Aim: To introduce and validate the new method of diagnosing ovine and caprine brucellosis in a rapid, accurate and inexpensive manner by using i-ELISA (serum/milk) technique.
Methods: Serum and milk samples from brucella RB and CFT negative (n=881) and positive (n=755) animals were used. Standardization of tests was through the Bommeli ELISA-BESW (Brucella Bang) standard and our Institute's (MKD) working standards (positive serum and milk based on B. melitensis antigen).
Results: Validation of serum/milk ELISA for detecting ovine and caprine brucellosis was completed. The specificity obtained for the serum ELISA was 99.0% for the Bommeli system (at cut-off of 30% of positivity--PP) and 99.4% for the MKD system (at cut-off 15% PP). The sensitivities of serum ELISAs at the same cut-off were 98.5% for the Bommeli and 96.6% for the MKD test. Parallel milk samples from the same animals showed a specificity of 99.5% in the Bommeli system (at cut-of 30% PP) and 99.8% in the MKD system (at cut-off 25% PP). The sensitivity of the milk ELISAs were 94.6% for the Bommeli test and 95.6% for the MKD test.
Conclusion: The Bommeli ELISA and MKD ELISA were successfully standardized and validated as confirmatory tests for the diagnosis of B. melitensis in sheep and goat samples (milk/sera). Using our Institute's milk standard, we confirmed successful screening of brucellosis in pooled milk samples from 100 sheep and 100 goats.