28.10.2016

EFSA

A multi-country outbreak of Salmonella Enteritidis phage type (PT) 8 with multiple locus variable number tandem repeat analysis (MLVA) profiles 2-9-7-3-2 and 2-9-6-3-2, linked to eggs, is ongoing in the EU/EEA. Based on Whole Genome Sequencing (WGS), isolates are part of two distinct but related genetic clusters. ECDC and EFSA are liaising with relevant authorities in the Member States and at the EU level to facilitate the coordination of investigation and response measures. From 1 May 2016 to 12 October 2016, seven EU/EEA countries have reported 112 confirmed cases belonging to two distinct WGS clusters, and 148 probable cases sharing the S. Enteritidis MLVA profiles 2-9-7-3-2 or 2-9-6-3-2. Outbreak cases, both confirmed and probable, have been reported by Belgium, Denmark, Luxembourg, the Netherlands, Norway, Sweden and the United Kingdom. Nine of the confirmed cases are associated with a travel history to Hungary or Poland, both of which countries are also considered to be affected by this outbreak. In addition, Croatia reported a cluster of S. Enteritidis cases, including a fatal case, with an epidemiological link to the outbreak. The characterisation of the Croatian isolates is currently ongoing. The food safety authorities in Belgium, Croatia, the Netherlands and Scotland have carried out extensive environmental and food investigations to identify the source of this outbreak. Since S. Enteritidis is mostly associated with chickens, the investigations focused, among other food items, on the tracing of eggs and chicken meat supply chains into food establishments where outbreak cases had reported eating. As of 25 October 2016, these investigations showed that a number of food establishments and at least a retail chain in Croatia received eggs supplies from packing centre B in Poland. Additionally, the cases in the Croatian cluster had consumed eggs originating from packing centre B in Poland. Additional sampling of eggs intended for direct human consumption originating from the implicated Polish packing centre B was performed in the Netherlands in October 2016 yielding positive results for S. Enteritidis contamination. Eight nonhuman S. Enteritidis isolates from the abovementioned eggs were found to have MLVA type 2-9-7-3-2 and to belong to the two WGS clusters associated with this outbreak. S. Enteritidis isolates from food testing in Norway, sampled in May and November 2015 and identified through a company’s own check controls, were also demonstrated to be part of one of the WGS clusters defining the outbreak. The isolates originated from unpasteurised liquid eggs, which were made from fresh eggs imported to Norway from the Polish packing centre B. The available evidence from WGS, food and environmental investigations, as well as from tracing-back investigation of eggs, establishes a link between this multi-country foodborne outbreak and the packing centre B in Poland, pointing at eggs as the most likely vehicle of infection for at least part of the outbreak cases. Competent authorities in Poland and in the Member States where eggs from the packing centre B were distributed, have already introduced restrictive measures to withdraw and stop placing implicated eggs on the market and investigations are ongoing to eliminate the source.