Winter vomiting disease in Florida students.

On 14 November 1967 an investigation was begun at the University of South Florida to determine the cause of an increased number of gastrointestinal illnesses on campus. An estimated 300 students suddenly became ill with nausea, vomiting, abdominal pain, and diarrhoea. While at first food poisoning was suspected, no common food, water, or toxic exposure could be found. The data collected were most consistent with Winter Vomiting Disease. This entity is characterized by acute gastrointestinal illnesses which may occur in epidemic form in residential schools between September and March. Most investigators suspect that a viral agent is responsible for the illnesses, though attempts to isolate a virus have been unsuccessful. The incubation period in the University outbreak was estimated at 28 hr., and contact was the most likely mode of transmission. The outbreak illustrated that Winter Vomiting Disease in residential institutions may be an accentuation of the gastrointestinal illnesses occurring simultaneously in the community at large.