The Oklahoma State Department of Health (OSDH) is reporting the first human infections in 2023, caused by West Nile Virus (WNV).
Over the last month, evidence of WNV activity has increased across the state and is now considered to be widespread. Positive mosquito pools have been identified in many regions of the state, and human infections have occurred in central, south central and southeast Oklahoma.
WNV spreads through the bite of an infected mosquito. In Oklahoma, WNV is primarily spread by the Culex mosquito, which feeds on infected birds and then spreads the virus when biting humans, horses, and some other mammals.
This type of mosquito increases in abundance during mid to late summer when temperatures are high, and the weather pattern is dry.
“We expect human cases of WNV every year,” said Jolianne Stone, the State Epidemiologist. “Typically, summertime is the beginning of the WNV season in Oklahoma, so with more people participating in outdoor activities there are increased opportunities for encountering infected mosquitoes.”
OSDH officials are reminding the public to take precautions to prevent mosquito bites as mosquito surveillance pools in the state show continued WNV activity.
Tips to avoid mosquito bites and prevent WNV:
• Use an insect repellent containing DEET, picaridin, or IR3535 on exposed skin and clothing when going outdoors, particularly between dusk and dawn when mosquitoes are more likely to bite. Insect repellent with permethrin should be used on clothing only.
• Repair or install window and door screens to keep mosquitoes out of the home.
• Prevent items such as buckets, cans, pool covers, flowerpots, children’s toys and tires from holding water to prevent providing mosquitoes a place to breed.
• Empty pet’s outdoor water bowl and refill daily.
• Scrub and refill bird baths every three days.
• Clean leaves and debris from rain gutters regularly to ensure they are not clogged.
While the vast majority of individuals with WNV will likely never experience symptoms following an infection, those with symptoms, are often mild and may include sudden fever, headache, and body and joint pain.
Recovery typically occurs within one to three weeks.
People older than 50 years, diabetics, or those experiencing uncontrolled hypertension are at a greater risk of developing severe neurologic disease from WNV infection. When the disease affects the nervous system, it can cause confusion or disorientation, loss of consciousness, paralysis, neck stiffness or coma.
Long lasting complications of WNV disease can include difficulty concentrating, migraines, headaches, extreme muscle weakness and tremors, and paralysis of a limb. There is no vaccine or treatment drug for this illness. The best defense is taking steps to avoid mosquito bites.
For more information on WNV, including historical reported cases, click here.
The Oklahoma State Department of Health (OSDH) protects and improves public health through its system of local health services and strategies focused on preventing disease. OSDH provides technical support and guidance to 68 county health departments in Oklahoma, as well as guidance and consultation to the two independent city-county health departments in Oklahoma City and Tulsa. Learn more at Oklahoma. gov/health.
