Lyme disease is one of several bacterial infections which can be passed to humans by the bite of an infected tick. It is important to be aware of it, and the potential risks posed by a tick bite, because it is a multi-systemic infection which can affect the central nervous system, muscles (including the heart) and cognitive function of the brain: it can be severely disabling, long lasting and potentially fatal. Therefore early diagnosis, and prompt treatment, is crucial to minimising the effects of disease.
Knowledge about Lyme disease in the UK NHS is patchy. Although N.I.C.E, The National Institute for Care and Health Excellence, issued a guideline in 2018, knowledge at the “coalface” of NHS Primary Care remains inconsistent, and prompt diagnosis and effective treatment are not assured. Therefore the first line of defence is to avoid being bitten. Nobody wants to stop people enjoying the open air. The physical and psychological benefits of enjoying the countryside outweigh the risks, but you need to take sensible precautions. Wear appropriate clothing: long sleeves, trousers with cuffs tucked into socks: not shorts, sandals and sleeveless ‘crop tops’. Use a DEET based tick repellent on exposed skin, but remember it may need to be reapplied if you are out all day.
If you might be at tick risk, say on a day out in the countryside, it is good practice to check yourself thoroughly at the end of the day, and at intervals through the day to check your clothes for ‘questing’ ticks. You may need the assistance of a good friend: ticks can hide in places hard to see. Remember that a tick which can carry disease may be as small as a poppy seed, but if you find a tick attached don’t panic: they don’t all carry disease. Although disease transmission can begin in as little as 6 hours, it is as important to remove an attached tick correctly as it is to remove it promptly. Use of the correct technique, preferably with a purpose designed tick removal tool or needle-nosed tweezers, is vital to avoid crushing the tick and provoking it to pass any bacteria to you. Do not use your fingers, apply creams, Vaseline, alcohol or attempt to burn it off with a match head or cigarette end.
Ticks are not “spreading north”, as has been rather sensationally described recently. The UK has, and has had for many millenia, ticks widely distributed. Although we know their preferred habitat is leafy woodland, heathland, and long vegetation, anecdotally ticks are becoming more active over a wider geographical range and longer across the seasons. Again, anecdotally, 2018 seems to have been a ‘bad’ year for ticks. It is not known whether this is because of global warming, changes in land use, changes in agricultural practices or some other reason. Some say that a so-called “Mast year”, when a big crop of tree nuts is produced, or an abundant autumn results in survival of more vector species like mice. While there are so-called ‘hot spots’, even within ‘tick country’ like the Highlands, or the New Forest, it is not really known where they are in greater or lesser numbers or whether the ticks there are proportionally more or less infected than elsewhere. In fact there is no reliably accurate information on the proportion of UK ticks that carry disease. Estimates range from 2-15%.
The fact is you don’t need to be wild walking or camping to find a tick. You could get bitten by an infected tick in your urban garden, allotment or an urban park, because they can travel on mice, hedgehogs, domestic pets, urban foxes and even migrating birds. At present there is no mandatory check for ticks on pets returning from a foreign ‘holiday’ and some species of imported ticks can survive indoors, unlike our ‘domestic’ ticks which need moisture to survive, and they can carry disease pathogens not normally present in the UK.
The official estimate of new cases of Lyme disease, in the UK, annually is about 3000. Until very recently the Centre for Disease Control (CDC) in the USA estimated cases there as 30,000. They have revised that to 300,000. There appear to be more cases Lyme disease (and other tick borne diseases) in mainland Europe than the UK, but that may be because other countries collect data differently. The wide range of estimates of new UK cases is, regrettably, just estimates. Any apparent increase in cases may be down to increased awareness, both in the public and the medical profession. Since 2010 Lyme disease has not been a notifiable disease in the UK, unless acquired occupationally when it would be reported to the HSE (Health and Safety Executive) under the RIDDOR regulations, or in military service. Data are not collected in the UK unless the disease is confirmed by a UK laboratory blood test. An unknown proportion of cases are treated on clinical judgement without a confirming blood test. This needs to change if we are to understand the scale of the incidence of UK acquired Lyme disease.
Both Public Health England (PHE), and The Big Tick Project (based in Bristol) receive ticks collected by members of the public in the UK. PHE will examine the ticks it receives to see what disease pathogens they carry. Anything, like an app, that more reliably records where, and in what numbers, ticks are found may be helpful. Indeed there have been apps developed in the UK before, and there are a number of so-called ‘tick MAPS’ to be found on the internet. Unless the information is properly recorded, in a standard format, it may not provide scientifically reliable data. Incomplete information can also lull people into a false sense of security if they are led to believe they are in a low risk area.
There is, as yet, no vaccine against Lyme disease. Scientists and Doctors are beginning to accept that their previous certainty about detection and treatment of Lyme disease is less secure. There is more open-mindedness about the sensitivity and reliability of standard tests. The 2018 N.I.C.E guideline acknowledges continuing uncertainty, including about the potential for complete cure, about relapses or about the persistence of the bacteria. At least there is more willingness to consider different drugs, doses, duration and method of delivery of treatment.
Whatever the accurate number of new UK cases, every year there is a fresh cohort of victims: new blood samples, new prescriptions of drugs, new outcomes. Because there is no centrally directed or co-ordinated recording, monitoring of diagnosis, treatments or outcomes, there is no dataset of Lyme disease victims available to researchers to see whether one treatment works better than another, whether there is a measurable treatment failure rate, or for evidence of relapse or post-treatment persistence.
A large number of Lyme ‘victims’ have, over many years, reported persisting illness despite approved treatment. Naturally, in desperation, and with the help of the internet, they look elsewhere for help. This has led to a rise in the number of ‘alternative’ or ‘unorthodox’ treatments being offered and tried, some of them positively dangerous. While, for the most part, there is little evidence that these work it is well to remember that “absence of evidence does not mean evidence of absence”. In due course it may be proven, by more research and clinically controlled double-blind trials, that there is scientifically replicable evidence. Without such evidence the orthodox medical community, and regulatory bodies, will always rely on the official guidance.
The longer someone has disease without treatment, the more intractable it can become. Given the potentially large number of under, or undiagnosed, victims there may need to be more work on so-called late stage, or disseminated, Lyme involving referrals to specialist clinics and a multi-disciplinary approach. One of the things we do know is that, amongst recorded and confirmed cases, the age group most at risk of developing the disease appears to be 45-64. We do not know why this is, but we do know that we have an ageing population so it is not unreasonable to extrapolate from this that, if for no other reason, there will be more cases in future.