West Nile encephalitis virus is a virus that is transmitted by mosquitoes and can cause severe neurological symptoms. There are several synonyms for this virus, including West Nile virus, West Nile fever, and West Nile neuroinvasive disease. The virus is named after the West Nile region of Uganda, where it was first isolated in 1937. Since then, the virus has spread globally and has caused outbreaks in countries throughout the world. While many people infected with the virus do not experience any symptoms, others may develop a fever, headache, body aches, and fatigue. In severe cases, the virus can cause encephalitis, which can lead to permanent neurological damage or death.