Ehrlichiosis

Revision as of 03:36, 10 November 2013 by JCMiller (talk | contribs) (Ehrlichiosis)
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Background

  • Spread by the Lonestar tick (Amblyomma americanum)
    • Eastern seaboard from Florida to Maine and as far west as Iowa and Texas
    • People often unaware they are bitten
  • Case fatality rate is approximately 1.8%
    • More severe disease in immunocompromized patients (HIV, Elderly, Asplenic)

Symptoms

  • Fever, chills, headache, malaise, myalgias, nausea, vomiting, diarrhea, conjunctival injection
    • Up to 60% of children may have a rash (30% of adults)

Diagnosis

  • Obligate intracellular organism
    • Peripheral blood smear shows intracellular parasites only 20% of time
  • PCR
    • Most sensitive in first week of illness
  • Indirect Immunoflorescence Assay
    • Gold Standard
    • Negative 85% of time in first 7 days of illness
    • Compare 2 samples drawn at different times
      • 4 fold increase in titers of second draw is positive
  • Enzyme Immunoassay
    • Qualitative tests, not quantitative

Treatment

  • Doxycycline
    • 100mg BID (Adults)
    • 2.2mg/kg BID (children)

Sources

  • Wikipedia
  • cdc.gov/parastites/ehrlichiosis
  • uptodate.com