Vietnam. A hemagglutination inhibition (HI) assay was used to determine antigenic differences that differentiate the recent Japanese H1N2 and H3N2 SIVs from the H1N1 and H3N2 domestic vaccine strains. Minor antigenic variation between pig A(H1N1)pdm09 viruses was evident by HI assay using 13 mAbs raised against homologous virus. A Vietnamese H1N2 SIV, whose H1 gene originated from a human strain in the mid-2000s, reacted poorly with post-infection ferret serum against human vaccine strains from 2000-2010. These results provide useful information for selection of optimal strains for SIV vaccine production.

Swine Influenza Virus (H1N2) Characterization and Transmission in Ferrets, Chile.

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Bravo-Vasquez, Nicolás; Karlsson, Erik A; Jimenez-Bluhm, Pedro; Meliopoulos, Victoria; Kaplan, Bryan; Marvin, Shauna; Cortez, Valerie; Freiden, Pamela; Beck, Melinda A; Hamilton-West, Christopher; Schultz-Cherry, Stacey

2017-02-01

Phylogenetic analysis of the influenza hemagglutinin gene (HA) has suggested that commercial pigs in Chile harbor unique human seasonal H1-like influenza viruses, but further information, including characterization of these viruses, was unavailable. We isolated influenza virus (H1N2) from a swine in a backyard production farm in Central Chile and demonstrated that the HA gene was identical to that in a previous report. Its HA and neuraminidase genes were most similar to human H1 and N2 viruses from the early 1990s and internal segments were similar to influenza A(H1N1)pdm09 virus. The virus replicated efficiently in vitro and in vivo and transmitted in ferrets by respiratory droplet. Antigenically, it was distinct from other swine viruses. Hemagglutination inhibition analysis suggested that antibody titers to the swine Chilean H1N2 virus were decreased in persons born after 1990. Further studies are needed to characterize the potential risk to humans, as well as the ecology of influenza in swine in South America.

The nonadaptive nature of the H1N1 2009 Swine Flu pandemic contrasts with the adaptive facilitation of transmission to a new host

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Abdussamad Juwaeriah

2011-01-01

Full Text Available Abstract Background The emergence of the 2009 H1N1 Influenza pandemic followed a multiple reassortment event from viruses originally circulating in swines and humans, but the adaptive nature of this emergence is poorly understood. Results Here we base our analysis on 1180 complete genomes of H1N1 viruses sampled in North America between 2000 and 2010 in swine and human hosts. We show that while transmission to a human host might require an adaptive phase in the HA and NA antigens, the emergence of the 2009 pandemic was essentially nonadaptive. A more detailed analysis of the NA protein shows that the 2009 pandemic sequence is characterized by novel epitopes and by a particular substitution in loop 150, which is responsible for a nonadaptive structural change tightly associated with the emergence of the pandemic. Conclusions Because this substitution was not present in the 1918 H1N1 pandemic virus, we posit that the emergence of pandemics is due to epistatic interactions between sites distributed over different segments. Altogether, our results are consistent with population dynamics models that highlight the epistatic and nonadaptive rise of novel epitopes in viral populations, followed by their demise when the resulting virus is too virulent.

Antigenically Diverse Swine Origin H1N1 Variant Influenza Viruses Exhibit Differential Ferret Pathogenesis and Transmission Phenotypes.

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Pulit-Penaloza, Joanna A; Jones, Joyce; Sun, Xiangjie; Jang, Yunho; Thor, Sharmi; Belser, Jessica A; Zanders, Natosha; Creager, Hannah M; Ridenour, Callie; Wang, Li; Stark, Thomas J; Garten, Rebecca; Chen, Li-Mei; Barnes, John; Tumpey, Terrence M; Wentworth, David E; Maines, Taronna R; Davis, C Todd

2018-06-01

Influenza A(H1) viruses circulating in swine represent an emerging virus threat, as zoonotic infections occur sporadically following exposure to swine. A fatal infection caused by an H1N1 variant (H1N1v) virus was detected in a patient with reported exposure to swine and who presented with pneumonia, respiratory failure, and cardiac arrest. To understand the genetic and phenotypic characteristics of the virus, genome sequence analysis, antigenic characterization, and ferret pathogenesis and transmissibility experiments were performed. Antigenic analysis of the virus isolated from the fatal case, A/Ohio/09/2015, demonstrated significant antigenic drift away from the classical swine H1N1 variant viruses and H1N1 pandemic 2009 viruses. A substitution in the H1 hemagglutinin (G155E) was identified that likely impacted antigenicity, and reverse genetics was employed to understand the molecular mechanism of antibody escape. Reversion of the substitution to 155G, in a reverse genetics A/Ohio/09/2015 virus, showed that this residue was central to the loss of hemagglutination inhibition by ferret antisera raised against a prototypical H1N1 pandemic 2009 virus (A/California/07/2009), as well as gamma lineage classical swine H1N1 viruses, demonstrating the importance of this residue for antibody recognition of this H1 lineage. When analyzed in the ferret model, A/Ohio/09/2015 and another H1N1v virus, A/Iowa/39/2015, as well as A/California/07/2009, replicated efficiently in the respiratory tract of ferrets. The two H1N1v viruses transmitted efficiently among cohoused ferrets, but respiratory droplet transmission studies showed that A/California/07/2009 transmitted through the air more efficiently. Preexisting immunity to A/California/07/2009 did not fully protect ferrets from challenge with A/Ohio/09/2015. IMPORTANCE Human infections with classical swine influenza A(H1N1) viruses that circulate in pigs continue to occur in the United States following exposure to swine. To

Novel reassortant of swine influenza H1N2 virus in Germany.

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Zell, Roland; Motzke, Susann; Krumbholz, Andi; Wutzler, Peter; Herwig, Volker; Dürrwald, Ralf

2008-01-01

European porcine H1N2 influenza viruses arose after multiple reassortment steps involving a porcine influenza virus with avian-influenza-like internal segments and human H1N1 and H3N2 viruses in 1994. In Germany, H1N2 swine influenza viruses first appeared in 2000. Two German H1N2 swine influenza virus strains isolated from pigs with clinical symptoms of influenza are described. They were characterized by the neutralization test, haemagglutination inhibition (HI) test and complete sequencing of the viral genomes. The data demonstrate that these viruses represent a novel H1N2 reassortant. The viruses showed limited neutralization by sera raised against heterologous A/sw/Bakum/1,832/00-like H1N2 viruses. Sera pools from recovered pigs showed a considerably lower HI reaction, indicative of diagnostic difficulties in using the HI test to detect these viruses with A/sw/Bakum/1,832/00-like H1N2 antigens. Genome sequencing revealed the novel combination of the human-like HAH1 gene of European porcine H1N2 influenza viruses and the NAN2 gene of European porcine H3N2 viruses.

Genetic and biological characterisation of an avian-like H1N2 swine influenza virus generated by reassortment of circulating avian-like H1N1 and H3N2 subtypes in Denmark.

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Trebbien, Ramona; Bragstad, Karoline; Larsen, Lars Erik; Nielsen, Jens; Bøtner, Anette; Heegaard, Peter M H; Fomsgaard, Anders; Viuff, Birgitte; Hjulsager, Charlotte Kristiane

2013-09-18

The influenza A virus subtypes H1N1, H1N2 and H3N2 are the most prevalent subtypes in swine. In 2003, a reassorted H1N2 swine influenza virus (SIV) subtype appeared and became prevalent in Denmark. In the present study, the reassortant H1N2 subtype was characterised genetically and the infection dynamics compared to an "avian-like" H1N1 virus by an experimental infection study. Sequence analyses were performed of the H1N2 virus. Two groups of pigs were inoculated with the reassortant H1N2 virus and an "avian-like" H1N1 virus, respectively, followed by inoculation with the opposite subtype four weeks later. Measurements of HI antibodies and acute phase proteins were performed. Nasal virus excretion and virus load in lungs were determined by real-time RT-PCR. The phylogenetic analysis revealed that the reassorted H1N2 virus contained a European "avian-like" H1-gene and a European "swine-like" N2-gene, thus being genetically distinct from most H1N2 viruses circulating in Europe, but similar to viruses reported in 2009/2010 in Sweden and Italy. Sequence analyses of the internal genes revealed that the reassortment probably arose between circulating Danish "avian-like" H1N1 and H3N2 SIVs. Infected pigs developed cross-reactive antibodies, and increased levels of acute phase proteins after inoculations. Pigs inoculated with H1N2 exhibited nasal virus excretion for seven days, peaking day 1 after inoculation two days earlier than H1N1 infected pigs and at a six times higher level. The difference, however, was not statistically significant. Pigs euthanized on day 4 after inoculation, had a high virus load in all lung lobes. After the second inoculation, the nasal virus excretion was minimal. There were no clinical sign except elevated body temperature under the experimental conditions. The "avian-like" H1N2 subtype, which has been established in the Danish pig population at least since 2003, is a reassortant between circulating swine "avian-like" H1N1 and H3N2. The Danish

Swine Influenza (Swine Flu) in Pigs

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... Address What's this? Submit What's this? Submit Button Influenza Types Seasonal Avian Swine Variant Pandemic Other Key Facts about Swine Influenza (Swine Flu) in Pigs Language: English (US) Español ...

Novel reassortant influenza A(H1N2) virus derived from A(H1N1)pdm09 virus isolated from swine, Japan, 2012.

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Kobayashi, Miho; Takayama, Ikuyo; Kageyama, Tsutomu; Tsukagoshi, Hiroyuki; Saitoh, Mika; Ishioka, Taisei; Yokota, Yoko; Kimura, Hirokazu; Tashiro, Masato; Kozawa, Kunihisa

2013-12-01

We isolated a novel influenza virus A(H1N2) strain from a pig on January 13, 2012, in Gunma Prefecture, Japan. Phylogenetic analysis showed that the strain was a novel type of double-reassortant virus derived from the swine influenza virus strains H1N1pdm09 and H1N2, which were prevalent in Gunma at that time.

Human temperatures for syndromic surveillance in the emergency department: data from the autumn wave of the 2009 swine flu (H1N1) pandemic and a seasonal influenza outbreak.

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Bordonaro, Samantha F; McGillicuddy, Daniel C; Pompei, Francesco; Burmistrov, Dmitriy; Harding, Charles; Sanchez, Leon D

2016-03-09

The emergency department (ED) increasingly acts as a gateway to the evaluation and treatment of acute illnesses. Consequently, it has also become a key testing ground for systems that monitor and identify outbreaks of disease. Here, we describe a new technology that automatically collects body temperatures during triage. The technology was tested in an ED as an approach to monitoring diseases that cause fever, such as seasonal flu and some pandemics. Temporal artery thermometers that log temperature measurements were placed in a Boston ED and used for initial triage vital signs. Time-stamped measurements were collected from the thermometers to investigate the performance a real-time system would offer. The data were summarized in terms of rates of fever (temperatures ≥100.4 °F [≥38.0 °C]) and were qualitatively compared with regional disease surveillance programs in Massachusetts. From September 2009 through August 2011, 71,865 body temperatures were collected and included in our analysis, 2073 (2.6 %) of which were fevers. The period of study included the autumn-winter wave of the 2009-2010 H1N1 (swine flu) pandemic, during which the weekly incidence of fever reached a maximum of 5.6 %, as well as the 2010-2011 seasonal flu outbreak, during which the maximum weekly incidence of fever was 6.6 %. The periods of peak fever rates corresponded with the periods of regionally elevated flu activity. Temperature measurements were monitored at triage in the ED over a period of 2 years. The resulting data showed promise as a potential surveillance tool for febrile disease that could complement current disease surveillance systems. Because temperature can easily be measured by non-experts, it might also be suitable for monitoring febrile disease activity in schools, workplaces, and transportation hubs, where many traditional syndromic indicators are impractical. However, the system's validity and generalizability should be evaluated in additional years and

Public views of the uk media and government reaction to the 2009 swine flu pandemic

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Smith Emily

2010-11-01

Full Text Available Abstract Background The first cases of influenza A/H1N1 (swine flu were confirmed in the UK on 27th April 2009, after a novel virus first identified in Mexico rapidly evolved into a pandemic. The swine flu outbreak was the first pandemic in more than 40 years and for many, their first encounter with a major influenza outbreak. This study examines public understandings of the pandemic, exploring how people deciphered the threat and perceived they could control the risks. Methods Purposive sampling was used to recruit seventy three people (61 women and 12 men to take part in 14 focus group discussions around the time of the second wave in swine flu cases. Results These discussions showed that there was little evidence of the public over-reacting, that people believed the threat of contracting swine flu was inevitable, and that they assessed their own self-efficacy for protecting against it to be low. Respondents assessed a greater risk to their health from the vaccine than from the disease. Such findings could have led to apathy about following the UK Governments recommended health protective behaviours, and a sub-optimal level of vaccine uptake. More generally, people were confused about the difference between seasonal influenza and swine flu and their vaccines. Conclusions This research suggests a gap in public understandings which could hinder attempts to communicate about novel flu viruses in the future. There was general support for the government's handling of the pandemic, although its public awareness campaign was deemed ineffectual as few people changed their current hand hygiene practices. There was less support for the media who were deemed to have over-reported the swine flu pandemic.

Crying wolf? Biosecurity and metacommunication in the context of the 2009 swine flu pandemic.

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Nerlich, Brigitte; Koteyko, Nelya

2012-07-01

This article explores how the 2009 pandemic of swine flu (H1N1) intersected with issues of biosecurity in the context of an increasing entanglement between the spread of disease and the spread of information. Drawing on research into metacommunication, the article studies the rise of communication about ways in which swine flu was communicated, both globally and locally, during the pandemic. It examines and compares two corpora of texts, namely UK newspaper articles and blogs, written between 28 March and 11 June 2009, that is, the period from the start of the outbreak till the WHO announcement of the pandemic. Findings show that the interaction between traditional and digital media as well as the interaction between warnings about swine flu and previous warnings about other epidemics contributed to a heightened discourse of blame and counter-blame but also, more surprisingly, self-blame and reflections about the role the media in pandemic communication. The consequences of this increase in metacommunication for research into crisis communication are explored. Copyright © 2011 Elsevier Ltd. All rights reserved.

Protection of guinea pigs by vaccination with a recombinant swinepox virus co-expressing HA1 genes of swine H1N1 and H3N2 influenza viruses.

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Xu, Jiarong; Yang, Deji; Huang, Dongyan; Xu, Jiaping; Liu, Shichao; Lin, Huixing; Zhu, Haodan; Liu, Bao; Lu, Chengping

2013-03-01

Swine influenza (SI) is an acute respiratory infectious disease of swine caused by swine influenza virus (SIV). SIV is not only an important respiratory pathogen in pigs but also a potent threat to human health. Here, we report the construction of a recombinant swinepox virus (rSPV/H3-2A-H1) co-expressing hemagglutinin (HA1) of SIV subtypes H1N1 and H3N2. Immune responses and protection efficacy of the rSPV/H3-2A-H1 were evaluated in guinea pigs. Inoculation of rSPV/H3-2A-H1 yielded neutralizing antibodies against SIV H1N1 and H3N2. The IFN-γ and IL-4 concentrations in the supernatant of lymphocytes stimulated with purified SIV HA1 antigen were significantly higher (P guinea pigs against SIV H1N1 or H3N2 challenge was observed. No SIV shedding was detected from guinea pigs vaccinated with rSPV/H3-2A-H1 after challenge. Most importantly, the guinea pigs immunized with rSPV/H3-2A-H1 did not show gross and micrographic lung lesions. However, the control guinea pigs experienced distinct gross and micrographic lung lesions at 7 days post-challenge. Our data suggest that the recombinant swinepox virus encoding HA1 of SIV H1N1 and H3N2 might serve as a promising candidate vaccine for protection against SIV H1N1 and H3N2 infections.

Bilateral Pulmonary Thromboembolism: An Unusual Presentation of Infection with Influenza A (H1N1 Virus

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Parviz Saleh

2010-06-01

Full Text Available AbstractSwine flue is a highly contagious acute respiratory diseasecaused by a subtype of influenza A virus. Herein we presentthree patients with H1N1 infection complicated with pulmonarythromboembolism. The patients had chest pain and unexplaineddyspnea. Imaging studies showed bilateral hilar predominance.Computed tomographic angiography confirmed bilateral thromboembolism(an unusual presentation of H1N1 infection. We didnot find any predisposing factor including endothelial damage,stasis, or hypercoagulable state in these patients. They did notreceive any medication. After anticoagulation and treatment withoseltamivir, all the patients were discharged in good condition.To the best of our knowledge bilateral pulmonary thromboembolismhas not been reported in English language literature inpatients with swine flu infection. Appropriate diagnosis andtreatment will be life saving in this condition.Iran J Med Sci 2010; 35(2: 149-153.

Genetic and biological characterisation of an avian-like H1N2 swine influenza virus generated by reassortment of circulating avian-like H1N1 and H3N2 subtypes in Denmark

DEFF Research Database (Denmark)

Trebbien, Ramona; Bragstad, Karoline; Larsen, Lars Erik

2013-01-01

BACKGROUND: The influenza A virus subtypes H1N1, H1N2 and H3N2 are the most prevalent subtypes in swine. In 2003, a reassorted H1N2 swine influenza virus (SIV) subtype appeared and became prevalent in Denmark. In the present study, the reassortant H1N2 subtype was characterised genetically...... and the infection dynamics compared to an “avian-like” H1N1 virus by an experimental infection study. METHODS: Sequence analyses were performed of the H1N2 virus. Two groups of pigs were inoculated with the reassortant H1N2 virus and an “avian-like” H1N1 virus, respectively, followed by inoculation...... with the opposite subtype four weeks later. Measurements of HI antibodies and acute phase proteins were performed. Nasal virus excretion and virus load in lungs were determined by real-time RT-PCR. RESULTS: The phylogenetic analysis revealed that the reassorted H1N2 virus contained a European “avian-like” H1-gene...

A novel monoclonal antibody effective against lethal challenge with swine-lineage and 2009 pandemic H1N1 influenza viruses in mice

Science.gov (United States)

The HA protein of the 2009 pandemic H1N1viruses (14 H1N1pdm) is antigenically closely related to the HA of classical North American swine H1N1 influenza viruses (cH1N1). Since 1998, through reassortment and incorporation of HA genes from human H3N2 and H1N1 influenza viruses, swine influenza strains...

The first Swedish H1N2 swine influenza virus isolate represents an uncommon reassortant

OpenAIRE

Renström Lena HM; Isaksson Mats; Berg Mikael; Zohari Siamak; Widén Frederik; Metreveli Giorgi; Bálint Ádám; Wallgren Per; Belák Sándor; Segall Thomas; Kiss István

2009-01-01

Abstract The European swine influenza viruses (SIVs) show considerable diversity comprising different types of H1N1, H3N2, and H1N2 strains. The intensifying full genome sequencing efforts reveal further reassortants within these subtypes. Here we report the identification of an uncommon reassortant variant of H1N2 subtype influenza virus isolated from a pig in a multisite herd where H1N2 swine influenza was diagnosed for the first time in Sweden during the winter of 2008-2009. The majority o...

How Does Influenza A (H1N1 Infection Proceed in Allogeneic Stem Cell Transplantation Recipients?

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Sinem Civriz Bozdağ

2012-03-01

Full Text Available Clinical course of H1N1 infection in Allogeneic Hematopoietic Stem Cell Transplantation (AHSCT patients is contraversial. We report three AHSCT patients who were infected with Influenza A/H1N1 infection. All of the patients were diagnosed with different hematological diagnosis and were at different stages of transplantation.All of them were treated with oseltamivir,zanamivir was switched with oseltamivir in one patient. All of the three patients were survived without any complication. Swine flu, can display with different courses and progress with bacterial or other viral infections in immunsupressed patients.

Specific Inhibitory Effect of κ-Carrageenan Polysaccharide on Swine Pandemic 2009 H1N1 Influenza Virus.

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Qiang Shao

Full Text Available The 2009 influenza A H1N1 pandemic placed unprecedented demands on antiviral drug resources and the vaccine industry. Carrageenan, an extractive of red algae, has been proven to inhibit infection and multiplication of various enveloped viruses. The aim of this study was to examine the ability of κ-carrageenan to inhibit swine pandemic 2009 H1N1 influenza virus to gain an understanding of antiviral ability of κ-carrageenan. It was here demonstrated that κ-carrageenan had no cytotoxicity at concentrations below 1000 μg/ml. Hemagglutination, 50% tissue culture infectious dose (TCID50 and cytopathic effect (CPE inhibition assays showed that κ-carrageenan inhibited A/Swine/Shandong/731/2009 H1N1 (SW731 and A/California/04/2009 H1N1 (CA04 replication in a dose-dependent fashion. Mechanism studies show that the inhibition of SW731 multiplication and mRNA expression was maximized when κ-carrageenan was added before or during adsorption. The result of Hemagglutination inhibition assay indicate that κ-carrageenan specifically targeted HA of SW731 and CA04, both of which are pandemic H1N/2009 viruses, without effect on A/Pureto Rico/8/34 H1N1 (PR8, A/WSN/1933 H1N1 (WSN, A/Swine/Beijing/26/2008 H1N1 (SW26, A/Chicken/Shandong/LY/2008 H9N2 (LY08, and A/Chicken/Shandong/ZB/2007 H9N2 (ZB07 viruses. Immunofluorescence assay and Western blot showed that κ-carrageenan also inhibited SW731 protein expression after its internalization into cells. These results suggest that κ-carrageenan can significantly inhibit SW731 replication by interfering with a few replication steps in the SW731 life cycles, including adsorption, transcription, and viral protein expression, especially interactions between HA and cells. In this way, κ-carrageenan might be a suitable alternative approach to therapy meant to address anti-IAV, which contains an HA homologous to that of SW731.

H1N1 Swine Influenza Viruses Differ from Avian Precursors by a Higher pH Optimum of Membrane Fusion.

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Baumann, Jan; Kouassi, Nancy Mounogou; Foni, Emanuela; Klenk, Hans-Dieter; Matrosovich, Mikhail

2016-02-01

The H1N1 Eurasian avian-like swine (EAsw) influenza viruses originated from an avian H1N1 virus. To characterize potential changes in the membrane fusion activity of the hemagglutinin (HA) during avian-to-swine adaptation of the virus, we studied EAsw viruses isolated in the first years of their circulation in pigs and closely related contemporary H1N1 viruses of wild aquatic birds. Compared to the avian viruses, the swine viruses were less sensitive to neutralization by lysosomotropic agent NH4Cl in MDCK cells, had a higher pH optimum of hemolytic activity, and were less stable at acidic pH. Eight amino acid substitutions in the HA were found to separate the EAsw viruses from their putative avian precursor; four substitutions-T492S, N722D, R752K, and S1132F-were located in the structural regions of the HA2 subunit known to play a role in acid-induced conformational transition of the HA. We also studied low-pH-induced syncytium formation by cell-expressed HA proteins and found that the HAs of the 1918, 1957, 1968, and 2009 pandemic viruses required a lower pH for fusion induction than did the HA of a representative EAsw virus. Our data show that transmission of an avian H1N1 virus to pigs was accompanied by changes in conformational stability and fusion promotion activity of the HA. We conclude that distinctive host-determined fusion characteristics of the HA may represent a barrier for avian-to-swine and swine-to-human transmission of influenza viruses. Continuing cases of human infections with zoonotic influenza viruses highlight the necessity to understand which viral properties contribute to interspecies transmission. Efficient binding of the HA to cellular receptors in a new host species is known to be essential for the transmission. Less is known about required adaptive changes in the membrane fusion activity of the HA. Here we show that adaptation of an avian influenza virus to pigs in Europe in 1980s was accompanied by mutations in the HA, which decreased

The origin of the PB1 segment of swine influenza A virus subtype H1N2 determines viral pathogenicity in mice.

