Hemorrhagic fever with renal syndrome in Korea.

Several clinical variants of hemorrhagic fever with renal syndrome (HFRS) are caused by Hantaan and related viruses. Since 1951, 500-900 patients with HFRS have been hospitalized annually in Korea. Although HFRS is associated primarily with rural areas, it is now being recognized as an urban problem and a particular hazard to laboratory staff using rodents for research. Recently, epidemic outbreaks of leptospirosis and scrub typhus have occurred during the HFRS season, leading to confusion in diagnosis. Serologic diagnosis of HFRS is based on the demonstration of IgM antibodies to Hantaviruses by the indirect fluorescent antibody technique or enzyme-linked immunosorbent assay. The specific Hantavirus causing infection can be identified on the basis of titers of plaque-reduction neutralizing antibody. Results of studies with monoclonal antibodies suggest that viral subtypes exist for each Hantaviral serotype presently recognized. While infection with Hantaviruses is known to be a problem of worldwide dimensions, present evidence indicates that it occurs over a wider area than previously recognized. Vertical transmission of Hantaan virus in a pregnant woman has been documented.