The fight against bird flu has improved around the world, but the situation remains critical in Egypt and Indonesia where the risk of the H5N1 virus mutating into a major human threat remains high, the UN health agency said Wednesday.
"In the 15 or so countries in Asia, Eastern Europe and the Middle East where the H5N1 virus was introduced during the past six months, it was rapidly detected and eliminated or controlled," said Joseph Domenech, head of veterinary services at the World Health Organization (WHO) in Rome.
"Most affected countries have been very open about new outbreaks," he said. "This shows that countries are taking the H5N1 threat seriously. They are better prepared today and have improved their response systems."
But, speaking to reporters at a WHO technical meeting on avian influenza, he warned that Indonesia was "where the risk is the higher of getting the virus at the origin of human pandemic, as it was in China, Vietnam and Thailand three years ago".
"Same conditions in Egypt," Domenech added. "There is a high density and a lot of contacts."
"The H5N1 virus is not stable and keeps constantly changing," Domenech warned.
"On one occasion in China last year a new virus strain appeared with different immunologic characteristics which made it necessary to modify the vaccines used in the region concerned.
"This emergence of a new strain may have happened again more recently in Indonesia."