• Journal of Preventive Medicine and Public Health
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• v.20 no.1 s.21
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• pp.137-146
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• 1987

The following facts have been identified as a result of epidemiological trend and characteristic of Japanese Encephalitis in Korea for the last 20 years. First: The Epidemiological period which was ten-year and three-year in the past has been disappeared following the start of immunization program at 1970. Second: The Incidence rate was much higher in the south and West areas than northeast area of Korea. City and Province with the highest incidence rate was Chungcheong Nam Province and Cholla Buk Province. Third: Regardless of scope of prevalence, the main season that 90 percent of total incidence occurrs in one month from mid-August through mid-September. Fourth: The number of case by age was that 80 percent of total patients is children aged $3{\sim}15$. Recently there is an increase in the number of patients who are elderly people. Fifth: The study on the ecological conditions of mosquito including wintering and effectiveness of immunization for Japanese Encephalitis and duration on antibody should be done. Sixth: There has been no case of Japanese Encephalitis for the last three years since 1984 mainly due to disinfecting to eradicate mosquitos, immunization for vulnerable group of people aged $3{\sim}15$, individual precaution not to be bitten by mosquito, improvement of environment sanitation. While there has been no case of Japanese Encephalitis during last three years, there is possibility that Japanese Encephalitis becomes prevalent again anytime since its virus has been isolated continuously from the natural reservoirs.

• Pediatric Infection and Vaccine
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• v.15 no.2
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• pp.108-114
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• 2008

Japanese encephalitis is the leading cause of viral encephalitis in Asia, where it accounts for up to 50,000 cases. Approximately 20% of affected patients die, and 30-50% of survivors have significant neurological sequelae. Inactivated mouse-brain derived Japanese encephalitis vaccines has been effectively implemented to control the disease effectively in Korea and several other Asian countries. However, the vaccine is expensive and difficult to produce, requires multiple doses, and has been associated with hypersensitivity reactions and rare adverse neurologicale events. The live-attenuated SA14-14-2 vaccine derived from primary hamster kidney (PHK) cells was developed in China and has been used there since 1988. Outside China, it has been licensed and used in Korea and several other Asian countries. This vaccine is effective and inexpensive. However, the lack of precedence for using a PHK cell substrate in a live-attenuated vaccine is a special issue of concern. The WHO working group has recommended additional safety studies in selected high-risk groups, as well as ongoing post-marketing studies to ensure long-term safety. Recently, a new inactivated vaccine and live-attenuated chimeric vaccine have been developed from vero cells. With this background, this article summarized the current status of Japanese encephalitis vaccination worldwide and in Korea.

• The Journal of the Korean Society for Microbiology
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• v.16 no.1
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• pp.83-89
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• 1981

Japanese encephalitis has been prevalent for long time in the Far East and many patients have been reported in both South East and Mid-West Asia recently. Recently, vaccine was used in prevention of this viral disease of man which was derived from formalin inactivated virus inoculated into mouse brain, but live attenuated active vaccine for human is not developed yet. Author inoculated Japanese encephalitis virus into several cell culture strains for development of live attenuated encephalitis virus strain and the results were as follows: 1. Japanese encephalitis virus was inactivated rapidly in cell free medium at $36^{\circ}C$ and totally inactivated by 72 hours. 2. In growth curve of Japanese encephalitis virus in HeLa cell cultures, maximal multiplication of the virus was occured at 4th day and virus multiplication was continued for at least 12 days. 3. After succeeding passage of the virus in HeLa cell cultures and human esophagus epithelial cell cultures, infectivity of virus for mice was disappeared from 2nd passage in HeLa cell cultures and 3rd passage in esophagus epithelial cell cultures. 4. In inoculation to monkey kidney epithelial cells and chick embryo cell cultures, infectivity of the virus for mice was continued after 10th passages.

• Journal of Microbiology and Biotechnology
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• v.32 no.8
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• pp.955-959
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• 2022

Japanese encephalitis (JE) is a vaccine-preventable mosquito-borne disease caused by infection with the Japanese encephalitis virus (JEV). JEV has five genotypes, including genotype V (GV), which is considered ancestral to the other genotypes. The first GV strain, GV Muar, was isolated from a Malayan patient in 1952 and GV did not reappear for 57 years until GV XZ0934 was isolated from a mosquito sample in China. Since 2010, 21 GV strains have been identified in Republic of Korea (ROK). Both GV Muar and GV XZ0934 are more pathogenic than other GI/GIII strains and are serologically distinct. However, because the ROK's GV strains have not been experimentally tested, their characteristics are not known. Characterization of the ROK's isolates is needed to enable development of effective GV strain-based vaccines to protect against GV infections.

