COMPARISON OF PARTICLE CONCENTRATION FLUORESCENCE IMMUNOASSAY TO CARDAND COMPLEMENT-FIXATION TESTS USING ISOLATION OF BRUCELLA-ABORTUS AS THE STANDARD

Serologic test data and bacteriologic culture results from 816 cattle were evaluated. Brucella abortus (field strain or strain 19) was isola ted from 27.3% of the cows. Results of the card test, particle concent ration fluorescence immunoassay (PCFIA), and complement fixation (CF) test were compared. Antibody titers were directly associated with B. a bortus isolation, with the majority (64.7%) of field strain isolations having a PCFIA value of less-than-or-equal-to 0.300 and a CF test res ult of at least 1+ at a 1:160 dilution. The specificity of the CF test was significantly higher than that of the PCFIA (at CF greater-than-o r-equal-to 1:40 and PCFIA less-than-or-equal-to 0.300).