Cases of Lyme disease have risen by more than 20% in England in the past year, according to data from the UK Health Security Agency (UKHSA). There were 1,168 laboratory-confirmed cases in 2025, up from 959 in 2024, an increase of 22%. However, the figure is similar to the 1,151 cases recorded in 2023.
Two probable cases of tick-borne encephalitis complex were also identified in 2025, bringing the total number of locally acquired cases to six since 2019, when the virus was first detected in the UK. Dr Claire Gordon, head of the rare and imported pathogens laboratory at UKHSA, said the increase in Lyme cases was expected to vary year to year depending on awareness, testing rates and outdoor activities.
Lyme disease is caused by the bacterium Borrelia burgdorferi, which lives in the gut of ticks found in grassy and wooded areas. Symptoms include a bullseye-like rash, fever, muscle and joint pain, and lethargy. Left untreated, it can become chronic. Not all ticks carry the bacteria, and rapid removal reduces infection risk.
Pharmaceutical companies are developing new vaccines and treatments. An mRNA vaccine from Moderna is in phase 2 clinical trials, while a vaccine from Pfizer and Valneva is to be submitted to regulators after showing over 70% efficacy in a phase 3 trial. Other approaches include a monoclonal antibody from Tonix Pharmaceuticals.
