An institutional food-poisoning outbreak

ABSTRACT

Based on the clinical, epidemiologic, and laboratory findings, the investigation team was of the considered opinion that the cause of the outbreak was food infection rather than intoxication. The grouping of cases in relation to a particular event; the explosive nature of the outbreak; the equal susceptibility of all ages, sexes, and occupational groups; the median incubation period of 13 hours; the clinical picture of gastroenteritis with fever, chills, and headache, the fever being high in range and with an average duration of 2 days; the isolation of the Ballerup-Bethesda group of organisms from stools of some cases; the serologic study which showed significantly higher titer of antibodies among cases than among a control group which was not infected; and the presence of conditions ideal for contamination and subsequent bacterial growth during the preparation of the food items suspected as the probable vehicle of infection all tend to to support the hypothesis of food infectionThe actual source of infections has not been determined with absolute certainly and the manner of contamination and transmission of the causative organisms are only matters of conjecture, because delayed reporting had made their demonstration by direct evidence technically difficult. However, these should not detract from the soundness of the conclusions drawn. After all, epidemiologic investigations in actual working situations are perhaps seldom, if ever, perfect and complete. As Wade Hampton Frost had written, "Epidemiology is something more than the total of its established facts......it includes ......chains of inferences which extend more or less beyond the bounds of direct observation." (Conclusion)