Rotavirus-associated infantile diarrhea in Uberaba, Minas Gerais, on the wake of the Brazilian vaccination program

Abstract Background Rotaviruses are major causes of diarrhea in children for which vaccines were developed and are currently in use. Objectives To investigate the genotypes of rotavirus strains causing dehydrating diarrhea in children in Uberaba, Triângulo Mineiro region, Minas Gerais, during 2005–2006. Methods Rotavirus-associated diarrhea was investigated in fecal specimens by PAGE and strains were characterized for their genotype by RT-PCR and PCR-typing assays. Results Rotavirus was detected in 15% (39/260) of the fecal specimens by PAGE: 64% of the specimens presented short electrophoretic patterns and G2P[4] genotype; and 36% presented long electropherotypes and G1P[8], G9P[8], G4P[9] and two strains with sill undetermined G and P[8] genotype. A change in the dominant electrophoretic pattern was observed, shifting from long to short patterns and coinciding with the highest incidence of diarrheal cases. Conclusions Those are the first data on rotavirus strains circulating in the Triângulo Mineiro region. They were obtained over a 16-month period that included the first 10 months after the launch of the national rotavirus immunization program that uses a monovalent G1P[8] attenuated vaccine strain. These results should further our understanding of the dynamics of rotavirus strains and help interpreting the significance of the program.