Many countries are doing a better job fighting the H5N1 bird flu virus, yet many outbreaks are not reported, Food and Agriculture Organization (FAO) officials said on Tuesday.

Absolute transparency about disease outbreaks, involving farmers directly in surveillance and reporting as well as compensation were key to make the global fight against bird flu successful, they said.

"So far, many countries have managed to progressively control the virus and the global situation has improved tremendously," Juan Lubroth, a senior FAO infectious diseases official, told a news conference.

"Unfortunately, at the global scale, many outbreaks remain under reported or unreported. National or international bodies are often not in a position to immediately verify rumors or reports about unconfirmed outbreaks," Lubroth said.

The number of outbreaks in the first weeks of 2007 had been significantly lower than the epidemic waves of last year despite new flare-ups of the virus so far in eight countries, including Indonesia, China, Egypt, Japan and South Korea, FAO officials said.

"The virus continues to persist in several Asian countries, as well as in Egypt and Nigeria," said Hiroyuki Konuma, the FAO´s deputy regional representative for Asia and the Pacific.

"Other countries may have been affected but have yet to report."  

Bird flu remains essentially an animal disease, but it is known to have infected 269 people worldwide since late 2003. Of these, 163 have died, fanning fears of a global human pandemic.

Since 2003, outbreaks have been confirmed in about 50 countries and territories.

The FAO said there had been no reports of new outbreaks in secretive military-ruled Myanmar or Laos and Cambodia, all neighboring Thailand, which had its first outbreak in six months earlier in January.

The spread of the virus by migrating wild birds from Asia to Europe and Africa had not taken place during this autumn/winter season at the same level as it had in 2005, the officials said.

But the poultry trade and the transport of live birds could still spread the virus and strong vigilance was needed.

"Recent outbreaks are following a seasonal pattern and do not come as a great surprise," Lubroth said.

"But we should remain alert as the recent outbreaks show. It is crucial that countries themselves set up their surveillance, detection and rapid-response measures," he added.

"Only immediate reporting of any suspected bird flu outbreak makes possible rapid intervention by farmers and veterinarians."

The officials also expressed concerns about bird flu spreading in Vietnam ahead the Tet Lunar New Year festival in mid-February when poultry is part of traditional feasts.

Vietnam has had no human H5N1 cases since November 2005 but the virus that first hit Southeast Asia in late 2003 returned to the Mekong Delta last month and has spread to a number of provinces.

"Yes, we are concerned about the situation in the upcoming holiday," said Laurence Gleeson, regional manager of the FAO´s emergency center for transboundary animal diseases.

"The question really will be to what extent the disease-control measures in place can stop the virus from spreading out."