Ticks and zoonotic tick-borne pathogens in Scotland: evaluating risks for humans and livestock

Challenges

Tick populations and tick-borne disease incidence have been increasing in recent times due to changes in climate, land, and behaviours. Globally, ticks are the second most important vector, organisms that transmit infectious pathogens, after mosquitoes. In the UK, ticks transmit tick-borne pathogens (TBPs), such as Lyme disease and the louping-ill virus. Environmental factors influence the risk of TBPs for livestock and humans. However, it is apparent that livestock and humans themselves are instrumental in changing tick and TBPs distribution.

The Covid-19 pandemic highlighted the need for further research into emerging and zoonotic pathogens, especially with alterations in land use and contact with farmed livestock and wildlife. Previous tick-related research has revealed important gaps in knowledge, especially concerning how humans and livestock interact with the environment to impact their own TBD risk. For example, by modifying habitats, management practices, and inducing fear of humans or competition with livestock.

We require more accurate and up-to-date models and risk maps. We have developed early risk maps which have been useful for identifying gaps in data, invalid assumptions, and methodological weaknesses. However, developing new state-of-the-art models and risk maps can overcome the shortfalls of previous models and better estimate tick abundance.

Questions

Solutions

This project adopts a One Health approach focusing on how both humans and livestock interact with the environment to increase their interactions with ticks and TBP risk. Humans and livestock are crucial drivers of tick and pathogen-host distribution and abundance and it may be more viable to focus on them for mitigating disease risk than the wider environment.

We are further understanding how humans and livestock interact with, and change, environmental factors to shape the risk of livestock and human zoonotic TBDs. This involves combining existing and new data to analyse how humans and livestock interact with environmental factors to shape their own exposure to zoonotic vector-borne pathogen risk.

Next, we are developing improved risk maps through spatial modelling. Our models enable us to assess the abundance and risk of ticks, and the zoonotic pathogens they transmit, across Scotland. We have benefitted from previous work which has highlighted shortcomings in predictive risk models, and the need to identify exactly where the strengths and weaknesses lie. Our new risk models are novel, improved and incorporate a wealth of new data. We are also providing additional capabilities for vector-borne pathogen molecular research to analyse further tick samples.