Poor outcome of acute respiratory infection in young children with underlying health condition in Brazil.

Objectives: It is well established that respiratory viruses are an important cause of hospitalizations in young children worldwide, but data are limited on the contribution of specific viruses to severe illness in South America. We describe clinical and laboratory findings from prospective surveillance for acute respiratory infections at a tertiary hospital in São Paulo, Brazil.

Methods: We screened children < 2 years old with acute respiratory tract infections admitted to an urban tertiary hospital for respiratory viruses from March 2008 through February 2010, using polymerase chain reaction assays.