The<unk><unk>  encephalomyelitis virus is the causative agent of relatively uncommon viral disease<unk><unk>  encephalomyelitis <unk> . An alphavirus of the family Togaviridae, the<unk>  virus is an arbovirus (arthropod-borne virus) transmitted by mosquitoes of the genera Culex and Culiseta.<unk>  is a recombinant virus between two other alphaviruses, an ancestral Sindbis virus-like virus, and an ancestral Eastern<unk>  encephalitis virus-like virus. There have been under 700 confirmed cases in the U.S. since 1964. This virus contains an envelope that is made up of glycoproteins and nucleic acids. The virus is transmitted to people and horses by bites from infected mosquitoes (Culex tarsalis and Aedes taeniorhynchus) and birds during wet, summer months. According to the CDC, geographic occurrence for this virus is worldwide, and tends to be more prevalent in places in and around swampy areas where human populations tend to be limited. In the U.S.,<unk>  is seen primarily in states and Canadian provinces west of the Mississippi River. The disease is also seen in countries of South America.<unk>  is commonly a subclinical infection; symptomatic infections are uncommon. However, the disease can cause serious sequelae in infants and children. Unlike Eastern<unk>  encephalitis, the overall mortality of<unk>  is low (approximately 4%) and is associated mostly with infection in the elderly. Approximately 15–20% of horses that acquire the virus will die or be put down. There is no human vaccine for<unk>  and there are no licensed therapeutic drugs in the U.S. for this infection. The virus affects the brain and spinal cord of the infected host.
Western equine encephalitis virus
Sepik virus
Venezuelan equine encephalitis virus
West Nile virus
Cricket paralysis virus
California encephalitis orthobunyavirus
Rabies virus
Limestone Canyon virus