Roadmap for development of disease control strategies for bTB

What are we trying to achieve and why? What is the problem we are trying to solve?

• Due to limited test sensitivity and pathogenesis, a proportion of infected animals fail to react to current tests; can we quantify this, and what are the implications of the undiagnosed cases?
• Excretion levels – when do animals become infectious?.
• To develop biosignatures (combination of biomarkers) that could inform on the latent/carrier status of an animal and evaluate the risk of Mb shedding and transmission .
• Development of tools to identify animals at risk to transmit for targeted elimination to end massive herd culling

What are the scientific and technological challenges (knowledge gaps needing to be addressed)?

• Challenging to distinguish exposure from infection and infectivity.
• Immunoreactivity indexes past exposure.
• No validated live test to confirm infection in cases testing negative.
• Whether M. bovis establishes long-term infection and reactivation remains to be demonstrated/quantified.
• We need to understand the different clinical states of TB in cattle akin to what is now establish for human TB
• We need to develop easy and affordable tools to identify biosignatures
• We need to identify a biosignature in circulating blood (the easiest and less invasive procedures for sampling large numbers of animals)

What approaches could/should be taken to address the research question?

• Epidemiological analysis of herds with confirmed TB cases, unconfirmed immunoreactive cases and cases found lesioned at slaughter; investigate secondary attack rate etc.
• Molecular epidemiology data suggestive of long-term undisclosed infection in cohort of moved animals.
• Monitor excretion levels in different infection situations, Embrace the One Health approach and work together with human TB specialists

What else needs to be done before we can solve this need?

• Comprehensive cattle identification, registration, movement, and test data.
• We need to establish robust pipelines with all stakeholders including bTB surveillance programs- to ensure rigorous and longitudinal follow-up of animals in the field

Existing knowledge including successes and failures