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?

• Prevention of disease transmission through improved biosecurity measures.
• Prevent introduction of TB into a herd, within-herd amplification and onward transmission to other herds and possibly local wildlife, establishing a local cycle of spillover/spillback.
• Accepting that infectious local wildlife represent a well documented risk, limit potential for introduction by adopting biosecurity measures to minimise exposure.
• Accepting that other cattle, including those testing false negative, pose a risk, take reasonable precautions to limit exposure to that potential source.

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

• Identifying cost-effective tools and strategies to improve on farm biosecurity.
• Challenging to communicate and “prove” that “common sense” biosecurity measures, such as informed purchase, risk-based trading, wildlife exclusion etc. will reduce risk on a specific farm.
• Contextualize and adapt standard biosecurity measures in local settings? Needs likely to be context-dependent and likely to require veterinary input.
• Some evidence of misinformation and confirmation bias in stakeholder spectrum.
• Education of small-holder farmers (e.g., training on better practices to be used). Consider herd certification or accreditation schemes, if available.
• Consider herd-level veterinary risk and management plan approach (VRAMP).
• Aging and variable cattle housing systems.
• Getting producer and worker engagement to do biosecurity every day.
• Showing that there is value in everyday biosecurity.
• Biosecurity likely equally relevant to other infectious diseases that transmit on the network of cattle farms, i.e., BVD, Johne’s, IBR etc.
• Evidence that biosecurity measures can limit the direct/indirect exposure of cattle to wildlife; lacking published evidence that such measures associated with reduced risk.

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

• Establish the effectiveness of a) strict testing and quarantine procedures when animals are introduced into a herd, b) separation of livestock from wildlife – zero grazing, c) control of wildlife reservoirs.
• Recognised difficulty in “proving” that biosecurity measures work.
• Consider herd certification or accreditation schemes, if available.
• Consider adopting and evaluating herd-level veterinary risk and management plan approach (VRAMP).
• Might be possible to associate enhanced biosecurity measures with reduced incidence if sufficiently powered, controlled and replicated case-control risk factor epidemiological studies can be undertaken.

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

• Knowledge of the locally relevant sources of infection and transmission pathways; for example, a small number of published, context-dependent, transmission dynamics studies illustrate the importance of within-herd cattle-cattle spread amplifying the initial introduction of TB.
• Establishing the local importance of wildlife reservoirs should inform intervention decisions.
• Establishing the survival of the pathogen in the local farmed environment and farm slurry/silage, digestate etc.
• Establish the importance of disinfection procedures.

Existing knowledge including successes and failures

Published evidence suggests that the risk from slurry appears relatively low.