Conversation in the vector control room at Tarrant County Public Health is punctuated by the awestruck murmurs of five people who love their work. 

Their exclamations come in oohs, awws and Latin. Faces snug in microscopes, they marvel over blue scales on Uranotaenia sapphirina, a mosquito that feeds on earthworms, or Psorophora cyanescens, a mosquito dappled with purple and white.

Beneath the microscope, the view is iridescent — like a “disco ball,” according to Bethany Hambrick, a vector control specialist who’s been on the team for five years. Some mosquitoes can be drab; others are “absolutely gorgeous.”

There’s also the click-click-click from a machine that counts insect bodies as they’re sorted in petri dishes marked by grids that look like bingo cards. Once they’ve sorted and counted mosquitoes, Hambrick and her colleagues bottle a sample up like wine to send to North Texas Regional Laboratory for testing. 

Bethany Hambrick sorts and counts mosquitoes in a petri dish in the vector control room at the public health department. (Photo courtesy of Brian Murnahan | Tarrant Count Public Health)

The strange beauty of their work belies its serious intent: preventing the spread of mosquito-borne viruses in a community already exhausted by COVID-19. Last year, Tarrant County experienced a West Nile epidemic — and hardly anyone noticed except the more than 40 people confirmed positive and the families, friends and colleagues of the six who died. 

Those cases only scratch the surface; in peak weeks last summer, close to 60% of the team’s mosquito samples were positive for West Nile virus, according to Nina Dacko, who supervises the team. That percentage is “insane,” she said. So even though the number of human cases was relatively high last year, it’s still an undercount. 

“We had a lot of human cases that we’ll never know about because people weren’t going to the doctor,” she said.

By mid-August this year, the public health department had announced only one West Nile case — a person over 65 who contracted the most serious illness from the virus, a neuroinvasive disease that can mimic the effects of stroke. After a “heavier” year like last one, Dacko thinks this year will be mild. The team remains alert, reading patterns in the data, collecting samples and learning from the bugs they trap. By nightfall, they’re treating mosquitoes around the county with insecticide to slow the spread. 

“Even though you’re not seeing us do the work, know that we are there,” she said. “And we’re eliminating as many mosquitoes as we can find.”

The team’s duties undergird their title. A vector is an organism that can transmit disease from one living thing to the next. Vector control, then, means the team works to contain the spread of vectors — in this case, mosquitoes.

Dacko’s team at the county health department collaborates with public health specialists across the county to trap some of the more than 45 species of mosquitoes in the county. 

Then, the five-person team counts and identifies the mosquitoes before sending a batch to the regional laboratory to determine if the mosquitoes that can carry a specific virus — like Culex quinquefasciatus, or the southern house mosquito, carries West Nile — are infected. 

The mosquito itself transcends genre. It’s one of the reasons why Hambrick was drawn to them in the beginning. She took an insect biology class in college that redirected her life path.

“I’m fascinated at how evolutionarily adaptive they are,” she said. “They are able to breed and live and survive in so many different places throughout the world. I’m serious, it just blows my mind.”

Learn about the females, and they feel almost vampirish; they require a “bloodmeal” to provide protein for their offspring. Learn about their eggs, which can lie dormant for years only to pop out of the ground like cicadas or robots, and it’s science fiction. Hundreds can develop within a single bottle cap of water over time. 

Mosquitoes start their lives in the water, only to emerge airborne when development and metamorphosis are complete. Some can travel for blocks; others hundreds of miles. 

“A lot of people say, ‘A mosquito is a mosquito is a mosquito.’ And that’s not necessarily the case,” Dacko said. “Once you start learning about them, they occupy all these different niches all over the place.” 

For example, one mosquito from the Deinocerites genus “only grows in the holes left in the seashore by crabs,” she said. Thus its nickname: crabhole mosquito.

“You can never really stop learning,” Dacko said. “And I think that’s also something else I really loved about the field.”

As a little girl, Dacko adored bugs — especially collecting and identifying them. She tucked her enthusiasm away in high school to avoid becoming “the weird girl who plays with bugs,” instead pursuing performance piano. In college, her love for them returned; she considered becoming a forensic entomologist, someone who studies the way bugs interact with a body at a crime scene. 

It’s a specialty that can “help someone get justice,” she said, a reflection of how her work currently intersects with public health: “There’s a connection between being fascinated with bugs and then helping people in the long run.”

West Nile virus was discovered in the U.S. in 1999 after people started getting sick in New York City. Birds, too, were sick; even exotic birds like flamingos were dying at the Bronx Zoo. 

It works like this: Birds experience their own epidemics. Mosquitoes like Culex quinquefasciatus feed on the birds, some of which are infected. Then, those same mosquitoes feed on us. Russ Jones, the chief epidemiologist at Tarrant County Public Health, calls them “promiscuous.” 

