World Health Organization officials urged governments on Wednesday to act swiftly to control the spread of bird flu, warning that the world is in grave danger of a deadly pandemic triggered by the virus.
The illness has killed 45 people in Asia over the past year, in cases largely traced to contact with sick birds, and experts have warned the H5N1 virus could become far deadlier if it mutates into a form that can be easily transmitted among humans. A global pandemic could kill millions, they say.
“We at WHO believe that the world is now in the gravest possible danger of a pandemic,” Dr. Shigeru Omi, the WHO’s Western Pacific regional director, said Wednesday.
He said the world is “now overdue” for an influenza pandemic, since mass epidemics have occurred every 20 to 30 years. It has been nearly 40 years since the last one.
Better coordination critical
Speaking at the opening of a three-day bird flu conference in Vietnam's Ho Chi Minh City, Omi said it is critical that the international community better coordinate its fight against the virus.
As bird flu experts met to devise plans to combat the H5N1 virus, scientists said they lacked knowledge about whether the strain that has led to the slaughter of tens of millions of birds has the pandemic potential of the 1918 Spanish flu that killed between 20 million and 40 million people.
They cautioned that more evidence is needed about how infectious the virus is in humans.
To become a pandemic strain, H5N1 would have to adapt sufficiently on its own, or mix its genetic material with a human virus to become highly infectious in humans who have no protection against it.
“We don’t know whether the virus that is currently circulating among poultry in southeast Asia, the H5N1, will eventually be able to reassert its genetic material with a human influenza virus. That is the key question,” Professor Albert Osterhaus, a leading European virologist at Erasmus University Hospital in Rotterdam, told Reuters in an interview.
So far the H5N1 strain has shown no evidence that it has become highly infectious in humans. Scientists also do not know how many people may have been exposed to it.
But Laurence Tiley, a molecular virologist at Cambridge University in England, said the H5N1 strain is lethal.
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“It is the most likely candidate for adapting and becoming a pandemic strain because we are not going to be able to get rid of it easily,” he said.
Preparedness plans urged
The U.S. Centers for Disease Control and Prevention is taking the threat of a possible pandemic "very seriously" and is working closely with the global health community to quickly detect any emergence of the new strain, CDC spokesperson Tom Skinner told MSNBC.com on Wednesday.
The mortality rate among identified patients who contract the disease from chickens and ducks is about 72 percent, said Dr. Julie Gerberding, head of the of the CDC.
However, on Tuesday she downplayed an earlier report about a possible avian flu pandemic.
"We are ... not on the brink of an avian flu epidemic," she said at a National Press Club luncheon.
But officials with the WHO appeared far more concerned about the possibility of a bird flu epidemic. In comparing the deadly virus to severe acute respiratory syndrome, or SARS, which killed nearly 800 people in 2003, Omi said, “If the virus becomes highly contagious among humans, the health impact in terms of deaths and sickness will be enormous, and certainly much greater than SARS."
The challenge for many countries is the lack of diagnostic tools and surveillance systems needed for early warnings, said Omi.
“This is why we are urging all governments to work now on a pandemic preparedness plan — so that even in an emergency such as this they will be able to provide basic public services such as transport, sanitation and power,” he said.
The disease, which devastated the region’s poultry industry last year as it swept through nearly a dozen countries, has killed 32 Vietnamese, 12 Thais and one Cambodian over the past year.
'Very resilient' virus
Officials acknowledge that one of the biggest challenges in controlling avian flu is in altering traditional farming practices in Asia where animals live in close, often unsanitary quarters with people.
Dr. Samuel Jutzi, of the United Nation’s Food and Agriculture Organization, said the avian flu virus will persist in Asia for years and coordinated efforts need to focus on controlling it at its source — in animals.
“This means addressing the transmission of the virus where the disease occurs, in poultry, specifically free-range chickens and wetland dwelling ducks, and thus curbing the disease occurrence in the region before it spreads to other parts of the world,” he said.
The regional conference held in southern Ho Chi Minh City near the Mekong Delta where the latest outbreaks emerged this year has brought together scientists and representatives from more than two dozen countries.
Bird flu’s reemergence in Vietnam has shown the virus is now endemic in parts of the region.
The virus has proven to be “very versatile and very resilient,” and has even been found in animals such as tigers and cats that weren’t believed to be susceptible to influenza, he added.
The Associated Press and Reuters contributed to this report