Suitability of various Coxiella burnetii antigen preparations for detection of serum antibodies by various tests.

Comparison of four serological tests (complement fixation (CF) test, microagglutination (MA) test, microimmunofluorescence (MIF) test, and enzyme-linked immunosorbent assay (ELISA)) for detection of post-infection antibody response in human and animal sera revealed a low sensitivity of the CF test with acute Q fever human, goat and sheep sera but not with chronic Q fever human sera and sera of aborting cows. The remaining three tests gave similar results with human (both acute and chronic) and cow sera, but the ELISA was more sensitive than the MA and MIF tests with goat and sheep sera. A treatment of phase I Coxiella burnetii (C.b.) cells with chloroform-methanol, potassium periodate and trichloroacetic acid (TCA), and mild acidic hydrolysis did not result in increase of the sensitivity of the tests when compared with the natural phase I and phase II C.b. cells, respectively. The suitability of various C.b. antigen preparations for the abovementioned serological tests with various sera is discussed.