Failure rates still too high for treatment of Lyme disease

In a recent study, Wormser and colleagues reviewed the cases of 24 adult patients with erythema migrans, who received a 14-day course of amoxicillin, 500 mg 3 times daily to determine the treatment efficacy and safety. The authors concluded that this single course of antibiotics was “highly effective” for treating early Lyme disease. Unfortunately, the failure rates are still too high.

According to the authors, the 14-day course effectively cleared the patients’ erythema migrans rashes and “prevented the development of objective neurologic, cardiac, or rheumatologic manifestations.” One patient was retreated with amoxicillin. Two others could not be evaluated at 1-year follow-up due to a recurrent erythema migrans (EM) rash.

But 4 out of the 24 patients went on to develop “Post-treatment Lyme disease Syndrome” (PTLDS). Individuals with PTLDS have had “subjective symptoms attributed to Lyme disease that had persisted continuously or intermittently for at least 6 months following completion of antibiotic treatment with amoxicillin,” writes Wormser from New York Medical College in the journal Diagnostic Microbiology and Infectious Disease.

This failure rate is arguably still too high for patients presenting with an EM rash.

The actual failure rate with a 14-day course of treatment might be higher in patients who have a delay in treatment, suffer from more severe symptoms and/or have co-infections with other tick-borne pathogens.

Editor’s note: “PTLDS” remains a controversial term that I do not endorse, given that there is no test to prove the Lyme infection has cleared.