OUTBREAK INVESTIGATION - THE NEED FOR QUICK AND CLEAN EPIDEMIOLOGY

Epidemiological investigations of outbreaks of infectious disease have to be carried out rapidly but must be methodologically sound. In 14 o f 25 consecutive Salmonella outbreaks in Wales from 1986 to 1990 case- control or cohort studies were undertaken. Food vehicles of infection were identified by statistically significant associations with cases i n 13 of the 14, including three outbreaks where there were less than 1 0 cases. The particular problems of epidemiological field investigatio ns are discussed.