AN OUTBREAK OF GROUP-C ROTAVIRUS GASTROENTERITIS AMONG ADULTS LIVING IN VALENTIM-GENTIL, SAO-PAULO STATE, BRAZIL

An outbreak of gastroenteritis affecting adults and children occurred in the small city of Valentim Gentil, Sao Paulo, Brazil, in 1993, Nine teen faecal samples (from 10 cases and 9 contacts) were examined by di rect electron microscopy (DEM), immune electron microscopy (IEM), poly acrylamide gel electrophoresis (PAGE), and enzyme-linked immunosorbent assay (ELISA) for group A and C rotaviruses, DEM detected rotavirus i n 6 of the 10 cases and in none of the contacts. All of the samples we re negative for group A rotavirus by ELISA, Analysis by PAGE showed an electrophoretic profile suggestive of group C rotavirus in two cases. Group C rotavirus was identified by IEM in 4 of the cases and in 1 of the contacts, All of the samples were submitted to ELISA for group C rotavirus, This resulted in a total of 10 positives - 7 for diarrhoeal cases and 3 for contacts, This outbreak was strongly associated with group C rotavirus. The importance of combining different diagnostic me thods is emphasised.