The source of a US outbreak of E. coli O157:H7 infection associated with consumption of Costco rotisserie chicken salad is still under investigation, but preliminary test results indicate the presence of E. coli O157:H7 in diced celery and onion mix used to make the salad in Costco stores.
Tests by the Montana Public Health Laboratory on celery and onion mix samples taken from a Costco store tested positive and further tests are now underway to determine the genetic fingerprint of the isolate and determine whether it is the same as the outbreak strain of E. coli O157:H7.
The evidence to date suggests that a diced celery and onion blend produced by Taylor Farms Pacific Inc., of Tracy, California, could be contaminated with E. coli O157:H7. In response, the company has issued a voluntary recall of multiple products that might contain contaminated celery.
The outbreak has so far affected 19 people in seven states, with five cases requiring hospital treatment and two people developing haemolytic uremic syndrome (HUS). Chicken rotisserie salad has been removed from sale in all Costco stores until further notice.