The state Health Department on Thursday reported five additional cases of West Nile virus, bringing the total number of confirmed cases in the state this year to 160.
Oklahoma and the rest of the nation have seen a record-breaking number of West Nile virus cases this year.
West Nile was first identified in the U.S. in 1999. The previous worst year for the virus in Oklahoma was in 2007, when nine deaths and 107 cases were confirmed. There have also been nine deaths this year.
Thus far this year, the Centers for Disease Control and Prevention has reported 3,969 confirmed cases of West Nile virus in the contiguous United States. This is the highest number of West Nile virus disease cases reported to CDC through the first week in October since 2003.
People contract West Nile virus when they are bitten by an infected mosquito. The virus is not spread through human-to-human contact. Horses and birds are also susceptible to West Nile virus, along with some other livestock.
West Nile virus causes two separate types of illness: West Nile fever, and serious neurologic disease. Symptoms of West Nile fever include fever, headache, nausea, muscle weakness and body aches that usually last between two and six days, but sometimes longer.
Most people who contract the virus don't develop serious symptoms. About 20 percent of people infected with West Nile virus will develop a severe neurologic disease that could include paralysis and brain swelling. People older than 50 are most at risk of developing the more severe symptoms.
Public health officials recommend residents continue to use mosquito repellent when enjoying time outside and wear long sleeves and pants. Also, it's important to remove stagnant water from around your home, for it could serve as a mosquito breeding ground.
The mosquito population is expected to go into hibernation once Oklahoma gets its first freeze, which usually occurs around the first week of November.