Epidemiology of human infection with the novel virus influenza A (H1N1) in the Hospital das Clínicas, São Paulo, Brazil--June-September 2009.

The pandemic novel influenza A (H1N1) infection was considered widespread in Brazil on July 16, 2009. Since then, 46,810 cases of acute respiratory syndrome have been reported in Brazil, most of them concentrated in São Paulo. Through September 16, we have confirmed 9,249 cases of novel influenza A H1N1in Brazil, including 699 deaths. The mortality rate observed in Brazil is 0.47/100,000 inhabitants and varies according to region. In this period, São Paulo registered 3733 cases (40.3% of the total) of novel influenza A (H1N1) infection and 327 deaths, reflecting a mortality rate of 0.79/100,000 inhabitants. The Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HC) is a reference center for H1N1 cases in São Paulo. During the winter of 2009, 472 patients in this hospital were diagnosed with H1N1 infection; of these, 210 were admitted, and 16 died. To control this pandemic and to provide adequate care for these patients, the Hospital das Clínicas implemented "bundles" including prevention strategies, an epidemiologic surveillance service, availability of fast diagnosis, antiviral treatment and training of staff. The purpose of this manuscript is to describe the epidemiologic features of novel human influenza A (H1N1) infection in the Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo during the winter period of the 2009 pandemic.