PANDEMIC WARNING: Millions at risk of bird flu: WHO

Thailand is beefing up its pandemic preparedness in response to the latest WHO study showing that bird flu is becoming more capable of spreading between people.

The World Health Organisation report was based on a recent study of the H5N1 avian-lu virus in northern Vietnam and other genetic evidence indicating that the deadly strain’s potential to infect people and generate a pandemic could be growing.

“The changes in the epidemiological patterns are consistent with the possibility that recently emerging H5N1 viruses may be more infectious for humans,” said the report, which emerged as the centre of discussion at WHO meetings in Manila, Hanoi and Geneva over the past two weeks.

The Public Health Ministry plans to call in more than 800,000 village health volunteers from around the country in two weeks to instruct them on how to educate their communities about the threat of an influenza pandemic.

Late next month, the ministry will hold a meeting of “Mr Bird Flu” medical specialists from every province to update them and exchange information on the latest development in Vietnam.

Influenza pandemics will also be a hot topic of discussion at the annual meeting of the epidemiologists next week, said Dr Kamnuan Ungchusak, director of the epidemiology bureau.

Kamnuan said the study in Vietnam found an increase in family clusters this year, a decrease in the fatality rate from about 70 to 30 per cent, and detection of H5N1 in people who did not show symptoms normally associated with bird flu, such as pneumonia.

“This new information give us good news and bad news,” he said. “Fewer deaths give us hope that there is a higher chance of success in treating patients. However, disease control will be much more difficult because there will be people walking around with normal cold symptoms and we won’t know whether they have H5N1 until we test them.”

Dr Prasert Thongcharoen, from Siriraj Hospital, the country’s leading microbiologist, said the WHO finding came as no surprise because the H5N1 strain has consistently changed its character since it was first detected in Hong Kong in 1997.

The reduction in the fatality rate was the natural evolution path of viruses, he said. By becoming less lethal the avian virus has possibly adapted to human hosts and can easily jump from people to people.

“The lower fatality rate is, in fact, a bad sign because it makes people think the problem has become less serious and then the surveillance system will weaken,” he said.

The virulent strain has killed 52 people in the region, claiming 36 lives in Vietnam, 12 in Thailand and four in Cambodia since late 2003. A second human case of bird flu was identified less than a week ago - in Vietnam on Tuesday.

As the hardest-hit country, Vietnam last month invited a WHO team of experts to assess its current situation.

“While the implications of these epidemiological and virological findings are not fully clear, they demonstrate that the viruses are continuing to evolve and pose a continuing and potentially growing pandemic threat,” the WHO report said.
“It is possible that avian-flu viruses are becoming more capable of human-to-human transmission.”

Dr Somchai Peerapakorn, WHO’s representative in Thailand, said the study confirmed that the influenza pandemic threat is mounting. As long as the virus is still in the environment, people are not safe.

“As long as the kettle is on the fire, the water temperature will continue to rise until it reaches the boiling point,” he said. “The pandemic threat will not go away because we don’t have a way to put out the fire yet.”

The WHO’s top influenza official, Klaus Stohr, told a WHO meeting in Geneva this week that conservative estimates indicate that up to 7.4 million people might die.

“The objective of pandemic preparedness can only be damage control. There will be death and destruction. National pandemic response plans are the key,” he said.

In January, Thailand put in place its national influenza pandemic preparedness plan, but a major premise - that the fundamentals of preparedness be worked out by the various ministries and the provinces themselves - has so far been slow in coming to fruition.

“But thing are changing now,” Kamnuan said. “We’re planning a tabletop exercise of the preparedness plan in every province as soon as possible.”

The WHO report raised other interpretations for the trends observed in Vietnam, including transmission through contaminated water or food, or infection from poultry that carried the virus but did not show symptoms, or greater persistence of the virus in the environment.

Nantiya Tangwisutijit
The Nation