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Climate Change Could Make Missouri A Mosquito Paradise, But Health Experts Warn We Aren't Ready

Sep 9, 2019

This year's catastrophic flooding has created hard times for many people in Midwest, but it's created a nirvana for mosquitoes.

Kansas City and the surrounding region could potentially become a hotbed for mosquito-borne viruses like West Nile virus in the coming years due to increasing temperatures and more frequent flooding, which are predicted by climate experts.

“Once that flooding [subsides], and you get lots of standing pools of water, then the mosquito populations can really thrive, and you see a real big increase in both the populations and then, in some cases, a disease if there’s a pathogen circulating in the area,” says Cory Morin, an acting assistant professor specializing in zoonotic diseases and environmental health at the Center for Health and the Global Environment at the University of Washington.

Some health experts, however, warn that Missouri isn’t prepared to deal with the diseases that they may bring.

West Nile virus arrives

West Nile virus, which first appeared in the United States 20 years ago, is already being reported in the Midwest this year, even before the season for it typically begins.

Though mosquitoes are typically regarded as little more than nuisances, a single bite changed the life of Rebecca O’Sullivan.

“I lost the ability to count,” O’Sullivan says. “I couldn’t do basic addition and subtraction.”

Rebecca O'Sullivan of Wichita, Kansas, had to leave her job after contracting West Nile virus in 2012.
Credit ALEX SMITH / KCUR

In late August of 2012, when O’Sullivan was 38, she hosted a small party outside at a country club in Wichita.

She says she just had a single glass of wine, but she woke up with what felt like the worst hangover imaginable.

“I had severe light sensitivity,” O’Sullivan says. “My head hurt so bad I couldn’t raise it. I couldn’t even lay there. It was pretty brutal.”

She was initially diagnosed with the flu, but a week later, her doctor called saying she tested positive for West Nile virus, a disease carried by mosquitoes.

By then, her illness had gotten much worse. She was exhausted and at times unable to move her limbs.

She developed narcolepsy, had seizures and became depressed.

“I just remember thinking I’m going to collapse at work,” O’Sullivan says. “If anything will kill me, it’s going to be trying to do this, and I can’t do it anymore.”

O’Sullivan had to leave her job in aerospace engineering, but it wasn’t until several years later that a neurologist discovered that the virus had caused meningoencephalitis.

O’Sullivan’s case is extreme and very rare. Only about 1 in 150 people with West Nile Virus develop severe symptoms. About 80% have no symptoms.

Climate change could worsen the problem

Climate experts say that, along with flooding, parts of the Midwest could also see more drought, or possibly cycle between flooding and drought.

In northwest Missouri, corn and soybean fields remain flooded months after the year's heaviest storms.
Credit ALEX SMITH / KCUR

Morin says this, too, could lead to more disease.

“With something like West Nile Virus, drought can be important if it means that bird species, which are the hosts for the virus, come into a lot more contact with mosquito species ‘cause there’s a lot less water sources for them to share, and because of that, they congregate in these small areas, and there’s a lot of opportunities for transmission between mosquito and the birds,” Morin says.

Increasing temperatures can also lead to more mosquitoes, and that may already be happening. Since the 1980s, the mosquito season in Missouri has increased by at least 18 days, according to Climate Central, a nonprofit news and research organization.

But experts have limited information about what mosquitoes and diseases are currently active in the state.

A low-risk strategy

In 2017, the National Association of County and City Health Officials released survey data from health departments across the country about their competencies to do things like testing for mosquito types or controlling for mosquitoes, based on guidelines from the federal Centers for Disease Control and Prevention.

The group found that almost no local health departments in Missouri met basic requirements. The same was true in Kansas and other Midwestern states, including Arkansas, Iowa and Nebraska.

For the past few years, entomologist David Claborn of Missouri State University has conducted mosquito surveillance in Springfield, Joplin and other urban parts of the southern half of the state.

He explains that, so far, his work has shown low disease risks compared to hotspots like Florida or Louisiana. The approach of state and local health departments reflects that.

“Up here, I think most people, they kinda find out where the problems could be,” Claborn says. “If there’s an outbreak of disease, they have a plan set up to bring in contractors to handle mosquito control on an as-needed basis.”

Claborn acknowledges that his surveillance doesn’t rule out diseases in the state, however, and as the outlook for mosquitoes continues to change, experts say Missouri’s approach isn’t enough to stay on top of the problem.

“The key with addressing these particular illnesses is to be proactive,” says Dr. Oscar Alleyne, epidemiologist with the National Association of County and City Health Officials, based in Washington DC.

Lanny Franks, a fifth generation farmer from Rushville, Missouri, says this year's flooding is as bad as he's ever seen.
Credit ALEX SMITH / KCUR

Alleyne says if cities and counties don’t do this work, there’s only so much a state can do to prevent these diseases from taking hold.

“In a true, comprehensive response, it’s a local activity that needs to have that strength and support in order for us to be successful,” Alleyne says.

A lack of resources

Alleyne says some Midwest health departments have stepped up their game, and others have managed to maintain strong mosquito program since the early years of West Nile virus.

Nebraska, for example, produces weekly reports on mosquito types and diseases found in its counties.

But none of the health departments in the Kansas City area currently track mosquitos or do regular mosquito control. That includes health departments in Kansas City, Missouri, and Jackson, Cass, Platte and Clay counties in Missouri, and Johnson and Wyandotte counties in Kansas.

Jackson County Health Department spokeswoman Kayla Parker explains that the reason is simple.

“We actually just don’t have the local resources to do a program like that,” Parker says.

State-level efforts in Missouri have been stretched thin, too.

After West Nile appeared, Missouri received about half a million dollars a year for work on mosquitoes from the federal Centers for Disease Control and Prevention.

Today, outside of some occasional federal grants for Zika and state funding that pays for Dr. Claborn’s work, the health department’s annual mosquito budget averages $160,000.

Dr. Alleyn says that, even if reports of a disease outbreak led to more funds for state and local health departments, these agencies would be unprepared and unable to help people affected by it.

“By that time, you’re guaranteed to be toward the end of the mosquito season, and the ability to be comprehensive and proactive before that happens has been totally lost, and at best, you can only wait till the next season to try to minimize it,” Alleyn says.

West Nile virus season in the Midwest typically runs from about mid-August through late September.

Rebecca O’Sullivan says this time of year makes her anxious.

She now works to support others with the virus and has started doing advocacy to try to get neighbors and health officials to take the risks of mosquito viruses more seriously.

Seven years after contracting West Nile virus, she still struggles with health and cognitive problems, although today, she’s made some peace with her condition.

“The difference is, I know that I’m going to be around tomorrow. It might be a little bit better. It could be worse, but it’s going to be different,” O’Sullivan says. “And I’ve got to live the best life I can.”

Alex Smith is a health reporter for KCUR. You can reach him by email at alexs@kcur.org.