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Metreveli, Giorgi; Gao, Qinshan; Mena, Ignacio; Schmolke, Mirco; Berg, Mikael; Albrecht, Randy A; García-Sastre, Adolfo

2014-08-08

Swine appear to be a key species in the generation of novel human influenza pandemics. Previous pandemic viruses are postulated to have evolved in swine by reassortment of avian, human, and swine influenza viruses. The human pandemic influenza viruses that emerged in 1957 and 1968 as well as swine viruses circulating since 1998 encode PB1 segments derived from avian influenza viruses. Here we investigate the possible role in viral replication and virulence of the PB1 gene segments present in two swine H1N2 influenza A viruses, A/swine/Sweden/1021/2009(H1N2) (sw 1021) and A/swine/Sweden/9706/2010(H1N2) (sw 9706), where the sw 1021 virus has shown to be more pathogenic in mice. By using reverse genetics, we swapped the PB1 genes of these two viruses. Similar to the sw 9706 virus, chimeric sw 1021 virus carrying the sw 9706 PB1 gene was not virulent in mice. In contrast, replacement of the PB1 gene of the sw 9706 virus by that from sw 1021 virus resulted in increased pathogenicity. Our study demonstrated that differences in virulence of swine influenza virus subtype H1N2 are attributed at least in part to the PB1 segment. Copyright © 2014 Elsevier B.V. All rights reserved.

The first Swedish H1N2 swine influenza virus isolate represents an uncommon reassortant

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Renström Lena HM

2009-10-01

Full Text Available Abstract The European swine influenza viruses (SIVs show considerable diversity comprising different types of H1N1, H3N2, and H1N2 strains. The intensifying full genome sequencing efforts reveal further reassortants within these subtypes. Here we report the identification of an uncommon reassortant variant of H1N2 subtype influenza virus isolated from a pig in a multisite herd where H1N2 swine influenza was diagnosed for the first time in Sweden during the winter of 2008-2009. The majority of the European H1N2 swine influenza viruses described so far possess haemagglutinin (HA of the human-like H1N2 SIV viruses and the neuraminidase (NA of either the European H1N2 or H3N2 SIV-like viruses. The Swedish isolate has an avian-like SIV HA and a H3N2 SIV-like NA, which is phylogenetically more closely related to H3N2 SIV NAs from isolates collected in the early '80s than to the NA of H3N2 origin of the H1N2 viruses isolated during the last decade, as depicted by some German strains, indicative of independent acquisition of the NA genes for these two types of reassortants. The internal genes proved to be entirely of avian-like SIV H1N1 origin. The prevalence of this SIV variant in pig populations needs to be determined, as well as the suitability of the routinely used laboratory reagents to analyze this strain. The description of this H1N2 SIV adds further information to influenza epidemiology and supports the necessity of surveillance for influenza viruses in pigs.

The first Swedish H1N2 swine influenza virus isolate represents an uncommon reassortant.

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Bálint, Adám; Metreveli, Giorgi; Widén, Frederik; Zohari, Siamak; Berg, Mikael; Isaksson, Mats; Renström, Lena Hm; Wallgren, Per; Belák, Sándor; Segall, Thomas; Kiss, István

2009-10-28

The European swine influenza viruses (SIVs) show considerable diversity comprising different types of H1N1, H3N2, and H1N2 strains. The intensifying full genome sequencing efforts reveal further reassortants within these subtypes. Here we report the identification of an uncommon reassortant variant of H1N2 subtype influenza virus isolated from a pig in a multisite herd where H1N2 swine influenza was diagnosed for the first time in Sweden during the winter of 2008-2009. The majority of the European H1N2 swine influenza viruses described so far possess haemagglutinin (HA) of the human-like H1N2 SIV viruses and the neuraminidase (NA) of either the European H1N2 or H3N2 SIV-like viruses. The Swedish isolate has an avian-like SIV HA and a H3N2 SIV-like NA, which is phylogenetically more closely related to H3N2 SIV NAs from isolates collected in the early '80s than to the NA of H3N2 origin of the H1N2 viruses isolated during the last decade, as depicted by some German strains, indicative of independent acquisition of the NA genes for these two types of reassortants. The internal genes proved to be entirely of avian-like SIV H1N1 origin. The prevalence of this SIV variant in pig populations needs to be determined, as well as the suitability of the routinely used laboratory reagents to analyze this strain.The description of this H1N2 SIV adds further information to influenza epidemiology and supports the necessity of surveillance for influenza viruses in pigs.

Treatment and Prevention of Pandemic H1N1 Influenza.

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Rewar, Suresh; Mirdha, Dashrath; Rewar, Prahlad

2015-01-01

Swine influenza is a respiratory infection common to pigs worldwide caused by type A influenza viruses, principally subtypes H1N1, H1N2, H2N1, H3N1, H3N2, and H2N3. Swine influenza viruses also can cause moderate to severe illness in humans and affect persons of all age groups. People in close contact with swine are at especially high risk. Until recently, epidemiological study of influenza was limited to resource-rich countries. The World Health Organization declared an H1N1 pandemic on June 11, 2009, after more than 70 countries reported 30,000 cases of H1N1 infection. In 2015, incidence of swine influenza increased substantially to reach a 5-year high. In India in 2015, 10,000 cases of swine influenza were reported with 774 deaths. The Centers for Disease Control and Prevention recommend real-time polymerase chain reaction as the method of choice for diagnosing H1N1. Antiviral drugs are the mainstay of clinical treatment of swine influenza and can make the illness milder and enable the patient to feel better faster. Antiviral drugs are most effective when they are started within the first 48 hours after the clinical signs begin, although they also may be used in severe or high-risk cases first seen after this time. The Centers for Disease Control and Prevention recommends use of oseltamivir (Tamiflu, Genentech) or zanamivir (Relenza, GlaxoSmithKline). Prevention of swine influenza has 3 components: prevention in swine, prevention of transmission to humans, and prevention of its spread among humans. Because of limited treatment options, high risk for secondary infection, and frequent need for intensive care of individuals with H1N1 pneumonia, environmental control, including vaccination of high-risk populations and public education are critical to control of swine influenza out breaks. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Genetic characterization of H1N2 swine influenza virus isolated in China and its pathogenesis and inflammatory responses in mice.

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Zhang, Yan; Wang, Nan; Cao, Jiyue; Chen, Huanchun; Jin, Meilin; Zhou, Hongbo

2013-09-01

In 2009, two H1N2 influenza viruses were isolated from trachea swabs of pigs in Hubei in China. We compared these sequences with the other 18 complete genome sequences of swine H1N2 isolates from China during 2004 to 2010 and undertook extensive analysis of their evolutionary patterns. Six different genotypes - two reassortants between triple reassortant (TR) H3N2 and classical swine (CS) H1N1 virus, three reassortants between TR H1N2, Eurasian avian-like H1N1 swine virus and H9N2 swine virus, and one reassortant between H1N1, H3N2 human virus and CS H1N1 virus - were observed in these 20 swine H1N2 isolates. The TR H1N2 swine virus is the predominant genotype, and the two Hubei H1N2 isolates were located in this cluster. We also used a mouse model to examine the pathogenesis and inflammatory responses of the two isolates. The isolates replicated efficiently in the lung, and exhibited a strong inflammatory response, serious pathological changes and mortality in infected mice. Given the role that swine can play as putative "genetic mixing vessels" and the observed transmission of TR H1N2 in ferrets, H1N2 influenza surveillance in pigs should be increased to minimize the potential threat to public health.

Isolation and genetic characterization of avian-like H1N1 and novel ressortant H1N2 influenza viruses from pigs in China.

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Yu, Hai; Zhang, Peng-Chao; Zhou, Yan-Jun; Li, Guo-Xin; Pan, Jie; Yan, Li-Ping; Shi, Xiao-Xiao; Liu, Hui-Li; Tong, Guang-Zhi

2009-08-21

As pigs are susceptible to both human and avian influenza viruses, they have been proposed to be intermediate hosts or mixing vessels for the generation of pandemic influenza viruses through reassortment or adaptation to the mammalian host. In this study, we reported avian-like H1N1 and novel ressortant H1N2 influenza viruses from pigs in China. Homology and phylogenetic analyses showed that the H1N1 virus (A/swine/Zhejiang/1/07) was closely to avian-like H1N1 viruses and seemed to be derived from the European swine H1N1 viruses, which was for the first time reported in China; and the two H1N2 viruses (A/swine/Shanghai/1/07 and A/swine/Guangxi/13/06) were novel ressortant H1N2 influenza viruses containing genes from the classical swine (HA, NP, M and NS), human (NA and PB1) and avian (PB2 and PA) lineages, which indicted that the reassortment among human, avian, and swine influenza viruses had taken place in pigs in China and resulted in the generation of new viruses. The isolation of avian-like H1N1 influenza virus originated from the European swine H1N1 viruses, especially the emergence of two novel ressortant H1N2 influenza viruses provides further evidence that pigs serve as intermediate hosts or "mixing vessels", and swine influenza virus surveillance in China should be given a high priority.

Evaluation of the Cepheid Xpert Flu Assay for rapid identification and differentiation of influenza A, influenza A 2009 H1N1, and influenza B viruses.

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Novak-Weekley, S M; Marlowe, E M; Poulter, M; Dwyer, D; Speers, D; Rawlinson, W; Baleriola, C; Robinson, C C

2012-05-01

The Xpert Flu Assay cartridge is a next-generation nucleic acid amplification system that provides multiplexed PCR detection of the influenza A, influenza A 2009 H1N1, and influenza B viruses in approximately 70 min with minimal hands-on time. Six laboratories participated in a clinical trial comparing the results of the new Cepheid Xpert Flu Assay to those of culture or real-time PCR with archived and prospectively collected nasal aspirate-wash (NA-W) specimens and nasopharyngeal (NP) swabs from children and adults. Discrepant results were resolved by DNA sequence analysis. After discrepant-result analysis, the sensitivities of the Xpert Flu Assay for prospective NA-W specimens containing the influenza A, influenza A 2009 H1N1, and influenza B viruses compared to those of culture were 90.0%, 100%, and 100%, respectively, while the sensitivities of the assay for prospective NP swabs compared to those of culture were 100%, 100%, and 100%, respectively. The sensitivities of the Xpert Flu Assay for archived NA-W specimens compared to those of Gen-Probe ProFlu+ PCR for the influenza A, influenza A 2009 H1N1, and influenza B viruses were 99.4%, 98.4%, and 100%, respectively, while the sensitivities of the Xpert Flu Assay for archived NP swabs compared to those of ProFlu+ were 98.1%, 100%, and 93.8%, respectively. The sensitivities of the Xpert Flu Assay with archived NP specimens compared to those of culture for the three targets were 97.5%, 100%, and 93.8%, respectively. We conclude that the Cepheid Xpert Flu Assay is an accurate and rapid method that is suitable for on-demand testing for influenza viral infection.

Multiplex RT-PCR assay for differentiating European swine influenza virus subtypes H1N1, H1N2 and H3N2.

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Chiapponi, Chiara; Moreno, Ana; Barbieri, Ilaria; Merenda, Marianna; Foni, Emanuela

2012-09-01

In Europe, three major swine influenza viral (SIV) subtypes (H1N1, H1N2 and H3N2) have been isolated in pigs. Developing a test that is able to detect and identify the subtype of the circulating strain rapidly during an outbreak of respiratory disease in the pig population is of essential importance. This study describes two multiplex RT-PCRs which distinguish the haemagglutinin (HA) gene and the neuraminidase (NA) gene of the three major subtypes of SIV circulating in Europe. The HA PCR was able to identify the lineage (avian or human) of the HA of H1 subtypes. The analytical sensitivity of the test, considered to be unique, was assessed using three reference viruses. The detection limit corresponded to 1×10(-1) TCID(50)/200μl for avian-like H1N1, 1×10(0) TCID(50)/200μl for human-like H1N2 and 1×10(1) TCID(50)/200μl for H3N2 SIV. The multiplex RT-PCR was first carried out on a collection of 70 isolated viruses showing 100% specificity and then on clinical samples, from which viruses had previously been isolated, resulting in an 89% positive specificity of the viral subtype. Finally, the test was able to identify the viral subtype correctly in 56% of influenza A positive samples, from which SIV had not been isolated previously. It was also possible to identify mixed viral infections and the circulation of a reassortant strain before performing genomic studies. Copyright © 2012 Elsevier B.V. All rights reserved.

Adaptive evolution during the establishment of European avian-like H1N1 influenza A virus in swine.

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Joseph, Udayan; Vijaykrishna, Dhanasekaran; Smith, Gavin J D; Su, Yvonne C F

2018-04-01

An H1N1 subtype influenza A virus with all eight gene segments derived from wild birds (including mallards), ducks and chickens, caused severe disease outbreaks in swine populations in Europe beginning in 1979 and successfully adapted to form the European avian-like swine (EA-swine) influenza lineage. Genes of the EA-swine lineage that are clearly segregated from its closest avian relatives continue to circulate in swine populations globally and represent a unique opportunity to study the adaptive process of an avian-to-mammalian cross-species transmission. Here, we used a relaxed molecular clock model to test whether the EA-swine virus originated through the introduction of a single avian ancestor as an entire genome, followed by an analysis of host-specific selection pressures among different gene segments. Our data indicated independent introduction of gene segments via transmission of avian viruses into swine followed by reassortment events that occurred at least 1-4 years prior to the EA-swine outbreak. All EA-swine gene segments exhibit greater selection pressure than avian viruses, reflecting both adaptive pressures and relaxed selective constraints that are associated with host switching. Notably, we identified key amino acid mutations in the viral surface proteins (H1 and N1) that play a role in adaptation to new hosts. Following the establishment of EA-swine lineage, we observed an increased frequency of intrasubtype reassortment of segments compared to the earlier strains that has been associated with adaptive amino acid replacements, disease severity and vaccine escape. Taken together, our study provides key insights into the adaptive changes in viral genomes following the transmission of avian influenza viruses to swine and the early establishment of the EA-swine lineage.

Transmission dynamics of pandemic influenza A(H1N1)pdm09 virus in humans and swine in backyard farms in Tumbes, Peru.

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Tinoco, Yeny O; Montgomery, Joel M; Kasper, Mathew R; Nelson, Martha I; Razuri, Hugo; Guezala, Maria C; Azziz-Baumgartner, Eduardo; Widdowson, Marc-Alain; Barnes, John; Gilman, Robert H; Bausch, Daniel G; Gonzalez, Armando E

2016-01-01

We aimed to determine the frequency of pH1N1 transmission between humans and swine on backyard farms in Tumbes, Peru. Two-year serial cross-sectional study comprising four sampling periods: March 2009 (pre-pandemic), October 2009 (peak of the pandemic in Peru), April 2010 (1st post-pandemic period), and October 2011 (2nd post-pandemic period). Backyard swine serum, tracheal swabs, and lung sample were collected during each sampling period. We assessed current and past pH1N1 infection in swine through serological testing, virus culture, and RT-PCR and compared the results with human incidence data from a population-based active surveillance cohort study in Peru. Among 1303 swine sampled, the antibody prevalence to pH1N1 was 0% pre-pandemic, 8% at the peak of the human pandemic (October 2009), and 24% in April 2010 and 1% in October 2011 (post-pandemic sampling periods). Trends in swine seropositivity paralleled those seen in humans in Tumbes. The pH1N1 virus was isolated from three pigs during the peak of the pandemic. Phylogenetic analysis revealed that these viruses likely represent two separate human-to-swine transmission events in backyard farm settings. Our findings suggest that human-to-swine pH1N1 transmission occurred during the pandemic among backyard farms in Peru, emphasizing the importance of interspecies transmission in backyard pig populations. Continued surveillance for influenza viruses in backyard farms is warranted. © 2015 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

A rapid method for assessing social versus independent interest in health issues: a case study of 'bird flu' and 'swine flu'.

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Bentley, R Alexander; Ormerod, Paul

2010-08-01

Effective communication strategies regarding health issues are affected by the way in which the public obtain their knowledge, particularly whether people become interested independently, or through their social networks. This is often investigated through localized ethnography or surveys. In rapidly-evolving situations, however, there may also be a need for swift, case-specific assessment as a guide to initial strategy development. With this aim, we analyze real-time online data, provided by the new 'Google Trends' tool, concerning Internet search frequency for health-related issues. To these data we apply a simple model to characterise the effective degree of social transmission versus decisions made individually. As case examples, we explore two rapidly-evolved issues, namely the world-wide interest in avian influenza, or 'bird flu', in 2005, and in H1N1, or 'swine flu', from late April to early May 2009. The 2005 'bird flu' scare demonstrated almost pure imitation for two months initially, followed by a spike of independent decision that corresponded with an announcement by US president George Bush. For 'swine flu' in 2009, imitation was the more prevalent throughout. Overall, the results show how interest in health scares can spread primarily by social means, and that engaging more independent decisions at the population scale may require a dramatic announcement to push a populace over the 'tipping point'. Copyright 2010 Elsevier Ltd. All rights reserved.

Modeling of the influence of humidity on H1N1 flu in China

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PEI, Y.; Tian, H.; Xu, B.

2015-12-01

In 2009, a heavy Flu hit the whole world. It was caused by the virus H1N1. The influenza first broke out in Mexico in March and the United States in April, 2009. The World Health Organization (WHO) announced that the H1N1 influenza became pandemic, alert to a warning phase of six. By the end of 2011, 181302 H1N1 cases were reported in mainland China. To improve our understanding on the impact of environmental factors on the disease transmission, we constructed an SIR (Susceptible - Infectious - Recovered) model incorporating environmental factors. It was found that the absolute humidity was a dominant environmental factor. The study interpolated the humidity data monitored with 340 weather stations from 1951 to 2011 in mainland China. First, the break point of the trend for the absolutely humidity was detected by the BFAST (Break For Additive Season and Trend) method. Then, the SIR model with and without the absolutely humidity incorporated in the model was built and tested. Finally, the results with the two scenarios were compared. Results indicate that lower absolutely humidity may promote the transmission of the H1N1 cases. The calculated basic reproductive number ranges from 1.65 to 3.66 with a changing absolute humidity. This is consistent with the former study result with basic reproductive number ranging from 2.03 to 4.18. The average recovery duration was estimated to be 5.7 days. The average duration to get immunity from the influenza is 399.02 days. A risk map is also produced to illustrate the model results.

‘Presenting CXR phenotype of H1N1’ flu compared with contemporaneous non-H1N1, community acquired pneumonia, during pandemic and post-pandemic outbreaks’

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Minns, F.C.; Nimhuineachain, A; Beek, E.J.R. van; Ritchie, G.; Hill, A.; Murchison, J.T.

2015-01-01

Highlights: • Patients with H1N1 pneumonia demonstrated more opacified zones on chest x-ray than patients with non-H1N1 pneumonias. • A particular ‘phenotype’ of chest x-ray changes was identified in H1N1 patients. • This H1N1 ‘phenotype’ was the same for the two evaluated ‘flu seasons, during both pandemic and post pandemic stages. - Abstract: Aims: To review, phenotype and assess potential prognostic value of initial chest X-ray findings in patients with H1N1 influenza during seasonal outbreaks of 2009 and 2010, in comparison with non-H1N1, community acquired pneumonia (CAP). Methods: We retrospectively identified 72 patients admitted to hospital with pneumonia during the seasons of 2009 and 2010. H1N1 cases were confirmed by virology PCR. Presenting chest X-rays were jointly read by 2 radiologists, who were ‘blinded’ to further patient details and divided into 6 zones. Total number of opacified zones, the pattern and distribution of changes and length of hospital stay were recorded. Results: Patients with H1N1 demonstrated more opacified zones (mean of 2.9 compared with 2.0; p = 0.006), which were bilateral in two-thirds compared with a quarter of those with non-H1N1 CAP (p = 0.001). H1N1 radiographs were more likely to be ‘patchy’ versus ‘confluent’ changes of non-H1N1 CAP (p = 0.03) and more often demonstrated peripheral distribution (p = 0.01). H1N1 patients tended to stay in hospital longer (not significant; p = 0.08). A positive correlation existed between number of affected zones and length of inpatient stay, which was statistically significant for the cohorts combined (p = 0.02). The findings were the same for the two evaluated seasons. Conclusion: H1N1 patients demonstrated more extensive disease, which was more likely bilateral, ‘patchy’, and peripheral in distribution. With increasing global cases of H1N1, knowledge of the typical findings of the H1N1 presenting chest X-ray may assist with early triage of patients

‘Presenting CXR phenotype of H1N1’ flu compared with contemporaneous non-H1N1, community acquired pneumonia, during pandemic and post-pandemic outbreaks’

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Minns, F.C., E-mail: Fiona.Minns@nhslothian.scot.nhs.uk [Department of Radiology, New Royal Infirmary Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA (United Kingdom); Nimhuineachain, A, E-mail: draideen@gmail.com [Department of Radiology, New Royal Infirmary Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA (United Kingdom); Beek, E.J.R. van, E-mail: Edwin-vanbeek@ed.ac.uk [Clinical Research Imaging Centre, University of Edinburgh, 47 Little France Crescent, Edinburgh, Midlothian EH16 4TJ (United Kingdom); Ritchie, G., E-mail: drgillritchie@hotmail.com [Department of Radiology, New Royal Infirmary Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA (United Kingdom); Hill, A., E-mail: adam.hill318@nhs.net [Department of Respiratory Medicine, New Royal Infirmary, Edinburgh (United Kingdom); Murchison, J.T., E-mail: john.murchison@nhslothian.scot.nhs.uk [Department of Radiology, New Royal Infirmary Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA (United Kingdom)

2015-09-15

Highlights: • Patients with H1N1 pneumonia demonstrated more opacified zones on chest x-ray than patients with non-H1N1 pneumonias. • A particular ‘phenotype’ of chest x-ray changes was identified in H1N1 patients. • This H1N1 ‘phenotype’ was the same for the two evaluated ‘flu seasons, during both pandemic and post pandemic stages. - Abstract: Aims: To review, phenotype and assess potential prognostic value of initial chest X-ray findings in patients with H1N1 influenza during seasonal outbreaks of 2009 and 2010, in comparison with non-H1N1, community acquired pneumonia (CAP). Methods: We retrospectively identified 72 patients admitted to hospital with pneumonia during the seasons of 2009 and 2010. H1N1 cases were confirmed by virology PCR. Presenting chest X-rays were jointly read by 2 radiologists, who were ‘blinded’ to further patient details and divided into 6 zones. Total number of opacified zones, the pattern and distribution of changes and length of hospital stay were recorded. Results: Patients with H1N1 demonstrated more opacified zones (mean of 2.9 compared with 2.0; p = 0.006), which were bilateral in two-thirds compared with a quarter of those with non-H1N1 CAP (p = 0.001). H1N1 radiographs were more likely to be ‘patchy’ versus ‘confluent’ changes of non-H1N1 CAP (p = 0.03) and more often demonstrated peripheral distribution (p = 0.01). H1N1 patients tended to stay in hospital longer (not significant; p = 0.08). A positive correlation existed between number of affected zones and length of inpatient stay, which was statistically significant for the cohorts combined (p = 0.02). The findings were the same for the two evaluated seasons. Conclusion: H1N1 patients demonstrated more extensive disease, which was more likely bilateral, ‘patchy’, and peripheral in distribution. With increasing global cases of H1N1, knowledge of the typical findings of the H1N1 presenting chest X-ray may assist with early triage of patients

Pandemics in the age of Twitter: content analysis of Tweets during the 2009 H1N1 outbreak.

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Cynthia Chew

Full Text Available BACKGROUND: Surveys are popular methods to measure public perceptions in emergencies but can be costly and time consuming. We suggest and evaluate a complementary "infoveillance" approach using Twitter during the 2009 H1N1 pandemic. Our study aimed to: 1 monitor the use of the terms "H1N1" versus "swine flu" over time; 2 conduct a content analysis of "tweets"; and 3 validate Twitter as a real-time content, sentiment, and public attention trend-tracking tool. METHODOLOGY/PRINCIPAL FINDINGS: Between May 1 and December 31, 2009, we archived over 2 million Twitter posts containing keywords "swine flu," "swineflu," and/or "H1N1." using Infovigil, an infoveillance system. Tweets using "H1N1" increased from 8.8% to 40.5% (R(2 = .788; p<.001, indicating a gradual adoption of World Health Organization-recommended terminology. 5,395 tweets were randomly selected from 9 days, 4 weeks apart and coded using a tri-axial coding scheme. To track tweet content and to test the feasibility of automated coding, we created database queries for keywords and correlated these results with manual coding. Content analysis indicated resource-related posts were most commonly shared (52.6%. 4.5% of cases were identified as misinformation. News websites were the most popular sources (23.2%, while government and health agencies were linked only 1.5% of the time. 7/10 automated queries correlated with manual coding. Several Twitter activity peaks coincided with major news stories. Our results correlated well with H1N1 incidence data. CONCLUSIONS: This study illustrates the potential of using social media to conduct "infodemiology" studies for public health. 2009 H1N1-related tweets were primarily used to disseminate information from credible sources, but were also a source of opinions and experiences. Tweets can be used for real-time content analysis and knowledge translation research, allowing health authorities to respond to public concerns.

