David Nabarro said the situation is "really improving" as countries have generally invested in improving their veterinary and biosecurity services.

Although the situation is not completely under control, Nabarro said there is "a great deal of vigilance and action under way".

But the UN executive continues to post high alert for the possible mutation of the virus into one communicable between humans.

He highlighted intensive action by South Korea and Britain to bring outbreaks under control, as well as financial sector exercises in Australia and the United States to prepare for the impact of potential avian influenza crises.

The good preparedness in the travel and tourism sectors, as well as progress on updating international health regulations which countries adopt when confronted with major health emergencies is also a factor in keeping the disease from further outbreaks.

Nabarro, a British, was tasked by the world body in 2005 to lead efforts to contain the bird flu crisis.