<p>Poultry farmers need to adopt strict hygiene standards to curb Asia's deadly bird flu virus, a top Vietnamese official said on the eve of an international conference Wednesday on fighting the disease.</p><p>A dozen Vietnamese have died of bird flu since Dec. 30, raising concerns that the disease could be re-emerging after an outbreak last year spread to 10 Asian countries, forcing the slaughter of more than 100 million birds.</p><p>"It's difficult to change their habit but we need to educate them," Bui Quang Anh, head of the Department for Animal Health, said Tuesday. "Once they understand and follow all the instructions, we can prevent the virus from spreading."</p><p>Big commercial farms learned from the first outbreak and applied preventive measures, such as strict hygiene standards and regular disinfection, Anh said. The most recent outbreak was only reported in small farms, which failed to apply preventive measures, he said.</p><p>New regulations should include separating ducks from chickens, requiring ducks to be raised in cages and improving hygiene measures, Anh said. Ducks should not roam freely in rice fields as they do now in the southern Mekong Delta, he added.</p><p>The conference will be looking at a variety of issues, including mass vaccinations, flu research, farm hygiene, animal husbandry practices and improving coordination between animal health and human health agencies.</p><p>The virus, which in the last year has killed 46 people _ including 32 from Vietnam and 12 from Thailand, has yet to mutate into a form that can be transmitted between humans. But scientists say it may mutate to a human form that could become as deadly as the ones that killed millions during three influenza pandemics of the 20th century.</p><p>Thailand's Cabinet on Tuesday approved a program to vaccinate free-range chickens, ducks, fighting cocks and tropical birds, reversing a ban that the government maintained on inoculating birds.</p><p>Details of its implementation will be decided after further study, government spokesman Jakrapob Penkair said.</p><p>Under the guidelines approved Tuesday, vaccines still will not be used on chickens raised in closed areas, where most fowl for export are raised, Jakrapob said.</p><p>There are fears that overseas customers would reject Thai poultry if it were vaccinated. Jakrapob said the government would consult with the industry.</p><p>"Vaccination is a way to curtail the spread of bird flu but it has to be combined with other methods, such as close monitoring and limiting the area in which free-range poultry are allowed to roam," said Dr. Charal Trinwuthipong, director of the Bird Flu Control and Prevention Center.</p><p>He said the bird flu epidemic in Thailand is "under control," with 26 areas in eight of the country's 76 provinces being monitored for possible infections.</p><p>On Monday, Dr. Julie L. Gerberding, head of the U.S. Centers for Disease Control and Prevention, said scientists expect that the virus will genetically change into a flu that can be transmitted from person to person.</p><p>The genes of the avian flu change rapidly, she said, and experts believe it is highly likely that the virus will evolve into a pathogen deadly for humans.</p><p>The mortality rate among people who caught the flu from chickens or ducks is very high _ about 72 percent of identified patients, Gerberding said.</p><p>"We are expecting more human cases over the next few weeks because this is high season for avian influenza in that part of the world," said Gerberding. Although cases of human-to-human transmission have been rare, "our assessment is that this is a very high threat."</p><p>The CDC chief said her agency was getting ready for a possible pandemic next year.</p><p>The U.S. government has ordered 2 million doses of vaccine for the known strains of avian flu. Gerberding said this would give manufacturers a head start on making the shots that would be needed to combat a full-blown epidemic in the United States.</p>
