Comparison of the tuberculin test, histopathological examination, and bacterial culture for the diagnosis of tuberculosis (Mycobacterium bovis) in buffaloes (Bubalus bubalis) in Brazil.

Tuberculosis is a disease with a great zoonotic potential. It is considered a major obstacle to cattle production and is responsible for severe losses in several production systems. A comparative cervical test (CCT) was performed in 1140 buffaloes from different mesoregions of the state of Pará, Brazil, with the aim of comparing the sensitivity and specificity of CCT with histopathological examination and bacterial culture. Of the animals tested using CCT, 4.65% (53/1140) were positive, 2.98% (34/1140) were inconclusive, and 92.36% (1053/1140) were negative. Among the 168 sacrificed animals, 33 were positive, 18 were inconclusive, and 117 were negative by CCT, and samples from the sacrificed animals were collected for histopathological examination and bacterial culture. A qualitative evaluation of the tuberculin test was performed by comparing the test results with the histopathological and bacteriological results. The latter two tests yielded a prevalence of 4.16%, a sensitivity of 71.43%, and a specificity of 82.61%. Based on these results, we concluded that CCT yielded satisfactory results and can be applied in diagnostic studies in buffaloes. The prevalence rate obtained using three distinct diagnostic methods suggests that Mycobacterium bovis was present in a few animals in the population evaluated.

Serological survey and risk factors for brucellosis in water buffaloes in the state of Pará, Brazil.

To evaluate the prevalence and possible risk factors for brucellosis caused by Brucella abortus in water buffaloes in the state of Pará, Brazil, 3,917 female buffalo serum samples from pregnant and non-pregnant animals were examined: 2,809 from Marajó Island and 1,108 from the mainland. The buffered acidified plate antigen (BAPA) screening test positively diagnosed 4.8% (188/3,917) of the animals with brucellosis, and the 2-mercaptoethanol (2-ME) confirmatory test affirmed 95.7% (180/188) of the results. The brucellosis prevalence was 4.17 times greater in mainland animals than on Marajó Island, with the highest prevalence in Tailândia (11.30%) and Paragominas (12.38%). Brucellosis seroprevalence was significantly influenced (p < 0.05) by reproductive status, with pregnant females being most vulnerable. These results demonstrate that brucellosis infection is active in the Brazilian region containing the largest buffalo population and that this disease poses a threat to public health and buffalo production in Pará.