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Zhang X, Jin N, Tu A, Dong M, Shi T, Ren X, Liu S, Zhao X, Liu J, Wu Z, Li Y, Wu D, Wang H, Wang H, Hu Y, Zhang B, Wang W, Meng L. Adults in Northwest China experienced the largest outbreak of Japanese encephalitis in history 10 years after the Japanese encephalitis vaccine was included in the national immunization program: A retrospective epidemiological study. J Med Virol 2023; 95:e28782. [PMID: 37212323 DOI: 10.1002/jmv.28782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/23/2023] [Accepted: 04/28/2023] [Indexed: 05/23/2023]
Abstract
Mainland China included Japanese encephalitis (JE) vaccine in the national immunization program in 2008 to control the JE epidemic. However, Gansu province in Western China experienced the largest JE outbreak since 1958 in 2018. We conducted a retrospective epidemiological study to explore the causes of this outbreak. We found that adults aged ≥20 years (especially those in rural areas) were the main JE cases in Gansu Province, with a significant increase in the JE incidence in older adults aged ≥60 years in 2017 and 2018. In addition, JE outbreaks in Gansu Province were mainly located in the southeastern region, while the temperature and precipitation in Gansu Province were gradually increasing in recent years, which made the JE epidemic areas in Gansu Province gradually spread to the western of Gansu Province. We also found that adults aged ≥20 years in Gansu Province had lower JE antibody positivity than children and infants, and the antibody positivity rate decreased with age. In the summer of 2017 and 2018, the density of mosquitoes (mainly the Culex tritaeniorhynchus) in Gansu Province was significantly higher than in other years, and the genotype of JEV was mainly Genotype-G1. Therefore, in the future JE control in Gansu Province, we need to strengthen JE vaccination for adults. Moreover, strengthening mosquito surveillance can provide early warning of JE outbreaks and the spread of epidemic areas in Gansu Province. At the same time, strengthening JE antibody surveillance is also necessary for JE control.
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Affiliation(s)
- Xiaoshu Zhang
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Na Jin
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Aixia Tu
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Maoxing Dong
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Tianshan Shi
- Institute of Epidemiology and Health Statistics, School of Public Health, Lanzhou University, Lanzhou, China
| | - Xiaowei Ren
- Institute of Epidemiology and Health Statistics, School of Public Health, Lanzhou University, Lanzhou, China
| | - Shuyu Liu
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Xiaohong Zhao
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Jianfeng Liu
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Zhao Wu
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
| | - Yixing Li
- Department of Immunization Program, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Dan Wu
- Department of Immunization Program, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Huanyu Wang
- Department of Immunization Program, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Haijun Wang
- Department of Immunization Program, Longnan Center for Disease Control and Prevention, Longnan, China
| | - Yukun Hu
- Department of Immunization Program, Pingliang Center for Disease Control and Prevention, Pingliang, China
| | - Bin Zhang
- Department of Immunization Program, Tianshui Center for Disease Control and Prevention, Tianshui, China
| | - Wenjun Wang
- Department of Immunization Program, Qingyang Center for Disease Control and Prevention, Qingyang, China
| | - Lei Meng
- Department of Immunization Program, Gansu Provincial Center for Disease Control and Prevention, Lanzhou, China
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Paulraj PS, Rajamannar V, Renu G, Kumar A. Changing Paradigm in the epidemiology of Japanese encephalitis in India. J Vector Borne Dis 2022; 59:312-319. [PMID: 36751762 DOI: 10.4103/0972-9062.345180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Japanese encephalitis (JE) is a very serious public health problem in India and the conducive environment permit its emergence in non-endemic areas in the country. There are constant changes taking place in the pattern of current agricultural practices and vector breeding habitats which had far-reaching consequences on the epidemiology of JE and the severity of epidemic outbreaks today. Due to the continuous ecological changes taking place, vectors changed in their breeding dynamics, feeding, and resting behavior and started invading previously non-endemic areas. JE has recently spread to new territories due to land-use changes, including forest fragmentation and concentrated livestock production. Changes in the livestock population decreased the cattle pig ratio which enhanced the Japanese encephalitis virus (JEV) infection. This review brings forth the present widespread changes encountered that grossly impact the risk of infection in many places for the emergence of Japanese encephalitis and to address the implications for its control.
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Affiliation(s)
| | | | - Govindarajan Renu
- ICMR-Vector Control Research Centre, Field Station, Madurai, Tamil Nadu, India
| | - Ashwani Kumar
- ICMR Vector Control Research Centre, Puducherry, India
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Aure WE, Sayama Y, Saito-Obata M, Salazar NP, Malbas FF, Galang HO, Imamura T, Zuasula CL, Oshitani H. Japanese encephalitis virus genotype III from mosquitoes in Tarlac, Philippines. IJID REGIONS 2022; 4:59-65. [PMID: 36093364 PMCID: PMC9453045 DOI: 10.1016/j.ijregi.2022.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 05/12/2022] [Accepted: 05/12/2022] [Indexed: 11/27/2022]
Abstract
Japanese encephalitis is endemic in the Philippines. Japanese encephalitis virus genotype III was detected in Culex tritaeniorhynchus. Mosquitoes breed in inundated rice fields close to human habitation. Epidemiological surveillance and immunization of children are identified needs.
Objectives The aim of this study was to investigate the presence of Japanese encephalitis virus (JEV) in a rice-farming community in the Philippines and to determine its implications regarding the epidemiology of viral encephalitides in the Asia-Pacific Region. Methods Mosquitoes were collected monthly from animal-baited traps close to flooded rice fields in two barangays (villages) in the Municipality of San Jose, Tarlac Province in Luzon, from May 2009 to July 2010. Virus was detected by nested reverse transcription PCR. Phylogenetic analysis of the amplified virus envelope gene was done using the maximum-likelihood method. Results A total of 28 700 known vector mosquitoes were collected, namely Culex vishnui, Culex fuscocephala, Culex tritaeniorhynchus, and Culex gelidus. JEV genotype III was detected in C. tritaeniorhynchus, belonging to the same genotype but form a different clade from those reported in the 1980s and in 2020 in this country. Conclusions Japanese encephalitis is associated with rice cultivation and the presence of infected mosquitoes in Tarlac, Philippines. It remains to be seen whether the observed genetic shift of genotype III to genotype I in Asia will in time have an impact on the epidemiology of Japanese encephalitis in the Philippines. For long-term disease control, regular surveillance and Japanese encephalitis immunization in children and travelers in high risk areas are recommended.
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Lee AR, Song JM, Seo SU. Emerging Japanese Encephalitis Virus Genotype V in Republic of Korea. J Microbiol Biotechnol 2022; 32:955-959. [PMID: 35879275 PMCID: PMC9628952 DOI: 10.4014/jmb.2207.07002] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/20/2022] [Accepted: 07/21/2022] [Indexed: 12/15/2022]
Abstract
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.
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Affiliation(s)
- Ah-Ra Lee
- Department of Biomedicine and Health Sciences, Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea
| | - Jae Min Song
- School of Biopharmaceutical and Medical Sciences, Sungshin Women’s University, Seoul 01133, Republic of Korea
| | - Sang-Uk Seo
- Department of Biomedicine and Health Sciences, Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea,Corresponding author Phone: +82-2-2258-7355 Fax: +82-2-2258-8969 E-mail:
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Abstract
PURPOSE OF REVIEW To discuss the neurological complications of dengue virus (DENV) infection and their pathogenesis. RECENT FINDINGS Include recognition of the four different serotypes of DENV and their epidemiology as well as recognition of the expanded dengue syndrome encompassing multisystem involvement in the severe form of the disease including involvement of the central nervous system (CNS). DENV is a neurotropic virus with the ability to infect the supporting cells of the CNS. Neural injury during the acute stage of the infection results from direct neuro-invasion and/or the phenomenon of antibody-dependent enhancement, resulting in plasma leakage and coagulopathy. Immune mechanisms have been implicated in the development of the delayed neurological sequelae through molecular mimicry. A myriad of neurological syndromes has been described as a result of the involvement of the CNS, the peripheral nervous system (PNS), or both. Neurological manifestations in DENV infection are increasingly being recognized, some of which are potentially fatal if not treated promptly. DENV encephalopathy and encephalitis should be considered in the differential diagnosis of other acute febrile encephalopathies, autoimmune encephalitides, and in cases of encephalopathy/encephalitis related to SARS-CoV2 infection, especially in dengue-endemic areas. Acute disseminated encephalomyelitis (ADEM) may be occasionally encountered. Clinicians should be knowledgeable of the expanded dengue syndrome characterized by the concurrent compromise of cardiac, neurological, gastrointestinal, renal, and hematopopoietic systems. Isolated cranial nerve palsies occur rather uncommonly and are often steroid responsive. These neuropathies may result from the direct involvement of cranial nerve nuclei or nerve involvement or may be immune-mediated. Even if the diagnosis of dengue is confirmed, it is absolutely imperative to exclude other well-known causes of isolated cranial nerve palsies. Ischemic and hemorrhagic strokes may occur following dengue fever. The pathogenesis may be beyond the commonly observed thrombocytopenia and include cerebral vasculitis. Involvement of ocular blood vessels may cause maculopathy or retinal hemorrhages. Posterior reversible encephalopathy syndrome (PRES) is uncommon and possibly related to dysregulated cytokine release phenomena. Lastly, any patient developing acute neuromuscular weakness during the course or within a fortnight of remission from dengue fever must be screened for acute inflammatory demyelinating polyneuropathy (AIDP), hypokalemic paralysis, or acute myositis. Rarely, a Miller-Fisher-like syndrome with negative anti-GQ1b antibody may develop.
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Affiliation(s)
- Sweety Trivedi
- Department of Neurology, Sanjay Gandhi Postgraduate Institute of Medical Science, Lucknow, India
| | - Ambar Chakravarty
- Department of Neurology, Vivekananda Institute of Medical Science, Kolkata, India.
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Kwak BO, Hong YJ, Kim DH. Changes in age-specific seroprevalence of Japanese encephalitis virus and impact of Japanese encephalitis vaccine in Korea. Clin Exp Pediatr 2022; 65:108-114. [PMID: 34592804 PMCID: PMC8898622 DOI: 10.3345/cep.2020.01984] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 09/11/2021] [Indexed: 11/27/2022] Open
Abstract
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.
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Affiliation(s)
- Byung Ok Kwak
- Department of Pediatrics, Hallym University Kangnam Sacred Heart Hospital, Seoul, Korea
| | - Young Jin Hong
- Department of Pediatrics, Inha University School of Medicine, Incheon, Korea
| | - Dong Hyun Kim
- Department of Pediatrics, Inha University School of Medicine, Incheon, Korea
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Abstract
Japanese encephalitis (JE) is an endemic disease dominantly in the Asia-Pacific region with mortality rate varying between 3% and 30%. Long-term neuropsychiatric sequelae developed in 30–50% of the survivors. There is no available antiviral therapy for JE. JE vaccines play a major role in preventing this devastating disease. The incidence of JE declined over years and the age distribution shifted toward adults in countries where JE immunization program exists. Mouse brain–JE vaccine is currently replaced by inactivated Vero cell-derived vaccine and live-attenuated vaccine using SA14-14-2 strain, and live chimeric JE vaccines. These three types of JE vaccines are associated with favorable efficacy and safety profiles. Common adverse reactions include injection site reactions and fever, and severe adverse reactions are rare.
