HANOI, Vietnam - Bird flu is popping up after a yearlong hiatus in Vietnam and elsewhere in Asia, and experts are warning now is the time for the H5N1 virus to flourish. The big question: Just how far will it go this winter?
As temperatures drop during traditional flu season, bird flu typically spreads. A year ago, the virus swept across countries in Africa, the Middle East, Central Asia and into Europe. Even so, officials say it's hard to predict what such an unpredictable virus will do.
"We're braced for basically a repeat of what we saw last year," Peter Cordingley, spokesman for the World Health Organization's Western Pacific region, said this week. "We're expecting more problems through the colder months as we head into February and March."
Last winter, a wave of bird flu was reported in many countries where the H5N1 virus was detected for the first time, including India, Iraq, Azerbaijan, Niger and France. Turkey was particularly hard hit last January when 12 people were infected, four of whom died.
Since December, flare-ups have caused the death or slaughter of 30,000 birds in Vietnam after no poultry outbreaks or human cases had been reported for a year. South Korea, which had not battled the disease in three years, also has slaughtered more than 1 million birds since the virus erupted in November.
Egypt last month reported three human deaths from the H5N1 virus, while Indonesia -- the country hardest hit by the virus with 58 deaths -- continues to report human cases. On Wednesday, a 14-year-old Indonesian boy died from bird flu, just days after being hospitalized, a health official said.
New fears also have surfaced in Hong Kong after a wild bird found dead tested positive for the virus on Saturday, and mainland China on Wednesday reported that the virus had last month infected a farmer, who has since fully recovered.
Despite the developments, some experts expressed optimism that the situation is improving globally and that a repeat of last year's pattern is unlikely.
The number of outbreaks among poultry today "pales by comparison" to early 2004, when bird flu first emerged in Asia, said Juan Lubroth animal health expert at the U.N. Food and Agriculture Organization in Rome.
"Although we see it in different places, at least the number of outbreaks and the chickens dying ... is not what it used to be," he said.
Even as the number of poultry outbreaks declined, reports of human deaths rose in 2006, killing 79 people.
Officials say the increase may be the result, in part, of better surveillance and reporting due to increased public awareness about bird flu.
The disease has claimed at least 157 lives worldwide since it began ravaging Asian poultry farms in late 2003, according to the WHO. Experts worry the virus, which remains hard for people to catch, will evolve into a form that passes easily among humans, potentially sparking a pandemic. So far, most cases have been traced to contact with infected birds.
As Vietnam prepares for next month's Lunar new year holiday, known as Tet, health officials are worried human cases could follow during the busiest time for the movement of people and poultry.
Vietnam was hailed for successfully beating back the virus after starting a mass national poultry vaccination program and involving the country's top leadership in raising awareness. But even after the long lull, the virus' resurgence has reminded everyone that it's far from gone.
"It shows that even if you take all these measures, you can't eliminate the virus if it has been widely spread in the environment in half a year or a year," said Hans Troedsson, WHO representative in Vietnam. "This is a very long-term undertaking."
