Roadmap for the development of control strategies for liver fluke

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

• Can we set up a monitoring system to detect changes over time and act as decision support tool on European level?
• Need to develop standardised surveillance systems.

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

• Lack of harmonisation of diagnostic systems.
• Needs country or even continental-based approach.
• More effective use of abattoir data and systems to trace animals’ movement history to identify source farms and where infection occurred.
• Set up network of sentinel farm also for other infections.
• Need to assess minimal required sample size.
• Impact is actually related to level of infection and not just prevalence so need to determine the extent to which prevalence, or prevalence-above-threshold, can be a useful synoptic measure to characterise baseline infection and detect changes.

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

Use of existing sample collection schemes based on bulk tank milk monitoring programmes and veterinary and hunting networks for the collection of faecal samples from non-dairy livestock and wildlife. Collection and collation of abattoir data.

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

• Harmonize or integrate diagnostic and data collection systems across various countries and regions.
• Assess cost-benefits of such an approach and develop how this can be effectively communicated.

Existing knowledge including successes and failures

Complementary to predictive systems, it is important to set up surveillance systems that monitor infection status at farm level on a regular basis. Such systems can capture unexpected deviations from mathematical model predictions and indicate whether farmer management is able to cope with altered disease risk or not. Recently, it was shown that monitoring F. hepatica‐ specific antibody levels in bulk tank milk from a randomized sample of dairy farms allowed detection of both interannual (weather‐driven) changes as well as longer‐term trends in F. hepatica exposure. Moreover longitudinal monitoring approaches have also been shown to be an effective decision support tool.