UN health experts have warned that Asia's bird flu outbreak is at a critical stage where it could easily become a human pandemic.
Dr Shigeru Omi, WHO
Dr Shigeru Omi of the World Health Organization said at the opening of a three-day UN conference on bird flu that the virus has "tightened its grip" on the region and is capable of springing major surprises.
"We believe we are at the tipping point. Either we . . . reverse this trend or things will get out of hand," Dr Omi said. "We must have an all-out war against this virus."
The virus, which has killed 54 people in Asia, appears to spread to people only when they come in close contact with sick poultry. Medical experts fear that the H5N1 bird flu strain could mutate into a form that easily passes between people and trigger a dangerous global pandemic because people have developed no resistance to the strain.
"The virus has behaved in ways that suggests it remains as unstable, unpredictable and versatile as ever," Dr Omi said. "Judging by its performance today we need to be on constant alert for surprises," he said in a speech earlier.