scholarly journals Molecular characterization of influenza A(H1N1)pdm09 virus circulating during the 2009 outbreak in Thua Thien Hue, Vietnam

2013 ◽  
Vol 7 (03) ◽  
pp. 235-242 ◽  
Author(s):  
Le Van An ◽  
Le Thi Bao Chi ◽  
Nguyen Hoang Bach ◽  
Huynh Thi Hai Duong ◽  
Massimo Deligios ◽  
...  
Keyword(s):  
Amino Acid ◽  
Influenza A ◽  
The United States ◽  
Rt Pcr ◽  
Viral Isolation ◽  
Pdm09 Virus ◽  
Influenza A H1n1 ◽  
Virus Culture ◽  
Na Sequences ◽  
Viral Diagnosis

Introduction: The influenza A(H1N1)pdm09 virus arrived in Vietnam in May 2009 via the United States and rapidly spread throughout the country. This study provides data on the viral diagnosis and molecular epidemiology of influenza A(H1N1)pdm09 virus isolated in Thua Thien Hue Province, central Vietnam. Methodology: Nasopharyngeal swabs and throat swabs from 53 clinically infected patients in the peak of the outbreak were processed for viral diagnosis by culture and RT-PCR. Sequencing of entire HA and NA genes of representative isolates and molecular epidemiological analysis were performed. Results: A total of 32 patients were positive for influenza A virus by virus culture and/or RT-PCR; of these 22 were positive both by viral isolation and RT-PCR, 2 only by virus culture and 8 only by RT-PCR. The novel subtype of influenza A(H1N1)pdm09 was present in 93.4% of the isolates. Phylogenetic analysis of the HA and NA gene sequences showed identities higher than 99.50% in both genes. They were also similar to reference isolates in HA sequences (> 99% identity) and in NA sequences (>98.50% identity). Amino acid sequences predicted for the HA gene were highly identical to reference strains. The NA amino acid substitutions identified did not include the oseltamivir-resistant H275Y substitution. Conclusion: viral isolation and RT-PCR together were useful for diagnosis of the influenza A(H1N1)pdm09 virus. Variations in HA and NA sequences are similar to those identified in worldwide reference isolates and no drug resistance was found.

Characteristic amino acid changes of influenza A(H1N1)pdm09 virus PA protein enhance A(H7N9) viral polymerase activity

Virus Genes ◽  
2016 ◽  
Vol 52 (3) ◽  
pp. 346-353 ◽  
Author(s):  
Jun Liu ◽  
Feng Huang ◽  
Junsong Zhang ◽  
Likai Tan ◽  
Gen Lu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Influenza A ◽  
Polymerase Activity ◽  
Viral Polymerase ◽  
Pdm09 Virus ◽  
Influenza A H1n1

scholarly journals 2553. Individual Patient-Level Data Meta-Analysis of Live Attenuated and Inactivated Influenza Vaccine Effectiveness Among US Children, 2013–2014 Through 2015–2016

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S68-S68
Author(s):  
Jessie Chung ◽  
Brendan Flannery ◽  
Rodolfo Begue ◽  
Herve Caspard ◽  
Laurie Demarcus ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
Influenza A ◽  
The United States ◽  
Vaccine Effectiveness ◽  
Vaccination Status ◽  
Influenza B ◽  
Rt Pcr ◽  
Current Season ◽  
Influenza A H1n1 ◽  
Vaccine Type

