Grocery store loyalty cards played a key role in tracing a Salmonella outbreak in the Pacific Northwest to chicken from California-based poultry producer Foster Farms.
The outbreak, from June 2012 to April 2013, sickened 134 people in 13 states. Using pulsed-field gel electrophoresis testing, public health investigators in Oregon and Washington determined that the strain of Salmonella enterica serotype Heidelberg they identified was the same as the strain linked with Foster Farms chicken in a 2004 Salmonella outbreak.
New Tool in Epidemiology. JAMA. 2013;310(9):896. doi:10.1001/jama.2013.254324