The Kansas Department of Health and Environment is currently conducting an outbreak investigation of Shiga toxin-producing Escherichia coli (STEC) O157:H7 cases among persons who attended the Louisburg Cider Mill Ciderfest, which was held September 24-25 and October 1-2. To date, there are seven laboratory-confirmed cases associated with this investigation. However, this investigation is ongoing and information is subject to change. The Kansas Department of Agriculture along with the U.S. Food and Drug Administration and KDHE performed an on-site assessment on October 27.