Public reminded to maintain vigilance against gastroenteritis associated with norovirus

7 Jan 2010

The Centre for Health Protection (CHP) of the Department of Health (DH) today (January 7) reminded members of the public and management of institutions to step up personal and environmental hygiene in the wake of recent outbreaks of gastroenteritis associated with norovirus in institutions.

A CHP spokesman said that in the past three months (October to December 2009), there were 78 confirmed norovirus outbreaks reported in institutions affecting a total of 908 persons.

The figures were higher than those reported in the corresponding periods of the past three years- 57 outbreaks in 2006, 22 in 2007 and 16 in 2008.

Our various sentinel surveillance systems also recorded recent increases in vomiting and diarrhoeal activities. Besides, the Public Health Laboratory Service Branch of CHP has detected a new recombinant 2006-2008 strain of norovirus, which has also been detected in other countries in 2009.

However, there is so far no evidence that these genetic changes are associated with more severe illness.

Norovirus is known to have genetic changes from time to time at about two to three years intervals. In Hong Kong, new strains of norovirus have also been detected previously in year 2002, 2004 and 2006.

The spokesman said, "Gastroenteritis caused by norovirus is commonly found in Hong Kong all year round although it is more active in the winter months. Norovirus infection can be transmitted via food or water contaminated with the virus, or contact with vomitus or faeces or any objects contaminated by the virus. The symptoms are usually self-limiting and patients usually recover within three days.

The CHP has issued letters to healthcare professionals and various institutions in November last year to alert them about the seasonal rise in norovirus activities and to provide health advice.

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

To prevent the spread of viral gastroenteritis, the public should take 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 CHP's website (www.chp.gov.hk) or call the Central Health Education Unit hotline, 2833 0111.