Bovine Tuberculosis: A Review of Current and Emerging Diagnostic Techniques in View of their Relevance for Disease Control and Eradication

Abstract

Summary Existing strategies for long‐term bovine tuberculosis (bTB) control/eradication campaigns are being reconsidered in many countries because of the development of new testing technologies, increased global trade, continued struggle with wildlife reservoirs of bTB, redistribution of international trading partners/agreements, and emerging financial and animal welfare constraints on herd depopulation. Changes under consideration or newly implemented include additional control measures to limit risks with imported animals, enhanced programs to mitigate wildlife reservoir risks, re‐evaluation of options to manage bTB‐affected herds/regions, modernization of regulatory framework(s) to re‐focus control efforts, and consideration of emerging testing technologies (i.e. improved or new tests) for use in bTB control/eradication programs. Traditional slaughter surveillance and test/removal strategies will likely be augmented by incorporation of new technologies and more targeted control efforts. The present review provides an overview of current and emerging bTB testing strategies/tools and a vision for incorporation of emerging technologies into the current control/eradication programs.

Ocorrência e caracterização da tuberculose em caprinos leiteiros criados no estado de Pernambuco

“…Reações falso-negativas ao TCC em bovinos, anteriormente positivas, podem ocorrer em situações especiais, como em estágios avançados da tuberculose, estresse associado ao parto ou transporte, infecção intercorrente, desnutrição e exaustão ϐísica (Kleeberg 1960, Brasil 2006, Schiller et al 2010. Nesses casos, os achados clínicos e/ ou exames complementares, como a dosagem de interferon gama, PCR e ensaio imunoenzimático, a exemplo do que se observa na espécie bovina, surgem como alternativas no auxilio ao diagnóstico da tuberculose caprina, porém, sendo necessária a padronização de tais técnicas para a espécie (Rothel et al 1990, Collins et al 1994, Brasil 2006, Lilenbaum & Fonseca 2006.…”

Bovine Tuberculosis in the Republic of Macedonia: Postmortem, Microbiological and Molecular Study in Slaughtered Reactor Cattle

“…The slaughterhouse surveillance is not performed successively to the slaughter of the reactors (17) which represents a considerable gap in the disease eradication. Slaughterhouse surveillance represents an important component in bTB diagnosis by detection of tuberculous lesions especially in commercial slaughtering and in animals not reacting in tuberculin tests in both Officially Tuberculosis Free countries (somewhere acting as the only bTB diagnostic tool) and nonOTF countries (17,18).…”

Immunity and Vaccination against Tuberculosis in Cattle

“…Serological responses to mycobacterial antigens have not been linked with protection post-vaccination as shown when TB protein vaccines were used alone, whereas when TB protein vaccines are used concurrently with a BCG vaccine, protection was not adversely affected by the induction of an antibody response [45]. There have been numerous attempts to detect M. bovis infection in cattle using serology, and generally, test sensitivity has been low compared to that for cellular immune responses, although there may be a link between severity of disease and induction of an antibody response [75].…”

“…However, it is still necessary to challenge animals to determine vaccine efficacy and disease. IFN-γ responses by T cells are strongly induced following infection and are often measured as an indicator of disease [75]; however, this parameter is less certain as a correlate of vaccine efficacy. Early IFN-γ responses are required post-vaccination, so the timing of testing is important and the amount of IFN-γ does not always correlate with protection [57].…”