Missouri health officials on Wednesday raised to 36 the total number of people sickened since October 7 in an E. coli outbreak in the St. Louis area. There have been no deaths linked to the outbreak, although several patients have reported severe illnesses, including kidney failure.

State health officials say they continue to search for the source of the food-borne bacteria, and all tests on food items have so far been negative. The U.S. Food and Drug Administration is participating in the investigation but has not issued any recalls in response to the outbreak.