Young June Choe1, Anne-Frieda Taurel2, Joshua Nealon2, Han Seok Seo1, Hee Soo Kim3. 1. Medical Affairs, Sanofi Pasteur Korea, Seoul, Republic of Korea. 2. Health Economics and Outcome Research, Sanofi Pasteur Asia & JPAC Region, Singapore. 3. Medical Affairs, Sanofi Pasteur Korea, Seoul, Republic of Korea. Electronic address: heesoo.kim@sanofi.com.
Abstract
BACKGROUND: Countries with strong vaccination programmes, including the Republic of Korea, have experienced changes in the epidemiology of Japanese encephalitis (JE), with an increase in cases seen among adults. However, the reasons for this increase are not clearly understood. This study describes the change in age-specific JE virus (JEV) seroprevalence over time in Korea, with a view to understanding this transition. METHODS: A search of Embase, MEDLINE, PubMed, KoreaMed, Korea Education and Research Information Service, National Library of Korea, and the Seoul National University Medical Library was conducted using the keywords 'Japanese encephalitis' combined with 'Korea', 'seroprevalence', 'seropositivity', 'seroepidemiology', 'serosurvey', 'immunity', and 'antibody'. RESULTS: Eighteen studies published between 1946 and 2012 were retrieved. In 1946, seropositivity was 51% in the 1-10 years age group, 79% in those aged 11-20 years, and 94% in those ≥61 years of age. In the 1970s, seropositivity in children and adolescents was low (10-59%); seropositivity in this group increased to 90-92% in 1984-1985, and increased further to 98% in 2012. Seropositivity among adults aged 41-50 years and 51-60 years in the 2010s ranged between 83.1% and 97.9% and between 77.5% and 98.3%, respectively. CONCLUSIONS: The implementation of the universal JE vaccination programme in the 1980s has increased the seroprevalence of JEV in Korea, especially in children who are targeted for vaccination.
BACKGROUND: Countries with strong vaccination programmes, including the Republic of Korea, have experienced changes in the epidemiology of Japanese encephalitis (JE), with an increase in cases seen among adults. However, the reasons for this increase are not clearly understood. This study describes the change in age-specific JE virus (JEV) seroprevalence over time in Korea, with a view to understanding this transition. METHODS: A search of Embase, MEDLINE, PubMed, KoreaMed, Korea Education and Research Information Service, National Library of Korea, and the Seoul National University Medical Library was conducted using the keywords 'Japanese encephalitis' combined with 'Korea', 'seroprevalence', 'seropositivity', 'seroepidemiology', 'serosurvey', 'immunity', and 'antibody'. RESULTS: Eighteen studies published between 1946 and 2012 were retrieved. In 1946, seropositivity was 51% in the 1-10 years age group, 79% in those aged 11-20 years, and 94% in those ≥61 years of age. In the 1970s, seropositivity in children and adolescents was low (10-59%); seropositivity in this group increased to 90-92% in 1984-1985, and increased further to 98% in 2012. Seropositivity among adults aged 41-50 years and 51-60 years in the 2010s ranged between 83.1% and 97.9% and between 77.5% and 98.3%, respectively. CONCLUSIONS: The implementation of the universal JE vaccination programme in the 1980s has increased the seroprevalence of JEV in Korea, especially in children who are targeted for vaccination.
Authors: Nur Suhada Ramli; Norayuni Mohd Ismail; Na'eemah Zaini; Firdaus Hayati; Mohammad Saffree Jeffree; Syed Sharizman Syed Abdul Rahim; Mohd Rohaizat Hassan Journal: Oman Med J Date: 2022-03-22