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Lyme MCW- Lyme Disease


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An informative presentation on Lyme disease prepared by Please visit our website for more information.

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Lyme MCW- Lyme Disease

  2. 2. Life Cycle & Transmission • Causative agent: Borrelia burgdorferi • Reservoir host in U.S.: Ixodes scapularis • Ixodes ticks have a 2-year life cycle • Once a tick is infected, it remains infected for the rest of its life & can transmit bacteria to other hosts while feeding at a later life stage • Nymphs more likely to feed on humans than adult ticks • Ticks often found in hard-to-see areas (scalp, armpits, groin, etc.) • Ticks must remain attached for 24-48 hours before transmission of bacteria
  3. 3. Epidemiology • First recognized in the U.S. in 1975 in Lyme, Connecticut • About 300,000 new cases occur annually in the U.S., mostly in the Northeast & upper Midwest (CDC) • Lyme disease is the highest reported vector-borne disease in Wisconsin • Risk of exposure is greatest in the woods and in edge area between lawns and woods, especially in late spring/early summer • Campers, hikers, and outdoor workers are most likely to be infected
  4. 4. Epidemiology Geographic expansion of Ixodes scapularis
  5. 5. Clinical Features • 3 stages of Lyme disease • Early localized Lyme disease is marked by erythema migrans; may develop a "bullseye" appearance as the rash enlarges; occurs in 70-80% of infected persons (CDC). • Early disseminated symptoms also include fatigue, chills and fever, headache, muscle and joint pain, swollen lymph nodes, facial palsy, and irregular heart beat or heart palpitations (Lyme carditis). • Late stage symptoms include arthritis, numbness, nerve pain or paralysis, meningitis, and problems with memory or concentration. • Patients usually do not have all these symptoms, some may not have any symptoms of infection at all.
  6. 6. Clinical Features •Different species of Borrelia bacteria can lead to different clinical outcomes of Lyme disease • B. burgdorferi is particularly arthritogenic • B. afzelii primarily causes skin infections (acrodermatitis chronica atrophicans) • B. garinii is especially neurotropic • B. afzelii and B. garinii are only found in Europe and Asia •Different strains of the same species can also have different clinical outcomes, which may explain regional variation
  7. 7. Diagnosis •It can take 4-6 weeks after infection for the body to produce measurable amounts of antibodies • Patients who were recently infected may test negative even though they are infected (false negative) • Some patients may actually test positive for IgM without having an active infection (false positive) • Patients who have been infected longer than 6-8 weeks and have arthritis will nearly always test positive
  8. 8. Treatment & Public Health Costs •Positive diagnosis can be treated with antibiotics, given by mouth or intravenously •Persistent symptoms may require an additional course of antibiotic treatment •Treatments not recommended (Steere et al. 2016) ◦ Long-term antibiotic therapy ◦ Combinations of antibiotics ◦ Hyperbaric oxygen or ozone therapy ◦ Radiation-based therapies ◦ Fever therapy ◦ Intravenous immunoglobulin ◦ Stem cell transplants •Misdiagnosis & inappropriate treatment increase the cost of Lyme disease
  9. 9. Natural History of Lyme Disease •Without antibiotic treatment, the symptoms of Lyme disease generally resolve within weeks to months, but infection can last for years •Spirochetes might survive in localized niches in untreated patients for several more years (Steere et al. 2016) •Episodic symptoms may be a result of Borrelia escaping from protected niches and can lead to worsening symptoms over time • Around 50-60% of untreated patients in the U.S. will develop arthritis 6-18 months later •Antibiotic therapy for 1 month is usually effective at clearing infection, although infection can be cleared over time by the immune system without antibiotics
  10. 10. Post-Treatment Lyme Disease Symptoms (PTLDS) •Even after appropriate treatment and spirochetal killing, symptoms of Lyme disease can persist •Patients • Do not have any evidence of an active infection • Ongoing symptoms are thought to be related to unresolved immune responses to prior infection •Subjective symptoms following an infection are not unique to Lyme •Why does PTLDS develop? ◦ Patients with a longer duration of symptoms before treatment tend to have a higher risk ◦ Polymorphism in TLR1 is associated with persistent arthritis after antibiotic therapy (Strle et al. 2012)
  11. 11. “Chronic Lyme Disease” Controversy •Clinicians & scientists generally do not consider “chronic Lyme” an appropriate diagnosis •CLD diagnosis often based on subjective symptoms, including myalgias, arthralgias, headache, fatigue, irritability, and cognitive dysfunction (Lantos 2015) •Insurance companies do not cover long-term antibiotic therapy for “chronic Lyme” treatment • Treatment is not effective in resolving symptoms •Alternative “chronic Lyme” diagnosis results in patients not being treated for other potential diseases that are causing symptoms
  12. 12. Prevention • Avoid tick-infested areas • Use insect repellent containing DEET • Bathe or shower and check for ticks after being outside • Wear protective clothing & put clothes in a hot dryer for 10 minutes to kill any ticks attached • Use “tick-safe landscaping” • Apply pesticides to yards • Discourage tick-infested deer by removing plants that attract deer
  13. 13. Additional Resources Follow us @LymeMCW and visit us at Lyme MCW is an educational and outreach program founded by the Lochhead Lab at the Medical College of Wisconsin. Our goal is to serve as a trusted source of information on Lyme & other tick- borne diseases endemic to the state of Wisconsin.
  14. 14. References Lantos, Paul M. “Chronic Lyme Disease.” Infectious disease clinics of North America 29.2 (2015): pp. 325–340. PMC. Web. Accessed 23 Oct 2018. “Lyme Disease.” Centers for Disease Control and Prevention. 15 Oct 2018. Accessed 17 Oct 2018. “Lyme Disease.” Wisconsin Department of Health Services. 7 Aug 2018. lyme/index.htm. Accessed 17 Oct 2018. Steere, Allen, et al. 15 Dec 2016. “Lyme borreliosis.” Nature Reviews: Disease Primers, vol. 2, pp. 1-18, Accessed 17 Oct 2018. Weaver, Jane. 16 July 2013. “More people search for health online.” NBC, people-search-health-online/#.W8d15fZRfIU. Accessed 17 Oct 2018.