Abstract Background Quadrivalent live attenuated influenza vaccine (LAIV4) was not recommended for use in the United States for the 2016–2017 and 2017–2018 influenza seasons based on US observational studies of vaccine effectiveness (VE) from 2013–2014 to 2015–2016. We pooled individual patient data on children aged 2–17 years enrolled in 5 US studies during these 3 influenza seasons to further investigate VE by vaccine type. Methods Analyses included 17,173 children enrolled in the US Department of Defense Global Laboratory-based Influenza Surveillance Program, US Influenza Vaccine Effectiveness Network, Influenza Incidence Surveillance Project, Influenza Clinical Investigation for Children, and a Louisiana State University study. Participants’ specimens were tested for influenza by reverse transcription-polymerase chain reaction (RT-PCR), culture, or a combination of rapid antigen testing and RT-PCR. VE was calculated by comparing odds of vaccination with either inactivated influenza vaccine (IIV) or LAIV4 among influenza-positive cases to test-negative controls and calculated as 100 × (1 − odds ratio) in logistic regression models with age, calendar time, influenza season, and study site (random effect). Patients were stratified by prior season vaccination status in a subanalysis. Results Overall, 38% of patients (N = 6,558) were vaccinated in the current season, of whom 30% (N = 1,979) received LAIV4. Pooled VE of IIV against any influenza virus was 51% (95% CI: 47, 54) versus 26% (95% CI: 15, 36) for LAIV4. Point estimates for pooled VE against any influenza by age group ranged from 45% to 58% for IIV and 19% to 34% for LAIV4 during the 3 seasons (Figures 1 and 2). Pooled VE against influenza A(H1N1)pdm09 was 67% (95% CI: 62, 72) for IIV versus 20% (95% CI: −6, 39) for LAIV4. Pooled VE against influenza A(H3N2) was 29% (95% CI: 14, 42) for IIV versus 7% (95% CI: −11, 23) for LAIV4, and VE against influenza B was 52% (95% CI: 42, 60) for IIV and 66% (95% CI: 47, 77) for LAIV4. VE against influenza A(H1N1)pdm09 was lower for LAIV4 versus IIV across all strata of prior season vaccination (Figure 3). Conclusion Consistent with individual studies, our pooled analyses found that LAIV4 effectiveness was reduced for all age groups against influenza A(H1N1)pdm09 compared with IIV. This result did not vary based on prior vaccination status. Disclosures H. Caspard, AstraZeneca: Employee, Salary.

Rapid detection of the S247N neuraminidase mutation in influenza A(H1N1)pdm09 virus by one-step duplex RT-PCR assay

2013 ◽  
Vol 188 (1-2) ◽  
pp. 73-75 ◽  
Author(s):  
Ikuyo Takayama ◽  
Mina Nakauchi ◽  
Seiichiro Fujisaki ◽  
Takato Odagiri ◽  
Masato Tashiro ◽  
...  
Keyword(s):  
Rapid Detection ◽  
Influenza A ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Pdm09 Virus ◽  
Influenza A H1n1 ◽  
One Step

Pleiotropic effects of hemagglutinin amino acid substitutions of influenza A(H1N1)pdm09 virus escape mutants

2018 ◽  
Vol 251 ◽  
pp. 91-97 ◽  
Author(s):  
Irina A. Rudneva ◽  
Tatiana A. Timofeeva ◽  
Evgenia A. Mukasheva ◽  
Anna V. Ignatieva ◽  
Aleksandr A. Shilov ◽  
...  
Keyword(s):  
Amino Acid ◽  
Influenza A ◽  
Pleiotropic Effects ◽  
Amino Acid Substitutions ◽  
Virus Escape ◽  
Pdm09 Virus ◽  
Influenza A H1n1 ◽  
Escape Mutants

scholarly journals Amino acid substitution D222N from fatal influenza infection affects receptor-binding properties of the influenza A(H1N1)pdm09 virus

Virology ◽  
2015 ◽  
Vol 484 ◽  
pp. 15-21 ◽  
Author(s):  
Adriana Matos-Patrón ◽  
Lauren Byrd-Leotis ◽  
David A. Steinhauer ◽  
Wendy S. Barclay ◽  
Guadalupe Ayora-Talavera
Keyword(s):  
Amino Acid ◽  
Receptor Binding ◽  
Amino Acid Substitution ◽  
Influenza A ◽  
Influenza Infection ◽  
Binding Properties ◽  
Pdm09 Virus ◽  
Influenza A H1n1

scholarly journals IgM, IgG, and IgA Antibody Responses to Influenza A(H1N1)pdm09 Hemagglutinin in Infected Persons during the First Wave of the 2009 Pandemic in the United States