Infecção pelo vírus Influenza A (H1N1 de origem suína: como reconhecer, diagnosticar e prevenir How to prevent, recognize and diagnose infection with the swine-origin Influenza A (H1N1 virus in humans

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Alcyone Artioli Machado

2009-05-01

Full Text Available Em março de 2009, houve o início de uma epidemia de gripe no México que, em pouco tempo, levou ao surgimento de casos semelhantes em outros países, alertando as autoridades sanitárias para o risco de uma pandemia. Neste artigo, descrevemos os principais sinais e sintomas da infecção pelo vírus Influenza A (H1N1 de origem suína, as medidas a serem tomadas para os casos suspeitos ou confirmados e como proceder em relação aos contactantes. Comentamos também quais drogas são utilizadas para o tratamento e profilaxia.In March of 2009, a flu epidemic began in Mexico. Shortly thereafter, similar cases appeared in other countries, alerting authorities to the risk of a pandemic. This article details the principal signs and symptoms of infection with the swine-origin Influenza A (H1N1 virus. In addition, the measures to be taken in suspected or confirmed cases are addressed, as are the procedures to follow in relation to contacts. Furthermore, the drugs used in the prophylaxis against and the treatment of infection with the H1N1 virus are described.

Identification of reassortant pandemic H1N1 influenza virus in Korean pigs.

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Han, Jae Yeon; Park, Sung Jun; Kim, Hye Kwon; Rho, Semi; Nguyen, Giap Van; Song, Daesub; Kang, Bo Kyu; Moon, Hyung Jun; Yeom, Min Joo; Park, Bong Kyun

2012-05-01

Since the 2009 pandemic human H1N1 influenza A virus emerged in April 2009, novel reassortant strains have been identified throughout the world. This paper describes the detection and isolation of reassortant strains associated with human pandemic influenza H1N1 and swine influenza H1N2 (SIV) viruses in swine populations in South Korea. Two influenza H1N2 reassortants were detected, and subtyped by PCR. The strains were isolated using Madin- Darby canine kidney (MDCK) cells, and genetically characterized by phylogenetic analysis for genetic diversity. They consisted of human, avian, and swine virus genes that were originated from the 2009 pandemic H1N1 virus and a neuraminidase (NA) gene from H1N2 SIV previously isolated in North America. This identification of reassortment events in swine farms raises concern that reassortant strains may continuously circulate within swine populations, calling for the further study and surveillance of pandemic H1N1 among swine.

Extracorporeal Membrane Oxygenation and Modern Detoxification Techniques in a Puerpera with Viral and Bacterial Pneumonia Caused by Flu A(H1N1 Virus

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R. A. Kornelyuk

2017-01-01

Full Text Available Outbreaks of viral infections have become a global healthcare challenge over the last decade. The 2009—2010 flu A (H1N1 outbreak resulted in global pandemia, associated with high morbidity and mortality reaching 31%. Another flu A (H1N1 outbreak occurred in 2015—2016. There is a strong probability that it may be repeated in the future. This infection is associated with its high incidence among pregnant women. There are some published reports describing the efficacy and safety of veno%venous extracorporeal membrane oxygenation (ECMO in patients with severe acute respiratory distress syndrome that is refractory to standard therapeutic options. The article presents a clinical case of a successful use of extracorporeal membrane oxygenation and intermittent renal replacement therapy in a puerpera with acute respiratory distress syndrome caused by flu A (H1N1-related severe viral and bacterial pneumonia. The positive effects of the combination of veno%venous extracorporeal membrane oxygenation and modern detoxification techniques have been demonstrated. Revealed organizational problemswere related to selection criteria for prescription of extracorporeal gas exchange, as well as to carrying out the procedure in an institution in the deficiency of the experienced staff and corresponding equipment.

Genetic characterization of H1N2 influenza a virus isolated from sick pigs in Southern China in 2010.

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Kong, Wei Li; Huang, Liang Zong; Qi, Hai Tao; Cao, Nan; Zhang, Liang Quan; Wang, Heng; Guan, Shang Song; Qi, Wen Bao; Jiao, Pei Rong; Liao, Ming; Zhang, Gui Hong

2011-10-13

In China H3N2 and H1N1 swine influenza viruses have been circulating for many years. In January 2010, before swine were infected with foot and mouth disease in Guangdong, some pigs have shown flu-like symptoms: cough, sneeze, runny nose and fever. We collected the nasopharyngeal swab of all sick pigs as much as possible. One subtype H1N2 influenza viruses were isolated from the pig population. The complete genome of one isolate, designated A/swine/Guangdong/1/2010(H1N2), was sequenced and compared with sequences available in GenBank. The nucleotide sequences of all eight viral RNA segments were determined, and then phylogenetic analysis was performed using the neighbor-joining method. HA, NP, M and NS were shown to be closely to swine origin. PB2 and PA were close to avian origin, but NA and PB1were close to human origin. It is a result of a multiple reassortment event. In conclusion, our finding provides further evidence about the interspecies transmission of avian influenza viruses to pigs and emphasizes the importance of reinforcing swine influenza virus (SIV) surveillance, especially before the emergence of highly pathogenic FMDs in pigs in Guangdong.

Genetic characterization of H1N2 influenza a virus isolated from sick pigs in Southern China in 2010

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Kong Wei

2011-10-01

Full Text Available Abstract In China H3N2 and H1N1 swine influenza viruses have been circulating for many years. In January 2010, before swine were infected with foot and mouth disease in Guangdong, some pigs have shown flu-like symptoms: cough, sneeze, runny nose and fever. We collected the nasopharyngeal swab of all sick pigs as much as possible. One subtype H1N2 influenza viruses were isolated from the pig population. The complete genome of one isolate, designated A/swine/Guangdong/1/2010(H1N2, was sequenced and compared with sequences available in GenBank. The nucleotide sequences of all eight viral RNA segments were determined, and then phylogenetic analysis was performed using the neighbor-joining method. HA, NP, M and NS were shown to be closely to swine origin. PB2 and PA were close to avian origin, but NA and PB1were close to human origin. It is a result of a multiple reassortment event. In conclusion, our finding provides further evidence about the interspecies transmission of avian influenza viruses to pigs and emphasizes the importance of reinforcing swine influenza virus (SIV surveillance, especially before the emergence of highly pathogenic FMDs in pigs in Guangdong.

Affective language during the H1N1 influenza health crisis

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Morant Marco, Ricard

2010-12-01

Full Text Available In this article we analyze the effects that, as seen through the written press, the arrival of H1N1 had on certain affective behaviors in society. After the spread of H1N1, health authorities recommended maintaining physical distance in social settings and, among other measures, advised against kissing. At first, this show of affection became a victim of the pandemic, especially in certain activities and rituals. However, once the media impact of swine flu had subsided, kissing recovered its habitual place and frequency, demonstrating that customs which are socially and culturally entrenched are resistant to change.

El presente artículo analiza los efectos que según la prensa escrita tuvo la llegada de la gripe A en ciertos comportamientos afectivos de la población. Las autoridades sanitarias, tras la expansión del virus H1N1, recomendaron aumentar la distancia social y aconsejaron, entre otras medidas, evitar los besos. Esta manifestación afectiva, en un primer momento, notó los efectos de la pandemia, sobre todo en ciertas actividades y rituales. Sin embargo, una vez pasado el impacto mediático de la gripe A, recuperó su uso y frecuencia habitual, demostrando que las costumbres fuertemente enraizadas se resisten a cambiar.

Evaluation of clinical features scoring system as screening tool for influenza A (H1N1 in epidemic situations

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P Ranjan

2012-01-01

Full Text Available Background: Influenza A (H1N1 hit the headlines in recent times and created mass hysteria and general panic. The high cost and non-availability of diagnostic laboratory tests for swine flu, especially in the developing countries underlines the need of having a cheaper, easily available, yet reasonably accurate screening test. Aims: This study was carried out to develop a clinical feature-based scoring system (CFSS for influenza A (H1N1 and to evaluate its suitability as a screening tool when large numbers of influenza-like illness cases are suspect. Settings and Design: Clinical-record based study, carried out retrospectively in post-pandemic period on subject′s case-sheets who had been quarantined at IG International Airport′s quarantine center at Delhi. Materials and Methods: Clinical scoring of each suspected case was done by studying their case record sheet and compared with the results of RT-PCR. RT-PCR was used to confirm the diagnosis (Gold Standard. Statistical Analysis: We calculated sensitivity, specificity, positive and negative predictive values of the clinical feature-based scoring system (the proposed new screening tool at different cut-off values. The most discriminant cut-off value was determined by plotting the ROC curve. Results: Of the 638 suspected cases, 127 (20% were confirmed to have H1N1 by RT-PCR examination. On the basis of ROC, the most discriminant clinical feature score for diagnosing Influenza A was found to be 7, which yielded sensitivity, specificity, positive, and negative predictive values of 86%, 88%, 64%, and 96%, respectively. Conclusion: The clinical features scoring system (CFSS can be used as a valid and cost-effective tool for screening swine flu (influenza A (H1N1 cases from large number of influenza-like illness suspects.

Predicting H1N1 vaccine uptake and H1N1-related health beliefs: the role of individual difference in consideration of future consequences.

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Nan, Xiaoli; Kim, Jarim

2014-01-01

This research examines the influence of individual difference in consideration of future consequences on H1N1 vaccine uptake and H1N1-related health beliefs (i.e., perceived susceptibility to and severity of the H1N1 flu, perceived efficacy and safety of the H1N1 vaccine, and perceived self-efficacy in obtaining the H1N1 vaccine). A survey of 411 college students showed that consideration of future consequences had no direct effect on vaccine uptake, but higher consideration of future consequences was associated with greater perceived severity of the flu, higher perceived effectiveness of the vaccine, and greater perceived self-efficacy. Additional analysis suggested that consideration of future consequences had a significant indirect effect on vaccine uptake through perceived vaccine efficacy. Results of the study also revealed gender and racial differences in some of the H1N1-related health beliefs. Implications of the findings for vaccine risk communication are discussed.

[Influenza A/H5N1 virus outbreaks and prepardness to avert flu pandemic].

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Haque, A; Lucas, B; Hober, D

2007-01-01

This review emphasizes the need to improve the knowledge of the biology of H5N1 virus, a candidate for causing the next influenza pandemic. In-depth knowledge of mode of infection, mechanisms of pathogenesis and immune response will help in devising an efficient and practical control strategy against this flu virus. We have discussed limitations of currently available vaccines and proposed novel approaches for making better vaccines against H5N1 influenza virus. They include cell-culture system, reverse genetics, adjuvant development. Our review has also underscored the concept of therapeutic vaccine (anti-disease vaccine), which is aimed at diminishing 'cytokine storm' seen in acute respiratory distress syndrome and/or hemophagocytosis.

Characterization of an artificial swine-origin influenza virus with the same gene combination as H1N1/2009 virus: a genesis clue of pandemic strain.

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Zhao, Xueli; Sun, Yipeng; Pu, Juan; Fan, Lihong; Shi, Weimin; Hu, Yanxin; Yang, Jun; Xu, Qi; Wang, Jingjing; Hou, Dongjun; Ma, Guangpeng; Liu, Jinhua

2011-01-01

Pandemic H1N1/2009 influenza virus, derived from a reassortment of avian, human, and swine influenza viruses, possesses a unique gene segment combination that had not been detected previously in animal and human populations. Whether such a gene combination could result in the pathogenicity and transmission as H1N1/2009 virus remains unclear. In the present study, we used reverse genetics to construct a reassortant virus (rH1N1) with the same gene combination as H1N1/2009 virus (NA and M genes from a Eurasian avian-like H1N1 swine virus and another six genes from a North American triple-reassortant H1N2 swine virus). Characterization of rH1N1 in mice showed that this virus had higher replicability and pathogenicity than those of the seasonal human H1N1 and Eurasian avian-like swine H1N1 viruses, but was similar to the H1N1/2009 and triple-reassortant H1N2 viruses. Experiments performed on guinea pigs showed that rH1N1 was not transmissible, whereas pandemic H1N1/2009 displayed efficient transmissibility. To further determine which gene segment played a key role in transmissibility, we constructed a series of reassortants derived from rH1N1 and H1N1/2009 viruses. Direct contact transmission studies demonstrated that the HA and NS genes contributed to the transmission of H1N1/2009 virus. Second, the HA gene of H1N1/2009 virus, when combined with the H1N1/2009 NA gene, conferred efficient contact transmission among guinea pigs. The present results reveal that not only gene segment reassortment but also amino acid mutation were needed for the generation of the pandemic influenza virus.

Characterization of an artificial swine-origin influenza virus with the same gene combination as H1N1/2009 virus: a genesis clue of pandemic strain.

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Xueli Zhao

Full Text Available Pandemic H1N1/2009 influenza virus, derived from a reassortment of avian, human, and swine influenza viruses, possesses a unique gene segment combination that had not been detected previously in animal and human populations. Whether such a gene combination could result in the pathogenicity and transmission as H1N1/2009 virus remains unclear. In the present study, we used reverse genetics to construct a reassortant virus (rH1N1 with the same gene combination as H1N1/2009 virus (NA and M genes from a Eurasian avian-like H1N1 swine virus and another six genes from a North American triple-reassortant H1N2 swine virus. Characterization of rH1N1 in mice showed that this virus had higher replicability and pathogenicity than those of the seasonal human H1N1 and Eurasian avian-like swine H1N1 viruses, but was similar to the H1N1/2009 and triple-reassortant H1N2 viruses. Experiments performed on guinea pigs showed that rH1N1 was not transmissible, whereas pandemic H1N1/2009 displayed efficient transmissibility. To further determine which gene segment played a key role in transmissibility, we constructed a series of reassortants derived from rH1N1 and H1N1/2009 viruses. Direct contact transmission studies demonstrated that the HA and NS genes contributed to the transmission of H1N1/2009 virus. Second, the HA gene of H1N1/2009 virus, when combined with the H1N1/2009 NA gene, conferred efficient contact transmission among guinea pigs. The present results reveal that not only gene segment reassortment but also amino acid mutation were needed for the generation of the pandemic influenza virus.

Imaging Findings in Patients With H1N1 Influenza A Infection

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Bakhshayeshkaram, Mehrdad; Saidi, Bahareh; Tabarsi, Payam; Zahirifard, Soheila; Ghofrani, Mishka

2011-01-01

Swine influenza (H1N1) is a very contagious respiratory infection and World Health Organization (WHO) has raised the alert level to phase 6 (pandemic). The study of clinical and laboratory manifestations as well as radiologic imaging findings helps in its early diagnosis. The aim of this study was to evaluate the imaging findings of patients with documented H1N1 infection referred to our center. Thirty-one patients (16 men) with documented H1N1 infection were included in our study. The initial radiography obtained from the patients was reviewed regarding pattern (consolidation, ground glass, nodules and reticulation), distribution (focal, multifocal, and diffuse) and the lung zones involved. Computed tomography (CT) scans were also reviewed for the same abnormalities. The patient files were studied for their possible underlying diseases. The mean age was 37.97 ± 13.9 years. Seventeen (54.8%) patients had co-existing condition (eight respiratory, five cardiovascular, two immunodeficiency, two cancer, four others). Twelve (38.7%) patients required intensive care unit (ICU) admission. Five (16.1%) patients died. (25.8%) had normal initial radiographs. The most common abnormality was consolidation (12/31; 38.7%) in the peripheral region (11/31; 35.5%) followed by peribronchovascular areas (10/31; 32.3%) which was most commonly observed in the lower zone. The patients admitted to the ICU were more likely to have two or more lung zones involved (P = 0.005). In patients with the novel swine flu infection, the most common radiographic abnormality observed was consolidation in the lower lung zones. Patients admitted to ICU were more likely to have two or more lung zones involved

Complete genome sequence of a novel influenza A H1N2 virus circulating in swine from Central Bajio region, Mexico.

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Sánchez-Betancourt, J I; Cervantes-Torres, J B; Saavedra-Montañez, M; Segura-Velázquez, R A

2017-12-01

The aim of this study was to perform the complete genome sequence of a swine influenza A H1N2 virus strain isolated from a pig in Guanajuato, México (A/swine/Mexico/GtoDMZC01/2014) and to report its seroprevalence in 86 counties at the Central Bajio zone. To understand the evolutionary dynamics of the isolate, we undertook a phylogenetic analysis of the eight gene segments. These data revealed that the isolated virus is a reassortant H1N2 subtype, as its genes are derived from human (HA, NP, PA) and swine (M, NA, PB1, PB2 and NS) influenza viruses. Pig serum samples were analysed by the hemagglutination inhibition test, using wild H1N2 and H3N2 strains (A/swine/México/Mex51/2010 [H3N2]) as antigen sources. Positive samples to the H1N2 subtype were processed using the field-isolated H1N1 subtype (A/swine/México/Ver37/2010 [H1N1]). Seroprevalence to the H1N2 subtype was 26.74% in the sampled counties, being Jalisco the state with highest seroprevalence to this subtype (35.30%). The results herein reported demonstrate that this new, previously unregistered influenza virus subtype in México that shows internal genes from other swine viral subtypes isolated in the past 5 years, along with human virus-originated genes, is widely distributed in this area of the country. © 2017 Blackwell Verlag GmbH.

Comparative pathogenesis of an avian H5N2 and a swine H1N1 influenza virus in pigs.

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Annebel De Vleeschauwer

2009-08-01

Full Text Available Pigs are considered intermediate hosts for the transmission of avian influenza viruses (AIVs to humans but the basic organ pathogenesis of AIVs in pigs has been barely studied. We have used 42 four-week-old influenza naive pigs and two different inoculation routes (intranasal and intratracheal to compare the pathogenesis of a low pathogenic (LP H5N2 AIV with that of an H1N1 swine influenza virus. The respiratory tract and selected extra-respiratory tissues were examined for virus replication by titration, immunofluorescence and RT-PCR throughout the course of infection. Both viruses caused a productive infection of the entire respiratory tract and epithelial cells in the lungs were the major target. Compared to the swine virus, the AIV produced lower virus titers and fewer antigen positive cells at all levels of the respiratory tract. The respiratory part of the nasal mucosa in particular showed only rare AIV positive cells and this was associated with reduced nasal shedding of the avian compared to the swine virus. The titers and distribution of the AIV varied extremely between individual pigs and were strongly affected by the route of inoculation. Gross lung lesions and clinical signs were milder with the avian than with the swine virus, corresponding with lower viral loads in the lungs. The brainstem was the single extra-respiratory tissue found positive for virus and viral RNA with both viruses. Our data do not reject the theory of the pig as an intermediate host for AIVs, but they suggest that AIVs need to undergo genetic changes to establish full replication potential in pigs. From a biomedical perspective, experimental LP H5 AIV infection of pigs may be useful to examine heterologous protection provided by H5 vaccines or other immunization strategies, as well as for further studies on the molecular pathogenesis and neurotropism of AIVs in mammals.

Computer-aided assessment of pulmonary disease in novel swine-origin H1N1 influenza on CT

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Yao, Jianhua; Dwyer, Andrew J.; Summers, Ronald M.; Mollura, Daniel J.

2011-03-01

The 2009 pandemic is a global outbreak of novel H1N1 influenza. Radiologic images can be used to assess the presence and severity of pulmonary infection. We develop a computer-aided assessment system to analyze the CT images from Swine-Origin Influenza A virus (S-OIV) novel H1N1 cases. The technique is based on the analysis of lung texture patterns and classification using a support vector machine (SVM). Pixel-wise tissue classification is computed from the SVM value. The method was validated on four H1N1 cases and ten normal cases. We demonstrated that the technique can detect regions of pulmonary abnormality in novel H1N1 patients and differentiate these regions from visually normal lung (area under the ROC curve is 0.993). This technique can also be applied to differentiate regions infected by different pulmonary diseases.

Seroprevalence of H1N1, H3N2 and H1N2 influenza viruses in pigs in seven European countries in 2002-2003.

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Van Reeth, Kristien; Brown, Ian H; Dürrwald, Ralf; Foni, Emanuela; Labarque, Geoffrey; Lenihan, Patrick; Maldonado, Jaime; Markowska-Daniel, Iwona; Pensaert, Maurice; Pospisil, Zdenek; Koch, Guus

2008-05-01

Avian-like H1N1 and human-like H3N2 swine influenza viruses (SIV) have been considered widespread among pigs in Western Europe since the 1980s, and a novel H1N2 reassortant with a human-like H1 emerged in the mid 1990s. This study, which was part of the EC-funded 'European Surveillance Network for Influenza in Pigs 1', aimed to determine the seroprevalence of the H1N2 virus in different European regions and to compare the relative prevalences of each SIV between regions. Laboratories from Belgium, the Czech Republic, Germany, Italy, Ireland, Poland and Spain participated in an international serosurvey. A total of 4190 sow sera from 651 farms were collected in 2002-2003 and examined in haemagglutination inhibition tests against H1N1, H3N2 and H1N2. In Belgium, Germany, Italy and Spain seroprevalence rates to each of the three SIV subtypes were high (> or =30% of the sows seropositive) to very high (> or =50%), except for a lower H1N2 seroprevalence rate in Italy (13.8%). Most sows in these countries with high pig populations had antibodies to two or three subtypes. In Ireland, the Czech Republic and Poland, where swine farming is less intensive, H1N1 was the dominant subtype (8.0-11.7% seropositives) and H1N2 and H3N2 antibodies were rare (0-4.2% seropositives). Thus, SIV of H1N1, H3N2 and H1N2 subtype are enzootic in swine producing regions of Western Europe. In Central Europe, SIV activity is low and the circulation of H3N2 and H1N2 remains to be confirmed. The evolution and epidemiology of SIV throughout Europe is being further monitored through a second 'European Surveillance Network for Influenza in Pigs'.

Evidence of reassortment of pandemic H1N1 influenza virus in swine in Argentina: are we facing the expansion of potential epicenters of influenza emergence?

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Pereda, Ariel; Rimondi, Agustina; Cappuccio, Javier; Sanguinetti, Ramon; Angel, Matthew; Ye, Jianqiang; Sutton, Troy; Dibárbora, Marina; Olivera, Valeria; Craig, Maria I.; Quiroga, Maria; Machuca, Mariana; Ferrero, Andrea; Perfumo, Carlos; Perez, Daniel R.

2011-01-01

Please cite this paper as: Pereda et al. (2011) Evidence of reassortment of pandemic H1N1 influenza virus in swine in Argentina: are we facing the expansion of potential epicenters of influenza emergence? Influenza and Other Respiratory Viruses 5(6), 409–412. In this report, we describe the occurrence of two novel swine influenza viruses (SIVs) in pigs in Argentina. These viruses are the result of two independent reassortment events between the H1N1 pandemic influenza virus (H1N1pdm) and human‐like SIVs, showing the constant evolution of influenza viruses at the human–swine interface and the potential health risk of H1N1pdm as it appears to be maintained in the swine population. It must be noted that because of the lack of information regarding the circulation of SIVs in South America, we cannot discard the possibility that ancestors of the H1N1pdm or other SIVs have been present in this part of the world. More importantly, these findings suggest an ever‐expanding geographic range of potential epicenters of influenza emergence with public health risks. PMID:21668680

Swine Influenza Virus PA and Neuraminidase Gene Reassortment into Human H1N1 Influenza Virus Is Associated with an Altered Pathogenic Phenotype Linked to Increased MIP-2 Expression.

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Dlugolenski, Daniel; Jones, Les; Howerth, Elizabeth; Wentworth, David; Tompkins, S Mark; Tripp, Ralph A

2015-05-01

Swine are susceptible to infection by both avian and human influenza viruses, and this feature is thought to contribute to novel reassortant influenza viruses. In this study, the influenza virus reassortment rate in swine and human cells was determined. Coinfection of swine cells with 2009 pandemic H1N1 virus (huH1N1) and an endemic swine H1N2 (A/swine/Illinois/02860/09) virus (swH1N2) resulted in a 23% reassortment rate that was independent of α2,3- or α2,6-sialic acid distribution on the cells. The reassortants had altered pathogenic phenotypes linked to introduction of the swine virus PA and neuraminidase (NA) into huH1N1. In mice, the huH1N1 PA and NA mediated increased MIP-2 expression early postinfection, resulting in substantial pulmonary neutrophilia with enhanced lung pathology and disease. The findings support the notion that swine are a mixing vessel for influenza virus reassortants independent of sialic acid distribution. These results show the potential for continued reassortment of the 2009 pandemic H1N1 virus with endemic swine viruses and for reassortants to have increased pathogenicity linked to the swine virus NA and PA genes which are associated with increased pulmonary neutrophil trafficking that is related to MIP-2 expression. Influenza A viruses can change rapidly via reassortment to create a novel virus, and reassortment can result in possible pandemics. Reassortments among subtypes from avian and human viruses led to the 1957 (H2N2 subtype) and 1968 (H3N2 subtype) human influenza pandemics. Recent analyses of circulating isolates have shown that multiple genes can be recombined from human, avian, and swine influenza viruses, leading to triple reassortants. Understanding the factors that can affect influenza A virus reassortment is needed for the establishment of disease intervention strategies that may reduce or preclude pandemics. The findings from this study show that swine cells provide a mixing vessel for influenza virus reassortment

Performance of the Directigen EZ Flu A+B rapid influenza diagnostic test to detect pandemic influenza A/H1N1 2009.

