Hospital-based Surveillance to Evaluate the Impact of Rotavirus Vaccination in São Paulo, Brazil

BACKGROUND:Brazil implemented routine immunization with the human rotavirus vaccine, Rotarix, in 2006 and vaccination coverage reached 81% in 2008 in São Paulo. Our aim was to assess the impact of immunization on the incidence of severe rotavirus acute gastroenteritis (AGE). METHODS:We performed a 5-year (2004–2008) prospective surveillance at a sentinel hospital in São Paulo, with routine testing for rotavirus in all children less than 5 years of age hospitalized with AGE. Genotypes of positive samples were determined by reverse transcription polymerase chain reaction. RESULTS:During the study, 655 children hospitalized with AGE were enrolled; of whom 169 (25.8%) were positive for rotavirus. In the postvaccine period, a 59% reduction in the number of hospitalizations of rotavirus AGE and a 42.2% (95% confidence interval [CI], 18.6%–59.0%; P = 0.001) reduction in the proportion of rotavirus-positive results among children younger than 5 years were observed, with the greatest decline among infants (69.2%; 95% CI, 24.7%–87.4%; P = 0.004). Furthermore, the number of all-cause hospitalizations for AGE was reduced by 29% among children aged