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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. * For Best Viewing: Open in Slide Show Mode Click on icon or From the View menu, select the Slide Show option * To help you as you prepare a talk, we have included the relevant text from ITC in the notes pages of each slide
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. in the clinic Lyme Disease
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. Terms of Use The In the Clinic ® slide sets are owned and copyrighted by the American College of Physicians (ACP). All text, graphics, trademarks, and other intellectual property incorporated into the slide sets remain the sole and exclusive property of ACP. The slide sets may be used only by the person who downloads or purchases them and only for the purpose of presenting them during not-for- profit educational activities. Users may incorporate the entire slide set or selected individual slides into their own teaching presentations but may not alter the content of the slides in any way or remove the ACP copyright notice. Users may make print copies for use as hand-outs for the audience the user is personally addressing but may not otherwise reproduce or distribute the slides by any means or media, including but not limited to sending them as e-mail attachments, posting them on Internet or Intranet sites, publishing them in meeting proceedings, or making them available for sale or distribution in any unauthorized form, without the express written permission of the ACP. Unauthorized use of the In the Clinic slide sets constitutes copyright infringement.
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. Who is at risk for Lyme disease? Anyone exposed to Ixodes ticks infected with Borrelia burgdorferi Also called “deer ticks” or “blacklegged ticks” Endemic: Northeastern, upper Midwestern regions; also N. California, N. Europe, parts of E. Asia Found in areas with animals they feed on Birds, small mammals: immature larval & nymphal ticks Deer: adult ticks In woods, tall brush or grass, leaves, wood piles Most common vector-borne disease in U.S.
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. What protective clothing can be worn to prevent tick bites? Limit access to exposed skin Tuck long pants into socks Wear long-sleeved shirt, hat Wear light-colored clothes Easier to spot crawling ticks Wear clothing impregnated with acaricide permethrin Alternately, spray permethrin on clothing Use insect repellants containing DEET DEET more effective than picaridin or IR3535
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. How should ticks be removed to reduce the chance of infection? Unattached ticks Can’t transmit disease if unattached: Just brush them off Attached ticks With tweezers or fingers: grasp at attachment site & tug gently, constantly Mouthparts will release, allowing clean removal in 1-2min If tick decapitated or mouthparts left in skin don’t worry: will shed from skin naturally Avoid other removal methods can lead to injury Takes 24-48h for B. burgdorferi to move tick to host Nightly “tick check” reduces disease transmission Bathing ≤2h of exposure may also reduce transmission
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. Should antibiotic therapy be given after a tick bite to prevent infection? Prophylaxis may be beneficial Amoxicillin or doxycycline Risks: medication side effects (nausea, vomiting) IDSA: use single-dose doxycycline if all criteria met: Tick is Ixodes adult or nymph Attached ≥36h Prophylaxis can be provided within 72h of tick removal Local rate of B. burgdorferi infection in ticks: >20%
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. Is it possible to acquire Lyme disease more than once? Perhaps: If treated early in course of illness Antibodies expressed early provide only strain-specific protection Short-lived immunity possible: EM incidence reduced in first year after Lyme disease episode Unlikely: If late-stage manifestations occur Signals broad antibody response to multiple antigens If frequent tick bites: Immune response may develop If itching occurs at bite site: B. burgdorferi less likely Reason unclear: ? result of early recognition and removal or local immune response to the bite
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. Is there a vaccine for Lyme disease? Human vaccine previously approved Utilized outer surface protein A (OspA) of B. burgdorferi as antigen Withdrawn from U.S. market in 2002, due to low sales OspA vaccine remains available for dogs
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. CLINICAL BOTTOM LINE: Prevention… Mainstay of prevention: avoidance Disease transmission by exposure to infected Ixodes tick To decrease transmission Use repellants, insecticides Perform nightly tick checks Wear long sleeve tops and pants Avoid tick habitats Remove any attached ticks Using tweezers or fingers, grasp at attachment site and tug gently until mouthparts release
