New Lyme Disease Test Shows Promise

A test using uninfected ticks to detect persistent Lyme disease in human has shown promising results, according to a recent study.

The study, published in the Oxford journal Clinical Infectious Diseases, provides the results of the first scientific attempt to use xenodiagnosis to detect Lyme disease causing bacteria.

Xenodiagnosis is the use of animals to determine the presence of a specific disease or illness. In this study, researchers used uninfected ticks -- I. Scapularis larvae -- to diagnose patients who were suspected to have persistent Lyme disease even after treatment.

For most victims of Lyme disease, about a month of antibiotic treatment eliminates the bacteria in the blood that caused the initial infection. Four weeks into treatment, patients with no signs of the bacteria are considered cured. However, approximately 15 percent of people who contract Lyme disease report to have the symptoms of infection even after the bacteria appear to be gone.

According to authors of the study, this latest technique was designed to help make finding of the bacteria associated with Lyme disease in a patient much easier, determining once and for all if the disease has been truly cured after initial treatments. Prior to this study, it has proven extremely difficult for medical professionals to diagnose persistent Lyme disease because of the difficulty associated with finding the Lyme disease bacteria. Instead, most professionals would resort to looking for active antibodies, indicating if the body is still attempting to fight off the disease. However, such a test is time consuming and infamously inaccurate.

In this latest study, researchers tested 36 participants for persistent Lyme disease using the xenodiagnosis approach. Twenty-six of these participants had shown signs of Lyme disease even after initial treatments appeared to have eliminated all of the bacteria-at-fault. The other ten participants were healthy individuals who never had the disease.

Researcher let 20 to 30 uninfected ticks feed on the arm of each participant. The ticks were then retrieved and left to incubate, potentially growing a Lyme disease bacteria colony within their bodies if they happened to receive the bacteria from a participant in the course of their feeding.

Of the 26 patients complaining of persistent Lyme disease symptoms, two produced ticks that tested positive for the Lyme disease bacteria after feeding. Of the ten healthy patients, none produced infected ticks.

While two of 26 is not exactly groundbreaking, the results do show that the technique can work, with modest success, where traditional testing had failed. What's more, the study's authors wrote that the fact these initial tests proved entirely safe means that further testing on a larger scale could now be done.

The study was published in Clinical Infectious Diseases on February 11.