Vietnam told people on Wednesday not to handle dead chickens following the deaths of five people from the deadly bird flu virus and Thailand said it had its first case in poultry for two months.

More human deaths are feared. The World Health Organisation said in Geneva on Tuesday it had been told by Vietnam that up to 10 more suspected human cases were under investigation and the H5N1 virus kills a high proportion of the people it infects.

Seven Vietnamese have been confirmed as having the virus in the latest wave of outbreaks which have spread it across much of the country and five of them have died, taking the human toll to 37 - 25 in Vietnam and 12 in Thailand.

The latest confirmed case was the first in the north. State media quoted officials as saying a 42-year-old man being treated in a Hanoi hospital had tested positive for the H5N1 virus.

All the others were from the south, including the latest victim, a 35-year-old woman from Tra Vinh province who died on Tuesday.

Like three of the others who died, she had been in contact with infected poultry. The fifth, a 9-year-old boy, died after swimming in water where dead poultry had been thrown.

The government not only told people to avoid handling infected chicken, it said they should not eat it unless they knew exactly where it came from.

In Thailand, the world’s fourth biggest chicken exporter before bird flu struck last year, a single chicken at an isolated house in the eastern province of Rayong had been confirmed to have been infected by the virus.

The remoteness of the Rayong house led officials to believe the chicken had been infected by wild birds, Livestock Department chief Yukol Limlaemthong said.

FIVE DEATHS

Migratory wild fowl, which can carry the virus without showing symptoms, are widely blamed for bringing it to Asia and experts say H5N1 is now endemic in the region.

What the WHO fears most is that the virus could mutate if - and there is no evidence it has - it got into an animal capable of hosting a human flu virus.

That would probably be a pig and if the H5N1 were to merge with a human flu virus, it could produce a strain which could sweep through a human population without immunity to it and kill millions, the WHO says.

Among suspected cases reported in Vietnam’s state media was a 35-year-old patient taken from the southern province of An Giang to Ho Chi Minh City on Tuesday with fever and coughing after processing sick chickens.

Tests were also under way to see if the H5N1 virus killed a 17-year-old boy on Jan. 15 in Bac Lieu province, doctors said.

Vietnam has slapped a temporary ban on the import of poultry and poultry products from neighbouring countries as part of measures to contain bird flu. It imports chickens and eggs mainly from China.

An animal husbandry official in China’s Guangxi region bordering Vietnam told Reuters the government had sealed off border trade with its neighbour. Anybody found smuggling poultry would be jailed.

China, the world’s second largest poultry producer, is on high alert over bird flu but strict preventive measures so far had prevented a recurrence of infections which struck hard last year, industry and government officials said.

“I think the Chinese poultry industry has learned its lesson,” said an independent Beijing-based animal nutritionist specialising in the poultry industry. “The poultry companies are taking really great preventive measures.”

Thailand banned all poultry imports following its first outbreak last January.