Vietnam has banned transport of poultry and set up road checkpoints in parts of the southern Mekong Delta in hopes of controlling a spreading outbreak of bird flu among flocks, DPA QUOTED AN official as saying Friday. The deadly H5N1 virus spread to a third southern province this week after re-emerging in Vietnam 10 days ago, and Minister of Agriculture Cao Duc Phat issued urgent instructions to provinces to try to contain the outbreak. "We have been instructed to cull birds in the infected areas, disinfect the farms, set up checkpoints to stop the transport of poultries from infected areas and continue to vaccinate birds," said Nguyen Hien Trung, head of the animal department of Hau Giang province. Authorities hope to contain the avian influenza virus, which previously killed 42 people and millions of chickens in Vietnam, before it has a chance to become endemic in poultry and infect more humans. Vietnam had declared itself free of bird flu earlier this year after an aggressive poultry vaccination programme for 126 million chickens and ducks. But the virus reappeared in two provinces last week and was confirmed Thursday in Hau Giang, 220 kilometres southwest of Ho Chi Minh City. Officials have been slaughtering chickens and ducks in the affected districts as well as in nearby Bac Lieu and Ca Mau provinces, where the virus reappeared in Vietnam after more than a year's absence. The three provinces have so far culled nearly 14,000 ducks and chickens in and around the infected areas after 4,500 birds have been found dead since early this month, according to Hoang Van Nam, head of the Epidemic Unit under the Department for Animal Health. Officials warned that the measures might not be enough to contain the virus and that Vietnam could see a return to high levels of disease in poultry. "The possibility for the outbreaks to spread further is very high as the weather will keep cool, which is perfect for H5N1 virus to proliferate," Nam said. "In addition, this season is the migration season of wild birds in the region. Local farmers still underestimate the danger of an epidemic, and as the traditional lunar new year is approaching, local people will transport more birds," he said. Although bird flu has devastated Vietnam's poultry industry, the real concern is that its return in domestic poultry could infect more humans, who can catch it through close contacts with infected birds. At least 160 people have died of the disease worldwide since 2003. While H5N1 is not easily contagious among people, scientists fear that if the virus is left unchecked it could mutate to allow human-to-human transmission, which threatens the lives of millions of people who would have no natural immunity to a new influenza strain.