Only in the worst-case scenario and on the World Health Organization's recommendations would Hong Kong consider closing its borders, Hong Kong Secretary for Health, Welfare & Food York Chow said on Wednesday.

Speaking in reply to a lawmaker's question at a Legislative Council meeting, Chow said when there is evidence showing effective person-to-person transmission of a new strain of the avian influenza virus, Hong Kong would first step up its health measures at the immigration control points.

Chow said these include asking inbound travelers to declare their health status or placing those who may have been infected under quarantine.

"The government has the obligation to take care of its people. To stop the spread of a pandemic to Hong Kong and protect the health of our residents who return to Hong Kong, we may need to take quarantine measures such as requiring those returning to Hong Kong during a pandemic outbreak to undergo medical examination, medical surveillance, medical treatment and quarantine," he said.

While outbreaks of avian influenza in birds have been reported recently in many neighboring regions, along with sporadic cases of infections in people, Hong Kong has remained infection-free since 2004.

"The WHO has also maintained that there is as yet no evidence of effective human-to-human transmission of avian influenza. That said, we cannot rule out the possibility of strain mutation. We therefore should remain vigilant, continue to get ourselves prepared, keep a close watch on the epidemic development, and take preventive and control measures as appropriate," Chow stressed.

To prevent and control the global spread of disease, the World Health Assembly adopted the International Health Regulations 2005 in May. They stipulate that countries should avoid unnecessary interference in global traffic and trade and respect fundamental human rights when implementing disease-control measures.

The WHO, however, is empowered to issue temporary recommendations on restrictions of the movement of people and goods depending on the seriousness of an epidemic. These may include goods inspections or medical examinations, quarantine and even refusal of entry of those goods or people suspected to have been infected.

"These principles and provisions laid down by the WHO will be complied with when the time comes for us to decide what port health measures are to be taken," Chow said.

He added the enormous flow of passengers and goods between the Hong Kong and the Chinese mainland makes it necessary to step up public health surveillance and control at immigration control points if and when the risk of an avian influenza outbreak becomes higher across the border.

"When deciding on actions to be taken, we will consider, among others, the prevailing condition of epidemic outbreak, mode of epidemic transmission, efficiency of its transmission, scale of spreading and incubation period, the prevailing situations in Hong Kong and our neighboring regions, the latest scientific evidence as well as the WHO's recommendations, so as to determine the most appropriate disease prevention measures to be taken at control points with regard to the risk level," he said.

The health chief said "we will strike a proper balance between effective disease prevention and smooth flow of passengers and goods."

(Xinhua News Agency November 23, 2005)