Saturday, October 25, 2014
     

Viral Hemmorhagic Fever

Etiologic Agents:

  • Arenaviradae (lassa, junin, machupo, guanarito, and sabia), filoviradae (marburg and ebola), Bunyaviradae (congo-crimean hemmorhagic fever virus and hantaviruses) and Flaviradae (yellow fever and dengue) can all cause Viral Hemmorhagic Fever (VHF)

Epidemiology:

  • Highly infectious after aerosolization
  • Infectious dose can be as low as 1-10 organisms
  • Risk of person-to-person transmission depends on virus

Clinical:

  • Incubation period is 4 - 21 days, depending on virus
  • Clinical presentation would vary by viral agent; however, dominant clinical features of all are a consequence of microvascular damage and changes in vascular permeability. fever, myalgia, and prostration may evolve to shock, generalized mucous membrane hemmorhage, and neurologic, hematopoietic, or pulmonary involvement

Laboratory Diagnosis:

  • Viral isolation should be handled in a biosafety level 3 or 4 facility and may take 3 - 10 days
  • Elisa or reverse transcriptase PCR available for most V.H.F. viruses

Patient Isolation:

  • Isolation room with Contact Precautions

Treatment:

  • Ribavirin (30 mg/kg iv x 1, then 15 mg/kg iv q 6 h x 4 days, y.5 mg/kg iv q 8 x 6 days) may be helpful for congo-crimean hemmorhagic fever or arenaviruses

Prophylaxis:

  • Licensed vaccine available only for yellow fever