The disease is transmitted to humans by tick bites and if untreated can cause serious disease including meningitis, facial palsy, nerve damage and arthritis.
Scientists at the University of Brighton are coming to the end of a comprehensive study which will map where the ticks and bacteria that cause Lyme disease are distributed across the national park.
Dr Anja Rott, from the university’s College of Life, Health and Physical Sciences, said: “The South Downs National Park has been highlighted as including two of the ten areas in England and Wales where infection with Lyme disease is most frequent. However, no survey of the hazard or the factors affecting it has been carried out across the park.