Serological Surveillance of Avian Influenza Virus in Nepal

A serological survey for Avian Influenza Virus (AIV) subtype H5, H7 and H9 antibodies in domestic ducks was carried out in 2009 at Central Veterinary Laboratory (CVL), Kathmandu, Nepal. A total of 1000 serum samples were tested from various localities of 11 districts of Nepal, categorized as to be at high risk for the introduction of Highly Pathogenic Avian Influenza Virus (HPAIV) of H5N1 subtype. Sero-positive result against AIV H5 was found in three districts of eastern region with the highest prevalence (6.28 %) in Jhapa (p< 0.001). Likewise, sero-positive samples against AIV H9 were detected in Chitwan, Kapilbastu, Nawalparasi and Kaski districts. However, none of the samples was found to be sero-positive against AIV H7. All the samples positive against H5 were sampled in December 2008 exclusively (p< 0.001). In contrast, two samples collected before September 2008 and three samples after this time until January 2009 were sero-positive against AIV H9. Our findings indicate higher prevalence of AIV subtype H5 compared to H7 and H9 in duck species of Nepal.