Nature is usually my best friend, but occasionally it has played my nemesis. While backpacking in Africa, for example, I had a heart-stopping stare-down with an angry lion. In Alaska I was charged by a protective mother moose. In Yellowstone I anxiously jingled bear bells while working in grizzly habitat. I was even struck by lightning while hiking in Massachusetts, of all places. The last force of nature I ever expected to bring me down was a tick the size of a sesame seed, but that's exactly what happened.
It was the summer of 2008. My husband, two young children and I had temporarily moved from our McKinleyville home into a cabin in the Colorado Rockies. During the days my husband taught college students while I tried to write and take care of our kids. "Tried" is the operative word. I couldn't seem to do anything but sit and sleep.
"It's the altitude," I kept telling my family. "I haven't adjusted yet." But secretly I wondered. I'd lived in the Rockies before, and I'd always acclimated quickly to the thin air. Weeks went by and instead of taking my kids backpacking or even hiking I opted for lazy days by the river. No complaints there, except that I felt sluggish, disappointed, and definitely not myself.
Soon I started having bouts of extreme fatigue. I'd crash on the couch or bed and sleep for an hour before waking up, not exactly rested but at least able to stand again.
My husband insisted I see a doctor, but since we were near the end of our stay I opted to wait until we returned home. On the long drive back to Humboldt County, a knuckle on my left hand began to swell and throb and my right knee began to ache. By then I knew something was wrong with my body.
Let's backtrack a few months. In March of that same year my family and I had gone to an animal shelter near Eureka where we found a three-month-old fluffy black pup. During our first days with "Cody" we discovered several ticks on him, either attached or ambling across his coat. Having picked ticks off many dogs I thought nothing of it. I wasn't even alarmed when a few days later I found a tick imbedded in my upper thigh. I yanked it out, but the head stayed embedded in my flesh, and the area around it stayed inflamed. So I went to see my doctor. She removed the head and, mentioning the possibility of Lyme disease, put me on a 10-day course of antibiotics. I knew very little about Lyme, but I took the medicine and put the tick bite out of my mind.
Half a year later I was back in my doctor's office explaining my symptoms of joint pain and fatigue. After blood work and laboratory tests, her diagnosis was confirmed: Despite the short course of antibiotics following the tick bite, Lyme disease had survived and multiplied inside my body.
What Exactly Is Lyme?
Lyme disease is an infection caused by a microscopic parasite, a type of bacteria called Borrelia burgdorferi. B. burgdorferi (for short) is transmitted to humans by the bite of infected ticks.
Though rarely fatal, Lyme can cause symptoms as debilitating as those experienced by people with chronic heart disease and multiple sclerosis. Many Lyme patients experience joint and muscle pain and extreme fatigue, as I did. Others have it worse. If the bacteria get into your central nervous system you could face short-term memory loss, speech problems and anxiety attacks, among other symptoms. Doctors refer to Lyme as "The Great Imitator" because its symptoms can mimic a broad spectrum of illnesses.
If Lyme reveals itself early with a telltale bull's-eye skin rash, a month-long course of antibiotics is often enough to stop the infection. Unfortunately, many sufferers never develop bull's-eye rashes, or are prescribed an inadequate duration of antibiotics. In these cases, the symptoms progress slowly, making the disease harder to diagnose and treat.
"Lyme is the most complex bacterium I've ever heard of," says Dr. Beverly Copeland, a family medical doctor in McKinleyville. "Some bacteriologists say it's the most amazing, stealthy, clever bacteria that they've seen."
Dr. Ray Stricker, considered by many to be the West Coast's foremost expert on Lyme disease, agrees. Though he cautions against anthropomorphizing a bacterium, he says B. burgdorferi is "very ‘smart' in the sense that it knows which cells to invade to get a free ride into the brain."
In addition to what Dr. Stricker calls "the Trojan horse effect on the brain," Lyme hides, masquerades and morphs in ways that help it take hold in many areas of the human body. It hides by leaving the bloodstream and ducking into tissues less accessible to the immune system and antibiotics. It masquerades by changing its surface proteins to evade existing antibodies. Lastly, it morphs from its elongated spiral shape into a dormant cyst form, which the immune system doesn't recognize and antibiotics can't penetrate.
The bacterium B. burgdorferi is the true bad dude of Lyme disease, but it wouldn't get anywhere without its two powerful accomplices: the vector and the host. Though neither knowingly conspires with the bacterium to spread the disease, each plays an important role in doing just that.
