The Department of Health is investigating another gastroenteritis case. The latest involves seven children from Greenfield Kindergarten, Sheung Shui. Tests so far show it could be an outbreak of rotavirus.

Both students and staff are under medical surveillance. The kindergarten will carry out proper disinfection.

Rotavirus is a relatively common cause of gastroenteritis and diarrhoea among children worldwide.

The illness causes vomiting, diarrhoea, fever and abdominal pain. The disease will usually subside on its own but young children are more prone to dehydration.

Mode of transmission is predominantly fecal-oral, but is also possible through ingestion of contaminated water or food and contact with a contaminated surface.

The department received reports of three rotavirus outbreaks in institutions in 2001, five last year, and four this year including the present one.

The department is closely monitoring the recent Norwalk-like virus outbreaks. The hotline 2961 8966 has received 179 calls for information on the disease and preventive measures.

Evergreen Home in Central & Western District has been removed from the list of institutions suspected to have Norwalk-like virus as tests on three residents have given negative results.

Details on the other institutional outbreaks previously reported are:

* Sacred Heart Canossian School in Caine Road (280 students);

* Development Disability Unit at Caritas Medical Centre in Sham Shui Po (17 children and six staff);

* Society for the Protection of Children Sze Wu Shu Min Day Nursery in Tseung Kwan O (27 children);

* Quarry Bay Primary School (58 students); and,

* Ward 7C in Prince of Wales Hospital (Paediatric Orthopaedic Ward) (six patients).

Test results are still pending for:

* King's College Old Boys Association Primary School in Central & Western (five students);

* Kellett School in Southern District (eight students); and,

* Pokfulam Skill Centre in Southern District (six students).

The department is closely monitoring the situation in these institutions. An institution will be removed from the list when its outbreak is over.

To prevent the spread of viral gastroenteritis, the public should observe the following precautions:

* wash hands thoroughly before handling food and eating and after using the toilet or handling vomit or fecal matter;

* wear gloves when disposing of vomit and faeces and wash hands afterwards;

* clean and disinfect contaminated areas and items promptly and thoroughly with household bleach diluted in a ratio of 1 to 49 units of water;

* maintain good indoor ventilation; and,

* make sure that food, particularly seafood and shellfish, is cooked thoroughly.

Students suffering from viral gastroenteritis should stay home until they recover.

The department also reminded institutions to watch out for symptoms of viral gastroenteritis and report any suspected outbreaks.