A ticking time bomb
|Author: Clara Lawrie||Published: 27th March 2012 08:03|
Wendy Fox is the Chairperson and a founder member of BADA-UK, a registered charity that aims to raise awareness about tick-borne diseases in the UK. Her background is in zoology.
Wendy was left paralysed and severely visually impaired after Borreliosis caused swelling in her brain and spinal cord.
To minimise the risk of being bitten by an infected tick Dr Sue O'Connell advises people to:
- Wear appropriate clothing in tick-infested areas (long sleeved shirt and long trousers tucked into socks). Light coloured fabrics are useful, as it is easier to see ticks against a light background
- Check that ticks are not brought home on clothes.
- Consider using insect repellents, e.g. DEET-containing preparations.
- Inspect skin frequently and remove any attached ticks.
- At the end of the day, check again for ticks, especially in skin folds.
- Make sure that children's head and neck areas, including scalps, are properly checked.
- Check that pets do not bring unfed ticks into the home on their fur.
With warmer winters allowing more ticks to survive, and to feed and breed earlier, cases of UK-acquired tick-borne disease are increasing quite dramatically. In addition, urban-acquired cases are becoming more frequent
During the last few years, tick-borne diseases have been highlighted as something of an increasing concern in the United Kingdom.
A rise in tick numbers
Changes in land management and the climate are just some of the factors contributing to a rise in the tick population. With warmer winters allowing more ticks to survive, and to feed and breed earlier, cases of UK-acquired tick-borne disease are increasing quite dramatically. In addition, urban-acquired cases are becoming more frequent as urban sprawl blurs the boundaries with rural habitat, and urban wildlife becomes established.
Probably the most recognised tick-borne disease in the UK is 'Lyme disease'. It is just one of several diseases present in the UK. Lyme disease gets its name after a cluster of cases that were discovered in Old Lyme, Connecticut, in the US. It is caused by a spirochaetal bacterium called 'Borrelia burgdorferi' but there are hundreds of differing strains and sub-types which result in varying symptoms. These can range from more dermatological and rheumatological symptoms, to more serious neurological manifestations.
Borreliosis (as the disease is more correctly termed to cover the differing strains) can be extremely debilitating. European strains generally have more neurological complications, presenting as 'viral-like' meningitis, encephalopathy, facial palsy, peripheral neuropathy and other nerve inflammation. This can lead to pain, altered or loss of sensation, and loss of co-ordination. In severe cases paralysis may occur.
Often a target-shaped expanding rash (called an 'Erythema Migrans' or' EM rash') is associated with Lyme disease. However, different strains can produce rash variations, and some patients never present with one. Rashes can also be hidden under hair, or in inaccessible places. This can make diagnosis difficult because the only indication of infection may be flu-like malaise. An EM rash can also resemble other dermatological conditions, such as ringworm, cellulites or an allergic reaction, and misdiagnosis can occur as a result.
Borrelia bacteria are related to the syphilis spirochaete but are more complex. They are pleomorphic (meaning they can change their physical form). This aids them to evade the body's immune system and can make indirect methods of detection (such as serologic testing) difficult.
A cocktail of infection
In addition to Borreliosis, ticks can carry a cocktail of bacterial, viral, rickettsial and protozoal diseases concurrently. Anaplasmosis (a rickettsial disease) is the most common co-infection. Multiple infections can complicate both diagnosis and treatment.
A threat to travellers abroad
Tick-borne diseases occur worldwide but, for the European traveller, Tick-borne encephalitis (TBE) is probably the greatest concern. This Flavivirus has spread from central to north-west Europe. It is closely related to Russian spring-summer encephalitis (RSSE) and Louping-ill (which is generally recognised as a disease of sheep in the UK but can affect other animals and people). TBE can cause serious inflammation of the brain and spinal cord which, in some cases, can be fatal.
As of mid 2006, no TBE cases have been reported to the UK's Health Protection Agency (HPA), although it is possible that some cases have occurred but not been reported or recognised.
The TBE group of viruses are the only tick-borne diseases for which there are vaccines. The vaccines are available from GP surgeries, health centres and MASTA clinics. As there are currently no vaccines against other types of tick-borne disease, the only defence against infection is knowledge about ticks and how to remove them.
