Lyme Disease

1
Lyme Disease

• April 29, 2003
• Madina Agenor
• Sogole Moin

2
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.

3
Distribution

• Mostly localized to states in the northeastern,
  mid-Atlantic, and north-central regions, and to
  several counties in northwestern California

http//www.cdc.gov/ncidod/dvbid/lyme/
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• 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

5
Causative Agent

• Borrelia burgdorferi sensu stricto
• Spirochete slender helical
• shaped bacteria
• Gram negative
• Motile
• Extracellular pathogen
• Aerobic or microaerophilic

http//www.cdc.gov/ncidod/dvbid/lyme/
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• .2um to 5um in width and 10 to 25 um in length
• Protoplasmic cylinder
• Cell membrane
• Outer membrane
• 7 to 11 flagella

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• 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

8

• 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

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• U.S. B. burgdorferi sensu stricto
• Europe B. burgdorferi sensu stricto, B. garinii,
  and B. afzelii
• Asia B. garinii and B. afzelii

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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

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• Two-year life cycle of tick
• Larval, nymphal and adult stages

http//www.cdc.gov/ncidod/dvbid/lyme

• Nymphal ticks are size of
• poppy seeds

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• 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

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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

http//www.cdc.gov/ncidod/dvbid/lyme/diagnosis.htm
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• 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

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• Post-Lyme disease syndrome
• Persistent disease after antibiotic treatment
• Controversial
• Some infected individuals show asymptomatic
  infection
• Some only manifest nonspecific symptoms

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Diagnosis

• Serologic data by IFA, ELISA and immmunoblotting
  techniques.
• Detect presence of IgM or IgG antibodies in
  patients 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

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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

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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

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• 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

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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

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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 15187(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
  Spring2(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
  Mar47(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/nci
  dod/dvbid/lyme/
• Zeus Scientific, Inc. IFA Assays Bacterial
  Diseases. http//www.zeusscientific.com/ifabact.h
  tml. 23 April 2003.