Epidemic Encephalitis in the Far East

Abstract

I. Introduction It is the main purpose of this paper to present a summary of the existing knowledge of the epidemic encephalitides occurring in the Far East. These diseases are relatively unfamiliar to the majority of American physicians. Since the chances of their being encountered in portions of the eastern Asiatic continent seem likely, and, since the possibility that they may be introduced into the United States must be considered, it was thought that a description of their epidemiology, clinical manifestations, and diagnosis would be of interest. Two types of acute encephalitis caused by filterable viruses are endemic in the Far East; these are Japanese B encephalitis and Russian spring-summer encephalitis. Most of our present knowledge regarding Japanese B encephalitis dates from 1928 when a comprehensive paper by Kaneko and Aoki appeared (1), in which these authors concluded that the acute epidemic encephalitis occurring in Japan in the late summer and autumn was a distinct clinical entity and was to be differentiated from encephalitis lethargica (von Economo's disease).