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Sunday, July 21, 2002

By Joe Smydo, Post-Gazette Staff Writer

The thrill of the hunt is vanishing from a beagle club's training grounds in West Deer, Allegheny County.

That's because the rabbits, infested with blood-sucking ticks, are too weak to run quickly or far. Some have dropped dead.

Have members of Central Beagle Club Inc. put themselves at risk by venturing into the woods with their dogs?

Richard Dryden, Washington and Jefferson College biology professor and emerging authority on tick-borne disease, aims to find out.

Rabbit ticks from the club's 110-acre preserve will be tested in Dryden's laboratory for Lyme disease and other human diseases. A $3,000 grant from Allegheny County Health Department will fund the work, part of Dryden's career shift about four years ago.

After 25 years at W&J, Dryden decided to take his first sabbatical in fall 1998. An article about tick-borne illness piqued his interest, and he spent about two months at the Centers for Disease Control and Prevention in Atlanta, learning how to extract the critters' DNA and test it for bacteria that sicken humans.

Upon returning to W&J, Dryden obtained testing equipment and enlisted promising students in what has become groundbreaking research.

"This is work that will be referenced," said Joshua Courtney, a 2001 graduate and aspiring physician who assisted Dryden with tick research.

Of the 263 deer ticks Dryden's team collected at Presque Isle State Park in Erie County the past two years, 162 -- nearly 62 percent -- tested positive for Lyme disease. That, Dryden said, may be the highest concentration of the disease reported in any study nationwide.

Each year, about 16,000 Americans are infected with Lyme disease, which causes fatigue, headache, muscle aches and joint pain. If untreated, the disease can lead to inflammation of the brain and heart problems, according to the CDC.

The W&J researchers also were the first to find ticks at the state park infected with a more obscure disease, human granulocytic ehrlichiosis, or HGE, which causes flu-like symptoms and sometimes is fatal.

"That's an important first," said Dryden, who has a doctorate from North Carolina State University and received W&J's distinguished achievement award in 1988.

Dryden might be the first to document Lyme disease or HGE in Allegheny County ticks.

While Allegheny County residents for years have been diagnosed with Lyme disease -- some claim they could not have been infected elsewhere -- the county health department has yet to encounter an infected tick. The beagle club is an "ideal laboratory," health department spokesman Guillermo Cole said.

The 75-member beagle club, the nation's second oldest, was founded in 1895 and has owned the West Deer preserve since 1950. The club nurtures the rabbit population by providing food and habitat, secretary Dave Bagaley said.

Because dead rabbits have been found with numerous ticks, Bagaley said, members want to know what's going on. If the rabbit ticks carry human diseases, Cole said, club members need to take precautions.

"If they're taking their dogs out there, these people obviously will be at increased risk, and they should dress appropriately ... minimize the amount of skin exposed," Cole said.

A club member trapped rabbits and removed ticks for Dryden's review.

Often, however, Dryden and his students hit the woods to collect their own. When they do, they take no chances. They wear white shirts, pants and hats and check each other for ticks every 10 minutes.

"I never would go out collecting by myself," Dryden said.

To keep ticks from getting under their clothes, he and his students put duct tape around their wrists, ankles and waistbands and along the plackets of their shirts. Dryden also puts duct tape around his collar and puts repellent on his shoes and socks.

He pulls a length of cloth through the underbrush, checking each side periodically to see whether he's picked up ticks. Some of his students prefer to gather ticks by waving a piece of cloth through the brush as one would wave a flag.

In the window of Dryden's W&J lab is a sign saying "Ticks-R-Us."

There, the ticks are crushed and their DNA extracted. To get more material to work with, the researchers add chemical "primers" and put the mixture in a "thermal cycler" that increases the amount of diseased DNA.

The mixture then is placed in a gel, given an electrical charge and photographed under ultraviolet light. If Lyme disease or other pathogens are present, the DNA moves in the gel and is captured in the photographs, Dryden said.

Besides gathering ticks in Erie County in northwestern Pennsylvania, he and his assistants have analyzed ticks that University of Pennsylvania researchers provided from Delaware and Chester counties in the southeast. W&J's work has been supported, in part, by a grant from the Howard Hughes Medical Institute in Chevy Chase, Md.

Jan Humphreys, biology professor at Indiana University of Pennsylvania, said Dryden's project has provided insights on the distribution of deer ticks and tick-borne diseases statewide.

"He has certainly been able to show what we call hot spots," said Humphreys, who has studied the black bear's role as a carrier of Lyme disease and HGE.

W&J may be the only school in the state checking ticks for human diseases.

"Not a whole lot of this tick-borne research has been done in Pennsylvania," Dryden said.

The state Health Department tracks cases of Lyme disease, but not HGE or bebesiosis, a third tick-borne illness Dryden has begun studying.

His team has found the heaviest concentration of Lyme disease in the northwest and the heaviest concentration of HGE in the southeast. Ominously, high percentages of ticks from each area tested positive for Lyme disease and HGE -- perhaps the first reports of "co-infection" in the state, Dryden said

Dryden said that's important information for physicians because the diseases, which can be transmitted by a single bite, require different treatments. Echoing findings in other states, Dryden also has documented in Pennsylvania a strain of HGE that doesn't sicken humans.

Just as important as the findings, Humphreys said, is the impact of Dryden's work on students.

Dryden has sent Courtney and two other W&J students -- an unusually high number -- on internships at the CDC. After graduating last year, Courtney returned to the CDC on a fellowship and helped write an article for the agency's Journal of Emerging Infectious Diseases.

"That's a classic example of the type of student coming out of his program down there," Humphreys said.

Dryden said his research has shown southwestern Pennsylvania to be a "wonderful, wonderful" place to live. He's scoured four farms and found only a few deer ticks, none of which carried Lyme disease or HGE. He said the dog ticks more prevalent in this area don't appear to carry the diseases.

Of course, there's still the question of danger posed by rabbit ticks in Allegheny County. Dryden said the rabbits could be sick because the ticks have taken so much blood from them or because the ticks have infected them with a disease.

The unknown, Humphreys said, draws him and Dryden to their work. "We like solving mysteries," Humphreys said.