MADISON - Since it first appeared in Hong Kong in 1997, the H5N1 avian flu virus has been slowly evolving into a pathogen better equipped to infect humans. The final form of the virus, biomedical researchers fear, will be a highly pathogenic strain of influenza that spreads easily among humans.Now, in a new study a team of researchers from the University of Wisconsin-Madison report the identification of a key step the virus must take to facilitate the easy transmission of the virus from person to person.
