According to Bull's Eye: Unraveling the Medical Mystery of Lyme Disease, Kary's new invention, developed in 1983 - Polymerase Chain Reaction (PCR) - was instrumental in learning more about Borrelia burgdorferi's history:
"One medical researcher who was quick to apply this technique in the medical arena was Dr. David Persing, then at the Yale University Department of Pathology. Being at Yale, Persing was interested in Lyme disease. Among many other projects, he and colleagues used PCR on 102 dried-out or alcohol-preserved tick specimens from the Museum in Comparative Zoology in Cambridge, Massachussetts. The ticks had been collected from various areas in New England between 1945 and 1951; each was tagged with the exact location where they had been collected. The researchers also examined another batch of ticks from the Smithsonian collection in Washington, D.C., some dating back as far as 1924. They found ticks that were positive for the DNA of B. burgdorferi from Montauk Point and from the adjacent Heather Hills State Park from the mid-1940s.
Several years later, the same group with additional colleagues reported the results of similar experiments done on tiny biopsy specimens taken from the ears of archived mice from the same museum. They found two specimens that tested positive by PCR anaylsis for B. burgdorferi from mice orginally captured near Dennis, Massachusetts (on Cape Cod), in 1894! The DNA from these specimens was identical to the B31 strain that Willy Burgdorfer had found on Shelter Island.
European investigators have reproduced these experiments using archived ticks from various parts of Europe including England and have found borrelial DNA dating back to the late 1880s as well. If the Lyme spirochete had been around for so long, why did it begin to surface as a recognized medical entity only in the past few decades? This question can be answered in one word --- deer."
I always find history fascinating, especially the connections between technology and information gathering. Here the PCR was invented around shortly after the time that news that Borrelia burgdorferi was the agent of Lyme disease was published in Science in 1982. We know far more about Bb now than we would have if this (or a similar technology) had not been developed at the time it was.