Group A streptococcal skin infection outbreak in an abattoir: lessons for prevention.

During a group A streptococcus (GAS) outbreak 21 abattoir workers developed skin infections. The unusual outbreak strain (emm 108.1) was cultured from five workers and four persons in the community with links to the abattoir. The attack rate was 26% in the lamb line. Communal nailbrushes were neither routinely disinfected nor changed, and had high bacterial counts. A cohort study found a higher risk from working in the gutting area and getting cuts on hands more than weekly. Despite high bacterial counts daily nailbrush use had a lower risk, as did always wearing disposable gloves. Working in the gutting area (OR 11.44) and nailbrush use at least once a day (OR 0.04) were significant in the multivariate model. Transmission of infection is likely to have occurred on carcasses. GAS infection among abattoir workers was once common. Simple hygiene measures, such as nailbrush use, may reduce the impact of future outbreaks.

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

In developing public policy on food safety, systematic identification and thorough investigation of all general outbreaks is necessary in order to avoid bias towards highly publicised outbreaks. In Wales, from 1986 to 1998, 87 general foodborne outbreaks of salmonellosis were identified. Most outbreaks occurred at functions or were associated with small catering outlets such as bakeries and sandwich bars. In 50 outbreaks, a vehicle of infection was confirmed microbiologically and/or epidemiologically. The most common food vehicles were those containing shell eggs. Salmonella enteritidis outbreaks were significantly more likely than outbreaks of other serotypes to be associated with vehicles containing shell eggs, suggesting that eggs were also the source of infection in many outbreaks. The routine use of analytical epidemiological studies to identify vehicles in outbreaks is recommended.