Persistence of DNA in a Cured Patient and Positive Culture in Cases with Low Antibody Levels Bring into Question Diagnosis of Q Fever Endocarditis

摘要: We evaluated the performance of tools for diagnosing Q fever cardiovascular infection. retrospectively analyzed 162 samples from 125 patients who were tested serologically by immunofluorescence, quantitative PCR (qPCR), 16S rRNA gene amplification, culture, and immunohistochemistry, we assessed viability Coxiella burnetii measuring transcription gene. The qPCR technique was significantly more sensitive than amplification (P < 0.0001), cell culture = 0.0002), immunohistochemistry 0.0001). sensitivity these techniques reduced when applied to had been previously treated. severity infection appears be correlated with phase I IgG levels. report first time 4 cases endocarditis positive and/or assay result a low (IgG I) titer (<800), have identified longest (16 years) persistence DNA described in heart valve patient cured after being treated endocarditis. active found 19/59 samples, predictive value 100% culture. In conclusion, diagnosis should not excluded titers they present valvulopathy. recommend testing using 3 or different biopsy sections evaluation ≥200.