St. Louis encephalitis is a viral disease spread by infected mosquitoes. This disease can affect the central nervous system, causing severe complications and even death.

The Central Nervous System
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A virus with the same name causes St. Louis encephalitis. Mosquitoes are infected with this virus when they feed on birds. Infected mosquitoes can transmit the virus to humans and animals. St. Louis encephalitis is not spread from person to person.