(Agencies)
Updated: 2004-02-04 08:32

The United Nations health agency sought Tuesday to dampen fears of bird flu striking large numbers of people, even as the death toll in Asia climbed to 13.

A 7-year-old boy became the fourth person to die from the disease in Thailand. Vietnam has reported nine fatalities.

"I think it's very important at this stage that we remain calm about worst-case scenarios," said Mike Ryan, head of the global epidemic response network at the World Health Organization. "What we're dealing with at the moment is small clusters of cases associated with exposure to poultry."

"We have a strain of influenza with the potential to pick up human genes, and we're nowhere close to declaring a pandemic," Ryan told reporters.

Asia's bird flu crisis topped the agenda at a three-day emergency meeting beginning Tuesday at the headquarters of the UN Food and Agriculture Organization in Rome. Experts hope to work out strategies for tackling the outbreak and preventing future one.

Joseph Domenech, chief of the FAO animal health department, addressed the concern the virus could mutate.

"Today we are not at this stage, but until now the veterinary, the animal outbreaks, are multiplying. It's still an increasing curve, so if it continues that way, the risks are still more and more important," he said.

Ten Asian countries are battling bird flu, also known as avian influenza, and at least 45 million chickens have been slaughtered across the region to stop its spread. Cases in humans have been reported only in Vietnam and Thailand, with most traced to direct contact with sick birds.

Fears the disease had spread to Europe subsided after doctors said a German tourist who came down with flu-like symptoms after visiting Thailand was most likely free of the disease.

Investigators have been unable to trace the infections of two Vietnamese women to contact with chickens and have not ruled out human-to-human transmission. But even if the women did catch the disease from a family member, limited transmission of the virus between people is not the real danger.

What experts fear most is the virus mutating into a form that passes easily between people - a pandemic strain that is a hybrid of the bird virus and a normal human influenza variety.

"What we're saying is that we're not dealing with an imminent threat to public health, but we are dealing with a potential threat to public health," Ryan said.

The other countries battling the disease are China, Vietnam, Cambodia, Laos, Indonesia, Japan, Pakistan, South Korea and China's Taiwan Province. However, health officials say the strain of bird flu striking Taiwan and Pakistan is milder and is not considered a serious threat to humans.

Ryan, who steered WHO's response to last year's SARS epidemic in Asia and Canada, said authorities worldwide must keep bird flu under close surveillance.

"This latest avian influenza outbreak sends another shot across the bows, another warning to us that we must be ready in the event of the emergence of a pandemic strain," he said. "While we're watching, we've got to be preparing."

WHO has sent teams to the region and to the meeting in Rome. At least 25 international experts from 15 countries were attending that meeting, including high-level veterinary officials from affected nations and representatives of the U.S. Centers for Disease Control and Prevention.

Health officials say destroying infected birds, if safely carried out, is the best way to contain the disease, but the mass slaughter and import bans have ravaged Asia's poultry industry.

WHO officials have said people who eat poultry are not at risk from bird flu but that import restrictions on live birds are needed to halt the spread of the disease among farm flocks.

The European Union and Japan have both barred poultry products from Thailand, with the EU extending its ban Tuesday for another six months. The extension also applies to a ban on pet birds from Cambodia, Indonesia, Japan, Laos, Pakistan, China, South Korea, Thailand and Vietnam.

Asian tourism has begun to suffer, although WHO has not issued any travel warnings as it did during the SARS outbreak.

WHO also is spearheading the hunt for a bird flu vaccine. Ryan said prototypes developed by the agency will shortly be supplied to pharmaceutical companies so they can begin research on a useable vaccine, which experts expect to be ready within months.

"This is something that is very achievable, this is not some brave new world," Ryan said. "Giving a worst-case scenario without taking into account our possibility to intervene successfully (with a vaccine) I think at this point would be scaremongering."