Vectors of Lyme disease are tiny ticks, some no bigger than a pin head. B. burgdorferi live in the mid-guts of some ticks and are transferred to humans and other animals when the ticks bite, taking what scientists call a "blood-meal."
The most common vectors of Lyme disease belong to the genus Ixodes. Commonly called deer ticks or black-legged ticks, different species of Ixodes occur regionally throughout the world. Deer ticks can carry different strains of the Lyme bacterium, and each strain can cause different symptoms. Strains found in Europe, for example, cause more skin lesions but less joint pain than strains found in the United States, Dr. Stricker says. Meanwhile, strains on the East Coast tend to cause more heart issues than those on the West Coast. Among adult deer ticks, only females transmit Lyme. But pre-adult ticks, or "nymphs," can be even more troublesome. No bigger than poppy seeds and typically infected with Lyme in greater proportion than adult females, nymphs are as stealthy as the bacteria they harbor.
B. burgdorferi's second accomplice is its host. Without hosts, ticks couldn't survive. Animals, including mammals, birds and reptiles, play host to Lyme-vectoring ticks, yet not always to the bacterium itself.
Some wildlife hosts are more instrumental than others in maintaining the Lyme bacterium in a particular region. Hosts that are particularly important are those that are fed upon by infected ticks -- usually those in the larval and nymph stages -- frequently enough to sustain the disease within their populations. Typically, these hosts are fast-breeding small mammals.
Dr. Rick Brown, a disease ecologist studying Lyme at Humboldt State University, says, "The most important hosts to the bacteria are white-footed mice back east and western gray squirrels on the West Coast." He is quick to point out, though, that usually two or more species serve as important bacterial hosts.
Large mammals, like deer, are not important hosts to the bacteria, but they are to the vectors -- ticks. By providing blood-meals and breeding grounds for a lot of ticks, large mammals keep tick numbers high.
Tick Habits and Habitats
Deer ticks don't jump or leap onto their hosts; they crawl and "quest" by positioning themselves on leaves or blades of grass, then raising their clawed forelegs. Aided by carbon dioxide sensors on their legs, they anticipate approaching animals and grab onto their furry coats as they pass by. Or, in the case of people, they grab onto pant legs or shirt tails.
Deer ticks live in grassy, shrubby, and wooded areas that provide food and cover for their small mammal hosts. In forests they are commonly found in leaf litter and on logs. Deer ticks require high humidity, which explains why they are often found in tall grass meadows but not in closely cropped lawns.
Lyme disease has been diagnosed in every state in the U.S., though it's not certain that all cases originated in the states where they were diagnosed. What is certain is that there are three hot spots of Lyme disease in the nation: the Northeast and Mid-Atlantic States, the Upper Midwest, and here in Northern California. These areas have all the necessary environmental criteria to support high numbers of Ixodes ticks: abundant small mammals to host B. burgdorferi; burgeoning deer herds; and fields, forests and wooded backyards where people come in contact with ticks.
Obviously, the best way to avoid contracting Lyme disease is to avoid getting bitten by a tick. When hiking, camping or working in the backyard you can protect yourself by tucking in your shirt and pant legs, spraying clothes with permethrin and wearing tick repellant on your skin. If you find a tick on you, it's important to remove it promptly but also properly. The last thing you want to do is squeeze Lyme bacteria into the bite. Once the tick is removed, save it in a plastic bag and take it to your local public health office, where it can be tested for Lyme disease.
A Growing Epidemic
The Center for Disease Control has reported a steady rise in new cases, surpassing 30,000 in 2009. Dr. Stricker says "the actual number could be, at the very least, 10 times what the CDC reports." (The CDC itself acknowledges that cases are underreported by six- to 12-fold.)
Unfortunately there's a schism in the American medical community over the diagnosis and treatment guidelines for Lyme disease -- particularly regarding lingering symptoms like fatigue, sleep disturbance and cognitive difficulties. Nonprofit agencies like the California Lyme Disease Association (CALDA) and the International Lyme and Associated Diseases Society (ILADS) argue that these lingering symptoms can be caused by the persistent presence of B. burgdorferi, while other agencies, including the Infectious Disease Society of America (IDSA), have been hesitant to say definitively that the bacterium is to blame for these chronic symptoms.
Both groups agree that early treatment is best, but that requires early detection, which doesn't always occur. Doctors in the IDSA believe that Lyme disease can be treated with a two- to four-week course of antibiotics, and if symptoms persist the IDSA contends that they likely indicate an autoimmune problem, a "post-Lyme syndrome" that will not respond to antibiotics.
