Viral Hemorrhagic Fevers

Etiologic Agents

Arenaviradae (Lassa, Junin, Machupo, Guanarito, and Sabia), Filoviradae (Marburg and Ebola), Bunyaviradae (Congo-Crimean hemorrhagic fever virus and hantaviruses)and Flaviradae (yellow fever and Dengue) can all cause viral hemorrhagic 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 VHF viruses

Patient Isolation

Isolation room with contact precautions.

Treatment

Ribavirin (30 mg/kg IV × 1, then 15 mg/kg IV q 6 h × 4 days, 7.5 mg/kg IV q 8 × 6 days) may be helpful for Congo-Crimean hemorrhagic fever or arenaviruses

Prophylaxis

Licensed vaccine available only for yellow fever