A good spring rain, a forecast for honest-to-goodness hot weather for the week ahead and here come the mosquitoes and the ticks — right on the heels of news from the national Centers for Disease Control and Prevention noting a three-fold increase in vector-borne diseases from ticks, mosquitoes and fleas.
“Whenever it stops raining for five to 10 days, dump out that water in the kiddie pool, in the old tire, clean out the bird bath and reset before it starts raining again,” said Scott Meador, vector control program coordinator for the Tulsa Health Department. “This is definitely the time, and the ticks are out, too.”
While Meador prepared for mosquito testing, the CDC report hit the news with an added note that local health agencies are ill-prepared to deal with the increased threat. But the picture does not look so glum in Tulsa, according to Oklahoma statistics.
The county testing program that sets out mosquito traps and tests for presence of West Nile virus starts in a few days.
“Full-effect surveillance starts on Monday and Tuesday this week, and we’ll be reporting our first results on Thursday-Friday,” Meador said.
The national news this week — that vector-borne disease instances from mosquitoes, ticks and fleas have tripled in the U.S. since 2004 — should hit home with Oklahomans, who are all-too-familiar with ticks and mosquitoes and the sometimes fatal or life-changing diseases they can transmit.
The Centers for Disease Control fact sheet shows a low in 2004 of 27,388 incidents nationwide with the last peak in 2013 at about 60,000. In 2015 it dropped closer to 55,000 cases, but in 2016 the bar chart launches a skyscraper figure up to 96,075.
Even though two notable cases of new tick-borne diseases in the past decade have been documented in Oklahoma — Heartland and Bourbon viruses — in sheer numbers the vector disease situation described in the CDC report hits on problems not yet statistically large on Oklahoma’s horizon.
The jump in numbers is attributed primarily to Zika virus and Lyme disease outbreaks in other parts of the country. In Oklahoma the biggest issues still are West Nile (from mosquitoes) and Ehrlichiosis and Rocky Mountain Spotted Fever from ticks, said Tulsa Health Department epidemiologist Luisa Krug.
“In some years (the case count) goes way up and in some it goes way down,” she said. “It does seem to follow changes in environmental conditions year-to-year.”
The department works with the state Department of Health and other agencies on reporting requirements and looking out for unknowns, she said.
Just because Lyme and Zika are not huge statistics in the state as yet does not mean Oklahomans should not be wary. Zika cases have been documented in Oklahoma, and though they were always contracted elsewhere, that doesn’t mean it will stay that way, Krug said.
“We also like to think part of the reason for lower numbers some years is because of public education and outreach,” she said. “People are becoming better at protecting themselves, using repellents and wearing the right clothing.”
The hot, dry summer of 2012 was Oklahoma’s worst for West Nile virus with 161 cases, 15 of which were fatal, according to Oklahoma Department of Health reports. Within two years the cases dropped to 18, with zero fatalities. The 2017 count on West Nile virus was 38 with four fatalities.
“West Nile is very weather-dependent, and it happens conversely to the way a lot of people think about mosquitoes and wet weather,” Meador said. “We think of wet years as being bad for mosquitoes, and standing water does produce large numbers, but the Culex mosquito flourishes when we have hot, dry summers where the water that’s left gets nasty and stagnant. That’s when they thrive. That’s what they like.”
In focusing on how local agencies fall short in serving communities, the CDC report noted, “84 percent of local vector control organizations lack at least one of five core vector control competencies.”
Those five items: routine vector control, larviciding and/or adulticiding, routine surveillance, treating based on surveillance and pesticide-resistance testing.
Tulsa Health did indeed lack one item, the same one most others lacked, pesticide-resistance testing. Meador said he first heard about the need for those tests, which make sure the active ingredients in pesticides being used locally are still effective against species that might adapt, at a February training session.
“I went to training with the American Mosquito Control Association and learned of (the CDC) survey and that we need to be doing it,” he said. “Most departments didn’t realize they were supposed to be doing it.”
Meador said he has been in touch with Harris County, Texas officials in the Houston area who have the testing capabilities and said he may also work with Oklahoma City to bring that capability to Oklahoma health agencies.
“We are always looking to improve and to be one of the top-notch mosquito control agencies, at least between Dallas and Kansas City,” Meador said. “We always work to do what we need to do to be one of the best if not the best in our region.”