Beijing reported 166 cases of norovirus in the first quarter of this year, and the outbreak is likely to last till June, said local health authorities on Wednesday.
Of the 166 cases, 82 were in kindergartens, 69 in primary schools, nine in middle schools, four in colleges, one in a restaurant and one at home.
"The epidemic is serious this year and we see many variants of the virus," said Pang Xinghuo, deputy director of the Beijing Center for Disease Prevention and Control (CDC).
Norovirus, a form of food-poisoning, is one of the major gastrointestinal viruses. Symptoms include nausea, diarrhea, vomiting and abdominal cramps and usually appear within 12 to 72 hours of exposure, typically lasting for two or three days.
CDC warned that kindergartens and schools be disinfected and the health of students closely monitored as new cases emerge.