Run for your life!

Trail running, Tick bites and Lyme disease – an overview by Charles Walker, Personal Trainer and GP.

Over the last five years I have become increasingly keen on trail running, and this is reflected in the enthusiasm with which I promote this facet of fitness training to participants attending Bootcamp Ascot sessions.  The combination of exercising outdoors, uneven terrain, hills, natural obstacles and unpredictable conditions – all promote the maintenance and improvement in joint position sense (proprioception) in order to reduce the risk of falls and injury in sport and everyday life.  This all adds to the cardiovascular benefits of running, and builds upon the balance, strength, power and endurance targeted in our eight bootcamp sessions weekly in Ascot and Bracknell.

In May 2012, I noticed a ‘bull’s eye’ spreading rash (the hallmark of Lyme disease) on a runner’s thigh, two weeks after receiving a tick bite during a 10k trail run in Bagshot, Surrey.  The initial bite and surrounding redness, thought to be from an ‘insect’, progressed to the typical rash of erythema migrans over the following ten days.  In 22 years in general medical practice, this was only the third case I had seen, and the first contracted in England.

The aim of this article is to heighten awareness of ticks, their bites and Lyme disease, in order to avoid infection or to receive early treatment if contracted, as this offers the best chance of complete cure.

Most ticks in the UK are not infected with the bacteria that cause Lyme disease, Borrelia burgdorferi.  The bacteria live in certain animals, mainly rodents such as mice, and some birds, and are usually harmless to them.  The disease is named after a town called Old Lyme, Connecticut in the USA where the 1975 outbreak of arthritis in young children, was found to be due to this infection.

 

Erythema migrans Erythema migrans.

In 2011, there were 972 cases of Lyme disease confirmed in England and Wales. However, the total number of cases each year is unknown, because many cases are not formally diagnosed and clear away without treatment. Most people affected are forestry workers/other outdoor workers. However, anyone visiting countryside where ticks are found are at risk, including trail runners, walkers, campers, off-road bikers and horse-riders etc.  With the advent of increasing countryside leisure pursuits, it is wise to heighten awareness amongst both the public and medical personnel.

Ticks are blood-feeding ectoparasites, closely related to mites and more distantly related to spiders and scorpions. They are not insects, but are arachnids, about the size of a pinhead. They feed by biting the skin and sucking blood from animals such as mice, and sometimes humans. In this way, some ticks get infected with the bacterium that causes Lyme disease. If an infected tick bites a human, then the bacteria may be passed into the human, but is not passed from person to person.

There are 20 species of tick distributed across the United Kingdom and, although present all year around, they are most likely to bite from February through to September.  In Britain, the sheep tick, Ixodes ricinus, is the most commonly encountered tick species.  Despite its name, it will feed from a wide variety of wild and domestic mammals, birds and humans. This tick is the main vector of Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum, Babesia divergens and ‘louping ill’ virus in Britain.

Ixodes hexagonus, the tick of the hedgehog, can be a significant parasite of companion animals, and was responsible for human infestations in World War II Anderson shelters where hedgehogs also sought refuge.

Ticks are often found in woodland, particularly deciduous or mixed woodland, rough upland or moorland pastures, heathland and grasslands, and can be also be present in urban/suburban parks and gardens.  Ticks are particularly abundant in the transition zone between two vegetation communities, such as woodland and meadow or shrub communities, which permit a wider range of potential hosts. Increasingly, ticks are being reported in gardens bordering woodland, and particularly those visited by deer. Ticks can be brought into gardens by wildlife and pets.

Areas in the UK where people acquire Lyme borreliosis include many popular holiday and outdoor activity destinations such as the New Forest, Exmoor, the Lake District, the Scottish Highlands and Islands, North York moors, Thetford Forest, and the South Downs.  Although these are high-risk areas for Lyme borreliosis, any area where Ixodid ticks are present should be regarded as a potential risk area. At least 50% of infections acquired in the UK are known to have occurred in the south of England. 

Typical Ixodes ricinus habitat Typical Ixodes ricinus habitat

The life cycle of Ixodid ticks has four stages: egg and 3 parasitic stages – larva, nymph (most likely to bite you) and adult. Many species of tick remain infected for the duration of their life, maintaining infection from one stage to the next, with some infected female ticks also transmitting infection to their offspring via their eggs.

