Lyme Disease bacteria not a newcomer

WASHINGTON — Lyme Disease was identified as an ailment only 15 years ago, but the bacteria that cause it have been around at least since the early 1940s, says a Yale University researcher who scoured museums for embalmed remains of ticks that spread the disease.

Before 1975, when an outbreak in Old Lyme, Conn., gave the disease a name, residents of Long Island may have known it as “Montauk knee” or “Montauk spider bite,” said Dr. David Persing.

Lyme Disease, a potentially crippling but rarely fatal condition, is spread to humans by the bites of ticks infected by spiral-shaped bacteria called spirochetes. The ailment afflicts 6,000 people each year and can progress from malaise and fatigue, chills and fever, to painful and chronic arthritis, neurological problems and heart damage.

“We suspected that the spirochetes had been around in the United States, sort of hiding away, long before Lyme Disease became identified as a clinical entity,” said Persing, who left Yale a month ago to become a clinical pathologist at the Mayo Clinic in Rochester, Minn.

“The first accounts of what we think were Lyme Disease were recorded around 1910 in Europe and, later in the century, European physicians noticed tick bites were related to neurological symptoms,” Persing said. “They also recognized tick bites related to skin rashes.”

The question facing the researchers was whether the Lyme Disease spirochete was simply missed in medical diagnoses before 1975 or whether it’s that new to the American continent and could increase.

The research is described in Friday’s issue of Science magazine. Persing and his colleagues found that a method of detecting spirochetes in ticks — using a test to find genetic material called DNA in the germ — worked as well with dried or alcohol-preserved specimens.

“So we scoured local museums for the presence of ticks stored in alcohol since the 1940s,” he said in an interview. “In those days, entomologists would go out and collect ticks, trying to determine their feeding behavior. They put them into repositories to be analyzed later.

“They never knew these ticks, some day, long after the investigators passed away, would be crushed up and tested for the DNA within them,” he said.

The Yale researchers got more than 150 preserved specimens dating back to 1925, from a museum at Harvard and from the Smithsonian Institution. Thirteen of them tested positive for the presence of the Lyme spirochete. All the positive ticks came from Long Island.

There also were tick specimens that came from Florida, South Carolina and California. None tested positive for the Lyme Disease spirochete.

The detection method used by the researchers will now be used on blood samples taken from humans and may improve physicians’ ability to diagnose the disease, Persing said. It may be useful in following patients who are being treated.

As for the patients who had “Montauk knee” and similar mysterious ailments, Persing said, they didn’t fare so badly.

“Many of the physicians I talked with treated skin manifestations with penicillin, which is effective for Lyme Disease in its early stages,” he said. “It’s interesting they most likely treated appropriately even though they didn’t know it was caused by an infectious agent.”