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Boyanton, Bobby L; Almradi, Amro; Mehta, Tejal; Robinson-Dunn, Barbara

2014-04-01

The Directigen EZ Flu A+B rapid influenza diagnostic test, as compared to real-time reverse transcriptase polymerase chain reaction, demonstrated suboptimal performance to detect pandemic influenza A/H1N1 2009. Age- and viral load-stratified test sensitivity ranged from 33.3 to 84.6% and 0 to 100%, respectively. © 2013.

Potential Intensive Care unit Ventilator Demand/Capacity Mismatch due to Novel Swine-Origin H1N1 in Canada

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Paul Smetanin

2009-01-01

Full Text Available PURPOSE: To investigate the ability of Canadian intensive care units (ICUs and ventilators to handle widespread re-emergence of the swine-origin H1N1 virus in the context of an aggressive strategy of vaccination.

Population dynamics of swine influenza virus in finishing pigs

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Loeffen, W.L.A.

2008-01-01

Influenza virus infections in swine were first noticed in the US in 1918, during the human pandemic of the Spanish flu. In Europe, seroprevalences for the three most common swine influenza strains at the moment, H1N1, H3N2 and H1N2, range from 20-80% in finishing pigs at the end of the finishing

Genetic divergence of influenza A NS1 gene in pandemic 2009 H1N1 isolates with respect to H1N1 and H3N2 isolates from previous seasonal epidemics

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Campanini Giulia

2010-09-01

Full Text Available Abstract Background The Influenza A pandemic sustained by a new H1N1 variant (H1N1v started in Mexico and the USA at the end of April 2009 spreading worldwide in a few weeks. In this study we investigate the variability of the NS1 gene of the pandemic H1N1v strain with respect to previous seasonal strains circulating in humans and the potential selection of virus variants through isolation in cell culture. Methods During the period April 27th 2009-Jan 15th 2010, 1633 potential 2009 H1N1v cases have been screened at our center using the CDC detection and typing realtime RT-PCR assays. Virus isolation on MDCK cells was systematically performed in 1/10 positive cases. A subset of 51 H1N1v strains isolated in the period May-September 2009 was selected for NS1 gene sequencing. In addition, 15 H1N1 and 47 H3N2 virus isolates from three previous seasonal epidemics (2006-2009 were analyzed in parallel. Results A low variability in the NS1 amino acid (aa sequence among H1N1v isolates was shown (aa identity 99.5%. A slightly higher NS1 variability was observed among H1N1 and H3N2 strains from previous epidemics (aa identity 98.6% and 98.9%, respectively. The H1N1v strains were closely related (aa identity 92.1% to swine reference strain (A/swine/Oklahoma/042169/2008. In contrast, substantial divergence (aa identity 83.4% with respect to human reference strain A/Brevig Mission/1/1918 and previous epidemic strains H1N1 and H3N2 (aa identity 78.9% and 77.6%, respectively was shown. Specific sequence signatures of uncertain significance in the new virus variant were a C-terminus deletion and a T215P substitution. Conclusions The H1N1v NS1 gene was more conserved than that of previous epidemic strains. In addition, a closer genetic identity of H1N1v with the swine than the human reference strains was shown. Hot-spots were shown in the H1N1v NS1 aa sequence whose biologic relevance remains to be investigated.

Are there any differences in clinical and laboratory findings on admission between H1N1 positive and negative patients with flu-like symptoms?

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Zarogoulidis Kostas

2011-01-01

Full Text Available Abstract Background The World Health Organization alert for the H1N1 influenza pandemic led to the implementation of certain measures regarding admission of patients with flu-like symptoms. All these instructions were adopted by the Greek National Health System. The aim of this study was to retrospectively examine the characteristics of all subjects admitted to the Unit of Infectious Diseases with symptoms indicating H1N1 infection, and to identify any differences between H1N1 positive or negative patients. Patients from the ED (emergency department with flu-like symptoms (sore throat, cough, rhinorhea, or nasal congestion and fever >37.5°C were admitted in the Unit of Infectious diseases and gave pharyngeal or nasopharyngeal swabs. Swabs were tested with real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR. Findings Patients were divided into two groups. Group A comprised 33 H1N1 positive patients and Group B (control group comprised of 27 H1N1 negative patients. The two groups did not differ in terms of patient age, co-morbidities, length of hospitalization, temperature elevation, hypoxemia, as well as renal and liver function. There were also no significant differences in severity on admission. C-reactive protein (CRP (mean 12.8 vs. 5.74 and white blood count (WBC (mean 10.528 vs. 7.114 were significantly higher in group B than in group A upon admission. Obesity was noted in 8 patients of Group A (mean 31.67 and 14 patients of Group B (mean 37.78. Body mass index (BMI was lower in H1N1 positive than in H1N1 negative patients (mean 31.67 vs. 37.78, respectively; p = 0.009. Conclusions The majority of patients in both groups were young male adults. CRP, WBC and BMI were higher among H1N1 negative patients. Finally, clinical course of patients in both groups was mild and uneventful.

Seroprevalence of H1N1, H3N2 and H1N2 influenza viruses in pigs in seven European countries in 2002-2003

NARCIS (Netherlands)

Reeth, K.; Brown, I.H.; Durrwald, R.; Foni, E.; Labarque, G.; Lenihan, P.; Maldonado, J.; Markowska-Daniel, I.; Pensaert, M.; Pospisil, Z.; Koch, G.

2008-01-01

Objectives Avian-like H1N1 and human-like H3N2 swine influenza viruses (SIV) have been considered widespread among pigs in Western Europe since the 1980s, and a novel H1N2 reassortant with a human-like H1 emerged in the mid 1990s. This study, which was part of the EC-funded 'European Surveillance

Assessing Google flu trends performance in the United States during the 2009 influenza virus A (H1N1 pandemic.

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Samantha Cook

Full Text Available BACKGROUND: Google Flu Trends (GFT uses anonymized, aggregated internet search activity to provide near-real time estimates of influenza activity. GFT estimates have shown a strong correlation with official influenza surveillance data. The 2009 influenza virus A (H1N1 pandemic [pH1N1] provided the first opportunity to evaluate GFT during a non-seasonal influenza outbreak. In September 2009, an updated United States GFT model was developed using data from the beginning of pH1N1. METHODOLOGY/PRINCIPAL FINDINGS: We evaluated the accuracy of each U.S. GFT model by comparing weekly estimates of ILI (influenza-like illness activity with the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet. For each GFT model we calculated the correlation and RMSE (root mean square error between model estimates and ILINet for four time periods: pre-H1N1, Summer H1N1, Winter H1N1, and H1N1 overall (Mar 2009-Dec 2009. We also compared the number of queries, query volume, and types of queries (e.g., influenza symptoms, influenza complications in each model. Both models' estimates were highly correlated with ILINet pre-H1N1 and over the entire surveillance period, although the original model underestimated the magnitude of ILI activity during pH1N1. The updated model was more correlated with ILINet than the original model during Summer H1N1 (r = 0.95 and 0.29, respectively. The updated model included more search query terms than the original model, with more queries directly related to influenza infection, whereas the original model contained more queries related to influenza complications. CONCLUSIONS: Internet search behavior changed during pH1N1, particularly in the categories "influenza complications" and "term for influenza." The complications associated with pH1N1, the fact that pH1N1 began in the summer rather than winter, and changes in health-seeking behavior each may have played a part. Both GFT models performed well prior to and during pH1

Assessing Google Flu Trends Performance in the United States during the 2009 Influenza Virus A (H1N1) Pandemic

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Cook, Samantha; Conrad, Corrie; Fowlkes, Ashley L.; Mohebbi, Matthew H.

2011-01-01

Background Google Flu Trends (GFT) uses anonymized, aggregated internet search activity to provide near-real time estimates of influenza activity. GFT estimates have shown a strong correlation with official influenza surveillance data. The 2009 influenza virus A (H1N1) pandemic [pH1N1] provided the first opportunity to evaluate GFT during a non-seasonal influenza outbreak. In September 2009, an updated United States GFT model was developed using data from the beginning of pH1N1. Methodology/Principal Findings We evaluated the accuracy of each U.S. GFT model by comparing weekly estimates of ILI (influenza-like illness) activity with the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet). For each GFT model we calculated the correlation and RMSE (root mean square error) between model estimates and ILINet for four time periods: pre-H1N1, Summer H1N1, Winter H1N1, and H1N1 overall (Mar 2009–Dec 2009). We also compared the number of queries, query volume, and types of queries (e.g., influenza symptoms, influenza complications) in each model. Both models' estimates were highly correlated with ILINet pre-H1N1 and over the entire surveillance period, although the original model underestimated the magnitude of ILI activity during pH1N1. The updated model was more correlated with ILINet than the original model during Summer H1N1 (r = 0.95 and 0.29, respectively). The updated model included more search query terms than the original model, with more queries directly related to influenza infection, whereas the original model contained more queries related to influenza complications. Conclusions Internet search behavior changed during pH1N1, particularly in the categories “influenza complications” and “term for influenza.” The complications associated with pH1N1, the fact that pH1N1 began in the summer rather than winter, and changes in health-seeking behavior each may have played a part. Both GFT models performed well prior to and during pH1N1

Evaluation of the zoonotic potential of a novel reassortant H1N2 swine influenza virus with gene constellation derived from multiple viral sources.

Science.gov (United States)

Lee, Jee Hoon; Pascua, Philippe Noriel Q; Decano, Arun G; Kim, Se Mi; Park, Su-Jin; Kwon, Hyeok-Il; Kim, Eun-Ha; Kim, Young-Il; Kim, HyongKyu; Kim, Seok-Yong; Song, Min-Suk; Jang, Hyung-Kwan; Park, Bong Kyun; Choi, Young Ki

2015-08-01

In 2011-2012, contemporary North American-like H3N2 swine influenza viruses (SIVs) possessing the 2009 pandemic H1N1 matrix gene (H3N2pM-like virus) were detected in domestic pigs of South Korea where H1N2 SIV strains are endemic. More recently, we isolated novel reassortant H1N2 SIVs bearing the Eurasian avian-like swine H1-like hemagglutinin and Korean swine H1N2-like neuraminidase in the internal gene backbone of the H3N2pM-like virus. In the present study, we clearly provide evidence on the genetic origins of the novel H1N2 SIVs virus through genetic and phylogenetic analyses. In vitro studies demonstrated that, in comparison with a pre-existing 2012 Korean H1N2 SIV [A/swine/Korea/CY03-11/2012 (CY03-11/2012)], the 2013 novel reassortant H1N2 isolate [A/swine/Korea/CY0423/2013 (CY0423-12/2013)] replicated more efficiently in differentiated primary human bronchial epithelial cells. The CY0423-12/2013 virus induced higher viral titers than the CY03-11/2012 virus in the lungs and nasal turbinates of infected mice and nasal wash samples of ferrets. Moreover, the 2013 H1N2 reassortant, but not the intact 2012 H1N2 virus, was transmissible to naïve contact ferrets via respiratory-droplets. Noting that the viral precursors have the ability to infect humans, our findings highlight the potential threat of a novel reassortant H1N2 SIV to public health and underscore the need to further strengthen influenza surveillance strategies worldwide, including swine populations. Copyright © 2015 Elsevier B.V. All rights reserved.

Two different genotypes of H1N2 swine influenza virus isolated in northern China and their pathogenicity in animals.

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Yang, Huanliang; Chen, Yan; Qiao, Chuanling; Xu, Chuantian; Yan, Minghua; Xin, Xiaoguang; Bu, Zhigao; Chen, Hualan

2015-02-25

During 2006 and 2007, two swine-origin triple-reassortant influenza A (H1N2) viruses were isolated from pigs in northern China, and the antigenic characteristics of the hemagglutinin protein of the viruses were examined. Genotyping and phylogenetic analyses demonstrated different emergence patterns for the two H1N2 viruses, Sw/Hebei/10/06 and Sw/Tianjin/1/07. Sequences for the other genes encoding the internal proteins were compared with the existing data to determine their origins and establish the likely mechanisms of genetic reassortment. Sw/Hebei/10/06 is an Sw/Indiana/9K035/99-like virus, whereas Sw/Tianjin/1/07 represents a new H1N2 genotype with surface genes of classic swine and human origin and internal genes originating from the Eurasian avian-like swine H1N1 virus. Six-week-old female BALB/c mice infected with the Sw/HeB/10/06 and Sw/TJ/1/07 viruses showed an average weight loss of 12.8% and 8.1%, respectively. Healthy six-week-old pigs were inoculated intranasally with either the Sw/HeB/10/06 or Sw/TJ/1/07 virus. No considerable changes in the clinical presentation were observed post-inoculation in any of the virus-inoculated groups, and the viruses effectively replicated in the nasal cavity and lung tissue. Based on the results, it is possible that the new genotype of the swine H1N2 virus that emerged in China may become widespread in the swine population and pose a potential threat to public health. Copyright © 2014 Elsevier B.V. All rights reserved.

Swine Flu, in the Spanish Press/La ‘gripe A’, en la prensa española

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Dra. Idoia Camacho Markina

2009-01-01

Full Text Available Abstract: Mass media are faced with an exceptional challenge when they cover an epidemic, since the role of the media is to offer the most complete and accurate information in order to avoid spreading panic. However, many media outlets have been guided by financial reasons rather than public service criteria when they have covered the latest epidemic outbreak, which has resulted in a sensationalist coverage. The goal of this paper is to analyze the news coverage given by Spanish dailies to the outbreak and spread of the Novel H1N1 Virus, commonly known as the Swine Flu. This research points to the role played by print media in the coverage of this particular issue after a content analysis of the news articles published by the main five Spanish dailies during the first week after the Swine Flu outbreak.Resumen: Informar sobre epidemias constituye una situación excepcional para los medios de comunicación, cuya función debe ser ofrecer al público la información más completa posible para evitar que se extienda el pánico. Sin embargo, en las últimas epidemias muchos medios se han guiado más por criterios económicos, buscando el sensacionalismo, que por criterios de servicio público. El presente trabajo tiene como objetivo estudiar el tratamiento informativo que la prensa escrita diaria española ha hecho del brote de epidemia del virus de influenza A (H1/N1. El análisis de contenido de las noticias publicadas por los cinco diarios españoles de mayor difusión en la primera semana desde que se conoció la epidemia nos indica qué papel ha adoptado la prensa en esta ocasión.

Novel triple reassortant H1N2 influenza viruses bearing six internal genes of the pandemic 2009/H1N1 influenza virus were detected in pigs in China.

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Qiao, Chuanling; Liu, Liping; Yang, Huanliang; Chen, Yan; Xu, Huiyang; Chen, Hualan

2014-12-01

The pandemic A/H1N1 influenza viruses emerged in both Mexico and the United States in March 2009, and were transmitted efficiently in the human population. Transmissions of the pandemic 2009/H1N1 virus from humans to poultry and other species of mammals were reported from several continents during the course of the 2009 H1N1 pandemic. Reassortant H1N1, H1N2, and H3N2 viruses containing genes of the pandemic 2009/H1N1 viruses appeared in pigs in some countries. In winter of 2012, a total of 2600 nasal swabs were collected from healthy pigs in slaughterhouses located throughout 10 provinces in China. The isolated viruses were subjected to genetic and antigenic analysis. Two novel triple-reassortant H1N2 influenza viruses were isolated from swine in China in 2012, with the HA gene derived from Eurasian avian-like swine H1N1, the NA gene from North American swine H1N2, and the six internal genes from the pandemic 2009/H1N1 viruses. The two viruses had similar antigenic features and some significant changes in antigenic characteristics emerged when compared to the previously identified isolates. We inferred that the novel reassortant viruses in China may have arisen from the accumulation of the three types of influenza viruses, which further indicates that swine herds serve as "mixing vessels" for influenza viruses. Influenza virus reassortment is an ongoing process, and our findings highlight the urgent need for continued influenza surveillance among swine herds. Copyright © 2014 Elsevier B.V. All rights reserved.

Spread of H1N1 within Households

Centers for Disease Control (CDC) Podcasts

This podcast describes an investigation into how H1N1 was spreading within households during the initial days of the pandemic in Texas. CDC's Dr. Oliver Morgan discusses what investigators learned about the role that children played in introducing the virus into households and spreading flu.

A monoclonal antibody-based ELISA for differential diagnosis of 2009 pandemic H1N1

Science.gov (United States)

The swine-origin 2009 pandemic H1N1 virus (pdmH1N1) is genetically related to North American swine H1 influenza viruses and unrelated to human seasonal H1 viruses. Currently, specific diagnosis of pdmH1N1 relies on RT-PCR. In order to develop an assay that does not rely in amplification of the viral...

Virulence and transmissibility of H1N2 influenza virus in ferrets imply the continuing threat of triple-reassortant swine viruses.

Science.gov (United States)

Pascua, Philippe Noriel Q; Song, Min-Suk; Lee, Jun Han; Baek, Yun Hee; Kwon, Hyeok-il; Park, Su-Jin; Choi, Eun Hye; Lim, Gyo-Jin; Lee, Ok-Jun; Kim, Si-Wook; Kim, Chul-Joong; Sung, Moon Hee; Kim, Myung Hee; Yoon, Sun-Woo; Govorkova, Elena A; Webby, Richard J; Webster, Robert G; Choi, Young-Ki

2012-09-25

Efficient worldwide swine surveillance for influenza A viruses is urgently needed; the emergence of a novel reassortant pandemic H1N1 (pH1N1) virus in 2009 demonstrated that swine can be the direct source of pandemic influenza and that the pandemic potential of viruses prevalent in swine populations must be monitored. We used the ferret model to assess the pathogenicity and transmissibility of predominant Korean triple-reassortant swine (TRSw) H1N2 and H3N2 influenza viruses genetically related to North American strains. Although most of the TRSw viruses were moderately pathogenic, one [A/Swine/Korea/1204/2009; Sw/1204 (H1N2)] was virulent in ferrets, causing death within 10 d of inoculation, and was efficiently transmitted to naive contact ferrets via respiratory droplets. Although molecular analysis did not reveal known virulence markers, the Sw/1204 virus acquired mutations in hemagglutinin (HA) (Asp-225-Gly) and neuraminidase (NA) (Ser-315-Asn) proteins during the single ferret passage. The contact-Sw/1204 virus became more virulent in mice, replicated efficiently in vitro, extensively infected human lung tissues ex vivo, and maintained its ability to replicate and transmit in swine. Reverse-genetics studies further indicated that the HA(225G) and NA(315N) substitutions contributed substantially in altering virulence and transmissibility. These findings support the continuing threat of some field TRSw viruses to human and animal health, reviving concerns on the capacity of pigs to create future pandemic viruses. Apart from warranting continued and enhanced global surveillance, this study also provides evidence on the emerging roles of HA(225G) and NA(315N) as potential virulence markers in mammals.

[Phylogenetic analysis of human/swine/avian gene reassortant H1N2 influenza A virus isolated from a pig in China].

Science.gov (United States)

Chen, Yixiang; Meng, Xueqiong; Liu, Qi; Huang, Xia; Huang, Shengbin; Liu, Cuiquan; Shi, Kaichuang; Guo, Jiangang; Chen, Fangfang; Hu, Liping

2008-04-01

Our aim in this study was to determine the genetic characterization and probable origin of the H1N2 swine influenza virus (A/Swine/Guangxi/13/2006) (Sw/GX/13/06) from lung tissue of a pig in Guangxi province, China. Eight genes of Sw/GX/13/06 were cloned and genetically analyzed. The hemagglutinin (HA), nucleoprotein (NP), matrix (M) and non-structural (NS) genes of Sw/GX/13/06 were most closely related to genes from the classical swine H1N1 influenza virus lineage. The neuraminidase (NA) and PB1 genes were most closely related to the corresponding genes from the human influenza H3N2 virus lineage. The remaining two genes PA and PB2 polymerase genes were most closely related to the genes from avian influenza virus lineage. Phylogenetic analyses revealed that Sw/GX/13/06 was a human/swine/avian H1N2 virus, and closely related to H1N2 viruses isolated from pigs in United States (1999-2001) and Korea (2002). To our knowledge, Sw/GX/13/06 was the first triple-reassortant H1N2 influenza A virus isolated from a pig in China. Whether the Sw/GX/13/06 has a potential threat to breeding farm and human health remains to be further investigated.

Anti-viral properties and mode of action of standardized Echinacea purpurea extract against highly pathogenic avian Influenza virus (H5N1, H7N7 and swine-origin H1N1 (S-OIV

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Schoop Roland

2009-11-01

Full Text Available Abstract Background Influenza virus (IV infections are a major threat to human welfare and animal health worldwide. Anti-viral therapy includes vaccines and a few anti-viral drugs. However vaccines are not always available in time, as demonstrated by the emergence of the new 2009 H1N1-type pandemic strain of swine origin (S-OIV in April 2009, and the acquisition of resistance to neuraminidase inhibitors such as Tamiflu® (oseltamivir is a potential problem. Therefore the prospects for the control of IV by existing anti-viral drugs are limited. As an alternative approach to the common anti-virals we studied in more detail a commercial standardized extract of the widely used herb Echinacea purpurea (Echinaforce®, EF in order to elucidate the nature of its anti-IV activity. Results Human H1N1-type IV, highly pathogenic avian IV (HPAIV of the H5- and H7-types, as well as swine origin IV (S-OIV, H1N1, were all inactivated in cell culture assays by the EF preparation at concentrations ranging from the recommended dose for oral consumption to several orders of magnitude lower. Detailed studies with the H5N1 HPAIV strain indicated that direct contact between EF and virus was required, prior to infection, in order to obtain maximum inhibition in virus replication. Hemagglutination assays showed that the extract inhibited the receptor binding activity of the virus, suggesting that the extract interferes with the viral entry into cells. In sequential passage studies under treatment in cell culture with the H5N1 virus no EF-resistant variants emerged, in contrast to Tamiflu®, which produced resistant viruses upon passaging. Furthermore, the Tamiflu®-resistant virus was just as susceptible to EF as the wild type virus. Conclusion As a result of these investigations, we believe that this standard Echinacea preparation, used at the recommended dose for oral consumption, could be a useful, readily available and affordable addition to existing control options

Evidence of cross-reactive immunity to 2009 pandemic influenza A virus in workers seropositive to swine H1N1 influenza viruses circulating in Italy.

