Hemorrhagic Fever with Renal Syndrome (HFRS) is caused by viruses in the genus Hantavirus of the family Bunyaviridae. There are four known Hantavirus that cause HFRS: Hantaan, Seoul, Puumala and Dobrava viruses. HFRS is acquired by contact with chronically infected rodent hosts, most commonly from inhalation of infected rodent excreta. Hemorrhagic fever with renal syndrome is characterized clinically by the triad of fever, hemorrhage and renal insufficiency. HFRS typically consists of five consecutive but frequently overlapping clinical phases: febrile, hypotensive, oliguric, diuretic and convalescent. DoD operations have resulted in the deployment of personnel in Europe and Southeast Asia, areas endemic for HFRS, a viral hemorrhagic fever. Early initiation of therapy with intravenous Ribavirin has been shown to be an effective treatment for HFRS. It is therefore important to initiate therapy based on a clinical diagnosis consistent with viral hemorrhagic fever and with an epidemiological history for risk of exposure to the hantavirus. Ribavirin is a nucleoside (guanosine) analog with activity against a wide variety ribonucleic acid and deoxyribonucleic acid viruses. Mechanism of action is not fully defined. The mechanism may be related to alteration of cellular nucleotide pools and of viral messenger RNA formation, but recent data suggest the mechanism of Ribavirin in HFRS may be to serve as a RNA virus mutagen resulting in an "extinction catastrophe" error, as a result of incorporation in the viral RNA genome.

Ribavirin is licensed in the United States in aerosol form for the treatment of severe lower respiratory tract infection in children and in the oral formulation in combination with recombinant interferon alpha for the treatment of chronic hepatitis C infection. The intravenous formulation of ribavirin in not licensed in the United States. IV Ribavirin for the treatment of HFRS is used under IND 16,666.

This is a Phase 2, open-label study of the safety of IV Ribavirin treatment in individuals with Hemorrhagic Fever with Renal Syndrome (HFRS) admitted to the 121st Combat Support Hospital, Seoul, Republic of Korea. The study will also monitor morbidity and mortality of subjects with HFRS who are treated with IV Ribavirin. The study population will include all subjects with a probable or suspected clinical diagnosis of HFRS, at least 18 years of age (age 17 if active military) but not greater than 65 years of age. The Investigators intend to treat all individuals who present with a tentative diagnosis of HFRS (and within 7 days of onset of illness) and meet entry criteria with a 7 day course of IV Ribavirin and a 28-60 day follow up period after first dose of Ribavirin. In addition to treatment with Ribavirin, all subjects will be given standard supportive and symptomatic care as determined by the clinical judgment of attending physicians or consultants who manage the subject's care at the 121 CSH. Up to 50 subjects could potentially be enrolled in a five year time period with an expected accrual of 0-5 subjects per year, but the number may be higher (10 to 20 persons in a year) if an HFRS outbreak should occur. Specific inclusion/exclusion/relative exclusion criteria are a part of the protocol. Safety procedures required during 7 days of treatment include continuous cardiac monitoring, daily lab work, physical exams and vital signs.