Neuraminidase inhibitors sensitivity in Cambodian H5N1 and H1N1 pandemic influenza viruses

Background Since 2003, H5N1 avian influenza strains have become endemic in many countries in Southeast Asia, including Cambodia. In Cambodia alone there have been 26 outbreaks in poultry flocks and 10 human cases with 9 deaths. We have analyzed the genome of a large panel of H5N1 strains isolated from poultry and human between 2004-2010. Several strains have molecular alterations which are predicted to affect sensitivity to neuraminidase inhibitors (NAI), the primary drugs of choice in the treatment of H5N1 infections. In June 2009 the first H1N1 pandemic (H1N1pdm) viruses were detected in Cambodia and have since been the main influenza strains circulating during the epidemic season. The aim of this study was primarily the surveillance of oseltamivir and zanamivir drug resistance in Cambodian H5N1 and H1N1pdm isolates.