Recent infection of West Nile Virus in horses from eastern Yucatán, Mexico

Objective. To determine the circulation of West Nile virus (WNV) in horses from the eastern Yucatán, Mexico. Materials and Methods. For convenience, 184 horses from 23 production units in the municipalities of Tizimín and Panabá, Yucatán, were studied. A blood serum sample was obtained from each studied horse and evaluated with an immunoglobulin M antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA) to detect immunoglobulin M (IgM) against WNV. Additionally, positive reactor and suspect serum samples were analyzed by reverse transcription polymerase chain reaction (RT-PCR) to detect viral RNA. Results. Eight studied horses were seropositive (4.3%, 8/184) to WNV and two were suspects (1.1%, 2/184). All serum samples were negative by RT-PCR. Conclusions. The detection of IgM specific against WNV in the studied horses shows recent infections with the virus and indicates its circulation in eastern Yucatán, Mexico.