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?

How does infection with liver fluke affect the course of infections with other pathogens and vice versa? What are the implications for fluke control?

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

Fluke infection appears to have effects on infection with and detection of several other pathogens. Deeper understanding is needed before implications are clear.

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

Intervention studies that introduce or eliminate liver fluke from animals and document the consequences for establishment and detection of bacterial and viral infections, and effectiveness of vaccination against them.
Characterisation of host immune responses to fluke alone and combined infections; effects of attempts to manipulate these interactions, e.g. through controlled exposure or immunomodulation.

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

• Ability to run controlled infections including with regulated pathogens.
• Better immunological tools to study ruminant immune responses.

Existing knowledge including successes and failures

Relationships have been observed between fluke infection and several microparasites, which affect infection status and outcomes, including increased susceptibility to bacterial infections (Clostridium, Samonella and E. coli O157) in fluke-infected animals, and impaired immune responses to bacteria and consequent low detection sensitivity (bovine tuberculosis). It is possible that these are widespread and affect control, e.g. through the efficacy of vaccination, and by inhibiting surveillance schemes. However, these implications have not been thoroughly
explored to date. Interactions between liver and rumen flukes in the definitive or intermediate hosts might affect disease outcomes and epidemiology but have been little explored to date.