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Updated: May 2, 2026

The Development of Lyophilized Loop-mediated Isothermal Amplification Reagents for the Detection of Coxiella burnetii
Published on: April 18, 2016
Immunogenicity of the Q fever skin test
Teske Schoffelen1, Tineke Herremans2, Tom Sprong3
1Department of Internal Medicine, Radboud University Medical Center, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
Objectives:
The Q fever skin test is used to measure cell-mediated immunity to Coxiella burnetii in pre-vaccination screening to exclude individuals with pre-existing immunity. We investigated whether this in-vivo test influences subsequent measurements of immune response.
Methods:
We assessed the humoral and cellular immune responses before, and 6 and 12 months after skin testing in 63 individuals who were not vaccinated because of either a positive skin test or positive serology in screening. IgG anti-C. burnetii antibodies were measured using immune-fluorescence assay (IFA). The cellular immune response was assessed by measuring in-vitro C. burnetii-specific interferon (IFN)-γ production in blood.
Results:
Of the 35 subjects with a positive skin test and negative serology, 15/35 (43%) showed seroconversion at 6 months, and 7/32 (22%) seropositivity at 12 months. The mean ± SE specific IFN-γ production in this group increased from 185 ± 88 pg/mL (at baseline) to 422 ± 141 pg/mL at 6 months (P = 0.009) and 223 ± 91 pg/mL at 12 months (P = 0.17). Of the 28 subjects with positive serology (and unknown skin test results), 21/28 (75%) showed an increase in IgG anti-phase I titres at 6 months, and 11/25 (44%) at 12 months. The mean ± SE specific IFN-γ production was significantly increased at 6 months, but not at 12 months.
Conclusions:
Q fever skin testing causes higher antibody titres and higher in-vitro IFN-γ to C. burnetii, and therefore affects subsequent Q fever diagnostics.

