Exploration of the spatial epidemiology of tick borne pathogens of livestock in southern Cumbria

• Main Author: Perrin, L. D.
• Published: University of Salford 2017
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.736446

Changes to farm production subsidies are provoking the maintenance of far less stock. Given that wildlife is more abundant in sustainable uplands, pathogens able to exploit both wild-living and domesticated hosts are of particular concern. Tick-borne pathogens are not only a case in point; but also their threat is now augmented by increasing tick abundance, changing climate, and the extraordinary nationwide increase in the abundance of deer (that serve as a key host species). The major objective of this thesis was to further understand the spatial distribution of questing Ixodes ricinus ticks across farms in Southern Cumbria; as well as to attempt to understand the epidemiological and ecological factors that have a significant influence on the patterns of infections in livestock. This project integrated field work, GIS, molecular methods and citizen science in an effort to understand these complex epidemiologies. Results demonstrated that: <I>I. ricinus</I> exhibit a patchy distribution across all study sites, with proximity to woodland indicated as the main driver behind this. The causal agent of tick borne fever, <I>Anaplasma phagocytophilum</I> was observed across the sites, with sheep being implicated as the main drivers behind this, rather than deer. Conflicting to anecdotal evidence, <I>Babesia divergens</I> (the agent of red water fever in cattle) was not found at any of the sites. However, the discovery of <I>B. venatorum</I> in a new area of the UK is of potential medical importance. In addition to the confirmation of <I>B.</I> OO-2012, and a <I>B. odocoilei</I>- like species; this, to the best of my knowledge, is the first recording of these pathogens in the UK. Contrary to scientific studies, <I>Borrelia afzelli</I> was observed in adult <I>I ricinus</I> females feeding on cattle; suggesting that the results from in vitro assays do not seamlessly translate into the field, and that further work is needed to quantify the role cattle may play in the circulation of Borrelia, which is of public health importance. Louping Ill Virus was sampled for, but was not confirmed. The truly multidisciplinary nature of this project, has demonstrated the need for a holistic approach when considering the ecology and epidemiology of tick borne disease.