The main point of the article as taken from the title is the ability of the LTT to detect active infection and the effect of antibiotic treatment. However, owing to the study design, evidence of active infection is lacking. Clinical features, including follow-up and/or detection of the organism by culture or PCR, are absent. Also, the conclusion that the Borrelia LTT may be used for follow-up monitoring of disseminated B. burgdorferi sensu lato infections and provide indications for antibiotic treatment is not supported by the study design, as this would require a prospective trial with a control group. Thus, the LTT paper contains methodological shortcomings with a risk of selection bias, and the study design and the data do not support the content of the title or the conclusions about the diagnosis of active infection or measurement of treatment effect. There are several issues that need clarification in order to allow valid conclusions to be drawn about the Borrelia LTT.