• Clinical and Experimental Pediatrics
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• v.65 no.3
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• pp.108-114
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• 2022

The Japanese encephalitis (JE) virus is the leading cause of vaccine-preventable encephalitis in Asia. Since the introduction of a universal JE vaccination program and urbanization of Korea, the incidence of JE has dramatically decreased in Korea. However, recent JE cases have occurred, predominantly among unvaccinated adults and with a shift in age distribution. Here we aimed to review the changes in age-specific JE seroprevalence over time and discuss the implications of JE vaccination programs in Korea. Following the last epidemic in 1982-1983, mandatory vaccination for all children aged 3-15 years was conducted annually until 1994. However, JE has reemerged, predominantly affecting unvaccinated adults aged 40 years or older and demonstrating a shift in age distribution toward older populations. The age-specific seroprevalence of the JE virus in Korea has changed noticeably over time. Seropositivity in children and adolescents increased from 10%-59% in the 1970s to 90%-92% in the 1980s after the implementation of the JE vaccination program and increased further to 98% in 2012. No age-specific difference in the seroprevalence of JE was found, and appropriate levels of immunity to JE were maintained for all age groups. Continuous surveillance of the seroprevalence of JE is essential to establish a proper immunization policy in Korea.

• Annals of Clinical Neurophysiology
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• v.16 no.1
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• pp.35-38
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• 2014

Japanese-B viral encephalitis (JE) usually has a monophasic illness pattern. A 45-year-old woman in an altered mentality had improved over 1 month. About 1 week after the initial improvement, the patient became comatose with aggravated EEG and MRI findings. Assays of cerebrospinal fluid and serum were positive for the IgM antibody to Japanese-B virus. After intravenous immunoglobulin (IVIG) infusion, the patient recovered. We report a patient with JE who showed a biphasic illness pattern and recovered after IVIG therapy.

• Journal of the Korean Society of Radiology
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• v.82 no.2
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• pp.469-474
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• 2021

Japanese encephalitis (JE) is a common infection caused by the Japanese encephalitis virus in Southeast Asia, which is transmitted to humans through Culex mosquitoes. Magnetic resonance imaging (MRI) is used to diagnose JE, which is often characterized by the presence of bilateral symmetric thalamic involvement. Here, we report a rare case of JE characterized by leptomeningeal enhancement without thalamic involvement. This leptomeningeal enhancement disappeared with the treatment; however, new non-specific multifocal and bilateral high signal intensities in the cerebral white matter were found on follow-up MRI.

• Toxicological Research
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• v.13 no.1_2
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• pp.157-160
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• 1997

The primary skin and eye irritancy of the combined vaccine (KGCC-95VI) for the prophylaxis against Japanese encephalitis and Hantaan virus infection recently developed by Korea Green Cross Corporation was investigated. The KGCC-95VI was applied to the back skins of the New Zealand White rabbits. The rabbits were observed for 72 hours and did not exhibit erythema, eschar and edema. The eyes of the rabbits were exposed to the KGCC-95VI. The rabbits were observed for 7 days and did not exhibit any ocular findings on cornea, iris and conjuntivae. The KGCC-95VI is considered not to have the primary skin and eye toxicity in rabbits.

• Korean Journal of Microbiology
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• v.26 no.3
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• pp.149-154
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• 1988

Japanese Encephalitis Virus(JEV) can be detected conveniently by the use of biotinylated cDNA probe. To prepare biotinylated probe aminoallyl dUTP was first synthesized chemically to reverse transcribe the virial RNA. The allylamine-labeled cDNA was then converted to the biotin-cDNA by the reaction with an activated biotin ester, NHS-ACA-biotin. The JEV genomic RNA was hybridized to the biotinylated cDNA probe on nitrocellulose filter and visualized colorimetrically by streptavidin complexes with alkaline phosphatase polymer. Sensitivity of the detection system was determined by estimating the amount of the JEV genomic RNA through comparison with signals generated from the biotinylated and $^{32/P}$ -labeled probes. It was found that the biotin probe was as sensitive as $^{32/P}$ -cDNA probe which can detect 50pgs of the target RNA.

• Investigative Magnetic Resonance Imaging
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• v.20 no.4
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• pp.250-253
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• 2016

Acute Japanese encephalitis (JE) is an endemic viral infectious disease in various parts of Far East and Southeast Asian countries including Korea. Bilateral thalami are the most common involving sites in JE. Other areas including the basal ganglia, substantia nigra, red nucleus, pons, cerebral cortex and cerebellum may be also involved. We report an extremely unusual brain diffusion-weighted MR imaging (DWI) findings in a 53-year-old man with serologically proven JE involving unilateral deep gray matter and temporal lobe, which shows multifocal high signal intensities in left thalamus, left substantia nigra, left caudate nucleus and left medial temporal cortex on T2-weighted image and DWI with iso-intensity on apparent diffusion coefficient (ADC) map.