The Black Vault - Bird flu death: Human link feared

BANGKOK, Thailand (CNN) -- -- Thailand says a woman has died from bird flu and signaled the possibility she may have caught it from her daughter, raising concern the virus can be passed between people.

Earlier this year, the bird flu ravaged Asia's poultry industry and jumped to humans in Vietnam and Thailand, killing 24. About 100 million chickens across the region were slaughtered to halt its spread.

But the people who succumbed to bird flu in that outbreak are all believed to have caught the disease from infected chickens. This latest case is the first being investigated as a possible person-to-person transmission.

On Tuesday, 26-year-old Pranee Thongchan became the 10th person confirmed to have died from bird flu after dying on September 20.

She had been caring for her 11-year-old daughter who died on September 8 but because her youngster was cremated before tests could be done, officials cannot confirm she died from bird flu.

Health officials have long feared the bird flu virus may mutate, making it possible for the illness to pass from person to person, but experts have so far played down the latest developments.

"If this episode of human-to-human transmission were confirmed it does not pose a significant public health threat, said Dr. Kumara Rai of the World Health Organization.

"There is no reason to be panicked."

The woman who died may have caught the flu from her village where chickens died or from her sick daughter whom she was taking care of at the hospital for a long time, the Thai health ministry said.

"In this case, if the mother had contracted the disease from her daughter it would have been due to very close and prolonged face-to-face exposure," the ministry said.

If the latest H5N1 death is ruled to be of the human-to-human variety, the WHO said it would not be because of casual contact -- like catching a cold -- but because of the mother's close contact while caring for her sick daughter.

The woman is the second Thai confirmed to have died of the disease since it resurfaced in July.

The mother lived outside Bangkok while her daughter lived in the northern province of Kamphaenphet, where she had come in contact with chickens.

Thailand, the world's fourth-largest chicken exporter, slaughtered more than 40 million birds in its bid to eradicate the virus earlier this year. The virus killed eight people in that episode.

There have been three confirmed cases of bird flu in Thailand during the current outbreak, which surfaced in July.

In addition to the woman, an 18-year-old man has died from the disease. A 32-year-old woman has been hospitalized.

Hospitals and health officials across the country have been put on high alert to monitor any return of the disease.