This web site provides U.S. maps for reported outbreaks of 8 diseases down to the county level, with a breakdown of reported cases by month at the state level. The diseases mapped here are West Nile Virus, St. Louis Encephalitis, Western Equine Encephalitis, La Crosse Encephalitis, Powassan Virus, and both local and imported Dengue Fever.
Click on the disease name to see detailed U.S. maps, then click on a state for the county and monthly outbreak details. Each disease’s page has a link to background information on it with a brief description of the disease, and a link to historical maps with most going back to 2003. This resources is linked from
our Public Health GIS Resources page.