Whereas in Europe and North America most of the influenza cases are reported between December and March, in tropical and subtropical regions such as in Brazil [1] or in Hong Kong [2] cases are seen throughout the year. Epidemic peaks in the tropical areas mostly occur in between those found in the Northern and Southern hemispheres. A recent survey over 7 years in Brazil showed that annual peaks...

background: a new pandemic influenza a (h1n1) emerged in april 2009, causing considerable morbidity and mortality. since mutations in the haemagglutinin (ha) may influence the antigenicity and pathogenicity of the virus, continued epidemiological and molecular characterization for the effective control of pandemic flu and developing of more appropriate vaccine is crucial. objective: to monitor ...

results: of 655 samples, 69 (10.53%) had positive results for human influenza a virus, and 5 (0.7%) samples had positive results for influenza b. of those 69 samples with positive results for influenza a viruses, 45 (6.8%) were h3n2, and 24 (3.6%) were h1n1 subtypes. in this study most cases with positive results were less than 20 years. the sample positive included 49% males and 51% females. t...

The pandemic novel influenza A (H1N1) infection was considered widespread in Brazil on July, 2009. Since then, 9.249 cases were confirmed in Brazil, most of them concentrated in São Paulo. The Hospital das Clínicas of the University of São Paulo is a reference center for H1N1 cases in São Paulo. The purpose of this review is to analyze the evidence concerning diagnosis, prevention, and treatmen...

conclusions: among confirmed patients with influenza a (h1n1), the most common symptoms were sequentially cough, dyspnea, chill and myalgia. pcr did not show high sensitivity in diagnosis of influenza a (h1n1) infection. the risk factor with the highest prevalence was heart disease followedby cigarette smoking and hematologic disorder. the mean age of these patients was about 38. results: rt pc...

Asia is considered an important source of influenza A virus (IAV) pandemics, owing to large, diverse viral reservoirs in poultry and swine. However, the zoonotic origins of the 2009 A/H1N1 influenza pandemic virus (pdmH1N1) remain unclear, due to conflicting evidence from swine and humans. There is strong evidence that the first human outbreak of pdmH1N1 occurred in Mexico in early 2009. Howeve...

T cell epitopes have been found to be shared by circulating, seasonal influenza virus strains and the novel pandemic H1N1 influenza infection, but the ability of these common epitopes to provide cross-protection is unknown. We have now directly tested this by examining the ability of live seasonal influenza vaccine (FluMist) to mediate protection against swine-origin H1N1 influenza virus infect...

Background and Aims: Influenza (flu) is a respiratory infection in mammals and birds. It is caused by an RNA virus in the family Orthomyxoviridae. The virus is divided into three main types. Influenza virus type A is found in a wide variety of bird and mammal species and can undergo major shifts in immunological properties. Hemagglutinin (HA) is an important influenza virus surface antigen that...

Cell-mediated immunity to influenza A/USSR (H1N1) virus was assessed by measuring transformation response and interferon production by Ficoll-Hypaque-purified peripheral blood lymphocytes from children and adults. Lymphocyte transformation was found to be related to the individual's previous experience with H1N1 influenza virus. Lymphocyte cultures, obtained from adults who had their last conta...