In Britain the sheep tick, Ixodes ricinus, activity has been recorded sporadically at all times of the year, although generally larvae begin ‘questing’ (host-seeking) in spring/early summer (April/May), declining in September. Nymphs are active from February – October. Adult activity is similar to that observed in nymphs, occurring between February and September.

Active ticks ‘quest’ by clinging to vegetation at a height where they are most likely to encounter the host animal appropriate to their life stage; detecting passing animals by holding out their front legs where their sensory Haller’s organ is located; this sensory gland being acutely responsive to changes in carbon dioxide, heat, odour and physical disturbances.  Ticks quest until they either successfully attach to a host or have lost excessive amounts of water when they retreat to ground level where they will recover and later quest again. Ticks will die if they are unsuccessful in finding and attaching to a host before their energy reserves are used up.

Once a tick starts to feed, its body will become filled with blood. Adult females can swell to many times their original size. As their blood sacs fill they become lighter in colour and can reach the size of a small pea. Larvae, nymphs and adult males do not swell so much as they feed. If undisturbed, a tick will feed for around 5-7 days before letting go/dropping off.  Small children are generally bitten above the waist, including the hairline and scalp.

Three of the diseases that can be caught from infected tick bites in Great Britain are Lyme borreliosis, Babesiosis and Ehrlichiosis.  Globally, the list of diseases is much longer.  Some ticks may carry all three diseases at the same time, and may transfer them in a single bite.  The resulting symptoms can be confusing, liable to misdiagnosis and treatment in such cases can be difficult.

 

Real life cases of Lyme disease in runners

In 2004, Kirsty Waterson of St Edmunds Pacers running club, Suffolk, sought medical advice eight months after a rash developed above her ankle after the January Thetford Forest Race.  She was referred to a dermatologist, and after a series of blood tests Lyme disease was confirmed.  The condition was appropriately treated, but she was left with a recurring ‘glandular-fever-like’ syndrome.  In 2001 she ran for the GBR and N. Ireland Under-20s women in the World Cross-Country Championships.

Kirsty Waterson
Kirsty Waterson

Perry Louis Fields
Perry Louis Fields

Perry Louis Fields, now 33-years old, an elite US track athlete, who hails from Columbia, was bitten by a deer tick on the nape of the neck in 2003, after competing in the Grandfather Mountain Highland Scottish Games, USA.  She brushed the tick off and then developed a rash at the site of the bite and fatigue, similar to a flu-like illness.  She thought she had been training too hard.  The symptoms resolved for 2 years and resurfaced at the 2005 USA Outdoor Championships, when her limbs went numb and cold during the second lap of the 800m race.  She was diagnosed with the co-infection of Lyme disease and Rocky Mountain spotted tick fever (caused by the bacteria Rickettsia ricketsii).  The next three years were a real endurance challenge with symptoms of muscle and joint pain, extreme sensitivity to light touch and smells, debilitating chronic fatigue, vomiting and severe depression.  She received antibiotics and unconventional complementary therapies and is now running again after many years lost to the condition. In her 2012 book, ‘The Tick Slayer – Battling Lyme Disease and Winning’, Perry Louis Fields describes her experiences and the effects of the condition on her life and athletics.

Preventive measures to avoid tick bites

Effective self-protective measures include:

  • Use of repellent on skin (DEET – N, N-diethyl-meta-toluamide) and/or permitherin on clothing.
  • Avoiding contact with overhanging vegetation where ticks are likely to be questing.
  • Running/walking in the middle of the trail.
  • Wear long, light-coloured clothing to easily see ticks/brush them off before they attach to skin.
  • Tuck trousers into socks, shoes or trainers to minimise ticks under clothing.
  • Regular checks for ticks on clothing.
  • Avoid lying in grassy/wooded areas for post exercise stretching.
  • Full tick examination once leaving tick areas- prompt removal (< 24 hours) greatly reduces the risk of transmission of tick-borne infections.
  • Regular use of tick treatment on companion animals.
  • Excluding deer from garden areas.
  • Ensuring garden borders and lawns are kept short.

