JEFFERSON TWP — South Butler County School District officials responded this week to a believed norovirus outbreak at the primary school.

Noroviruses are a group of viruses that cause gastroenteritis, which is often called the “stomach flu,” according to the state Department of Health.

Symptoms from noroviruses typically last one or two days.

In a letter sent home to parents of primary school students Thursday, Superintendent David Zupsic wrote that the school for two days had experienced an abnormally high number of students suffering from the symptoms of stomach flu.

Friday was a teacher in-service day and Monday is a vacation/snow day, so students are not scheduled to return to school until Tuesday.

While the students are out of the building, the district planned a cleaning effort that involved “thoroughly cleaning and disinfecting classrooms, restrooms, cafeteria and other areas of the building. High-touch areas will be a focus of the process,” according to the letter.

Parents were asked to keep their children home from school if they are sick Tuesday.

Students in kindergarten through third grade attend the primary school, located on Knoch Road.