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Affiliation(s)
- Ya-Li Hu
- Department of Pediatrics, Cathay General Hospital, Taipei, Taiwan
| | - Ping-Ing Lee
- Department of Pediatrics, National Taiwan University Hospital, and National Taiwan University College of Medicine, Taipei, Taiwan
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Fang Y, Li XS, Zhang W, Xue JB, Wang JZ, Yin SQ, Li SG, Li XH, Zhang Y. Molecular epidemiology of mosquito-borne viruses at the China-Myanmar border: discovery of a potential epidemic focus of Japanese encephalitis. Infect Dis Poverty 2021; 10:57. [PMID: 33902684 PMCID: PMC8073957 DOI: 10.1186/s40249-021-00838-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 04/08/2021] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Mosquito-based arbovirus surveillance can serve as an early warning in evaluating the status of mosquito-borne virus prevalence and thus prevent local outbreaks. Although Tengchong County in Yunnan Province-which borders Myanmar-is abundant and diverse in mosquitoes, very few mosquito-based arbovirus investigations have been conducted in the recent decade. Herein, this study aims to evaluate the presence and the diffusion of mosquito-borne pathogens, currently prevalent in this region. METHODS We collected 9486 mosquitoes, representing eight species, with Culex tritaeniorhynchus and Anopheles sinensis as the dominant species, during high mosquito activity seasons (July-October) in Tengchong, in 2018. Samples collected from 342 pools were tested using reverse-transcription PCR to determine the species, distribution, and infection rates of virus and parasite, and further analyze their genotypes, phylogenetic relationships, infection rate, and potential pathogenicity. RESULTS Fifteen Japanese encephalitis virus (JEV) strains from Cx. tritaeniorhynchus pools were detected. Seven strains of insect-specific flaviviruses (ISFVs), including two Aedes flavivirus (AeFV) and Yunnan Culex flavivirus strains each, one Culex theileri flavivirus, Yamadai flavivirus (YDFV) and Anopheles-associated flavivirus (AAFV) strains each were detected in Aedes albopictus, Cx. tritaeniorhynchus, Cx. vagans, Cx. pseudovihnui, and An. sinensis pools, respectively. The whole-genome was successfully amplified in one strain of JEV and AeFV each. Phylogenetic analysis using the E gene placed all the newly detected JEV strains into the GI-b genotype. They showed highly nucleotide identities, and were most closely related to the strain detected in Tengchong in 2010. The comparison of the E protein of JEV strains and vaccine-derived strain, showed six amino residue differences. The bias-corrected maximum likelihood estimation values (and 95% confidence interval) for JEV in Cx. tritaeniorhynchus collected in Tengchong in 2018 were 2.4 (1.4-3.9). CONCLUSIONS A potential Japanese encephalitis epidemic focus with the abundance of host mosquitoes and high JEV infection rate was observed in Tengchong. In addition, at least five species of ISFVs co-circulate in this area. This study highlights the importance of widespread and sustained mosquito-based arbovirus surveillance in local areas to prevent the transmission of JEV, and other emerging/re-emerging mosquito-borne pathogens.
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Affiliation(s)
- Yuan Fang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research); NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Shanghai, China
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xi-Shang Li
- Tengchong County Center for Disease Control and Prevention, Tengchong, Yunnan, China
| | - Wei Zhang
- Zichuan District Center for Disease Control and Prevention, Shandong, Zibo, China
| | - Jing-Bo Xue
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research); NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Shanghai, China
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jia-Zhi Wang
- Tengchong County Center for Disease Control and Prevention, Tengchong, Yunnan, China
| | - Shou-Qin Yin
- Zichuan District Center for Disease Control and Prevention, Shandong, Zibo, China
| | - Sheng-Guo Li
- Tengchong County Center for Disease Control and Prevention, Tengchong, Yunnan, China
| | - Xin-He Li
- Tengchong County Center for Disease Control and Prevention, Tengchong, Yunnan, China
| | - Yi Zhang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research); NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Shanghai, China.
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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Faizah AN, Kobayashi D, Amoa-Bosompem M, Higa Y, Tsuda Y, Itokawa K, Miura K, Hirayama K, Sawabe K, Isawa H. Evaluating the competence of the primary vector, Culex tritaeniorhynchus, and the invasive mosquito species, Aedes japonicus japonicus, in transmitting three Japanese encephalitis virus genotypes. PLoS Negl Trop Dis 2020; 14:e0008986. [PMID: 33370301 PMCID: PMC7793266 DOI: 10.1371/journal.pntd.0008986] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 01/08/2021] [Accepted: 11/12/2020] [Indexed: 01/13/2023] Open
Abstract
Japanese encephalitis virus (JEV) is maintained in an enzootic cycle between swine, water birds, and mosquitoes. JEV has circulated indigenously in Asia, with Culex tritaeniorhynchus as the primary vector. In some areas where the primary vector is scarce or absent, sporadic cases of Japanese encephalitis have been reported, with Aedes japonicus japonicus presumed to have the potential as a secondary vector. As one of the world's most invasive culicid species, Ae. j. japonicus carries a considerable health risk for spreading diseases to wider areas, including Europe and North America. Thus, evaluation of its competency as a JEV vector, particularly in a native population, will be essential in preventing potential disease spread. In this study, the two mosquito species' vector competence in transmitting three JEV genotypes (I, III, and V) was assessed, with Cx. tritaeniorhynchus serving as a point of reference. The mosquitoes were virus-fed and the infection rate (IR), dissemination rate (DR), and transmission rate (TR) evaluated individually by either RT-qPCR or focus forming assay. Results showed striking differences between the two species, with IR of 95% (261/274) and 9% (16/177) in Cx. tritaeniorhynchus and Ae. j. japonicus, respectively. Both mosquitoes were susceptible to all three JEV genotypes with significant differences in IR and mean viral titer. Results confirm the primary vector's competence, but the fact that JEV was able to establish in Ae. j. japonicus is of public health significance, and with 2%-16% transmission rate it has the potential to successfully transmit JEV to the next host. This may explain the human cases and infrequent detection in primary vector-free areas. Importantly, Ae. j. japonicus could be a relevant vector spreading the disease into new areas, indicating the need for security measures in areas where the mosquito is distributed or where it may be introduced.
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Affiliation(s)
- Astri Nur Faizah
- Laboratory of Veterinary Public Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, Japan
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
| | - Daisuke Kobayashi
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
| | - Michael Amoa-Bosompem
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
- Department of Environmental Parasitology, Tokyo Medical and Dental University, Bunkyo, Tokyo, Japan
| | - Yukiko Higa
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
| | - Yoshio Tsuda
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
| | - Kentaro Itokawa
- Pathogen Genomics Center, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
| | - Kozue Miura
- Laboratory of Veterinary Public Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Kazuhiro Hirayama
- Laboratory of Veterinary Public Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Kyoko Sawabe
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
| | - Haruhiko Isawa
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
- * E-mail:
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Lee HJ, Choi H, Park KH, Jang Y, Hong YJ, Kim YB. Retention of neutralizing antibodies to Japanese encephalitis vaccine in age groups above fifteen years in Korea. Int J Infect Dis 2020; 100:53-58. [DOI: 10.1016/j.ijid.2020.08.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 08/13/2020] [Accepted: 08/16/2020] [Indexed: 10/23/2022] Open
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Kim HS, Oh Y, Korejwo J, Castells VB, Yang K. Post-Marketing Surveillance of Adverse Events Following Vaccination with the Live-Attenuated Japanese Encephalitis Chimeric Virus Vaccine (Imojev ®) in South Korea, 2015-2019. Infect Dis Ther 2020; 9:589-598. [PMID: 32474892 PMCID: PMC7452989 DOI: 10.1007/s40121-020-00305-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Indexed: 11/24/2022] Open
Abstract
INTRODUCTION The live attenuated Japanese encephalitis chimeric virus vaccine (JE-CV; Imojev®) has been approved in South Korea for use in subjects aged ≥ 12 months since 2015. As part of the license agreement, a post-marketing surveillance study was undertaken to actively monitor the safety profile of JE-CV in the Korean population. METHODS An observational, active safety surveillance study was conducted from 3 April 2015 through to 2 April 2019 at 12 centers in South Korea. Subjects aged ≥ 12 months who received a single dose of JE-CV (primary or booster) during a routine healthcare visit were recruited and followed up for solicited reactions (7 and 14 days for injection site and systemic reactions, respectively), non-serious unsolicited adverse events and serious adverse events within 42 days after vaccination. RESULTS Overall, 810 subjects who received JE-CV were included in our analysis, the majority received the vaccine as a primary vaccination (94.9%; 769/810). There were 179 solicited reactions reported by 111 subjects; the majority of solicited reactions occurred within 0-3 days (80.4%; 144/179), were of 1-3 days' duration (79.3%; 142/179) and of grade 1 intensity (70.9%; 127/179). There were three grade 3 adverse reactions (irritability, pyrexia and malaise); all resolved within a few days. The incidence of solicited reactions were highest in those aged 12 to < 24 months (34.7% [52/150] subjects; 107 events) and 2 to < 10 years (17.8% [8/45] subjects; 14 events). All unsolicited adverse events (serious and non-serious) were unrelated to vaccination. There were no discontinuations due to adverse reactions/events. CONCLUSION JE-CV has a good safety profile under practice conditions in South Korea. No new safety issues were identified. TRIAL REGISTRATION ClinicalTrials.gov identifier, NCT02933710.
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Affiliation(s)
| | - Yongho Oh
- Sanofi Singapore, South Beach Tower, Singapore, Singapore
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Deng X, Yan JY, He HQ, Yan R, Sun Y, Tang XW, Zhou Y, Pan JH, Mao HY, Zhang YJ, Lv HK. Serological and molecular epidemiology of Japanese Encephalitis in Zhejiang, China, 2015-2018. PLoS Negl Trop Dis 2020; 14:e0008574. [PMID: 32853274 PMCID: PMC7491720 DOI: 10.1371/journal.pntd.0008574] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 09/15/2020] [Accepted: 07/07/2020] [Indexed: 01/01/2023] Open
Abstract
Background Shifts have occurred in the epidemiological characteristics of Japanese encephalitis (JE), extending from the molecular level to the population level. The aim of this study was to investigate the seroprevalence of JE neutralizing antibodies in healthy populations from different age groups in Zhejiang Province, and to conduct mosquito monitoring to evaluate the infection rate of Japanese encephalitis virus (JEV) among vectors, as well as the molecular characteristics of the E gene of isolated JEV strains. Methodology/Principal findings A total of 1190 sera samples were screened by a microseroneutralization test, including 429 infants (28d-11m) and 761 participants (2y-82y). For those under 1 year old, the geometric mean titers (GMTs) of the JE neutralizing antibody was 9.49 at birth and significantly declined as the age of month increased (r = -0.225, P<0.001). For those above 1-year old, seropositive proportions were higher in subjects aged 1–3 years old as well as ≥25 years old (65%-75%), and relatively lower in subjects aged between 4–25 years old (22%-55%). Four or more years after the 2nd dose of JEV-L (first dose administered at 8 months and the second at 2 years of age), the seropositive proportion decreased to 32.5%, and GMTs decreased to 8.08. A total of 87,201 mosquitoes were collected from livestock sheds in 6 surveillance sites during 2015–2018, from which 139 E gene sequences were successfully amplified. The annual infection rate according to bias-corrected maximum likelihood estimation of JEV in Culex tritaeniorhynchus was 1.56, 2.36, 5.65 and 1.77 per 1000, respectively. JEV strains isolated during 2015–2018 all belonged to Genotype I. The E gene of amplified 139 samples differed from the JEV-L vaccine strain at fourteen amino acid residues, including the eight key residues related to virulence and virus attenuation. No divergence was observed at the sites related to antigenicity. Conclusions/Significance Zhejiang Province was at a high risk of JE exposure due to relatively lower neutralizing antibody levels among the younger-aged population and higher infection rates of JEV in mosquitoes. Continuous, timely and full coverage of JE vaccination are essential, as well as the separation of human living areas and livestock shed areas. In addition, annual mosquito surveillance and periodic antibody level monitoring are important for providing evidence for improvement in JE vaccines and immunization schedules. Although Japanese encephalitis (JE) has been well-controlled in Zhejiang Province, it remains a hot public health issue due to heavy disease burden. The epidemiological characteristics of JE have changed recently in Zhejiang Province. Increasing proportion of adult cases (>40 years old) have been reported. Genotype I (GI) of JEV has displaced genotype III (GIII) as the dominant genotype. The population immunity against JE was notably low among participants aged 4–25 years old, with the lowest GMT being in the 7-14-year-old group. Two doses of JEV-L did not provide effective protection after 4 or more years past the 2nd dose. Therefore, issues about duration of protection and necessity of a booster dose at 6 years of age need further research. JEV strains isolated from mosquitoes during 2015–2018 in Zhejiang Province all belonged to GI. Compared with the JE vaccine strain, mutations at the eight amino acid residues on E gene related to virulence in Zhejiang strains were detected, while the antigenic sites remained the same. JE serological survey in healthy populations with different sequential immunization schedule should be conducted to provide evidence for reformation on JE immunization strategy, including type, dose and interval.
