Comparison of two commercially available ELISA antibody test kits for detection of human antibodies against Coxiella burnetii

Abstract

Background: Q fever is a zoonosis caused by Coxiella burnetii. The disease is emerging in many parts of the world, likely in part due to increased awareness and the availability of better diagnostic tests. The clinical diagnosis of Q fever is difficult, and most confirmed cases rely on serology. Methods: This study compared the sensitivity, specificity, and performance of 2 commercial enzyme-linked immunosorbent assay (ELISA) kits, with a commercial microimmunofluorescence antibody test (IFA) used as reference. Results: One of the ELISA kits showed a higher sensitivity and a lower cross-reactivity than the other kit. Likewise, the same kit was superior when comparing the area under the receiver operating characteristic curves. Conclusions: The results support the continued use of IFA as a primary serological test for Q fever; for large numbers of samples, an ELISA kit can be used as a screening tool, if followed by a confirmatory IFA test.

Keywords::

• Coxiella burnetii
• Q fever
• serology

Acknowledgements

Laboratory technician Christian Haraldsen is thanked for meticulous sample processing and skilled technical assistance in the laboratory. Marian Jørgensen is thanked for proofreading of the manuscript.

Declaration of interest: None of the authors have conflicts of interest regarding this manuscript. The suppliers of the test kits did not have any influence on the design and conduct of the study. The manuscript has been produced without input from the test kit suppliers.