A county health commissioner told Maumee City Council members Monday night that they “may never know” the source of a norovirus outbreak that sickened almost 400 customers of a doughnut shop in suburban Toledo.

It’s been two weeks since the news broke about patrons of Mama C’s Donuts & Coffee becoming ill with the telltale, sudden onset, diarrhea and vomiting associated with norovirus.

As of Monday night, county health officials said the case count was holding steady at 394 people — 325 in Lucas County where Toledo is and 69 in adjacent Wood County.

“We want to figure out the cause, but we may never know,” Lucas County Health Commissioner Eric Zgodzinski told the City Council, according to the Toledo Blade newspaper. “We could surmise, and we’ll probably end up having to do that. But the main thing is we stopped the spread of norovirus from that facility.”

The Centers for Disease Control and Prevention and the city-county health department website both report the most common source of foodborne norovirus infections is foodservice workers. The CDC’s most recent report shows 70 percent of all norovirus outbreaks are caused by infected foodservice workers who go to work while they are contagious.

The Lucas County health commissioner listed a number of factors that could have been the source of the outbreak, including employees handling food without thoroughly washing their hands.

The health department has not yet posted the results of its inspection of Mama C’s on Aug. 9. Neither are reports from follow-up visits posted on the department’s website.

Owners of the doughnut shop in suburban Toledo closed it Aug. 8 when public health officials informed them of illnesses among customers. Zgodzinski has repeatedly praised the shop owners since then, saying they cooperated completely during the outbreak investigation. He said they followed suggestions from the health department on how to clean and sanitize their operation.

The doughnut makers also got high marks from customers — including some who were outbreak victims — who told various media outlets in the area that they didn’t fault the business owners or staff. They pledged to local television, radio and print journalists they would return when the shop reopened.

Many of them did just that on Aug. 14.

Zgodzinski’s department had cleared Mama C’s to reopen on Aug. 10, following sanitizing that included a treatment by a robot, but the owners chose to remain closed.

Nearby St. Luke’s Hospital donated the use of its disinfecting robot to clean the doughnut shop. Using pulsing ultraviolet light, the machine destroys  bacterial and viral cells. Health care facilities generally use such equipment after a patient room is vacated.

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