What is Lyme disease?

Lyme disease is an infection with a bacterium (germ) called Borrelia. There are various subtypes of Borrelia bacteria but Borrelia burgdorferi causes most cases of Lyme disease. The bacterium exists in animals such as deer and mice and is passed to humans via ticks feeding off the infected animals. It is called Lyme disease because in 1975 in a town called Old Lyme in the USA there was an outbreak of arthritis in young children which was found to be due to this infection. This was the first time that this bacterium was recognised to be the cause of a medical condition. That said, there is evidence of the bacterium in Victorian Britain so it has probably been around for a very long time.

How do humans get Lyme disease?

The bacterium that causes Lyme disease lives in certain animals such as deer and mice. The bacterium is usually harmless to the animals themselves. When ticks feed off these animals they then are able to carry the infection to a new host, including humans. The ticks themselves are small insect-like creatures about the size of a pin head and reddish brown in colour and thus, they are difficult to spot. The bacterium that causes Lyme disease is not passed from person to person.

It normally takes 24 to 48 hours for bacteria in the tick to pass into the human after being bitten. Ticks are tiny and 'cling on' to you once they bite you and this 'clinging' means they will typically resist being washed off. They then suck blood and 'engorge' with blood which they feed off. The bacteria are normally carried in their gut, and only travel up to their mouth and into your skin once they have been feeding for more than 24 hours and are engorged. Therefore, if you remove a tick soon after being bitten - within 24 hours - you are very unlikely to develop Lyme disease, even if it was an infected tick.

So it is only infected ticks that carry Lyme and they have to be in place quite a while. However ticks are tiny and because they inject their own 'anaesthetic' into the wound they mostly do not hurt when they bite. It is quite easy to have a tick bite without you noticing for example, on your leg or back. Many people who develop Lyme disease cannot remember being bitten by a tick and this is certainly true in my case.

What precautions should you take?

Remember that Lyme disease in the UK is not common although the incidents are increasing. In some cases even if you don't know you have been bitten and you are unlucky enough to have been bitten by an infected tick, you will develop a tell-tale 'bullseye' rash. Your GP will probably recognise this and treat you with anti-biotics which will almost certainly end the problem, although he should ensure the dose is of sufficient strength.

In many cases (mine included) there is no rash. If you start to feel constantly nauseous, have difficulties with your heart and/or presistent 'flu like' symptoms you should seek medical advice. I never had these symptoms but did have severe headaches, neck pain and fatigue. I also began to develop difficulties with walking and balance which deteriorated significantly, so you should be aware that this disease can manifest itself in different forms.

The best form of defence against the disease is to ensure you wear long trousers and sleeves when in potentiallly infected areas (forests and such like) and to tuck trousers into boots. Using an insect repellent on exposed skin is also worthwhile. Prevention is definitely better than cure!

 Lyme Disease in Britain               Ticks in Britain