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Maria A De Marco

Full Text Available BACKGROUND: Pigs play a key epidemiologic role in the ecology of influenza A viruses (IAVs emerging from animal hosts and transmitted to humans. Between 2008 and 2010, we investigated the health risk of occupational exposure to swine influenza viruses (SIVs in Italy, during the emergence and spread of the 2009 H1N1 pandemic (H1N1pdm virus. METHODOLOGY/PRINCIPAL FINDINGS: Serum samples from 123 swine workers (SWs and 379 control subjects (Cs, not exposed to pig herds, were tested by haemagglutination inhibition (HI assay against selected SIVs belonging to H1N1 (swH1N1, H1N2 (swH1N2 and H3N2 (swH3N2 subtypes circulating in the study area. Potential cross-reactivity between swine and human IAVs was evaluated by testing sera against recent, pandemic and seasonal, human influenza viruses (H1N1 and H3N2 antigenic subtypes. Samples tested against swH1N1 and H1N1pdm viruses were categorized into sera collected before (n. 84 SWs; n. 234 Cs and after (n. 39 SWs; n. 145 Cs the pandemic peak. HI-antibody titers ≥10 were considered positive. In both pre-pandemic and post-pandemic peak subperiods, SWs showed significantly higher swH1N1 seroprevalences when compared with Cs (52.4% vs. 4.7% and 59% vs. 9.7%, respectively. Comparable HI results were obtained against H1N1pdm antigen (58.3% vs. 7.7% and 59% vs. 31.7%, respectively. No differences were found between HI seroreactivity detected in SWs and Cs against swH1N2 (33.3% vs. 40.4% and swH3N2 (51.2 vs. 55.4% viruses. These findings indicate the occurrence of swH1N1 transmission from pigs to Italian SWs. CONCLUSION/SIGNIFICANCE: A significant increase of H1N1pdm seroprevalences occurred in the post-pandemic peak subperiod in the Cs (p<0.001 whereas SWs showed no differences between the two subperiods, suggesting a possible occurrence of cross-protective immunity related to previous swH1N1 infections. These data underline the importance of risk assessment and occupational health surveillance activities aimed

Clinical experience in treatment of five H1N1 flu patients with respiratory failure with high-frequency oscillatory mechanical ventilation

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Zhi-gang ZHANG

2011-08-01

Full Text Available Objective To investigate the application and safety of high-frequency oscillation ventilation(HFOV in the treatment of patients suffering from H1N1 influenza with respiratory failure.Methods Self-control study was conducted.The treatment of five H1N1 influenza patients with respiratory failure was switched to HFOV after failure of conventional mechanical ventilation(CMV.Blood gas [partial pressure of oxygen(PaO2,partial pressure of carbon dioxide(PCO2,pH],respiratory mechanics indices [oxygen concentration(FiO2,mean airway pressure(Paw,static response(Cst,oxygenation index(PaO2/FiO2] before and after treatment were observed.Lung biopsy and clinical treatment data were also analyzed.Results Oxygenation was improved in 3 patients 6 to 8 hours after HFOV treatment,and marked improvement was observed after 24-48h.48-72h later,HFOV was replaced by CMV,and the patients weaned from mechanical ventilation successfully at 144h.In two patients symptoms were exacerbated after HFOV for 8 hours and the treatment was switched to CMV.Among them one died at 75h,and another one was treated with extracorporeal membrane oxygenation(ECMO and died at 145h.Conclusions HFOV can significantly improve the outcome of H1N1 flu patients with respiratory failure.The sequential treatment with HFOV followed by CMV can reduce complications and mortality.

Lymphadenitis as a Rare Side Effect of H1N1 Vaccine in a Child

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Zuhal Gundogdu

2010-01-01

Full Text Available We present a 5-year-old boy who had the complaint of swelling and pain on the right vaccine shot and right axillary areas. The right axillary area was diagnosed as reactive lymphadenitis, which we believe is a rare local side effect of the swine flu vaccine. The key message to take away from this case is that the patient had lymphadenitis as a local side effect of the swine flu vaccine. Lymphadenitis should be reported as a possible local side effect of the swine flu vaccine.

Lymphadenitis as a Rare Side Effect of H1N1 Vaccine in a Child

Science.gov (United States)

Gundogdu, Zuhal; Seyhogullari, Mualla

2010-01-01

We present a 5-year-old boy who had the complaint of swelling and pain on the right vaccine shot and right axillary areas. The right axillary area was diagnosed as reactive lymphadenitis, which we believe is a rare local side effect of the swine flu vaccine. The key message to take away from this case is that the patient had lymphadenitis as a local side effect of the swine flu vaccine. Lymphadenitis should be reported as a possible local side effect of the swine flu vaccine. PMID:21209734

Antigenic and genetic evolution of contemporary swine H1 influenza viruses in the United States.

Science.gov (United States)

Rajao, Daniela S; Anderson, Tavis K; Kitikoon, Pravina; Stratton, Jered; Lewis, Nicola S; Vincent, Amy L

2018-05-01

Several lineages of influenza A viruses (IAV) currently circulate in North American pigs. Genetic diversity is further increased by transmission of IAV between swine and humans and subsequent evolution. Here, we characterized the genetic and antigenic evolution of contemporary swine H1N1 and H1N2 viruses representing clusters H1-α (1A.1), H1-β (1A.2), H1pdm (1A.3.3.2), H1-γ (1A.3.3.3), H1-δ1 (1B.2.2), and H1-δ2 (1B.2.1) currently circulating in pigs in the United States. The δ1-viruses diversified into two new genetic clades, H1-δ1a (1B.2.2.1) and H1-δ1b (1B.2.2.2), which were also antigenically distinct from the earlier H1-δ1-viruses. Further characterization revealed that a few key amino acid changes were associated with antigenic divergence in these groups. The continued genetic and antigenic evolution of contemporary H1 viruses might lead to loss of vaccine cross-protection that could lead to significant economic impact to the swine industry, and represents a challenge to public health initiatives that attempt to minimize swine-to-human IAV transmission. Published by Elsevier Inc.

Deciphering the Swine-Flu Pandemics of 1918 and 2009

Science.gov (United States)

Goldstein, Richard; Dos Reis, Mario; Tamuri, Asif; Hay, Alan

The devastating "Spanish flu" of 1918 killed an estimated 50 million people worldwide, ranking it as the deadliest pandemic in recorded human history. It is generally believed that the virus transferred from birds directly to humans shortly before the start of the pandemic, subsequently jumping from humans to swine. By developing 'non-homogeneous' substitution models that consider that substitution patterns may be different in human, avian, and swine hosts, we can determine the timing of the host shift to mammals. We find it likely that the Spanish flu of 1918, like the current 2009 pandemic, was a 'swine-origin' influenza virus. Now that we are faced with a new pandemic, can we understand how influenza is able to change hosts? Again by modelling the evolutionary process, considering the different selective constraints for viruses in the different hosts, we can identify locations that seem to be under different selective constraints in humans and avian hosts. This allows us to identify changes that may have facilitated the establishment of the 2009 swine-origin flu in humans.

Molecular dynamics simulations suggest that electrostatic funnel directs binding of Tamiflu to influenza N1 neuraminidases.

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Ly Le

2010-09-01

Full Text Available Oseltamivir (Tamiflu is currently the frontline antiviral drug employed to fight the flu virus in infected individuals by inhibiting neuraminidase, a flu protein responsible for the release of newly synthesized virions. However, oseltamivir resistance has become a critical problem due to rapid mutation of the flu virus. Unfortunately, how mutations actually confer drug resistance is not well understood. In this study, we employ molecular dynamics (MD and steered molecular dynamics (SMD simulations, as well as graphics processing unit (GPU-accelerated electrostatic mapping, to uncover the mechanism behind point mutation induced oseltamivir-resistance in both H5N1 "avian" and H1N1pdm "swine" flu N1-subtype neuraminidases. The simulations reveal an electrostatic binding funnel that plays a key role in directing oseltamivir into and out of its binding site on N1 neuraminidase. The binding pathway for oseltamivir suggests how mutations disrupt drug binding and how new drugs may circumvent the resistance mechanisms.

Comparative evaluation of acute respiratory distress syndrome in patients with and without H1N1 infection at a tertiary care referral center

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Tanvir Samra

2011-01-01

Full Text Available H1N1 subtype of influenza A virus has clinical presentation ranging from mild flu like illness to severe lung injury and acute respiratory distress syndrome (ARDS. The aim of our study was to compare the demographic characteristics, clinical presentation, and mortality of critically ill patients with (H1N1+ and without H1N1 infection (H1N1-. We retrospectively analyzed medical charts of patients admitted in "Swine Flu ICU" with ARDS from August 2009 to May 2010. Real-time reverse transcriptase polymerase chain reaction (RT-PCR assay was used for detection of H1N1 virus in the respiratory specimens. Clinical data from 106 (H1N1 , 45; H1N1+, 61 patients was collected and compared. Mean delay in presentation to our hospital was 5.7 ± 3.1 days and co-morbidities were present in two-fifth of the total admissions. Sequential Organ Failure Assessment (SOFA score of patients with and without H1N1 infection was comparable; 7.8 ± 3.5 and 6.6 ± 3.1 on day 1 and 7.2 ± 4.5 and 6.5 ± 3.1 on day 3, respectively. H1N1+ patients were relatively younger in age (34.2 ± 12.9 years vs. 42.8 ± 18.1, P = 0.005 but presented with significantly lower PaO 2 :FiO 2 ratio (87.3 ± 48.7 vs. 114 ± 51.7 in comparison to those who subsequently tested as H1N1 . The total leucocyte counts were significantly lower in H1N1+ patients during the first four days of illness but incidence of renal failure (P = 0.02 was higher in H1N1+ patients. The mortality in both the groups was high (H1N1+, 77%; H1N1, 68% but comparable. There was a mean delay of 5.7 ± 3.1 days in initiation of antivirals. Patients with H1N1 infection were relatively younger in age and with a significantly higher incidence of refractory hypoxia and acute renal failure. Mortality from ARDS reported in our study in both the groups was high but comparable.

A historical perspective of influenza A(H1N2) virus.

Science.gov (United States)

Komadina, Naomi; McVernon, Jodie; Hall, Robert; Leder, Karin

2014-01-01

The emergence and transition to pandemic status of the influenza A(H1N1)A(H1N1)pdm09) virus in 2009 illustrated the potential for previously circulating human viruses to re-emerge in humans and cause a pandemic after decades of circulating among animals. Within a short time of the initial emergence of A(H1N1)pdm09 virus, novel reassortants were isolated from swine. In late 2011, a variant (v) H3N2 subtype was isolated from humans, and by 2012, the number of persons infected began to increase with limited person-to-person transmission. During 2012 in the United States, an A(H1N2)v virus was transmitted to humans from swine. During the same year, Australia recorded its first H1N2 subtype infection among swine. The A(H3N2)v and A(H1N2)v viruses contained the matrix protein from the A(H1N1)pdm09 virus, raising the possibility of increased transmissibility among humans and underscoring the potential for influenza pandemics of novel swine-origin viruses. We report on the differing histories of A(H1N2) viruses among humans and animals.

Polymerase Discordance in Novel Swine Influenza H3N2v Constellations Is Tolerated in Swine but Not Human Respiratory Epithelial Cells

Science.gov (United States)

Powell, Joshua D.; Dlugolenski, Daniel; Nagy, Tamas; Gabbard, Jon; Lee, Christopher; Tompkins, Stephen M.; Tripp, Ralph A.

2014-01-01

Swine-origin H3N2v, a variant of H3N2 influenza virus, is a concern for novel reassortment with circulating pandemic H1N1 influenza virus (H1N1pdm09) in swine because this can lead to the emergence of a novel pandemic virus. In this study, the reassortment prevalence of H3N2v with H1N1pdm09 was determined in swine cells. Reassortants evaluated showed that the H1N1pdm09 polymerase (PA) segment occurred within swine H3N2 with ∼80% frequency. The swine H3N2-human H1N1pdm09 PA reassortant (swH3N2-huPA) showed enhanced replication in swine cells, and was the dominant gene constellation. Ferrets infected with swH3N2-huPA had increased lung pathogenicity compared to parent viruses; however, swH3N2-huPA replication in normal human bronchoepithelial cells was attenuated - a feature linked to expression of IFN-β and IFN-λ genes in human but not swine cells. These findings indicate that emergence of novel H3N2v influenza constellations require more than changes in the viral polymerase complex to overcome barriers to cross-species transmission. Additionally, these findings reveal that while the ferret model is highly informative for influenza studies, slight differences in pathogenicity may not necessarily be indicative of human outcomes after infection. PMID:25330303

Antivirals Use During the Pandemic H1N1 2009 Outbreak

Centers for Disease Control (CDC) Podcasts

2012-01-23

Charisma Atkins, CDC public health analyst, discusses antiviral use during the 2009 H1N1 pandemic flu outbreak.  Created: 1/23/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 1/23/2012.

Polymerase discordance in novel swine influenza H3N2v constellations is tolerated in swine but not human respiratory epithelial cells.

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Joshua D Powell

Full Text Available Swine-origin H3N2v, a variant of H3N2 influenza virus, is a concern for novel reassortment with circulating pandemic H1N1 influenza virus (H1N1pdm09 in swine because this can lead to the emergence of a novel pandemic virus. In this study, the reassortment prevalence of H3N2v with H1N1pdm09 was determined in swine cells. Reassortants evaluated showed that the H1N1pdm09 polymerase (PA segment occurred within swine H3N2 with ∼ 80% frequency. The swine H3N2-human H1N1pdm09 PA reassortant (swH3N2-huPA showed enhanced replication in swine cells, and was the dominant gene constellation. Ferrets infected with swH3N2-huPA had increased lung pathogenicity compared to parent viruses; however, swH3N2-huPA replication in normal human bronchoepithelial cells was attenuated - a feature linked to expression of IFN-β and IFN-λ genes in human but not swine cells. These findings indicate that emergence of novel H3N2v influenza constellations require more than changes in the viral polymerase complex to overcome barriers to cross-species transmission. Additionally, these findings reveal that while the ferret model is highly informative for influenza studies, slight differences in pathogenicity may not necessarily be indicative of human outcomes after infection.

Mitigation approaches to combat the flu pandemic.

Science.gov (United States)

Chawla, Raman; Sharma, Rakesh Kumar; Madaan, Deepali; Dubey, Neha; Arora, Rajesh; Goel, Rajeev; Singh, Shefali; Kaushik, Vinod; Singh, Pankaj Kumar; Chabbra, Vivek; Bhardwaj, Janak Raj

2009-07-01

Management of flu pandemic is a perpetual challenge for the medical fraternity since time immemorial. Animal to human transmission has been observed thrice in the last century within an average range of 11-39 years of antigenic recycling. The recent outbreak of influenza A (H1N1, also termed as swine flu), first reported in Mexico on April 26, 2009, occurred in the forty first year since last reported flu pandemic (July 1968). Within less than 50 days, it has assumed pandemic proportions (phase VI) affecting over 76 countries with 163 deaths/35,928 cases (as on 15(th) June 2009). It indicated the re-emergence of genetically reassorted virus having strains endemic to humans, swine and avian (H5N1). The World Health Organisation (WHO) member states have already pulled up their socks and geared up to combat such criticalities. Earlier outbreaks of avian flu (H5N1) in different countries led WHO to develop pandemic preparedness strategies with national/regional plans on pandemic preparedness. Numerous factors related to climatic conditions, socio-economic strata, governance and sharing of information/logistics at all levels have been considered critical indicators in monitoring the dynamics of escalation towards a pandemic situation.The National Disaster Management Authority (NDMA), Government of India, with the active cooperation of UN agencies and other stakeholders/experts has formulated a concept paper on role of nonhealth service providers during pandemics in April 2008 and released national guidelines - management of biological disasters in July 2008. These guidelines enumerate that the success of medical management endeavors like pharmaceutical (anti-viral Oseltamivir and Zanamivir therapies), nonpharmaceutical interventions and vaccination development etc., largely depends on level of resistance offered by mutagenic viral strain and rationale use of pharmaco therapeutic interventions. This article describes the mitigation approach to combat flu pandemic with

Spread of H1N1 within Households

Centers for Disease Control (CDC) Podcasts

2010-03-29

This podcast describes an investigation into how H1N1 was spreading within households during the initial days of the pandemic in Texas. CDC's Dr. Oliver Morgan discusses what investigators learned about the role that children played in introducing the virus into households and spreading flu.  Created: 3/29/2010 by Emerging Infectious Diseases.   Date Released: 3/29/2010.

Comparison of two H1N2 swine influenza A viruses from disease outbreaks in pigs in Sweden during 2009 and 2010.

Science.gov (United States)

Metreveli, Giorgi; Emmoth, Eva; Zohari, Siamak; Bálint, Adám; Widén, Frederik; Muradrasoli, Shaman; Wallgren, Per; Belák, Sándor; Leblanc, Neil; Berg, Mikael; Kiss, István

2011-04-01

The influenza A virus subtypes H1N1, H1N2 and H3N2 are prevalent in pig populations worldwide. In the present study, two relatively uncommon swine influenza virus (SIV) H1N2 subtypes, isolated in Sweden in 2009 and 2010, were compared regarding their molecular composition and biological characteristics. The differences regarding markers purportedly related to pathogenicity, host adaptation or replication efficiency. They included a truncated PB1-F2 protein in the earlier isolate but a full length version in the more recent one; differences in the number of haemagglutinin glycosylation sites, including a characteristic human one; and a nuclear export protein with altered export signal. Of particular interest, the NS1 amino acid sequence of swine H1N2-2009 and 2010 has a 'unique or very unusual' PDZ binding domain (RPKV) at the C-terminal of the protein, a motif that has been implicated as a virulence marker. Concerning biological properties, these viruses reached lower titre and showed reduced cytopathogenicity in MDCK cells compared with an avian-like H1N1 isolate A/swine/Lidkoping/1193/2002 belonging to the same lineage as the 2009 and 2010 isolates. The findings should contribute to better understanding of factors related to the survival/extinction of this uncommon reassortant variant.

Epidemics and the politics of knowledge: contested narratives in Egypt's H1N1 response.

Science.gov (United States)

Leach, Melissa; Tadros, Mariz

2014-01-01

This article explores the politics of knowledge involved in understanding and responding to epidemics in an era of global health governance and biosecurity. It develops and applies an approach focused on how multiple, competing narratives about epidemics are constructed, mobilized and interact, and selectively justify pathways of intervention and response. A detailed ethnographic case study of national and local responses to H1N1 influenza, so-called swine flu, in Egypt reveals how global narratives were reworked by powerful actors in a particular political context, suppressing and delegitimizing the alternative narratives of the Zabaleen (Coptic Christian) people whose lives and livelihoods centered on raising pigs and working with them to control urban waste. The case study illustrates important ways in which geographies and politics of blame around epidemics emerge and are justified, their political contexts and consequences, and how they may feed back to shape the dynamics of disease itself.

Influenza A (H1N1) neuraminidase inhibitors from Vitis amurensis

DEFF Research Database (Denmark)

Nguyen, Ngoc Anh; Dao, Trong Tuan; Tung, Bui Thanh

2011-01-01

Recently, a novel H1N1 influenza A virus (H1N1/09 virus) was identified and considered a strong candidate for a novel influenza pandemic. As part of an ongoing anti-influenza screening programme on natural products, eight oligostilbenes were isolated as active principles from the methanol extract...... of Vitis amurensis. This manuscript reports the isolation, structural elucidation, and anti-viral activities of eight compounds on various neuraminidases from influenza A/PR/8/34 (H1N1), novel swine-origin influenza A (H1N1), and oseltamivir-resistant novel H1N1 (H274Y) expressed in 293T cells...

Identification of cross-reacting T-cell epitopes in structural and non-structural proteins of swine and pandemic H1N1 influenza A virus strains in pigs

DEFF Research Database (Denmark)

Baratelli, Massimiliano; Pedersen, Lasse Eggers; Trebbien, Ramona

2017-01-01

Heterologous protection against swine influenza viruses (SwIVs) of different lineages is an important concern for the pig industry. Cross-protection between 'avian-like' H1N1 and 2009 pandemic H1N1 lineages has been observed previously, indicating the involvement of cross-reacting T-cells. Here...

Pathogenic characteristics of a novel triple-reasserted H1N2 swine influenza virus.

Science.gov (United States)

Liu, Huili; Tao, Jie; Zhang, Pengchao; Yin, Xiuchen; Ha, Zhuo; Zhang, Chunling

2016-07-01

A novel triple reasserted H1N2 virus A/swine/Shanghai/1/2007 (SH07) was isolated from nasal swabs of weaned pig showing clinical symptoms of coughing and sneezing. To explore the virus characteristics, mice, chickens and pigs were selected for pathogenicity study. Pigs inoculated intranasally with 10(6) TCID50 SH07 showed clinical symptoms with coughing and sneezing, but no death. The virus nuclear acid was detected in many tissues using real-time PCR, which was mainly distributed in respiratory system particularly in the lungs. The virus was low-pathogenic to chickens with 10(6) TCID50 dose inoculation either via intramuscular or intranasal routes. However virus nuclear acid detection and virus isolation confirmed that the virus can also be found in nasal and rectum. When virus was inoculated into mice by intramuscular or intranasal routes we observed 100% and 80% lethality respectively. The third generation of samples passaged on MDCK cell were SIV positive in indirect immunofluorescence assay (IFA) using antiserum against H1N2 SIV. Furthermore, the lungs of mice showed obvious lesion with interstitial pneumonia. Data in our study suggest that SH07 is preferentially pathogenic to mammals rather than birds although it is a reasserting virus with the fragments from swine, human and avian origin. Copyright © 2016 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

Development of a diagnostic kit for Tamiflu-resistant influenza A (H1N1)

International Nuclear Information System (INIS)

Jung, I. L.; Hong, S. W.

2012-01-01

Swine influenza A, which has been pandemic worldwide since 2009, is a new type virus derived from A type influenza. Although some drugs against the contageous disease, such as relenza and tamiflu, have been commercialized, those drug resistant viruses could be also followed by the wide usage of drugs. For examples, Tamiflu-resistant viruses, the mutant type viruses, can not be cured by the treatment of tamiflu anymore. Thus, a quick diagnosis for the wild type (tamiflu-sensitive) and mutant (tamiflu-resistant) virus would be essential in order to prevent the wide spread of viruses. In spite of that, unfortunately, very few studies have been conducted until now. If we could tell the differences between tamiflu-resistant and -sensitive patients using by the proper diagnostic kit, not only patient specific treatment would be possible, but also the spread of viruses would be effectively prevented. Currently used detection methods for the swine influenza A H1N1, which were originated from CDC, USA, can not detect the tamiflu-resistant swine influenza A H1N1, but only can detect tamiflu-sensitive wine influenza A H1N1. In this study, all the primers for the detection of swInfA, swH1, MP and NA (neuraminidase) have been developed in order to detect both tamiflu-resistant and tamiflu-sensitive swine influenza A H1N1s simultaneously, and then, new multiplex RT-PCR methods has been established

Development of a diagnostic kit for Tamiflu-resistant influenza A (H1N1)

Energy Technology Data Exchange (ETDEWEB)

Jung, I. L.; Hong, S. W.

2012-01-15

Swine influenza A, which has been pandemic worldwide since 2009, is a new type virus derived from A type influenza. Although some drugs against the contageous disease, such as relenza and tamiflu, have been commercialized, those drug resistant viruses could be also followed by the wide usage of drugs. For examples, Tamiflu-resistant viruses, the mutant type viruses, can not be cured by the treatment of tamiflu anymore. Thus, a quick diagnosis for the wild type (tamiflu-sensitive) and mutant (tamiflu-resistant) virus would be essential in order to prevent the wide spread of viruses. In spite of that, unfortunately, very few studies have been conducted until now. If we could tell the differences between tamiflu-resistant and -sensitive patients using by the proper diagnostic kit, not only patient specific treatment would be possible, but also the spread of viruses would be effectively prevented. Currently used detection methods for the swine influenza A H1N1, which were originated from CDC, USA, can not detect the tamiflu-resistant swine influenza A H1N1, but only can detect tamiflu-sensitive wine influenza A H1N1. In this study, all the primers for the detection of swInfA, swH1, MP and NA (neuraminidase) have been developed in order to detect both tamiflu-resistant and tamiflu-sensitive swine influenza A H1N1s simultaneously, and then, new multiplex RT-PCR methods has been established.

Protection of human influenza vaccines against a reassortant swine influenza virus of pandemic H1N1 origin using a pig model.

