Phylogeographic analysis of the migration of Japanese encephalitis virus in Asia

Abstract

Japanese encephalitis virus (JEV) is one of the zoonotic arboviruses, and causes encephalitis in humans. Our phylogenetic analysis revealed that some phylogenetic subclusers were distributed as widely as continental Asia to Japan (subclusters 1-A-1, 1-A-2, 1-A-3, 1-A-5, 3-A-1, 3-A-2, 3-B-1 and 3-D). However, two subclusters were only isolated in Japan (1-A-6 and 1-A-7). These data suggest that multiple populations of JEV have migrated from southeast Asia and continental east Asia to Japan and, in Japan, JEV can overwinter and settle. In this article, we aim to explain the ecological factors related to the overseas expansion, migration and overwintering of JEV.