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NLM Director’s Comments Transcript
Lyme Disease Recurrence Is a New Infection – Not a Relapse: 12/10/2012

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Greetings from the National Library of Medicine and

Regards to all our listeners!

I'm Rob Logan, Ph.D. senior staff National Library of Medicine for Donald Lindberg, M.D, the Director of the U.S. National Library of Medicine.

Here is what's new this week in MedlinePlus.listen

Lyme disease’s recurrence is a new infection rather than a relapse, suggests research based on DNA sequencing recently published in the New England Journal of Medicine.

The study followed 17 patients who had a Lyme disease reappearance between 1991 and 2011. The researchers sequenced a gene cultured from a patient’s skin or blood samples. The gene was from the same strain of an outer-surface protein that occurs within Lyme disease’s initial stages. The researchers tested at least 22 samples taken from patients that spanned their first and second Lyme disease episode — and used similar procedures if the disease reoccurre.

All participating patients experienced Lyme disease at least twice during the study's time period. All participants were treated and recovered.

The authors reported in 16 of the 17 patients who experienced a recurrence of Lyme disease, a comparison of the DNA sequences showed the underlying genotypes did not match. While the DNA sequences matched in the first and third infection for one of the participating patients, the genotypes for this person were different in the disease’s second and fourth occurrence.

The authors conclude (and we quote): ‘our data show that repeated episodes … in appropriately treated patients were due to reinfection and not relapse’ (end of quote).

The study’s authors explain the ability to distinguish whether a recurrence of Lyme disease is a new infection or a relapse is important because previous tests could not make this discrimination. 

An accompanying editorial by Allen Steere M.D., the physician who discovered and named Lyme disease, suggests the study’s findings also clarify some issues regarding the continuation of antibiotic treatments for chronic Lyme disease patients. Steere writes (and we quote): ‘the issue of relapse versus reinfection has a broader context because of patient-advocacy groups that promote months or years of antibiotic therapy for “chronic Lyme disease”’ (end of quote).

Steere explains the study suggests there may be less persistence of the same infection for chronic Lyme disease patients, which suggests antibiotic treatments might be interspersed more effectively.

To provide a little background,’s Lyme disease health topic page explains the disease is caused by a bacterium that is carried by deer ticks. Lyme disease often first appears as an area of red skin around a tick bite that often looks like a bull’s eye. The infection can appear in different areas of the body.

While Lyme disease often is treated with an antibiotic called doxycycline, symptoms such as fever, headaches, and fatigue can linger.’s Lyme disease health topic page explains if untreated, the disease can lead to arthritis as well as heart, and neurological problems. An estimated 20,000 to 30,000 Lyme disease cases occur in the U.S. annually. The disease is more prevalent in the Northeastern region of the U.S.

A guide to Lyme disease prevention (provided by the American College of Physicians) is available in the ‘prevention/screening’ section of’s Lyme disease health topic page. A helpful review of the treatments for Lyme disease (edited by Dr. Steere and provided by UpToDate) is available in the ‘treatment’ section of’s Lyme disease health topic page.’s Lyme disease health topic page also contains links to the latest pertinent journal research articles, which are available in the ‘journal articles’ section. Links to related clinical trials that may be occurring in your area are available in the ‘clinical trials’ section. From the Lyme disease health topic page, you can sign up to receive email updates with links to new information as it becomes available on MedlinePlus.

To find’s Lyme disease health topic page, type ‘Lyme disease that’s L…Y…M….E’  in the search box at the top of’s home page. also has a health topic page devoted to tick bites, which is accessible by typing ‘tick bites’ in the search box at the top of’s home page. Information about doxycycline is available in the ‘drugs/supplements’ section accessible from’s home page.

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