The role of outbreaks in developing food safety policy: population based surveillance of salmonella outbreaks in Wales 1986-98

Tn developing public policy on food safely, systematic identification and t horough investigation of all general outbreaks is necessary in order to avo id bias towards highly publicised outbreaks. In Wales, from 1986 to 1998, 8 7 general foodborne outbreaks of salmonellosis were identified. Most outbre aks occurred at functions or were associated with small catering outlets su ch as bakeries and sandwich bars. In 50 outbreaks, a vehicle of infection w as confirmed microbiologically and/or epidemiologically. The most common fo od vehicles were those containing shell eggs. Salmonella enteritidis outbre aks were significantly more likely than outbreaks of other serotypes to be associated with vehicles containing shell eggs, suggesting that eggs were a lso the source of infection in many outbreaks. The routine use of analytica l epidemiological studies to identify vehicles in outbreaks is recommended.