An island-wide epidemic of salmonellosis in Trinidad traced to contaminated powdered milk

Between March 1 and November 30, 1973, an epidemic of salmonella derby gastroenteritis occurred in Trinidad. Approximately 3,000 people were affected. Cases occurred throughout the island roughly in proportion to the population, but most were in infants and small children. Household surveys of cases and a sample survey of controls indicated that the consumption of powdered milk was significantly associated with illness. Further studies showed that 7 different brands of imported powdered milk packaged at a single processing plant near Port-of-Spain were, as a group, significantly associated with salmonellosis. Investigations at the implicated processing plant disclosed several packaging procedures that could have permitted contamination during canning, but the specific mode of contamination could be demonstrated (AU)