NORWALK VIRUS-INFECTION IN VENEZUELA

The presence of antibodies against Norwalk virus (NV) was studied in s era from different Venezuelan populations, using an enzyme immune-assa y (EIA) based on recombinant NV protein. Antibodies to NV were found i n 47%-53% of urban subjects from Caracas, 83% of rural subjects from t he west of the country, and 73%-93% of Amerindian subjects. The preval ences found in the rural and Amerindian groups were significantly high er than that in the urban group. Although about 50% of the children st udied were seropositive for NV by the age of 5 years, only four (0.4%) of 1120 faecal samples from children with diarrhoea which were tested for the presence of NV antigen by sandwich EIA were found positive. A n increase of at least 4-fold in the titre of anti-NV IgA was found in three (5%) of 61 pairs of sera taken during and I month after an acut e episode of diarrhoea not due to rotavirus. NV was therefore not a pr edominant aetiological cause of gastro-enteritis in young children in Venezuela between 1993 and 1995, although it can be the cause of diarr hoea in infants.