Roadmap for development of diagnostic tests for helminths

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

A better understanding of the antibody responses to the various parasite species and antigens at different stages of infection and how this relates to infection intensity, disease and production impacts. This is needed to underpin the development of diagnostics based on the detection of host antibody responses responses.

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

• Incomplete knowledge of immune responses and immunoregulatory responses in hosts to different helminth infections.
• Incomplete understanding of how immune parameters vary during the course of infection (such as antibody isotype switch to inform choice of detection system).
• Incomplete understanding how antibody responses and cellular responses correlate with intensity of infection, pathology, production impacts or host resilience.
• Incomplete information available on dynamics of host responses in relation to stage of infection. e.g. juvenile versus adult infection in fluke, hypobiotic larvae).
• Incomplete understanding of specifity of antibody responses to different species and stages of helminths.
• Lack of reagents to probe antibody responses for target livestock species. Eg. Isotype specific antibodies

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

• More complete descriptions of host immune and immunoregulatory responses to helminth infections in experimentally and naturally infected animals.
• Full characterisation of immunoglobulin isotype responses, to specific parasite antigens, linked back to the type of immune response induced during infection.
• Better understanding of the rate of decay of parasite specific immunoglobulin molecules post-treatment or parasite expulsion.
• Identification of immunogenic stage specific antigens that elicit detectable antibody responses.
• Assess quantitative relationships between antibody responses and infection levels and parasite induced production losses. Determine thresholds for clinical or economically relevant infection levels.
• Study seasonal and yearly (climate driven) infection dynamics and determine optimal timing for sampling, to detect or predict infection levels and/or associated production losses.
• Large scale epidemiological studies to determine between and within-herd spatio-temporal variability in parasite infections and parasite specific host immune responses

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

Better reagents, tools and techniques for investigating the antibody responses of target livestock species.

Existing knowledge including successes and failures