FIGURE 1.
Percentage of West Nile virus disease cases,* by week of illness onset — United States, 2009–2018
* N = 21,869.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.