Kerry Clark thinks he’s developed a better test to diagnose the illness.
By Jeremy Cox Story updated at 5:16 PM on Tuesday, May. 19, 2009
“Tick-borne Disease Research Area - Please Do Not Enter,” the sign says on the front door of Kerry Clark’s University of North Florida office.
If that’s not enough of a deterrence, there are always the photographs of Florida’s three most common tick species blown up to larger-than-life proportions.
But it’s worth poking inside the seemingly menacing door if only to meet Clark and listen to his story.
“It’s like a great mystery,” Clark said.
The villain of his story is Lyme disease, a poorly understood illness that’s spread by tick bites to tens of thousands of Americans each year. After a decade of paltry funding and suffering countless tick bites himself, the 40-year-old epidemiology professor has reached a scientific breakthrough that stands to revolutionize the way doctors diagnose and treat Lyme.
In addition, his toil has revealed an unsettling message for the people of Florida and other parts of the South: Lyme-carrying ticks are spreading the illness here at vastly higher rates than what public health statistics and experts have suggested.
Disease’s spread
Lyme disease follows a perplexing arc that begins with a bull’s eye-shaped rash and vague, flu-like symptoms. Without treatment, Lyme digs in deep, progressing to potentially disabling effects, like severe arthritis, fatigue, numbness in the hands or feet and neurological problems.
The vast majority of the more than 265,000 cases of Lyme disease reported since 1993 have come from the Northeast and upper Midwest.
That’s a conservative number. Scientists think there are seven to 12 cases for each one that is reported. And even that dire-sounding estimate may be too low. Only about 40 percent of positive cases are getting detected by traditional diagnostic tools, which test the body’s reaction to the Lyme bacteria, Clark said.
Clark thinks that his test, which involves looking for Lyme’s DNA in the victim’s blood, is a more accurate way of detecting the disease.
For many, an inaccurate test is a life-changer.
Caught early, the Lyme bacteria usually can be wiped out with antibiotics. But many cases go undetected for years because people, though sick, often don’t know they’ve been bitten by a tick or don’t develop the tell-tale rash.
Not safe in the South
People like Dane Boggs. For a decade, Boggs, a home builder, felt tired all the time and his joints hurt. But his symptoms were mild, so he figured they were merely the side effects of getting older.
Things got worse, though, after he was bitten by a tick on a job site in Atlantic Beach five years ago. He now thinks that his previous decade of troubles were caused by a tick bite that went unnoticed.
The double whammy of bites nearly crippled him, he said.
“My immune system was kind of fighting it off for 10 years, but when I got bit [the second time], that’s when I got super-sick,” Boggs said. “I just wanted to go to bed all the time. It was like an 18-wheeler ran over my body.”
The Ponte Vedra Beach man retired early to devote all his time to fighting the illness. He took powerful antibiotics for two years with little improvement. So he turned to an alternative therapy that uses electrical frequencies to zap microscopic invaders like Lyme disease.
Today, the 55-year-old is healthy, though he cautions his results from the alternative treatment probably aren’t the norm. After his battle, Boggs co-founded a research and support organization called the Northeast Florida Lyme Association.
“Nobody even believes Lyme disease is in Florida. But it does exist, and a lot of people are sick,” said Boggs, who has found a sympathetic ear and a NEFLA board member in Kerry Clark.
Finding new strains
Clark’s research has revealed that Lyme disease is much more common in Florida than previously known.
State disease-surveillance efforts confirmed 88 cases last year, 11 of which are believed to have originated in the state. But Clark has found the Lyme bacteria in virtually every corner of the state, including hordes on the First Coast.
The perception that the South doesn’t have a Lyme problem has biological roots.
In the Northeast, mice are the primary reservoir of the Lyme bacteria, known among scientists as Borrelia burgdorferi sensu lato. But in the South, lizards are ticks’ prime target. And since studies in California showed that reptiles were poor reservoirs, many scientists concluded that the South was relatively safe.
But Clark’s studies of lizards in South Carolina and Florida revealed that 54 percent were positive for Lyme disease. That research petered out because of a lack of funding - a frequent complaint of Clark’s - but it led him to perfect what he believes to be the most sensitive testing method yet for the disease.
Lyme disease is hard to detect in lizards because their blood is highly concentrated with their own DNA, overwhelming the genetic tidbits of any other organisms that might be in their systems. By applying the same amplifying methods he developed for lizard samples, Clark started getting positive readings in human samples that had previously tested negative.
Clark put his theory to the test on 150 blood and skin samples collected from patients suspected of having Lyme disease.
Forty-four percent came back positive, including 20 of the 49 samples from Florida.
What’s more, for the first time anywhere in the United States, he found two additional strains of Lyme disease in humans: Borrelia andersonii and another that has not yet been named.
At least five strains of Lyme are known to infect animals and ticks, but researchers had never seen more than one in humans, Clark said. Most diagnostic tests were only developed to detect one Lyme strain. So if more are infecting humans, Clark thinks, that may explain why they have such a high error rate.
A paper detailing his findings is in review with the Journal of Clinical Microbiology.
Andrea Varela-Stokes, a parasitologist at Mississippi State University, said she is intrigued by Clark’s research. She called the understanding of Lyme in the South a “tricky situation” because scientists have been unable to grow the Lyme bacteria in laboratory cultures from sick patients.
Although Clark ran into the same problem, he thinks he’s had a breakthrough.
“I think the paper is a really big deal,” he said. “One of two things is going to happen: They’re going to say, ‘This is that weirdo who did all that lizard stuff.’ Or they’re going to say, ‘Why didn’t we do that?’ ”
jeremy.cox@jacksonville.com, (904) 359-4083
http://www.jacksonville.com/lifestyles/health_and_fitness/2009-05-19/story/unf_professor_works_to_unlock_lyme_diseases_mysteries
People going camping or walking on the North York Moors are being urged to take precautions to prevent them being bitten by ticks.