A potentially deadly virus carried by ticks is now present in the UK, health officials have warned.
The UK Health Security Agency (UKHSA) and Defra said that the first domestically acquired case of tick-borne encephalitis (TBEV) was confirmed in a 50-year-old man in Yorkshire.
The virus, which is already common in many parts of Europe, is an important cause of viral infections in the central nervous system.
It can cause a range of illnesses from completely asymptomatic infection to mild flu-like illness, right through to severe infections of the central nervous system such as meningitis or encephalitis.
The UKHSA and Defra stressed that the risk to the public is low, but warned hikers and mountain bikers to protect themselves from tick bites.
There have been three cases of probable or confirmed TBEV in England since 2019, with the first confirmed case in Yorkshire in 2022, and a probable case detected in the Loch Earn area of Scotland in the same year.
The virus has also been detected in the Hampshire, Dorset and Norfolk areas, but health officials warned that it may also be present elsewhere as the tick species which carries the virus is widespread in the UK.
Ticks can carry other diseases such as Lyme disease – a bacterial infection which can be treated with antibiotics.
Dr Meera Chand, Deputy Director at the UK Health Security Agency, said: “Our surveillance suggests that tick-borne encephalitis virus is very uncommon in the UK and that the risk to the general population is very low.
“Ticks also carry various other infections, including Lyme disease, so take steps to reduce your chances of being bitten when outdoors in areas where ticks thrive, such as moorlands and woodlands, and remember to check for ticks and remove them promptly.”
The UKHSA has recommended changes to testing in hospital so that further cases can be detected promptly.
Ian Jones, a professor of virology at the University of Reading, said: “It is unlikely that TBEV will disappear, but the general threat level is very low and there is no reason to suppose cases in people will be any more than sporadic in nature.
“A vaccine is used in areas of high incidence in Europe and could be considered here for individuals with outdoor occupations in areas where the virus is found. For the general public, however, the risk is minimal.”
Roman Biek, professor of disease ecology and molecular epidemiology at the University of Glasgow, said the disease was “more widely distributed in the UK than we had anticipated”.
He said the “most plausible” cause of the spread was an increased number of infected ticks travelling on migrating birds.
“Luckily, the chances of becoming infected are low and the same measures that are recommended to protect yourself from tick bites in general, will also be the first line of defence against this virus.
“This means being ‘tick-aware’ and includes covering your legs and ankles, using insect repellent, and checking yourself and your clothes after spending time outdoors.”
