Lyme disease cases in England rise by more than 20% in a year

Cases of Lyme disease have risen more than 20% in England in the past year, public health experts have revealed, as pharmaceutical companies work to create new vaccines and drugs to tackle the tick-borne illness.

According to data from the UK Health Security Agency (UKHSA), published as part of its One Health vector-borne disease surveillance report, there were 1,168 laboratory-confirmed cases of Lyme disease in 2025, up from 959 in 2024 – an increase of 22%. However, the figure is similar to that recorded in 2023, when there were 1,151 confirmed cases.

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 identified in the UK.

Dr Claire Gordon, the head of the rare and imported pathogens laboratory at UKHSA, said: “While the number of laboratory-confirmed acute cases of Lyme disease in 2025 is an increase on numbers reported in 2024, we expect overall case rates to vary year to year depending on awareness, testing rates and factors that impact outdoor activities such as weather. Broader trends in 2025 remain consistent.”

Lyme disease is caused by a type of bacteria called Borrelia burgdorferi, which lives in the gut of ticks – tiny spider-like creatures found in grassy and wooded areas that feed on the blood of birds and mammals, including humans.

“In recent years, we have seen an increasing geographical distribution of ticks across the UK,” Gordon said. “But tick numbers continue to vary due to changes in weather conditions, climate trends, habitat changes and shifting host populations.”

Symptoms of Lyme can include a bullseye-like rash, fever, muscle and joint pain, and lethargy. Left untreated, the condition can become chronic and, even among those who receive antibiotics, some report ongoing symptoms.

Not all ticks carry Lyme bacteria, and it is thought rapid removal of ticks reduces the risk of infection after a bite. But while there are various medications available to protect pets from Lyme disease – including monthly oral tablets and vaccinations – advice for humans centres on prevention, such as using repellants, covering exposed skin outdoors and wearing light-coloured clothing to make ticks easier to spot.

Linden Hu, a professor of immunology at Tufts medical school, said there were a number of reasons veterinary and human approaches differed, noting that pet owners were often more willing to medicate their dogs than themselves or family members, while clinical trials in humans were harder to conduct.

“It’s easier to do studies in animals because you can control the situation. You can put infected ticks on them to test if it’s going to work, which you really can’t do with humans,” he said, adding real-world studies, or “field trials”, were expensive and risky, given that it was unclear how many cases of Lyme would occur.