Lyme disease

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ΕΤΥΜΟΛΟΓΙΑ

First described in Lyme County, Connecticut. See Google Maps - Lyme County

Infection 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 if given early. Problematically serology only means exposure at some point and chronic disease is complex and still poorly understood. Borrelia burgdorferi sensu lato complex and Borrelia bissettii have now been described to have non classic presentations (chronic fatigue type) with live bacteria isolated[1].

Aetiology

Caused by several Borrelia varieties of which at least 7 infect man, 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.See Boreelia for more details on pathogenity of individual species and genotypes.

Contents


Clinical

Epidemiology

Commonest in spring and summer and in children and young adults. Major natural reservoirs are small mammals. Geographic variation in typical presentations

Characteristic Rash

Erythema migrans (EM, 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 starting 2 to 32 days after the bite. 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. Resolution can take up to 4 weeks and the lesion can be more than 60cm (2 feet) at its maximum diameter. It may be painess, pruritic and rarely painful.

Other skin presentations

Tend to be more common in Europe due to more Borrelia afzelii. Include acrodermatitis chronica atrophicans(ACA) and lymphadenosis benigna cutis

Late Effects

Arthritis, endocarditis, hepatitis and pneumonitis may occur. Neuropathy/radiculopathy are seen in US, rarely in Europe. However Borrelia garinii a major cause of Lyme disease in Europe does cause neuroborreliosis commonly. The Americian strains are associated with CNS disease in up to 15% of cases with a lymphocytic meningitis and rarely myelopathy or focal encephalomyelitis[2]

"A verified diagnosis of Lyme neuroborreliosis had no substantial effect on long term survival, health, or educational/social functioning. Nevertheless, the diagnosis decreased labour market involvement marginally and was associated with increased risk of haematological and non-melanoma skin cancers."[3]
LogoKeyPointsBox.pngThe 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.

Differential

The differential diagnosis is wide and includes other tick transmitted disease. These include:

Investigations

Refer to CDC criteria for active disease. If classic ECM seen then no need for blood tests (although Amblyomma americanum (lone star tick) 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 and vague associations common; but retreatment, even parenteral, no better than placebo. Accordingly treatment late has greater risk of new side-effects from antibiotics.

Prophylaxis

Although a single 200mg dose of doxycycline after a tick bite works the low infectivity of individual tick bites means this is not usually practicable and in any case can not be used in young children or pregnant women. 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.[4]
  • 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."[5]

If fragments of the tick's mouth parts 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

  1. In the event of a tick attaching itself, early removal may be sufficient to prevent infection. A cinical evidence review[6] suggested that for ticks present for 72 hours a prophylactic course of an antibiotic may be beneficial.

Notification

ICD code

A69

Quackery and "Alternative"

QuotationMarkLeft.png 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. QuotationMarkRight.pngCMO Update, August 2009[7]

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.[8]

External links

References

  1. Rudenko N, Golovchenko M, Vancova M, Clark K, Grubhoffer L, Oliver JH. Isolation of live Borrelia burgdorferi sensu lato spirochetes from patients with undefined disorders and symptoms not typical for Lyme borreliosis. Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases. 2015 Dec 7.(Epub ahead of print) (Link to article – subscription may be required.)
  2. Case21-2007 N Engl J Med. 2007;357(2):164-73.
  3. Obel N, Dessau RB, Krogfelt KA, Bodilsen J, Andersen NS, Møller JK, et al. Long term survival, health, social functioning, and education in patients with European Lyme neuroborreliosis: nationwide population based cohort study. BMJ 2018;361, DOI: 10.1136/bmj.k1998 (https://www.bmj.com/content/361/bmj.k1998).
  4. 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)
  5. Pitches DW. Removal of ticks: a review of the literature. Eurosurveillance 2006;11(7-9):196-8
  6. http://www.clinicalevidence.com/ceweb/conditions/ind/0910/0910.jsp
  7. Donaldson L. Testing for Lyme disease. CMO Update 2009(49):4.
  8. [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
  9. 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.)