An on-going investigation into the ecological determinants of Lyme disease in the South Downs National Park, South East England: the potential for 'One Health' based interventions
Lyme borreliosis (LB) is a tick-borne infectious disease, with UK annual diagnoses trebling over the last two decades. The widening UK distribution of the main LB tick vector (Ixodes ricinus) has been linked to deer population expansion. However, the wider ecological determinants that affect the density of infected ticks are poorly understood. Deer have key roles in most, but not all, UK LB disease systems, but they are non-competent hosts for the pathogen itself, and small mammals or birds are usually obligatory disease reservoirs. In addition, the relapsing fever spirochete Borrelia miyomotoi was detected in the UK in 2014, but the spread and extent of this emerging human pathogen is still unknown. To date, five sites have been drag-sampled across the South Downs National Park (SDNP); with ticks being successfully obtained from all sites. In addition, ticks have been collected from a further sixteen sites where individual or multiple deer were sampled. Currently, ticks are undergoing genetic analysis to determine the host animals involved in the disease cycle, and the presence of Borrelia sp. The study aims to provide a mapped assessment of LB risk across the South Downs National Park, and identify the disease reservoir community composition. The results will help elucidate the causal factors in the SDNP, and support development of policies that avoid or minimise conflicts between public and ecosystem health
