Bird flu is a potentially lethal problem that will persist for years as the H5N1 virus strain continues to spread, pandemic experts were told Tuesday at an international conference in India.
"The virus is still being transmitted between chickens and it is going into wild birds, which are carrying it long distances as they migrate," said United Nations bird flu expert David Nabarro.
"Bird flu is a problem that will be with us still for some years to come," Nabarro said at the opening of an inter-governmental International Partnership on Avian and Pandemic Influenza conference, hosted by the Indian government.
Delegates from more than 100 countries were taking part in the meeting.
Another speaker, World Bank Director Peter C. Harrod, warned that bird flu is a long-term problem that must remain a priority for government officials and international donors.
He said the international community has pledged more than $2.3 billion to help developing countries fight bird flu and prepare for any possible pandemic.
The H5N1 virus had afflicted more than 60 countries, forcing the slaughter of hundreds of millions of birds since it began ravaging Asian poultry stocks in late 2003.
It is now entrenched in several countries, including Indonesia, Egypt and Nigeria, and has killed at least 206 people worldwide.
The virus remains hard for people to catch, but experts fear it will mutate into a form that spreads easily among humans, potentially sparking a pandemic. So far, most human cases have been linked to contact with infected birds.
Scientists say it is impossible to predict what the H5N1 virus will do, but as temperatures drop in the winter months there is a risk of bird flu outbreaks rising.
Officials in some Asian countries, such as Vietnam, have called for increased awareness and vigilance against the disease during the high-risk season.
The two-day New Delhi conference aims to draw up a sustainable plan to fight the threat of bird flu.