Genetic diversity and molecular epidemiology of respiratory syncytial virus over four consecutive seasons in South Africa: identification of new subgroup A and B genotypes

The molecular epidemiology of respiratory syncytial virus (RSV) was studied over four consecutive seasons (1997-2000) in a single tertiary hospital in South Africa: 225 isolates were subgrouped by RT-PCR and the resulting pro ducts sequenced. Subgroup A predominated in two seasons, while A and B co-c irculated approximately equally in the other seasons. The nucleotide sequen ces of the C-terminal of the G-protein were compared to sequences represent ative of previously defined RSV genotypes. South African subgroup A and sub group B isolates clustered into four and five genotypes respectively. One n ew subgroup A and three new subgroup B genotypes were identified. Different genotypes co-circulated in every season. Different circulation patterns we re identified for group A and B isolates. Subgroup A revealed more variabil ity and displacement of genotypes while subgroup B remained more consistent .