Mosquitoes testing positive for West Nile virus were discovered in Anaheim and Garden Grove, the Orange County Mosquito and Vector Control District reports.

The infected mosquitoes have been located in several city neighborhoods, including Old Louisville, Irish Hill, California, Iroquois and Churchill Downs, officials said July 22. This follows mosquitoes testing positive for the virus in the Tyler Park and Highlands neighborhoods earlier this month.

There have been three human cases of West Nile Virus in California this year, with one fatal case, according to the California Department of Public Health.