Epidemiology of Japanese encephalitis: past, present, and future prospects

Abstract

Japanese encephalitis (JE) is one of severe viral encephalitis that affects individuals in Asia, western Pacific countries, and northern Australia. Although 67,900 JE cases have been estimated among 24 JE epidemic countries annually, only 10,426 have been reported in 2011. With the establishment of JE surveillance and vaccine use in some countries, the JE incidence rate has decreased; however, serious outbreaks still occur. Understanding JE epidemics and identifying the circulating JE virus genotypes will improve JE prevention and control. This review summarizes the current epidemiology data in these countries.

Keywords: Japanese encephalitis; Japanese encephalitis virus; acute encephalitis syndrome.

Figure 1

Global distribution of Japanese encephalitis (JE) infection countries and risk areas. Notes: ■Japanese encephalitis risk countries that the epidemiological pattern of JE is epidemic; ■Japanese encephalitis risk countries that the epidemiological pattern of JE is endemic.