WRITTEN by ANNE ENSOLL
Ticks have been recognised for their ability to transmit disease for hundreds of years. They are currently considered to be second only to mosquitoes as vectors of human and animal infectious diseases worldwide. They are blood-sucking parasitic arachnids, which means that they belong to the spider family. So what should we know about them and the effect they might have on us?
There are three types of tick commonly found in the UK: Ixodes ricinus (the sheep or deer tick), Ixodes hexagonus (the hedgehog tick), and Ixodes canisuga (the British dog or fox tick). The most common is Ixodes ricinus, and its numbers are increasing. The main infection it carries, Lyme disease, is increasing too, with one study finding that in Scotland Lyme disease has increased eightfold in ten years.
I recently had a very informative chat with our vet about ticks. The vet practice has teamed up with Salford University in a study to investigate how many ticks carry Lyme disease. Every time one of the vets removed a tick from an animal, they would send it off to Salford, and along with other ticks collected by the researchers, it would be analysed. The study found that 11% of ticks were carrying the disease. That seemed like a high number to me, so I asked if that was an increase, and the vet said that they didn’t know, because no-one had done this kind of study before.
Where do ticks live?
There are several geographical locations in the UK identified as tick hot-spots, including upland Scotland and Cumbria. However, ticks can occur anywhere with the right habitat - heather, bracken, grassland and woodland are all prime habitat for ticks. Tick nymphs (the second stage of development) need very high humidity to survive so they gather in leaf piles or in long grass in shady, humid environments.
The life cycle of the tick
Ticks can live for up to three years and they feed on the blood of a single host in each of their life stages – larva, nymph and adult.
Ticks hang on to grasses, bracken and other dense vegetation waiting for an unsuspecting host to brush past. Before they have fed on the blood of their host, they are so tiny they can be mistaken for a speck of dirt or a dark-coloured seed.
The saliva of a tick contains anaesthetic, so you’re very unlikely to know that you’ve been bitten. Other chemicals in the saliva stops human blood from clotting while the tick feeds.
A tick remains attached to the host for around five days while feeding. As they feed, adult ticks become lighter in colour and they grow to the size of a raisin. If the host is infected, then the tick will transfer the bacteria in its saliva to a later host.
Some species of tick, including Ixodes, mate whilst the adult female is attached to the host. You will occasionally see an engorged female with a much smaller tick attached to her underside – this is the male.
What infections do they carry?
The most common tick-borne infection in the UK is Lyme disease. Because many doctors are not familiar with the symptoms, which in some cases are mild, infections can go undetected for long periods.
Symptoms of Lyme Disease can take between three days to six weeks to appear after a tick bite. The most obvious sign is a red rash in a ring around the site of the bite. Other symptoms can include headaches, a stiff neck, extreme fatigue, muscle and joint pain, and problems with sight, hearing, digestive system and sleep. If left untreated Lyme disease can be serious - it can progress to the heart and the nervous system.
Survival expert Ray Mears was bitten by a tick and for 16 years battled with the debilitating symptoms of the disease before being diagnosed. He advises people to check themselves over after going for a walk because ticks can now occur anywhere.
How to avoid being bitten by a tick
Use a chemical repellent that is effective against ticks. Make sure you don’t leave any gaps, as a tick could scurry across treated skin and get to places that haven’t been treated.
Wear light-colored clothing to make it easier to see the ticks.
Tuck trouser legs into socks to prevent them crawling up your socks on to bare skin.
Avoid areas known to have high tick populations.
Check yourself, your children, and your pets daily and carefully remove any ticks.
What to do if bitten by a tick
The sooner you remove a tick the better, as it takes time for infections to reach a person's blood stream, especially Lyme disease. There are all sorts of folk remedies for detaching them, from smothering with toothpaste to burning with a cigarette. Whatever method you choose, the key thing is not to leave the mouthparts in your flesh as infection is spread through the tick's saliva. We’ve found the most effective way is to use little tool called a tick twister, which we bought to remove ticks from our dogs.
After removal apply antiseptic and look out for the tell-tale rash.
If you’ve been bitten by a tick and have any of the symptoms, see a doctor. Early treatment with antibiotics is essential for effectively seeing off Lyme disease.