Emergency Preparedness

Kern Medical Bioterrorism Response Guide Section 2-C-2 – Viral Hemorrhagic Fever

not evaluated, dopamine would seem to be the agent of choice for patients with shock who are unresponsive to fluid replacement. Adrenergic vasoconstricting agents, although not clinically evaluated, may be useful in the treatment of profound hypotension. Vasodilators have not been clinically evaluated. Pharmacological doses of corticosteroids (e.g., methylprednisolone 30 mg/kg) provide another possible but untested therapeutic modality in treating shock. Specific Antiviral Therapy The investigational antiviral drug ribavirin is available by compassionate use protocols for treatment of Lassa fever, HFRS, Congo-Crimean HF, and Rift Valley fever. Separate Phase III efficacy trials have indicated that parenteral ribavirin reduces morbidity in HFRS and lowers both morbidity and mortality of Lassa fever. In an HFRS field trail, treatment was effective if started during the first four days of fever and continued for seven days. A compassionate-use protocol, utilizing intravenous ribavirin as a treatment for Lassa fever, is sponsored by the CDC. Doses are slightly different and continued for a 10-day course. The only significant side effect of ribavirin is a modest anemia due to a reversible inhibition of erythropoiesis and mild hemolysis. Ribavirin is teratogenic in laboratory animals and the potential benefits must be weighed against the potential risks in pregnant women with serious illness due to one of the VHF. Safety in infants and children has not been established. Ribavirin has poor in vitro and in vivo activity against filoviruses (Ebola and Marburg) and flaviviruses (dengue and yellow fever). Isolation The viruses that cause hemorrhagic fever pose special challenges for hospital ICP. With the exception of dengue (virus present, but no secondary transmission occurs) and hantavirus (virus not present in the blood or body fluids at the time of clinical illness), VHF patients generally have significant quantities of virus in blood, excretions and secretions. Health care workers must handle all sharps with extreme safety to avoid percutaneous exposure. Lassa, Congo-Crimean HF, Ebola and Marburg viruses may be prone to aerosol nosocomial transmission. Secondary infections among medical personnel who were not parenterally exposed (but still might have had blood contact with non-intact skin or mucosal membranes) are well documented in countries where these diseases occur naturally.

1