Health Explained What is Lyme disease - BBC 24-05-2011
Lyme disease is a bacterial infection transmitted by tick bites. The ticks themselves have to be infected with the bacteria in order to pass it on, and most bites do not result in the condition; but the UK sees around 3,
000 cases a year and the number is on the rise.
Jolyon Medlock runs the
Health Protection Agency's tick surveillance and research project from the
HPA's
Porton Down laboratory. His unit has built up a collection of around 10,000 specimens collected from all over the UK.
They encourage members of the public to send in any ticks they find on themselves or pets after they have been out in the countryside. This information is helping to build up a better picture of the current distribution of ticks and where they may be expanding their range.
Jolyon Medlock explained to
BBC News what Lyme disease is and what symptoms to look out for. He describes how people catch it from ticks, what can be done to prevent getting bitten and how to safely remove a tick.
Ticks that can transmit Lyme disease may be more prevalent in the UK than realised, say researchers who have found out how many dogs harbour them.
Experts have suspected for some time that the UK has a growing problem with these tiny pests - rates of the disease have been creeping up in recent years.
In
2010 there were 953 reported cases in
England and Wales.
Now, after doing random checks on over 3,
500 dogs,
Bristol University experts suspects the problem is even bigger.
Of the 3,
534 pet dogs inspected at veterinary clinics in the UK between March and
October 2009, 14.9% had ticks.
Of the 739 samples that could be tested, 2.3% turned out to be infected.
From this, the researchers calculate that the expected prevalence of infected ticks on dogs is 0.5% or 481 infected ticks per
100,000 dogs.
And they say this suggests that the prevalence of this Borrelia infection in the UK tick population is considerably higher than previously thought, if you assume that the infection rate in dogs is a fair reflection of how many humans are likely to be infected.
Faith Smith, who led the research, told the journal Comparative Immunology, Microbiology and
Infectious Diseases: "Lyme disease appears to be a rapidly growing problem in the UK with important health and economic impacts in terms of loss of working hours and potential decrease in tourism to tick hotspots.
"
Without considerably better surveillance and routine diagnostic testing, Lyme disease is only likely to become more prevalent.
"In particular, future warmer winters might well extend the period over which ticks are active seasonally, while growing wild reservoir host populations, such as deer, will allow the tick population to expand."
Easy to miss
A bite from an infected tick can take between two days and four weeks to show and anyone who has been bitten should look for a "bulls eye" type red rash appearing around the bite.
You may also experience flu-like symptoms, such as tiredness, headaches and muscle or joint pain.
Untreated, Lyme disease can spread to the brain, heart, and joints and in extreme can cause nerve damage, paralysis and blindness.
Ticks are very small - about the size of a poppy seed - and can easily be overlooked.
Most ticks do not carry the infection, but they should be removed promptly if found.
They can be removed with tweezers or special tick hooks, pulling gently upwards away from the skin.
Experts advise against squeezing or twisting the body of the tick, as this may cause the head and body to separate, leaving the head embedded in your skin.
People who develop a rash or other symptoms after a tick bite should consult their GP.
A spokeswoman from the Health Protection Agency said it was important that people realise the risks and remain "tick aware".
"They are out there in woodland areas." She said it was best to keep to footpaths and avoid long grass where possible when out walking and to cover up the skin.
Also, brush off clothes and pet's coats before returning indoors to remove any unattached ticks that might later seek a feed.