There have been 66 deaths so far this year.
More than 70 percent of the cases were found in Texas, South Dakota, Mississippi, Oklahoma, Louisiana, and Michigan. 45 percent of those cases were in Texas.
The Chicago Department of Public Health is taking measures to protect residents from the mosquito borne illness.
Mosquito killing chemicals were sprayed in several Chicago neighborhoods last night in effort to kill mosquitoes that may carry the virus.
Crews drove through Archer Heights, Brighton Park, West Elsdon, Gage Park, Montclare, Belmont Cragin and Austin Wednesday night, spraying an ultra-low-volume of insecticide.
Health officials say there is far more West Nile activity in the city now, than this time last year.
In Illinois, there are 45 confirmed cases of the West Nile virus. Eight cases are in Chicago.
There have been two deaths in the state.