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. What symptoms and signs should prompt investigation for Lyme disease? Fever Early disease; low predictive value because nonspecific Fatigue and/or malaise, headache At any stage of disease; low predictive value bc nonspecific Headache: ? meningitis Arthralgia Early disseminated infection or late disease with joint involvement Myalgia Indicative of acute disease but nonspecific Mono-/ oligoarticular inflammatory arthritis Disseminated or late disease Early antibiotic Rx reduces progression to arthritis
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. Erythema migrans In endemic areas, highly specific, may be mimicked by tick- associated rash Acute, localized disease (if multiple lesions indicate acute, disseminated disease) Note: Hx of witnessed tick bite not required Carditis (acute onset, AV conduction defects) Acute, disseminated disease Acute neurologic involvement (cranial neuropathy, meningitis, radiculoneuropathy) Acute neurologic dissemination More specific if Hx of EM Bilateral 7th nerve palsy more specific Peripheral neuropathy, encephalomyelitis, encephalopathy (rare) Late neurologic disease, but nonspecific
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. What other diseases should be considered in a patient who becomes ill after a tick bite? Co-infection: B. burgdorferi, A. phagocytophilum, B. microti Ticks may be simultaneously infected A. phagocytophilum + B. microti: transmission requires less time for tick attachment than B. burgdorferi A. phagocytophilum + B. burgdorferi or B. microti: may worsen initial presentation, but not long-term outcomes Infection with A. phagocytophilum or B. microti Febrile illness, w/o many other distinguishing symptoms A. phagocytophilum can cause early leucopenia + hepatitis
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. Southern tick-associated rash illness (STARI) Hard to distinguish from Lyme disease w/o identifying tick Rash similar to EM + fatigue, headache, muscle & joint pain, but no reported cardiac, joint, CNS involvement Associated with Amblyomma americanum ticks, common in southern U.S. & range expanding to Midwest, NE U.S. Infection with Ehrlichia New species found in Wisconsin and Minnesota Fever, headache, fatigue, muscle aches, rash
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. Cellulitis Urticaria Rocky Mountain spotted fever Cutaneous fungal infections Local reaction to tick bites Febrile viral illnesses Facial nerve palsy Viral meningitis Heart block Inflammatory arthritis Peripheral neuropathy Radiculoneuropathy Encephalomyelitis Differential diagnosis
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. What diagnostic tests should be done to confirm tick-borne diseases? Don’t test… Patients in endemic areas with tick exposure and EM (treat with appropriate antibiotics) Patients in endemic areas w/o tick exposure or with nonspecific symptoms (high incidence false-positives) When testing appropriate: Use 2-step approach 1. Screen initially with ELISA 2. If positive, use supplemental Western blot test Both tests can identify either IgM or IgG antibodies IgM response occurs in 1-2 weeks; IgG in 2-4 weeks In first 2 weeks: sensitivity suboptimal for IgM or IgG testing with ELISA and Western blot
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. C6 antibody test: newer, first-step ELISA Peptide from constant region B. burgdorferi protein (VlsE) Sensitivity equals IgM ELISA tests w/ improved specificity But specificity <2-step testing (98.4% vs. 99.5%) Recommended as a first step in 2-step strategy Area with high rates B. microti & A. phagocytophilum infection Test for co-infection B. microti: use routine blood parasite smear, serologic testing, or PCR testing PCR may remain positive even once asymptomatic (doesn’t necessarily indicate need for Rx) A. phagocytophilum: use blood smears (poor sensitivity) Human granulocytic anaplasmosis (ehrlichiosis): use serologic or PCR testing
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. What are the major complications of Lyme disease? EM: >90% prevalence Neurologic symptoms: 10%–20% (esp facial palsy) Cardiac involvement: 4%–10% Arthritis: ≈10% (less common now: earlier detection) All major manifestations typically resolve over time Nerve palsies and radiculopathy may persist Antibiotic Rx speeds resolution of some symptoms Rx in early stages generally = minimal sequelae
