St. Louis Encephalitis incidence map
Source: Centers for Disease Control and Prevention,
National Notifiable Diseases Surveillance System


Curren, E. J. et al. American Journal of Tropical Medicine and Hygiene St. Louis Encephalitis Virus Disease in the United States, 2003-2017. Oct. 2018. 198 counties in 33 states and the District of Columbia reported SLEV activity.  A total of 193 human cases of SLEV disease were reported, including 148 cases of neuroinvasive disease. AK, AZ, and MS had the highest average annual incidence of neuroinvasive disease cases.