Lyme disease
From Ganfyd
ΕΤΥΜΟΛΟΓΙΑ
First described in Lyme County, Connecticut. See Google Maps - Lyme CountyInfection carried by ticks, due to the Borrellia spirochaetes, principally Borrelia burgdorferi. Patients often do not remember having a tick bite, and the characteristic rash is not always noticed. Hence central nervous system and joint involvement may develop later. Treatment with a suitable antibiotic, typically doxycycline, is effective.
Aetiology
Caused by several Borellia varieties, Borrelia burgdorferi being the most severe and classically described, spread by Ixodes tick. Nymphs (tiny first stage of life cycle) more likely to spread infection than adults (probably because not so easily seen and hence not removed, rather than borrelia load) hence spring peak. A significant proportion of patients will not remember having had a tick bite.
The varieties most common in the UK are not those associated with the most severe disease.
Web Resources for Lyme disease (search term=Lyme_disease)
ICD 10 code: A69
Relevant Clinical Literature
UK Guidance
Other Wikis
Medpedia on Lyme disease (Less technical, good quality control)
Wikipedia on Lyme disease (Less technical, ? quality control)
Contents |
Clinical
Characteristic Rash
Erythema Chronicum Migrans (ECM, needs a picture - or see pictures at CDC website) is a ring-shaped lesion, usually about 5cm wide but gradually increasing over a period of weeks. Smaller lesions at the site of the tick bite may just be inflammatory reactions. ECM can be multiple, and can be found away from the site of the bite.
Late Effects
Arthritis, endocarditis, hepatitis and pneumonitis may occur. Neuropathy/radiculopathy are seen in US, rarely in Europe. The Americian strains are associated with CNS disease in up to 15% of cases with a lymphocytic meningitis and rarely myelopathy or focal encephalomyelitis[1] | The organism is a Spirochaete, so finding it lingering and causing odd effects should not surprise us. But not all odd lingering is likely to be due to Lyme Disease. |
Investigations
Refer to CDC criteria for active disease. If classic ECM seen then no need for blood tests (although A. americanum produces similar lesion in US)!
Blood tests
Serology (EIA) IgM at 2/52 but high false pos/neg, and early treatment may prevent seroconversion, so Western blot to confirm. Potentially co-infection with babesia and anaplasma (in US) - consider if unusually sick or bone marrow failure. Consider lumbar puncture for CSF EIA.
Treatment
Medical
Treatment failure of acute disease suggests misdiagnosis! Use Doxycycline (except in children) else high dose Amoxicillin for 14 days. Macrolides are less effective! If IV needed (eg heart block or neurological disease), then ceftriaxone most often used so treatment can be on outpatient basis.
- Lesions take 1-2 weeks to heal.
- Jarisch-Herxheimer reaction can occur with increased erythema and systemic symptoms.
- Chronic fatigue common; but retreatment, even parenteral, no better than placebo.
See Infectious Diseases Society of America guidelines.
Radiology
Surgical
Prevention
- In areas where there are sheep or deer ticks (Ixodes species) wearing robust clothing and tucking trousers into boots helps prevent tick bites. Use of tick repellents also provides some (more limited) protection.[2]
- A vaccine is in early stages of development.
- Prophylactic doxycycline effective (NEJM) but attack rate without prophylaxis only 2.5% even in hyperendemic region: NNT=30. Incidence in New York State 10x higher than UK.
Tick removal
A recent literature review concluded that:
"since many people, particularly travellers who are not familiar with an area, will not be able to distinguish between different types of tick or know the local prevalence of disease, it seems sensible to recommend always removing ticks by grasping with forceps as close to the skin as possible and pulling straight out to avoid leaving mouthparts behind."[3]
- A "tick twister" may help; although apparently an orange needle can be almost as effective.
- CDC guidance on tick removal
- New Forest District Council leaflet (via HPA website)
If fragments of the tick's mouthparts remain in the bite it is not thought to increase the likelihood of transmission of borrelia, or therefore of Lyme disease. There is as good an argument for removing foreign bodies from a wound as for any other wound or body, but little merit in attempting it in the field.
Post exposure prophylaxis
- In the event of a tick attaching itself, early removal may be sufficient to prevent infection. A cinical evidence review[4] suggested that for ticks present for 72 hours a prophylactic course of an antibiotic may be beneficial.
