Risk assessment of E. coli in the Norwegian meat chain

E. coli is part of the normal gastrointestinal microbial flora of humans and animals. E. coli bacteria causing enteric/diarrheal disease are categorized into different groups based on their virulence properties and pathogenic features in humans.

Enterohaemorrhagic E. coli (EHEC) are E. coli strains that cause bloody diarrhoea and haemolytic uraemic syndrome (HUS) in humans, and have a defined zoonotic association.

This risk assessment was conducted after a human outbreak of STEC O103 in 2006, associated with contaminated dry-fermented sausages. The panel on biological hazards appointed an ad hoc working group to draft a risk assessment for further treatment in the panel.

The members of the ad hoc group were: Eystein Skjerve (chair), Hans Blom, Viggo Hasseltvedt, Jørgen Lassen, Truls Nesbakken, Karin Nygård, Anne-Margrete Urdahl.

The current report approaches the task by following and analysing the entire process, from the origin of the meats at farm level, to the final production and storage of dry-cured sausages.

Some of the main conclusions are

• It is not possible to give any reliable quantitative estimates of the current risk associated with consumption of dry-cured sausages.
• The combination of proper slaughter hygiene and use of thermal decontamination of sheep, cattle and pig carcasses represents an efficient way to reduce STEC contamination.
• Proper use of starter cultures in fermentation, combined with higher fermentation temperatures, will reduce the probability of growth of STEC in contaminated dry- cured sausages. A combination of higher fermentation temperatures, a lower pH during the process, and heat-treatment of the final product should effectively eliminate the potential risk for transmission of STEC infections from consumption of dry-cured sausages.
• Technological options are available to reduce significantly the transfer of potential pathogens through meats in general, and specifically through dry-cured sausages.

The panel on biological hazards adopted the risk assessment.