Ten cases of E. coli have been identified among customers who ate hamburgers at various Red Cow restaurants, and one case was found at Hen House Eatery in downtown Minneapolis, the Minnesota Department of Health said Friday.

The ground beef connected to those infections was also distributed to other unidentified establishments, according to the Health Department. Potential cases were under investigation.

Red Cow has three locations in Minneapolis along with restaurants in St. Paul, Wayzata and Rochester.

The confirmed cases involve meals purchased from Oct. 31 through Nov. 7, and illnesses began Nov. 4-9, according to the department. Those affected range in age from 9 to 70 years; two people were hospitalized.

Red Cow and Hen House Eatery owners were fully cooperating with the investigation and have already made product changes to prevent further illness, the department said.

Red Cow management issued a statement Friday saying they had taken immediate action to stop serving the ground beef and to disinfect and sanitize its restaurants, all of which have since passed health inspections.

Because the issue was product-related, none of the restaurants were forced to close. According to Red Cow, approximately 61 other restaurants purchased the ground beef, processed by Wolverine Packing Co. and sourced through US Foods.

Symptoms of the O157 strain of E. coli typically include stomach cramps and diarrhea, often with bloody stools. Illness can set in anywhere from one to eight days after exposure. About 5% of cases can lead to severe complications such as acute kidney failure.

About 100 cases of E. coli O157 are reported annually in Minnesota, according to the Health Department. More information can be found on the department's E. coli website.