Saint Louis encephalitis
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![Human incidence of Saint Louis encephalitis in the United States, 1964-1998.](/Images/godic/202502/13/St_louis_encephalitis_map5402.PNG")
Saint Louis encephalitis is a disease caused by the Mansonia pseudotitillans mosquito borne Saint Louis encephalitis virus. Saint Louis encephalitis virus is related to Japanese encephalitis virus and is a member of the Flaviviridae subgroup. This disease mainly affects the United States. Occasional cases have been reported from Canada and Mexico.