Shiga toxin-producing Escherichia coli (STEC) O157 outbreak, The Netherlands, September - October 2005

Area of Science:

• Foodborne Illness Epidemiology
• Microbiology
• Public Health

Background:

• The Netherlands experienced its first national food-related outbreak of Shiga toxin-producing Escherichia coli (STEC) O157 in September 2005.
• The outbreak affected 21 laboratory-confirmed and 11 probable cases, with illness onset between September 11 and October 10, 2005.

Purpose of the Study:

• To investigate the cause of the national STEC O157 outbreak in the Netherlands.
• To identify the food vehicle and risk factors associated with the outbreak.

Main Methods:

• A case-control study was conducted to assess potential risk factors.
• Epidemiological data was collected on confirmed and probable cases.
• Food samples were collected and tested for STEC O157.

Main Results:

• Steak tartare consumption was strongly associated with STEC O157 infection (matched OR 272).
• Consumption of ready-to-eat vegetables was also associated but considered a less likely source.
• STEC O157 was not detected in steak tartare samples, likely due to delayed sampling after the outbreak period.

Conclusions:

• Steak tartare was identified as the most probable source of the 2005 national STEC O157 outbreak in the Netherlands.
• Point source contamination is a plausible explanation for the negative food sample results.
• This outbreak highlights the risk associated with raw meat consumption.