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