Togaviruses Causing Encephalitis

The virus family Togaviridae comprises two genera: Alphavirus and Rubivirus. Encephalitic alphaviruses are neuroinvasive and cause neurological symptoms in various animals and humans. Western equine encephalitis virus is distributed in the US from the mid-western states of Michigan and Illinois to the west coast and in western Canada, whereas Eastern equine encephalitis virus is distributed from Texas to Florida along the Gulf coast and from Georgia to New Hampshire along the Atlantic Coast and in eastern Canada. Transmission of Venezuelan equine encephalitis virus occurs predominantly in Central and South America, with the exception of Everglades virus, which is found in Florida, and Bijou Bridge virus, found in western North America.