Rotavirus serotypes and electrophoretypes among children attending three paediatric hospitals in Belem, Brazil.

From March to September 1988 stool specimens of 101 hospitalized diarrhoeic infants and children, aged 1-24 months were examined by enzyme-linked immunosorbent assay (ELISA) for the presence of rotavirus antigen. This agent was found in 40 (40 per cent) of the 101 episodes of acute diarrhoea, and strains were both characterized by analysis of RNA in polyacrilamide gel and serotyped by ELISA using serotype-specific monoclonal antibodies. The highest frequency of rotavirus positivity was 80 per cent in the 16-18 month age group. All 11 (28 per cent) serotyped strains belonged to serotype 3 whereas absence of Vp7, the major outer capsid glycoprotein, did not allow serotyping in 29 (73 per cent) of the 40 rotavirus-positive specimens. Four distinct electrophoretypes were detected and the predominant one had the IbIIbIIIgIV a profile, accounting for 62 per cent of the classified strains. Unclear patterns did not allow us to determine the electrophoretype of six rotavirus strains. The clinical picture in study children was in general of moderate/severe nature.