OKC area still at risk for West Nile heading into Labor Day weekend
Oklahoma City — Summer may be coming to its unofficial end, but mosquitoes could stick around and spread disease for a month or longer, according to health officials.
The Oklahoma City-County Health Department's ‘Skeeter Meter' shows the risk of getting West Nile virus is still on the high side of the normal range, said Eric Howard, the department's epidemiologist. The department tries to gauge risk based on temperatures, resident complaints about bugs, how many mosquitoes it traps and whether those trapped mosquitoes test positive for West Nile.
Oklahomans don't have to worry about tropical mosquito-born illnesses like Zika and dengue, because the species of mosquito that carries them doesn't live in the state, Howard said.
People who plan to spend time outdoors this weekend should wear long sleeves or use bug spray with DEET, Howard said. Though summer is winding down, mosquitoes typically don't die off until temperatures consistently fall to the 40s, he said.
“People are going to be wearing shorts and mosquitoes are going to be biting people,” he said. “We'll sometimes get West Nile virus reports up to and including October.”
About 80 percent of people infected with West Nile don't know they have it, and most of those who do get sick develop flu-like symptoms that get better with rest, fluids and over-the-counter pain relievers. One in approximately every 150 infected people develop serious neurological symptoms, however. Those symptoms can include seizures, paralysis or delirium, and some people fall into a coma, according to the Centers for Disease Control and Prevention.
“It can be quite severe, and that's why we want to make people aware,” Howard said.
The CDC had collected 29 reports of West Nile in humans in Oklahoma as of Monday.
The National Weather Service predicts Oklahoma City will stay dry through Friday, with a small chance of showers this weekend. That could possibly work in the mosquitoes' favor, however. A downpour, like Oklahoma City saw Friday, can wash eggs away or drown mosquito larva. Mosquito numbers tend to increase a week or two after a rain, because the eggs do best in stagnant water, Howard said.
That makes it important to check your property for anything that could hold rainwater and any openings in screens that could let mosquitoes through, Howard said. People who have elderly neighbors also should offer to help empty stagnant water, because older people are at a higher risk of severe complications from West Nile, he said.
“It can be as small as a bottle cap of water that mosquitoes will lay their eggs in,” he said.
Oklahoma City does have one advantage this week: forecasts suggest it will be a relatively cool weekend for late summer, with highs in the 80s. The risk of West Nile is highest when temperatures climb above 93 degrees, Howard said. Higher temperatures cause mosquitoes to mature faster, so they can bite people for longer, and reduces the incubation period before they can spread the virus, according to a 2012 article in the American Journal of Tropical Medicine and Hygiene.
“The hotter it is, the more active the virus becomes,” he said.