Science.gov (United States)

Arunorat, Jirapat; Charoenvisal, Nataya; Woonwong, Yonlayong; Kedkovid, Roongtham; Jittimanee, Supattra; Sitthicharoenchai, Panchan; Kesdangsakonwut, Sawang; Poolperm, Pariwat; Thanawongnuwech, Roongroje

2017-10-01

Since the pandemic H1N1 emergence in 2009 (pdmH1N1), many reassortant pdmH1N1 viruses emerged and found circulating in the pig population worldwide. Currently, commercial human subunit vaccines are used commonly to prevent the influenza symptom based on the WHO recommendation. In case of current reassortant swine influenza viruses transmitting from pigs to humans, the efficacy of current human influenza vaccines is of interest. In this study, influenza A negative pigs were vaccinated with selected commercial human subunit vaccines and challenged with rH3N2. All sera were tested with both HI and SN assays using four representative viruses from the surveillance data in 2012 (enH1N1, pdmH1N1, rH1N2 and rH3N2). The results showed no significant differences in clinical signs and macroscopic and microscopic findings among groups. However, all pig sera from vaccinated groups had protective HI titers to the enH1N1, pdmH1N1 and rH1N2 at 21DPV onward and had protective SN titers only to pdmH1N1and rH1N2 at 21DPV onward. SN test results appeared more specific than those of HI tests. All tested sera had no cross-reactivity against the rH3N2. Both studied human subunit vaccines failed to protect and to stop viral shedding with no evidence of serological reaction against rH3N2. SIV surveillance is essential for monitoring a novel SIV emergence potentially for zoonosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Integrative study of pandemic A/H1N1 influenza infections: design and methods of the CoPanFlu-France cohort

Directory of Open Access Journals (Sweden)

Lapidus Nathanael

2012-06-01

Full Text Available Abstract Background The risk of influenza infection depends on biological characteristics, individual or collective behaviors and the environmental context. The Cohorts for Pandemic Influenza (CoPanFlu France study was set up in 2009 after the identification of the novel swine-origin A/H1N1 pandemic influenza virus. This cohort of 601 households (1450 subjects representative for the general population aims at using an integrative approach to study the risk and characteristics of influenza infection as a complex combination of data collected from questionnaires regarding sociodemographic, medical, behavioral characteristics of subjects and indoor environment, using biological samples or environmental databases. Methods/Design Households were included between December 2009 and July 2010. The design of this study relies on systematic follow-up visits between influenza seasons and additional visits during influenza seasons, when an influenza-like illness is detected in a household via an active surveillance system. During systematic visits, a nurse collects individual and environmental data on questionnaires and obtains blood samples from all members of the household. When an influenza-like-illness is detected, a nurse visits the household three times during the 12 following days, and collects data on questionnaires regarding exposure and symptoms, and biological samples (including nasal swabs from all subjects in the household. The end of the follow-up period is expected in fall 2012. Discussion The large amount of data collected throughout the follow-up will permit a multidisciplinary study of influenza infections. Additional data is being collected and analyzed in this ongoing cohort. The longitudinal analysis of these households will permit integrative analyses of complex phenomena such as individual, collective and environmental risk factors of infection, routes of transmission, or determinants of the immune response to infection or vaccination.

Mitigation Approaches to Combat the Flu Pandemic

Science.gov (United States)

Chawla, Raman; Sharma, Rakesh Kumar; Madaan, Deepali; Dubey, Neha; Arora, Rajesh; Goel, Rajeev; Singh, Shefali; Kaushik, Vinod; Singh, Pankaj Kumar; Chabbra, Vivek; Bhardwaj, Janak Raj

2009-01-01

Management of flu pandemic is a perpetual challenge for the medical fraternity since time immemorial. Animal to human transmission has been observed thrice in the last century within an average range of 11-39 years of antigenic recycling. The recent outbreak of influenza A (H1N1, also termed as swine flu), first reported in Mexico on April 26, 2009, occurred in the forty first year since last reported flu pandemic (July 1968). Within less than 50 days, it has assumed pandemic proportions (phase VI) affecting over 76 countries with 163 deaths/35,928 cases (as on 15th June 2009). It indicated the re-emergence of genetically reassorted virus having strains endemic to humans, swine and avian (H5N1). The World Health Organisation (WHO) member states have already pulled up their socks and geared up to combat such criticalities. Earlier outbreaks of avian flu (H5N1) in different countries led WHO to develop pandemic preparedness strategies with national/regional plans on pandemic preparedness. Numerous factors related to climatic conditions, socio-economic strata, governance and sharing of information/logistics at all levels have been considered critical indicators in monitoring the dynamics of escalation towards a pandemic situation. The National Disaster Management Authority (NDMA), Government of India, with the active cooperation of UN agencies and other stakeholders/experts has formulated a concept paper on role of nonhealth service providers during pandemics in April 2008 and released national guidelines - management of biological disasters in July 2008. These guidelines enumerate that the success of medical management endeavors like pharmaceutical (anti-viral Oseltamivir and Zanamivir therapies), nonpharmaceutical interventions and vaccination development etc., largely depends on level of resistance offered by mutagenic viral strain and rationale use of pharmaco therapeutic interventions. This article describes the mitigation approach to combat flu pandemic with its

Triple-reassortant influenza A virus with H3 of human seasonal origin, NA of swine origin, and internal A(H1N1) pandemic 2009 genes is established in Danish pigs

DEFF Research Database (Denmark)

Krog, Jesper Schak; Hjulsager, Charlotte Kristiane; Larsen, Michael Albin

2017-01-01

This report describes a triple-reassortant influenza A virus with a HA that resembles H3 of human seasonal influenza from 2004 to 2005, N2 from influenza A virus already established in swine, and the internal gene cassette from A(H1N1)pdm09 has spread in Danish pig herds. The virus has been detec...

Swine-Flu Plans Put E-Learning in the Spotlight

Science.gov (United States)

Davis, Michelle R.; Ash, Katie

2009-01-01

Last school year, many educators were caught unprepared when schools closed in response to cases of swine flu. This time around, both the federal government and school districts are putting specific online-learning measures in place to get ready for possible closures or waves of teacher and student absences because of a flu outbreak. To prepare…

Attitudinal Modeling of Affect, Behavior and Cognition: Semantic Mining of Disaster Text Corpus

Science.gov (United States)

2010-10-01

known as H1N1, H1N2 , H3N1, H3N2, and H2N3. Swine influenza virus is common throughout pig populations worldwide. Transmission of the virus from pigs to...large region, for instance a continent, or even worldwide. Swine Flu Swine influenza (also called pig influenza , swine flu, hog flu and pig flu) is an...infection by any one of several types of swine influenza virus. Swine influenza virus (SIV) or S-OIV (swine- origin influenza virus) is any strain

Avian Flu (H7N9) in China

Science.gov (United States)

... Mobile Apps RSS Feeds Avian Flu (H7N9) in China Recommend on Facebook Tweet Share Compartir Warning - Level ... of H7N9 have been reported outside of mainland China but most of these infections have occurred among ...

MODEL SEIR UNTUK EPIDEMI FLU BABI PADA POPULASI BABI DENGAN LAJU KONTAK JENUH

Directory of Open Access Journals (Sweden)

M Kharis

2012-09-01

Full Text Available Babi merupakan inang alami dari virus influensa yang secara anatomis, fisiologis, dan imunitas mirip (similar dengan yang ada pada manusia. Virus influenza subtipe A yang ada pada manusia yaitu H1N1, H3N2 dan H1N2 merupakan enzootic pada populasi babi di dunia. babi dapat terinfeksi oleh turunan-turunan virus influenza tipe A dari manusia maupun dari burung dan dalam hal ini dianggap sebagai inang sementara (Intermediate hosts dari turunan-turunan virus flu babi yang berpotensi menyebabkan epidemi bahkan pandemi. Evolusi antigenik dari virus influenza pada babi terjadi dengan laju sekitar 6 kali lebih lambat dibandingkan dengan virus influenza pada manusia. Dalam tulisan ini akan dikaji model matematika untuk epidemi flu babi pada populasi babi. Model yang diberikan merupakan model deterministik dengan laju kontak jenuh yang merupakan perumuman dari laju kontak standar. Perumuman ini dinyatakan dengan adanya probabilitas suatu individu melakukan kontak yang dinyatakan sebagai suatu fungsi dari populasi. Pengkajian yang dilakukan meliputi penentuan titik ekuilibrium model matematika dan analisa kestabilannya. Diharapkan hasil kajian ini dapat bermanfaat dalam penanggulangan wabah flu babi pada sumber utama yaitu populasi babi sehingga dapat dilakukan pencegahan sebelum mewabah di populasi manusia. Pigs are a natural host of influenza virus that are similar anatomically, physiologically, and immunity which in humans. Influenza viruses of A subtype in humans are H1N1, H3N2 and H1N2. They are enzootic in the swine population in the world. Pigs can be infected by strains of type A influenza viruses from humans or from birds. Pigs are considered as a temporary host (intermediate hosts of the derivatives of the swine flu virus that has the potential to cause epidemics and even pandemics. Antigenic evolution of influenza viruses in pigs occurred at rate about 6 times slower than the influenza viruses in humans. In this paper the mathematical model

Appearance of reassortant European avian-origin H1 influenza A viruses of swine in Vietnam.

Science.gov (United States)

Takemae, N; Nguyen, P T; Le, V T; Nguyen, T N; To, T L; Nguyen, T D; Pham, V P; Vo, H V; Le, Q V T; Do, H T; Nguyen, D T; Uchida, Y; Saito, T

2018-03-06

Three subtypes-H1N1, H1N2 and H3N2-of influenza A viruses of swine (IAVs-S) are currently endemic in swine worldwide, but there is considerable genotypic diversity among each subtype and limited geographical distribution. Through IAVs-S monitoring in Vietnam, two H1N2 influenza A viruses were isolated from healthy pigs in Ba Ria-Vung Tau Province, Southern Vietnam, on 2 December 2016. BLAST and phylogenetic analyses revealed that their HA and NA genes were derived from those of European avian-like H1N2 IAVs-S that contained avian-origin H1 and human-like N2 genes, and were particularly closely related to those of IAVs-S circulating in the Netherlands, Germany or Denmark. In addition, the internal genes of these Vietnamese isolates were derived from human A(H1N1)pdm09 viruses, suggesting that the Vietnamese H1N2 IAVs-S are reassortants between European H1N2 IAVs-S and human A(H1N1)pdm09v. The appearance of European avian-like H1N2 IAVs-S in Vietnam marks their first transmission outside Europe. Our results and statistical analyses of the number of live pigs imported into Vietnam suggest that the European avian-like H1N2 IAVs-S may have been introduced into Vietnam with their hosts through international trade. These findings highlight the importance of quarantining imported pigs to impede the introduction of new IAVs-S. © 2018 Blackwell Verlag GmbH.

Chest Radiographic Findings of Novel Swine-Origin Influenza A (H1N1) Virus Infection in Children

Energy Technology Data Exchange (ETDEWEB)

Bae, So Young; Hong, Eun Sook; Paik, Sang Hyun; Park, Seong Jin; Cha, Jang Gyu; Lee, Hae Kyung [Dept. of Radiology, Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Jang, Yun Woo [Dept. of Radiology, Soonchunhyang University Hospital, Seoul (Korea, Republic of)

2011-06-15

To analyze chest radiographic findings in children infected with laboratory confirmed novel swine-origin influenza A (H1N1) virus. Three hundred seventy-two out of 2,014 children with laboratory confirmed H1N1 infection and who also underwent a chest radiograph from September to November 2009 were enrolled in this study. Patients were divided into in-patients, out-patients, and patients with co-infections and further subdivided into with underlying disease and without underlying disease as well as age (<2 years old, 2-5 years, 5-10 years, 10-18 years old). The initial radiographs were evaluated for radiographic findings and the anatomic distribution of abnormalities. The initial radiographs were abnormal in 154 (41.39%) patients. The predominant radiographic findings were peribronchial wall opacity found in 85 (22.84%) patients and hyperinflation observed in 69 (18.54%) patients. Further, 75 (71.42%) patients exhibited central predominance and the right lower lung zone was also commonly involved. There were statistically significant differences in the radiological findings between in-patient and out-patient groups. However, there were no significant differences in the radiographic findings between in-patients and the co-infection group with respect the presence of underlying disease and age. Initial radiographs of children with laboratory confirmed H1N1 virus were abnormal in 41.39% of cases. The common radiographic findings included peribronchial opacities, hyperinflation, lower lung zonal distribution, and central predominance

Temperature sensitivity on growth and/or replication of H1N1, H1N2 and H3N2 influenza A viruses isolated from pigs and birds in mammalian cells.

Science.gov (United States)

Massin, Pascale; Kuntz-Simon, Gaëlle; Barbezange, Cyril; Deblanc, Céline; Oger, Aurélie; Marquet-Blouin, Estelle; Bougeard, Stéphanie; van der Werf, Sylvie; Jestin, Véronique

2010-05-19

Influenza A viruses have been isolated from a wide range of animal species, aquatic birds being the reservoir for their genetic diversity. Avian influenza viruses can be transmitted to humans, directly or indirectly through an intermediate host like pig. This study aimed to define in vitro conditions that could prove useful to evaluate the potential of influenza viruses to adapt to a different host. Growth of H1N1, H1N2 and H3N2 influenza viruses belonging to different lineages isolated from birds or pigs prior to 2005 was tested on MDCK or NPTr cell lines in the presence or absence of exogenous trypsin. Virus multiplication was compared at 33, 37 and 40 degrees C, the infection site temperatures in human, swine and avian hosts, respectively. Temperature sensitivity of PB2-, NP- and M-RNA replication was also tested by quantitative real-time PCR. Multiplication of avian viruses was cold-sensitive, whatever cell type. By contrast, temperature sensitivity of swine viruses was found to depend on the virus and the host cell: for an H1N1 swine isolate from 1982, multiplication was cold-sensitive on NPTr cells and undetectable at 40 degrees C. From genetic analyses, it appears that temperature sensitivity could involve other residues than PB2 residue 627 and could affect other steps of the replication cycle than replication. Copyright 2009 Elsevier B.V. All rights reserved.

Different evolutionary trends of swine H1N2 influenza viruses in Italy compared to European viruses.

Science.gov (United States)

Moreno, Ana; Gabanelli, Elena; Sozzi, Enrica; Lelli, Davide; Chiapponi, Chiara; Ciccozzi, Massimo; Zehender, Gianguglielmo; Cordioli, Paolo

2013-12-01

European H1N2 swine influenza viruses (EU H1N2SIVs) arose from multiple reassortment events among human H1N1, human H3N2, and avian influenza viruses. We investigated the evolutionary dynamics of 53 Italian H1N2 strains by comparing them with EU H1N2 SIVs. Hemagglutinin (HA) phylogeny revealed Italian strains fell into four groups: Group A and B (41 strains) had a human H1 similar to EU H1N2SIVs, which probably originated in 1986. However Group B (38 strains) formed a subgroup that had a two-amino acid deletion at positions 146/147 in HA. Group C (11 strains) contained an avian H1 that probably originated in 1996, and Group D (1 strain) had an H1 characteristic of the 2009 pandemic strain. Neuraminidase (NA) phylogeny suggested a series of genomic reassortments had occurred. Group A had an N2 that originated from human H3N2 in the late 1970s. Group B had different human N2 that most likely arose from a reassortment with the more recent human H3N2 virus, which probably occurred in 2000. Group C had an avian-like H1 combined with an N2 gene from one of EU H1N2SIVs, EU H3N2SIVs or Human H3N2. Group D was part of the EU H3N2SIVs clade. Although selection pressure for HA and NA was low, several positively selected sites were identified in both proteins, some of which were antigenic, suggesting selection influenced the evolution of SIV. The data highlight different evolutionary trends between European viruses and currently circulating Italian B strains and show the establishment of reassortant strains involving human viruses in Italian pigs.

H1N1, globalization and the epidemiology of inequality.

Science.gov (United States)

Sparke, Matthew; Anguelov, Dimitar

2012-07-01

This paper examines the lessons learned from the 2009 H1N1 pandemic in relation to wider work on globalization and the epidemiology of inequality. The media attention and economic resources diverted to the threats posed by H1N1 were significant inequalities themselves when contrasted with weaker responses to more lethal threats posed by other diseases associated with global inequality. However, the multiple inequalities revealed by H1N1 itself in 2009 still provide important insights into the future of global health in the context of market-led globalization. These lessons relate to at least four main forms of inequality: (1) inequalities in blame for the outbreak in the media; (2) inequalities in risk management; (3) inequalities in access to medicines; and (4) inequalities encoded in the actual emergence of new flu viruses. Copyright © 2011 Elsevier Ltd. All rights reserved.

Different neuraminidase inhibitor susceptibilities of human H1N1, H1N2, and H3N2 influenza A viruses isolated in Germany from 2001 to 2005/2006.

Science.gov (United States)

Bauer, Katja; Richter, Martina; Wutzler, Peter; Schmidtke, Michaela

2009-04-01

In the flu season 2005/2006 amantadine-resistant human influenza A viruses (FLUAV) of subtype H3N2 circulated in Germany. This raises questions on the neuraminidase inhibitor (NAI) susceptibility of FLUAV. To get an answer, chemiluminescence-based neuraminidase inhibition assays were performed with 51 H1N1, H1N2, and H3N2 FLUAV isolated in Germany from 2001 to 2005/2006. According to the mean IC(50) values (0.38-0.91 nM for oseltamivir and 0.76-1.13 nM for zanamivir) most H1N1 and H3N2 FLUAV were NAI-susceptible. But, about four times higher zanamivir concentrations were necessary to inhibit neuraminidase activity of H1N2 viruses. Two H1N1 isolates were less susceptible to both drugs in NA inhibition as well as virus yield reduction assays. Results from sequence analysis of viral hemagglutinin and neuraminidase genes and evolutionary analysis of N2 gene revealed (i) different subclades for N2 in H1N2 and H3N2 FLUAV that could explain the differences in zanamivir susceptibility among these viruses and (ii) specific amino acid substitutions in the neuraminidase segment of the two less NAI-susceptible H1N1 isolates. One H3N2 was isolate proved to be a mixture of a NA deletion mutant and full-length NA viruses.

Avoiding the Flu

Science.gov (United States)

... of this page please turn Javascript on. Feature: Flu Avoiding the Flu Past Issues / Fall 2009 Table of Contents Children ... should still get the 2009 H1N1 vaccine. H1N1 Flu: Who Should Be Vaccinated First The Centers for ...

Underreporting of 2009 H1N1 Influenza Cases

Centers for Disease Control (CDC) Podcasts

Influenza cases are difficult to track because many people don't go to the doctor or get tested for flu when they're sick. The first months of the 2009 H1N1 influenza pandemic were no different. In this podcast, CDC's Dr. Carrie Reed discusses a study in the December issue of Emerging Infectious Diseases that looked at the actual number of cases reported and estimated the true number of cases when correcting for underreporting.

Modelling the Growth of Swine Flu

Science.gov (United States)

Thomson, Ian

2010-01-01

The spread of swine flu has been a cause of great concern globally. With no vaccine developed as yet, (at time of writing in July 2009) and given the fact that modern-day humans can travel speedily across the world, there are fears that this disease may spread out of control. The worst-case scenario would be one of unfettered exponential growth.…

A seroepidemiological study of pandemic A/H1N1(2009) influenza in a rural population of Mali.

Science.gov (United States)

Koita, O A; Sangare, L; Poudiougou, B; Aboubacar, B; Samake, Y; Coulibaly, T; Pronyk, P; Salez, N; Kieffer, A; Ninove, L; Flahault, A; de Lamballerie, X

2012-10-01

The swine-origin H1N1 influenza A virus (pH1N1(2009)) started to circulate worldwide in 2009, and cases were notified in a number of sub-Saharan African countries. However, no epidemiological data allowing estimation of the epidemic burden were available in this region, preventing comprehensive comparisons with other parts of the world. The CoPanFlu-Mali programme studied a cohort of 202 individuals living in the rural commune of Dioro (southern central Mali). Pre-pandemic and post-pandemic paired sera (sampled in 2006 and April 2010, respectively) were tested by the haemagglutination inhibition (HI) method. Different estimates of pH1N1(2009) infection during the 2009 first epidemic wave were used (increased prevalence of HI titre of ≥1/40 or ≥1/80, seroconversions) and provided convergent attack rate values (12.4-14.9%), the highest values being observed in the 0-19-year age group (16.0-18.4%). In all age groups, pre-pandemic HI titres of ≥1/40 were associated with complete absence of seroconversion; and geometric mean titres were 20 in others. Important variations in seroconversion rate existed among the different villages investigated. Despite limitations resulting from the size and composition of the sample analysed, this study provides strong evidence that the impact of the pH1N1(2009) first wave was more important than previously believed, and that the determinants of the epidemic spread in sub-Saharan populations were quite different from those observed in developed countries. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.

Rheumatoid arthritis and Swine influenza vaccine: a case report.

Science.gov (United States)

Basra, Gurjot; Jajoria, Praveen; Gonzalez, Emilio

2012-01-01

Rheumatoid arthritis (RA) is the most common chronic inflammatory joint disease. Multiple scientific articles have documented that vaccinations for influenza, MMR, and HBV, to name a few, could be triggers of RA in genetically predisposed individuals. However, there is limited data regarding the association of swine flu vaccine (H1N1) and RA. We report the case of a Mexican American female who developed RA right after vaccination with H1N1 vaccine. Genetically, RA has consistently been associated with an epitope in the third hypervariable region of the HLA-DR β chains, known as the "shared epitope", which is found primarily in DR4 and DR1 regions. The presence of HLA-DRB1 alleles is associated with susceptibility to RA in Mexican Americans. Hence, certain individuals with the presence of the "shared epitope" may develop RA following specific vaccinations. To our knowledge, this is the first reported case of RA following vaccination with the swine flu vaccine.

Rheumatoid Arthritis and Swine Influenza Vaccine: A Case Report

Directory of Open Access Journals (Sweden)

Gurjot Basra

2012-01-01

Full Text Available Rheumatoid arthritis (RA is the most common chronic inflammatory joint disease. Multiple scientific articles have documented that vaccinations for influenza, MMR, and HBV, to name a few, could be triggers of RA in genetically predisposed individuals. However, there is limited data regarding the association of swine flu vaccine (H1N1 and RA. We report the case of a Mexican American female who developed RA right after vaccination with H1N1 vaccine. Genetically, RA has consistently been associated with an epitope in the third hypervariable region of the HLA-DR chains, known as the “shared epitope”, which is found primarily in DR4 and DR1 regions. The presence of HLA-DRB1 alleles is associated with susceptibility to RA in Mexican Americans. Hence, certain individuals with the presence of the “shared epitope” may develop RA following specific vaccinations. To our knowledge, this is the first reported case of RA following vaccination with the swine flu vaccine.

From where did the 2009 'swine-origin' influenza A virus (H1N1 emerge?

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Armstrong John S

2009-11-01

Full Text Available Abstract The swine-origin influenza A (H1N1 virus that appeared in 2009 and was first found in human beings in Mexico, is a reassortant with at least three parents. Six of the genes are closest in sequence to those of H1N2 'triple-reassortant' influenza viruses isolated from pigs in North America around 1999-2000. Its other two genes are from different Eurasian 'avian-like' viruses of pigs; the NA gene is closest to H1N1 viruses isolated in Europe in 1991-1993, and the MP gene is closest to H3N2 viruses isolated in Asia in 1999-2000. The sequences of these genes do not directly reveal the immediate source of the virus as the closest were from isolates collected more than a decade before the human pandemic started. The three parents of the virus may have been assembled in one place by natural means, such as by migrating birds, however the consistent link with pig viruses suggests that human activity was involved. We discuss a published suggestion that unsampled pig herds, the intercontinental live pig trade, together with porous quarantine barriers, generated the reassortant. We contrast that suggestion with the possibility that laboratory errors involving the sharing of virus isolates and cultured cells, or perhaps vaccine production, may have been involved. Gene sequences from isolates that bridge the time and phylogenetic gap between the new virus and its parents will distinguish between these possibilities, and we suggest where they should be sought. It is important that the source of the new virus be found if we wish to avoid future pandemics rather than just trying to minimize the consequences after they have emerged. Influenza virus is a very significant zoonotic pathogen. Public confidence in influenza research, and the agribusinesses that are based on influenza's many hosts, has been eroded by several recent events involving the virus. Measures that might restore confidence include establishing a unified international administrative

[Predicting spread of new pandemic swine-origin influenza A (H1N1) in local mid-size city: evaluation of hospital bed shortage and effectiveness of vaccination].

Science.gov (United States)

Takeuchi, Shouhei; Kuroda, Yoshiki

2010-01-01

On April 24th, 2009, a new swine-origin influenza A (H1N1) was first reported in Mexico. Japan confirmed cases of the flu on May 9th, and the pandemic in Japan has become full-scale. The Ministry of Health, Labor and Welfare of Japan announced that the first peak of this pandemic was predicted to occur in October, 2009. Therefore, it is most important to predict the progress of this pandemic to be able to use medical resources effectively in Japan. We used a modified susceptible-exposed-infected-recovered (SEIR) model to calculate the number of infected people and hospital bed shortage during this pandemic. In this model, available medical resources were investigated on the basis of four vaccination scenarios. Our model showed that it would take a further six months for the pandemic to peak than was predicted by the Ministry of Health, Labor and Welfare of Japan. Without vaccination, at the peak of the pandemic 23,689 out of 400,000 people would be infected and the hospital bed shortage would reach 7,349 in total. We suggest that mathematical models are strong tools to predict the spread of infectious diseases. According to our model, it is possible to prevent hospital bed shortage by vaccination.

