To update, two clusters of non-O157:H7 E. coli illnesses in Michigan and Ohio share the same genetic pattern and appear to be linked to a common food item.  10 Washtenaw County (MI) residents have suffered culture confirmed E. coli O145 infections, and the health department is awaiting stool test results on another 14.  Meanwhile, at least 5 Columbus, Ohio residents, including students at The Ohio State University, have also been confirmed as positive for E. coli O145, matching the Washtenaw County strain. 

Health officials say they are focusing on an area food distributor.  Laura Bauman, an epidemiologist with Washtenaw County Health, said there is a common link between both collections of reported cases in Washtenaw County and in Ohio and the food distributor they are investigating.

"Department of Agriculture officials are doing a ‘trace-back’ on the food products to determine the origin of the contamination," Bauman said.

When asked whether the contamination most likely occurred in the distribution or the production of the foods, Bauman said they are unable to determine that at this point and they are leaving that aspect of the investigation to the state’s agriculture department investigators.

The good news:  Bauman said it has been a positive sign that they have not found a reported case from somebody outside of that time frame – meaning that, more than likely, the infected food product or products were exposed to E. coli for only a brief period of time.  As for the restaurant or restaurants involved in the outbreak, which have not been identified by health officials, Bauman said they are working closely with them but have not asked owners to stop using any specific distributor. "We don’t have any answers right now. We won’t ask them to take action until we have some more concrete answers," she said.

Multiple clusters of matching illness + regionally distributed food product + relatively confined exposure period (i.e. limited shelf-life) + pathogenic strain of E. coli = lettuce, spinach, or another leafy green?