2014 ◽  
Vol 21 (8) ◽  
pp. 1054-1060 ◽  
Author(s):  
Zhu-Nan Li ◽  
Seh-Ching Lin ◽  
Paul J. Carney ◽  
Ji Li ◽  
Feng Liu ◽  
...  
Keyword(s):  
Virus Infection ◽  
Influenza A ◽  
Age Groups ◽  
The United States ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Lower Sensitivity ◽  
Pdm09 Virus ◽  
Influenza A H1n1 ◽  
Iga Antibody

ABSTRACTThe novel influenza A(H1N1)pdm09 virus caused an influenza pandemic in 2009. IgM, IgG, and IgA antibody responses to A(H1N1)pdm09 hemagglutinin (HA) following A(H1N1)pdm09 virus infection were analyzed to understand antibody isotype responses. Age-matched control sera collected from U.S. residents in 2007 and 2008 were used to establish baseline levels of cross-reactive antibodies. IgM responses often used as indicators of primary virus infection were mainly detected in young patient groups (≤5 years and 6 to 15 years old), not in older age groups, despite the genetic and antigenic differences between the HA of A(H1N1)pdm09 virus and pre-2009 seasonal H1N1 viruses. IgG and IgA responses to A(H1N1)pdm09 HA were detected in all age groups of infected persons. In persons 17 to 80 years old, paired acute- and convalescent-phase serum samples demonstrated ≥4-fold increases in the IgG and IgA responses to A(H1N1)pdm09 HA in 80% and 67% of A(H1N1)pdm09 virus-infected persons, respectively. The IgG antibody response to A(H1N1)pdm09 HA was cross-reactive with HAs from H1, H3, H5, and H13 subtypes, suggesting that infections with subtypes other than A(H1N1)pdm09 might result in false positives by enzyme-linked immunosorbent assay (ELISA). Lower sensitivity compared to hemagglutination inhibition and microneutralization assays and the detection of cross-reactive antibodies against homologous and heterologous subtype are major drawbacks for the application of ELISA in influenza serologic studies.

scholarly journals Epidemiological analysis of the influenza A(H1N1)v outbreak in Bolivia, May-August 2009

2009 ◽  
Vol 14 (35) ◽  
Author(s):  
A Gianella ◽  
A Walter ◽  
R Revollo ◽  
R Loayza ◽  
J Vargas ◽  
...  
Keyword(s):  
Preliminary Analysis ◽  
Influenza A ◽  
The United States ◽  
Nasal Discharge ◽  
Age Group ◽  
Rt Pcr ◽  
Epidemiological Analysis ◽  
Influenza A H1n1 ◽  
Imported Cases ◽  
Pandemic Influenza H1n1

The outbreak of pandemic influenza (H1N1) began in Bolivia on 25 May 2009. Between May and August, the National Center of Tropical Disease (CENETROP) analysed by RT-PCR 7,060 samples of which 12.7% were positive. A preliminary analysis of the 895 confirmed cases identified between May and August 2009 describes epidemiological and clinical characteristics. After the first imported cases from the United States and Peru, the locally acquired infections predominated (90%). The number of cases was highest in the age group of 10 to 29 year-olds, and 89.6% of cases were observed in people under the age of 40 years. Fever, cough, nasal discharge and headache remained the main symptoms.

scholarly journals Features of Epidemic Process of Influenza and its Etiology in the Countries of the Northern and Southern Hemispheres in the Period of Circulation of Pandemic Virus A(H1N1)pdm09 (According to WHO)

