The state Health Department confirmed one case of West Nile virus on Thursday, bringing this week's number of cases to two.
Oklahoma is one of the states hit hardest by West Nile, breaking previous records of the number of cases and deaths reported.
This year, Oklahoma has had 175 confirmed cases of West Nile virus and 12 deaths. Before this year, the highest number of cases the state had seen was in 2007, with 107 cases and nine deaths.
Nationwide, there have been 4,725 reported cases this year, the highest number reported to the Centers for Disease Control and Prevention through the fourth week in October since 2003. About 70 percent of the cases have been reported from eight states: Texas, California, Louisiana, Mississippi, Illinois, South Dakota, Michigan and Oklahoma.
West Nile virus is a mosquito-borne illness not spread through human-to-human contact.
Most people who contract the virus either don't get sick or develop mild symptoms such as fever, fatigue and headache. People older than 50 are at the highest risk of developing serious complications related to West Nile virus, including paralysis and brain swelling.
The state Health Department recommends residents continue to wear long-sleeved shirts and pants when outdoors and use mosquito repellent. It's also important to remove stagnant water outside because it can serve as a breeding ground for mosquitoes.