Surveillance of foodborne disease in the United States, 1971-1972

Since 1966 the Center for Disease Control (CDC) has maintained surveillance of outbreaks of foodborne disease with the objective of preventing such outbreaks through an understanding of the responsible etiologic agents and contributing factors. In 1968 a standard form for reporting outbreaks to the CDC was made available to all state health departments. A foodborne disease outbreak is defined as an incident in which 2 or more persons experienced a similar illness, usually gastrointestinal, after ingesting a common food; and epidemiologic analysis implicated food as the source of the illness. Data on single cases, except for botulism and chemical poisonings, were not included. In 1972, 301 outbreaks affecting 14,559 persons were reported from 38 states. In contrast, in 1971, 320 outbreaks involving 13,453 persons were reported from 47 states. Laboratory confirmation was obtained in 45% of outbreaks in 1972 and in 29% of outbreaks in 1971. Bacterial pathogens accounted for over two thirds of laboratory confirmed outbreaks and over 95% of laboratory confirmed cases in both years. Chemical food poisonings were the second most commonly confirmed cause of outbreaks in both years. In 1972 and 1971 salmonellae and Staphylococcus aureus together were responsible for over 50% of confirmed outbreaks.