Foodborne gastroenteritis of unknown aetiology: a virus infection?

In almost a quarter of outbreaks of gastroenteritis reported to the Public Health Laboratory service by medical officers of environmental health and environmental health officers as possible foodborne infection in 1980 food poisoning organisms were not isolated. In a third of this group the incubation period was longer than the usual range for bacterial food poisoning organisms, and possibly some of the outbreaks were viral in origin. Viruses were detected by electron microsocpy in 88% of faecal specimens from similar outbreaks associated with shellfish but in only 23% of specimens from outbreaks associated with other foods. Recommendations are made for future investigation of such outbreaks including the collection of epidemiological data and specimens for virological study.