Humans Have Paved the Way for a Global Lyme Disease Epidemic
Carved-up forests, biodiversity loss, and climate change may not have caused the tick-borne scourge, but they have enabled it
Excerpted from Lyme: The First Epidemic of Climate Change
On the day after Christmas in 2015, I took a walk with my 30-year-old son in an old cornfield that long ago morphed, with changing patterns of agriculture, into a gently tended meadow we know well. This nine-acre patch of earth, across the dead-end lane from our home in upstate New York, has a rare and wonderful feature that we have worked, with the cooperation of neighbors, to sustain: a mowed trail around its perimeter that allows access even when summer mustard, milkweed, and goldenrod are four feet high and the blackberry brambles profuse.
Photo by Jeb Bjerke
As we often do, we took with us that day a coterie of mismatched family dogs — a Shih tzu, Chihuahua, springer spaniel, and a beige rescue that we call a boxer.
The day was unusually balmy in the last week of a year that had gone down as the warmest in 135 years of weather history, followed only — but considerably — by the year before. The temperature had topped out at 55 degrees Fahrenheit that December 26th; it had reached into the mid-60s on Christmas and hit 72 in nearby Poughkeepsie the day before. For that time of year, daytime temperatures at or near freezing would have been far more typical here in the Hudson Valley, a hundred miles north of New York City. Instead, it had been so warm that forsythia buds had sprouted in one neighbor’s garden; crocuses peaked through in another’s.
When we came back from our short walk, we did what has become in New York State a routine practice from spring through fall, but not for winter. We checked the dogs for ticks. When we were done, we had picked twenty-one blacklegged ticks from the scruffs of our pups, each about the size of a small freckle, and all with one goal in mind: to latch onto a warm body and suck its blood.
When I moved to this rural county in upstate New York 30 years ago, such things did not happen. Ticks certainly did not show up in December, were indeed rare, and, if seen, were usually of the easier-to-spot dog tick variety, which infrequently carried Rocky Mountain spotted fever. They did not pack the potential arsenal of infection of the small, ubiquitous blacklegged ticks of today. Every year, the list of diseases found within this tick grows longer, including new bacterial, viral, and parasitic pathogens.
These infections have changed daily life in the county in which I live, and they have altered the course of many lives, particularly when they go unrecognized for weeks or months. Mention Lyme disease at a gathering here and nearly everyone has a story. The odd rash, fever, occasional palsy, meningitis, and joint pain of early stages. The sometimes-crippling arthritis, memory loss, depression, numbness, and fatigue of advanced disease.
Even the rare infection that can kill. In towns near me, Lyme carditis, in which the bacterium quickly cripples the heart, claimed a 17-year-old high school boy and a 38-year-old father of three within five months. A woman, who at 91 was an active gardener, died after being bitten by a tick and contracting another common tick-borne disease, babesiosis.
Blacklegged ticks have taken up residence in half of continental America’s counties, spreading west, north, and south from the Connecticut town for which Lyme disease was named in the late 1970s, like some unchecked algal bloom. These eight-legged arachnids have turned childhood from a time to explore nature to a time to fear it. My seven- year-old grandson has been warned since he could walk: Don’t brush up against the tall grasses at the edge of the trail. Don’t venture into the weeds. Tuck socks into pants. Sit still for repellent. Check yourself, and remind Mommy to also.
Then, pray we see the tick, and pity the parent who doesn’t know to look. Guidance counselors and teachers have told me of children, the most frequently infected, missing months, sometimes years, of school because the tick went unseen or the symptoms were misconstrued. But happenstance is not the only reason that cases are missed or treatment delayed, I have learned. Many patients have suffered needlessly, in the United States, Canada, England, France, Germany, and many other countries, because of how Lyme disease has been framed in American medical journals and treatment guidelines. This is an illness that has been minimized, underestimated, and politicized to the point that doctors fear treating it aggressively with a cheap, common drug: antibiotics.
I began to write about Lyme disease as an investigative reporter for a Dutchess County, New York, newspaper in 2012. I intended to write one or two stories about a prevalent local disease, focusing on its origins, growth, and management by health officials. But Lyme disease proved to be a story far beyond the parameters I’d envisioned. Over a period of four years, I studied the policies, paper trail, and scientific literature. I tested the postulates of patients and their advocates. Many of their assertions, I concluded, were true.
Decades-old testing protocols failed to diagnose many people with the disease. The risk of overtesting — and falsely diagnosing people with Lyme disease — was exaggerated at the expense of cases missed and symptoms dismissed. Official figures did not reflect the epidemic’s scope and were soon revised tenfold. Human trials concluded that short-term antibiotics eradicated the bug, while animal and test-tube studies showed they didn’t.
And then there was the politics of Lyme disease. Doctors who prescribed repeated courses of antibiotics — standard in other diseases — faced professional disciplinary charges, huge legal fees, and sometimes suspension or loss of their licenses. Research was discredited, ignored, or relegated to second-tier journals when it challenged prevailing dogma. Scientists who were invested in a benign view of Lyme disease used access to elite journals to uphold the status quo. And little money was available for treatment trials because the medical system purported to have the answers to Lyme disease care.
And yet, some 10 to 20 percent of people infected annually with Lyme disease, estimated at 380,000 Americans in 2015, have symptoms that linger months and sometimes years after treatment. The United States Centers for Disease Control and Prevention (CDC) calls the condition Post-Treatment Lyme Disease Syndrome, and it affects multitudes of people as disease-toting ticks move around the world. Lyme disease is rife in most every country in Western Europe. It is in Russia, China, former Soviet satellite states, and though officially unrecognized, in Australia too. In one small study, half the ticks in two parks in New York City harbored the Lyme disease pathogen. In a Chicago park, Ixodes ticks, some laden with the Lyme pathogen, outnumbered every other tick carried by migrating birds in 2010; five years earlier, there were none. In a northwestern suburb of Beijing, one in twenty residents tested positive in a Chinese study that said, quite remarkably, “Underdiagnosis of early Lyme disease and physical damage at advanced stage are huge problem [sic] in this area.”