To remove a tick that is attached to your skin:

  • Gently grip the tick as close to the point of attachment to the skin as possible.  Preferably use fine-toothed tweezers or forceps, or a tick removal device available from vets and pet stores.
  • Pull steadily upwards, away from the skin. Take care not to crush the tick.
    For a diagram, see: www.lymediseaseaction.org.uk/information/tick_removal.htm

Tick removal tool and technique

Immediately after an attached tick has been removed from the skin, the site will continue to be a little red, perhaps for a couple of days – this is not in itself an indication of Lyme disease

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The O’Tom Tick Twister (set of 2 – large and small) demonstrated above, costs £4.50 plus P&P.

Lyme disease

The first symptom is usually the rash that spreads out from the site of the tick bite, without itching or pain, often called a bull’s eye rash, erythema migrans.

It usually takes 24 – 48 hours for bacteria in the tick to pass into the human after being bitten. Ticks are tiny and ‘cling on’ to the skin once they bite, then they 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 fed and are engorged. This normally takes about 24 hours, but can be less if the tick was already partially fed.  Therefore, if you remove a tick soon after being bitten (within 24 hours), you are much less likely to develop Lyme disease, even if it was an infected tick.  A course of antibiotics will usually clear the infection.

It is quite easy to have a tick bite without noticing e.g. on the leg or back, and many people who develop Lyme disease cannot remember being bitten.  Once bacteria are passed from the infected tick into your skin, they then multiply and travel in the bloodstream to other parts of the body to cause symptoms – often months after the initial tick bite.  The parts of the body that are mainly affected are the skin, joints, nerves and heart.

The symptoms and effects of Lyme disease can be divided into three stages:

Stage 1

Rash. The classical symptom of Lyme disease is the typical erythema migrans rash (see photo). This does not always occur. It probably occurs in between 3-8 out of 10 cases.  It usually develops several days after the bite, with a single, often-circular, red mark which spreads outwards slowly over several days. The circle gets bigger and bigger, with the centre of the circle frequently, although not always, being where the tick bite occurred. As it spreads outwards a paler area of skin emerges on the inner part of the circle; hence the term ‘bulls eye’ rash, which may be between 2-30cm in diameter, developing 2-30 days after the bite.  The rash is not usually painful or itchy and without treatment it typically fades within 3-4 weeks, but this does not necessarily mean the infection has cleared from the body.  Surveys have shown that around 50% of people with Lyme disease did not see a rash.

Flu-like symptoms occur in about half of cases. Symptoms include tiredness, general aches and pains, headache, fever, chills and neck stiffness. These symptoms are often mild and go within a few days even without treatment (but the infection may not have gone).

In some cases, the infection does not progress any further, even without treatment, as the immune system may clear the infection. In about half of cases that are not treated, the disease progresses to stage two.

Stage 2 – early disseminated disease

This may develop in untreated people weeks or months after the bite. Symptoms can include:

Joint problems – most commonly affecting the knee or jaw.  It is rare in patients with UK-acquired infection, but is more common when the disease is acquired in North America or some parts of Europe. The severity can range from mild joint pain, to severe arthritis, lasting up to three months.

Nerve and brain problems. Some affected people develop inflammation to nerves, particularly the nerves around the face e.g. facial palsy.  Meningitis and encephalitis may occur.

Heart problems. Some affected people develop inflammation of the heart muscle (myocarditis) and other heart problems, causing symptoms such as dizziness, breathlessness, chest pain and palpitations.

Rash. Several areas of the skin (not where the tick bite occurred) may develop a rash similar to erythema migrans. These ‘secondary’ rashes tend to be smaller than the original stage one rash, and tend to fade within 3-4 weeks.

Rarely, other organs such as the eyes, kidneys and liver are affected.

Stage three – chronic (persistent) Lyme disease

This may develop months to years after infection and may develop after an asymptomatic period.  Whole ranges of symptoms have been described in joints, nerves, brain and heart. The brain problems may include mild confusion, poor memory, concentration, mood, sleep, personality and/or speech problems.

Diagnosing Lyme disease

In most cases, Lyme disease is diagnosed in stage one of the disease by the typical rash +/- a flu-like illness, in someone who has been bitten by a tick. Other tests are not needed in this situation and treatment is usually given. The diagnosis of stage two or three is more difficult. Blood and urine tests and skin tests are helpful (but not always conclusive) in diagnosing the disease if it is suspected from the symptoms.  In the UK a 2-tier system of blood testing is operated:

Stage 1 – blood is sent to a local hospital for a screening test. If the result is equivocal or positive, then the sample is sent on to a specialist reference laboratory for testing specific to Lyme disease.

