ecoli-bacteriaThe Whatcom County Health Department (WCHD) is investigating an outbreak of shiga toxin – producing E. coli O157 associated with the Milk Makers Fest that was held at the Northwest Fairgrounds in Lynden on 4/21 –4/23/15.

WCHD is continuing to interview cases to determine if there was a common food or water source or activity, such as the petting zoo or other contact with livestock.

Washington State Department of Health Communicable Disease Epidemiology is assisting with the outbreak investigation. Cumulative total: 18 cases* (5 cases have been hospitalized), 18 probable cases ** Change since last report 4/30/15: +1 case, +3 probable cases, 1 new hospitalization.

*Cases include those with positive labs (preliminary presumptive positive O157 and final confirmed positives), and clinical cases with close contact with a case with positive or presumptive positive labs.

** Probable cases are cases with clinical symptoms and were associated with the event, but lab results are not available or labs were not done.

Clarification from previous reports: the state public health lab is testing confirmed E. coli O157 isolates for serogroup (to determine if O157:H7 or another related serogroup).

Preliminary positive O157 isolates are regrown and have further testing done at a commercial lab to confirm O157. We expect to get the first results of serogroup testing from the state public health lab early next week.