This story was produced in collaboration with Climate Central. It also received support from the Pulitzer Center.
Southwest Virginia is a hotspot for tick-borne disease—with some of the highest per-person rates of Lyme disease in the state. That rise has happened over the past 20 years.
At a public health fair in Roanoke, Jenny Hall holds up a plush version of a blood-sucking mite. “Have you ever seen this?”, she asks two students visiting her table, which is covered with displays and handouts in multiple languages. Hall is a public health expert at Radford University and founder of the website Ticks in Virginia. This event is put on by a nonprofit called Blue Ridge Literacy that teaches adults English.
One of the students visiting Hall’s table guesses, “Spider?”
“No,” Hall smiles. “Tick. T-I-C-K.”
“Oh, OK,” the two students nod. “Tick.”
These advanced English students, Casimir and Wislet, have learned an important vocabulary word in Southwest Virginia, which is a hotspot for tick-borne disease—with the highest per-person rates of Lyme disease in the state. Tick-borne disease education is Hall’s mission. In particular, residents from other countries often do not know basic tick prevention information or have the language to talk with their doctor. Hall says, “If they can go into the doctor with symptoms and say, ‘tick,’ there's going to be a better chance of getting a diagnosis.”
The outcomes following a Lyme disease diagnosis are worse for racial and ethnic minorities. A Lyme rash is harder to see on a person with darker skin, and if a patient doesn’t even know to ask a doctor about a tick bite, they will struggle to get the help they need. And there’s more that Hall wants these students to know. “In Virginia, we have many ticks all year long,” she explains. “Summer, many more. But in the winter, this black-legged tick is common.”
“In the winter? What?!” Casimir exclaims.
“Yes, if it’s not freezing, they can come out,” Hall says.
Like Casimir and Wislet, many residents are surprised by the number and seasonality of ticks these days. That’s because the number of ticks and the diseases they carry are on the rise. In addition to Lyme disease, ticks in Virginia can transmit 11 other diseases—and counting. Hall recently presented to an older audience at the Rotary Club in Salem that hadn’t fully comprehended this rapid increase in tick-borne diseases. Hall recalls, “They're like, ‘we've had ticks here our whole lives, what's going on now that is different?’” She responded, “Although people in the past may have had a lot of different tick bites and never had an issue, there was less of a chance to get a tick-borne disease.”
Scientists do not fully understand why this increase has happened, but they’ve got some clues. The story is complex, starting centuries ago. Jory Brinkerhoff is a biologist at University of Richmond and has been studying this change. Brinkerhoff says, “Deer populations shrank dramatically up until 100 years ago. As deer populations have come back, tick populations have followed.”
Near one place that remnant deer herds had survived, Lyme disease was discovered: in Connecticut in 1975. Black-legged ticks and Lyme disease have been expanding ever since. Climate change is exacerbating that expansion, because longer warm seasons are especially good for ticks. More ticks mean more tick-borne disease. As those ticks from the Northeast reached Virginia in the 2000s, they have especially congregated along the Appalachian Mountains. Brinkerhoff says, “We've made maps of Lyme disease incidence year over year, and you can sort of see the steady march down the mountains, starting around 2005, right? So up in Loudon and Fairfax, you've always had Lyme disease, and then it kind of slowly spills down through Albemarle, Nelson, and then into Southwest Virginia.”
Brinkerhoff’s research shows that mice in southwestern Virginia in the 1980s and 1990s didn’t commonly encounter Lyme disease. And human cases were also unusual. Brinkerhoff says, “Going back 20, 30 years ago there were very few tick-borne disease cases in humans. Into the early, mid 2000s, that's when things started to percolate and it's just blown up since then.”
Untangling all the factors at play is no easy task. But prevention is possible. Experts recommend wearing bug repellent, treating outdoor animals, and doing daily tick checks. Mowing grass regularly and treating wild deer and mice with pesticides also help. Most of this advice addresses individual behavior, even though the increase in tick-borne diseases is a landscape phenomenon related to land use, climate and wildlife ecology.
But there’s one landscape-level solution that has not received nearly enough attention, and that’s where Elizabeth Gleim comes in. Gleim is a biologist at Hollins University near Roanoke. When she and three field techs were working in Georgia to study tick numbers on a forested site that had been regularly burned, they couldn’t find any. Gleim explains, “After a month of fieldwork, we had caught one tick across the entire 28,000-acre field site, and that is when I realized we had completely underestimated the power of fire.” Gleim had to broaden the study area to have enough ticks for comparison.
“We found that, yes, if you're in an area that's burned on a long-term, regular basis, you're not going to have ticks,” Gleim says. “But also if you're in an unburned area that is surrounded by burned area, you're also not going to have ticks. That highlighted the far-reaching effects of prescribed fire.”
How effective fire is in keeping tick numbers low in Southwest Virginia has not been studied yet. Tick numbers can bounce back quickly after fire, and so regular burning that opens up the canopy and dries out the ticks below seems key to the success on Gleim’s field sites in Georgia. Nevertheless, Gleim thinks this technique could help here, too—we just don’t know how much, unless someone funds the research to find out.
Of course, most of us aren’t in a position to do regular, controlled burning on the forests and fields around us, or treat all the animals in an area with tick pesticides. Although several Lyme disease vaccines are in clinical trials, they aren’t out yet, and there aren’t vaccines for the other tick-borne diseases. So, for the time being, we prevent what we can.
That’s why Hall is at the public health fair, making sure an especially vulnerable population knows the basics. She goes on to show Casimir, Wislet, and many of their classmates how to remove a tick if it bites them. She has a foot model made of a rubbery material, which people use to practice removing attached fake ticks. Hall helps the students use pointy tweezers to grab the model tick’s head and pull it out, so that the whole tick is removed without squeezing its pretend stomach contents back inside the host.
“Yep, straight up and out,” she encourages.
Hall passes out handouts about tick diseases, as well as magnifying glasses and free samples of bug repellents. The students pepper her with questions; many have had no idea of the risks of tick-borne diseases in this area.