Escherichia coli O 27 in adult diarrhoea.

Escherichia coli O 27 H 7 was found in 16 stool samples submitted during a Caribbean cruise (Cruise Z) by 29 patients reporting with diarrhoea. A retrospective search revealed E. coli O 27 H 7 in 11 of 20 and 2 of 14 stool cultures from patients on two previous cruises (Y and X respectively) and in a culture from fresh cream (Cruise Y). The repeated occurrence of E. coli O 27 H 7 in the absence of any other apparent cause suggested that this serotype may have been responsible for the diarrhoea. The results of pathogenicity tests suggested that this strain elaborated heat-stable (ST) enterotoxin. The possibility that food may have been the vector is discussed.