GEOGRAPHIC-DISTRIBUTION OF HUMAN ROTAVIRUS VP4 GENOTYPES AND VP7 SEROTYPES IN 5 SOUTH-AFRICAN REGIONS

The rotavirus outer capsid proteins elicit the production of neutraliz ing antibodies and are known to play a role in inducing resistance to disease. In this study, cDNA probes directed at the six most common hu man rotavirus VP7 serotypes (G1 to G4, G8, and G9) and five human rota virus VP4 genotypes (P4, P6, P8, P9, and P10) were utilized. Hybridiza tion analysis of 572 human rotavirus strains collected from five regio ns in South Africa was performed to determine the distribution of the VP7 serotypes and VP4 genotypes in nature. VP7 serotype G1 was identif ied most frequently, occurring in 51% of the rotavirus strains tested. VP7 serotypes G2 and G4 occurred in similar numbers, although their d istribution varied regionally. Few serotype G3 strains and no G8 or G9 strains were identified. The P8 VP4 genotype occurred most frequently overall (66%), and the P4 genotype was detected next most frequently. The P6 genotype was identified in 28 symptomatically infected neonate s and in 8 symptomatic infants. Few P9 strains were identified. The po tential for reassortment events was demonstrated by dual infections wi th different viruses.