Rare mosquito disease finds home in Tennessee, while mosquito season lengthens

KNOXVILLE, Tenn. (WVLT) - You’ve heard of West Nile, Zika, Malaria. They’re all diseases that come from mosquitoes.

But there are other mosquito carrying viruses impacting the children of Tennessee and Kentucky. With longer stretches of hotter weather in recent decades, the blood suckers are sticking around much longer.

With nearly three weeks of additional ‘mosquito days’ per year, based on weather data, two university of Tennessee experts told WVLT’s Ben Cathey that the longer season gives the bugs more time to infect us.

“It’s the number one pediatric ‘arbovirus’ in the country,” Dr. Becky Trout Fryxell said. An arbovirus is one spread by some pests like ticks, sandflies, or in our case, mosquitoes.

Dr. Becky Trout Fryxell is talking about something that we’d never heard of until a few weeks ago: LaCrosse encephalitis.

“I have a five-year-old kid going into kindergarten, so he’s of the perfect age to potentially contract LaCrosse Virus,” Dr. Trout Fryxell said.

While adults can get it, the impacts on children are much higher - including swelling on the brain.

“Trying to re-learn how to speak, maybe some mobility things, how to tie shoes and things like that,” Dr. Trout Fryxell said. “Potentially re-learning how to walk.”

East Tennessee is a hot-spot for LaCrosse. East Tennessee Childrens' Hospital said they’ve had dozens of cases the last several years - 55 since 2017. And the bugs are lasting longer into fall.

“But it’s very clear that it’s September and we still have mosquitoes,” Dr. Trout Fryxell said.

“And the more mosquitoes we have, the more potential for large-scale outbreaks of vector-born disease if it gets introduced,” Dr. Nina Fefferman said.

Dr. Nina Fefferman is a University of Tennessee mathematician who studies insect movements. and where disease like West Nile or the far worse Eastern Equine Encephalitis could arrive next.

Luckily “we haven’t had many cases,” Dr. Trout Fryxell said of Eastern Equine Encephalitis.

In 2019 there was a more-than sixfold increase of EEE cases across the country. Of that, 19 people died.

“Unfortunately with Eastern Equine Encephalitis, there is a high fatality rate,” Dr. Trout Fryxell said.

Around here, we haven’t seen many skeeters with Eastern Equine in their systems. But Dr. Fefferman said the extra few weeks are, well, a breeding ground:

“But if we don’t have a lot of disease already that can be transmitted to humans by mosquito bites, the number mosquitoes isn’t necessarily the problem. Having a longer window for mosquitoes actually makes it worse than just more mosquitoes,” Dr. Fefferman said. “But it does seem like, with our warmer temperatures, the mosquito season is longer.”

“That’s not great for either for mosquito control, or disease control.”

Both Knoxville scientists are trying to predict - like we do with the weather - where the disease-carrying mosquitoes will show up next.

“Just catch mosquitoes themselves and see how many are testing positive for diseases,” Dr. Fefferman said.

Even if you don’t feel the bite, experts say you should watch out.

“I don’t think people should overlook,” Dr. Trout Fryxell said. “We need to know that it’s here.”

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