Bartonella spp. Bacteremia and Rheumatic Symptoms in Patients from Lyme Disease–endemic Region

摘要

To the Editor: We believe the recent article by Maggi et al. (1) contains serious fl aws in content and underlying message, including a poorly defi ned study population, lack of appropriate controls, improper use of the term bacteremia, and incongruent laboratory fi ndings. Selection criteria were vague: the authors state only that participants were a “biased” collection of “patients selected by a rheumatologist,” with no control population included for comparison. The diagnosis of Lyme disease and other previously diagnosed conditions was solely by self-report. Although blood samples were collected from every participant, the authors apparently neglected to perform standardized testing for Borrelia burgdorferi or other conditions. The term “bacteremia” signifi es presence of viable bacteria in the bloodstream, which is not substantiated solely by a positive PCR result. True bacteremia was documented in only 1.7% of participants from whom a viable Bartonella species isolate was cultured, rather than the purported 41.1% of participants. Surprisingly, many participants whose PCR results were positive for Bartonella spp. had no serologic evidence of infection (e.g., 82.5% of samples that had positive PCR results for Bartonella henselae were not seroreactive). Although anergy has been reported, samples from most immunocompetent and immunocompromised patients infected with Bartonella spp. are seroreactive (2–4), calling into question the authors’ fi ndings. Furthermore, 24% of samples that were positive by PCR revealed no identifi able Bartonella spp. by DNA sequencing; these participants should have been excluded from analysis.