Outbreak of salmonellosis after a wedding party, Bavaria, Germany, summer 2010: the importance of implementing food safety concepts

An outbreak of salmonellosis in the summer of 2010 after a wedding party in Bavaria, Germany, was investigated, to identify vehicles and source of the outbreak and any flaws in food safety procedures. A cohort study targeting all wedding participants was carried out in addition to laboratory and environmental investigations. The overall attack rate was 59% (52/88). A group of buffet dishes containing mayonnaise was associated with the highest relative risk: 6.6 (95% CI: 1.7-25.0). Subtyping of a subset of Salmonella isolates cultured from stool samples from wedding participants and catering staff and from food samples showed the isolates to be indistinguishable (S. Enteritidis, lysotype 4/6, ribotype 3). European laws require food business operators to establish and implement food safety procedures. Investigation of the practices of the catering company revealed a lack of staff training and the absence of records of a food safety concept. Non-edible flower decorations in cold dishes were identified as a potential source of secondary contamination because their cultivation and processing are not subject to the food safety regulations minimising the risk of contamination of crops intended for human consumption. The outbreak demonstrated the importance of staff training and food safety concepts to identify and mitigate hazards to food safety.