Prevention centers on controlling mosquitoes and avoiding mosquito bites. St. Louis encephalitis is a major mosquito-borne disease in the United States. It is one of a group of mosquito-borne virus diseases that can affect the central nervous system and cause severe complications and even death. Other similar diseases are eastern equine encephalitis, western equine encephalitis, and LaCrosse encephalitis. St. Louis encephalitis is caused by the St. Louis encephalitis virus, an arbovirus.
Arbovirus is short for ar thropod- bo rne virus .
In the United States, arboviruses are usually spread by infected mosquitoes. Birds are often the source of infection for mosquitoes, which can sometimes transmit the infection to animals and, in rare cases, people. St. Louis encephalitis is found throughout North, Central, and South America, and the Caribbean, but is a major public health problem mainly in the United States. The virus is found throughout the country, but periodic outbreaks and epidemics have occurred in the Mississippi Valley and Gulf Coast, the western states, and Florida. Humans and other mammals are not an important part of the life cycle of the virus.