A student gets his temperature checked for bird flu symptoms in Hong Kong. (Reuters)

Hanoi/Bangkok, Feb. 2 (Reuters): Two more people have died after contracting bird flu, bringing to 12 the number of deaths in an epidemic that is sweeping Asia and which scientists fear may now be transmitted from person-to-person.

The deaths — a 58 year-old-woman in Thailand and a teenage boy in Vietnam — come a day after the World Health Organisation said two sisters who died in Vietnam last month probably caught the virus from their brother — the first cases of human-to-human infection in the current epidemic.

The brother also died, but he was cremated before an autopsy could be performed and so it could not categorically be determined if he was the original source. His wife also contracted bird flu but has since recovered.

Stock markets fell in Hong Kong and Thailand as economists said the possibility of human transmission would have much more serious implications.

The Severe Acute Respiratory Syndrome outbreak last year cost Asia an estimated $60 billion and there are worries that bird flu could have a similar or even worse effect if it spreads further. “At the moment the disease is largely restricted to where the chickens are,” said Rob Subbaraman, regional economist at Lehman Brothers.

“But if we got strong evidence of transmission from human-to-human and there was a risk of it getting into crowded areas like shopping malls and public transport, it would cause an economic disruption.”

In China, home to the largest number of poultry in the world, bird flu was reported from a new area — Gansu province in the northwest, state radio said today.

Eleven provinces and regions, about one-third of the country, have been affected by the virus and authorities there have culled tens of thousands of birds, including about 20,000 in Gansu.

Taiwan will launch temperature checks at its schools and increase patrols against illegal poultry smuggling to stave off the flu that has gripped the island’s neighbours, officials said.

Hospital officials in Vietnam’s southern city of Ho Chi Minh said the teenage boy who died today had caught the virus after eating meat from a chicken with avian influenza.

“The boy was admitted to the Hospital for Tropical Diseases in Ho Chi Minh City on January 29 and tested positive for the H5N1 virus on January 31,” said a doctor. A hospital official added: “We know he ate chicken that died from the bird flu virus.”

The latest Thai victim was a woman who raised chickens in Suphanburi province 100 km west of Bangkok.

More details of her death have yet to be released, but Prime Minister Thaksin Shinawatra — under fire for reacting slowly to the outbreak — lambasted the WHO for suggesting the flu could mutate and spread to pigs and then even more easily to humans.

“Ethically speaking, researchers should only discuss low possibilities of such cross-strain spreads in labs, not in public,” Thaksin said.

WHO said another Thai died several days ago from bird flu, but health ministry officials said the toll remained at three.