An outbreak of shiga toxin-producing E. coli in Danish
children was traced back to beef sausages using an unusual
epidemiological tool: credit card receipts. The case is described in
the April 15, 2009 issue of Clinical Infectious Diseases, now available online.
Between February and May of 2007, Danish officials identified 20 genetically related cases of E. coli
infection. All cases were relatively mild, and the patients recovered.
Interviews with the parents of the sick children didn’t turn up any
likely food suspects, so investigators had to try something different. Armed with the parents’ credit card information and a list of
supermarkets at which they had shopped, the authors asked the grocery
stores to search their central computers for a list of all items
purchased by the affected families.
Complete lists of items
purchased were obtained for seven families, five of which had purchased a
particular brand of fermented, organic beef sausage. A sixth family
was linked to the sausage through shopping records from the kindergarten
their two affected children attended. Sausages recovered from unopened
packages tested positive for the outbreak strain, STEC O26.
The
authors say the source of the outbreak would most likely never have been
found without credit card and supermarket database information. This
is also the first time the outbreak source of the less common E. coli
strain O26 has been identified. If diagnostic efforts and quality
control programs in food production are focused only on detecting the
more common STEC O157 strain, the authors caution, more outbreaks and
illnesses are possible.
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