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MESH Headings
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Animals
- Antibodies, Neutralizing
- Child
- Child, Preschool
- China/epidemiology
- Cross-Sectional Studies
- Culex/virology
- Culicidae/virology
- Encephalitis Virus, Japanese/classification
- Encephalitis Virus, Japanese/genetics
- Encephalitis Virus, Japanese/immunology
- Encephalitis Virus, Japanese/isolation & purification
- Encephalitis, Japanese/epidemiology
- Encephalitis, Japanese/virology
- Genes, Viral/genetics
- Humans
- Infant
- Infant, Newborn
- Middle Aged
- Molecular Epidemiology
- Mosquito Vectors/virology
- Seroepidemiologic Studies
- Young Adult
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Affiliation(s)
- Xuan Deng
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, People’s Republic of China
| | - Ju-ying Yan
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, People’s Republic of China
- * E-mail:
| | - Han-qing He
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, People’s Republic of China
| | - Rui Yan
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, People’s Republic of China
| | - Yi Sun
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, People’s Republic of China
| | - Xue-wen Tang
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, People’s Republic of China
| | - Yang Zhou
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, People’s Republic of China
| | - Jun-hang Pan
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, People’s Republic of China
| | - Hai-yan Mao
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, People’s Republic of China
| | - Yan-jun Zhang
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, People’s Republic of China
| | - Hua-kun Lv
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, People’s Republic of China
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13
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A need to raise the bar - A systematic review of temporal trends in diagnostics for Japanese encephalitis virus infection, and perspectives for future research. Int J Infect Dis 2020; 95:444-456. [PMID: 32205287 PMCID: PMC7294235 DOI: 10.1016/j.ijid.2020.03.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/09/2020] [Accepted: 03/15/2020] [Indexed: 12/14/2022] Open
Abstract
Japanese encephalitis virus (JEV) remains a leading cause of neurological infection in Asia. A systematic review identified 20,212 published human cases of laboratory-confirmed JEV infections from 205 studies. 15,167 (75%) of cases were confirmed with the lowest confidence diagnostic test, i.e., level 3 or 4, or level 4. Only 109 (53%) of the studies reported contemporaneous testing for dengue-specific antibodies. A fundamental pre-requisite for the control of JE is lacking — that of a simple and specific diagnostic procedure that can be adapted for point-of-care tests and readily used throughout JE endemic regions of the world.
Objective Japanese encephalitis virus infection (JE) remains a leading cause of neurological disease in Asia, mainly involving individuals living in remote areas with limited access to treatment centers and diagnostic facilities. Laboratory confirmation is fundamental for the justification and implementation of vaccination programs. We reviewed the literature on historical developments and current diagnostic capability worldwide, to identify knowledge gaps and instill urgency to address them. Methods Searches were performed in Web of Science and PubMed using the term 'Japanese encephalitis' up to 13th October 2019. Studies reporting laboratory-confirmed symptomatic JE cases in humans were included, and data on details of diagnostic tests were extracted. A JE case was classified according to confirmatory levels (Fischer et al., 2008; Campbell et al., 2011; Pearce et al., 2018; Heffelfinger et al., 2017), where level 1 represented the highest level of confidence. Findings 20,212 published JE cases were identified from 205 studies. 15,167 (75%) of these positive cases were confirmed with the lowest-confidence diagnostic tests (level 3 or 4, or level 4). Only 109 (53%) of the studies reported contemporaneous testing for dengue-specific antibodies. Conclusion A fundamental pre-requisite for the control of JEV is lacking — that of a simple and specific diagnostic procedure that can be adapted for point-of-care tests and readily used throughout JE-endemic regions of the world.
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Win AYN, Wai KT, Harries AD, Kyaw NTT, Oo T, Than WP, Lin HH, Lin Z. The burden of Japanese encephalitis, the catch-up vaccination campaign, and health service providers' perceptions in Myanmar: 2012-2017. Trop Med Health 2020; 48:13. [PMID: 32161512 PMCID: PMC7059723 DOI: 10.1186/s41182-020-00200-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 02/27/2020] [Indexed: 01/28/2023] Open
Abstract
Background Myanmar is endemic for Japanese encephalitis (JE) and has experienced several outbreaks in recent years. The vector-borne disease control (VBDC) program has collected hospital-based surveillance data since 1974. There is an urgent need to collate, analyze, and interpret the most recent information. The study aimed to describe (i) hospital-based JE cases and deaths between 2012 and 2017, (ii) a catch-up vaccination campaign in children in 2017, and (iii) health service provider perceptions about JE in one township in 2018. Methods This was a cross-sectional study of cases, deaths, and catch-up childhood vaccinations using secondary data from program records and a survey database of health service provider perceptions. Results Between 2012 and 2017, there were 872 JE cases and 79 deaths with a case fatality rate of 91 per 1000; 2016 was the year with most cases and deaths. Most cases (n = 324) and deaths (n = 37) occurred in children aged 5–9 years. Large case numbers were reported in delta and lowland regions (n = 550) and during the wet season (n = 580). The highest case fatality rates were observed in the hills and coastal regions (120 and 112 per 1000, respectively). Nationwide coverage of the catch-up JE vaccination campaign among 13.7 million eligible children was 92%, with coverage lower in the hills and coastal regions (84%) compared with delta and lowland regions and plains (94%). More vaccinations (65%) occurred through school-based campaigns with the remainder (35%) vaccinated through community-based campaigns. Structured interviews in one township showed that service providers (n = 47) had good perceptions about various aspects of JE, although perceived benefits of specific vector control measures were poor: spraying/fumigation (38%), garbage removal (36%), larvicide use (36%), and drainage of standing/stagnant water (32%). Conclusion The catch-up vaccination campaign was a successful response to high JE case numbers and deaths in children. However, ongoing surveillance for JE needs to continue and be strengthened to ensure comprehensive reporting of all cases, more knowledge is needed on disability in JE survivors, and all attempts must be made to ensure high percentage coverage of vaccination through routine and catch-up campaigns.
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Affiliation(s)
- Aung Ye Naung Win
- 1Epidemiology Research Division, Department of Medical Research, Ministry of Health and Sports, No. 5, Ziwaka Road, Dagon Township, Yangon, 11191 Myanmar
| | - Khin Thet Wai
- 1Epidemiology Research Division, Department of Medical Research, Ministry of Health and Sports, No. 5, Ziwaka Road, Dagon Township, Yangon, 11191 Myanmar
| | - Anthony D Harries
- 2International Union against Tuberculosis and Lung Disease, Paris, France.,3London School of Hygiene and Tropical Medicine, London, UK
| | - Nang Thu Thu Kyaw
- 2International Union against Tuberculosis and Lung Disease, Paris, France
| | - Tin Oo
- 1Epidemiology Research Division, Department of Medical Research, Ministry of Health and Sports, No. 5, Ziwaka Road, Dagon Township, Yangon, 11191 Myanmar
| | - Wint Phyo Than
- 4Vector Borne Disease Control Program, Ministry of Health and Sports, Naypyitaw, Myanmar
| | - Htar Htar Lin
- 5Expanded Program on Immunization, Ministry of Health and Sports, Naypyitaw, Myanmar
| | - Zaw Lin
- 6WHO South East Asia Regional Office, New Delhi, India
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15
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Lee PI, Huang YC, Hwang KP, Liu CC, Chiu CH, Chen PY, Lu CY, Chen CJ, Chang LY, Chiu NC, Chi H, Lin HC, Wu KG, Ho YH, Sun W, Lin TY. Recommendations for the use of Japanese encephalitis vaccines. Pediatr Neonatol 2020; 61:3-8. [PMID: 31870559 DOI: 10.1016/j.pedneo.2019.11.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 06/03/2019] [Accepted: 11/21/2019] [Indexed: 12/28/2022] Open
Abstract
Japanese encephalitis (JE) is a mosquito-borne viral infection which is prevalent in Taiwan. The virus circulates in an enzootic cycle in pigs which serve as amplifying hosts. Outbreaks typically occur during summer. A universal vaccination program using 4-shot mouse brain-derived inactivated vaccine has successfully controlled JE epidemics in Taiwan since 1968. More than 90% of JE cases in recent years were older than 20 years in Taiwan. Because of several drawbacks, mouse brain-derived vaccine has been replaced by newer generation JE vaccines, including inactivated Vero cell-derived vaccine and live chimeric vaccine. The present article describes the recommendations in Taiwan for the use of new JE vaccines and the schedules for shifting between different JE vaccines.
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Affiliation(s)
- Ping-Ing Lee
- Department of Pediatrics, National Taiwan University Children's Hospital, National Taiwan University Hospital and National Taiwan University College of Medicine, National Taiwan University, Taiwan.
