SENSITIVITY AND SPECIFICITY OF THE COMPLEMENT FIXATION TEST FOR DETECTION OF CATTLE PERSISTENCY INFECTED WITH ANAPLASMA MARGINALE

Authors: BRADWAY, D. - WASHINGTON STATE UNIV; TORIONI DE ECHAID, S. - WASHINGTON STATE UNIV; Knowles Jr, Donald; HENNAGER, S. - APHIS; MC ELWAIN, T. - WASHINGTON STATE UNIV

Submitted to: Journal of Veterinary Diagnostic Investigation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/15/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary: This manuscript provides for performance data for the complement fixation test for the detection of anti-Anaplasma marginale antibody in cattle. The data show that this test has extremely poor sensitivity (20%). This is important since this is the commonly used test for detection of this antibody and used for restricting the movement of cattle to Canada

Technical Abstract: The complement fixation (CF) test commonly is used to identify cattle infected with Anaplasma marginlae prior to interstate or international movement. Estimates of the accuracy of the CF test in detecting animals persistently infected with A. marginle vary widely. In this study, the sensitivity and specificity of the CF test for detection of carrier animals was determined using serum from 232 cattle previously defined as A. marginlae positive or negative by nested polymerase chain reaction methods and hybridization. Considering results from 2 independent laboratories and interpreting a 1:5 suspect reaction as positive, the best estimate of CF test sensitivity was 20%, with a specificity of 98%. Using a 1:10 cutoff, sensitivity decreased to 14% and specificity increased to 99%. Results of this study indicate that the CF test is ineffective for identifying cattle persistently infected with A. marginale and thus is inadequate for anaplasmosis regulatory and surveillance programs.