Historical review and surveillance of Japanese encephalitis, Republic of Korea, 2002–2004

Abstract

Japanese encephalitis virus (JEV), transmitted by culicine mosquitoes, is endemic throughout much of South‐East Asia, extending to the Korean Peninsula. The zoonotic cycle is from large water birds to culicine mosquitoes, with swine as an amplifying host and man as an incidental host. Culex tritaeniorhynchus, the primary JEV vector in the Republic of Korea, populations peak in late August through to early September when most cases of Japanese encephalitis (JE) are reported. Cx. tritaeniorhynchus were observed near the Demilitarized Zone in each of the years that mosquitoes were assayed for JEV. Each year that vector mosquitoes were assayed for JEV, minimum field infection rates (number of JEV positive mosquites/1000 Cx. tritaeniorhynchus assayed) ranged from 0.31 to 3.27. The epidemiology of JE has been recorded in Korea for more than half a century, from 1949 to 2005. During a major epidemic in 1949, there were 5616 cases and 2729 deaths reported, with levels persisting near epidemic levels of 1000 cases annually thereafter until 1969. Following the introduction and government mandated mass immunization in 1971, JE decreased dramatically. Since 1984, 0–6 cases of JE have been reported each year. However, continued evidence of mosquitoes positive for JEV indicates that JE continues to be a civilian and military health threat to immunocompromised persons in Korea, as well as non‐immune US soldiers, civilians and their family members.

Potential chemotherapeutic targets for Japanese encephalitis: current status of antiviral drug development and future challenges

“…The improved vaccine was introduced into the routine immunization program in Japan in 1967, when > 1000 cases per year occurred, and the number of reported cases has since decreased markedly, with < 10 cases reported annually since 1992 [78]. Similar trends have been observed in China [79], Korea [80,81], Malaysia [82], Nepal [83], Sri Lanka [84], Taiwan [85], Thailand [86,87] and Vietnam [88]. These observations clearly indicate that JE is a vaccinepreventable infectious disease.…”

Distribution and Mosquito Hosts of Chaoyang Virus, a Newly Reported Flavivirus From the Republic of Korea, 2008–2011

“…Viral complete coding sequences were determined and found to contain a high sequence homology to other mosquito-borne ßa-viviruses, that is, Sepik virus and dengue virus 2 (Wang et al 2009, Liu et al 2011. As part of the U.S. Army mosquito surveillance program in the Republic of Korea (ROK), an unknown ßavivirus was isolated from a pool of Aedes vexans nipponii Theobald (ROK144) collected in June 2003 at Camp Greaves (closed in 2006) that was located Ϸ3 km from the southern boundary of the demilitarized zone (DMZ) that separates Democratic PeopleÕs Republic of Korea (North Korea) from the ROK (South Korea) (Kim et al 2007a). Subsequently, the isolate (ROK144) was determined to be the same as CHAOV Þrst described from China in 2009.…”

Seasonal prevalence and species composition of mosquitoes and chigger mites collected from Daegu, Gunwi and Sangju in South Korea, 2014

“…Studies on the seasonal prevalence of mosquitoes in Korea have begun with the re-emergence of Plasmodium vivax which reported to have already disappeared near the Gyeonggi province in 1993 (Kim, Chong, Collier, Lee, & Klein, 2007a, Kim, Chong, Collier, & Klein, 2009a, Kim, Chong, Nunn, McNemee, & Klein, 2009b, Kim, Friendly, et al 2003a, Kim et al 1997, Kim et al 1999, Kim, Lee, et al 2003b, Kim et al 2000, Kim, Turell, et al 2007b, Kim, Chong, Collier, & Klein, 2009a, Lee et al 2009, Shim et al 2010.…”