The debilitating tick-borne disease is well-documented north of the Mason-Dixon line, but does it exist beyond that?
Kerry Clark never wanted to show that Lyme disease exists in the Southern United States by catching it himself.
Clark is a medical entomologist at the University of North Florida in Jacksonville. A wiry man with graying brown hair, he is most at home in a kayak on the ponds behind the wooded Jacksonville campus. He jogs and lifts weights, when he is well enough to do so.
Clark has spent years all over the South crawling through underbrush and kicking up leaf litter to collect ticks that transmit infections. Despite innumerable tick bites, Clark never had a medical problem until the day he dragged for ticks in the town of Fayetteville, a suburb south of Atlanta.
Clark was giving a talk on Lyme disease at a gathering of the Dougherty County Medical Society in Albany, Ga., where he met Fayetteville resident Liz Schmitz, president of the Georgia Lyme Disease Association. When he heard how many people from Schmitz’s town had been sickened after tick bites, he agreed to come up and investigate.
As Clark dragged for ticks with a white flannel cloth on a pole, hungry, aggressive lone star females with their distinctive white spots seemed to burst out. In less than an hour, he had collected hundreds of adults and younger nymphs. He remembers one practically leaping from the cloth onto his finger. And that, Clark guesses, is when a lone star tick nestled in his hair. When Clark found it several days later, it had already deposited its bacterial load into his body.
Since that day almost three years ago, Clark has been suffering from what he describes as intermittent pounding headaches, fatigue, odd twitches and “fuzziness.” He reports that weeks-long courses of antibiotics make him feel better, but when he goes off the drugs, the symptoms return.
Clark is not alone. Other people from suburban communities around Georgia — and many other areas of the Southeast — report getting sick from what seems like tick-borne illness, too.
A man in his 50s from Fayette County who prefers not to use his name developed severe neurological symptoms after a tick bite. Initially his right foot dragged, and he couldn’t use his right arm at all. He was diagnosed with the lethal neurodegenerative disease ALS (for amyotrophic lateral sclerosis, also known as Lou Gehrig’s disease.) ALS gradually kills off motor neurons, causing progressive paralysis. It initially leaves patients weakened, then in a wheelchair, and then, within a few years, unable to eat or breathe.
The last specialist sent him home to die. But after talking with Schmitz, the man sent Clark samples of his blood. Using polymerase chain reaction (PCR) testing to analyze fragments of foreign DNA in the man’s blood, Clark found evidence of Borrelia burgdorferi, the pathogen that causes Lyme disease. Now on antibiotics, the Fayette County man says he feels better than he has in years, and the rapid downward trajectory common to almost all ALS patients seems to have stalled.
Clark also tested his own blood, where he found traces of B. burgdorferi along with another distinct genospecies (a bacterial species separated by divergence of genes), Borrelia andersonii, usually found in rabbits.
There is just one problem with this story: Many Lyme researchers, including some from the National Institutes of Health (NIH) and the Centers for Disease Control and Prevention (CDC), won’t believe a word of it. There is little or no true Lyme disease anywhere in the South, say these experts.
They cite plenty of evidence: In the Northeast, where Lyme is endemic, the disease is spread by nymphs (the tick’s juvenile form) of Ixodes scapularis, commonly known as blacklegged ticks. Blacklegged nymphs rarely bite humans down South, though researchers don’t agree as to why not. Adult blacklegged ticks do bite people, but because of their large size, they’re often noticed and picked off before they spread disease.
So if there is Lyme — or Lyme-like illness — in the South, what could be spreading it? The aggressive lone star tick, Amblyomma americanum, which frequently bites people as well as other animals, is a prime suspect. In the early 1990s, researchers realized its bite could cause a roundish, gradually spreading mottled red rash that was a virtual ringer for the erythema migrans (EM) rash, the classic signature of Lyme disease in the Northeast.
But since few Lyme experts believe that the lone star can harbor and transmit Lyme Borrelia, the rash the tick leaves upon biting is never attributed to Lyme disease. Instead, in the South, the illness is called STARI, for Southern Tick-Associated Rash Illness. According to microbiologist Barbara Johnson, one of the top Lyme disease experts at the CDC’s Division of Vector-Borne Diseases in Fort Collins, Colo., STARI is relatively benign, presenting only with the rash and flulike symptoms of early Lyme. Its cause remains unknown.
And this is where the CDC and researchers like Clark and his colleagues part ways: Clark recognizes that Lyme disease transmitted by blacklegged ticks is relatively infrequent in the South. But he believes that lone star ticks can transmit a similar spiral-shaped bacterium or spirochete to the one that causes Lyme disease.
Other scientists disagree. While strains of Borrelia burgdorferi can be found in the South, says Jean Tsao, a Lyme researcher from Michigan State University, there is no bridge between the natural and the human world. Instead, the disease cycles are “cryptic,” meaning the spirochetes cycle quietly among ticks and animal hosts but have virtually no effect on human health.
Getting to the truth here is critical — especially to the thousands of patients who believe they suffer from some form of Lyme disease acquired in the South. The confusion starts with the numbers. No one has any clear idea how many STARI cases exist because, unlike Lyme in the North, they are not reportable to state departments of health.
Gary Wormser, an infectious diseases physician at New York Medical College and a recognized Lyme researcher, says STARI is “pretty widespread in the Southeast and south central part of the country.” Yet, Adriana Marques, chief of clinical infectious diseases at NIH, launched a study of STARI in 2002, and enrolled only three suspected patients over 10 years.
But Marcia Herman-Giddens, scientific adviser for the Tick-Borne Infections Council of North Carolina, a research and advocacy organization, says she can’t believe anyone actively looking for STARI patients would come up with just three of them in a decade. Patients with Lyme or Lyme-like illness in the South likely number in the thousands, she says.
The dispute leaves Southern patients who insist they have Lyme disease — or something much like it — angry and adrift. Because few doctors recognize their illness, they say, they are treated too late or not at all, and are allowed to slide into chronic illness as debilitating as untreated Lyme disease in the North.