Vietnam culled 450 ducks in its largest city on Thursday, its latest attempt to stop the spread of the bird flu virus that has killed 34 people across Asia and ravaged the region’s poultry industry.

Officials said on Friday doctors in Ho Chi Minh City had also received another patient suspected of carrying the virus, which has killed two Vietnamese boys since Dec. 30, taking the country’s death toll to 22.

Bird flu also killed 12 people in Thailand last year, but no new cases have been reported there since November. Malaysia, which has had no human cases, declared itself free of the virus on Thursday.

The World Health Organisation warned Vietnam may face new bird flu cases this month as poultry is moved around the country ahead of the Lunar New Year celebrations. The virus also becomes more active when temperatures cool, the WHO said.

An 18-year-old suspected bird flu patient was transferred on Thursday to Ho Chi Minh City’s Hospital for Tropical Diseases from the Mekong delta province of Tien Giang, the state-run Tuoi Tre newspaper said.

Tests this week showed bird flu killed a 6-year-old boy on Dec. 30. A 9-year-old boy died on Tuesday, the first bird flu death of 2005, and a 16-year-old girl remains in a critical condition, doctors at the hospital said.

Vietnam’s health ministry has advised consumers not to eat poultry that has died of unknown causes, is of unclear origin or has not been quarantined.

An official at Ho Chi Minh City’s animal health department said the infected ducks had been found in an outlying district of the city, which is home to 10 million people.

Since December, about 34,000 poultry have been culled or have died from bird flu in Vietnam, mostly in the country’s south.

Bu Jan. 6, the H5N1 virus had spread to 13 provinces and Ho Chi Minh City. Nine of the provinces are in the Mekong delta, where the epidemic broke out in late 2003 before spreading across the country to wipe out 17 percent of all poultry stock.

“We have yet to ban supplies from affected provinces (in the Mekong delta), but all incoming poultry has to go through quarantine,” the Ho Chi Minh City animal health official said.

He said inspection of all poultry shipments to Ho Chi Minh City has been tightened since Jan. 1 and that the transport of live poultry on passenger buses has been banned.

Vietnam’s government is also concerned that chickens and ducks are being smuggled into Vietnam from China, prompting it to announce a new campaign to tighten border controls.