Stage 2 – the tests carried out at the reference laboratory will include a Western blot and may also include an Enzyme Immuno-Assay (EIA) test.

These blood tests detect antibodies to the bacteria, but may take 2-4 weeks to develop. If antibodies have not developed sufficiently it is possible for the test to be negative despite active infection.

The NHS Clinical Knowledge Summaries CKS [1] suggest that testing is not considered necessary for people with erythema migrans and a history of a tick bite or possible exposure to ticks, as this presentation is sufficient to make a clinical diagnosis of Lyme disease.  Testing in general practice can be considered for (a) people with a rash suggestive of erythema migrans but without a history of a tick bite or possible exposure to ticks and no other clinical features of Lyme disease and (b) people with isolated, unilateral facial palsy (as seen with Bell’s palsy) if it is thought that Lyme disease needs to be excluded because of a history of a tick bite or possible exposure to ticks.

For people with other types of neurological symptoms, or with rheumatological or cardiac symptoms, testing should usually only be carried out in general practice, following specialist advice. Many such people will require hospital admission or urgent specialist assessment.

Blood testing is not always accurate as there have been no UK studies. A recent paper analysed cases diagnosed with Lyme disease in a London hospital [2]. This reports that 11 people who had a negative screening test were thought by their doctors to have Lyme disease and their blood was sent for a Western blot test, despite the negative EIA. 6 out of the 11 with a negative screening test had a positive Western blot.  The antibody response takes several weeks to reach a detectable level, so antibody tests in the first few weeks of infection may be negative. It is rare for patients to have negative antibody tests in longstanding infections.

People may have antibodies to Borrelia burgdorferi without having a current infection. Those whose work (e.g. forestry), or place of residence (adjoining woodland, heathland or scrub), or recreational interests expose them to the risk of frequent tick bites, may have antibodies due to a previous infection that may have been unrecognised or even asymptomatic. In some cases the patient’s current clinical problem may be unrelated to the previous Bb infection.

Treatment for Lyme disease

A course of antibiotics will usually clear the infection. The type of antibiotic, and the length of the course can vary depending on individual circumstances.  Most people are diagnosed in stage one when treatment will clear the symptoms and prevent the development into stages two or three.

Prognosis of treatment

If treated with antibiotics in stage one of the disease, there is a very good chance of a complete cure with no further problems.  The earlier the treatment is started, the better the outcome. However, the optimum drug, dose and duration are not known.

If you are not treated in stage one, about 80% develop some symptoms of stage two or three. However, these are often mild and transient symptoms such as a skin rash or mild joint pain. Some people develop more severe symptoms if they progress to stage two or three. Treatment with antibiotics during stage two or three is also usually curative, but may need to be prolonged.

Some people report ongoing symptoms that may be triggered by Lyme disease even when the infection has been treated with antibiotics. This has been called ‘post-Lyme disease syndrome’. Medical opinion is divided on whether ongoing symptoms are due to inadequately treated infection, or to another cause such as an autoimmune condition i.e. the immune system not ‘switching off’ even when the bacteria causing the infection have been cleared. Symptoms of ‘post-Lyme disease syndrome’ that have been reported include tiredness, joint or muscle pains, headaches, hearing loss, vertigo, mood disturbances, pins and needles and insomnia – resembling chronic fatigue syndrome or fibromyalgia. [3, 6].

For anything but early treatment at the erythema migrans stage, CKS recommends referral to a specialist.

Choice of antibiotic

It is important to have a drug with good tissue penetration, intracellular action and good cerebrospinal fluid (CSF) penetration. The antibiotics normally quoted in guidelines are doxycycline, amoxicillin, cefotaxime or ceftriaxone as these drugs have been used in clinical trials. Because the trials have shown very variable outcomes (38-100% successful outcome), and because investigations have shown that the bacteria can survive conventional courses [3] many doctors and researchers are looking for better treatment.

There is an opinion that metronidazole and tinidazole may be necessary against the cyst form of the bacteria [4]. There is also a view that drugs such as azithromycin, which show very high effectiveness in the laboratory [5], may have a place in treatment. Neither class of drug has yet been tested in clinical trials in patients with Lyme disease.

