INFOSAN in action to prevent cases of Listeriosis caused by contaminated frozen vegetables

Since 2015, an outbreak of invasive Listeriosis, caused by the bacteria Listeria monocytogenes, has been ongoing in five European countries, resulting in 47 cases over a multi-year period. This outbreak has been linked by whole genome sequencing (WGS) to frozen corn and possibly other frozen vegetables processed at a single plant in Hungary. Since this outbreak was identified, one case of listeriosis was reported outside of Europe, in Australia, that was found to be highly related to the current outbreak strain.

A recall of all frozen vegetable products produced since August 2016 at the implicated factory has been ongoing since the end of June 2018. Recalled products have been exported to more than 100 countries. In some countries, products have been re-exported or further processed into other products making traceability efforts increasingly challenging and complex. 

The INFOSAN Secretariat has worked in collaboration with the European Rapid Alert System for Food and Feed (RASFF) as well as with INFOSAN members in the exporting countries to identify and share export details with recipient countries. The rapid exchange of information between INFOSAN members and the INFOSAN Secretariat helps to facilitate local recalls, provide public health advice to consumers and implement other risk management measures to reduce the risk of exposure to the implicated products around the world. 

Due to the long shelf-life of these frozen products (some until mid-2020) and the long incubation period of listeriosis (on average 1-3 weeks but possibly up to 70 days), the risk to consumers will remain for some time and additional cases could be detected in the coming days and weeks. 

The INFOSAN Secretariat will continue to work closely with INFOSAN members to monitor the international distribution of these products and provide technical assistance as required to ensure efficient recalls and the prevention of further cases. 

This outbreak serves as a reminder to consumers that frozen raw vegetables should be cooked or heat-treated properly before consumption. 

The INFOSAN Secretariat advises all consumers to follow the WHO Five Keys to Safer Food which includes simple recommendations on how to safely handle and prepare food at home. The recommendations in the form of a poster are available in 87 different languages.