A virus of the genus Flavivirus (group B arbovirus) occurring particularly in Japan but probably widespread throughout Southeast Asia; the virus is normally present in humans, especially in children, as an inapparent infection, but may cause febrile response and sometimes encephalitis; it may cause encephalitis in horses and abortion in pigs; wild birds are probably the natural hosts and culicine mosquitoes the vectors.
Synonym: Russian autumn encephalitis virus.
(05 Mar 2000)