Notification
ICD code
Quackery and "Alternative"
Lyme disease, caused by Borrelia burgdorferi and transmitted by the bite of an infected tick, is the most significant vector-borne infection in the United Kingdom and continues to receive media attention. Cases occur predominantly during the late spring, early summer and autumn, during peak tick feeding season. High-risk areas for Lyme disease in the United Kingdom are the New Forest, Exmoor, woodland or heathland areas of southern England, the Lake District, the Scottish Highlands and Islands, the North York Moors, Thetford Forest and the South Downs. At least 15% to 20% of laboratory-confirmed infections are acquired abroad.
The Department of Health remains concerned about the growing number of patients, particularly those suffering from chronic conditions such as myalgic encephalopathy (ME) or chronic fatigue syndrome, who receive a false diagnosis of Lyme disease from private laboratories offering unvalidated tests that lack the sensitivity and specificity to detect B. burgdorferi. A report of the Department’s investigation into the use of such tests in the diagnosis of Lyme disease is available at www.dh.gov.uk/assetRoot/04/13/89/17/04138917.pdf
Misinformation about Lyme disease is readily available to patients via the internet and can lead them to seek inappropriate diagnosis and treatment.
Comprehensive guidelines for clinicians on the diagnosis and treatment of Lyme disease are published on the Health Protection Agency’s (HPA) website. The HPA’s Lyme Borreliosis Specialist Reference Unit in Southampton provides validated tests for the NHS that comply with internationally agreed criteria for the detection of B. burgdorferi. Those claiming to have ‘chronic Lyme disease’ or who believe it to be the cause of their chronic condition can be diagnosed definitively through using the HPA’s tests.
Lyme disease is usually treated effectively by a short course of antibiotics; however, in a small number of cases, if left undiagnosed for a long period, Lyme disease can be difficult to treat. There is no biological evidence of symptomatic chronic Lyme disease amongst those who have received the recommended treatment regimen. 
- CMO Update, August 2009[5]
There is a lot of quackery including the odd assertion that Borrelia is a man-made bacterium. The variability of the test contributes to this.
Some people who believe that chronic lyme disease is a major problem appear to have resorted to the use of misleading propaganda.[6]
External links
- HPA Lyme Borreliosis Specialist Reference Unit Southampton Laboratory Level B South Laboratory Block Southampton General Hospital Southampton SO16 6YD
tel: 023 8079 6408 - Guidelines for clinicians on diagnosis and treatment from the Health Protection Agency
- Advice on Lyme disease for travellers and health professionals
- Lyme disease information from US CDC
- Infectious Diseases Society of America's evidence-based Lyme Disease guidelines[7]
- Webcast, slides and transcripts of the Infectious Diseases Society of America Lyme Disease Review Panel Hearing, July 30, 2009
- Lyme Disease Action - they have several fact sheets
- Information on Lyme disease (with good pictures) from Todar's Online Textbook of Bacteriology
- Information on Lyme disease from Netdoctor.co.uk
- Information on unorthodox Lyme laboratory tests from the UK Department of Health
References
- ↑ Case21-2007 N Engl J Med. 2007;357(2):164-73.
- ↑ Vázquez M, Muehlenbein C, Cartter M, Hayes EB, Ertel S, Shapiro ED. Effectiveness of personal protective measures to prevent Lyme disease. Emerg Infect Dis (serial on the Internet). 2008 (Feb);14(2):210-6 (last viewed 30 Jan 2008)
- ↑ Pitches DW. Removal of ticks: a review of the literature. Eurosurveillance 2006;11(7-9):196-8
- ↑ http://www.clinicalevidence.com/ceweb/conditions/ind/0910/0910.jsp
- ↑ Donaldson L. Testing for Lyme disease. CMO Update 2009(49):4.
- ↑ [http://boards.medscape.com/forums?128@805.vUMMarYkqHs@.29fe646b!comment=1 Crislip M. Lying liars and their lying lies. 2010 (May 25) Medscape "Rubor, Dolor, Calor, Tumor" blog.] (See also Calor, Dolor, Rubor, Tumor
- ↑ Wormser GP, Dattwyler RJ, Shapiro ED, Halperin JJ, Steere AC, Klempner MS, Krause PJ, Bakken JS, Strle F, Stanek G, Bockenstedt L, Fish D, Dumler JS, Nadelman RB. The clinical assessment, treatment, and prevention of lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America. Clinical infectious diseases : an official publication of the Infectious Diseases Society of America. 2006 Nov 1; 43(9):1089-134.(Link to article – subscription may be required.)
