New virus strain linked to increase in gastroenteritis cases in Hong Kong

New virus strain linked to outbreaks in homes for the elderly, kindergartens and hospitals

PUBLISHED : Friday, 24 August, 2012, 12:00am
UPDATED : Friday, 24 August, 2012, 3:02am

A virus strain new to Hong Kong may be the reason for an abnormal surge of gastroenteritis cases this month.

Outbreaks in places such as homes for the elderly are five times last year's monthly number, while private doctors and public hospitals have seen a three-fold increase.

The Centre for Health Protection says a new strain of norovirus, which causes inflammation of the stomach and small intestine, could be behind the increase.

The centre said it was unusual for the virus to be so active in summer. It expected the peak to last for at least two more months.

"We cannot be sure about the reason for the summer surge, but from what we have seen, there is a new circulating strain of the norovirus which has replaced a previous strain," said centre controller Dr Thomas Tsang Ho-fai. The GII.e strain was previously seen in Europe and most Hong Kong people would not have immunity to it, he said.

An infection causes acute gastroenteritis symptoms - nausea, vomiting, diarrhoea, stomach pain and low-grade fever - but most people recover in a few days.

Crowded institutions such as homes for the elderly, kindergartens and hospitals, with a higher risk of transmission, have reported 55 outbreaks this month alone compared with about 10 in previous summers.

"The virus seems to attack people in all age groups," Tsang said. He urged people to maintain high standards of hygiene and to disinfect areas contaminated with vomit or faeces to stop the virus spreading.

The centre is also keeping an eye on an outbreak of West Nile virus in the US that infected 1,100 people, causing 41 deaths.

Tsang said the risk for Hong Kong was low, as the disease was not transmitted human to human. "It is spread by sick birds to mosquitoes, and the mosquitoes bring it to humans when they bite," he said.