| | - Yhu-Chering Huang
- Division of Infectious Diseases, Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taiwan
| | - Kao-Pin Hwang
- School of Medicine, China Medical University; Division of Pediatric Infectious Diseases, China Medical University Children's Hospital, Taiwan
| | - Ching-Chuan Liu
- Department of Pediatrics, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Taiwan
| | - Cheng-Hsun Chiu
- Division of Infectious Diseases, Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taiwan
| | - Po-Yen Chen
- Section of Pediatric Infectious Diseases, Department of Pediatrics, Taichung Veterans General Hospital, Taiwan
| | - Chun-Yi Lu
- Department of Pediatrics, National Taiwan University Children's Hospital, National Taiwan University Hospital and National Taiwan University College of Medicine, National Taiwan University, Taiwan
| | - Chih-Jung Chen
- Division of Infectious Diseases, Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taiwan
| | - Luan-Yin Chang
- Department of Pediatrics, National Taiwan University Children's Hospital, National Taiwan University Hospital and National Taiwan University College of Medicine, National Taiwan University, Taiwan
| | - Nan-Chang Chiu
- Department of Pediatrics, MacKay Children's Hospital, Taiwan
| | - Hsin Chi
- Department of Pediatrics, MacKay Children's Hospital, Taiwan
| | - Hsiao-Chuan Lin
- School of Medicine, China Medical University; Division of Pediatric Infectious Diseases, China Medical University Children's Hospital, Taiwan
| | - Keh-Gong Wu
- Department of Pediatrics, Taipei Veterans General Hospital and National Yang-Ming University, Taiwan
| | - Yu-Huai Ho
- Division of Infection Diseases, Department of Internal Medicine, Buddhist Tzu Chi General Hospital and Tzu Chi University, Taiwan
| | - Wu Sun
- Pao-Chien Hospital, Taiwan
| | - Tzou-Yien Lin
- Division of Infectious Diseases, Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taiwan
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16
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Hills SL, Walter EB, Atmar RL, Fischer M. Japanese Encephalitis Vaccine: Recommendations of the Advisory Committee on Immunization Practices. MMWR Recomm Rep 2019; 68:1-33. [PMID: 31518342 PMCID: PMC6659993 DOI: 10.15585/mmwr.rr6802a1] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
This report updates the 2010 recommendations from the CDC Advisory Committee on Immunization Practices (ACIP) regarding prevention of Japanese encephalitis (JE) among U.S. travelers and laboratory workers (Fischer M, Lindsey N, Staples JE, Hills S. Japanese encephalitis vaccines: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 2010;59[No. RR-1]). The report summarizes the epidemiology of JE, describes the JE vaccine that is licensed and available in the United States, and provides recommendations for its use among travelers and laboratory workers.JE virus, a mosquitoborne flavivirus, is the most common vaccine-preventable cause of encephalitis in Asia. JE occurs throughout most of Asia and parts of the western Pacific. Approximately 20%-30% of patients die, and 30%-50% of survivors have neurologic, cognitive, or behavioral sequelae. No antiviral treatment is available.Inactivated Vero cell culture-derived JE vaccine (Ixiaro [JE-VC]) is the only JE vaccine that is licensed and available in the United States. In 2009, the U.S. Food and Drug Administration (FDA) licensed JE-VC for use in persons aged ≥17 years; in 2013, licensure was extended to include children aged ≥2 months.Most travelers to countries where the disease is endemic are at very low risk for JE. However, some travelers are at increased risk for infection on the basis of their travel plans. Factors that increase the risk for JE virus exposure include 1) traveling for a longer period; 2) travel during the JE virus transmission season; 3) spending time in rural areas; 4) participating in extensive outdoor activities; and 5) staying in accommodations without air conditioning, screens, or bed nets. All travelers to countries where JE is endemic should be advised to take precautions to avoid mosquito bites to reduce the risk for JE and other vectorborne diseases. For some persons who might be at increased risk for JE, the vaccine can further reduce the risk for infection. The decision about whether to vaccinate should be individualized and consider the 1) risks related to the specific travel itinerary, 2) likelihood of future travel to countries where JE is endemic, 3) high morbidity and mortality of JE, 4) availability of an effective vaccine, 5) possibility (but low probability) of serious adverse events after vaccination, and 6) the traveler's personal perception and tolerance of risk.JE vaccine is recommended for persons moving to a JE-endemic country to take up residence, longer-term (e.g., ≥1 month) travelers to JE-endemic areas, and frequent travelers to JE-endemic areas. JE vaccine also should be considered for shorter-term (e.g., <1 month) travelers with an increased risk for JE on the basis of planned travel duration, season, location, activities, and accommodations and for travelers to JE-endemic areas who are uncertain about their specific travel duration, destinations, or activities. JE vaccine is not recommended for travelers with very low-risk itineraries, such as shorter-term travel limited to urban areas or outside of a well-defined JE virus transmission season.
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17
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Wang R, Xie L, Gao N, Fan D, Chen H, Wang P, Zhou H, An J. Decreases in Both the Seroprevalence of Serum Antibodies and Seroprotection against Japanese Encephalitis Virus among Vaccinated Children. Virol Sin 2019; 34:243-252. [PMID: 30911897 DOI: 10.1007/s12250-019-00099-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 02/01/2019] [Indexed: 02/02/2023] Open
Abstract
The incidence of Japanese encephalitis (JE) has significantly decreased in China due to JE vaccines. In this study, we investigated the post-JE vaccination seroprevalence and protection provided by vaccinated sera against Japanese encephalitis virus (JEV) to elucidate the persistence and waning of antibodies to JEV among JE-SA14-14-2-vaccinated children. A total of 300 serum samples were collected from vaccinated children aged 3-10 years in Zhaotong, Yunnan, China. The seroprevalence of anti-JEV antibodies was determined by enzyme-linked immune sorbent assay and plaque reduction neutralization test. The highest seropositivity of 82% was observed in vaccinated children during the first 0.5-1.5 years after booster vaccination. Then, the seropositivity began to decline and remained lower than the original level observed in the 0.5-1.5-year group. An association was found between the waning of seroprevalence and elapsed time of the post-booster vaccination. Similarly, the neutralizing antibody (nAb) titres gradually decreased over time, and the levels showed a positive correlation with the protective efficacy in mice. This finding suggests that nAbs play an important role in the antiviral process and that the nAb titre is an adequately credible parameter for evaluating the protective efficacy induced by the JE vaccine. Our results provide data that clarify the persistence and waning of antibodies to JEV, which may help elucidate the pathogenesis of JE.
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Affiliation(s)
- Ran Wang
- Department of Microbiology, School of Basic Medical Sciences, Chinese Capital Medical University, Beijing, 100069, China
| | - Lyu Xie
- Yunnan Provincial Key Laboratory of Vector-borne Disease Control and Research, Yunnan Institute of Parasitic Diseases, Pu'er, 665000, China
| | - Na Gao
- Department of Microbiology, School of Basic Medical Sciences, Chinese Capital Medical University, Beijing, 100069, China
| | - Dongying Fan
- Department of Microbiology, School of Basic Medical Sciences, Chinese Capital Medical University, Beijing, 100069, China
| | - Hui Chen
- Department of Microbiology, School of Basic Medical Sciences, Chinese Capital Medical University, Beijing, 100069, China
| | - Peigang Wang
- Department of Microbiology, School of Basic Medical Sciences, Chinese Capital Medical University, Beijing, 100069, China
| | - Hongning Zhou
- Yunnan Provincial Key Laboratory of Vector-borne Disease Control and Research, Yunnan Institute of Parasitic Diseases, Pu'er, 665000, China.
| | - Jing An
- Department of Microbiology, School of Basic Medical Sciences, Chinese Capital Medical University, Beijing, 100069, China. .,Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing, 100069, China.
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Fang Y, Zhang Y, Zhou ZB, Xia S, Shi WQ, Xue JB, Li YY, Wu JT. New strains of Japanese encephalitis virus circulating in Shanghai, China after a ten-year hiatus in local mosquito surveillance. Parasit Vectors 2019; 12:22. [PMID: 30626442 PMCID: PMC6327439 DOI: 10.1186/s13071-018-3267-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 12/12/2018] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Continuous vector pathogen surveillance is essential for preventing outbreaks of mosquito-borne diseases. Several mosquito species acting as vectors of Japanese encephalitis virus (JEV), dengue virus, Zika virus, malaria parasites and other pathogens are primary mosquito species in Shanghai, China. However, few surveys of human pathogenic arboviruses in mosquitoes in Shanghai have been reported in the last ten years. Therefore, in this study, we evaluated mosquito activity in Shanghai, China during 2016 and tested for the presence of alphaviruses, flaviviruses, orthobunyaviruses and several parasitic pathogens. RESULTS Five pooled samples were JEV-positive [4/255 pools of Culex tritaeniorhynchus and 1/256 pools of Cx. pipiens (s.l.)] based on analysis of the NS5 gene. Alphaviruses, orthobunyaviruses, Plasmodium and filariasis were not found in this study. Phylogenetic and molecular analyses revealed that the JEV strains belonged to genotype I. Moreover, newly detected Shanghai JEV strains were genetically close to previously isolated Shandong strains responsible for transmission during the 2013 Japanese encephalitis (JE) outbreak in Shandong Province, China but were more distantly related to other Shanghai strains detected in the early 2000s. The E proteins of the newly detected Shanghai JEV strains differed from that in the live attenuated vaccine SA14-14-2-derived strain at six amino residues: E130 (Ile→Val), E222 (Ala→Ser), E327 (Ser→Thr), E366 (Arg→Ser/Pro), E393 (Asn→Ser) and E433 (Val→Ile). However, no differences were observed in key amino acid sites related to antigenicity. Minimum JEV infection rates were 1.01 and 0.65 per 1000 Cx. tritaeniorhynchus and Cx. pipiens (s.l.), respectively. CONCLUSIONS Five new Shanghai JEV genotype I strains, detected after a ten-year hiatus in local mosquito surveillance, were genetically close to strains involved in the 2013 Shandong JE outbreak. Because JEV is still circulating, vaccination in children should be extensively and continuously promoted. Moreover, JEV mosquito surveillance programmes should document the genotype variation, intensity and distribution of circulating viruses for use in the development and implementation of disease prevention and control strategies.
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Affiliation(s)
- Yuan Fang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
| | - Yi Zhang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
| | - Zheng-Bin Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
| | - Shang Xia
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
| | - Wen-Qi Shi
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
| | - Jing-Bo Xue
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
| | - Yuan-Yuan Li
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
| | - Jia-Tong Wu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
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Shin ES, Park O, Kong IS. Review of the Incidence of Japanese Encephalitis in Foreign-Born and Korean Nationals Living in the Republic of Korea, 2007-2016. Osong Public Health Res Perspect 2018; 9:126-129. [PMID: 30023158 PMCID: PMC6037399 DOI: 10.24171/j.phrp.2018.9.3.08] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Japanese encephalitis (JE) vaccine was introduced to the national immunization program in 1985, which has led to a dramatic decrease in the number of reported cases, but JE continues to occur in foreign nationals residing in or traveling to Korea. Although the incidence is low, this study demonstrated that more Koreans were infected with JE than foreign-born expatriates. The incidence rates of Korean-born nationals were between 0.01 and 0.08 cases per 100,000. In contrast, the incidence rates of foreign-born nationals ranged between 0 and 0.26 cases per 100,000. The incidence rates clearly showed that foreign-born expatriates were more at risk, which underscores the importance of vaccination. We recommend heightened surveillance among JE-susceptible individuals and promote vaccination among foreign-born nationals living in Korea.
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Affiliation(s)
- Een-Suk Shin
- Division of Risk Assessment & International Cooperation, Korea Centers for Disease Control and Prevention, Cheongju, Korea
| | - Ok Park
- Division of Risk Assessment & International Cooperation, Korea Centers for Disease Control and Prevention, Cheongju, Korea
| | - In-Sik Kong
- Division of Vaccine-Preventable Diseases Control and National Immunization Program, Korea Centers for Disease Control and Prevention, Cheongju, Korea
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20
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Li X, Gao X, Fu S, Wang H, Lu Z, He Y, Lei W, Liang G. An Outbreak of Japanese Encephalitis in Adults in Northern China, 2013: A Population-Based Study. Vector Borne Zoonotic Dis 2018; 19:26-34. [PMID: 29741995 DOI: 10.1089/vbz.2017.2251] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND A Japanese encephalitis (JE) epidemic occurred in 2013 in China. The aim of this study was to determine the spatial-temporal pattern of JE cases in adults occurring in 2013, as well as identify potential hotspots of incidences in the afflicted regions in China. METHODS/PRINCIPAL FINDINGS To generate a spatial-temporal pattern of JE cases in China, epidemiological and demographic data between 2011 and 2013 were collected. Our results indicate that the total number of JE cases in 2013 was significantly higher compared with those in 2011 and 2012. While the incidence of JE in individuals aged less than 15 years decreased in 2013, the incidence rate increased substantially in those aged 15 years and older. The population aged over 40 years was associated with the greatest increase of JE. Demographic analysis revealed a consistent increase in the proportion of JE cases aged 15 years and older in 2013 (42%) compared with that in 2012 (15%). In addition, JE cases from areas located between 35°N, 114°E and 40°N, 120°E in northern China were found to account for 27.17% of total JE cases nationwide in 2013, compared with 2.21% and 3.13% in 2011 and 2012, respectively. In these northern regions, the group aged 15 years and older represents the predominant population with JE, accounting for 73% of total cases. Further cluster analysis identified a large number of hotspots of JE in adults (>15 years of age) in northern China. CONCLUSIONS/SIGNIFICANCE Unlike the JE epidemics primarily in children below 15 years old in southern China, a significant outbreak of JE occurred in northern China in 2013, with the older age groups being the primary population affected. The increasing incidence of JE in adults has become an important public health issue and poses a new challenge to the successful prevention and control of JE in China, as well as other countries in East Asia.
