Mosquito-borne disease cases reported in the U.S. 2016-2021, by disease
In the year 2021, there were 2,906 reported cases of West Nile virus, an increase from 730 cases in 2020. This graph shows the number of mosquito-borne disease cases reported to the National Disease Surveillance System in the U.S. from 2016 to 2021, by disease.