By Chris Boyette, CNN
(CNN) -- An Ohio doughnut shop has voluntarily closed as public health workers investigate a norovirus outbreak affecting 266 people, according to county health officials.
Mama C's Donuts and Coffee in Maumee, Ohio, a suburb of Toledo, volunteered to shut its doors Tuesday after the Toledo-Lucas County Health Department informed the owners that the restaurant is associated with a Norovirus outbreak investigation, according to a health department statement.
The health department said it had been alerted to reports of several customers who had gotten sick after eating doughnuts from Mama C's between August 4 and August 7. According to Greg Moore, program coordinator with the county health department, "specimens" were sent to the Ohio Department of Health for norovirus testing and three came back positive for the virus.
"Mama C's is being extremely cooperative," the health department said. "The health department has been in contact with the professional cleaning company that Mama C's is using to ensure the food establishment is properly cleaned," the statement says.
Calls to Mama C's Donuts and Coffee were not returned Thursday.
According to Moore, the doughnut shop will remain closed until after the cleaning and after it is reinspected by the health department.
Norovirus causes around 20 million cases of gastrointestinal illness in the United States each year, according to the Centers for Disease Control and Prevention, and it spreads easily in any area of close contact.
The virus causes inflammation in the stomach and intestines, leading to stomach pain, nausea and diarrhea. These symptoms typically last one to three days. Other symptoms include a fever, headache and body aches, according to the CDC.
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