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Affiliation(s)
- Xiaolong Li
- 1 State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,2 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Xiaoyan Gao
- 1 State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,2 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Shihong Fu
- 1 State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,2 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Huanyu Wang
- 1 State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,2 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Zhi Lu
- 1 State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,2 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Ying He
- 1 State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,2 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Wenwen Lei
- 1 State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,2 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Guodong Liang
- 1 State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,2 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
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Bae W, Kim JH, Kim J, Lee J, Hwang ES. Changes of Epidemiological Characteristics of Japanese Encephalitis Viral Infection and Birds as a Potential Viral Transmitter in Korea. J Korean Med Sci 2018; 33:e70. [PMID: 29441740 PMCID: PMC5811662 DOI: 10.3346/jkms.2018.33.e70] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 12/27/2017] [Indexed: 11/20/2022] Open
Abstract
Japanese encephalitis (JE) cases have been increasingly reported recently especially in Seoul and its vicinity. Pigs are known as amplifying host of JE virus (JEV), but do not play an important role in these recent events because pig-breeding is not common in Seoul. The distribution and the density of migratory birds are correlated with JE cases in cities and they might be highly potential hosts contributing to transmit JEV in metropolitan areas. JE genotype and sero-prevalence in birds should be determined for the verification of the transmission route of JEV in the recent sporadic occurrence of JE cases in Seoul.
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Affiliation(s)
- Wonjun Bae
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Korea
- Global Center for Infectious Diseases, Seoul National University College of Medicine, Seoul, Korea
| | - Jung Heon Kim
- Global Center for Infectious Diseases, Seoul National University College of Medicine, Seoul, Korea
- Institute of Endemic Disease, Seoul National University Medical Research Center, Seoul, Korea
| | - Jiyeon Kim
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Korea
- Global Center for Infectious Diseases, Seoul National University College of Medicine, Seoul, Korea
| | - Jungyun Lee
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Korea
- Global Center for Infectious Diseases, Seoul National University College of Medicine, Seoul, Korea
| | - Eung Soo Hwang
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, Korea
- Global Center for Infectious Diseases, Seoul National University College of Medicine, Seoul, Korea
- Institute of Endemic Disease, Seoul National University Medical Research Center, Seoul, Korea.
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22
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Sunwoo JS, Jung KH, Lee ST, Lee SK, Chu K. Reemergence of Japanese Encephalitis in South Korea, 2010-2015. Emerg Infect Dis 2018; 22:1841-3. [PMID: 27648677 PMCID: PMC5038436 DOI: 10.3201/eid2210.160288] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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23
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Choe YJ, Taurel AF, Nealon J, Seo HS, Kim HS. Systematic review of seroepidemiological studies on Japanese encephalitis in the Republic of Korea. Int J Infect Dis 2018; 67:14-19. [DOI: 10.1016/j.ijid.2017.11.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 11/18/2017] [Accepted: 11/21/2017] [Indexed: 11/30/2022] Open
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24
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Lin CL, Chang HL, Lin CY, Chen KT. Seasonal Patterns of Japanese Encephalitis and Associated Meteorological Factors in Taiwan. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:E1317. [PMID: 29109371 PMCID: PMC5707956 DOI: 10.3390/ijerph14111317] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 10/25/2017] [Accepted: 10/27/2017] [Indexed: 11/16/2022]
Abstract
The persistent transmission of Japanese encephalitis virus (JEV) in Taiwan necessitates exploring the risk factors of occurrence of Japanese encephalitis (JE). The purpose of this study was to assess the relationship between meteorological factors and the incidence of JE in Taiwan. We collected data for cases of JE reported to the Taiwan Centers for Disease Control (Taiwan CDC) from 2000 to 2014. Meteorological data were obtained from the Taiwan Central Weather Bureau. The relationships between weather variability and the incidence of JE in Taiwan were determined via Poisson regression analysis and a case-crossover methodology. During the 15-year study period, a total of 379 cases of JE were reported. The incidence of JE showed significant seasonality, with the majority of cases occurring in summertime (for oscillation, p < 0.001). The number of JE cases started to increase at temperatures of 22 °C (r² = 0.88, p < 0.001). Similarly, the number of JE cases began to increase at a relative humidity of 70-74% (r² = 0.75, p < 0.005). The number of JE cases was positively associated with mean temperature and relative humidity in the period preceding the infection. In conclusion, the occurrence of JE is significantly associated with increasing temperature and relative humidity in Taiwan. Therefore, these factors could be regarded as warning signals indicating the need to implement preventive measures.
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Affiliation(s)
- Che-Liang Lin
- Internal Medicine Chest Division, Chi-Mei Medical Center, Liouying, Tainan 736, Taiwan.
| | - Hsiao-Ling Chang
- Division of Infection Control and Biosafety, Centers for Disease Control, Ministry of Health and Welfare, Taipei 104, Taiwan.
- School of Public Health, National Defense Medical Center, National Defense University, Taipei 117, Taiwan.
| | - Chuan-Yao Lin
- Research Center for Environmental Changes, Academia Sinica, 115, Taiwan.
| | - Kow-Tong Chen
- Department of Occupational Medicine, Tainan Municipal Hospital (Managed by Show Chwan Medical Care Corporation), Tainan 701, Taiwan.
- Department of Public Health, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan.
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25
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Li GH, Ning ZJ, Liu YM, Li XH. Neurological Manifestations of Dengue Infection. Front Cell Infect Microbiol 2017; 7:449. [PMID: 29119088 PMCID: PMC5660970 DOI: 10.3389/fcimb.2017.00449] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 10/04/2017] [Indexed: 12/20/2022] Open
Abstract
Dengue counts among the most commonly encountered arboviral diseases, representing the fastest spreading tropical illness in the world. It is prevalent in 128 countries, and each year >2.5 billion people are at risk of dengue virus infection worldwide. Neurological signs of dengue infection are increasingly reported. In this review, the main neurological complications of dengue virus infection, such as central nervous system (CNS), peripheral nervous system, and ophthalmic complications were discussed according to clinical features, treatment and possible pathogenesis. In addition, neurological complications in children were assessed due to their atypical clinical features. Finally, dengue infection and Japanese encephalitis were compared for pathogenesis and main clinical manifestations.
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Affiliation(s)
- Guo-Hong Li
- Department of Neurology, Jinan Central Hospital Affiliated to Shandong University, Jinan, China
| | - Zhi-Jie Ning
- Jinan Infectious Diseases Hospital, Jinan, China
| | - Yi-Ming Liu
- Department of Neurology, Qilu Hospital, Shandong University, Jinan, China
| | - Xiao-Hong Li
- Department of Neurology, Jinan Central Hospital Affiliated to Shandong University, Jinan, China
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26
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Yoshii K, Song JY, Park SB, Yang J, Schmitt HJ. Tick-borne encephalitis in Japan, Republic of Korea and China. Emerg Microbes Infect 2017; 6:e82. [PMID: 28928417 PMCID: PMC5625319 DOI: 10.1038/emi.2017.69] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 06/29/2017] [Accepted: 07/09/2017] [Indexed: 12/18/2022]
Abstract
Tick-borne encephalitis virus (TBEV) causes mild or moderate febrile illness in humans that may progress to encephalitis, leading to severe long-term complications and sometimes death. TBEV is prevalent in the Eurasian continent and has been isolated in China, Japan and Republic of Korea (ROK). The TBEV isolates from Japan are of the Far-Eastern subtype; in ROK, the isolates are of the Western subtype; and all TBEV isolates in China are of the Far-Eastern subtype, except one strain that was identified most recently as the Siberian subtype. TBE is endemic to the northeast, northwest and southeast of China; only two confirmed TBE cases have been reported in Japan to date; and no TBE case has been confirmed in ROK. For TBE patients in China, the onset of disease is acute with no biphasic course for disease presentation. The clinical spectrum of disease phenotypes may be wider than currently understood, since serological evidence suggests the presence of TBEV infections in healthy people, indicating that asymptomatic or unspecific manifestations of TBEV infection may exist. The current treatment for TBE is supportive care. In China, vaccines against TBEV have been developed and are available with demonstrated immunogenicity and safety, although efficacy data are lacking. No vaccines are available in ROK or Japan.
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Affiliation(s)
- Kentaro Yoshii
- Laboratory of Public Health, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Joon Young Song
- Division of Infectious Diseases, Department of Internal Medicine, Korea University Guro Hospital, Gurodongro 148, Gurogu, Seoul 08308, Republic of Korea
| | - Seong-Beom Park
- Pfizer Pharmaceuticals Korea Ltd, Seoul 100-771, Republic of Korea
| | - Junfeng Yang
- Pfizer Investment Co., Ltd. The Fifth Square, Tower B, 9/F, No. 3-7, Chaoyangmen North Avenue, Dongcheng District, Beijing 100010, China
| | - Heinz-Josef Schmitt
- Scientific Affairs, Pfizer Vaccines Europe, 23-25 Avenue du Dr Lannelongue, Paris 75014, France
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27
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Sunwoo JS, Lee ST, Jung KH, Park KI, Moon J, Jung KY, Kim M, Lee SK, Chu K. Clinical Characteristics of Severe Japanese Encephalitis: A Case Series from South Korea. Am J Trop Med Hyg 2017; 97:369-375. [PMID: 28829730 DOI: 10.4269/ajtmh.17-0054] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Japanese encephalitis (JE) virus is a major cause of devastating viral encephalitis, especially in Asia. Although a successful vaccination program led to its near-elimination over three decades in South Korea, the incidence of JE has increased since 2010. The present study investigated the clinical manifestations, laboratory findings, and factors affecting neurological outcomes of reemerging JE. We retrospectively reviewed medical records of laboratory-confirmed JE patients who presented with acute encephalitis syndrome at three tertiary hospitals between 2010 and 2015. A total of 17 patients with JE were identified. Their median age was 51 years, and 10 (58.5%) were men. The most common symptoms and signs were fever (94.1%), altered consciousness (94.1%), and headache (80.2%). Hyporeflexia (47.1%), seizures (35.2%), abnormal brainstem reflex (23.5%), and flaccid weakness (17.6%) were also noted. Brain imaging revealed thalamic lesions in all patients, with the hippocampus, midbrain, basal ganglia, and cerebral cortex affected to varying degrees. Sixteen patients (94.1%) required management in the intensive care unit with mechanical ventilation due to neurological deterioration. At the time of discharge, 11 (64.7%) had poor recovery, defined as Glasgow coma scale scores of less than 8, and remained ventilator dependent. Comparison between the two outcome groups indicated that midbrain involvement (P = 0.028) and rapid deterioration (P = 0.005) were associated with severe neurological sequelae. Given that JE is a vaccine-preventable disease, vaccination for adults should be considered in response to the reemergence of JE.
