| In 1990 there were 57 separate outbreaks of viral gastro-enteritis over 18 days implicating raw oysters from a large oyster producing area. Of 1,750 people involved in 11 outbreaks, 550 ate oysters and of these 446 (81 %) were ill (mean incubation period 36 hours) with symptoms persisting for several days. Norwalk virus was detected in patients' stools and there was serological evidence of Norwalk viral infection in blood specimens. Remaining opened oysters (11 samples) from implicated batches were examined for standard plate count, faecal coliforms and Escherichia coli with only 1 sample complying with micro biological standards. Vibrio vulnificus and Vibrio parahaemolyticus were detected at low levels while Salmonella, Campylobacter jejuni, and... |
