Resumo

Animal brucellosis is still an important problem in Latin America and also a zoonosis. Conventional test has been used worldwide for diagnosis of diseases which are not able to differentiate S19 vaccinated cattle from infected cattle. Fluorescence polarization (FPA) is a test that has been developed for serological diagnosis of brucellosis and many countries began to incorporate it for their brucellosis program. Our objective is to show the FPA performance on diagnosis in S19 vaccinated cattle and buffaloes. Methods: Test other than FPA used in this study were, buffer plate antigen (BPA), Complement Fixation (FC), Indirect and Competitive ELISA. Serum samples classified in 5 groups: 1) 200 negatives, 2) 200 positives, 3)1500 from herds of brucellosis routine surveillance having between 5 and 10% of infection, and 4) 1000 from negative cattle taken 6 months after vaccination. 5) 250 Strain 19 vaccinated water buffaloes). A Portable Diachemix Sentry 100 instrument (single tube reader) was used for FPA reading. Results: All tests detected 100% of negative animals and positive animals, group 3: 678, 499, 669, 503 and 506; group 4: 156, 29, 71, 9 and 10; group 5: 75, 80, 60, 19, 11 were positives for BPA, FC, IELISA, CELISA and FPA respectively. We show some of the advantages for the implementation of FPA technology. In positives and negatives animal all tests perform very well; however in 19 vaccinated cattle as well as in water buffaloes, the performance of FPA and CELISA was excellent. In conclusion, FPA technology have several advantages for being used for brucellosis diagnostic, it is a low-cost and easy-to-perform test, can be used as a screening and/or confirmatory test according to the prevalence, and it is not affected by vaccination, thus reducing the number of misdiagnosed and killed animals.