Bovine tuberculosis control and eradication in Brazil: Lessons to learn from the US and Australia

Takatani²,

Pasquatti

et al. 2019

Front. Vet. Sci.

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Bovine Tuberculosis (BTB) is an endemic disease in about one hundred countries, affecting the economy causing a decrease in productivity, condemnation of meat, and damaging the credibility on international trade. Additionally, Mycobacterium bovis the major causative agent for BTB can also infect humans causing a variety of clinical presentations. The aim of this study was to determine BTB prevalence and the main risk factors for the Mycobacterium bovis prevalence in cattle and buffalos in Amazonas State, Brazil. Tissue samples from 151 animals (45 buffalo and 106 cattle from five herds with buffalo only, 22 herds with cattle only, and 12 herds with buffalo and cattle) were obtained from slaughterhouses under State Veterinary Inspection. M. bovis were isolated on Stonebrink medium. The positive cultures were confirmed by polymerase chain reaction (PCR) testing. The apparent herd and animal prevalence rates were 56.4 and 5.40%, respectively. Regarding animal species, the apparent prevalence rates were 3% in cattle and 11.8% in buffalo. Generalized Linear Mixed Models (GLMM) with random effect were used to assess the association with risk factors on the prevalence. Species (buffalo), herds size (>100 animals) and the presence of both species (buffalo and cattle) in the herd were the major risk factors for the infection by Mycobacterium bovis in the region. The findings reveal an urgent need for evidence-based effective intervention to reduce BTB prevalence in cattle and buffalo and prevent its spread to the human population. Studies are needed to understand why buffalo are more likely to be infected by M. bovis than cattle in Amazon. Recommendations for zoning, use of data from the inspection services to generate information regarding BTB focus, adoption of epidemiological tools, and discouragement of practices that promote the mixing of cattle and buffalo, were made.

Section: Criteria For Inclusionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Epidemiological Study of Mycobacterium bovis Infection in Buffalo and Cattle in Amazonas, Brazil

Takatani²,

Pasquatti

et al. 2019

Front. Vet. Sci.

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“…Therefore, the success of bTB eradication and control programs is based on early detection and removal of reactors from a herd (6). Routine testing and cull strategy have been applied globally (3).…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, screening-test accuracy is critical to eradication programs. The single intradermal cervical tuberculin (SCT) test or single intra-dermal comparative cervical tuberculin (CCT) test in Europe, the caudal fold tuberculin (CFT) test in North America, Australia and New Zealand (7), and the SCT and CFT tests in Brazil (6), are the prescribed test for international trade (8). From a practical point of view, the diagnostic performance, the feasibility of execution and practicality of each test, as well as the costs and associated biological risks, should be considered for better strategic use (7).…”

Section: Introductionmentioning

confidence: 99%

“…Due to the TST limitations in terms of sensitivity and speci city, the credibility of the diagnosis is frequently questioned given the occurrence of false-positive and false-negative reactions, therefore, it is necessary to con rm reactive animals using other methods, ensuring the reliability of the diagnosis (5,10,6,7). Research continues into the development of new, more accurate, more sensitive tests, less subject to the individual operative performance and subjective interpretation (14,15,16,17,18,19).…”

Section: Introductionmentioning

confidence: 99%

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Study on a supplemental test to improve the detection of bovine tuberculosis in individual animals and herds

Sousa

Viana

et al. 2020

Preprint

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Background With a worldwide occurrence, bovine tuberculosis (bTB) is a zoonotic disease that is difficult to control, mainly due to the lack of a diagnostic testing to detect infected animals at all stages. Furthermore, the current standard diagnostic test, the Tuberculin Skin Test (TST), is logistically difficult and time consuming. To address this challenge, the aim of this study was to evaluate the sensitivity and specificity of a multiplex enzyme-linked immunosorbent assay (ELISA) comparing with the TST used for the diagnosis of tuberculosis in cattle in Brazil. The study included 400 Nelore females raised for beef on five farms, in different municipalities in Brazil. The comparative cervical test (CCT) was done and on the day of inoculation of the Purified Protein Derivative (PPD) blood samples were obtained and stored for further analysis of the ELISA IDEXX™ Mycobacterium bovis immunoassay. Results Lack of agreement between CCT and ELISA IDEXX™ was observed. No diagnosis described as positive reactor on the CCT was positive at the ELISA, indicating two false positive reactors and 22 negative reactors by CCT were positive by the ELISA IDEXX™. The ELISA IDEXX™ showed sensitivity significantly higher than the official CCT and no significant differences in specificity was observed. ELISA also detected infected animals and herds undetected by the CCT. The parallel use of CCT and ELISA increased sensitivity and the feasibility bTB screening, thus improving the cleaning of the herds. Conclusions The results obtained here suggest that the ELISA IDEXX™ may be a supplemental test for the detection of Mycobacterium bovis infection in regions without routine testing and slaughter, where the disease generally progresses to more advanced stages and antibody responses are likely to be more prevalent. The results provided evidence to support the validation of the ELISA IDEXX™ as a supplemental test for bTB eradication programs.

Molecular characterization of Mycobacterium bovis infection in cattle and buffalo in Amazon Region, Brazil

Veterinary Medicine & Sci

Pasquatti

Takatani³

et al. 2019

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The aim of this study was to characterize Mycobacterium bovis from cattle and buffalo tissue samples, from two Brazilian states, and to analyse their genetic diversity by spoligotyping. Tissue samples from tuberculosis suspect animals, 57 in Amazonas State (12 cattle and 45 buffaloes) and six from Pará State (5 cattle and one buffalo) from slaughterhouses under State Veterinary Inspection, were isolated in culture medium Stonebrink. The positive cultures were confirmed by PCR and analysed by the spoligotyping technique and the patterns (spoligotypes) were identified and compared at the Mycobacterium bovis Spoligotype Database (http://www.mbovis.org/). There was bacterial growth in 44 (69.8%) of the tissues of the 63 animals, of which PCR for region of differentiation 4 identified 35/44 (79.5%) as Mycobacterium bovis. Six different spoligotypes were identified among the 35 Mycobacterium bovis isolates, of which SB0295, SB1869, SB0121 and SB1800 had already been described in Brazil, and SB0822 and SB1608 had not been described. The most frequent spoligotype in this study (SB0822) had already been described in buffaloes in Colombia, a neighbouring country of Amazonas state. The other identified spoligotypes were also described in other South American countries, such as Argentina and Venezuela, and described in the Brazilian states of Rio Grande do Sul, Santa Catarina, São Paulo, Minas Gerais, Mato Grosso do Sul, Mato Grosso and Goiás, indicating an active movement of Mycobacterium bovis strains within Brazil.