Molecular epidemiology of the human group A rotavirus in the Paraná State, Brazil

From January/2000 to December/2003, 550 diarrheic fecal samples from the children and adults were collected in several geographical regions of Paraná State, Brazil. The enzyme immunoassay showed 120 (21.8%) samples positive for the group A rotaviruses. One hundred and fourteen samples were genotyped by multiplex-nested-PCR assay. The highest frequency (77.5%) of the positive samples (n=93) was observed in the children under 5 years old. Rotavirus diarrhea was more frequent in the cold and dry seasons of the four evaluated years. The most frequent genotypes were: G1 (50.9%), G4 (9.6%), G9 (7.0%), G2 (1.7%), G3 (0.9%), P[ 8] (71.9%), and P[ 4] (3.5%). The P[ 8] G1 (46.5%) and P[ 8] G4 (9.6%) were the main combinations found to P and G genotypes. The mixed infections, characterized by the rotaviruses with more than one genotype G or P, and nontypeable rotavirus were observed in 8.8, 3.5, and 16.7% of the samples, respectively. The identification of the G9 genotype in the rotavirus strains tested along the four years of studies ratifies the emergency of this genotype also in Paraná State, South region of Brazil, as the worldwide.