Date: Tue 29 Oct 2019
Source: BBC [edited]
An infectious disease that can harm the brain and is spread to people by tick bites has been identified in ticks in the UK for the 1st time. Public Health England (PHE) says it has confirmed cases of tickborne encephalitis virus in ticks from 2 parts of England -- Thetford Forest and an area on the Hampshire-Dorset border. PHE says the risk to people is still "very low". It is monitoring the situation to check how common the infected ticks may be.
A tick is a tiny, spider-like creature that lives in undergrowth and on animals, including deer and dogs. People who spend time walking in countryside areas where infected ticks can be found are at risk of being bitten and catching diseases they carry. Tickborne encephalitis virus is already circulating in mainland Europe and Scandinavia, as well as Asia. Evidence now shows it has reached the UK.
How it got here is less clear. Experts say infected ticks may have hitched a ride on migratory birds. Earlier this year , a European visitor, who has since recovered, became ill after being bitten by a tick while in the New Forest area, Public Health England says. Further investigations revealed infected ticks were present in 2 locations in England.
Ticks are becoming commoner across many parts of the UK, largely due to increasing deer numbers. Being bitten by one doesn't necessarily mean you will get sick. Dr Nick Phin, from Public Health England, said: ''These are early research findings and indicate the need for further work. However, the risk to the general public is currently assessed to be very low."
Most people who catch the virus will have no symptoms or only mild flu-like symptoms. But the disease can progress to affect the brain and central nervous system and can sometimes be fatal. Ticks can also carry other diseases that can make people ill including Lyme disease. Dr Phin said: "We are reminding people to be 'tick aware' and take tick precautions, particularly when visiting or working in areas with long grass such as woodlands, moorlands and parks."
What should I do?
- To reduce the risk of being bitten, cover your skin, tuck your trousers into your socks, use insect repellent and stick to paths
- If you are bitten, remove the tick with fine-tipped tweezers or a tick-removal tool found in chemists
- Clean the bite with antiseptic or soap and water
- You should go to your GP if you think you may have been bitten by a tick in the past month and develop flu-like symptoms or a circular red rash
Ticks feed on the blood of animals and people. They cannot jump or fly but live in vegetation and wait for a passing animal or human to climb on to. [byline: Michelle Roberts]
[Although tickborne encephalitis (TBE) virus has not been detected in the British Isles before, there is another related established flavivirus, louping ill, transmitted by _Ixodes ricinus_. The above report does not indicate in which tick species TBE virus was found, perhaps it was _Ixodes ricinus_ as well. The rodent host of the virus was not mentioned either. In mainland Europe where TBE is endemic, the bank vole (_Myodes glareeolus_) is the rodent host of the virus. That rodent is found throughout the British Isles and it would be interesting to know if TBE virus is present in that rodent population.
It is not surprising that TBE virus has found its way to the United Kingdom. A report in Eurosurveillance Weekly in 2004 stated, "Tickborne encephalitis (TBE) is endemic in virtually all countries in Central and Eastern Europe. It is caused by several closely related but distinct flaviviruses. A total of 3 subtypes are recognised at present: a Far-Eastern subtype, a Siberian subtype and a European subtype. The Siberian subtype is associated with Russian spring-summer encephalitis and is transmitted predominantly by the tick _Ixodes persulcatus_, whereas the European subtype causes central European encephalitis and is transmitted by _Ixodes ricinus_.
The clinical spectrum of acute TBE ranges from symptoms of mild meningitis to severe meningoencephalitis with or without myelitis. The incubation period of central European TBE is 7-14 days. Onset is generally biphasic. The 1st phase involves a non-specific influenza-like illness with fever, headache, nausea, and vomiting, lasting about a week. After a period of remission lasting a few days, the fever returns with aseptic meningitis or encephalomyelitis. The case fatality rate is 1-5%and about 20% of survivors have neurological sequelae. Residual motor defects are rare." - ProMED Mod.TY]
[Also see Public Health England's press release:
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