Geographers study why things are where they are.
Health or medical geographers specifically study why diseases appear in certain places, how they spread, and how they relate to environmental and social conditions.
Korine Kolivras, professor in the Department of Geography in the College of Natural Resources and Environment, observes spatial patterns and analyzes the underlying processes that create them.
Fifteen years ago, Kolivras, also an affiliated member of the Global Change Center, the Fralin Life Sciences Institute, and the Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, received a National Science Foundation grant to study the southward spread of Lyme disease into Virginia. Since then, the disease has continued moving south into North Carolina.
In 2021, an editor working on a book about diseases in Appalachia reached out to Kolivras about contributing a chapter.
Appalachia has unique environmental, cultural, and social conditions that make it distinct from surrounding areas. Her chapter explores Lyme disease in this region, as there has been little research on its spread in Appalachia.
“Lyme disease is associated with fragmented landscapes – patches of forests, farm fields, and nearby residences,” Kolivras said. “Unlike the suburbanization-driven spread seen along the East Coast, Appalachia’s land use has been shaped by resource extraction, including logging, coal mining, and now natural gas pipelines. My chapter serves as a first attempt to explore how these factors might contribute to the spread of Lyme disease in Appalachia.”
Outside Appalachia, Lyme disease has been strongly linked to suburbanization, especially in areas with large lots — homes on an acre or more — surrounded by patches of forest and open fields. This type of land use supports the animals involved in the Lyme disease cycle.
In contrast, Appalachia lacks widespread suburbanization. Logging creates small patches of deforested land that are later revegetated, or replanted. Surface mining has dramatically altered landscapes. Pipelines cut through forests, creating fragmented land.
“We don’t yet know if these changes support Lyme disease, but given the importance of landscape fragmentation in the disease’s spread elsewhere, there’s reason to investigate a potential connection in Appalachia,” Kolivras said.
Understanding the science behind it is important. Lyme disease is transmitted by ticks, which pick up the bacterium from host animals. The main reservoir, or source, for Lyme disease on the East Coast is the white-footed mouse. When a tick bites an infected mouse, it can acquire the bacterium. Later, if that tick bites a human, it can transmit Lyme disease. Notably, deer are not reservoirs of Lyme disease – they provide a bloodmeal to and transport the ticks that have the disease.
Kolivras had a few steps that people could take minimize the risk of the spread of the disease:
- Land development: Lyme disease thrives in fragmented landscapes with patches of forest, open meadows, and residences. If land is developed differently — reducing urban sprawl and maintaining more continuous forested areas, which support greater levels of biodiversity — spread of the disease could be reduced.
- Yard maintenance: Individuals can modify their backyards to be less hospitable to ticks. This includes keeping grass cut short, removing brush, and creating mulch barriers around yard edges.
- Personal protection: When outdoors, people should wear long pants and sleeves, tuck pants into socks, and conduct regular tick checks. Checking pets is also important because ticks can latch onto animals and later transfer to humans.
“We need more research to understand why Lyme disease is spreading into Appalachia,” Kolivras said. “Most existing studies focus on areas like Pennsylvania and New York, where Lyme disease has been present for decades. There’s far less research in rural, mountainous areas to the south. Since Lyme disease is typically associated with suburbanization, we need to investigate why it’s thriving in Appalachia, which is predominantly rural.”
– By Max Esterhuizen