Rapid outbreak assessment: Multi-country outbreak of Salmonella Virchow ST16 infections linked to the consumption of meat products containing chicken meat

Risk assessment
Cite:

European Centre for Disease Prevention and Control, European Food Safety Authority, 2023. Multi-country outbreak of Salmonella Virchow ST16 infections linked to the consumption of meat products containing chicken meat – 30 March 2023.

Since June 2017, a persistent cross-border outbreak of Salmonella Virchow ST16 has been ongoing in five European Union/European Economic Area (EU/EEA) countries, the United Kingdom (UK), and the United States (US). A total of 210 cases have been reported from the following countries: Denmark (2), France (111), Germany (26), Ireland (4), the Netherlands (34), the UK (32), and the US (1). Among the interviewed cases (55), hospitalisation rates ranged from 16.7% (2/12) in the UK, to 29.4% (5/17) and 38.5% (10/26) in France and Germany, respectively. No deaths have been reported. A majority of cases have been linked to local restaurants serving kebab meat. The number of confirmed cases represents only a small proportion of all infections in the EU/EEA, partly due to the varying sequencing capacities of countries.

Executive summary

The comparison of the representative outbreak strains with the available genome profiles of S. Virchow ST16 from non-human isolates, revealed that most of the matching isolates belonged to broiler meat and broiler-related environments, thereby supporting the hypothesis of chicken meat as a vehicle of infections.

The available information from case interviews, traceback investigations, and whole genome sequencing (WGS) cluster analysis, showed that kebab meat products containing contaminated chicken meat are the likely vehicles of infections, and that the clone has been circulating in the EU poultry meat production chain at least in France, Germany, and the Netherlands. In the absence of batch numbers of the contaminated kebab products and related Salmonella testing information, the source(s) of the infections could not be established.

New infections are likely to occur in the EU/EEA affecting any age group, until further investigations are performed to identify the source(s) and point(s) of contamination along the chicken meat production chain, including the primary production upstream lines. This will allow appropriate control measures to be implemented.