Health officials reported that they have identified the source of an E.Coli outbreak in Costco stores in Washington State. According to a report from the Washington Post, investigators have traced the outbreak to a vegetable mix that was used in the store’s chicken salad to 19 confirmed illnesses in seven different states.

The outbreak was linked to Taylor Farms Pacific Inc. from Tracy, CA. The store has recalled all chicken salad on its shelves that used a blend of chopped onions and celery believed to be infected with E.Coli. The FDA urged for the recall of all other products containing celery from Taylor Farms out of “an abundance of caution.”

Foods affected by the E.Coli outbreak include Thai-style salads, packaged dinners and sandwich wraps. The problem may not be limited to Costco too; investigators say that Taylor’s produce was also sold in Target, Starbucks, and a number of other outlets.

According to Costco, based in Issaquah, WA, the company only uses one supplier for the vegetables in its chicken salad sold in stores throughout the entire country. The company posted notices in its stores and provided information to the U.S. Centers for Disease Control and Prevention to try and find exactly where the outbreak originated.

A press release from the Washington State Department of Health regarding the outbreak can be found here.