CHP keeps close watch on noroviral gastroenteritis

The Centre for Health protection (CHP) of the Department of Health (DH) today (July 3) reminded members of the public and management of institutions to maintain strict personal and environmental hygiene as its surveillance system indicated that Hong Kong experienced a prolonged norovirus season this year.

The appeal was made in view of the increased number of outbreaks of noroviral gastroenteritis occurring in elderly homes and hospitals in recent months.

Fifty confirmed norovirus outbreaks in elderly homes and 22 in public hospitals affecting 699 and 165 persons have been reported respectively since May. These compared with 19 and seven outbreaks in elderly homes and hospitals respectively and 295 persons in the first four months of this year.

A total of 99 noroviral gastroenteritis outbreaks in institutions, including child care centres and schools, involving 1301 persons have been reported in the first six months of this year. In 2005, there were a total of 42 norovirus outbreaks in institutions, affecting 643 persons.

"Gastroenteritis caused by norovirus is commonly found in Hong Kong all year round but is more active in the winter months.

"Sequencing of norovirus detected in the recent outbreaks showed that the outbreaks were caused by the same norovirus variant which is different from the variants identified in previous years," Head of CHP's Infection Control Branch, Dr Raymond Yung said.

He pointed out that norovirus infection could be transmitted via food or water contaminated with the virus, contact with vomitus or faeces or any objects contaminated by the virus.

"Proper management and adequate disinfection of vomitus and faeces matter is of crucial importance in preventing and controlling the spread of the disease," he added.

Joint visits were conducted by CHP staff to support local infection control team to implement outbreak investigation and infection control measures.

The Hospital Authority's (HA) Central Committee on Infectious Disease convened an ad hoc meeting on June 23, 2006. The revised fact sheet on norovirus was discussed. Major infection control measures were reiterated, it includes

1. Staff with GE symptoms will refrain from work;
2. Enhance environmental cleansing in case of outbreak;
3. Practice scrupulous hand hygiene;
4. Isolate or cohort hospitalized suspected case;
5. Conduct immediate cleansing and disinfection if any soiling contamination; and
6. Apply standard and contact precautions on patient caring.

DH is working closely with the HA and the Social Welfare Department to monitor the situation.

The CHP's Infection Control Branch will also arrange health talks to the staff of HA and residential care homes for the elderly.

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 vomitus or faeces matter;
• wear gloves when disposing of vomitus and faeces and wash their hands afterwards;
• clean and disinfect contaminated areas or items promptly and thoroughly with household bleach diluted at a ratio 1 : 50 (by adding 1 part of household bleach to 49 parts of water);
• maintain good indoor ventilation;
• make sure that food, particularly seafood and shellfish, is cooked thoroughly.

Members of the public can obtain more information on the prevention of viral gastroenteritis from DH's website (http://www.dh.gov.hk) or call the Central Health Education Unit hotline, 2833 0111.

End/Monday, July 3, 2006