Countries battling bird flu should focus more on the risk to people’s health than on the economic impact and Thailand might be rushing to declare its outbreak over, the World Health Organization said on Tuesday.
“Our main concern at WHO is that there is too much emphasis on the economic impact and too little emphasis on the risk to human health,” said Bjorn Melgaard, the WHO representative in Thailand.
“This could lead to an increased risk in either getting a pandemic or a larger human outbreak than what we are currently experiencing,” he told Reuters in an interview.
The virulent H5N1 bird flu virus has broken out in eight Asian countries, devastated poultry flocks and killed at least 14 people in Vietnam and five in Thailand.
More human cases likely
The human victims are all believed to have caught the disease from contact with sick chickens but there are fears the bird flu virus could combine with a human flu virus and mutate into a new deadly disease that could be passed between people.
The U.N. health agency says it expects people to be infected by the virus beyond Vietnam and Thailand, the world’s fourth biggest chicken exporter.
“It can be anticipated that human cases will also be detected in other countries where outbreaks of poultry are spreading,” the WHO said in a statement issued from its Geneva offices on Monday.
WHO also said it had jumped the gun in declaring tests on victims had shown no genetic evidence that bird flu could be passed from person to person.
It said latest information showed that it was too early to make that conclusion.
Last Friday’s announcement by the United Nations agency had been greeted with huge relief because of fears that the deadly virus, which has prompted the culling of millions of chickens and other fowl across Asia, could spread quickly amongst humans.
But the WHO said that there had been a mix-up in the testing of two Vietnamese sisters who died after catching it, and that results initially given for one of them had turned out to be from another victim instead.
“The sequencing announced Friday by WHO showed that the two viruses were both entirely of avian origin with no human genes, indicating the viruses had not become adapted to be easily transmitted from one human to another,” the Geneva-based body said in a statement.
“Today, WHO has learned that the virus from only one sister has been sequenced,” it said, adding that the results from the other sister were expected later this week.
Until then, no firm conclusions could be drawn, particularly because it was the second, so far untested sister, who was of particular interest, WHO officials said.
“She was the one who apparently had had no direct contact with any diseased bird,” said WHO spokesman Dick Thompson. “So we cannot rule out human-to-human transmission,” he added.
The H5N1 virus has hit Vietnam the hardest, killing at least 14 people. It has also infected flocks of chickens and ducks in South Korea, Japan, Thailand, Cambodia, China, Laos and Indonesia.
Health experts have warned that it has the potential to cause a serious epidemic among people if it acquires the ability to pass easily from person to person.
New outbreaks in China
Meanwhile China confirmed four new outbreaks of bird flu in provinces previously suspected of harbouring the H5N1 virus, but said there were no reports of human infections in the country, state radio reported on Tuesday.
Fourteen of China’s 31 provinces have confirmed or suspected outbreaks of avian influenza. The widening outbreak has fuelled speculation that human cases may have gone undetected.
“Clearly we are in an early stage in China,” said Melgaard.
“We would expect that there would be human cases in countries with large outbreaks, but so far they have not been detected and perhaps it is because the surveillance system has not yet been cranked up to detect those cases,” he added.
Fears virus may linger
In Thailand, Health Ministry officials feared the country was moving too fast towards declaring its bird flu epidemic under control and lowering its guard against fresh outbreaks.
The government says the last of 163 “red zones” should be cleared this week and there had been no reports of poultry dying in former red zone areas for three straight days.
“If we don’t find new cases by the end of this month, the government will declare all zones poultry-disease free,” chief government spokesman Jakrapob Penkair told reporters.
But health officials say the crisis is far from over.
“We will continue to strictly monitor the disease because we are not confident all diseased chickens in formerly infected zones would have been culled,” said Charal Trinwuthipong, chief of the Health Ministry’s Department of Disease Control.
“The outbreak is not over yet; it has just receded. We will continue to impose rigid surveillance measures to prevent the transmission of the disease to people nationwide,” he said.
Thailand, one of the worst-hit of the eight Asian countries, ordered the slaughter of all poultry within a red zone five km (three miles) around a confirmed outbreak.
Accused by newspapers and the political opposition of covering up the bird flu crisis initially, the government says it acted swiftly once the presence of the virus, which led to import bans by Japan and Europe, was confirmed.
Melgaard said the risk to people has not waned.
“The concern that the outbreak may still linger in certain areas and the risk to human health is still there,” he said.
Experts say the chance the H5N1 virus could mutate and sweep through a human population with no immunity to it is remote, but each outbreak shortens the odds.
Melgaard said it was not clear that all those involved in culling chickens wore proper protective gear. He also urged the government to reach out to backyard farmers who may have small outbreaks which go undetected.