Foodborne outbreaks

The Food and Feed Microbiology Research Unit provides guidance for food laboratories and serves as their supporting and reference laboratory during investigations into foodborne outbreaks. Conventional microbiological analyses related to foodborne outbreaks are conducted in authorised food laboratories and only in particular cases by the Food and Feed Microbiology Research Unit at Evira.

Evira is responsible for more thorough investigations, typing and monitoring of causative agents of foodborne outbreaks isolated from food, from the production environment in food premises and from primary production sites (Ministry of Social Affairs and Health, Decree 1365/2011). The Food and Feed Microbiology Research Unit maintains and develops methods for the extended investigation of major food-poisoning bacteria. Extended investigations encompass biochemical identification, toxin analysis as well as serotyping and genotyping.

Extended investigations of foodborne outbreaks

Food laboratories deliver pathogenic bacterial strains isolated during outbreak investigations to the Food and Feed Microbiology Research Unit for further investigation. Such extended investigations include species identification, serotyping, toxin analysis and molecular biological studies. The Food and Feed Microbiology Research Unit also investigates rare food-poisoning bacteria when local laboratories do not have methodology for investigations. In addition, to define the infective dose, the section performs quantitative studies on certain pathogenic bacteria detected at local laboratories with the enrichment method and suspected of having caused foodborne outbreaks. Investigations relating to foodborne outbreaks are free of charge.

During investigations of foodborne outbreaks, local authorities collaborate with Evira and the National Institute for Health and Welfare (THL). Evira and THL have harmonised their respective PFGE typing methods for Escherichia coli O157 and Listeria monocytogenes, Yersinia enterocolitica, Y. pseudotuberculosis and Streptococcus equi ssp. zooepidemicus and for thermophilic Campylobacter species. This enables comparisons between bacterial strains isolated from patients and suspected sources during outbreak investigations.