Three clusters of Salmonella Enteritidis ST11 infections linked to chicken meat and chicken meat products

Abstract

From 1 January-24 October 2023, 335 laboratory-confirmed Salmonella Enteritidis ST11 cases belonging to three distinct microbiological clusters have been reported in 14 EU/EEA countries, the United Kingdom and the United States, affecting all age groups. Most interviewed cases reported consumption of chicken meat, including chicken kebabs. Nine cases in three countries were hospitalised and one case in Austria died, highlighting the potential for severe and fatal infections from this outbreak. Following the food exposure information and the national investigations in 2023, the food safety authorities in Austria, Denmark and Italy investigated 10 food products (six contaminated by Salmonella Enteritidis ST11 cluster 1 and/or cluster 2), seven final producers in Poland and one in Austria. Traceability information revealed that three Salmonella-contaminated kebabs shared a number of Polish food business operators. The trading link of the suspected kebab suggests one or more common source(s)/point(s) of contamination in Austria, Denmark, and Italy. Following the collection of genomic information, the cluster analysis revealed the presence of the outbreak strains in the food chain in multiple European countries. Most positive foods sampled in 2022-2023 with shared epidemiological data originated from Poland. Given the information collected, contaminated chicken kebab and chicken meat are the plausible vehicles of the human infections reported in these three clusters. In the absence of conclusive microbiological evidence and comprehensive traceability, the role of the identified final producers, their meat suppliers, and the possible involvement of other food business operators as sources of the infections could not be confirmed or excluded. Further investigations are needed to identify the root cause of the contamination and the source of infections, which is crucial for prompt implementation of targeted effective control and corrective measures. As the source(s) have not been identified, new cases are likely to occur in this prolonged multi-country outbreak.