The outbreak of E. coli O157:H7 linked to Costco Rotisserie Chicken Salad appears to be over. According to the final report from the Centers for Disease Control and Prevention, 19 people across seven states were sickened. The most recent illness in this outbreak reported to CDC started on November 3, 2015. Most illnesses were reported from the western United States. Five ill people were hospitalized, and two developed hemolytic uremic syndrome, a type of kidney failure. No deaths were reported. The epidemiologic evidence collected during this investigation suggested that rotisserie chicken salad made and sold in Costco Wholesale stores in several states was the likely source of this outbreak. Fourteen (88%) of 16 people purchased or ate rotisserie chicken salad from Costco in the week before illness started. On Nov. 20, Costco reported to public health officials that the company had voluntarily removed all remaining rotisserie chicken salad from all stores in the United States. Preliminary testing of a sample of diced celery and onion blend collected from a Costco location by the Montana Public Health Laboratory indicated the presence of E. coli O157:H7. The blend was used to make the rotisserie chicken salad eaten by outbreak victims. It was supplied by Taylor Farms Pacific, voluntarily recalled the celery and onion diced blend and many other products containing celery from retailers such as Costco, Starbucks and Target. However, an investigation update provided by the U.S. Centers for Disease Control and Prevention (CDC) on Dec. 8 stated that further laboratory analysis was unable to confirm the presence of E. coli O157:H7 in the sample of diced celery and onion blend. The FDA conducted a traceback investigation of the FDA regulated ingredients used in the chicken salad to try to determine which ingredient was linked to illness, but could not identify a common source of contamination. (To sign up for a free subscription to Food Safety News, click here.)