Ribavirin, a broad-spectrum
antiviral drug, is active against hemorrhagic
fever viruses (with the exception of Ebola virus) in cell culture systems. In model
infections with arenaviruses in guinea pigs and monkeys,
ribavirin has demonstrated both prophylactic and therapeutic efficacy. In therapeutic studies it has not prevented late-onset neurologic disease. In human cases of
Lassa fever, it significantly reduces mortality when administered before day 7 of illness to persons at high risk. In rodents and monkeys infected with Rift Valley fever virus,
ribavirin therapy resulted in reduced mortality; prophylactic administration to volunteers infected with
sandfly fever virus, Sicilian strain, prevented development of illness.
Ribavirin increased the number of survivors and the mean time to death in suckling mice infected with Crimean-Congo hemorrhagic fever virus and in suckling mice infected with Hantaan virus. In the People's Republic of China,
ribavirin significantly reduced mortality in patients with
hemorrhagic fever with renal syndrome.
Ribavirin has not been effective in animal models of filoviral and flaviviral
infections. The only important adverse effect of
ribavirin in humans is manageable, reversible
anemia.