International collaboration to assess the risk of Guillain Barré Syndrome following Influenza A (H1N1) 2009 monovalent vaccines.

Science.gov (United States)

Dodd, Caitlin N; Romio, Silvana A; Black, Steven; Vellozzi, Claudia; Andrews, Nick; Sturkenboom, Miriam; Zuber, Patrick; Hua, Wei; Bonhoeffer, Jan; Buttery, Jim; Crawford, Nigel; Deceuninck, Genevieve; de Vries, Corinne; De Wals, Philippe; Gutierrez-Gimeno, M Victoria; Heijbel, Harald; Hughes, Hayley; Hur, Kwan; Hviid, Anders; Kelman, Jeffrey; Kilpi, Tehri; Chuang, S K; Macartney, Kristine; Rett, Melisa; Lopez-Callada, Vesta Richardson; Salmon, Daniel; Gimenez-Sanchez, Francisco; Sanz, Nuria; Silverman, Barbara; Storsaeter, Jann; Thirugnanam, Umapathi; van der Maas, Nicoline; Yih, Katherine; Zhang, Tao; Izurieta, Hector

2013-09-13

The global spread of the 2009 novel pandemic influenza A (H1N1) virus led to the accelerated production and distribution of monovalent 2009 Influenza A (H1N1) vaccines (pH1N1). This pandemic provided the opportunity to evaluate the risk of Guillain-Barré syndrome (GBS), which has been an influenza vaccine safety concern since the swine flu pandemic of 1976, using a common protocol among high and middle-income countries. The primary objective of this project was to demonstrate the feasibility and utility of global collaboration in the assessment of vaccine safety, including countries both with and without an established infrastructure for vaccine active safety surveillance. A second objective, included a priori, was to assess the risk of GBS following pH1N1 vaccination. The primary analysis used the self-controlled case series (SCCS) design to estimate the relative incidence (RI) of GBS in the 42 days following vaccination with pH1N1 vaccine in a pooled analysis across databases and in analysis using a meta-analytic approach. We found a relative incidence of GBS of 2.42 (95% CI 1.58-3.72) in the 42 days following exposure to pH1N1 vaccine in analysis of pooled data and 2.09 (95% CI 1.28-3.42) using the meta-analytic approach. This study demonstrates that international collaboration to evaluate serious outcomes using a common protocol is feasible. The significance and consistency of our findings support a conclusion of an association between 2009 H1N1 vaccination and GBS. Given the rarity of the event the relative incidence found does not provide evidence in contradiction to international recommendations for the continued use of influenza vaccines. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comparison between pandemic H1N1 2009 influenza pneumonia and seasonal influenza pneumonia in adults

International Nuclear Information System (INIS)

Ishiguro, Takashi; Takayanagi, Noboru; Yoneda, Koichiro

2011-01-01

We compared 126 cases of seasonal influenza pneumonia (seasonal flu) reported between January, 1996 and March, 2009, with 10 cases of laboratory-confirmed pandemic influenza (H1N1) 2009 influenza virus pneumonia (novel flu), based on clinical condition, computed tomography (CT) findings, severity, treatment, and prognosis, to clarify the characteristics of this novel flu. The mean age of subjects was 52.4 years in the novel flu group and 64 years in the seasonal flu group, and novel flu patients were younger than seasonal flu patients. Seasonal flu patients had more underlying diseases than did novel flu patients. The median duration from illness onset to hospitalization was 4 days in both groups. Primary viral pneumonia was present in 70% of novel flu cases and 31% of seasonal flu cases. The proportion of primary virus pneumonia was higher in novel flu patients, and the disease severity of the seasonal flu group was more severe than that of the novel flu group. White blood cell and lymphocyte counts were lower in novel flu patients, and chest CT images showed bilateral shadows and pure ground-glass opacities more frequently in the novel flu cases. There were no differences in treatment, number of days required for the fever to subside, or mortality between the groups. (author)

Outbreak of pandemic influenza A/H1N1 2009 in Nepal.

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Adhikari, Bal Ram; Shakya, Geeta; Upadhyay, Bishnu Prasad; Prakash Kc, Khagendra; Shrestha, Sirjana Devi; Dhungana, Guna Raj

2011-03-23

The 2009 flu pandemic is a global outbreak of a new strain of H1N1 influenza virus. Pandemic influenza A (H1N1) 2009 has posed a serious public health challenge world-wide. Nepal has started Laboratory diagnosis of Pandemic influenza A/H1N1 from mid June 2009 though active screening of febrile travellers with respiratory symptoms was started from April 27, 2009. Out of 609 collected samples, 302 (49.6%) were Universal Influenza A positive. Among the influenza A positive samples, 172(28.3%) were positive for Pandemic influenza A/H1N1 and 130 (21.3%) were Seasonal influenza A. Most of the pandemic cases (53%) were found among young people with ≤ 20 years. Case Fatality Ratio for Pandemic influenza A/H1N1 in Nepal was 1.74%. Upon Molecular characterization, all the isolated pandemic influenza A/H1N1 2009 virus found in Nepal were antigenically and genetically related to the novel influenza A/CALIFORNIA/07/2009-LIKE (H1N1)v type. The Pandemic 2009 influenza virus found in Nepal were antigenically and genetically related to the novel A/CALIFORNIA/07/2009-LIKE (H1N1)v type.

Outbreak of pandemic influenza A/H1N1 2009 in Nepal

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Shrestha Sirjana

2011-03-01

Full Text Available Abstract Background The 2009 flu pandemic is a global outbreak of a new strain of H1N1 influenza virus. Pandemic influenza A (H1N1 2009 has posed a serious public health challenge world-wide. Nepal has started Laboratory diagnosis of Pandemic influenza A/H1N1 from mid June 2009 though active screening of febrile travellers with respiratory symptoms was started from April 27, 2009. Results Out of 609 collected samples, 302 (49.6% were Universal Influenza A positive. Among the influenza A positive samples, 172(28.3% were positive for Pandemic influenza A/H1N1 and 130 (21.3% were Seasonal influenza A. Most of the pandemic cases (53% were found among young people with ≤ 20 years. Case Fatality Ratio for Pandemic influenza A/H1N1 in Nepal was 1.74%. Upon Molecular characterization, all the isolated pandemic influenza A/H1N1 2009 virus found in Nepal were antigenically and genetically related to the novel influenza A/CALIFORNIA/07/2009-LIKE (H1N1v type. Conclusion The Pandemic 2009 influenza virus found in Nepal were antigenically and genetically related to the novel A/CALIFORNIA/07/2009-LIKE (H1N1v type.

Efficacy of a pandemic (H1N1) 2009 virus vaccine in pigs against the pandemic influenza virus is superior to commercially available swine influenza vaccines.

Science.gov (United States)

Loeffen, W L A; Stockhofe, N; Weesendorp, E; van Zoelen-Bos, D; Heutink, R; Quak, S; Goovaerts, D; Heldens, J G M; Maas, R; Moormann, R J; Koch, G

2011-09-28

In April 2009 a new influenza A/H1N1 strain, currently named "pandemic (H1N1) influenza 2009" (H1N1v), started the first official pandemic in humans since 1968. Several incursions of this virus in pig herds have also been reported from all over the world. Vaccination of pigs may be an option to reduce exposure of human contacts with infected pigs, thereby preventing cross-species transfer, but also to protect pigs themselves, should this virus cause damage in the pig population. Three swine influenza vaccines, two of them commercially available and one experimental, were therefore tested and compared for their efficacy against an H1N1v challenge. One of the commercial vaccines is based on an American classical H1N1 influenza strain, the other is based on a European avian H1N1 influenza strain. The experimental vaccine is based on reassortant virus NYMC X179A (containing the hemagglutinin (HA) and neuraminidase (NA) genes of A/California/7/2009 (H1N1v) and the internal genes of A/Puerto Rico/8/34 (H1N1)). Excretion of infectious virus was reduced by 0.5-3 log(10) by the commercial vaccines, depending on vaccine and sample type. Both vaccines were able to reduce virus replication especially in the lower respiratory tract, with less pathological lesions in vaccinated and subsequently challenged pigs than in unvaccinated controls. In pigs vaccinated with the experimental vaccine, excretion levels of infectious virus in nasal and oropharyngeal swabs, were at or below 1 log(10)TCID(50) per swab and lasted for only 1 or 2 days. An inactivated vaccine containing the HA and NA of an H1N1v is able to protect pigs from an infection with H1N1v, whereas swine influenza vaccines that are currently available are of limited efficaciousness. Whether vaccination of pigs against H1N1v will become opportune remains to be seen and will depend on future evolution of this strain in the pig population. Close monitoring of the pig population, focussing on presence and evolution of

Positive Selection on Hemagglutinin and Neuraminidase Genes of H1N1 Influenza Viruses

LENUS (Irish Health Repository)

Li, Wenfu

2011-04-21

Abstract Background Since its emergence in March 2009, the pandemic 2009 H1N1 influenza A virus has posed a serious threat to public health. To trace the evolutionary path of these new pathogens, we performed a selection-pressure analysis of a large number of hemagglutinin (HA) and neuraminidase (NA) gene sequences of H1N1 influenza viruses from different hosts. Results Phylogenetic analysis revealed that both HA and NA genes have evolved into five distinct clusters, with further analyses indicating that the pandemic 2009 strains have experienced the strongest positive selection. We also found evidence of strong selection acting on the seasonal human H1N1 isolates. However, swine viruses from North America and Eurasia were under weak positive selection, while there was no significant evidence of positive selection acting on the avian isolates. A site-by-site analysis revealed that the positively selected sites were located in both of the cleaved products of HA (HA1 and HA2), as well as NA. In addition, the pandemic 2009 strains were subject to differential selection pressures compared to seasonal human, North American swine and Eurasian swine H1N1 viruses. Conclusions Most of these positively and\\/or differentially selected sites were situated in the B-cell and\\/or T-cell antigenic regions, suggesting that selection at these sites might be responsible for the antigenic variation of the viruses. Moreover, some sites were also associated with glycosylation and receptor-binding ability. Thus, selection at these positions might have helped the pandemic 2009 H1N1 viruses to adapt to the new hosts after they were introduced from pigs to humans. Positive selection on position 274 of NA protein, associated with drug resistance, might account for the prevalence of drug-resistant variants of seasonal human H1N1 influenza viruses, but there was no evidence that positive selection was responsible for the spread of the drug resistance of the pandemic H1N1 strains.

Swine-origin influenza A (H3N2) virus infection in two children--Indiana and Pennsylvania, July-August 2011.

Science.gov (United States)

2011-09-09

Influenza A viruses are endemic in many animal species, including humans, swine, and wild birds, and sporadic cases of transmission of influenza A viruses between humans and animals do occur, including human infections with avian-origin influenza A viruses (i.e., H5N1 and H7N7) and swine-origin influenza A viruses (i.e., H1N1, H1N2, and H3N2). Genetic analysis can distinguish animal origin influenza viruses from the seasonal human influenza viruses that circulate widely and cause annual epidemics. This report describes two cases of febrile respiratory illness caused by swine-origin influenza A (H3N2) viruses identified on August 19 and August 26, 2011, and the current investigations. No epidemiologic link between the two cases has been identified, and although investigations are ongoing, no additional confirmed human infections with this virus have been detected. These viruses are similar to eight other swine-origin influenza A (H3N2) viruses identified from previous human infections over the past 2 years, but are unique in that one of the eight gene segments (matrix [M] gene) is from the 2009 influenza A (H1N1) virus. The acquisition of the M gene in these two swine-origin influenza A (H3N2) viruses indicates that they are "reassortants" because they contain genes of the swine-origin influenza A (H3N2) virus circulating in North American pigs since 1998 and the 2009 influenza A (H1N1) virus that might have been transmitted to pigs from humans during the 2009 H1N1 pandemic. However, reassortments of the 2009 influenza A (H1N1) virus with other swine influenza A viruses have been reported previously in swine. Clinicians who suspect influenza virus infection in humans with recent exposure to swine should obtain a nasopharyngeal swab from the patient for timely diagnosis at a state public health laboratory and consider empiric neuraminidase inhibitor antiviral treatment to quickly limit potential human transmission.

Pneumonia in novel swine-origin influenza A (H1N1) virus infection: High-resolution CT findings

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Li Ping, E-mail: pinglee_2000@yahoo.com [Department of Radiology, The Second Affiliated Hospital of Harbin Medical University, 246 Xue Fu Road, Harbin 150086 (China); Su Dongju, E-mail: hyd_sdj@yahoo.com.cn [Department of Respiratory, The Second Affiliated Hospital of Harbin Medical University, 246 Xue Fu Road, Harbin 150086 (China); Zhang Jifeng, E-mail: zjf2005520@163.com [Department of Radiology, The Second Affiliated Hospital of Harbin Medical University, 246 Xue Fu Road, Harbin 150086 (China); Xia Xudong, E-mail: xiaxd888@163.com [Department of Radiology, The Second Affiliated Hospital of Harbin Medical University, 246 Xue Fu Road, Harbin 150086 (China); Sui Hong, E-mail: suisuihong@126.com [Department of Statistics, Harbin Medical University, 240 Xue Fu Road, Harbin 150086 (China); Zhao Donghui, E-mail: yhwoooooo@yahoo.com.cn [Centers for Disease Control and Prevention of Heilongjiang, 187 Xiang An Street, Harbin 150036 (China)

2011-11-15

Objective: The purpose of our study was to review the initial high-resolution CT (HRCT) findings in pneumonia patients with presumed/laboratory-confirmed novel swine-origin influenza A (H1N1) virus (S-OIV) infection and detect pneumonia earlier. Materials and methods: High-resolution CT (HRCT) findings of 106 patients with presumed/laboratory-confirmed novel S-OIV (H1N1) infection were reviewed. The 106 patients were divided into two groups according to the serious condition of the diseases. The pattern (consolidation, ground-glass, nodules, and reticulation), distribution, and extent of abnormality on the HRCT were evaluated in both groups. The dates of the onset of symptoms of the patients were recorded. Results: The predominant CT findings in the patients at presentation were unilateral or bilateral multifocal asymmetric ground-glass opacities alone (n = 29, 27.4%), with unilateral or bilateral consolidation (n = 50, 47.2%). The consolidation had peribronchovascular and subpleural predominance. The areas of consolidation were found mainly in the posterior, middle and lower regions of the lungs. Reticular opacities were found in 6 cases of the initial MDCT scan. The extent of disease was greater in group 1 patients requiring advanced mechanical ventilation, with diffuse involvement in 19 patients (63.3%) of group 1 patients, and only 15/76 (19.7%) of group 2 patients (p < 0.01, {chi}{sup 2} test). 20 cases (19%) of the 106 patients had small bilateral or unilateral pleural effusions. None had evidence of hilar or mediastinal lymph node enlargement on CT performed at admission or later. Conclusions: The most common radiographic and CT findings in patients with S-OIV infection are unilateral or bilateral ground-glass opacities with or without associated focal or multifocal areas of consolidation. On HRCT, the ground-glass opacities had a predominant peribronchovascular and subpleural distribution. CT plays an important role in the early recognition of severe S

Pneumonia in novel swine-origin influenza A (H1N1) virus infection: High-resolution CT findings

International Nuclear Information System (INIS)

Li Ping; Su Dongju; Zhang Jifeng; Xia Xudong; Sui Hong; Zhao Donghui

2011-01-01

Objective: The purpose of our study was to review the initial high-resolution CT (HRCT) findings in pneumonia patients with presumed/laboratory-confirmed novel swine-origin influenza A (H1N1) virus (S-OIV) infection and detect pneumonia earlier. Materials and methods: High-resolution CT (HRCT) findings of 106 patients with presumed/laboratory-confirmed novel S-OIV (H1N1) infection were reviewed. The 106 patients were divided into two groups according to the serious condition of the diseases. The pattern (consolidation, ground-glass, nodules, and reticulation), distribution, and extent of abnormality on the HRCT were evaluated in both groups. The dates of the onset of symptoms of the patients were recorded. Results: The predominant CT findings in the patients at presentation were unilateral or bilateral multifocal asymmetric ground-glass opacities alone (n = 29, 27.4%), with unilateral or bilateral consolidation (n = 50, 47.2%). The consolidation had peribronchovascular and subpleural predominance. The areas of consolidation were found mainly in the posterior, middle and lower regions of the lungs. Reticular opacities were found in 6 cases of the initial MDCT scan. The extent of disease was greater in group 1 patients requiring advanced mechanical ventilation, with diffuse involvement in 19 patients (63.3%) of group 1 patients, and only 15/76 (19.7%) of group 2 patients (p 2 test). 20 cases (19%) of the 106 patients had small bilateral or unilateral pleural effusions. None had evidence of hilar or mediastinal lymph node enlargement on CT performed at admission or later. Conclusions: The most common radiographic and CT findings in patients with S-OIV infection are unilateral or bilateral ground-glass opacities with or without associated focal or multifocal areas of consolidation. On HRCT, the ground-glass opacities had a predominant peribronchovascular and subpleural distribution. CT plays an important role in the early recognition of severe S-OIV (H1N1).

Underreporting of 2009 H1N1 Influenza Cases

Centers for Disease Control (CDC) Podcasts

2009-12-08

Influenza cases are difficult to track because many people don't go to the doctor or get tested for flu when they're sick. The first months of the 2009 H1N1 influenza pandemic were no different. In this podcast, CDC's Dr. Carrie Reed discusses a study in the December issue of Emerging Infectious Diseases that looked at the actual number of cases reported and estimated the true number of cases when correcting for underreporting.  Created: 12/8/2009 by Emerging Infectious Diseases.   Date Released: 12/8/2009.

EARLY IDENTIFICATION OF SWINE INFLUENZA A (H1N1- BASING ONEPIDEMIOLOGIC CLUE, CLINICAL PRESENTATION, IMAGING FINDINGS, PERIPHERAL LEUCOCYTE COUNTS AND SPO2 LEVELS

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Venkateswararao Kopparti

2017-11-01

Full Text Available BACKGROUND The present study is a retrospective study of 22 cases of RT-PCR positive swine influenza spanning from 2014 to 20-09-2017 with main objective of early identification of influenza A H1N1 basing on epidemiological clue, clinical presentation, imaging findings and lab parameters as early antiviral therapy and judicious management of ARDS brings good outcome as per available literature. 1,2,3 MATERIAL AND METHODS 22 confirmed adult cases of swine influenza by throat/nasopharyngeal swab RT-PCR for H1N1 were studied in terms of clinical presentation, imaging findings, lab manifestations and SpO2 levels4 with particular emphasis on imaging findings. RESULTS 95% presented with symptoms of Influenza-Like Illness (ILI. Nearly, 80% of patients belonged to fourth to fifth decades. Leucocyte count was normal in 75% and 25% had low leucocyte count (<4000, SpO2 levels were normal in 25% and low in 75% cases. CXR was abnormal in 82% of cases of which 83% had mid/lower zone peripheral, patchy, pleural-based consolidations and 17% showed all lung zone opacities. HRCT chest done in 32% of cases showed similar features of chest xray findings with dominant mid/lower zone pleural-based consolidations to ground-glass haziness without pleural effusions and no mediastinal nodal involvement. CONCLUSION As intermittent outbreaks of swine influenza are still continuing in India with recent spurt in incidence in the months of April/May 2017, early diagnosis of H1N1 A is necessary for improved outcome. Early diagnosis is feasible by ILI presentation, normal or low leucocyte count, low SpO2 levels and characteristic radiologic findings of bilateral mid/lower zone pleural-based peripheral patchy opacities to consolidations. As this can be done at peripheral level, primary care physicians need to be sensitised in early diagnosis and treatment and prompt referral to higher centres when needed. Since, the present study is a retrospective one and of public health

A Single-Amino-Acid Substitution at Position 225 in Hemagglutinin Alters the Transmissibility of Eurasian Avian-Like H1N1 Swine Influenza Virus in Guinea Pigs.

Science.gov (United States)

Wang, Zeng; Yang, Huanliang; Chen, Yan; Tao, Shiyu; Liu, Liling; Kong, Huihui; Ma, Shujie; Meng, Fei; Suzuki, Yasuo; Qiao, Chuanling; Chen, Hualan

2017-11-01

Efficient transmission from human to human is the prerequisite for an influenza virus to cause a pandemic; however, the molecular determinants of influenza virus transmission are still largely unknown. In this study, we explored the molecular basis for transmission of Eurasian avian-like H1N1 (EAH1N1) swine influenza viruses by comparing two viruses that are genetically similar but differ in their transmissibility in guinea pigs: the A/swine/Guangxi/18/2011 virus (GX/18) is highly transmissible by respiratory droplet in guinea pigs, whereas the A/swine/Heilongjiang/27/2012 virus (HLJ/27) does not transmit in this animal model. We used reverse genetics to generate a series of reassortants and mutants in the GX/18 background and tested their transmissibility in guinea pigs. We found that a single-amino-acid substitution of glycine (G) for glutamic acid (E) at position 225 (E225G) in the HA1 protein completely abolished the respiratory droplet transmission of GX/18, whereas the substitution of E for G at the same position (G225E) in HA1 enabled HLJ/27 to transmit in guinea pigs. We investigated the underlying mechanism and found that viruses bearing 225E in HA1 replicated more rapidly than viruses bearing 225G due to differences in assembly and budding efficiencies. Our study indicates that the amino acid 225E in HA1 plays a key role in EAH1N1 swine influenza virus transmission and provides important information for evaluating the pandemic potential of field influenza virus strains. IMPORTANCE Efficient transmission among humans is a prerequisite for a novel influenza virus to cause a human pandemic. Transmissibility of influenza viruses is a polygenic trait, and understanding the genetic determinants for transmissibility will provide useful insights for evaluating the pandemic potential of influenza viruses in the field. Several amino acids in the hemagglutinin (HA) protein of influenza viruses have been shown to be important for transmissibility, usually by

Pandemic H1N1 2009 virus in Danish pigs: Diagnosis and lack of surveillance

DEFF Research Database (Denmark)

Larsen, Lars Erik; Nielsen, L. P.; Breum, Solvej Østergaard

In March-April 2009, a novel pandemic H1N1 virus (H1N1v) of likely swine origin emerged in the human population globally. The first case in pigs was reported from Canada in May 2009 and presently almost all countries with pig production have reported cases. The emergence of a new influenza subtype...

Evolution and adaptation of the pandemic A/H1N1 2009 influenza virus

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Ducatez MF

2011-07-01

Full Text Available Mariette F Ducatez, Thomas P Fabrizio, Richard J WebbyDepartment of Infectious Diseases, St Jude Children's Research Hospital, Memphis, TN, USAAbstract: The emergence of the 2009 H1N1 pandemic influenza virus [A(H1N1pdm09] has provided the public health community with many challenges, but also the scientific community with an opportunity to monitor closely its evolution through the processes of drift and shift. To date, and despite having circulated in humans for nearly two years, little antigenic variation has been observed in the A(H1N1pdm09 viruses. However, as the A(H1N1pdm09 virus continues to circulate and the immunologic pressure within the human population increases, future antigenic change is almost a certainty. Several coinfections of A(H1N1pdm09 and seasonal A(H1N1 or A(H3N2 viruses have been observed, but no reassortant viruses have been described in humans, suggesting a lack of fitness of reassortant viruses or a lack of opportunities for interaction of different viral lineages. In contrast, multiple reassortment events have been detected in swine populations between A(H1N1 pdm09 and other endemic swine viruses. Somewhat surprisingly, many of the well characterized influenza virus virulence markers appear to have limited impact on the phenotype of the A(H1N1pdm09 viruses when they have been introduced into mutant viruses in laboratory settings. As such, it is unclear what the evolutionary path of the pandemic virus will be, but the monitoring of any changes in the circulating viruses will remain a global public and animal health priority.Keywords: influenza, pandemic, evolution, adaptation

Mongrelised genetics of H1N1 virus: A bird′s eyeview

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Nagarathna C

2010-01-01

Full Text Available H1N1 influenza, also known as "novel H1N1 virus" has led to a "global outcry." This virus is more virulent when compared with other seasonal flu viruses. Virulence may change as the adaptive mutation gene increases within the virus. A study at the US Centre for Disease Control and Prevention published in May 2009 found that children had no preexisting immunity to the new strain as they showed no cross-reactive antibody reaction when compared with adults aged 18-64 years, who showed a cross-reactive antibody reaction of 6-9% and older adults with 33% immunity. This review article depicts H1N1 virus, its virulence with genetic evolution potential and preventive protocol for the dental professionals. This would allow us to comprehend the changes in the disease process and contribute in its prevention as "prevention is better than cure."

