BACKGROUND An age bias toward children and young adults has been reported for infection and hospitalizations with pandemic H1N1 influenza (A[H1N1]pdm) in the 2009 and 2010 influenza seasons in the Southern and Northern Hemispheres. Serological analysis of prepandemic samples has shown a higher incidence of cross-reactive antibodies to A(H1N1)pdm virus in older populations; conserved T cell epit...

BACKGROUND Limited data are available on disease characteristics and outcomes of children with 2009 pandemic influenza A(H1N1) virus infection (pandemic H1N1 influenza) who have required hospital admission. METHODS We reviewed the charts of 58 children with pandemic H1N1 influenza admitted to a large pediatric hospital in Ontario, Canada, between May 8 and July 22, 2009. We compared risk fact...

The adaptive evolution of the hemagglutinin (HA) segment of the human influenza H1N1 and H3N2 viruses is not well understood due to antigenic mutations under selection pressures. This paper identified significant antigenic selection sites and discussed the structural relevance of these mutations. We discovered four positively selected sites for H1N1 (position 206 for the 1A lineage - 2009 swine...

The spring of 2009 witnessed the emergence of a novel influenza A(H1N1) virus resulting in the first influenza pandemic since 1968. In autumn of 2010, the 2009 novel H1N1 influenza strain re-emerged. We performed a retrospective time-series analysis of all patients with laboratory-confirmed H1N1 influenza who presented to our institution during 2009. Cases of influenza were assembled into 3-day...

Highly pathogenic influenza H5N1 virus continues to pose a threat to public health. Although the mechanisms underlying the pathogenesis of the H5N1 virus have not been fully defined, it has been suggested that cytokine dysregulation plays an important role. As the human respiratory epithelium is the primary target cell for influenza viruses, elucidating the viral tropism and innate immune respo...

Background Pandemic influenza H1N1/09 emerged in April 2009 and spread widely in Australia and New Zealand. Although an unprecedented number of cases required intensive care, comparative community-based studies with seasonal influenza strains have not shown any significant differences in clinical symptoms or severity. Methods The authors performed active surveillance on confirmed influenza-rel...

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...

Schaefer R., Zanella J.R.C., Brentano L., Vincent A.L., Ritterbusch G.A., Silveira S., Caron L. & Mores N. 2011. Isolation and characterization of a pandemic H1N1 influenza virus in pigs in Brazil. Pesquisa Veterinária Brasileira 31(9):761-767. Embrapa Swine and Poultry Research Center, BR153, Km110, Vila Tamanduá, Concórdia, SC 89700000, Brazil. E-mail: [email protected] Influenza A viru...

PURPOSE The purpose of this article is to describe the clinical and epidemiologic features and outcomes among children hospitalized with pandemic influenza A/H1N1 2009 infection. METHODS We retrospectively reviewed the charts of hospitalized pediatric patients (<18 years) diagnosed with pandemic influenza A/H1N1 2009 infection by reverse-transcriptase polymerase chain reaction at a tertiary h...

BACKGROUND Pregnant women are a high-risk group for morbidity and mortality from influenza. During the current pandemic of H1N1 influenza, few cases of H1N1 have been reported in pregnancy. CASES We report two cases of H1N1 influenza which occurred in single institution in the course of one month. The first patient developed acute respiratory distress syndrome, required intubation, and eventu...