Never before have live, disease-free ticks been used to detect Lyme disease bacteria - until now.
Published in the journal Clinical Infectious Diseases, a new study applies the method of xenodiagnoses, which detects disease-causing microbes indirectly using a natural carrier of the disease. In this case, ticks were used to detect Lyme disease in people whose symptoms persisted after antibiotic therapy.
Lyme disease is the most common tick-borne illness in the United States and is caused by Borrelia burgdorferi bacteria transmitted to people via ticks of the Ixodes genus.
Dr. Adriana Marques, one of the study's leaders, said in a statement that the goal of this trial was to determine if xenodiagnoses is safe to use on people, given that so far it's only been tried on animals.
Thirty-six adult volunteers contributed to the study: 10 of them with post-treatment Lyme disease syndrome (PTLDS); 10 who had high levels of an antibody against B. burgdorferi after antibiotic treatment; five who had a bull's-eye rash and had received antibiotic treatment in the past; one person with the bull's-eye rash who began antibiotic therapy at the time of tick placement; and 10 healthy participants. All agreed to have up to 30 laboratory-bred, disease-free larval ticks placed on them. Then, when four to six days passed, the scientists removed the ticks and analyzed them to determine if the Lyme disease bacteria was present.
In most cases where the volunteers yielded enough blood to conduct tests, there was no evidence of the Lyme disease bacteria. The researchers say that larger studies are needed to ascertain the significance of positive xenodiagnoses results in cases where Lyme disease symptoms continue after antibiotic therapy.
"Future studies are necessary to determine the incidence of positive xenodiagnostic results for B. burgdorferi after antibiotic treatment, if these results represent viable organisms or remnants of infection, and whether these results can be related to ongoing symptoms in patients after therapy for Lyme disease," they wrote in the report.
