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    • Lyme Disease April 29, 2003 Madina Agenor Sogole Moin
    • Disease History
      • In the early 1900s, manifestation first reported in Europe
        • associated it with tick bites
      • In 1975, outbreak in Lyme, Connecticut
        • Believed to be juvenile rheumatoid arthritis
      • In 1982, spirochetes were identified in the midgut of the black-legged tick ( Ixodes scapularis ) and named Borrelia burgdorferi .
      • In 1984, Borrelia burgdorferi was isolated from the blood of patients with EM and from the rash lesion itself.
        • Determined etiologic agent
      • Today, it is the most common tick-borne infection in the U.S.
        • more than 16,000 infections each year.
    • Distribution
      • Mostly localized to states in the northeastern, mid-Atlantic, and north-central regions, and to several counties in northwestern California
      • In 1996-1999, the states with the highest reported number of Lyme disease cases were: New York, Connecticut, Pennsylvania, New Jersey, Wisconsin, Maryland and Rhode Island
      • Also reported in Europe, Asia and Australia
      • Where suburban and country residential dwellings encroach on wooded areas
      • Most common during late spring and summer
    • Causative Agent
      • Borrelia burgdorferi sensu stricto
      • Spirochete: slender helical
      • shaped bacteria
      • Gram negative
      • Motile
      • Extracellular pathogen
      • Aerobic or microaerophilic
      • .2um to 5um in width and 10 to 25 um in length
      • Protoplasmic cylinder
      • Cell membrane
      • Outer membrane
      • 7 to 11 flagella
      • Cell division after 12 to 24 hours of elongation
      • Optimal temperature is 33C
      • Incubation period of 3 to 32 days after infecting the human host through a tick bite
      • Genome: linear chromosome and numerous linear/circular plasmids
      • Plasmids encode key genes involved in virulence
      • B. burgdorferi discovered in 1982
      • Isolated and cultured from the tick Ixodes scapularis
      • Midgut contents of the tick removed and cultured on BSKII medium
      • Motile spirochetes isolated and observed by dark field microscopy
      • Spirochetes identified as B. burgdorferi
      • U.S.: B. burgdorferi sensu stricto
      • Europe: B. burgdorferi sensu stricto, B. garinii , and B. afzelii
      • Asia: B. garinii and B. afzelii
    • Methods of Transmission
      • Vector-borne disease
      • Vector is deer or black-legged tick ( Ixodes scapularis ) or by the western black-legged tick ( Ixodes pacificus) on the Pacific Coast.
      • Transmits B. burgdorferi while feeding on an uninfected host
        • the spirochetes are present in the midgut and migrate during blood feeding to the salivary glands, from which they are transmitted to the host via saliva.
      • B. burgdorferi cannot penetrate intact skin
      • Two-year life cycle of tick
        • Larval, nymphal and adult stages
      • Nymphal ticks are size of
      • poppy seeds
      • Reservoir for B. burgdoferi is deer
      • or white-footed mouse
      • Human contact can occur through pets
      • and outdoor activities in wooded areas
      • If tick is attached for less than 24 hours,
      • risk of acquiring Lyme disease is significantly reduced.
      • Once in the host, B. burgdorferi recognizes polysaccharides on the surface of mammalian cells
    • Symptoms
      • Symptoms of B. burgdorferi
      • Stage 1
        • Localized erythema migrans (EM)
        • Red macule/papule
        • Round lesion that measures 5cm to 15cm. 
      • Stage 2
        • Early disseminated infection
          • multiple secondary erythema migrans lesions
          • systemic non specific symptoms
        • Persistent or late infection
          • Symptoms of neurologic disease
          • Symptoms of musculoskeletal disease
          • Symptoms of cardiac disease
          • Chronic inflammatory eye disease
      • Stage 3
        • 6 months after primary skin lesion
          • Swelling and pain in large weight-bearing joints, especially in the knee.
