Oklahoma health officials have reported the first human West Nile virus (WNV) cases in individuals in Okfuskee and McIntosh counties. No fatalities have been reported.

West Nile virus
Culex quinquefasciatus

Health officials say persons are at greatest risk of exposure to infected mosquitoes from July through October in our state.  Persons of any age can become ill after being bitten by an infected mosquito, but those over the age of 50 are at greater risk of developing serious illness involving the nervous system.

Over 80% of people infected with the virus never become ill.  If people do become ill, most cases are mild with symptoms such as a fever, headache, tiredness and body aches that go away on their own.  Some people may develop a rash on the trunk of the body.  In more severe cases, persons can develop meningitis or other neurologic disease.

Last year, Oklahoma reported 14 human WNV cases. Since WNV was introduced into Oklahoma, there have been 3 outbreak years – 2003 (79 cases), 2007 (98 cases/9 deaths) and 2012 (161 cases/15 deaths).

The Oklahoma State Department of Health advises use of insect repellents—particularly those containing DEET, picaridin, oil of lemon eucalyptus (PMD), or IR 3535—when enjoying outdoor activities like gardening, yard work, camping, or other leisure activities.  The type of mosquitoes that transmit WNV are most active during early morning and evening hours, so it is important to take mosquito bite precautions during that time of the day.  It is also recommended to drain or treat standing water around your home with a mosquito larvacide to reduce mosquito breeding sites.