The victim, a 15-year-old girl, lived in the Iraqi region of Kurdistan not far from the border with Turkey where four children have died of bird flu. The WHO is testing samples from the girl's uncle who died on Jan. 27 and a 54-year-old woman who is under treatment for respiratory illness.
Two more people in the area also "had symptoms suggestive of H5N1 infection," said the WHO. Earlier this week, Iraqi health officials said they were treating 12 patients suspected of the bird flu. Rumors of human cases in other parts of the country have not been confirmed.
Health experts are concerned that the virus, which has killed 86 people of 161 confirmed cases across Asia, Turkey and Iraq, will mutate to spread easily from human to human and spark a worldwide pandemic. Animal health officials say it is still an animal disease and most human cases have occurred as a result of close contact with sick birds.
The WHO praised local doctors in Iraq for identifying the infection, saying that the detection "indicated a high level of awareness of the clinical features of this disease and good vigilance on the part of clinicians."
The announcement of a human case in Iraq came before detection among the area's bird populations, prompting WHO officials to stress the need for better surveillance of birds.
The H5N1 virus is highly pathogenic and outbreaks in other countries have shown how quickly it can establish itself in poultry populations if preventative measures are delayed.
Poultry culling is already under way in northern Iraq, and a team of experts from the WHO, the Food and Agriculture Agency and the World Organization for Animal Health has been dispatched at the request of Iraq's Ministry of Health to help prevent the disease's spread. The team will not arrive until early next week due to the security situation.
Similar WHO-led teams already are present in Armenia, Azerbaijan, Egypt, Georgia, Iran, Lebanon, Moldova, Syria and Ukraine.