Researchers have conducted an experiment to figure out whether uninfected ticks could lead to diagnosis of a persistent Lyme infection in people. It was found that the DNA from the Lyme parasite was transmitted to the ticks from only two people among more than 20 people who were suffering from lingering Lyme infection.

Lyme disease is transmitted through the bite of an infected tick. About 10-20% of people who contract Lyme disease are not able to get rid of the pain, fatigue or aches even after receiving the proper treatment and showing signs that the infection is gone. The symptoms can last for over six months and are known as Post-Treatment Lyme Disease Syndrome (PTLDS).

In the new study, the researchers performed the second-bite system on people with PTLDS. Of 36 participants, 26 showed persistent symptoms after getting treatment for Lyme disease, or still had an itchy, red lesion at the site of the original bite, or had high levels of antibodies against the infection.

About 25 to 35 uninfected ticks were placed on the arms of each person to feed for few days. Not even a single tick from healthy volunteers had showed any signs of the Lyme bacteria, but the results were unclear for two people. The researchers will now try to check in detail regarding the persistent symptoms with the help of further studies.

Lead author Dr. Adriana Marques of the National Institutes of Health in Bethesda, Maryland, said, "This is a very initial study, our main objective was to develop the technique in humans. It is very hard to find evidence of the bacteria itself, not just antibodies, in infected people once the skin rash is gone". She, however, said the tick method can make this process easier with the help of further researches.

After conducting the animal study previously, researchers said xenodiagnosis, or diagnosis with another animal, was successfully used to detect the signs of a persistent Lyme infection in the blood. The technique has also been successfully used for detection of another parasitic infection, Chagas disease.

It was seen during animal tests that mice and monkeys were infected with Lyme disease and the given treatment until no sign of Lyme bacteria was detectable in their blood. If an uninfected tick bit the animal and Lyme bacteria turned up in the tick, it meant that the animal was still suffering from the infection.