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. Is there a role for antibody screening to detect previous infection in asymptomatic persons? Don’t screen asymptomatic people in endemic areas Would yield high # of false-positive results ? Treat asymptomatic seropositive patients Expert opinion divided No studies support routine Rx Since perhaps >50% untreated patients develop arthritis, some experts recommend treatment Others believe # of asymptomatic seropositive patients who progress to clinical disease is much less
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. CLINICAL BOTTOM LINE: Diagnosis… In patients with manifestations other than EM: Diagnosis of Lyme disease depends on serologic testing More reliable for later-stage disease Lower sensitivity in early disease Use two-step testing Increases the specificity but may cause a slight decline in sensitivity Serologic results + clinical and epidemiologic data (i.e., prior probability of disease): increases/decreases likelihood a patient has Lyme disease
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. What antibiotic treatment should be given? Doxycycline Best bioavailability and CNS penetration Active vs. human granulocytic anaplasmosis Extended regimen for early disseminated disease manifestations (mild carditis, isolated facial nerve palsy) Amoxicillin (well-tolerated during pregnancy) Cefuroxime axetil (FDA approved for Lyme disease) Erythromycin (tolerated in penicillin allergy) Azithromycin Ceftriaxone (IV 1x/d for higher degree heart block, meningitis) Cefotaxime (no risk for biliary tract disease) Penicillin G (narrow spectrum) Efficacy equal: penicillins, cephalosporins, tetracyclines… but macrolides less efficacious
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. When should a patient with suspected or confirmed Lyme disease be admitted to the hospital? High-degree heart block To manage condition Meningitis or arthritis To establish Dx, determine if Lyme disease is cause Parenteral therapy Hospitalization often used to initiate Rx (not required)
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. How should cardiac complications of Lyme disease be treated? AV conduction delays Range: first-degree to complete heart block Most cases resolve spontaneously, even w/o Rx Administer antibiotics as soon as Dx established If Dx delayed and suspicion high: start antibiotic Rx before serologic testing available If second- or third-degree heart block May need temporary pacing device Patients typically admitted to hospital for IV treatment Once block resolved, switch to oral to complete Rx course
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. How should the neurologic complications of Lyme disease be treated? Facial palsy Use oral antibiotics: isolated peripheral nerve facial palsy Use parenteral antibiotics: central facial nerve palsy No steroids (don’t improve natural Hx Lyme facial palsy) Meningitis and severe radiculoneuritis (with/ without meningitis) and late neurologic complications (encephalomyelitis, radiculitis) Use parenteral antibiotics for 14–28 days Meningitis usually mild, self-limited (even without Rx) In Europe, oral doxycyline used for early Lyme disease neurologic complications, including meningitis Studies show noninferiority to IV penicillin or ceftriaxone
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. What is “chronic Lyme disease,” and how should it be treated? Continuation of symptoms after antibiotic Rx Is chronic Lyme disease legitimate clinical entity? Some manifestations of disease can persist Arthritis, neuropathy, radiculopathy Mechanism: ? damage from inflammatory response, persistent low-level infection, or autoimmune response Fatigue commonly persists up to 1 year Some patients report symptoms similar to fibromyalgia or chronic fatigue syndrome persist for many years Treatment Extended antibiotics don’t reduce such symptoms Arthritis: may respond to anti-inflammatory or immuno- modulatory agents (methotrexate, TNF inhibitors)
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. What other tools are available to help clinicians manage Lyme disease? CDC Up-to-date information on prevention, Dx, and Rx State-by-state statistics for transmission: www.CDC.gov/lyme www.CDC.gov/lyme Info on patient management, including instructions on tick removal, and fact sheets for patients Lyme Disease Foundation (www.ALDF.com)www.ALDF.com Connecticut handbook: management of tick exposure risk for homeowners www.ct.gov/caes/lib/caes/documents/publications/bulletins /b1010.pdf www.ct.gov/caes/lib/caes/documents/publications/bulletins /b1010.pdf
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© Copyright Annals of Internal Medicine, 2012 Ann Int Med. 157 (3): ITC2-1. CLINICAL BOTTOM LINE: Treatment… Symptoms resolve in most patients Even without antibiotic therapy Antibiotic therapy is recommended Hastens symptom resolution, prevents late sequelae Oral antibiotics: first-line therapy Parenteral therapy: if severe cardiac & neurologic symptoms present
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