Timeline of Events
Multistate Outbreak of Multidrug-Resistant Salmonella Heidelberg Infections Linked to Foster Farms Brand Chicken (Final Update)
Posted July 31, 2014 4:00 PM ET
This outbreak appears to be over. However, Salmonella is an important cause of human illness in the United States. More information about Salmonella, and steps people can take to reduce their risk of infection, can be found on the CDC Salmonella Web Page.
June 17, 2013: PulseNet reports a cluster of illnesses on the West Coast, primarily California, with a single rare PFGE pattern of Salmonella Heidelberg (PFGE Pattern #1) to the Outbreak Response Team at CDC. PulseNet identifies a non-human retail chicken isolate from the National Antimicrobial Resistance Monitoring System (NARMS) retail meat surveillance program with PFGE Pattern #1.
June 28, 2013: USDA-FSIS is notified by CDC of its multistate investigation of PFGE Pattern #1.
July 1, 2013: USDA-FSIS notifies CDC that the NARMS retail chicken isolate with PFGE Pattern #1 was Foster Farms brand chicken. PulseNet identifies a second cluster of illnesses with another rare PFGE pattern of Salmonella Heidelberg (PFGE Pattern #2).
July 3, 2013: CDC hosts the first multistate conference call for the first cluster, PFGE Pattern #1.
July 5, 2013: USDA-FSIS conference call with Foster Farms to provide a summary of the investigation to date.
July 8, 2013: PulseNet identifies a third cluster of illnesses with a common PFGE pattern of Salmonella Heidelberg (PFGE Pattern #3).
July 12, 2013: Washington State identifies a fourth cluster of a very rare PFGE pattern of Salmonella Heidelberg (PFGE Pattern #4). An additional PFGE pattern, PFGE Pattern #5, was also identified based on similar epidemiologic data.
July 18, 2013: Working with California, CDC combines PFGE Patterns #1-5 into a single investigation due to some of the patterns being similar and a high proportion of ill persons reporting that they had consumed Foster Farms brand chicken.
July 22, 2013: USDA-FSIS begins working with California public health officials to obtain shopper histories for product traceback.
July 29, 2013: CDC begins investigating two additional Salmonella Heidelberg PFGE patterns (PFGE Patterns #6 and 7) due to high proportion of ill persons reporting chicken consumption and similar demographics and geographic distribution.
July 30, 2013: Outbreak Response Team receives antimicrobial susceptibility testing results from the CDC NARMS laboratory for 4 human isolates matching PFGE Patterns #1 and #2. Resistance to several commonly used antibiotics was identified.
August 6, 2013: Intact leftover product from ill person’s home in Washington State tests positive for PFGE Pattern #4. Product traces back to Foster Farms.
August 9, 2013: First joint USDA-FSIS/CDC conference call with Foster Farms to inform the firm about the outbreak and the link to Foster Farms brand chicken.
August 21, 2013: USDA-FSIS begins internal meetings on proposed epidemiologically based intensified sampling at four Foster Farms establishments identified during traceback.
September 4, 2013: USDA-FSIS finalizes its intensified sampling plan focusing on post-chilled product undergoing additional handling within the establishment implicated in illnesses.
September 9 – 27, 2013: USDA-FSIS conducts onsite investigation at four establishments. Intensified Salmonella testing conducted during the investigation.
September 24 – 25, 2013: Preliminary intensified Salmonella sampling results shared with CDC.
September 30, 2013: Cluster of Salmonella Heidelberg illnesses identified in South San Francisco linked to rotisserie chicken sold at a single Costco store location. Two samples of leftover rotisserie chicken collected from ill persons for testing.
October 7, 2013: USDA-FSIS issues “Notice of Intended Enforcement” to Foster Farms and releases a “Public Health Alert” urging consumers to handle chicken safely.
October 8, 2013: CDC posts first outbreak investigation web announcement.
October 10, 2013: Outbreak Response Team receives antimicrobial susceptibility testing results from the CDC NARMS laboratory for 5 additional human isolates matching PFGE Patterns #2 and #4. Resistance to several commonly used antibiotics was identified.
October 11, 2013: Laboratory results identified PFGE pattern #1 in both samples of leftover cooked rotisserie chicken sold at the single Costco store location.
October 12 and October 17, 2013: FSIS announces the recall of more than 23,000 units of cooked rotisserie chicken products sold at the single Costco store location due to potential cross-contamination after cooking.