A LONG-TERM SEROSURVEY OF AVIAN INFLUENZA H5 AMONG WILD BIRDS IN NAKHON SAWAN PROVINCE, THAILAND

Abstract:  An outbreak of HPAIV H5N1 in Nakhon Sawan province, Thailand, in 2004 caused sporadic deaths of Asian openbill storks (Anastomus oscitans). An investigation was undertaken to determine if this virus occurs and circulates in wild birds in Nakhon Sawan province. Following the outbreak, a widespread serosurvey was conducted using the hemagglutination inhibition assay and microneutralization assay to detect antibodies against AIV H5. From 2007 to 2014, blood was collected from a total of 753 wild birds, representing 10 orders and 44 species. The results reveal that 10 serum samples were positive for AIV H5 antibodies. These seropositive results, found in the orders Ciconiiformes and Anseriformes, demonstrate that waterfowl serve as a reservoir host of AIV. Moreover, the seroprevalences in streak-eared bulbul showed habitat sharing with waterfowl or duck.