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  • 1. LymeDisease Paul Mead, MD, MPH Division of Vector-borne Diseases Centers for Disease Control and Prevention

2. Lyme disease cause and discovery

  • Caused by a spiral bacteria,Borrelia burgdorferi
  • First described in 1976 as cluster of arthritis among children in Lyme, Connecticut
  • Soon recognized as multi-system disease in US and Europe linked to tick bite

Photo credit: Jay Carroll 3. Common human-biting ticks in the U.S. Transmit Lyme disease 4. Lyme disease transmission cycle Risk of human infection greatest in late spring and summer 5. Signs and symptoms of Lyme disease in humans 6. Erythema migrans (EM)

  • 70-80% of cases
  • Rarely painful
  • Appears ~7-14 days after tick bite
  • Expands slowly over days
  • Distinct from allergic reaction

7. Other presentations of EM From: Nadelman RB, Wormser GP. Management of tick bites and early Lyme disease,Lyme disease . 1998; Philadelphia: American College of Physicians. 49-75 8. Later stages of Lyme disease Arthritis Facial palsy 9. Lyme disease cases reported to CDC, United States, 1992-2008 Increase in reports due to more complete surveillance, plus expansion in some areas 10. Reported Lyme disease cases, United States, 2008 11. Reported Lyme disease cases, Northeastern United States, 2008 12. Lyme disease incidence by age and sex, United States, 1992-2006 13. Reported Lyme disease cases by onset month, United States, 1992-2006 14. Clinical features of reported Lyme disease cases, United States, 1992-2006 N = 150,829 15. Diagnosis

  • Lyme disease is diagnosed by considering:
    • symptoms and physical findings
    • likelihood of exposure
    • appropriate laboratory testing
  • In an endemic area, EM alone is considered diagnostic without the need for blood testing
  • Other forms of illness not sufficiently distinctive to confirm diagnosis without lab testing

16. Laboratory testing for Lyme disease

  • Mainstay is a blood test like those used for HIV, viral hepatitis, syphilis, toxoplasmosis, etc.
  • Detects antibodies the immune system makes against the organism
    • not positive until several weeks into the infection
    • remains positive for months or years after the infection is cured

17. 2 step process recommended

  • Similar to HIV testing
  • Step 1 is quantitative to determine if antibody levels are elevated
  • Step 2 is qualitative to determine if antibodies are specific for Lyme disease
  • Skipping either step increases false positives
  • IgM test only meaningful during first month of illness

ELISA / EIA negative positive or indeterminateIgM Immunoblot Stop IgG 18. How good is 2-tier testing? Bacon et al. JID 2003; 187:118799

  • A negative test does not exclude infectionin patients who have been ill less than a few weeks
  • A negative test strongly suggests against infection in patients who have been ill longer than a few weeks

Lyme Disease Stage Patients who test positive Acute EM38% Arthritis97% Late neurological 100% 19. Alternative tests

  • Dont use tests whose accuracy and clinical usefulness have not been adequately validated, including:
    • urine antigen tests
    • lymphocyte transformation assays
    • Westernblot using criteria not validated and published in peer-review scientific literature

20. Treatment and outcome

  • Lyme disease is treated with antibiotics
  • Recommended regimens range from 2-4 weeks, by pill or intravenously, depending on stage of illness
  • Most patients treated with antibiotics recover completely
  • A few patients, particularly those diagnosed with later stages of disease may have persistent symptoms
      • objective (e.g., facial paralysis, arthritis)
      • subjective (e.g., fatigue, muscle aches, reduced concentration)

21. Symptoms after treatment forLyme disease Long term follow up of 96 patients with culture-confirmed EM in 1991-4 Nowakowski et al.Am J Med 2003; 115:91-96 22. Post Lyme disease syndromeand Chronic Lyme disease

  • Terms used to describe patients with persistent subjective symptoms after recommended treatment
  • Questionis notwhether such patients exist
  • Questions are:
      • what is the cause of these symptoms?
      • are additional antibiotics the best treatment?
  • Placebo-controlled studies have found no sustained benefit to prolonged antibiotic treatment
      • prolonged antibiotic treatment not recommend

23. Principles of prevention

  • Personal protection

2.Environmental management 3.Community intervention 24. 1.Personal protection

  • Avoid tick habitat
    • ticks prefer wooded and bushy areas with high grass and lots of leaf litter
    • walk in the center of the trail to avoid contact with brush
    • take extra precautions in May, June, and July when nymphal ticks most active

25. 1.Personal protection

  • Use repellent
    • 20-30% DEET on skin and clothing
    • permethrin on clothes only

26. 1.Personal protection

  • Check for ticks daily
    • inspect body carefully including armpits, scalp, groin
    • ticks must attached for 36+ hours to transmit Lyme disease
    • prompt removal reduces risk of infection, even if the tick is infected

27. Tick Removal

  • Use fine-tipped tweezers to grasp tick close to skin
  • With a steady motion, pull tick away from skin
  • Clean skin with soap and warm water
  • Avoid crushing the ticks body
  • Dont use petroleum jelly, a hot match, nail polish, or other products to remove ticks

28. 1.Personal protection

  • Avoid tick habitat
  • Use repellent
  • Check for ticks daily
  • Know the symptoms and seek care promptly

29. 2. Environmental management

  • Ticks die quickly in sunny, dry areas
  • Landscape yard to create tick-safe zones
    • clear brush and leaf litter
    • wood chips or gravel between lawns and wooded
    • keep playground equipment away from yard edges and trees

From: Kirby Stafford, Tick Control Handbook, Connecticut Agricultural Experiment Station 30. 2. Environmental management

  • Properly timed, a single application of acaracide in late May or early June can reduce tick populations by 68-100%
  • Fungi that kill ticks also being evaluated

From: Kirby Stafford, Tick Control Handbook, Connecticut Agricultural Experiment Station 31. 3. Community prevention

  • Deer do not get Lyme disease but are an important source of the blood adult ticks need to reproduce
  • Interventions related to controlling deer movement, populations, or tick burdens best accomplished at the community level

32. 33. Thank You! The findings and conclusions in this report have not been formally disseminated by the Centers for Disease Control and Prevention and should not be construed to represent any agency determination or policy