The relative frequency of subgroup I and II rotaviruses in black infants in South Africa.

Between March 1983 and December 1986, a total of 1571 stool specimens were collected from black South African infants and young children with acute gastroenteritis, and tested for the presence of rotavirus. Monoclonal antibodies against the major inner capsid protein were used in an enzyme linked immunosorbent assay to determine the subgroup specificity of the rotavirus isolates. Subgroup II rotaviruses occurred more frequently than subgroup I isolates (74.4% vs 12.3%), while 13.3% could not be typed and may indicate the presence of a third subgroup. Two of the subgroup I isolates had a long RNA profile (ie, faster moving gene segment 11) typical of the subgroup II human rotaviruses, and a single subgroup II strain had a short RNA profile possibly indicating an in vivo rotavirus reassortant.