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Affiliation(s)
- Jun-Sang Sunwoo
- Department of Neurology, Soonchunhyang University School of Medicine, Seoul, South Korea
| | - Soon-Tae Lee
- Program in Neuroscience, Seoul National University College of Medicine, Seoul, South Korea.,Department of Neurology, Comprehensive Epilepsy Center, Seoul National University Hospital, Seoul, South Korea
| | - Keun-Hwa Jung
- Program in Neuroscience, Seoul National University College of Medicine, Seoul, South Korea.,Department of Neurology, Comprehensive Epilepsy Center, Seoul National University Hospital, Seoul, South Korea
| | - Kyung-Il Park
- Department of Neurology, Seoul National University Hospital Healthcare System Gangnam Center, Seoul, South Korea
| | - Jangsup Moon
- Program in Neuroscience, Seoul National University College of Medicine, Seoul, South Korea.,Department of Neurology, Comprehensive Epilepsy Center, Seoul National University Hospital, Seoul, South Korea
| | - Ki-Young Jung
- Program in Neuroscience, Seoul National University College of Medicine, Seoul, South Korea.,Department of Neurology, Comprehensive Epilepsy Center, Seoul National University Hospital, Seoul, South Korea
| | - Manho Kim
- Protein Metabolism Medical Research Center, Seoul National University College of Medicine, Seoul, South Korea.,Program in Neuroscience, Seoul National University College of Medicine, Seoul, South Korea.,Department of Neurology, Comprehensive Epilepsy Center, Seoul National University Hospital, Seoul, South Korea
| | - Sang Kun Lee
- Program in Neuroscience, Seoul National University College of Medicine, Seoul, South Korea.,Department of Neurology, Comprehensive Epilepsy Center, Seoul National University Hospital, Seoul, South Korea
| | - Kon Chu
- Department of Neurology, Comprehensive Epilepsy Center, Seoul National University Hospital, Seoul, South Korea.,Program in Neuroscience, Seoul National University College of Medicine, Seoul, South Korea
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28
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Connor B, Bunn WB. The changing epidemiology of Japanese encephalitis and New data: the implications for New recommendations for Japanese encephalitis vaccine. TROPICAL DISEASES TRAVEL MEDICINE AND VACCINES 2017; 3:14. [PMID: 28883984 PMCID: PMC5537987 DOI: 10.1186/s40794-017-0057-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 07/11/2017] [Indexed: 11/10/2022]
Abstract
The epidemiology of Japanese Encephalitis and risk to the traveler has changed and continues to evolve. The spread of Japanese Encephalitis virus into new environments, changes in agricultural practice and animal vectors, climate change, peri-urban growth, changes in international travel to Asia, personal risk factors, mosquito vector free transmission, interactions with other flaviviruses and better information on infections without encephalitis and other factors make Japanese Encephalitis an underappreciated risk. There has also been a change in the incidence of Japanese Encephalitis cases that questions the current travel duration and geographic based recommendations. A safe, effective vaccine (Ixiaro) that may be administered in a short course regimen is now available in the United States without the risks of the previous vaccine. However, the vaccine is significantly underutilized. These changes in the epidemiology and new data on the risks of the Japanese Encephalitis virus require a review of the practice guidelines and expert recommendations that do not reflect the current state of knowledge.
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Affiliation(s)
- Bradley Connor
- The New York Center for Travel and Tropical Medicine, Weill Medical College of Cornell University, 110 East 55th Street, 16th Floor, New York, NY 10022 USA
| | - William B Bunn
- Medical University of South Carolina, University of Illinois at Chicago School of Public Health, Chicago, USA
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29
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Chang YK, Chang HL, Wu HS, Chen KT. Epidemiological Features of Japanese Encephalitis in Taiwan from 2000 to 2014. Am J Trop Med Hyg 2016; 96:382-388. [PMID: 27821699 DOI: 10.4269/ajtmh.16-0330] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 09/20/2016] [Indexed: 11/07/2022] Open
Abstract
The incidence of Japanese encephalitis (JE) decreased sharply after the national vaccination program was implemented in Taiwan in 1968. However, cases of JE still occur. The purpose of this study was to assess the epidemiology and vaccination policy for JE in Taiwan. We analyzed the data on JE cases reported to the Taiwan Centers for Disease Control (Taiwan CDC) between 2000 and 2014. During the 15-year study period, a total of 4,474 cases were reported to the Taiwan CDC. Of these, 379 (8.5%) were classified as confirmed cases, and 4,095 (91.5%) were classified as suspected cases. The incidence of JE ranged from 0.59 to 1.61 per 1,000,000 people and peaked in 2007. Men had a higher incidence of JE than women (1.37 versus 0.84 per 1,000,000; P = 0.03). Patients who were 40-59 years of age had a higher incidence than did patients younger than 20 years (1.82 versus 0.23; P < 0.001). Patients who lived in the eastern region of Taiwan had the highest incidence rate of JE (P < 0.001). Compared with those who were not vaccinated with the JE vaccine, patients who received four doses of JE vaccine had a lower risk of suffering from death and/or hospitalization (adjusted odds ratio: 0.26; 95% confidence interval: 0.08-0.90; P = 0.04). JE is still a public health problem in Taiwan, and monitoring JE via diagnostic testing to determine the best vaccination program along with enforcing JE vaccine boosters for adults is necessary to eliminate JE in Taiwan.
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Affiliation(s)
- Yu-Kang Chang
- Department of Radiology, Liouying Campus, Chi-Mei Medical Center, Tainan, Taiwan
| | - Hsiao-Ling Chang
- Division of Infection Control and Biosafety, Centers for Disease Control, Ministry of Health and Welfare, Taipei, Taiwan.,School Public Health, National Defense Medical Center, National Defense University, Taipei, Taiwan
| | - Ho-Sheng Wu
- Hsinchu Blood Center, Taiwan Blood Services Foundation, Hsinchu, Taiwan.,School of Medical Laboratory Science and Biotechnology, Taipei Medical University, Taipei, Taiwan
| | - Kow-Tong Chen
- Department of Occupational Medicine, Tainan Municipal Hospital, Tainan, Taiwan. .,Department of Public Health, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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30
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Li X, Cui S, Gao X, Wang H, Song M, Li M, Fu S, Lv Z, He Y, Lei W, Wang B, Lu X, Liang G. The Spatio-temporal Distribution of Japanese Encephalitis Cases in Different Age Groups in Mainland China, 2004 - 2014. PLoS Negl Trop Dis 2016; 10:e0004611. [PMID: 27050414 PMCID: PMC4822867 DOI: 10.1371/journal.pntd.0004611] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 03/15/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Japanese encephalitis (JE) is very prevalent in China, but the incidence of JE among children has been greatly reduced by extensive promotion of vaccinations. The incidence of JE among adults, however, has increased in some parts of China. METHODS/PRINCIPAL FINDINGS Data on JE in mainland China, in terms of incidence, gender, and age, were collected between 2004 and 2014. We conducted spatial and temporal analyses on data from different age groups. Generally, children aged 0-15 years still represent the major population of JE cases in China, despite the gradual decrease in incidence over years. However, the incidence of JE among adults in several provinces is notably higher than the national average, especially during the epidemic waves in 2006, 2009, and 2013. The JE cases in the 0-15-year-old group are distributed mainly in the area south of the Yangtze River, with peak incidence occurring from July to September. In the adult group, especially for those over 40 years old, the JE cases are concentrated mainly in the area north of the Yangtze River. JE incidence in the adult group in September and October is significantly greater compared to the other groups. Further analysis using Local Indicators of Spatial Association (LISA) reveals that the distribution of adult JE cases in the six provinces north of the Yangtze River, between north 30-35° latitude and east 110-130° longitude, is a hotspot for adult JE cases. CONCLUSIONS/SIGNIFICANCE The rate of JE case increase for adults is much greater than for children and has become a public health issue. Therefore, studies on the necessity and feasibility of vaccinating adults who live in JE-endemic areas, but have never been vaccinated for JE, should become a new focus of JE prevention in the future.
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Affiliation(s)
- Xiaolong Li
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Shiheng Cui
- Public Health Institute of Qingdao University, Qingdao, China
| | - Xiaoyan Gao
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Huanyu Wang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Miao Song
- Liupanshui Vocational and Technical College, Liupanshui, Guizhou, China
| | - Minghua Li
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Shihong Fu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Zhi Lv
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Ying He
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Wenwen Lei
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
| | - Bin Wang
- Public Health Institute of Qingdao University, Qingdao, China
| | - Xiaoqing Lu
- Public Health Institute of Qingdao University, Qingdao, China
- * E-mail: (GL); (XL)
| | - Guodong Liang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People’s Republic of China
- * E-mail: (GL); (XL)
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Immunogenicity and Safety of a Booster Dose of a Live Attenuated Japanese Encephalitis Chimeric Vaccine Given 1 Year After Primary Immunization in Healthy Children in the Republic of Korea. Pediatr Infect Dis J 2016; 35:e60-4. [PMID: 26535878 DOI: 10.1097/inf.0000000000000967] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND This study evaluated the effect of a booster vaccination of a new, live attenuated, Japanese encephalitis chimeric vaccine (JE-CV). Previously this vaccine has been used as a booster 12 months after priming with an inactivated vaccine and at >24 months after priming with the same JE-CV. This study evaluates the immunogenicity and safety of the JE-CV given at 12-24 months after JE-CV priming. METHODS Phase III, open-label study in the Republic of Korea in which 119 children previously vaccinated with JE-CV at 12-24 months of age received a JE-CV booster at 12-24 months after primary vaccination. JE neutralizing antibody titers were measured using >50% plaque reduction neutralization test prebooster and 1 month postbooster vaccination. Seroprotection (SP) was defined as ≥10 (1/dil). Safety was assessed for 28 days postvaccination by parental reports. Serious adverse events were monitored for 6 months postvaccination. RESULTS Antibody persistence was high prebooster (SP rate 93.5%). There was a strong anamnestic response postbooster vaccination, with an SP rate of 100% and a >50-fold increase in geometric mean titer from the prebooster level. Both antibody persistence and the booster response were independent of whether the booster was given at 12-17 or 18-24 months. The safety profile was good and comparable with the primary vaccination; there were no vaccine-related serious adverse events and no deaths. CONCLUSIONS This study confirms the suitability of a JE-CV booster vaccination at 12-24 months after a primary dose of the same vaccine given at 12-24 months of age in children in the Republic of Korea.
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32
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Lee EJ, Cha GW, Ju YR, Han MG, Lee WJ, Jeong YE. Prevalence of Neutralizing Antibodies to Japanese Encephalitis Virus among High-Risk Age Groups in South Korea, 2010. PLoS One 2016; 11:e0147841. [PMID: 26807709 PMCID: PMC4725746 DOI: 10.1371/journal.pone.0147841] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 01/08/2016] [Indexed: 11/30/2022] Open
Abstract
After an extensive vaccination policy, Japanese encephalitis (JE) was nearly eliminated since the mid-1980s in South Korea. Vaccination in children shifted the affected age of JE patients from children to adults. However, an abrupt increase in JE cases occurred in 2010, and this trend has continued. The present study aimed to investigate the prevalence of neutralizing antibodies to the JE virus (JEV) among high-risk age groups (≥40 years) in South Korea. A plaque reduction neutralization test was conducted to evaluate the prevalence of neutralizing antibodies to JEV in 945 subjects within four age groups (30–39, 40–49, 50–59, and 60–69 years) in 10 provinces. Of the 945 enrolled subjects, 927 (98.1%) exhibited antibodies against JEV. No significant differences were found in the prevalence of neutralizing antibodies according to sex, age, or occupation. However, there were significant differences in the plaque reduction rate according to age and occupation; oldest age group had a higher reduction rate, and subjects who were employed in agriculture or forestry also had a higher value than the other occupations. We also found that three provinces (Gangwon, Jeonnam, and Gyeongnam) had a relatively lower plaque reduction rate than the other locations. In addition, enzyme-linked immunosorbent assays were conducted to determine recent viral infections and 12 (2.2%) subjects were found to have been recently infected by the virus. In conclusion, the present study clearly indicated that the prevalence of neutralizing antibodies has been maintained at very high levels among adult age groups owing to vaccination or natural infections, or both. In the future, serosurveillance should be conducted periodically using more representative samples to better understand the population-level immunity to JE in South Korea.
