The number of cases of norovirus infection, known to cause severe vomiting and diarrhea, has risen sharply among children in the past few weeks, with several schools reporting clusters and health experts stressing the significance of maintaining hand hygiene to contain the disease transmission.

A school covering grades 1 to 12 in Wenzhou, Zhejiang province, said in a notice released on Sunday that it was hit by a norovirus outbreak, following confirmation from disease control officials.

The school suspended classes that have infected children, though their cases are mild and they are in stable condition. The school did not reveal the number of infections.

Local media said that 11 students from three junior high level classes were found to have been vomiting, citing the local education bureau. Since last month, kindergartens and schools in the provinces of Shaanxi, Yunnan and Hubei have registered norovirus outbreaks.

A kindergarten in Xi'an, Shaanxi province, reported at least 48 toddlers were infected around mid-October.

Peng Zhibin, a researcher at the Chinese Center for Disease Control and Prevention, said that norovirus is the most common cause of acute inflammation of the stomach or intestines.

The disease can spread all year round but enters its peak season from October to March.

"The norovirus is highly contagious and capable of spreading through contact with food, water and any surfaces or objects contaminated with the virus, or with feces or vomit of infected individuals," she said during a news conference last week.

Peng said that the most typical symptom among children is vomiting, while adults tend to experience diarrhea. Sickness, abdomen pain, fever and muscle soreness are also common symptoms.

She added that most people recover from infections in a couple of days, and there is no need for special treatment except for staying hydrated and maintaining personal hygiene. However, infants and seniors who are at high risk of dehydration due to the disease need special attention.

To prevent the disease, Peng said that first and foremost, it is important for people to keep their hands clean by washing with soap and running water before making or eating food and after using the restroom.

"People who have the virus should also avoid contact with other people while showing symptoms and within two to three days after symptoms disappear to avoid spreading the virus to others," she added.

wangxiaoyu@chinadaily.com.cn