GENEVA, Switzerland, Feb. 21 (UPI) -- The World Health Organization reaffirmed Tuesday the H5N1 bird flu virus has not mutated to a strain that passes among people.
The international health agency issued the statement to counter recent media reports speculating that mutations in the H5N1 virus have increased the likelihood of another pandemic.
WHO acknowledged the virus has undergone a number of changes since the first human infection in 1997, but said the changes have not had a significant impact on the disease in people.
"Human infections remain a rare event," WHO stated. "The virus does not spread easily from birds to humans or readily from person to person."
However, the agency added, "Specific mutations and evolution in influenza viruses cannot be predicted, making it difficult, if not impossible, to know if or when a virus such as H5N1 might acquire the properties needed to spread easily and sustainably among humans."
The H5N1 strain has infected 170 people and killed 92 in seven countries, including Cambodia, China, Indonesia, Iraq, Thailand, Turkey and Viet Nam.
