First human cases of West Nile Virus this season reported in Oklahoma

The Oklahoma State Department of Health is reporting the first three human cases of West Nile Virus for the season. The cases have been confirmed in residents of Canadian, Grant and Tulsa counties.

Summertime typically marks the beginning of the WNV season in Oklahoma, with outdoor activities providing opportunities for encountering infected mosquitoes. Health officials are reminding the public to take precautions to prevent getting bitten by an infected mosquito.

WNV is spread through the bite of the Culex mosquito, which feeds on infected birds and transmits the virus when biting humans, horses and some other mammals. This type of mosquito increases in numbers during mid to late summer when the temperatures climb and the weather pattern is dry. Health officials expect the number of cases to increase as the temperatures rise throughout the summer.

The OSDH provides the following tips to avoid mosquito bites and to 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, flower pots, children’s toys and tires from holding water so mosquitoes don’t have a place to breed.
• Empty a 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.

Symptoms of WNV vary widely depending on a person’s risk for more severe disease that involves the central nervous system. Some may experience sudden onset of fever, headache, dizziness, and muscle weakness and recover within one to three weeks while others develop life-threatening meningitis or encephalitis causing confusion, stupor, paralysis or a coma.

Long-lasting complications of WNV disease can include difficulty concentrating, migraine headaches, extreme muscle weakness and tremors, and paralysis of a limb. Those older than the age of 50, diabetics, or those suffering from uncontrolled hypertension are at greater risk of developing severe neurologic disease from WNV.

There is no vaccine or treatment drug for the illness, so taking steps to avoid mosquito bites is the only defense.

For more information, visit the OSDH website at westnile.health.ok.gov.