Background

Hemorrhagic fever with renal syndrome (HFRS) is a good example of an important re-emerging viral disease with high fatality because it is an old-disease existing for more than 100 years in the world.1 However, it is quite new to Western Medicine because hantavirus infection attracted the attention of the world during the Korean War and last year when a deadly mysterious lungswelling illness occurred in the U.S.A. The history of diseases caused by hantaviruses is very interesting and useful to understand rodent-borne hantavirus infections because it has many episodes among soldiers in the past wars with different names in different parts of the world as shown in Table 1. Large outbreaks of epidemic nephritis and hemorrhagic fever with renal syndrome occurred among soldiers during the American Civil War, the First World War, the Second World War and the Korean War, and the number of victims was more than several thousands respectively.2 The discovery of the new virus causing Korean hemorrhagic fever (KHF) by Lee et al3,4 now called Hantaan virus, launched a new era in the study of hemorrhagic fever with renal syndrome throughout the world. HFRS is an acute infectious viral disease characterized by an abrupt high fever, various hemorrhagic manifestations, a flushed face, transient renal and hepati