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Affiliation(s)
- Eun Ju Lee
- Division of Arboviruses, National Institute of Health, Korea Centers for Disease Control and Prevention, Cheongju-si, Chungcheongbuk-do, Korea
- Japanese Encephalitis Regional Reference Laboratory for the WHO Western Pacific Region, Cheongju-si, Chungcheongbuk-do, Korea
| | - Go-Woon Cha
- Division of Arboviruses, National Institute of Health, Korea Centers for Disease Control and Prevention, Cheongju-si, Chungcheongbuk-do, Korea
- Japanese Encephalitis Regional Reference Laboratory for the WHO Western Pacific Region, Cheongju-si, Chungcheongbuk-do, Korea
| | - Young Ran Ju
- Division of Arboviruses, National Institute of Health, Korea Centers for Disease Control and Prevention, Cheongju-si, Chungcheongbuk-do, Korea
- Japanese Encephalitis Regional Reference Laboratory for the WHO Western Pacific Region, Cheongju-si, Chungcheongbuk-do, Korea
| | - Myung Guk Han
- Division of Arboviruses, National Institute of Health, Korea Centers for Disease Control and Prevention, Cheongju-si, Chungcheongbuk-do, Korea
- Japanese Encephalitis Regional Reference Laboratory for the WHO Western Pacific Region, Cheongju-si, Chungcheongbuk-do, Korea
| | - Won-Ja Lee
- Division of Arboviruses, National Institute of Health, Korea Centers for Disease Control and Prevention, Cheongju-si, Chungcheongbuk-do, Korea
- Japanese Encephalitis Regional Reference Laboratory for the WHO Western Pacific Region, Cheongju-si, Chungcheongbuk-do, Korea
| | - Young Eui Jeong
- Division of Arboviruses, National Institute of Health, Korea Centers for Disease Control and Prevention, Cheongju-si, Chungcheongbuk-do, Korea
- Japanese Encephalitis Regional Reference Laboratory for the WHO Western Pacific Region, Cheongju-si, Chungcheongbuk-do, Korea
- Department of Biomedical Sciences, Graduate School of Hallym University, Chuncheon-si, Gangwon-do, Korea
- * E-mail:
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Lancaster E. The Diagnosis and Treatment of Autoimmune Encephalitis. J Clin Neurol 2016; 12:1-13. [PMID: 26754777 PMCID: PMC4712273 DOI: 10.3988/jcn.2016.12.1.1] [Citation(s) in RCA: 258] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Revised: 10/02/2015] [Accepted: 10/03/2015] [Indexed: 12/31/2022] Open
Abstract
Autoimmune encephalitis causes subacute deficits of memory and cognition, often followed by suppressed level of consciousness or coma. A careful history and examination may show early clues to particular autoimmune causes, such as neuromyotonia, hyperekplexia, psychosis, dystonia, or the presence of particular tumors. Ancillary testing with MRI and EEG may be helpful for excluding other causes, managing seizures, and, rarely, for identifying characteristic findings. Appropriate autoantibody testing can confirm specific diagnoses, although this is often done in parallel with exclusion of infectious and other causes. Autoimmune encephalitis may be divided into several groups of diseases: those with pathogenic antibodies to cell surface proteins, those with antibodies to intracellular synaptic proteins, T-cell diseases associated with antibodies to intracellular antigens, and those associated with other autoimmune disorders. Many forms of autoimmune encephalitis are paraneoplastic, and each of these conveys a distinct risk profile for various tumors. Tumor screening and, if necessary, treatment is essential to proper management. Most forms of autoimmune encephalitis respond to immune therapies, although powerful immune suppression for weeks or months may be needed in difficult cases. Autoimmune encephalitis may relapse, so follow-up care is important.
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Affiliation(s)
- Eric Lancaster
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA.
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Chokephaibulkit K, Houillon G, Feroldi E, Bouckenooghe A. Safety and immunogenicity of a live attenuated Japanese encephalitis chimeric virus vaccine (IMOJEV®) in children. Expert Rev Vaccines 2015; 15:153-66. [PMID: 26588242 DOI: 10.1586/14760584.2016.1123097] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
JE-CV (IMOJEV®, Sanofi Pasteur, France) is a live attenuated virus vaccine constructed by inserting coding sequences of the prM and E structural proteins of the Japanese encephalitis SA14-14-2 virus into the genome of yellow fever 17D virus. Primary immunization with JE-CV requires a single dose of the vaccine. This article reviews clinical trials of JE-CV in children aged up to 6 years conducted in countries across South-East Asia. Strong and persistent antibody responses were observed after single primary and booster doses, with 97% of children seroprotected up to five years after booster vaccination. Models of long-term antibody persistence predict a median duration of protection of approximately 30 years after a booster dose. The safety and reactogenicity profiles of JE-CV primary and booster doses are comparable to other widely used childhood vaccines.
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Affiliation(s)
- K Chokephaibulkit
- a Department of Pediatrics, Faculty of Medicine Siriraj Hospital , Mahidol University , Bangkok , Thailand
| | - G Houillon
- b Global Medical Affairs , Sanofi Pasteur , Lyon , France
| | - E Feroldi
- c Clinical Development , Sanofi Pasteur , Lyon , France
| | - A Bouckenooghe
- d Asia Regional Medical Affairs and Clinical Development , Sanofi Pasteur , Singapore
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Erra EO, Kantele A. The Vero cell-derived, inactivated, SA14-14-2 strain-based vaccine (Ixiaro) for prevention of Japanese encephalitis. Expert Rev Vaccines 2015; 14:1167-79. [PMID: 26162529 DOI: 10.1586/14760584.2015.1061939] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
With an estimated 68,000 cases each year, Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia. Vaccination against the disease is recommended for endemic populations and also for travelers at risk. Recently, a Vero cell-derived, inactivated, SA14-14-2 strain-based JE vaccine (JE-VC) became available for travelers from non-endemic regions, replacing the traditional mouse brain-derived vaccines. First licensed in 2009, JE-VC is currently available in Europe, the USA, Canada, Australia and several other countries. In 2013, the vaccine was approved by the European Medicines Agency and the US Food and Drug Administration for use in children. This review summarizes current data on the immunogenicity, safety and clinical use of JE-VC.
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Affiliation(s)
- Elina O Erra
- Haartman Institute, University of Helsinki, Helsinki, Finland
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Ishikawa T, Konishi E. Potential chemotherapeutic targets for Japanese encephalitis: current status of antiviral drug development and future challenges. Expert Opin Ther Targets 2015; 19:1379-95. [PMID: 26156208 DOI: 10.1517/14728222.2015.1065817] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Japanese encephalitis (JE) remains a public health threat in Asia. Although several vaccines have been licensed, ∼ 67,900 cases of the disease are estimated to occur annually, probably because the vaccine coverage is low. Therefore, effective antiviral drugs are required to control JE. However, no licensed anti-JE drugs are available, despite extensive efforts to develop them. AREAS COVERED We provide a general overview of JE and JE virus, including its transmission cycle, distribution, structure, replication machinery, immune evasion mechanisms and vaccines. The current situation in antiviral drug development is then reviewed and future perspectives are discussed. EXPERT OPINION Although the development of effective anti-JE drugs is an urgent issue, only supportive care is currently available. Recent progress in our understanding of the viral replication machinery and immune evasion strategies has identified new targets for anti-JE drug development. To date, most candidate drugs have only been evaluated in single-drug formulations, and efficient drug delivery to the CNS has virtually not been considered. However, an effective anti-JE treatment is expected to be achieved with multiple-drug formulations and a targeted drug delivery system in the near future.
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Affiliation(s)
- Tomohiro Ishikawa
- a 1 Dokkyo Medical University, School of Medicine, Department of Microbiology , 880 Kitakobayashi, Mibu-machi, Shimotsuga-gun, Tochigi 321-0293, Japan
| | - Eiji Konishi
- b 2 Mahidol University, BIKEN Endowed Department of Dengue Vaccine Development, Faculty of Tropical Medicine , 420/6 Ratchawithi Road, Ratchathewi, Bangkok 10400, Thailand.,c 3 Osaka University, Research Institute for Microbial Diseases, BIKEN Endowed Department of Dengue Vaccine Development , 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan +66 2 354 5981 ;
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Wang H, Liang G. Epidemiology of Japanese encephalitis: past, present, and future prospects. Ther Clin Risk Manag 2015; 11:435-48. [PMID: 25848290 PMCID: PMC4373597 DOI: 10.2147/tcrm.s51168] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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.
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Affiliation(s)
- Huanyu Wang
- State Key Laboratory for Infectious Disease Prevention and Control (SKLID), Department of Viral Encephalitis, Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing People's Republic of China ; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China
| | - Guodong Liang
- State Key Laboratory for Infectious Disease Prevention and Control (SKLID), Department of Viral Encephalitis, Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing People's Republic of China ; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China
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Kim H, Cha GW, Jeong YE, Lee WG, Chang KS, Roh JY, Yang SC, Park MY, Park C, Shin EH. Detection of Japanese encephalitis virus genotype V in Culex orientalis and Culex pipiens (Diptera: Culicidae) in Korea. PLoS One 2015; 10:e0116547. [PMID: 25658839 PMCID: PMC4319795 DOI: 10.1371/journal.pone.0116547] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 10/24/2014] [Indexed: 11/18/2022] Open
Abstract
Japanese encephalitis virus (JEV) causes significant viral encephalitis and is distributed throughout the Asian countries. The virus is known to be transmitted by Culex tritaeniorhynchus, which mainly breeds in rice paddies in Korea. In this study, we investigated the presence of other mosquito species that can transmit JEV as a second or regional vector. We selected five cities where patients have experienced JE in the last 5 years as mosquito-collecting locations and subdivided them into four collection sites according to the mosquito habitats (cowshed, downtown area, forest, and swamp). Mosquitoes were caught using the BG-Sentinel trap, CDC black-light trap, Fay-Prince trap, and Gravid trap. A total of 993 pools from 22,774 mosquitoes were prepared according to their species, collection date, and site. We performed a SYBR Green 1-based real-time RT-PCR assay to detect JEV from the mosquito pools. A total of six JEV-positive pools were detected from Culex orientalis and Culex pipiens caught in the Gangwon-do and Gyeonngi-do provinces. All the detected JEVs were revealed as genotype V by phylogenetic analysis of the envelope gene. Our findings confirm that a new genotype of JEV was introduced in Korea and suggest that two mosquito species may play a role in JEV transmission.
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Affiliation(s)
- Hyunwoo Kim
- Division of Medical Entomology, Center for Immunology and Pathology, Korea National Institute of Health, Cheongju, South Korea
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Go-Woon Cha
- Division of Arboviruses, Center for Immunology and Pathology, Korea National Institute of Health, Cheongju, South Korea
| | - Young Eui Jeong
- Division of Arboviruses, Center for Immunology and Pathology, Korea National Institute of Health, Cheongju, South Korea
- Department of Biomedical Sciences, Graduate School of Hallym University, Chuncheon, South Korea
| | - Wook-Gyo Lee
- Division of Medical Entomology, Center for Immunology and Pathology, Korea National Institute of Health, Cheongju, South Korea
| | - Kyu Sik Chang
- Division of Medical Entomology, Center for Immunology and Pathology, Korea National Institute of Health, Cheongju, South Korea
| | - Jong Yul Roh
- Division of Medical Entomology, Center for Immunology and Pathology, Korea National Institute of Health, Cheongju, South Korea
| | - Sung Chan Yang
- Division of Medical Entomology, Center for Immunology and Pathology, Korea National Institute of Health, Cheongju, South Korea
| | - Mi Yeoun Park
- Division of Medical Entomology, Center for Immunology and Pathology, Korea National Institute of Health, Cheongju, South Korea
| | - Chan Park
- Division of Arboviruses, Center for Immunology and Pathology, Korea National Institute of Health, Cheongju, South Korea
| | - E-Hyun Shin
- Division of Medical Entomology, Center for Immunology and Pathology, Korea National Institute of Health, Cheongju, South Korea
- * E-mail:
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Daep CA, Muñoz-Jordán JL, Eugenin EA. Flaviviruses, an expanding threat in public health: focus on dengue, West Nile, and Japanese encephalitis virus. J Neurovirol 2014; 20:539-60. [PMID: 25287260 PMCID: PMC4331079 DOI: 10.1007/s13365-014-0285-z] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 08/01/2014] [Accepted: 08/26/2014] [Indexed: 10/24/2022]
Abstract
The flaviviruses dengue, West Nile, and Japanese encephalitis represent three major mosquito-borne viruses worldwide. These pathogens impact the lives of millions of individuals and potentially could affect non-endemic areas already colonized by mosquito vectors. Unintentional transport of infected vectors (Aedes and Culex spp.), traveling within endemic areas, rapid adaptation of the insects into new geographic locations, climate change, and lack of medical surveillance have greatly contributed to the increase in flaviviral infections worldwide. The mechanisms by which flaviviruses alter the immune and the central nervous system have only recently been examined despite the alarming number of infections, related deaths, and increasing global distribution. In this review, we will discuss the expansion of the geographic areas affected by flaviviruses, the potential threats to previously unaffected countries, the mechanisms of pathogenesis, and the potential therapeutic interventions to limit the devastating consequences of these viruses.
