Among 368 Thai men who have sex with men with paired serum samples collected before and during the 2009 H1N1 influenza pandemic, we determined influenza A (H1N1)pdm09 seroconversion rates (≥4-fold rise in antibody titers by hemagglutination inhibition or microneutralization assays). Overall, 66 of 232 (28%) participants seroconverted after the first year of A(H1N1)pdm09 activity, and 83 of 234 ...

INTRODUCTION Since the emergence of the pandemic influenza A/H1N1/2009 virus in April 2009, diagnostic testing in many countries has revealed the rapid displacement and then replacement of circulating seasonal influenza viruses by this novel virus. MATERIALS AND METHODS In-house seasonal and pandemic influenza-specific polymerase chain reaction assays were introduced and/or developed at the M...

BACKGROUND Recent studies suggest an association between the Interferon Inducible Transmembrane 3 (IFITM3) rs12252 variant and the course of influenza infection. However, it is not clear whether the reported association relates to influenza infection severity. The aim of this study was to estimate the hospitalization risk associated with this variant in Influenza Like Illness (ILI) patients dur...

BACKGROUND Influenza viruses can generate novel reassortants in coinfected cells. The global circulation and occasional introductions of pandemic H1N1/2009 virus in humans and in pigs, respectively, may allow this virus to reassort with other influenza viruses. These possible reassortment events might alter virulence and/or transmissibility of the new reassortants. Investigations to detect such...

The purpose of this study was to understand the geographic extent, risk factors, and attack rate of the 2009 pandemic influenza A (H1N1) virus [A(H1N1)pdm09] infection in Shandong Province, China and to identify the influencing factors. A randomized serological survey of A(H1N1)pdm09 infection was carried out in August and September 2010. A total of 4,549 participants involved in the survey ...

We present the case of a 21 year-old man holidaying on the Spanish island of Mallorca, a region of high outbreak of infections with a new influenza A/H1N1 virus. Symptomatic influenza A infection, but not H1N1 positive, led to myocarditis after intimate contact with a woman with positive H1N1 titer. The electrocardiogram showed T-wave inversions in II, III, aVF and V5, V6. Serum chemistry showe...

The evolution of classical swine influenza viruses receptor specificity preceding the emergence of the 2009 H1N1 pandemic virus was analyzed in glycan microarrays. Classical swine influenza viruses from the α, β, and γ antigenic clusters isolated between 1945 and 2009 revealed a binding profile very similar to that of 2009 pandemic H1N1 viruses, with selectivity for α2-6-linked sialosides and v...

The United Kingdom (UK) is in the third season of introducing universal paediatric influenza vaccination with a quadrivalent live attenuated influenza vaccine (LAIV). The 2015/16 season in the UK was initially dominated by influenza A(H1N1)pdm09 and then influenza of B/Victoria lineage, not contained in that season's adult trivalent inactivated influenza vaccine (IIV). Overall adjusted end-of-s...

Background Outcome data from prospective follow-up studies comparing infections with different influenza virus types/subtypes are limited. Methods Demographic, clinical characteristics and follow-up outcomes for adults with laboratory-confirmed influenza A(H1N1)pdm09, A(H3N2), or B virus infections were compared in 2 prospective cohorts enrolled globally from 2009 through 2015. Logistic regre...

BACKGROUND Although the socioeconomic burden of 2009 pandemic influenza A (H1N1) was considerable, no reliable estimates have been reported. Our aim was to compared medical costs and socioeconomic burden resulting from pandemic influenza A (H1N1) 2009 with that of previous seasonal influenza. METHODS We estimated the medical costs and socioeconomic burden of influenza from May 2007 to April 2...