The European Federation of Neurological Societies EFNS [7] state, under a discussion of effective agents in late Lyme NeuroBorreliosis (LNB) that “there are no randomised treatment studies of European late LNB”.

Dose and duration of treatment

Because of the many treatment failures in clinical trials, it has been suggested that higher doses may be necessary to effectively eradicate the bacteria, but there have been no European trials exploring this.

Because the bacteria can penetrate the spinal fluid it is important that high enough antibiotic concentrations are reached in the cerebrospinal fluid (CSF). Research has shown that doxycycline at 200mg twice a day achieves the necessary levels in the CSF much faster than with the often recommended 100 mg twice per day [6]. This is likely to be important in short courses of 14-28 days but, because of the long half-life of doxycycline, may not be so important in longer courses; evidence is lacking.

The EFNS guidelines [7] state “There are no comparative controlled studies of treatment length in European late LNB” (symptom duration > 6 months).  The view of many doctors is that duration of therapy should be guided by clinical response.  Patients might experience a worsening of symptoms on starting treatment – the Jarisch-Herxheimer Reaction. CKS [8] only mentions this with respect to pregnant women, but it applies to all patients.  CKS states “People may mistake this for an allergic reaction and stop their antibiotics. Provided the symptoms are not severe, and there is no evidence of an allergic reaction (such as urticaria = ‘hives’), they can continue treatment.”

Conclusion

With the uncertainty about late diagnosis and lack of a guaranteed efficacious treatment, heightened awareness of ticks, their bites and Lyme disease may be the mainstay of reducing the numbers affected by the disease, and also the anxiety surrounding visits to the habitats where the sheep tick resides.

 

References

1) Clinical Knowledge Summaries  (CKS)

2) “Lyme disease in the U.K.: clinical and laboratory features and response to treatment., Richard Dillon, Susan O’Connell, and Stephen Wright, “Lyme disease in the U.K.: clinical and laboratory features and response to treatment.,” Clinical medicine (London, England) 10, no. 5 (October 2010): 454-7, http://www.ncbi.nlm.nih.gov/pubmed/21117376

3) Honegr, K, D et al. 2004. “Long term and repeated electron microscopy and PCR detection of Borrelia burgdorferi sensu lato after an antibiotic treatment.” Central European journal of public health 12 (1) (March): 6-11.

4) Brorson & Brorson 2004. An in vitro study of the susceptibility of mobile and cystic forms of Borrelia burgdorferi to Tinidazole. International Microbiology 7:139–142

5) Hunfeld & Brade 2006 Antimicrobial susceptibility of Borrelia burgdorferi sensu lato: What we know, what we don’t know, and what we need to know. Wien Klin Wochenschr 118/21–22: 659–668

6) Dotevall & Hagberg 1989 Penetration of Doxycycline into Cerebrospinal Fluid in Patients Treated for Suspected Lyme Neuroborreliosis. Antimicrobial Agents and Chemotherapy, July 1989, p. 1078-1080

7) Mygland et al 2010 EFNS guidelines on the diagnosis and management of European Lyme neuroborreliosis. European Journal of Neurology 2010, 17: 8–16

8) CKS

Sources of information for this article:

Bootcamp Ascot www.bootcampascot.co.uk

Patient.co.uk www.patient.co.uk/health/Lyme-Disease.htm

Lyme Disease Action www.lymediseaseaction.org.uk/

Lyme Disease Action is a group of people who have been affected by the disease.  In 2001, the foundation of EuroLyme, an Internet patient support group, was formed.  It became apparent to the on-line participants that numbers were growing, and that a formal organisation was needed to lobby for the treatment of patients, raise awareness and strive for more medical research. A small group of EuroLyme members decided to form the registered charity Lyme Disease Action in 2003.

The Health Protection Agency (HPA): www.hpa.org.uk/Topics/InfectiousDiseases/InfectionsAZ/LymeDisease

‘How a tick bite destroyed the career of an athletics champion’     20th June 2006: www.dailymail.co.uk/news/article-391579/How-tick-bite-destroyed-career-athletics-champion.html

Perry Louis Fields www.perryfields.com/

Borreliosis and Associated Diseases Awareness UK (BADA-UK) and O’Tom Tick Remover: www.bada-uk.org/products/tickremover.php

Tick awareness leaflet (HPA) from the Health Protection Agency.

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