BACKGROUND The 2014-2015 influenza season was distinguished by an epidemic of antigenically-drifted A(H3N2) viruses and vaccine components identical to 2013-2014. We report 2014-2015 vaccine effectiveness (VE) from Canada and explore contributing agent-host factors. METHODS VE against laboratory-confirmed influenza was derived using a test-negative design among outpatients with influenza-like...

BACKGROUND There are few prospectively collected data comparing illnesses caused by different subtypes of influenza. We compared the clinical presentation and outcomes of subjects with primarily outpatient-attended influenza A and B infections during four consecutive influenza seasons (2004-2005 through 2007-2008). METHODS Patients were prospectively enrolled and tested for influenza followin...

BACKGROUND Households play a major role in community spread of influenza and are potential targets for mitigation strategies. METHODS We enrolled and followed 328 households with children during the 2010-2011 influenza season; this season was characterized by circulation of influenza A (H3N2), A (H1N1)pdm09 and type B viruses. Specimens were collected from subjects with acute respiratory illn...

BACKGROUND Influenza A viruses are medically important viral pathogens that cause significant mortality and morbidity throughout the world. The recent emergence of a novel human influenza A virus (H1N1) poses a serious health threat. Molecular tests for rapid detection of this virus are urgently needed. METHODS We developed a conventional 1-step RT-PCR assay and a 1-step quantitative real-tim...

BACKGROUND Influenza data gaps in sub-Saharan Africa include incidence, case fatality, seasonal patterns, and associations with prevalent disorders. METHODS Nasopharyngeal samples from children aged <12 years who were admitted to Kilifi District Hospital during 2007-2010 with severe or very severe pneumonia and resided in the local demographic surveillance system were screened for influenza A...

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) H...

background: influenza virus is a major infectious pathogen of the respiratory system causing a high degree of morbidity and mortality annually. the worldwide vaccines are decided and produced annually by world health organization and licensed companies based on the samples collected from all over the world. the aim of this study was to determine phylogenecity and heterogenecity of the circulati...

A key priority in infectious disease research is to understand the ecological and evolutionary drivers of viral diseases from data on disease incidence as well as viral genetic and antigenic variation. We propose using a simulation-based, Bayesian method known as Approximate Bayesian Computation (ABC) to fit and assess phylodynamic models that simulate pathogen evolution and ecology against sum...

H3 subtype influenza A virus is one of the main subtypes that threats both public and animal health. However, the evolution and pathogenicity of H3 avian influenza virus (AIV) circulating in domestic birds in China remain largely unclear. In this study, seven H3 AIVs (four H3N2 and three H3N8) were isolated from poultry in live poultry market (LPM) in China. Phylogenetic analyses of full genome...

The virus surface protein neuraminidase (NA) is a main subtype-specific antigen in influenza type A viruses. Neuraminidase functions as an enzyme to break the bonds between hemagglutinin (HA) and sialic acid to release newly formed viruses from infected cells. In this study, NA genes from the H3N2 subtype virus were sequenced and NA proteins were screened for B-cell epitopes and assessed based ...