CHARACTERIZATION OF ROTAVIRUSES RECOVERED FROM NEONATES WITH SYMPTOMATIC INFECTION

An unusually high number of diarrhoeal stools were obtained from neona tes at different maternity units in Pretoria during late 1986 and the winter of 1987 and tested for the presence-of rotavirus infection. Lat ex agglutination assay revealed rotavirus in 67% (93/139) of the stool s from newborn babies. Gel electrophoresis of the rotavirus genome sho wed that a genomically stable strain of rotavirus was associated with the diarrhoeal illness in all maternity units investigated. Determinat ion of the VP6 subgroup specificity using monoclonal antibodies demons trated that all strains were of subgroup If. Examination of the VP4 an d VP7 rotavirus genes, which encode for the outer capsid neutralisatio n proteins of the virus, was conducted by hybridisation analysis using probes directed at the divergent regions of the two genes. These resu lts showed the presence of a VP7 serotype G4 rotavirus strain with a P 6 VP4 genotype - the putative 'attenuated' VP4 gene allele circulating in all maternity units studied.