Norovirus outbreak involving over 100 students at the Ann Arbor campus of the University of Michigan has been confirmed by health officials. Authorities from the Michigan Department of Health and Human Services report cases as early as Monday at the West and South Quad dorms.

Tests conducted by the health department confirmed that it was a case of Norovirus. However, the cause of the outbreak is still to be determined.

Norovirus-infected students all consumed food given out by the South Quad cafeteria. They all exhibited symptoms including vomiting, diarrhea and other digestive system related problems. Sick students are encouraged to stay in their rooms to thwart the spread of the disease.

The University of Michigan residents were recommended to wash their hands frequently as a precautionary measure. Other health advice include disinfecting dirty surfaces and handheld objects such as mobile phones, avoiding food and drinks sharing, and preventing close contact with those who are infected, CBS Local reported.

Meanwhile, the administration is conducting a university-wide cleaning procedure, paying close attention to the facilities’ dining halls. Even neighboring residential properties participated in the cleanup.

Seattle health officials investigated a Norovirus outbreak at a Maggiano’s Little Italy restaurant in January. The outbreak affected nearly 50 attendees at a private. Popular food chain Chipotle also faced an E. coli outbreak in November 2015; 53 people were hospitalized. Norovirus outbreak also affected over 140 Boston College students after having lunch at  Cleveland Circle.

Food-borne disease cases reach about 600 million each year, leading to 420,000 deaths worldwide. One in 10 people every year become ill because of what they eat or drink, Business Insider reported. Norovirus, specifically, spreads rapidly. It can be transmitted through food and drinks and using contaminated surfaces or objects. On average, Americans are infected with the virus, at least, five times over their lifetime.

Norovirus virus peaks from November to April each year.