Outbreak of typhoid fever in Trinidad in 1971 traced to a commercial ice cream product


Andrew Taylor Jr, Alejandro Santiago, Principal Medical Officer, Abel Gonzales-Cortes and Eugene J. Gangarosa


In April 1971, a nationwide outbreak of typhoid fever involving 132 persons occurred in Trinidad; there were no deaths. Eighty per cent of cases occurred in children ages 5–14, and more than 90% of ill persons lived or went to school in the main towns or in smaller communities along their connecting roads. The epidemic curve suggested a common source, and a series of food preference questionnaires implicated a nationally distributed ice cream product. Further investigation indicated that the product was distributed on only one day, March 23. The mean incubation period was 19 days, and the attack rate for those at risk was slightly greater than 1%. Samples of the ice cream product obtained a month after the outbreak were found to contain greater than 1100 Escherichia coli per 100 ml. Inspection of the plant revealed frequent hand contact with the product and an absence of pasteurization facilities. Although rectal swabs and stool cultures obtained after purgation from employees failed to identify the carrier, epidemiologic evidence suggested that an employee in the plant, rather than a contaminated ingredient, was the source of the outbreak. This outbreak emphasizes the need for mandatory pasteurization of milk and ice cream products, especially when strict sanitary procedures cannot be adhered to or enforced.


Click here to view the article.