Vector control specialist Bethany Hambrick pronounces Culex quinquefasciatus, the type of mosquito that carries West Nile virus.

When a mosquito “bites” someone, it sticks a needle in their skin and injects saliva, which contains an anticoagulant to stop blood from clotting, therefore enabling it to flow. Sometimes, that saliva contains West Nile virus.

Most people who get West Nile don’t know they have it. The symptoms are mild, non-existent maybe, and go away on their own. Also, people can’t transmit West Nile to each other — they’re “dead-end hosts,” Jones said. 

Still, the same people most vulnerable to COVID-19 can get deeply ill from West Nile: people who are immunocompromised or elderly. If they become infected, they’re more likely to develop inflammation in the brain, Jones said. They can lose their ability to walk or swallow. Their personalities may change. Recovery can take years. Some will die. 

“A lot of those cases are people who have to relearn how to walk, how to talk, how to eat, maybe will not have full function of motor skills for the rest of their lives,” Dacko said. “Just because someone doesn’t die doesn’t mean that it wasn’t a serious impact on their life.”

The initial diagnosis usually involves a blood test. A person with COVID-19 or West Nile could experience fever, body aches and headaches, Jones said. The tell-tale difference is the loss of taste and smell for people with COVID-19. That overlap may contribute to cases of West Nile going undetected. 

“Everyone’s getting screened for COVID,” he said. “Let’s say you did get a fever, and you did have body aches, and you went through a community drive-through. And you got your test results: COVID-19 negative. There’s no physician there to go, ‘Well, let’s look at something else.’”

Ask the vector control team:

What’s one of your favorite things about mosquitoes?

“How incredibly specific their feeding and habitat preferences can be. It is awesome that there are mosquitoes that only breed in one species of pitcher plant and others that take a bloodmeal from earthworms.”

Daniel Brewer, vector control specialist

“The contrast. You have an animal that is at the base of the food chain, and yet is one of the deadliest animals for people and other large mammals.”

Joe Carr, vector control specialist

“They occupy such a different variety of niches in our ecosystem. As a collector of things, I’m fascinated by how different each species are from one another.”

Nina Dacko, vector control supervisor

“I’m fascinated at how evolutionarily adaptive they are,” she said. “They are able to breed and live and survive in so many different places throughout the world. I’m serious, it just blows my mind.”

Bethany Hambrick, vector control specialist

“They allow me to have a steady and interesting job. It’s a love/hate relationship. I hate that mosquitoes cause disease, but love that they allow me to work in the field of biology and nature.”

Shannon Solberg, vector control specialist

Hambrick said she wants to put out a “giant PSA” to medical care providers: Test patients for viruses like West Nile. Or, patients can ask for a West Nile test.

If a person does test positive for West Nile, treatment can be as simple as over-the-counter pain medication or, if they’re seriously sick, hospitalization. No vaccines exist for West Nile virus.

And West Nile isn’t the only mosquito-borne virus to consider, Jones said. There’s also Zika, dengue and chikungunya that exist around the world. Part of the vector control team’s role is to educate people about how to protect against all of them, whether at home or traveling.

The team recommends people think about “the four Ds,” Dacko said: Mosquitoes mostly emerge during dusk and dawn, so people should dress in long sleeves and pants, use DEET as repellent and, finally, drain standing water. 

“For all disease, behavior plays a huge component,” Jones said. Depending on what a person is doing, they may need to protect against mosquitoes and COVID-19.

“I’m thinking, wow, a person dressed in long sleeves, pants, wearing a can of DEET or Off on their belt with a mask on,” Jones said. “It almost feels that way.”

Still, he said he’s spoken to “enough folks on both diseases who’ve lost loved ones,” and the protection efforts are worth it. 

Adding levity to the severity of viral outbreaks is the vector control team.

“The best part about our team is that we are all equally nerdy,” Hambrick said. 

They’ve added houseplants and succulents to their room at the county health department, some draped over bookshelves of entomology tomes. 

“It’s just a haven of science, especially biology,” she said. “And we’re all really happy, lovely people.” 

They share not only a love of science, but a common language with which to discuss it — be it in English or Latin. 

“When you have people that communicate the same way you do and feel the same way  about the world, nature, and life, then just come to work and do your best every day and enjoy the time that you have with each other,” Hambrick said. “If you can do that, then honestly, your job’s going to be great.”

Alexis Allison is the health reporter at the Fort Worth Report. Her position is supported by a grant from Texas Health Resources. Contact her by email or via Twitter. At the Fort Worth Report, news decisions are made independently of our board members and financial supporters. Read more about our editorial independence policy here

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