Epidemiology and epizootiology of hantavirus infection in Japan.

Hantaviruses cause two severe human diseases: hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). Various rodent species act as animal reservoirs for hantavirus. In Japan, urban rat- (Rattus norvegicus) and laboratory rat-derived human infections were reported during the 1960s and 1970s-1984, respectively. Although no human cases of infection have been reported since 1984, infected urban rats have been found throughout Japan, and infected grey red-backed voles (Clethrionomys rufocanus) have been identified in Hokkaido. These carriers can be considered to be potential sources of human infection. This review examines the epidemiology and epizootiology of this important zoonosis in Japan.