Doctors fear bird flu strain which has killed 36 in China has become resistance to antiviral drugs
Shanghai doctors treated 14 H7N9 sufferers with Tamiflu drug
The virus showed resistance to drug in three of the sufferers
There have been 131 confirmed cases of the virus this year
But no new cases of H7N9 have emerged since May 8
By STEVE NOLAN
29 May 2013
A strain of bird flu which has killed 36 people in China can mutate to become resistant to antiviral drugs, say Chinese researchers.
Shanghai doctors treating 14 sufferers of the H7N9 virus found that it had become resistant to Tamiflu in three of the patients.
Researchers at the Shanghai Public Health Clinical Centre said that while the drug reduced levels of the virus in 11 of the patients, genetic testing of bird flu in the three who did not respond to treatment showed it was able to effectively mutate to resist Tamiflu.