Foreign donors on Friday injected fresh funds into the global fight against bird flu, pledging nearly $476 million for surveillance and response strategies to halt its advance, especially in Africa.

The $475.9 million pledged on the final day of a three-day summit in Mali, West Africa, which brought together experts on avian influenza from across the world, was less than the total some organizers had hoped for.

Friday´s donor meeting, the fourth global bird flu summit since late last year, had aimed to secure $500-$750 million per year to fight the disease over the next two to three years.

But experts played down the apparent shortfall, saying they were confident further funds would be forthcoming from donor countries and financial institutions.

"We know there is more in the pipeline from countries that couldn´t give commitments for various reasons. I am personally confident that we will make the $500 million," U.N. influenza coordinator David Nabarro told reporters.

"It´s a really excellent result," he added.

John Underwood of the World Bank said multilateral financial institutions would also make more money available.

Of the total announced on Friday, the United States pledged $100 million, Canada $92.5 million and Japan $67 million. The European Commission pledged $88.2 million, which, added to individual nations´ pledges, made an EU total of $130.6 million.

World Bank and United Nations officials say the latest funds sought from donors -- over and above $1.9 billion pledged at a summit in Beijing in January -- are a fraction of the $2 trillion any human influenza pandemic could cost worldwide.

"It´s an ounce of prevention worth a ton of cure. The returns on prevention are unbelievable," said Olga Jonas, of the World Bank´s Avian and Human Pandemic Influenzas department.

AFRICA´S NEEDS GREATEST

She added: "The needs are greatest for Africa, so it´s only natural the great majority of what´s pledged here will be for Africa, but the situation may change in three or six months."

Asia, where the outbreak started, remains hardest hit, but the deadly H5N1 virus has spread rapidly through Eastern Europe and parts of Africa since the Beijing donor conference. An estimated 250 million poultry birds have died or been culled, and 154 humans who caught flu from sick birds have died.

Scientists fear the H5N1 virus, which can pass from sick birds to humans, may mutate and become able to jump from person to person, threatening a human pandemic such as the Spanish flu which killed tens of millions of people in 1918.

"If not detected, reported promptly and contained effectively, a pandemic could potentially kill millions and cause catastrophic consequences," the final summit communique said.

Even before the conference started there were signs of some potential disappointment about funding.

"What we regret very much is the absence of the Arab donors ... If there is a pandemic, the oil price will fall," said a source close to the donor talks.

Although Arab governments and institutions were mostly absent in Beijing, the source noted bird flu had since spread to the Arab world and Africa, which is a big recipient of Arab aid.