A multi-country foodborne outbreak has been ongoing in Europe for 3 years.
Eggs have been linked to a Salmonella Enteritidis outbreak in the EU from February 2017 through January 2020. A total of 15 countries have reported 656 confirmed cases and 202 probable cases. Before February 2017, 385 historical-confirmed cases and 413 probable-historical cases were identified, making the total number of countries affected 18.
The European Centre for Disease Prevention and Control (ECDC) says that, due to differences in capacity for case information, more countries are likely to have been affected.
According to ECDC, the outbreak appeared to peak during the summer months of 2016, 2017, and 2018. However, a notable decrease in the frequency of cases reported to the agency was observed in 2019, which was a deviation from the previous 3 years of the outbreak.
An epidemiological and microbiological traceback investigation have linked the pre-2018 cases to egg consumption—specifically eggs from laying hen farms of a Polish consortium. A national investigation in 2018 in the UK identified epidemiological links between some cases and consumption of table eggs or egg products, with traceability possibly pointing to the Polish consortium.
Even though control measures were put in place in 2016 and 2017, the Polish consortium farms tested postive for the outbreak strains in 2018 and 2019, suggesting the persistence of contamination. Investigations focusing on the laying hen production and feed supply chains did not reveal any significant insights on the possible origin of the contamination.
One of the outbreak strains was found between 2017–2019 in primary production in Germany.
The multi-country outbreak is still ongoing. ECDC says that since they have no proof that the source of contamination has been eliminated, additional infections and new cases are likely to occur in the coming months. Still, they expect additional investigating to uncover the contamination source.