The Kane County Health Department said Tuesday it is investigating an outbreak of a form of salmonella poisoning, possibly linked to a Portillo’s restaurant in St. Charles.

In approximately the past two weeks, 10 cases of Salmonella ser. Typhimurium with a matching PFGE, or genetic, pattern have been reported In Illinois. This pattern is rare in Illinois. At least two additional cases of S. Typhimurium are pending the PFGE results. Cases in other states have also been identified.

The Kane Health Department said a common potential link is that seven of the people affected reported having eaten at Portillo’s at 3895 E. Main St. in St. Charles during April. No specific food item has been identified to be source of the illness.

The management of Portillo’s is actively cooperating with state and local health officials in the investigation, the Kane department said. The restaurant was sanitized overnight Monday and is having all its food handlers tested for possible infection.