ILADS doctors, on the other hand, believe that continued symptoms are likely due to an ongoing Lyme infection, what physicians sometimes call "chronic Lyme." They maintain that these symptoms should be treated with antibiotics and a healthy lifestyle until they are resolved. Some ILADS physicians also treat or control chronic Lyme infections with herbal remedies, particularly in cases where patients can't tolerate antibiotics.
To further complicate matters, ticks often carry other diseases, including Bartonella, Babesia and Ehrlichia. Doctors are learning that Lyme patients often have one or more of these "co-infections." While they are easier to treat than Lyme, they often complicate and delay Lyme treatment until they are cleared up.
A recent survey by CALDA of 3,600 Lyme patients found that, on average, respondents had seen seven doctors before proper diagnosis. Dr. Stricker says no two cases are exactly alike. "About 70 percent of my patients get all better, but it can take months to years of treatment to get to that point," he says. "It's very unpredictable, and everyone is different."
When I first met Dr. Stricker he said, "I always tell people that I have the healthiest patients in the world because they are the ones who are out hiking and camping and doing all the things they're supposed to do; that's why they get bitten by ticks!" At the time he said this I couldn't hike or even ride my bike up a short hill. In fact, I could barely work because my short-term memory was shot.
I remember thinking, "Let me be one of those healthy people again." More than a year later, after intense antibiotics and a very healthy diet, I have my life back. I'm not completely better yet. But I can exercise, and I can work. And this past summer I was able to go backpacking in the mountains with my kids.
A version of this story first appeared in the February 2011 issue of Oddysea: Adventures in Science, a national magazine for young teens. Author Carol Ann Moorhead has a Master's degree in wildlife biology and has written two natural history books for middle graders. She lives in McKinleyville.
Local resources are available through the Humboldt Lyme Awareness Group, a local nonprofit formed in 2009. They can be reached at (707) 825-7835, or visit their website, www.humboldtlymedisease.org.
SIDEBAR #1: Lizard Luck
Despite the state's abundance of ticks, Lyme disease occurs less frequently in California than in the eastern United States. Why? At least in part, it's "lizard luck."
For more than a decade, scientists at the University of California at Berkeley have reported on Lyme-killing proteins in the blood of certain lizards common to the state. The blood of western fence lizards (Sceloporus occidentalis) and southern alligator lizards (Elgaria multicarinata), when fed on by a Lyme-infected tick, kills the bacteria inside the ticks' guts.
This may explain why 30 percent to 60 percent of adult female deer ticks in the eastern United States (Ixodes scapularis) carry Lyme disease compared to only 1 percent to 6 percent of adult females in California (Ixodes pacificus).
SIDEBAR #2: What's with the name?
In 1973, Judith Mensch and Polly Murray, two concerned New England mothers, began to alert doctors about the growing number of children in their neighborhoods who were developing unusual symptoms including rashes, aching joints and neurological problems like partial facial paralysis. Originally diagnosed as a form of juvenile rheumatoid arthritis, the suite of symptoms was given the name "Lyme Arthritis" after Old Lyme, Connecticut, the town where Mensch and Murray became aware of the illness.
The illness was renamed "Lyme Disease" some time after 1982 when scientist Dr. Willy Burgdorferi isolated the bacterial pathogen that causes the disease from in the mid-gut of a deer tick. It was a new species of Borellia bacteria, later given the name Borrelia burgdorferi, after the scientist.
SIDEBAR #3: Tick Talk
How not to get bitten
Avoid the path less traveled: Walk in the middle of trails and don't sit or lean on logs or trees
Wear light-colored clothes and long sleeves so you can easily see ticks
Sacrifice coolness: Tuck your shirt into your pants and pant legs into your socks
Put insect repellant on your clothes and skin
After you get back to civilization, immediately do a thorough check for those little suckers, then keep checking your bedding for a few days afterward
If you are bitten
There's no shortage of folk remedies, from counter-clockwise twisting to burning the tick's butt with a smoldering match head. But the best technique is simply gripping the tick as close to the skin as possible with fine-point tweezers, then pulling it straight out with steady, even pressure.
Once it's out, put it in a small plastic bag with a leaf or blade of grass, then label it with your name, the date, the site of bite and how long tick was attached. Take it to the health department or a veterinarian for identification
Wash your hands and disinfect the tweezers and the bite site
Source: The California Lyme Disease Association