Oswego Outbreak Case Study
The 1940 outbreak of staphylococcal gastroenteritis in the small village of Lycoming, in Oswego County, New York, may be the first example of a real outbreak that was transformed into a teaching exercise. After a church supper, most of the participants became ill with gastroenteritis. District health officers obtained food and illness histories from the 75 participants.
On April 19, 1940, the local health officer in the village of Lycoming, Oswego County, New York, reported the occurrence of an outbreak of acute gastrointestinal illness to the District Health Officerin Syracuse. Dr. A. M. Rubin, epidemiologist-in-training, was assigned to conduct an investigation. When Dr. Rubin arrived in the field, he learned from the health officer that all persons known to be ill had attended a church supper held on the previous evening, April 18. Family members who did not attend the church supper did not become ill. Accordingly, Dr. Rubin focused the investigation on the supper. He completed interviews with 75 of the 80 persons known to have attended, collecting information about the occurrence and time of onset of symptoms, and foods consumed. Of the 75 persons interviewed, 46 persons reported gastrointestinal illness.
The district health officer went to the scene immediately to verify the existence of the outbreak, and a team, including two epidemiology trainees, was assigned to make a full investigation, including food and illness histories, on April 20. Their report states: "All handlers of the ice cream were examined. No external lesions or upper respiratory infections were noted" (CDC Foodborne Outbreak Investigations). Nose and throat cultures of the two who made the ice cream mix, however, did grow S. aureus.The ingredients used to prepare the ice cream were fresh, unpasteurized milk, condensed milk, sugar, eggs, flour, chocolate, and vanilla extract. The chocolate and vanilla mixes were prepared in separate containers on April 17, the day before the supper, and left covered overnight at room temperature before being frozen. The raw milk was an unlikely source of infection,because the chocolate ice cream was not contaminated.
In any event, an attack of gastroenteritis occurred following a church supper at Lycoming. The cause of the outbreak was contaminated vanilla ice cream. The method of contamination of ice cream is not clearly understood. Whether the positive Staphylococcus nose and throat cultures occurring in the Petrie family had anything to do with the contamination is a matter of conjecture.
Friis, R. Sellers, T. (2014). Epidemiology for Public Health Practice. Jones and Bartlett Learning LLC. Pages 18, 20.
CDC Foodborne Outbreak Investigations (2012)
Field Epidemiology A Brief Overview (2010). Power Point Jones and Bartlett.