Press Release

Norwalk-like virus implicated in primary school gastroenteritis outbreak

November 14, 2003

The Department of Health (DH) is investigating a gastroenteritis outbreak which affected some 150 students of a primary school.

DH staff visited the school in Central and Western District today (November 14) and yesterday. Investigations revealed that the sick students suffered from vomiting, diahorrea and abdominal pain. Two of them are admitted to hospital in stable condition, while the others are having rest at home.

The school has been under DH's medical surveillance. DH is contacting the students and parents to ascertain their symptoms and collect stool samples. A stool sample from a sick student is tested positive for Norwalk-like-virus this afternoon.

"Viral gastroenteritis caused by Norwalk-like-virus is usually self-limiting with symptoms of nausea, vomiting, diarrhea, abdominal pain, low-grade fever and malaise. The symptoms usually last for 24 to 48 hours. Viral gastroenteritis is more common in winter months. In 2002, there were nine reported outbreaks of Norwalk-like-virus-related viral gastroenteritis in primary schools, affecting more than 300 students."

"On an on-going basis, DH issued Guidelines on Prevention of Communicable Diseases to all child care centres, kindergartens, schools and relevant institutions. Following the gastroenteritis outbreak, DH staff provided the school concerned with health advice on viral gastroenteritis and the proper disinfection procedures. The school management carried out thorough disinfection in the premises today and tomorrow under the supervision of DH. All schools were also reminded of the precautionary measures to take in preventing viral gastroenteritis in institutional settings."

The spokesman said the infection can be transmitted via food or water contaminated with the virus, contact with vomitus or faeces from infected persons contaminated objects, and by aerosol spread.

To prevent viral gastroenteritis, members of the public are advised to:

• wash hands thoroughly before handling food and eating and after going to toilets and handling vomitus or faecal matter:
• wear gloves while disposing of vomitus and faeces, and wash hands afterwards;
• clean and disinfect contaminated area and items promptly and thoroughly with household bleach diluted in a ratio 1 in 49 units of water
• sick students should rest at home and not go to school;
• maintain good indoor ventilation;
• eat only thoroughly cooked food particularly seafood and shellfish.

With the approach of the high season for viral gastroenteritis, DH is reminding schools to watch out for students with symptoms of viral gastroenteritis and report to DH if an outbreak is suspected.

Members of the public can obtain health advice on the prevention of the viral gastroenteritis at DH's website (This link will open in a new windowhttp://www.dh.gov.hk), or by calling DH's Central Health Education Unit hotline at 2833 0111.