Eight-Legged Terrors By the Bay
By Henry S. Parker
This is not an article about the octopus. Those eight-legged sea creatures don’t inhabit Chesapeake Bay, and they’re far less scary than the subject creature here.
The Bay Area offers some of the finest walks on the East Coast. The region abounds with charming trails that meander across bucolic fields, through shady woods and along scenic shorelines from Havre de Grace to Hampton Roads. But these days you ramble at a risk. A diminutive demon lies in wait.
Must be an insect, you’re thinking. But doesn’t an insect have six legs? Correct, but this scary creature is a tick, and a tick is not an insect. It’s an arachnid, related to a spider, and like a spider, it has eight legs. And it can instill fear.
Most ticks are tiny. While some may be a half-inch long when filled with blood, many are pinhead-sized. More than 800 species populate the world, but only a few reside in the U.S. Ticks are widely distributed, but do best in warm, humid environments. They’re survivors and have been around for some 300 million years. They’re abundant; in some parts of the northeastern U.S. their numbers approach 1,000 per acre. And they can be dangerous.
The danger comes from disease. Ticks harbor bacteria, viruses and parasites. Bites from ticks can transmit a rogue’s gallery of horrendous maladies. A few examples: Tularemia, a life-threatening illness so debilitating that the responsible bacterium is considered a potential bioterrorism agent; Rocky Mountain spotted fever, which can be fatal if not promptly diagnosed and treated; Babesiosis, a parasitic disease that causes anemia but probably won’t kill you; Crimean-Congo hemorrhagic fever which has an even chance of doing you in even as you bleed out from your body orifices (fortunately it’s not in the U.S.). And then there’s Lyme disease.
First discovered only a few decades ago in coastal Connecticut, Lyme disease now rages across the country, sickening perhaps 300,000 Americans every year. The responsible bacterial pathogen resides in the abundant blacklegged or deer tick. The Bay Area is a prime habitat for deer ticks and a hot zone for Lyme disease.
The path to infection is distressingly easy. A tick feeds on blood. It can’t travel far on its own, and hitchhikes to expand its range. Perched on a bit of vegetation, it lies in wait, forelegs outstretched. When a suitable host passes by—any mammal will do—it climbs aboard, seeks a patch of bare skin, scissors a tiny opening, secretes an anti-coagulating chemical, inserts a feeding appendage and engorges itself with blood. If the tick is carrying Lyme disease bacteria, the pathogen is transmitted to the host.
A well-nourished tick can produce thousands of eggs at once. The eggs develop into larvae, then nymphs, and finally adults. At every stage, on every host, the germs get passed along. If a bitten human is lucky, the bite site will show a bulls-eye pattern, and the individual can be tested for Lyme disease and seek treatment, including antibiotics. Less fortunate victims may not detect the bite, but experience a rash and flu-like illness that can trigger a visit to the doctor. The truly unlucky don’t realize they’ve been bitten, don’t experience (or ignore) alarming symptoms and can go years before the disease is evident. By then it may be too late. Chronic neurological symptoms, arthritis-like pain, cognitive impairment and even death can result.
Preventive measures are essential. It’s important to wear long-sleeved shirts, tuck pant cuffs into socks, don a hat and cover all exposed skin. But in the humid, 90-degree mid-Atlantic Summer, many outdoor enthusiasts might be forgiven for relaxing such dress standards. You could lather yourself with insecticide, or wear a flea and tick collar (a fashion statement in some locales). You should thoroughly inspect yourself—and your (hopefully) significant other—after a walk in the woods. A vigorous shower isn’t a bad idea. But these measures aren’t foolproof. Ticks can hitch a ride on clothing and drop off in your car or house. They can burrow into nether regions where a body search won’t turn them up. And they can nestle into the fur of a pet.
So what to do? You could stick to the water. No aquatic tick species have yet evolved. You could move to Alaska. But that would involve a trade-off with larger threats like grizzly bears, wolves and mosquitoes the size of Piper Cubs. Besides, ticks have even made their way up there, too. Or you could play it safe, remain in the house, curl up in front of the TV, and tune in the National Geographic Channel—or the latest episode of Naked and Afraid.
But who wants to stay inside? With appropriate precautions and common sense, your risk of tick-borne disease is greatly diminished. So dress for the occasion, venture out and enjoy the great outdoors.
For further information about Lyme disease and its prevention, see: http://phpa.dhmh.maryland.gov/OIDEOR/CZVBD/SitePages/lyme-disease.aspx
Henry is an adjunct associate professor at Georgetown University. He previously directed research programs at the U.S. Department of Agriculture and taught marine sciences at the University of Massachusetts Dartmouth. He can be reached at firstname.lastname@example.org