RCG: OpTick: One Health surveillance and management of tick-borne disease threats in a changing environment.

Tick-borne disease (TBD) risks to humans and livestock are increasing rapidly in temperate regions, including the UK, and can cause severe disease in people and livestock, impacting human health and livelihoods. These threats are difficult to manage due to under-reporting, a lack of effective vaccines and are likely to increase as a result of policy-driven changes in the way agricultural land is managed, namely increases in woodland and wildlife habitat and around farms.

These changes will increase habitat for the key tick vector, Ixodes ricinus, which is widely distributed and expanding in UK woodlands and agricultural land, and can transmit important diseases to humans and animals. We urgently need to understand the ecological processes underpinning risk from TBDs - in particular, how landscape conditions, management and climate affect tick populations, livestock and wildlife involved in transmission, now and in the future.

We need to analyse how land, health and livestock management interventions and policies can affect TBD risks and which interventions are most cost-effective and align with farmer priorities and farm practices. Finally, since animals, humans, ticks and environmental management all affect TBD risks, we need to link policy, evidence and interventions across the Animal Health, Human Health and Environment sectors into integrated 'One Health' responses to improve mitigation of current and future TBD threats.

Bringing together researchers from ecology, epidemiology, economics, Public and Animal Health, and social science, OPTICK will address these gaps and provide the evidence base for designing disease management and land management strategies that optimise benefits to livestock production, human health and biodiversity while minimising livestock and human risks from endemic and emerging TBD threats, by:

1. Bringing together key national and regional level stakeholders in land, livestock and tick-borne disease management, to understand their priorities, evidence needs and feasible interventions for TBDs. 2. Generating baseline data on the distribution, economic burden and societal impacts of TBDs in livestock.

3. Better understanding how the agricultural landscape structure and management shapes key interactions between livestock, wildlife, ticks and people that determine TBD risk, combining ecological surveys, pathogen genetics and computer modelling.

4. Integrating data on where ticks and pathogens occur in livestock, humans and people across sectors into new risk maps and models at the UK scale to (i) understand the role of climate, animals and land use change in determining current and future UK foci of tick-borne diseases and (ii) identify gaps in surveillance.

5. Co-creating optimal local vector control and disease management strategies with local stakeholders by understanding the costs and benefits of interventions and how they align with perceptions, practices and priorities of land managers, livestock owners and policy makers.

6. Co-developing surveillance tools, risk guidance and a strong One Health interface between science and research to enhance preparedness for emerging and endemic TBDs

OPTICK will study four priority diseases transmitted by the tick, Ixodes ricinus, which affect sheep and cattle production and human health; Louping ill, tick-borne fever and babesiosis can cause severe illness and death in livestock and Lyme Disease which can cause illness in humans. Farming and veterinary bodies rank these underreported tick-borne diseases of livestock as "high impact, low prevalence, high priority diseases".

Lyme disease is a significant and emerging concern to human health in the UK with reported cases increasing 10-fold since 2000 and can cause long-term debilitation. Our approach of co-developing research, models and risk outputs with stakeholders will ensure that interventions are effective and appropriate and will underpin future integrated One Health responses to TBDs.