Dual Infection of Novel Influenza Viruses A/H1N1 and A/H3N2 in a Cluster of Cambodian Patients

Science.gov (United States)

2011-01-01

influenza viruses as well as the avian influenza virus A/H5N1...on full genome sequencing. This incident confirms dual influenza virus infections and highlights the risk of zoonotic and seasonal influenza viruses ...North American swine influenza viruses , North American avian influenza viruses , human influenza viruses , and a Eurasian swine influenza virus . 18

Finding a new drug and vaccine for emerging swine flu: What is the concept?

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Viroj Wiwanitkit

2009-08-01

Full Text Available Viroj WiwanitkitWiwanitkit House, Bangkhae, Bangkok 10160Abstract: Influenza is a well known infection of the respiratory system. The main clinical manifestations of influenza include fever, sore throat, headache, cough, coryza, and malaise. Apart from the well known classical influenza, there are also groups of influenza virus infections that are called “atypical infection”. These infections are usually due to a novel influenza virus infection. In early 2009, an emerging novel influenza originating from Mexico called swine flu was reported. The World Health Organization noted a level VI precaution, the highest level precaution possible, for this newest influenza virus infection. As of June 2009, it is not known if this disease will be successfully controlled. Finding new drugs and vaccine for the emerging swine flu is still required to cope with this emerging worldwide problem.Keywords: swine flu, drug, vaccine, concept

Why do I need it? I am not at risk! Public perceptions towards the pandemic (H1N1 2009 vaccine

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Ward Kirsten F

2010-04-01

Full Text Available Abstract Background On the 30th September 2009, the pandemic (H1N1 2009 influenza vaccine was made available to adults and children aged 10 years and over, in Australia. Acceptance of a novel vaccine is influenced by perceptions of risk including risk of infection, risk of death or severe illness and risk of serious vaccine side-effects. We surveyed a sample of residents from Sydney, Australia to ascertain their risk perception, attitudes towards the pandemic and willingness to accept the pandemic (H1N1 2009 influenza vaccine. Methods We sampled residents using a cross-sectional intercept design during the WHO Phase 6. Members of the public were approached in shopping and pedestrian malls to undertake the survey during September and October 2009. The survey measured perceived risk, seriousness of disease, recent behavioural changes, likely acceptance of the pandemic (H1N1 2009 vaccine and issues relating to uptake and perceived safety. Results Of the 627 respondents, the majority felt that they had a "very low to low" (332/627, 52.9% risk of acquiring H1N1. 24.5% (154/627 of respondents believed that the disease would "very seriously or extremely" affect their health. Nearly half (305/627, 48.6% reported that in response to the "swine flu" outbreak they had undertaken one or more of the investigated behavioural changes. Overall, the self-reported likelihood of accepting vaccination against novel H1N1 was 54.7% (343/627. Conclusions While, most participants did not believe they were at high risk of acquiring pandemic H1N1 2009, over half of the sample indicated that they would accept the vaccine. Participants who were vaccinated against the seasonal influenza were more likely to receive the H1N1 vaccine. Concerns about safety, the possibility of side effects and the vaccine development process need to be addressed.

Genetic Reassortment Among the Influenza Viruses (Avian Influenza, Human Influenza and Swine Influenza in Pigs

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Dyah Ayu Hewajuli

2012-12-01

Full Text Available Influenza A virus is a hazardous virus and harm to respiratory tract. The virus infect birds, pigs, horses, dogs, mammals and humans. Pigs are important hosts in ecology of the influenza virus because they have two receptors, namely NeuAc 2,3Gal and NeuAc 2,6Gal which make the pigs are sensitive to infection of influenza virus from birds and humans and genetic reassortment can be occurred. Classical swine influenza H1N1 viruses had been circulated in pigs in North America and other countries for 80 years. In 1998, triple reassortant H3N2 swine influenza viruses that contains genes of human influenza A virus (H3N2, swine influenza virus (H1N1 and avian influenza are reported as cause an outbreaks in pigs in North America. Furthermore, the circulation of triple reassortant H3N2 swine influenza virus resulting reassortant H1N1 swine influenza and reassortant H1N2 swine influenza viruses cause infection in humans. Humans who were infected by triple reassortant swine influenza A virus (H1N1 usually made direct contact with pigs. Although without any clinical symptoms, pigs that are infected by triple reassortant swine influenza A (H1N1 can transmit infection to the humans around them. In June 2009, WHO declared that pandemic influenza of reassortant H1N1 influenza A virus (novel H1N1 has reached phase 6. In Indonesia until 2009, there were 1005 people were infected by H1N1 influenza A and 5 of them died. Novel H1N1 and H5N1 viruses have been circulated in humans and pigs in Indonesia. H5N1 reassortant and H1N1 viruses or the seasonal flu may could arise because of genetic reassortment between avian influenza and humans influenza viruses that infect pigs together.

PA-X protein contributes to virulence of triple-reassortant H1N2 influenza virus by suppressing early immune responses in swine.

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Xu, Guanlong; Zhang, Xuxiao; Liu, Qinfang; Bing, Guoxia; Hu, Zhe; Sun, Honglei; Xiong, Xin; Jiang, Ming; He, Qiming; Wang, Yu; Pu, Juan; Guo, Xin; Yang, Hanchun; Liu, Jinhua; Sun, Yipeng

2017-08-01

Previous studies have identified a functional role of PA-X for influenza viruses in mice and avian species; however, its role in swine remains unknown. Toward this, we constructed PA-X deficient virus (Sw-FS) in the background of a Triple-reassortment (TR) H1N2 swine influenza virus (SIV) to assess the impact of PA-X in viral virulence in pigs. Expression of PA-X in TR H1N2 SIV enhanced viral replication and host protein synthesis shutoff, and inhibited the mRNA levels of type I IFNs and proinflammatory cytokines in porcine cells. A delay of proinflammatory responses was observed in lungs of pigs infected by wild type SIV (Sw-WT) compared to Sw-FS. Furthermore, Sw-WT virus replicated and transmitted more efficiently than Sw-FS in pigs. These results highlight the importance of PA-X in the moderation of virulence and immune responses of TR SIV in swine, which indicated that PA-X is a pro-virulence factor in TR SIV in pigs. Copyright © 2017 Elsevier Inc. All rights reserved.

Ethnic differences in susceptibilities to A(H1N1) flu: An epidemic ...

African Journals Online (AJOL)

STORAGESEVER

2009-12-29

Dec 29, 2009 ... ... Center, the Second Affiliated Hospital of Soochow University, Suzhou 215004, Jiangsu, .... countries including Mexico, the country of the A (H1N1) outbreak origin. The ... precious resources used more effectively for specific.

Clinical and epidemiologic characteristics of an outbreak of novel H1N1 (swine origin) influenza A virus among United States military beneficiaries.

Science.gov (United States)

Crum-Cianflone, Nancy F; Blair, Patrick J; Faix, Dennis; Arnold, John; Echols, Sara; Sherman, Sterling S; Tueller, John E; Warkentien, Tyler; Sanguineti, Gabriela; Bavaro, Mary; Hale, Braden R

2009-12-15

A novel swine-origin influenza A (H1N1) virus was identified in March 2009 and subsequently caused worldwide outbreaks. The San Diego region was an early focal point of the emerging pandemic. We describe the clinical and epidemiologic characteristics of this novel strain in a military population to assist in future outbreak prevention and control efforts. We performed an epidemiologic evaluation of novel H1N1 virus infections diagnosed in San Diego County among 96,258 local US military beneficiaries. The structured military medical system afforded the ability to obtain precise epidemiologic information on the impact on H1N1 virus infection in a population. The novel H1N1 virus was confirmed using real-time reverse transcriptase polymerase chain reaction (rRT-PCR). From 21 April through 8 May 2009, 761 patients presented with influenza-like illness and underwent rRT-PCR testing. Of these patients, 97 had confirmed novel H1N1 virus infection, with an incidence rate of 101 cases per 100,000 persons. The median age of H1N1 patients with H1N1 virus infection was 21 years (interquartile range, 15-25 years). Fever was a universal symptom in patients with H1N1 virus infection; other symptoms included cough (present in 96% of patients), myalgia or arthralgia (57%), and sore throat (51%). Sixty-eight (70%) of our patients had an identifiable epidemiologic link to another confirmed patient. The largest cluster of cases of H1N1 virus infection occurred on a Navy ship and involved 32 (8%) of 402 crew members; the secondary attack rate was 6%-14%. The rapid influenza testing that was used during this outbreak had a sensitivity of 51% and specificity of 98%, compared with rRT-PCR. Only 1 patient was hospitalized, and there were no deaths. A novel H1N1 influenza A virus caused a significant outbreak among military beneficiaries in San Diego County, including a significant cluster of cases onboard a Navy ship. The outbreak described here primarily affected adolescents and young

Seroprevalence of three influenza A viruses (H1N1, H3N2, and H3N8) in pet dogs presented to a veterinary hospital in Ohio.

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Jang, Hyesun; Jackson, Yasmine K; Daniels, Joshua B; Ali, Ahmed; Kang, Kyung-Il; Elaish, Mohamed; Lee, Chang-Won

2017-08-31

The prevalence of canine H3N8 influenza and human H1N1 and H3N2 influenza in dogs in Ohio was estimated by conducting serologic tests on 1,082 canine serum samples. In addition, risk factors, such as health status and age were examined. The prevalences of human H1N1, H3N2, and canine H3N8 influenzas were 4.0%, 2.4%, and 2.3%, respectively. Two samples were seropositive for two subtypes (H1N1 and H3N2; H1N1 and canine influenza virus [CIV] H3N8). Compared to healthy dogs, dogs with respiratory signs were 5.795 times more likely to be seropositive against H1N1 virus ( p = 0.042). The prevalence of human flu infection increased with dog age and varied by serum collection month. The commercial enzyme-linked immunosorbent assay used in this study did not detect nucleoprotein-specific antibodies from many hemagglutination inhibition positive sera, which indicates a need for the development and validation of rapid tests for influenza screening in canine populations. In summary, we observed low exposure of dogs to CIV and human influenza viruses in Ohio but identified potential risk factors for consideration in future investigations. Our findings support the need for establishment of reliable diagnostic standards for serologic detection of influenza infection in canine species.

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

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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.

Coinfection with influenza A(H1N1pdm09 and dengue virus in fatal cases

Directory of Open Access Journals (Sweden)

Anne Carolinne Bezerra Perdigão

2016-01-01

Full Text Available Abstract We report on four patients with fatal influenza A(H1N1pdm09 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(H1N1pdm09 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(H1N1pdm09 with DENV, which occurred during the dengue and influenza season in 2012 and 2013 in Ceará.

Surfing the web during pandemic flu: availability of World Health Organization recommendations on prevention.

Science.gov (United States)

Gesualdo, Francesco; Romano, Mariateresa; Pandolfi, Elisabetta; Rizzo, Caterina; Ravà, Lucilla; Lucente, Daniela; Tozzi, Alberto E

2010-09-20

People often search for information on influenza A(H1N1)v prevention on the web. The extent to which information found on the Internet is consistent with recommendations issued by the World Health Organization is unknown. We conducted a search for "swine flu" accessing 3 of the most popular search engines through different proxy servers located in 4 English-speaking countries (Australia, Canada, UK, USA). We explored each site resulting from the searches, up to 4 clicks starting from the search engine page, analyzing availability of World Health Organization recommendations for swine flu prevention. Information on hand cleaning was reported on 79% of the 147 websites analyzed; staying home when sick was reported on 77.5% of the websites; disposing tissues after sneezing on 75.5% of the websites. Availability of other recommendations was lower. The probability of finding preventative recommendations consistent with World Health Organization varied by country, type of website, and search engine. Despite media coverage on H1N1 influenza, relevant information for prevention is not easily found on the web. Strategies to improve information delivery to the general public through this channel should be improved.

PB1-F2 Protein Does Not Impact the Virulence of Triple-Reassortant H3N2 Swine Influenza Virus in Pigs but Alters Pathogenicity and Transmission in Turkeys.

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Deventhiran, Jagadeeswaran; Kumar, Sandeep R P; Raghunath, Shobana; Leroith, Tanya; Elankumaran, Subbiah

2016-01-01

PB1-F2 protein, the 11th influenza A virus (IAV) protein, is considered to play an important role in primary influenza virus infection and postinfluenza secondary bacterial pneumonia in mice. The functional role of PB1-F2 has been reported to be a strain-specific and host-specific phenomenon. Its precise contribution to the pathogenicity and transmission of influenza virus in mammalian host, such as swine, and avian hosts, such as turkeys, remain largely unknown. In this study, we explored the role of PB1-F2 protein of triple-reassortant (TR) H3N2 swine influenza virus (SIV) in pigs and turkeys. Using the eight-plasmid reverse genetics system, we rescued wild-type SIV A/swine/Minnesota/1145/2007 (H3N2) (SIV 1145-WT), a PB1-F2 knockout mutant (SIV 1145-KO), and its N66S variant (SIV 1145-N66S). The ablation of PB1-F2 in SIV 1145 modulated early-stage apoptosis but did not affect the viral replication in swine alveolar macrophage cells. In pigs, PB1-F2 expression did not affect nasal shedding, lung viral load, immunophenotypes, and lung pathology. On the other hand, in turkeys, SIV 1145-KO infected poults, and its in-contacts developed clinical signs earlier than SIV 1145-WT groups and also displayed more extensive histopathological changes in intestine. Further, turkeys infected with SIV 1145-N66S displayed poor infectivity and transmissibility. The more extensive histopathologic changes in intestine and relative transmission advantage observed in turkeys infected with SIV 1145-KO need to be further explored. Taken together, these results emphasize the host-specific roles of PB1-F2 in the pathogenicity and transmission of IAV. Novel triple-reassortant H3N2 swine influenza virus emerged in 1998 and spread rapidly among the North American swine population. Subsequently, it showed an increased propensity to reassort, generating a range of reassortants. Unlike classical swine influenza virus, TR SIV produces a full-length PB1-F2 protein, which is considered an important

When pictures waste a thousand words: analysis of the 2009 H1N1 pandemic on television news.

Science.gov (United States)

Luth, Westerly; Jardine, Cindy; Bubela, Tania

2013-01-01

Effective communication by public health agencies during a pandemic promotes the adoption of recommended health behaviours. However, more information is not always the solution. Rather, attention must be paid to how information is communicated. Our study examines the television news, which combines video and audio content. We analyse (1) the content of television news about the H1N1 pandemic and vaccination campaign in Alberta, Canada; (2) the extent to which television news content conveyed key public health agency messages; (3) the extent of discrepancies in audio versus visual content. We searched for "swine flu" and "H1N1" in local English news broadcasts from the CTV online video archive. We coded the audio and visual content of 47 news clips during the peak period of coverage from April to November 2009 and identified discrepancies between audio and visual content. The dominant themes on CTV news were the vaccination rollout, vaccine shortages, long line-ups (queues) at vaccination clinics and defensive responses by public health officials. There were discrepancies in the priority groups identified by the provincial health agency (Alberta Health and Wellness) and television news coverage as well as discrepancies between audio and visual content of news clips. Public health officials were presented in official settings rather than as public health practitioners. The news footage did not match the main public health messages about risk levels and priority groups. Public health agencies lost control of their message as the media focused on failures in the rollout of the vaccination campaign. Spokespeople can enhance their local credibility by emphasizing their role as public health practitioners. Public health agencies need to learn from the H1N1 pandemic so that future television communications do not add to public confusion, demonstrate bureaucratic ineffectiveness and contribute to low vaccination rates.

Triple-reassortant swine influenza A (H1) in humans in the United States, 2005-2009.

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Shinde, Vivek; Bridges, Carolyn B; Uyeki, Timothy M; Shu, Bo; Balish, Amanda; Xu, Xiyan; Lindstrom, Stephen; Gubareva, Larisa V; Deyde, Varough; Garten, Rebecca J; Harris, Meghan; Gerber, Susan; Vagasky, Susan; Smith, Forrest; Pascoe, Neal; Martin, Karen; Dufficy, Deborah; Ritger, Kathy; Conover, Craig; Quinlisk, Patricia; Klimov, Alexander; Bresee, Joseph S; Finelli, Lyn

2009-06-18

Triple-reassortant swine influenza A (H1) viruses--containing genes from avian, human, and swine influenza viruses--emerged and became enzootic among pig herds in North America during the late 1990s. We report the clinical features of the first 11 sporadic cases of infection of humans with triple-reassortant swine influenza A (H1) viruses reported to the Centers for Disease Control and Prevention, occurring from December 2005 through February 2009, until just before the current epidemic of swine-origin influenza A (H1N1) among humans. These data were obtained from routine national influenza surveillance reports and from joint case investigations by public and animal health agencies. The median age of the 11 patients was 10 years (range, 16 months to 48 years), and 4 had underlying health conditions. Nine of the patients had had exposure to pigs, five through direct contact and four through visits to a location where pigs were present but without contact. In another patient, human-to-human transmission was suspected. The range of the incubation period, from the last known exposure to the onset of symptoms, was 3 to 9 days. Among the 10 patients with known clinical symptoms, symptoms included fever (in 90%), cough (in 100%), headache (in 60%), and diarrhea (in 30%). Complete blood counts were available for four patients, revealing leukopenia in two, lymphopenia in one, and thrombocytopenia in another. Four patients were hospitalized, two of whom underwent invasive mechanical ventilation. Four patients received oseltamivir, and all 11 recovered from their illness. From December 2005 until just before the current human epidemic of swine-origin influenza viruses, there was sporadic infection with triple-reassortant swine influenza A (H1) viruses in persons with exposure to pigs in the United States. Although all the patients recovered, severe illness of the lower respiratory tract and unusual influenza signs such as diarrhea were observed in some patients, including

The swine flu vaccine, public attitudes, and researcher interpretations: a systematic review of qualitative research.

Science.gov (United States)

Carlsen, Benedicte; Glenton, Claire

2016-06-24

During pandemics, health authorities may be uncertain about the spread and severity of the disease and the effectiveness and safety of available interventions. This was the case during the swine flu (H1N1) pandemic of 2009-2010, and governments were forced to make decisions despite these uncertainties. While many countries chose to implement wide scale vaccination programmes, few accomplished their vaccination goals. Many research studies aiming to explore barriers and facilitators to vaccine uptake have been conducted in the aftermath of the pandemic, including several qualitative studies. 1. To explore public attitudes to the swine flu vaccine in different countries through a review of qualitative primary studies. 2. To describe and discuss the implications drawn by the primary study authors. Systematic review of qualitative research studies, using a broadly comparative cross case-study approach. Study quality was appraised using an adaptation of the Critical Appraisal Skills Programme (CASP) quality assessment tool. The review indicates that the public had varying opinions about disease risk and prevalence and had concerns about vaccine safety. Most primary study authors concluded that participants were uninformed, and that more information about the disease and the vaccine would have led to an increase in vaccine uptake. We find these conclusions problematic. We suggest instead that people's questions and concerns were legitimate given the uncertainties of the situation at the time and the fact that the authorities did not have the necessary information to convince the public. Our quality assessment of the included studies points to a lack of reflexivity and a lack of information about study context. We suggest that these study weaknesses are tied to primary study authors' lack of acknowledgement of the uncertainties surrounding the disease and the vaccine. While primary study authors suggest that authorities could increase vaccine uptake through increased

Key Facts about Influenza (Flu) and Flu Vaccine

Science.gov (United States)

... Swine Variant Pandemic Other Key Facts About Influenza (Flu) Language: English (US) Español Recommend on Facebook Tweet ... Flu Treating Flu What is Influenza (also called Flu)? The flu is a contagious respiratory illness caused ...

EFSA Panel Animal Health and Welfare (AHAW); Scientific Opinion on the pandemic (H1N1) 2009 influenza and its potential implications for animal health

DEFF Research Database (Denmark)

Bøtner, Anette; Brown, Ian; Capua, Ilaria

. Occasionally, pigs have been infected following exposure to pH1N1 infected humans. In pigs, a subclinical course was common and when clinical signs were seen (coughing, fever) they were generally mild. Presently, the clinical impact of pH1N1virus on the EU pig population is considered minimal. In poultry....... Such vaccines efficiently prevent disease by reducing virus replication in the lungs. However, voluntary vaccination of swine with these vaccines has not halted the circulation of SIV in swine. There is no urgency for vaccination of pigs against pH1N1 virus. Currently, no vaccines against H1 viruses for poultry...... are available but at present, there is no need to vaccinate poultry against pH1N1 virus. Monitoring of circulating influenza viruses in swine and poultry populations should be instigated to monitor the evolution of the pH1N1 virus including changes in virulence....

A Historical Perspective of Influenza A(H1N2) Virus

OpenAIRE

Komadina, Naomi; McVernon, Jodie; Hall, Robert; Leder, Karin

2014-01-01

The emergence and transition to pandemic status of the influenza A(H1N1)A(H1N1)pdm09) virus in 2009 illustrated the potential for previously circulating human viruses to re-emerge in humans and cause a pandemic after decades of circulating among animals. Within a short time of the initial emergence of A(H1N1)pdm09 virus, novel reassortants were isolated from swine. In late 2011, a variant (v) H3N2 subtype was isolated from humans, and by 2012, the number of persons infected began to increase ...

Chalcones as novel influenza A (H1N1) neuraminidase inhibitors from Glycyrrhiza inflata

DEFF Research Database (Denmark)

Dao, Trong Tuan; Nguyen, Phi Hung; Lee, Hong Sik

2011-01-01

The emergence of highly pathogenic influenza A virus strains, such as the new H1N1 swine influenza (novel influenza), represents a serious threat to global human health. During our course of an anti-influenza screening program on natural products, one new licochalcone G (1) and seven known (2-8) ...

Pathogenesis of swine influenza virus (Thai isolates in weanling pigs: an experimental trial

Directory of Open Access Journals (Sweden)

Kitikoon Pravina

2009-03-01

Full Text Available Abstract Background The objective of this study is to investigate the pathogenesis of swine influenza virus (SIV subtype H1N1 and H3N2 (Thai isolates in 22-day-old SPF pigs. Results The study found that all pigs in the infected groups developed typical signs of flu-like symptoms on 1–4 days post- infection (dpi. The H1N1-infected pigs had greater lung lesion scores than those of the H3N2-infected pigs. Histopathological lesions related to swine influenza-induced lesions consisting of epithelial cells damage, airway plugging and peribronchial and perivascular mononuclear cell infiltration were present in both infected groups. Immunofluorescence and immunohistochemistry using nucleoprotein specific monoclonal antibodies revealed positive staining cells in lung sections of both infected groups at 2 and 4 dpi. Virus shedding was detected at 2 dpi from both infected groups as demonstrated by RT-PCR and virus isolation. Conclusion The results demonstrated that both SIV subtypes were able to induce flu-like symptoms and lung lesions in weanling pigs. However the severity of the diseases with regards to lung lesions both gross and microscopic lesions was greater in the H1N1-infected pigs. Based on phylogenetic analysis, haemagglutinin gene of subtype H1N1 from Thailand clustered with the classical H1 SIV sequences and neuraminidase gene clustered with virus of avian origin, whereas, both genes of H3N2 subtype clustered with H3N2 human-like SIV from the 1970s.

Impact of information on intentions to vaccinate in a potential epidemic: Swine-origin Influenza A (H1N1).

Science.gov (United States)

Chanel, Olivier; Luchini, Stéphane; Massoni, Sébastien; Vergnaud, Jean-Christophe

2011-01-01

Vaccination campaigns to prevent the spread of epidemics are successful only if the targeted populations subscribe to the recommendations of health authorities. However, because compulsory vaccination is hardly conceivable in modern democracies, governments need to convince their populations through efficient and persuasive information campaigns. In the context of the swine-origin A (H1N1) 2009 pandemic, we use an interactive study among the general public in the South of France, with 175 participants, to explore what type of information can induce change in vaccination intentions at both aggregate and individual levels. We find that individual attitudes to vaccination are based on rational appraisal of the situation, and that it is information of a purely scientific nature that has the only significant positive effect on intention to vaccinate. Copyright © 2010 Elsevier Ltd. All rights reserved.