CHICAGO, June 6 (Xinhua) -- At least 60 adults and children were sickened after attending a disabled children's event in the U.S. state of Wisconsin, local media reported on Tuesday.
"Laboratory testing identified Norovirus as the cause of the infection," the Leader-Telegram quoted Wisconsin public health official Jennifer Miller as saying.
However, the source of the outbreak remained under investigation, she added.
Nine local health departments were working now to determine the specific source which led to the outbreak of gastroenteritis following the two-day event.
According to the organizers of Special Kids Day, 738 disabled students were among the 1,000 people attending the annual festival at the Northern Wisconsin State Fairgrounds in Chippewa Falls.
Norovirus can cause viral gastroenteritis in humans. It is transmitted by contaminated food or water, by person-to-person contact. People infected by Norovirus usually suffer nausea, vomiting, and diarrhea.