What do we want to know?
Lyme disease is the result of a bacterial infection which is common in ticks; people can develop Lyme disease after being bitten by an infected tick. Evidence indicates that rates of Lyme disease may be increasing but it is unclear how widespread the disease is in the UK. Similarly, there is uncertainty about the most effective ways to prevent, diagnose and treat Lyme disease as well as a lack of understanding about patient and professional experiences of the disease. To address these gaps in knowledge we undertook a project to identify existing research evidence focusing on:-
- The nature and extent of research evidence on Lyme disease in humans;
- The incidence of Lyme disease in the UK and the type of surveillance systems in different countries;
- Patient, clinician and researcher experiences of Lyme disease diagnosis;
- Patient, clinician and researcher experiences of Lyme disease treatment; and
- The effectiveness of different approaches for preventing Lyme disease.
These reviews were undertaken alongside reviews conducted by NICE on the accuracy of diagnostic tests and the effectiveness of different treatments for Lyme disease.
Who wants to know?
This project was commissioned by the Department of Health in England, and will be of interest to policymakers, healthcare practitioners, patients and researchers.
What did we find?
The nature and extent of research evidence on Lyme disease:- We identified 1,098 studies, with a steady increase in number since 2002. Most papers are from Europe, and the USA. The focus is mainly on diagnosis, symptoms and co-occurring conditions or Lyme disease incidence. There is less focus on Lyme disease prevention, treatment, risk factors or costs.
Incidence of Lyme disease in the UK and the type of Lyme disease surveillance systems in different countries:- Routine data indicate that each year in England and Wales just under 2 people per 100,000 are infected with Lyme disease. The rate has increased slowly but consistently over the last decade. The rate in Scotland is higher but has declined since a peak in 2008-10. The rate in Northern Ireland is very low. Research indicates that there may be geographical ‘hotspots’ where local incidence is much higher than found in routine data, such as in the Highlands of Scotland.
Most countries in Europe and North America have some form of surveillance for Lyme disease. In some countries clinicians must notify the authorities if they diagnose a patient with Lyme disease, and in other countries laboratories that test for Lyme disease must also notify authorities. Few systems rely, as the UK does, on laboratory notification alone. Overall, research suggests that most types of surveillance system miss some cases of Lyme disease and that clinician reporting is not superior to laboratory reporting in terms of under-reporting.
Patient, clinician and researcher experiences of diagnosis of Lyme disease:- Patients, clinicians and researchers report experiencing uncertainty about the diagnosis of Lyme disease. This stems from concerns that laboratory tests are not always accurate, inconsistencies in the interpretation and timing of tests, low-levels of knowledge among clinicians and challenges due to the wide range of symptoms. Patients and clinicians report that uncertainties can negatively affect clinician-patient relationships which, in turn, can lead to unproductive healthcare use and costs to society. UK based patient advocacy groups endorsed these findings as reflecting their own experiences.
Patient, clinician and researcher experiences of treatment of Lyme disease:- Research evidence was lacking and we were unable to produce a review of treatment experiences.
The effectiveness of different approaches for preventing Lyme disease:- Personal protection (such as wearing insect repellent or protective clothing) may prevent Lyme disease. Education strategies may improve adults’ knowledge about Lyme disease but for children the evidence is less clear. Even when knowledge is improved this does not seem to result in fewer tick bites or cases of Lyme disease. Evidence on other approaches such as vaccination and control of tick populations was limited. The evidence for all approaches was generally of poor quality and none of the studies were from the UK.
What are the conclusions?
- We identified key evidence gaps about treatment and prevention.
- The incidence of Lyme disease in the UK is increasing but is still low by comparison with some areas of Europe and the USA. Under-reporting of cases is likely in the UK, and elsewhere.
- A better understanding of how to deal with the negative impact of uncertainties surrounding Lyme disease diagnosis is needed.
- Research on patient and clinician experiences of treatment for Lyme disease is urgently needed.
- Evidence on the prevention of Lyme disease comes from methodologically weak studies but suggests that personal prevention should continue to be promoted, as should education about Lyme disease for adults.
How did we get these results?
We searched 17 electronic databases and conducted additional web-based searching. We included papers on Lyme disease in humans that were published in 2002 or after. To understand the nature of the research we described or ‘mapped’ the papers according to their main topic focus (e.g. Lyme disease diagnosis, treatment or prevention) and reported other aspects such as country and characteristics of the study participants.
Relevant studies from within the map were used to undertake individual evidence reviews on incidence, diagnosis, treatment and prevention of Lyme disease. Each review used methods appropriate to the type of evidence included. The review on the incidence and surveillance of Lyme disease narratively synthesised research evidence and supplemented this with other types of evidence, including routinely collected incidence data from the UK. The diagnosis review included studies in which patients or clinicians were asked about their experiences of Lyme disease diagnosis; we used thematic analysis to bring the findings of different studies together. A similar approach was planned for the review on treatment, but lack of evidence prevented us carrying out a synthesis. For the review on prevention, data on the effectiveness of interventions were synthesised narratively and cross-referenced with current prevention guidelines.
These reports should be cited as:
Stokes G, Blanchard L, Sutcliffe K, Dickson K, Brunton G, Burchett H, Jones-Diette J, Hinds K, Khatwa M, Lorenc T, Khouja C, Walker R, Rojas-Garcia A, Rees R, Harden M, Stansfield C, Sowden A, Thomas J (2017) A systematic evidence map of research on Lyme disease in humans. London: EPPI-Centre, Social Science Research Unit, UCL Institute of Education, University College London.
[Evidence Map supplementary files: (1) list of mapped references, (2) characteristics of mapped references.]
Lorenc T, Jones-Diette J, Blanchard L, Sutcliffe K, Stansfield C, Harden M, Sowden A and Thomas J (2017) Incidence and surveillance of Lyme disease: systematic review and policy mapping. London: EPPI-Centre, Social Science Research Unit, UCL Institute of Education, University College London.
Brunton G, Sutcliffe K, Hinds K, et al. (2017) Stakeholder experiences of the diagnosis of Lyme disease: a systematic review. London: EPPI-Centre, Social Science Research Unit, UCL Institute of Education, University College London.
[Errata: the first version of the file above, on page 39, stated (emphasis added): "[...] e-learning package on Lyme disease, in collaboration with Lyme Disease UK (Royal College of General Practitioners and UK 2014)". This has now been corrected to: "[...] e-learning package on Lyme disease, in collaboration with Lyme Disease Action (Royal College of General Practitioners and Lyme Disease Action 2014)". The corrected file is now linked above and marked with “.V2.pdf” in the filename, this correction was made on 21/12/2017 at 3:16 PM GMT.]
Sutcliffe K, Sowden A, Burchett H, Stansfield C, Harden M, Thomas J (2017) Patient, clinician and researcher experiences of the treatment and management of Lyme disease: a systematic review. London: EPPI-Centre, Social Science Research Unit, UCL Institute of Education, University College London.
Richardson M, Khouja C, Walker R, Sutcliffe K, Stansfield C, Harden M, Sowden A, Thomas J (2017) Prevention interventions for Lyme disease: a systematic review. London: EPPI-Centre, Social Science Research Unit, UCL Institute of Education, University College London.