EVALUATION OF THE ROSE BENGAL PLATE TEST, IN COMPARISON TO THE COMPLEMENT FIXATION AND MERCAPTOETHANOL TESTS, FOR THE SERODIAGNOSIS OF BRUCELLOSIS IN A Brucella abortus INFECTED BUFFALO (Bubalus bubalis) HERD.

M. R. A. PINTO, J. J. FAGLIARI, L. A. MATHIAS, J. MEGID, V. R. SALGADO

Abstract


The purpose of this investigation was to evaluate the rose Bengal plate test (RBPT) for brucellosis serodiagnosis in a Brucella abortus infected buffalo (Bubalus bubalis) herd, comparing the results with those obtained by the mercaptoethanol (MET) and the complement fixation tests (CFT). Serum samples from 90 three-to-five-years-old cows were collected. Animals were unvaccinated against brucellosis. Every serum was tested by the three serological tests, and the results were compared by kappa (k) and the MacNemar chi-square, adopting as cutt-off the titre 25 for the MET and the titre 4 for the CFT. A good agreement was observed among the tests (RBPT versus CFT, k = 0.82; RBPT versus MET, k =0.92; MET versus CFT, k = 0.86), and the chi-square did not show significant difference. The relative sensitivity of the RBPT, when compared with the combination of the results of MET and CFT, was 93.03%, with a confidence interval (95%) ranging from 87.57% to 98.47%. Out of 43 animals considered infected by the combination of the results of the two other tests, three tested negative by the RBPT, suggesting the possibility of occurrence of false-negative results.
KEY-WORDS: Brucellosis. Bubalus bubalis. Serodiagnosis. Rose Bengal plate test. Complement fixation test.
Mercaptoethanol test.



DOI: http://dx.doi.org/10.15361/2175-0106.2005v21n4p147-154