But infected ticks haven’t just moved around. They have added layers of woe. Forty-five percent of ticks in the French Ardennes, for example, carry more than one disease; some have five. A tick-borne malaria-like illness, babesiosis, unheard of not so long ago, became a nationally reportable disease in 2011 after cases skyrocketed in some American states — and it slipped into the US blood supply, infecting premature babies and killing at least eight people. Another rapidly emerging pathogen, Borrelia miyamotoi, prevalent in the San Francisco Bay area, has upped the ante on Lyme. Tick babies, hatching by the thousands, can inherit the bug directly from mom rather than get it with its first animal blood meal. Add to this Powassan virus, which is also passed to baby ticks, transmitted within fifteen minutes of a bite, and is fatal 10 percent of the time, and anaplasmosis, a bacterial infection that is particularly dangerous for the elderly. Now consider how a tick infected with two or three of these organisms, for which a doctor may not know to look, and for which testing is not routine, can wreak havoc in a human body.
This spreading toll of tick-borne disease is not a random act of nature. By virtue of the developed world’s lifestyle and influence — the cars, the suburban tracts and carved-up forests, the diminished biodiversity, the emissions and airplanes — we have paved the way for the first global epidemic abetted by climate change. Warming may not have caused this scourge, but it most certainly is enabling it.
The pathogen that causes Lyme disease, Borrelia burgdorferi, has existed in the environment for millennia, just as blacklegged ticks have long been transported on the wings of birds to new and far-flung climes. What is different is that they now survive there. We have revived and empowered a sleeping giant, the Borrelia bug, by helping to create conditions favorable to the ticks that deliver it.
Climate change alone hasn’t done this — ticks thrive amid the mice and deer so prevalent in an attenuated, postindustrial era — but its influence in supporting ticks, the vector of human transmission, is key. Ticks have climbed latitudes like ladders; they have moved up mountains. Driven by warmer winters and earlier springs, they are predicted to move well north into Canada in coming years, just as they migrated up the Atlantic seaboard and north into Scandinavia at the close of the twentieth century.
Lyme disease, of course, is not the only epidemic to blossom in our changing world. Illnesses carried by mosquitoes — Zika, West Nile, Chikungunya, dengue fever, malaria — are proliferating and are predicted to worsen as the globe warms. The diseases they carry today annually cause millions of illnesses in tropical countries — and in the case of malaria, nearly a half-million deaths.
When these illnesses arrive on US shores, they capture the public imagination and lead the nightly news in a way that Lyme disease never has. Yet the Lyme toll in the United States and many developed countries is far higher — perhaps four or five million Americans infected to date — than West Nile, Zika, and all other mosquito-borne illnesses combined. And like West Nile, Lyme sometimes kills, although the numbers are largely unknown. Late-stage Lyme disease has even led to suicide, an outgrowth both of the illness and society’s regard for it.
For official purposes, Lyme disease is not called an epidemic. It is an “endemic,” a term with far less urgency, reserved for an illness that comes to stay. It emerges. It takes root. And it does not leave. It is a slow burn, this scourge, established, entrenched, and for many, inescapable. But its second-class status also stems from how Lyme disease has been managed and shaped. Treatment guidelines issued by the Infectious Diseases Society of America (IDSA) in 2006 diminish the lingering symptoms of Lyme disease sufferers, calling them the “aches and pains of daily living.” This, while studies from Columbia University, Johns Hopkins, and elsewhere have measured significant neurological, cognitive, and physical impairments in treated patients. One study equated the quality of life of those with longstanding Lyme disease to people with congestive heart failure. Others have linked the disease to mental illness and showed brains deprived of blood flow.
Borrelia burgdorferi is a clever, adaptable bug. It has a hugely complex genetic profile, with more independently replicating structures, called plasmids, than any other bacterium. It doesn’t need iron, unlike most other bacteria, removing one option for our immune systems to starve it into submission. It grows slowly, confounding drugs that work on rapidly dividing cells. It hides in places that diagnostic tests do not reach. This tiny spiral-shaped organism is actually a boon to ticks. Those infected are more likely to find a blood meal, and ominously, may even cope better in dryer, hotter conditions, than those that do not carry the Lyme pathogen.
In 2014, a report by the Intergovernmental Panel on Climate Change, a multinational effort, said the period from 1983 to 2012 was likely the warmest 30 years in the Northern Hemisphere of the previous 1,400 years. The report, relying on multiple, independent temperature and climate indicators around the globe, called this “robust multi-decadal warming.” Tellingly, the US government monitors Lyme disease as a key indicator of the effect and pace of climate change. Like millions of other people, I see this change in my everyday life. It means that on a short walk in late December, I found twenty-one ticks on four panting, happy dogs that like nothing better than a romp through our shared preserve.
When I look at that lovely field, I see something else. I see a beautiful, inviting menace, a dark and dangerous wood. I see the first epidemic in the era of climate change, long in the making, global, and here to stay. Call it, if you will, the first pandemic. There are things we can do to protect ourselves, to control the bug, to limit its spread. You will read about that in this book. But you will read also about the missed opportunities, the misconceptions, and the human contribution to an epidemic that, for now at least, is beyond our ability to stop.
This essay was excerpted from Lyme: The First Epidemic of Climate Change, Island Press, 2018.