Objectives: In 2006 the rotavirus vaccine was included in the Brazilian Immunization Program. The aim of this study was to report the results of a 5-year surveillance study of rotavirus strains in children < 5 years with acute gastroenteritis from day care centers in the state of São Paulo, Brazil.
Methods: This retrospective study was conducted with 30 day care centers from 2004 to 2008 with convenient surveillance fecal specimens, investigated by ELISA, SDS-PAGE, RT-PCR and gene sequencing to genotype characterization.
Results: Rotavirus infection was detected in 28.3% of samples (38/134). The most frequent genotypes detected were G9P[8] and G1P[8] in 2004; G1P[8] in 2005; GNTP[NT] in 2006; G2P[4] in 2007; and there were no cases in 2008. Mixed infections were not observed. Detection rate declined from 65.7% (23/35) in 2004 to 50% (9/18) in 2007.
Conclusions: Genotype distribution varied according to collection year, accompanied by a reduction in detection rate. Use of rotavirus vaccine requires implementation of post-marketing surveillance to monitor rotavirus strain diversity and its efficacy against possible new emerging genotypes.