Another Climate Change Risk – Lyme Disease

We’ve always had ticks in West Virginia. But maybe you’ve noticed they’re worse now. You aren’t imagining it. There are more ticks these days and they are showing up earlier in the spring and dying off later in the fall. The culprit? Climate change.

As climate change brings warmer spring temperatures and milder autumns to the northeastern United States, blacklegged ticks (deer ticks) are emerging earlier and feeding longer.

Blacklegged ticks have a 2-to-3-year life cycle. During this time, they go through four life stages: egg, larva, nymph, and adult. After the egg hatches, the larva and nymph each must take a blood meal to develop to the next life stage, and the female needs blood to produce eggs. Deer are usually the source of this meal, but you can be if you’re not careful.

Larval and nymphal ticks can become infected with Lyme disease bacteria when feeding on an infected wildlife host, usually a rodent. The bacteria are passed along to the next life stage. Nymphs or adult females can then spread the bacteria during their next blood meal.

Nymphal ticks pose a particularly high risk due to their abundance and small size (about the size of a poppy seed), which makes them difficult to see. Lyme disease patients are often not even aware of a tick bite before getting sick. Nymphal ticks are most active from April through July.

The CDC did a study measuring the cost of Lyme disease to society and to each Lyme disease patient as of 2016. In that year, the average treatment cost to patients was $1,200 and the average cost to society of each case was $2,000. These costs are much higher in today’s dollars.

Lyme disease is really becoming a problem in West Virginia. The CDC keeps track of reported Lyme disease cases by state. In 2008, the CDC reported 135 cases in West Virginia. In 2022 that number was 2,470.

Many people think of climate change as merely a problem of heating the planet, but that heating has repercussions in ways we never anticipated. The spread of ticks and Lyme disease is one of them.