A Vietnamese patient has demonstrated partial resistance to Tamiflu, the antiviral drug experts plan to use against a human bird flu outbreak. At present, H5N1 flu strain poses a limited threat to humans, as it cannot spread easily between people.
Researchers warn that using Tamiflu (oseltamivir) for too short a time or at too low a dose could contribute to the emergence of resistant virus. The drug does not cure the disease, but keeps down the level of infection so the body’s natural immune response can fight the virus.
A 14-year-old Vietnamese girl was given the drug in February 2005 as a preventative measure. Although she had not had any known direct contact with infected poultry, she had been caring for her 21-year-old brother who was thought to have contracted avian influenza. The virus detected in the girl resembled that found in her brother. The girl recovered without any problems, but her case raises the possibility that she could have been infected by her brother, rather than directly by birds.
Oseltamivir on its own may not be sufficient to fight an H5N1 pandemic, and other drugs from the same family such as Relenza (zanamivir) may be needed too, say the researchers.
