Global Warming, Ticks, and Lyme Disease

Is climate change causing an infestation of ticks?

Yes, scientists say. So if you’re thinking of hunting, trekking, hiking, camping or going on some other outdoor activity this summer, take extra precautions. The United States Centers for Disease Control warns that the tick population is expected to pose a far greater threat of Lyme disease transmission this spring.

Researchers at the Cary Institute of Ecosystem Studies in Millbrook, New York also warn that people heading into the woods this spring in the Northeastern states will be at higher risk than usual of coming down with Lyme disease as insect populations are expected to swell after the warm, mild winter.

Over the past 30 years, cases of Lyme disease have spiraled from a few hundred to 30,000 reported each year — with 90 percent of them occurring in the Northeast — Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont, New Jersey, New York and Pennsylvania.

A bacterial infection from a bite of an infected tick, Lyme disease symptoms typically show up within three to 30 days of the bite. The first sign is usually a circular rash that looks like a bull’s eye.

As the infection spreads, you may have fever and flu-like symptoms. And while treatments are generally effective, if the disease isn’t treated early with antibiotics, it can lead to long-term, recurrent arthritis, cause chronic fatigue and term neurological problems.

After days of unusually high temperatures in March, U.S. health officials are warning residents of Maryland and Virginia — further south from the Northeastern states — to also be vigilant for ticks and to protect themselves from the threat of Lyme disease, the Associated Press reports.

People who are venturing into areas with thick undergrowth should wear light-colored clothing to make the bugs easier to spot, advises public health entomologist Eric Dotseth. He also suggests that people examine themselves and their pets thoroughly because the black-legged tick that carries Lyme disease –previously known as the deer tick — is tiny and hard to find.

Ticks can attach to any part of the human body — including hard-to-see areas such as the groin, armpits and scalp. “They are cueing in on things like heat, carbon dioxide, motion, sweat — all of these things that suggest a living, breathing, vertebrate host,” he tells AP.

“You’ll even see them sometimes on the vegetation. They’ll be wiggling their legs around like little antennae searching. Then what they do when they find that vertebrate host, they will latch on.” Typically, ticks must be attached for 36-48 hours or more before the disease can be transmitted.

Doctors say they should be removed carefully, with tweezers and by the head. “Do not, under any circumstances, burn the tick while it’s touching you, or put Vaseline or another chemical on the tick to get it to drop off,” says Dr. Erika Pallie of Morgantown. The infection can only be spread by ticks, and a person with Lyme disease is not contagious.

Lyme disease ticks spreading south and into Canada
And it isn’t only the intensity of tick transmission that’s being influenced by warming temperatures from climate change — but also where ticks choose to live, claims Nick Ogden, a zoonoses expert with the Public Health Agency of Canada. As regions of the southern U.S. experience overly hot temperatures and become inhospitable to ticks, other parts of North America — including Canada — may become newly suitable.

Dr. Richard S. Ostfeld, a disease ecologist who has studied the ticks and their habitats for 20 years, also cautions that warming from climate change is helping expand the ticks’ habitat.