          • Chronic arthritis
        • Years after infection, if left untreated :
          • Late neurological syndrome
      • Post-Lyme disease syndrome
        • Persistent disease after antibiotic treatment
        • Controversial
      • Some infected individuals show asymptomatic infection
      • Some only manifest nonspecific symptoms
    • Diagnosis
      • Serologic data by IFA, ELISA and immmunoblotting techniques.
        • Detect presence of IgM or IgG antibodies in patient’s serum against Borrelia burgdorferi
        • Tests are insensitive the first several weeks of infection
        • Western blot is more accurate and is used 6-12 weeks after infection to confirm results
      • Direct Isolation
        • Biopsies of the skin lesions may yield the organism in 50% or more of cases
    • Cure
      • Antibiotic therapy
      • Doxycycline and amoxicillin are used for two to four weeks in early cases
      • Doxycycline is also effective against human granulocytic ehrlichiosis
      • Cefuroxime axetil or erythromycin can be used for patients who are allergic to penicillin or who cannot take tetracyclines.
      • More developed cases, may require treatment with intravenous ceftriaxone or penicillin for 4 weeks or more
    • Prevention
      • Avoid tick habitats
      • Wear appropriate barrier clothing that follow personal protection procedures
      • Apply insect repellent containing DEET to skin
      • Apply permethrin to clothes
      • Perform regular body checks for ticks
      • Remove ticks promptly with tweezers and clean area with antiseptic
      • Education of the general public
      • Lyme disease vaccine: LYMErix
        • Recommended to 15-70 year olds living in endemic areas
        • Recommended to those who are at risk due to occupation
        • Only suggested to those who have a seasonal problem of infection greater than 1%
        • No longer commercially available since February 25, 2002
    • Control
      • Habitat modification for ticks
      • -Clear trees and brush
      •   Chemical control of tick populations
      • -Apply pesticides to residential properties
      • Habitat modification for deer and rodents
      • -Keep rodents and deer away from houses and gardens
      • Host management
      • -Deer feeding stations equipped with pesticide applicators
      • -Baited devices to kill ticks on rodents
    • Works Cited
      • Bacon, R.M., B.J. Biggerstaff, M.E. Schriefer ME, R.D. Gilmore Jr, M.T. Philipp, A.C. Steere, G.P. Wormser, A.R. Marques, B.J. Johnson. “Serodiagnosis of Lyme Disease by Kinetic Enzyme-Linked Immunosorbent Assay Using Recombinant VlsE1 or Peptide Antigens of Borrelia burgdorferi Compared with 2-Tiered Testing Using Whole-Cell Lysates.” Journal of Infectious Diseases . 2003 Apr 15;187(8):1187-99.
      • Benenson, Abram. Ed. Control of Communicable Diseases Manual . Washington, DC: American Public Health Association, 1995.
      • Crippa, M., O. Rais and L. Gern. “Investigations on the mode and dynamics of transmission and infectivity of Borrelia burgdorferi sensu stricto and Borrelia afzelii in Ixodes ricinus ticks.” Vector Borne Zoonotic Diseases . 2002 Spring;2(1):3-9.
      • Durham, Jerry D. and Felissa R. Lashley. Emerging Infectious Diseases: Trends and Issues . New York: Springer Publishing Co., 2002.
      • Parveen, N., M. Caimano, J.D. Radolf, J.M. Leong. “Adaptation of the Lyme disease spirochaete to the mammalian host environment results in enhanced glycosaminoglycan and host cell binding.” Molecular. Microbiology. 2003 Mar;47(5):1433-44.
      • Perry, Jerome, James Staley, Stephen Lory. Microbial Life . Sunderland, MA: Sinauer Associates, Publishers, 2002.
      • CDC Lyme Disease Home Page. http://www.cdc.gov/ncidod/dvbid/lyme/
      • Zeus Scientific, Inc. “IFA Assays – Bacterial Diseases”. http:// www.zeusscientific.com/ifabact.html . 23 April 2003.