Updated

Health and food experts from around the world opened an emergency meeting Tuesday on Asia's bird flu outbreak as the death toll rose to 13 and U.N. officials sought to dampen fears of the virus striking large numbers of people.

A 7-year-old boy became the fourth person to die from the disease in Thailand.

The World Health Organization (search) confirmed that an 18-year-old Vietnamese man who died on Monday was a victim of the virus. He had already been included in the country's death toll, which stands at nine.

An outbreak in China's poultry stocks, meanwhile, appeared to widen with newly confirmed or suspected cases reported in six provinces.

Asia's bird flu crisis topped the agenda at a three-day emergency meeting that began in Rome on Tuesday at the headquarters of the U.N. Food and Agriculture Organization (search).

The experts meeting in Rome hope to work out strategies to help affected countries tackle the emergency as well as prevent future outbreaks. 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, its still an increasing curve, so if it continues that way the risks are still more and more important," he said.

In Geneva, the WHO sought to calm fears that two Vietnamese women may have contracted the virus from a human.

Investigators Monday announced they could not trace the infections of the two women to contact with chickens and said human-to-human transmission could not be ruled out.

"We do not at this stage have a pandemic strain of influenza," said Mike Ryan, head of WHO's global epidemic response network. "We have a strain of influenza with the potential to pick up human genes and we're nowhere close to declaring a pandemic."

Neither a human nor a chicken source could be ruled out in the Vietnam case, but even if the women did catch the disease from a family member, limited human-to-human transmission of the virus is not the real danger.

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

"What we really need to be able to do in this particular case is rapidly detect any (genetic) changes in the makeup of the virus," Ryan said. "We're not dealing with an imminent threat to public health, but we are dealing with a potential threat."

Indonesia acknowledged finding the same deadly H5N1 strain (search) of bird flu that has jumped to humans elsewhere in Asia, but said no people in the country have been infected. Previously local officials said only milder versions of bird flu — ones not known to infect humans — had been confirmed.

Ten countries are battling bird flu and at least 45 million chickens have been slaughtered across the region to stop its spread. Nations that have seen their poultry industries ravaged by the epidemic continued to struggle with the economic fallout Tuesday.

Vietnam tour operators reported mass cancelations while Thai officials gave away cooked chicken and eggs to restore confidence in their billion dollar poultry industry.

Malaysia, which has not reported any bird flu cases, said it has stopped giving chicken meat to animals at the national zoo and is feeding them rat and rabbit instead.

Fears that avian influenza 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.

FAO officials said they believe the disease is spreading within Thailand and Vietnam, but that the situation is less clear for China, where investigators may just now be picking up previously undetected cases.

Suspected cases in Chao'an county in China's southern Guangdong province were confirmed Tuesday. New suspected cases were reported in Gansu province in the west, Anhui in the east, Shaanxi in the north and the central provinces of Hunan and Hubei.

Governments battling the disease include China, Thailand, Vietnam, Cambodia, Laos, Indonesia, Japan, Pakistan, South Korea and Taiwan. However, health officials say the strain of bird flu striking Taiwan and Pakistan is milder and is not considered a serious threat to humans.

FAO announced it would give $1.6 million in emergency aid to Laos and Cambodia as well as Vietnam and Pakistan to help fight outbreaks in those countries.