Lyme Disease Experimental Xenodiagnosis Method Tested on Humans For First Time

A new experiment has shown limited yet promising results in which humans are diagnosed for persistent Lyme disease by an uninfected tick.

Out of the 12 participants, Reuters reported, two patients' Lyme parasite DNA was transferred to a tick that did not previously carry the infection. Ticks are a vessel for spreading Lyme disease to humans.

Published in the journal Clinical Infectious Diseases, the study represents the first time scientists have attempted "xenodiagnoses" on a human subject. Xenodiagnosis, in animal studies, is when another animal is used to reach a diagnosis.

"This is a very initial study, our main objective was to develop the technique in humans," study lead author Dr. Adriana Marques, of the National Institutes of Health in Bethesda, Maryland, told Reuters. "It is very hard to find evidence of the bacteria itself, not just antibodies, in infected people once the skin rash is gone."

Xenodiagnosis has been successful in animal tests when diagnosing persistent Lyme infections. The technique has also been successful in humans when diagnosing Chagas disease, a similar parasitic infection.

Most people who get Lyme disease are done with it after a few weeks of antibiotics and are often completely healthy again by the fourth week. Still, about 10 to 20 percent of people who get Lyme disease say they experience fatigue, pain and aches after the infection should have left them.

These symptoms can be felt up to six months after contracting the infection, a condition known as Post-Treatment Lyme Disease Syndrome (PTLDS).

"There is consensus that post-Lyme disease syndrome as defined in the paper does exist and that it occurs in a minority of people," study editorial co-author Linda K. Bockenstedt, of Yale University School of Medicine, told Reuters. "We do not know why this occurs, and the reasons may not be the same for everyone."

The research team's objective was to test to determine if the xenodiagnosis method is safe for humans. The next objective will be to connect the diagnosis method to persistent symptoms.