An outbreak of Escherichia coli O157:H7 infection in southern Sweden associated with consumption of fermented sausage; aspects of sausage production that increase the risk of contamination

Epidemiol Infect. 2008 Mar;136(3):370-80. doi: 10.1017/S0950268807008473. Epub 2007 Apr 20.


A large outbreak of enterohaemorrhagic Escherichia coli (EHEC) infections occurred in southern Sweden during autumn 2002. A matched case-control study was performed and indicated an association between consumption of fermented sausage and EHEC infection (odds ratio 5.4, P<0.002). Pulsed-field gel electrophoresis analysis identified a strain of E. coli O157:H7 in clinical faecal isolates, which was identical to a strain isolated from sausage samples obtained from households of infected individuals. A combination of microbiological and epidemiological results established a link between sausage consumption and the outbreak in 30 out of a total of 39 investigated cases. Contaminated beef was suspected to be the source of infection. Delayed start of fermentation, lack of heat-treatment and a short curing period in cold temperature were identified as the main factors enabling EHEC survival. EHEC can survive throughout the entire production process of fermented sausage if curing conditions are inadequate.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Cooking
  • Disease Outbreaks*
  • Escherichia coli Infections / epidemiology*
  • Escherichia coli Infections / etiology
  • Escherichia coli O157 / isolation & purification*
  • Escherichia coli O157 / pathogenicity
  • Feces / microbiology
  • Female
  • Fermentation
  • Food Microbiology*
  • Humans
  • Male
  • Meat / microbiology
  • Middle Aged
  • Risk Factors
  • Surveys and Questionnaires
  • Sweden / epidemiology