Non-O group 1 Vibrio cholerae gastroenteritis associated with eating raw oysters

A cluster of five cases of non-O group 1 (non-O1) V. cholerae gastroenteritis occurred in one Florida locality during November 1979. Clinical findings included nausea, vomiting, and abdominal cramping in all affected persons; two had bloody diarrhea. All five persons gave a history of eating raw oysters within four days of onset of illness. A case-control study statistically associated the eating of raw oysters with development of illness (p = 0.0008); this finding was confirmed by a retrospective cohort study of patients hospitalized for diarrhea (p = 0.0001). Non-O1 V. cholerae organisms were isolated from oysters and water samples taken from areas where ill persons had obtained their oysters. In at least one instance the same serotype was isolated from a patient's stool specimen and from the water where the patient had obtained oysters. Non-O1 V. cholerae infection must be considered in the differential diagnosis of shellfish-associated gastroenteritis.