Table 2.

Sensitivity, specificity, and positive and negative predictive values of different serological tests for diagnosis of Q fever

TestForm of diseaseTiterSensitivity (%)Specificity (%)Positive predictive value (%)Negative predictive value (%)Reference
MicroimmunofluorescenceAcuteAnti-phase II IgG, ≥1:200; anti-phase II IgM, ≥1:5058.492.2NAa 88–96.6 181
ChronicAnti-phase I IgG, ≥1:800100NA98.6NA 181
Anti-phase I IgG, ≥1:1,600NANA100NA 181
ELISAAcuteAnti-phase II IgG, ≥1:1,02480>99NANA 191
Anti-phase II IgM, ≥1:51284
Acute (screening)Anti-phase II IgG, ≥1:128; anti-phase II IgM, ≥1:128NA97.3–98.7NANA 191
MicroagglutinationAcute1:6481.698.6NANA 123
  • a NA, not available.