Bird flu virus mutating into human-unfriendly form
Thu Oct 4, 2007 8:24pm EDT
By Maggie Fox, Health and Science Editor
NEW YORK (Reuters) - The H5N1 bird flu virus has mutated to infect people more easily, although it still has not transformed into a pandemic strain, researchers said on Thursday.
The changes are worrying, said Dr. Yoshihiro Kawaoka of the University of Wisconsin-Madison.
"We have identified a specific change that could make bird flu grow in the upper respiratory tract of humans," said Kawaoka, who led the study.
"The viruses that are circulating in Africa and Europe are the ones closest to becoming a human virus," Kawaoka said.
