2006-02-07-Experts warn bird flu more diverseUnderstanding Avian Influenza
2006-02-07-Experts warn bird flu more diverse
No country is fully prepared for bird flu, which is much more genetically diverse than previously thought, according to a global team of researchers.
One of the bird flu experts, Dr. Malik Peiris, professor of microbiology at Hong Kong University, told CNN Wednesday the deadly disease deserved all the attention it was getting.
Bird flu has claimed at least 86 lives around the world since 2003 and is the major concern this year of Asian populations, according to a December 2005 CNN/TIME survey.
With the disease spreading beyond Asia to the fringes of Europe in recent months, a senior World Health Organization official in Tokyo last month warned that the threat of a pandemic was "growing every day." (Full story)
Peiris is one of a team of 29 scientists who have just published a report on bird flu, in which they claim that there are four types of the deadly H5N1 virus.
The report appears in the online medical journal, "U.S. Proceedings of the National Academy of Sciences."
The scientists say in their report that the H5N1 virus -- which the World Health Organization says is responsible for more than 160 infections and the deaths of 86 people around the world since 2003 -- is more genetically diverse and can survive in birds showing no signs of illness.
Peiris said the problem of diversity and the disease's circulation in apparently healthy birds was a surprise and meant treatment options had to be looked at much more widely.
He told CNN that regional virus types meant there was a need to look for "broad cross-protection" rather than a single vaccine.
Peiris said that while wild birds may contribute to the introduction and spread of bird flu, the perpetuation of the disease was through stocks of domestic poultry.
He said no country was fully prepared to combat the disease, which needed to be tracked back and tackled at its source.
The diversity claim by the scientists has major implications for pharmaceutical companies and governments seeking to develop defenses against the spread of bird flu.
The scientists warn in their report that no single vaccine is likely to provide protection because the virus has developed into four distinct gene families, known as Z, V, W and the Mekong delta type.
They also say H5N1 has been endemic in southern China for almost 10 years, and can exist in apparently healthy birds.
The report says the best way to avert the bird flu threat is to control the infection at its source -- domestic poultry.
"Control of the regional epizootic (outbreak) and its attendant pandemic threat requires that the source of the virus in southern China be contained," it says.
In the past few days, Hong Kong has put its customs officers on high alert and tightened surveillance to stop people smuggling in birds and poultry.
Last week, a chicken brought illegally into Hong Kong from China was found to have had the H5N1 virus.
Most human deaths have been in Vietnam, Thailand, Indonesia and China, but in recent months the disease has spread beyond Asia to the Middle East and the fringes of eastern Europe.
Iraq reported its first human death from bird flu late last month, while at least 21 human cases -- including four deaths -- have been reported in Turkey since the start of the year. Infected birds have been detected in parts of Croatia, Romania and Russia.
About 200 million birds have died or been culled around the world since the disease first appeared in China's Guangdong province -- which adjoins Hong Kong -- in 1996.
Researchers have been particularly worried that the virus may mutate into a form capable of spreading rapidly from human to human.
Both the European Union and the United States have pledged large amounts of money in recent weeks to combat bird flu. In the U.S., Congress has approved $3.3 billion this year, of the $7.1 billion sought by President George W. Bush.