A stomach illness that sickened more than 30 people has been traced to a Chuck E. Cheese’s restaurant in Woodbury.

The sickness was spread to people who were at the restaurant on Saturday, according to the Washington County Health Department.

Symptoms include vomiting and diarrhea, said Jean Streetar, public health program manager for the county.

One customer initially reported the illness to the state Department of Health, which turned the investigation over to the county Monday, she said.

County investigators working with a restaurant reservation list as of Wednesday had contacted 60 people who might have had contact with the virus; at least 30 of those had been ill.

None of the reported illnesses resulted in trips to the hospital. Symptoms usually develop about 12 hours after exposure.

The illness, called the norovirus, is not the flu, Streetar said. It is not spread through coughing and contact with saliva, but through contact with vomit or feces, she said.

Streetar said that it’s very contagious and that hand-washing is critical for anyone caring for a sick person.

Norovirus is a common cause of stomach ailments.

“These outbreaks crop up all over the place,” Streetar said. But the Chuck E. Cheese’s outbreak is the first one she knows of this winter.

On Wednesday afternoon, a person answering the phone at the Woodbury restaurant would not answer questions about the outbreak, and a phone message left at the corporate office was not returned.

Streetar said the restaurant was not closed by the outbreak but went through a “thorough cleaning.”

Bob Shaw can be reached at 651-228-5433. Follow him at twitter.com/BshawPP.