What ticks look like
a deer tick
Ticks vary in shape, colour and size, depending on the species, sex, age, and whether they have fed. They belong to the spider family and have eight legs (except for when they are newly hatched and have six). There are hard and soft ticks; unfed hard ticks are flat with a hard shield on their backs. Soft ticks have a leathery back which covers their heads.
a soft tick
Ticks are generally flat and black, brown or red-brown coloured, until they have fed. Then they become more blue-grey, purple or fleshy pink. They have several life stages: larva, nymph, and adult. They need a blood meal to complete each phase. Larvae are like tiny dots (approximately 0.5mm). Nymphs are slightly bigger (like a poppy seed), and adults are bigger still, like a sesame seed (2.5-3mm). Once fed, they can swell to the size of a small coffee bean.
Tick bites are generally painless. Their saliva contains special bio-chemicals which have anaesthetic, anti-inflammatory and anti-coagulant properties. Infective organisms are contained within the intestines and saliva glands of the tick and are transmitted during the feeding process. The longer the tick remains attached, the higher the risk of disease transmission.
Where ticks are found
Although associated with rural woodland, forest, moorland and meadow, ticks can be found in lots of places, depending on the species and surrounding wildlife. The areas generally associated with tick-borne disease are the New Forest, Exmoor, the Lake District, the Scottish Highlands and Islands, the North York moors, Thetford Forest, and the South Downs.
However, ticks will occur wherever there is good vegetation cover and diverse wildlife. This can include city parks and gardens. Wherever there are ticks, a proportion will be carrying tick-borne infections.
Ticks that bite people are generally found waiting on low vegetation. They sense a potential host via airborne-chemical particles from the host's breath and skin. They fall on, or latch on to, the host as it passes.
- Wear long trousers and tuck them into socks, or use gaiters. Elasticated waistband and cuffs will help to deter ticks from crawling under clothing. Smooth and waxed materials make it difficult for ticks to climb and light-coloured clothing makes them easier to see.
- Use a repellent; 25-50% 'DEET'-based repellents are effective.
- Where possible, use established paths and walk in the centre to avoid overhanging vegetation.
Remove ticks safely
Injuring or stressing attached ticks can result in them regurgitating their blood meal, which may contain infective organisms. Do not freeze or burn them, or cover them with substances like oils, spirits, nail polish, or petroleum jelly. Do not scratch them off or squash them because this can leave parts imbedded in the skin and spread infective fluids.
Do not use your fingers to remove them as some infective agents can enter through breaks in the skin or through mucous membranes (touching eyes, nostrils or mouth).
Always use a tick removal tool or fine-pointed tweezers.
Ideally, wear plastic gloves when removing ticks.
There are various tick-removal devices on the market but some are not as safe as they claim to be and are likely to cause damage or compression to the tick. In a comparison study of various tick-removal tools, published in the Veterinary Record (2006, 159, 526-529), the O'Tom hook (or Tick Twister) proved to be significantly better than the other devices for the time required to remove the tick, the ease with which the tick was grabbed, the force needed to extract the tick and the condition of the tick's mouth parts.
If using tweezers, approach the tick from the side (to avoid compressing the tick's body) and grasp it as close to the skin as possible. Gently pull / lever upwards. Do not twist as tweezers excerpt too much pressure to the tick's mouth parts and they can break off.
After tick removal
Once the tick has been extracted, the bite site should be examined closely for any remaining parts. If any do remain, they can be removed with a sterilised needle. Then the bite site should be cleaned with antiseptic and hands should be washed thoroughly or disinfected.
It is a good idea to keep the tick as it can help a doctor in making an accurate diagnosis. Write the date of the bite in pencil on a bit of paper and put it with the tick in a plastic bag. Store the bag in the freezer for a number of weeks, as symptoms can take a while to manifest.
Symptoms of infection
If a rash or a reaction around the bite area develops, seek medical advice. Photograph the rash, as this can help during medical consultations at a later date if the rash has faded or resolved.
If changes in your health, such as flu-like symptoms, excessive fatigue, persistent headache (with or without a stiff neck), develop, see a doctor as soon as possible.
- Carry a tick remover and antiseptic wipes.
- Check yourself regularly.
- For comprehensive information, please visit www.bada-uk.org (the registered charity, Borreliosis & Associated Diseases Awareness-UK)