IT was an act of faith for Hoang Van Manh, a 36-year-old Vietnamese poultry farmer, to keep feeding his 2,000 valuable chickens in early 2004, when bird flu swept through Vietnam, claiming human lives, and shutting down the once brisk poultry trade.
Owner of three large egg incubators, Mr Manh had prospered by selling newly hatched chicks to other farmers. But as demand for birds dried up, the backyard hatchery operator was forced to kill 20,000 unwanted chicks, and destroy 30,000 fertilised eggs.
But Mr Manh's village, on Hanoi's outskirts, was further than 5km from any confirmed bird flu cases, so he was not required to cull his adult birds. Instead, he spent 1m dong ($60, £35) a day feeding them during anxious months without sales.
"The government was calling for farmers to change to other jobs, instead of poultry raising, but I trusted that the authorities would be able to control this bird flu problem, and that we would be able to go on," he recalls.
Mr Manh's faith was not misplaced. Vietnam - where bird flu once raged seemingly out of control in poultry, and where the virus killed 42 of the 92 people infected - is an example of how determined, comprehensive efforts can check the potentially lethal virus.
After culling 51m birds, or more than 17 per cent of the domestic poultry population, and conducting a comprehensive vaccination campaign, Vietnam has not registered any human avian influenza cases since mid-November, nor any outbreaks in birds since mid-December.
Its success is in stark contrast to countries like Indonesia, where bird flu has killed at least 42 people since July 2005, but is doing little to tackle the virus.
Vietnam's combination of aggressive culling, vaccination and intensive surveillance - using a Communist party apparatus that penetrates even remote villages - is seen as a potential model for authorities from other developing countries.
Still, agricultural experts caution that the lethal H5N1 virus is almost certainly present in migratory birds, waterfowl and ducks, while domestic birds smuggled over the border from China could introduce the virus. Small disease outbreaks in domestic poultry could be passing unnoticed.
"It's like a ceasefire - some sort of temporary respite," said Jeffrey Gilbert, a Hanoi-based expert on avian influenza from the United Nations' Food and Agriculture Organisation (FAO). "But the virus is not gone, and we wouldn't be in the least bit surprised if there was a new outbreak."
Bird flu spread widely in Vietnam before authorities recognised the threat in early 2004 and moved into battle mode. While Hanoi was not able to enforce fully its bans on poultry movements, duck-raising and live bird markets or its aggressive culling programme, its authoritarian Communist structure proved useful for disease surveillance, raising public awareness and ensuring reasonable compliance with various restrictions.
When outbreaks persisted through mid-2005, Hanoi raised the compensation for dead and culled birds to 50 per cent of market value, up from 10 per cent, encouraging more co-operation from farmers. Then in October, Vietnam launched an expensive, logistically complicated campaign to vaccinate domestic poultry. Taken together, the measures appear to have checked the virus.
Vietnam's battle against bird flu is far from over. Bui Quang Anh, director of the government's Department of Animal Health, said Hanoi was worried about bird flu in China, and the uncontrolled cross-border poultry trade. Public complacency about bird flu posed another risk.
"If people get tired and don't take precautionary measures, the situation will be very dangerous," he said. "If we don't pay attention, bird flu may re-erupt."
Rapid response will be crucial after 2008, when Vietnam is likely to end its vaccination programme. "We want to be sure that we don't have a repeat performance," Mr Gilbert said.
Hanoi has asked the international community for $266m (€210m, £143m) in aid to boost veterinary services and disease control, restructure its poultry industry and improve health services.
But to Mr Manh, now back in business, the future looks bright. After a slow start, sales are picking up, as farmers rebuild their own poultry flocks. His adult birds have been vaccinated, and his monthly profits are about 10m dong, on revenues of 40m dong. He is planning to expand his flock to 3,000 birds. "Things are getting better," he said. "Not many farmers are still worried about bird flu."
FT Syndication Service