The Oklahoma State Department of Health says doctors have diagnosed seven new cases of West Nile Virus in the state. That brings the total number of West Nile cases to 72 so far this year.
The new cases appeared in Bryan, Carter, Comanche, Marshall, Oklahoma and Tulsa counties.
Three Oklahomans have died this summer from the mosquito-borne disease.
The Centers for Disease Control and Prevention says 41 people have died across the country. The CDC called the current West Nile outbreak one of the largest ever in the U.S.
There have been 1,118 cases reported, and about half of them are in Texas.
OSDH warned milder temperatures and rain across the state could provide ideal conditions for mosquitos, raising the risk of bites and West Nile transmission.
"Oklahomans should not let their guard down when using insect repellent," said State Health Commissioner Dr. Terry Cline. "Now that our state's extreme heat has lifted, more Oklahomans are likely to seek outdoor opportunities to enjoy the milder temperatures."
Dr. Cline said August and September are peak periods for West Nile transmission in Oklahoma.