To address the effect of serum treatment with chloroform (STC) on increasing the specificity of the Rose Bengal test (RBT), 200 serum samples (n=100 buffaloes and n=100 cows) were tested. For each animal species, 50 were apparently healthy and 50 were aborted. RBT and indirect enzyme-linked immunosorbent assay (iELISA) were applied for testing the serum before and after treatment with chloroform. The coherence between tests was poor (K=0.004, SE=0,003), (K=0.031, SE=0.24) and (K=0.176, SE=0,143) for apparently healthy buffaloes, apparently healthy cows and aborted buffaloes respectively, but it was only fair (K=0.386, SE=0,185) for aborted cows. After STC, the coherence between tests was markedly improved, where it became perfect (K=1.0, SE=0.0), (K=0.834, SE=0.113) and very good (K=0.896, SE=0.071) for apparently healthy buffaloes and cows, aborted cows and aborted buffaloes. The specificity and sensitivity of RBT were obviously raised after STC recording (100% and 100%), (80% and 100%) and (75% and 100%) for apparently healthy buffaloes and cows, aborted buffaloes and aborted cows respectively. Current results recommended that STC is a reliable method to avoid false positives. The higher specificity and sensitivity obtained by RBT after using STC suggests that it is not only can be used as a rapid, simple, economical and convenient screening method but also it can be used as a confirmatory test for serodiagnosis of brucellosis for large scale in endemic areas.
Brucellosis, Chloroform, RBT, Serum treatment, Specificity.