Lassa fever

Although the term nucleoside was once limited to the compounds in Table 28.2 and a few others, cunent use is more permissive. Pyrimidine derivatives of D-arabinose, for exfflnple, occur in the free state in certain sponges and are called spongonticleosides. The powerful antiviral drug ribavirin, used to treat hepatitis C and Lassa fever, is a synthetic nucleoside analog in which the base, rather than being a pyrimidine or purine, is a triazole. 

Lassa Fever W. Africa Rodent Aerosol, Fomites ... 

Drugs Available Prophylactic ribavirin may be effective for Crimean-Congo hemorrhagic fever, Lassa fever, and Rift Valley fever. 

Lassa Fever Aerosol Low to moderate High 10-14 days 1-4 weeks Unknown Relatively stable No Effective Experi- mental... 

Treatments with immune globulin vaccines are useful against Crimean Congo hemorrhagic fever, Rift Valley fever, Bolivian hemorrhagic fever, and Lassa fever Yellow fever vaccine is the only established and licensed vaccine for a hemorrhagic fever several others are under development... 

Although ribavirin monotherapy is ineffective against HCV, oral ribavirin in combination with inter-feron-a (Rebatron) is approved for this indication and is effective in patients resistant to interferon therapy alone. Intravenous ribavirin may be useful in the therapy of Hantaan virus infection, Crimean or Congo virus hemorrhagic fever, Lassa fever, and severe adenovirus infection. 

Intravenous ribavirin decreases mortality in patients with Lassa fever and other viral hemorrhagic fevers if started early. High concentrations inhibit West Nile virus in vitro, but clinical data are lacking. Clinical benefit has been reported in cases of severe measles pneumonitis and certain encephalitides, and continuous infusion of ribavirin has decreased virus shedding in several patients with severe lower respiratory tract influenza or parainfluenza infections. At steady state, cerebrospinal fluid levels are about 70% of those in plasma. 

Antiviral spectrum Ribavirin is used in treating infants and young children infected with severe RSV infections. [Note It is not indicated for use in adults.] Favorable responses of acute hepatitis A virus and influenza A and B infections have also been reported. Ribavirin may reduce the mortality and viremia of Lassa fever. 

Adverse effects Side effects reported for oral or parenteral use of ribavirin have included dose-dependent transient anemia in Lassa fever victims. Elevated bilirubin has been reported. The aerosol may be safer, although respiratory function in infants can deteriorate quickly after initiation of aerosol treatment and therefore, monitoring is essential. Because of teratogenic effects in experimental animals, ribavirin is contraindicated in pregnancy. 

Ribavirin Interference with viral messenger RNA Lassa fever, hantavirus (hemorrhagic fever renai syndrome), hepatitis C (in chronic cases in combination with interferon a) 30-60... 

First-line therapy for Lassa fever infection includes which of the following ... 

Centers for Disease Control and Prevention. (2004). Imported Lassa fever—New Jersey, 2004. MMWR Morbidity and Mortality Weekly Report, 53(38), 894-897. 

Not currently available, except for Lassa fever. Other vaccines are under development. 

Ribavirin for Lassa fever and possibly other arenavirus infections. Supportive therapy for other VHP infections. 

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