Abstract

West Nile virus (WNV) was first detected in the state of Georgia in the summer of 2001. Since then, dead bird surveillance, human and equine cases, and live bird serology have illustrated a nearly complete spread of WNV across the state. As amplifying hosts of WNV, avian species play an important role in the distribution and epidemiology of the virus. The objective of this study was to identify avian species that could serve as indicators for WNV over the physiographic and land-use variation present in the southeastern United States.

A total of 6,750 avian serum samples from birds captured throughout Georgia during the summers of 2002 and 2003 were tested by plaque reduction neutralization test (PRNT) for antibodies to WNV and a closely related Flavivirus, St. Louis Encephalitis virus. Four hundred and fifty of these samples were found positive for antibodies to WNV. WNV antibody positive Northern Cardinals (Cardinalis cardinalis) and Northern Mockingbirds (Mimus polyglottos) were distributed across all land use types and physiographic regions, with wetland areas being least represented. Positive Rock Doves (Columba livia) had high antibody titers against WNV; however, sampling sites for positive birds were not well-distributed across all physiographic regions and land-use types. Northern Cardinals appear to be the best indicators of WNV in the state of Georgia.