A report last month from researchers in Vietnam, Japan, and the United States suggests that drug resistance may be emerging in H5N1 avian influenza virus, heightening concerns about preparedness for a potential pandemic (Le et al. Nature. 2005;437:1108).
The virus was isolated from a Vietnamese teenager who had been treated with prophylactic doses of oseltamivir, a neuraminidase inhibitor currently used for protection against and treatment for influenza, including H5N1 avian influenza. The girl was subsequently treated with higher doses of the drug and recovered.
Stephenson J. Drug-Resistant Avian Flu. JAMA. 2005;294(19):2423. doi:10.1001/jama.294.19.2423-a