2020 ◽  
Vol 18 (6) ◽  
pp. 15-25
Author(s):  
L. S. Karpova ◽  
M. Yu. Pelikh ◽  
N. M. Popovtseva ◽  
T. P Stolyarova ◽  
K. M. Volik
Keyword(s):  
Influenza A ◽  
The United States ◽  
Influenza Viruses ◽  
Antigenic Structure ◽  
Influenza B ◽  
Tropical Countries ◽  
Antigenic Variability ◽  
Pdm09 Virus ◽  
Influenza A H1n1 ◽  
Northern And Southern Hemispheres

Relevance. Influenza is characterized by global distribution and the difference in its seasonality in countries with temperate and tropical climates. The importance of studying antigenic variation of influenza viruses due to the fact that changes in the antigenic structure is an evolutionary mechanism of adaptation of the virus to ensure its survival and cause annual epidemics.Aims. The Aim of this study was to identify the peculiarities of the geographical spread of influenza (seasonal), etiology and the rate of antigenic variability of influenza viruses A and B.Materials and methods. Based on data from WHO Reference research centers, information was collected on circulating influenza virus strains from 1975 A(H3N2), 1977 A(H1N1)pdm09 and type B of the Yamagata and Victoria lines from 1987 to 2019, as well as data on the number of all identified influenza viruses and individual strains circulating in the Northern and Southern hemispheres from 2008 to 2018.Results and discussion. Analysis of the global spread of influenza, its etiology and antigenic variability of viruses, according to WHO, showed that the influenza A(H1N1)pdm09 virus was the main causative agent of epidemics and regional outbreaks in seasons of high influenza activity in all countries except the United States and Canada, where influenza A(H3N2) and B viruses dominated in countries with severe seasonality, the change of season led to a change in the etiology of influenza, and in tropical countries, the A(H1N1)pdm09 virus more often remained dominant in all seasons of the year.Conclusions. The pronounced seasonality of influenza in Northern countries and its absence in tropical countries, where regional outbreaks prevailed in all seasons of the year, were confirmed. Low antigenic variability of influenza A(H1N1)pdm09 strains was confirmed, and the highest – A(H3N2). Among influenza B strains in the Victoria line had less antigenic variability, because the duration of its circulation before the appearance of a new drift variant was longer than that of the Yamagata line. The tendency to increase the total duration of circulation of influenza viruses B/Victoria, A(H1N1)pdm09 and B/Yamagata due to increased circulation before the emergence of new drift variants is shown.

scholarly journals Whole-Genome Sequences of Influenza A(H1N1)pdm09 Virus Isolates from Kerala, India

2017 ◽  
Vol 5 (28) ◽  
Author(s):  
Sara Jones ◽  
Raji Prasad ◽  
Anjana S. Nair ◽  
Sanjai Dharmaseelan ◽  
Remya Usha ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Analysis ◽  
Influenza A ◽  
Whole Genome Sequence ◽  
Whole Genome ◽  
H1n1 Pandemic ◽  
Genome Sequences ◽  
Influenza A H1n1 ◽  
Virus Isolates ◽  
New Mutations

ABSTRACT We report here the whole-genome sequence of six clinical isolates of influenza A(H1N1)pdm09, isolated from Kerala, India. Amino acid analysis of all gene segments from the A(H1N1)pdm09 isolates obtained in 2014 and 2015 identified several new mutations compared to the 2009 A(H1N1) pandemic strain.

scholarly journals Planning for the Control of Pandemic Influenza A (H1N1) in Los Angeles County and the United States

2011 ◽  
Vol 173 (10) ◽  
pp. 1121-1130 ◽  
Author(s):  
D. L. Chao ◽  
L. Matrajt ◽  
N. E. Basta ◽  
J. D. Sugimoto ◽  
B. Dean ◽  
...  
Keyword(s):  
United States ◽  
Los Angeles ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Los Angeles County ◽  
The United States ◽  
Influenza A H1n1
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