Chronic Q Fever: Different Serological Results in 3 Countries--Results of a Follow-up Study 6 Years After a Point Source Outbreak

Abstract

This study has shown that the results from Q fever micro-immunofluorescence vary according to the center in which they are carried out. This has implications for the interpretation of such tests, raises questions regarding the validity of using serological criteria alone as a means of diagnosing chronic Q fever, and affects the interpretation of epidemiological studies. We recommend that all results are interpreted according to the clinical picture and particular caution is applied in the interpretation of chronic serological profiles. In order to further our understanding of Q fever infection we propose that an international standard of Q fever serological investigation be developed.

18F-FDG PET/CT as a central tool in the shift from chronic Q fever to Coxiella burnetii persistent focalized infection

“…[25] DNA was extracted using the QIAamp Tissue Kit (QIAGEN GmbH, Hilden, Germany), and these extracts were used as templates for PCR amplification as previously described. [26] Culture, immunohistochemistry, and fluorescent in situ hybridization (FISH) targeting C burnetii 16S rRNA were performed.…”

Chronic Q fever: Expert opinion versus literature analysis and consensus

“…22 In addition, the methods of diagnosis are heterogeneous, and several works have shown that the marketed tests and in-house tests could have important divergences, even if these differences are relatively few. 23 It should be noted that serologies against phase II C. burnetii for Focus Ò slides generate titers that are much higher than those obtained at the National Reference Centre (unpublished). In practice, a recent work by Frankel et al from my lab, based on 179,000 serological samples, shows that the current positive predictive values of anti-phase I IgG have increased from 800 (37%) to 6400 (75%).…”

Coxiella burnetii causing haemophagocytic syndrome: a rare complication of an unusual pathogen

“…Immunofluorescence, despite remaining the reference method for confirming the diagnosis by serology, is not well standardised across laboratories. Wide variations in reported antibody titres are known from studies that have compared sera tested in different countries [26]. As such, doubt exists as to whether a high phase 1 IgG titre alone is sufficient evidence for the diagnosis of chronic Q fever.…”