West Nile Virus in Horses—Not Gone and Should Not Be Forgotten

West Nile Virus in Horses—Not Gone and Should Not Be Forgotten

West Nile virus is transmitted by mosquitoes. | iStock  Over the last two decades, West Nile virus (WNV), an orthoflavivirus transmitted by mosquitoes, has become endemic on all continents except Antarctic and continues to be a major threat to the health and well-being of both horses and humans. The virus had an explosive emergence in North America in 1999, followed by rapid expansion throughout the U.S. and parts of Canada over the first five y…