However, Dr. David Nabarro also acknowledged that the virus has not yet shown signs of mutation. The virus has caused 88 deaths since 2003, however, most of those infected had contact with infected poultry.
Health officials have warned of the potential for the virus to mutate into a form that is easily spread among humans. "Unfortunately, we cannot tell when the mutation might happen, or where it might happen, or how unpleasant the mutant virus will turn out to be," Nabarro said in an interview with the Associated Press.
"Nevertheless, we must remain on high alert for the possibility of sustained human-to-human virus transmission and of a pandemic starting at any time."
He said that the fact that the bird flu has spread to African nations should serve as "a strong wake-up call" to countries around the world and that veterinarians worldwide should be on alert looking for the disease.
"We have got bird flu now in southeast Asia, central Asia, eastern Europe, and west Africa," he said. "Compared with eight months ago, this is a major extension of the avian influenza epidemic."
He also said that countries worldwide should be implementing policies to protect poultry populations from getting infected as well as procedures for dealing with human contact and infection should the flu continue to spread.
