The rapidly spreading bird flu virus has been detected for the first time in Africa, infecting chickens at a large commercial farm in Nigeria, the World Organization for Animal Health reported Wednesday.
Tests conducted at a laboratory in Italy have confirmed the virus as the H5N1 strain, which has sickened 165 people in Asia and the Middle East, killing 88.
Although there have been no reports of the virus infecting humans in Africa, health officials expressed concern over the outbreak spreading to another continent.
"It's a very worrisome situation because it's in a big country with a lot of poultry farms," said Joseph Domenech, chief veterinary officer for the United Nations' Food and Agriculture Organization. "It has good conditions to have several outbreaks."
Over the last two years, the virus has spread from the Far East and Southeast Asia into Europe and the Middle East.
The virus, which is deadly to many types of birds, rarely infects humans. But each new human case increases the chance of it mutating slightly, allowing it to infect humans more easily.
The spread into Nigeria raises particular concern for public health officials because many villagers there live in close quarters with chickens, said Maria Cheng, a spokeswoman for the World Health Organization.
Public health systems in Africa are already straining to battle polio, AIDS, malaria and other serious diseases, Cheng said.
Nigerian authorities first became aware of the outbreak Jan. 10 in Jaji, a village in the north, according to the World Organization for Animal Health.
Since then, 42,000 birds have been infected and 40,000 have died, according to the agency.
Domenech said his organization and others have not yet determined the source of the outbreak but plan to send investigators to Nigeria today.
One possibility was the migration of wild waterfowl to Africa. Those wild birds may have mingled with domesticated birds.
"If it's not wild birds, it will be difficult to understand," Domenech said. "There is no real trade between the Middle East and Asia and Nigeria."
The Nigerian birds do not represent any direct threat to America, bird flu experts in the United States said Wednesday. Migrating birds in Nigeria do not cross the path of other birds that journey from Asia and Siberia to Alaska, said John Fitzpatrick, director of the Cornell University Laboratory of Ornithology in New York.
