St. Louis Encephalitis is a viral infection that affects the brain, primarily transmitted through the bite of infected mosquitoes. It is caused by the St. Louis Encephalitis virus, which is part of the flavivirus family. Symptoms can range from mild flu-like signs to severe neurological issues, including confusion, seizures, and even coma in extreme cases. The disease is most common in the United States, particularly in the central and southern regions. While many people infected with the virus may not show symptoms, those who do can experience serious complications. Prevention focuses on reducing mosquito exposure through the use of repellents and eliminating standing water where mosquitoes breed.