Africa's first outbreak of the deadly bird flu virus was reported Wednesday in a large commercial farm in Nigeria that raised chickens, geese and ostriches, and 46,000 birds were slaughtered.
International health officials called for help to prevent the spread of the disease on the world's poorest continent, where governments are ill-equipped to combat it.
Nigeria said the outbreak was on a farm in Jaji, a village in the northern state of Kaduna. Agriculture Minister Adamu Bello told reporters the deadly H5N1 strain of the virus was detected in samples taken Jan. 16 from birds on the farm.
Nigeria, Africa's most populous nation with 130 million people, said it would work aggressively to halt the flow of any sick birds to unaffected zones. But farmers accused the government of being slow to respond.
Alex Thiermann, an expert with the Paris-based World Organization for Animal Health, said it was not known how the virus entered Nigeria, but migratory waterfowl likely played a role because the country is on a "major flyway."
No cases of H5N1 bird flu have been reported elsewhere in Africa, and the outbreak appears to be restricted to birds, he said.
"The significance is that it's a completely new continent that we need to be looking at," Thiermann said.
Sub-Saharan Africa, with about 600 million of the world's poorest people, is particularly ill-suited to deal with a major health crisis. With weak and impoverished government institutions in regions where many people keep chickens for food, experts say any mass killings — often a first step in controlling bird flu — will be difficult to pull off.
China, meanwhile, announced another human case of the disease — a 26-year-old woman — bringing to at least 11 the number of people in China who have been infected. Two have died.
The World Health Organization said Nigeria has about 140 million poultry and the country's overtaxed veterinary services need international help. It called on other African countries to act quickly against any suspected outbreaks.
"If the situation in Nigeria gets out of control, it will have a devastating impact on the poultry population in the region," said Samuel Jutzi, head of the U.N. Food and Agriculture Organization's Animal Production and Health Division. "It will seriously damage the livelihoods of millions of people and it will increase the exposure of humans to the virus."
Bird flu began ravaging poultry across Asia in 2003, forcing the slaughter of more than 100 million birds and jumping to humans. WHO has confirmed 88 deaths from bird flu out of a total of 165 cases of human infection. Almost all the cases have been in Asia, but the disease recently has been detected in Europe and the Middle East.
Though all the people who contracted the disease so far are believed to have been infected through contact with sick birds, experts are concerned the virus could mutate into a form easily spread from human to human, potentially triggering a global pandemic.
All 46,000 chicken, geese and ostriches on the Nigerian farm were slaughtered and their bodies disposed of, Thiermann said. Nigerian authorities have banned the movement of birds and people off the farm.
"We shall quarantine and stamp out all livestock in any farm suspected of having avian influenza and pay full compensation to the owners," Bello said.
Thiermann said that was a good start, and a team of experts to assess and provide technical advice will leave for Nigeria in a few days, although more help was needed.
"We feel that they are doing everything they can and they certainly need help," he said of Nigeria.
Officials also are investigating whether birds were transferred to other farms in the past 21 days, and they, too, are being quarantined, he said.
Nigerian officials said Wednesday that initial tests on chickens that mysteriously died in Kano, a state neighboring Kaduna, showed no signs of bird flu. Salihu Jibrin, head of the state's livestock department said at least 60,000 birds have died in Kano state in recent weeks, and tests were ongoing.
Awalu Haruna, secretary of the Poultry Farmers' Association of Kano, accused the government of being slow to respond to the epidemic of poultry deaths in the state.
"The government should have quarantined the affected farms to prevent further spread," he said. "But as I speak this has not been done. There is still movement of humans and birds in and out of these farms."
A laboratory in Padua, Italy, identified the H5N1 strain in the Nigerian birds, the World Organization for Animal Health said. It said further tests were being carried out to determine how closely the Nigerian strain matched the H5N1 strain detected elsewhere in the world.
The Italian Health Ministry said the bird flu strain is very similar to those found in Siberia and Mongolia.