Tamiflu may be resistant in some bird flu

HANOI, Vietnam, Oct. 14 (UPI) -- The H5N1 strain of bird flu that infected a Vietnamese girl in February was resistant to the antiviral drug Tamiflu, say researchers.

Yoshihiro Kawaoka of the University of Tokyo and colleagues at the University of Wisconsin at Madison say while the girl recovered, stockpiling the drug Tamiflu, also known as oseltamivir, may not be that helpful in fighting a pandemic.

The girl could have been infected by her brother rather than directly by birds, and the researchers identified a mutation in the virus strain that rendered it resistant to oseltamivir. However, the resistant virus was found to be sensitive to zanamivir, also known as Relenza.

Cases of suspected transmission of the virus from human to human need to be investigated and verified before the implications can be assessed, says Kawaoka.

"It could be useful to stockpile zanamivir as well as oseltamivir in the event of an H5N1 influenza pandemic," the authors concluded in an article published in the Oct. 20 issue of Nature.