In 2013 and 2014 local, state, and federal public health and agriculture agencies collaborated in a multistate outbreak of Salmonella Heidelberg. Investigators used PulseNet to identify patients who were considered outbreak associated cases. Epidemiologic, laboratory and traceback investigations indicated that consumption of Foster Farms brand chicken was the source of the outbreak. Seven strains of Salmonella Heidelberg were isolated in patients. Before this outbreak, four of these strains were rarely reported to PulseNet. The other three strains were more common, with several ill persons infected with each strain reported to the CDC monthly. The DNA fingerprints of the Salmonella Heidelberg bacteria associated with this outbreak include the strain that was also associated with a multistate outbreak of Salmonella Heidelberg linked to Foster Farms brand chicken processed at an establishment in Washington State during 2012-2013.
A total of 634 persons infected with the outbreak strains of Salmonella Heidelberg were reported from 29 states and Puerto Rico from March 1, 2013 to July 11, 2014. Most of the ill persons (77%) were reported from California. Among 528 persons for whom information was available, 200 (38%) were hospitalized. Fifteen percent of ill persons developed blood infections as a result of their illness. No deaths were reported.
In interviews, 74% of ill persons reported consuming chicken prepared at home in the week before becoming ill. Among those who had brand information, 187 (87%) of 175 ill persons reported they consumed Foster Farms brand or another brand likely produced by Foster Farms. Health departments in Washington and California collected leftover chicken from the homes of ill persons for laboratory testing. Salmonella was isolated in leftover chicken, in an unopened package of raw Foster Farms chicken, and in leftover rotisserie chicken.
During September 2013, USDA-FSIS conducted in-facility testing for Salmonella at four Foster Farms production establishments in California and Washington. Six of the seven outbreak strains of Salmonella Heidelberg were isolated from raw chicken samples collected from the three Foster Farms establishments in California. At that time FSIS threatened Foster Farms with removing inspectors because sanitary conditions at its three facilities were so poor that they posed a “serious ongoing threat to public health.” FSIS officials had found a “high frequency of Salmonella Heidelberg positives and specifically a high frequency of one or more outbreak strains” in the three plants. The letters also cited “fecal material on carcasses” and “findings of poor sanitary dressing practices, insanitary food contact surfaces, insanitary non food contact surfaces and direct product contamination” at the plants. See Notices of Intended Enforcement: ONE, TWO and THREE that FSIS sent to Foster Farms.
On July 3, 2014 Foster Farms recalled an undetermined amount of chicken products due to contamination with Salmonella Heidelberg. The recall resulted from USDA-FSIS identifying one of the outbreak strains of Salmonella Heidelberg in an intact sample of Foster Farms brand chicken collected from the home of a person in California infected with the same strain. The chicken breasts were packaged with critical labeling information to associate the product with the establishment and a specific production date.
By July 31, 2014 the CDC declared the outbreak to be over as the number of reported infections had returned to the expected number for that time of year.