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Affiliation(s)
- Carlo Amorin Daep
- Public Health Research Institute (PHRI), Rutgers New Jersey Medical School, Rutgers the State University of New Jersey, Newark, NJ, USA
- Department of Microbiology and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers the State University of New Jersey, Newark, NJ, USA
| | - Jorge L. Muñoz-Jordán
- Centers for Disease Control and Prevention Dengue Branch, 1324 Cañada Street, San Juan, PR 00971
| | - Eliseo Alberto Eugenin
- Public Health Research Institute (PHRI), Rutgers New Jersey Medical School, Rutgers the State University of New Jersey, Newark, NJ, USA
- Department of Microbiology and Molecular Genetics, Rutgers New Jersey Medical School, Rutgers the State University of New Jersey, Newark, NJ, USA
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Kim DS, Houillon G, Jang GC, Cha SH, Choi SH, Lee J, Kim HM, Kim JH, Kang JH, Kim JH, Kim KH, Kim HS, Bang J, Naimi Z, Bosch-Castells V, Boaz M, Bouckenooghe A. A randomized study of the immunogenicity and safety of Japanese encephalitis chimeric virus vaccine (JE-CV) in comparison with SA14-14-2 vaccine in children in the Republic of Korea. Hum Vaccin Immunother 2014; 10:2656-63. [PMID: 25483480 PMCID: PMC4977450 DOI: 10.4161/hv.29743] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
A new live attenuated Japanese encephalitis chimeric virus vaccine (JE-CV) has been developed based on innovative technology to give protection against JE with an improved immunogenicity and safety profile. In this phase 3, observer-blind study, 274 children aged 12−24 months were randomized 1:1 to receive one dose of JE-CV (Group JE-CV) or the SA14–14–2 vaccine currently used to vaccinate against JE in the Republic of Korea (Group SA14–14–2). JE neutralizing antibody titers were assessed using PRNT50 before and 28 days after vaccination. The primary endpoint of non-inferiority of seroconversion rates on D28 was demonstrated in the Per Protocol analysis set as the difference between Group JE-CV and Group SA14–14–2 was 0.9 percentage points (95% confidence interval [CI]: −2.35; 4.68), which was above the required −10%. Seroconversion and seroprotection rates 28 days after administration of a single vaccine dose were 100% in Group JE-CV and 99.1% in Group SA14–14–2; all children except one (Group SA14–14–2) were seroprotected. Geometric mean titers (GMTs) increased in both groups from D0 to D28; GM of titer ratios were slightly higher in Group JE-CV (182 [95% CI: 131; 251]) than Group SA14–14–2 (116 [95% CI: 85.5, 157]). A single dose of JE-CV was well tolerated and no safety concerns were identified. In conclusion, a single dose of JE-CV or SA14–14–2 vaccine elicited a comparable immune response with a good safety profile. Results obtained in healthy Korean children aged 12−24 months vaccinated with JE-CV are consistent with those obtained in previous studies conducted with JE-CV in toddlers.
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Key Words
- AE, adverse event
- AESI, AE of Special Interest
- AR, adverse reaction
- CI, confidence interval
- FAS, Full Analysis Set
- GMT, Geometric mean titers
- GMTRs, GM of titer ratios
- JE, Japanese encephalitis
- JE-CV, JE chimeric virus vaccine
- JEV, JE virus
- Japanese encephalitis (JE) vaccine
- MBDV, mouse brain derived inactivated anti-JE vaccines
- PP, Per Protocol
- PRNT50, 50% plaque reduction neutralization test
- Phase 3 trial
- SAE, serious adverse events.
- children
- immunogenicity
- safety
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Affiliation(s)
- Dong Soo Kim
- a Yonsei University College of Medicine; Severance Children's Hospital ; Seoul , Korea
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Hills SL, Stoltey J, Martínez D, Kim PY, Sheriff H, Zangeneh A, Eilerman SR, Fischer M. A case series of three US adults with Japanese encephalitis, 2010-2012. J Travel Med 2014; 21:310-3. [PMID: 24861145 PMCID: PMC4594826 DOI: 10.1111/jtm.12127] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 02/10/2014] [Accepted: 02/19/2014] [Indexed: 11/27/2022]
Abstract
BACKGROUND Japanese encephalitis (JE) virus is the leading cause of vaccine-preventable encephalitis in Asia. Although the risk for acquiring JE for most travelers to Asia is low, it varies based on the destination, season, trip duration, and activities. METHODS We present case reports of three US adults who were infected with JE virus while traveling or residing in Asia. RESULTS Among the three JE patients, the first made a 10-day trip to mainland China and participated in outdoor activities in a rural area, the second had been resident in Taiwan for 4 months, and the third, fatal case was an expatriate living in South Korea. CONCLUSIONS JE should be considered in the differential diagnosis for any patient with an acute neurologic infection, who has recently been in a JE-endemic country. Health-care providers should assess the itineraries of travelers to JE-endemic countries, provide guidance on personal protective measures to prevent vector-borne diseases, and consider recommending JE vaccine for travelers at increased risk for JE virus infection.
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Affiliation(s)
- Susan L Hills
- Arboviral Diseases Branch, Centers for Disease Control and Prevention, Fort Collins, CO, USA
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Hsu LC, Chen YJ, Hsu FK, Huang JH, Chang CM, Chou P, Lin IF, Chang FY. The incidence of Japanese encephalitis in Taiwan--a population-based study. PLoS Negl Trop Dis 2014; 8:e3030. [PMID: 25058573 PMCID: PMC4109885 DOI: 10.1371/journal.pntd.0003030] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 06/05/2014] [Indexed: 11/18/2022] Open
Abstract
Background A mass Japanese encephalitis (JE) vaccination program targeting children was launched in Taiwan in 1968, and the number of pediatric JE cases substantially decreased thereafter. The aim of this study was to elucidate the long-term trend of JE incidence, and to investigate the age-specific seroprevalence of JE-neutralizing antibodies. Methodology/Principal Findings A total of 2,948 laboratory-confirmed JE cases that occurred between 1966 and 2012 were analyzed using a mandatory notification system managed by the Centers for Disease Control, Taiwan. A total of 6,594 randomly-sampled serum specimens obtained in a nationwide population-based survey in 2002 were analyzed to estimate the seroprevalence of JE-neutralizing antibodies in the general population. The average annual JE incidence rate of the group aged 30 years and older was 0.167 cases per 100,000 people between 2001 and 2012, which was higher than the 0.052 cases per 100,000 people among those aged under 30 years. These seroepidemiological findings indicate that the cohort born between 1963 and 1975, who generally received two or three doses of the vaccine and were administered the last booster dose more than 20 years ago, exhibited the lowest positive rate of JE-neutralizing antibodies (54%). The highest and second highest antibody rates were observed, respectively, in the oldest unvaccinated cohort (86%) and in the youngest cohort born between 1981 and 1986, who received four doses 10–15 years ago (74%). Conclusion/Significance Over the past decade, the main age group of the confirmed JE cases in Taiwan shifted from young children to adults over 30 years of age. People who were born between 1963 and 1975 exhibited the lowest seroprevalence of JE-neutralizing antibodies. Thus, the key issue for JE control in Taiwan is to reduce adult JE cases through a cost-effective analysis of various immunization strategies. JE is one of the major public health problems in Asian and the Western Pacific regions, and most cases occur in children under the age of 14 years. A JE virus infection can cause severe sequelae such as an impairment of language ability, cognitive ability, or movement. Because humans are a dead-end host of the JE virus, the disease cannot be transmitted among people. Vaccination is currently the most effective method for preventing JE, and children in most endemic areas are vaccinated. After decades of mass vaccination, the number of confirmed JE cases has considerably declined in Taiwan, Japan, and South Korea. Most JE cases have occurred in adults rather than children in these countries, thus, the disease must be controlled by reducing the number of adult JE cases. Therefore, a prevention policy for the adult and elderly population should be implemented in the near future.
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Affiliation(s)
- Li-Ching Hsu
- Center for Research, Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taipei, Taiwan, Republic of China
- Institute of Public Health, School of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China
| | - Yu-Ju Chen
- Center for Research, Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taipei, Taiwan, Republic of China
| | - Feng-Kuang Hsu
- Center for Research, Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taipei, Taiwan, Republic of China
| | - Jyh-Hsiung Huang
- Center for Research, Diagnostics and Vaccine Development, Centers for Disease Control, Ministry of Health and Welfare, Taipei, Taiwan, Republic of China
| | - Chi-Ming Chang
- Epidemic Intelligence Center, Centers for Disease Control, Ministry of Health and Welfare, Taipei, Taiwan, Republic of China
| | - Pesus Chou
- Institute of Public Health, School of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China
- Community Medicine Research Center, National Yang-Ming University, Taipei, Taiwan, Republic of China
| | - I-Feng Lin
- Institute of Public Health, School of Medicine, National Yang-Ming University, Taipei, Taiwan, Republic of China
- * E-mail: (IFL); (FYC)
| | - Feng-Yee Chang
- Centers for Disease Control, Ministry of Health and Welfare, Taipei, Taiwan, Republic of China
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China
- * E-mail: (IFL); (FYC)
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Duffy MR, Reed C, Edelson PJ, Blumensaadt S, Crocker K, Griggs A, Biggerstaff BJ, Delorey MJ, Hayes EB, Fischer M. A survey of US travelers to Asia to assess compliance with recommendations for the use of Japanese encephalitis vaccine. J Travel Med 2013; 20:165-70. [PMID: 23577862 PMCID: PMC5659122 DOI: 10.1111/jtm.12020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 11/02/2012] [Accepted: 11/27/2012] [Indexed: 10/27/2022]
Abstract
BACKGROUND Japanese encephalitis (JE) vaccine is recommended for travelers to Asia whose itineraries increase their risk of exposure to JE virus. The numbers of travelers with such itineraries and the proportion of those who receive JE vaccine are unknown. We performed a survey to estimate the proportion of US travelers to Asia who receive JE vaccine according to the Advisory Committee on Immunization Practices (ACIP) recommendations. METHODS We surveyed US residents ≥ 18 years old departing on 38 flights to Asia selected through a stratified random sample of all direct flights to JE-endemic countries from three US airports. We asked participants about planned itineraries and activities, sources of travel health information, JE vaccination status, and potential barriers to vaccination. Participants planning to spend ≥ 30 days in Asia or at least half of their time in rural areas were defined as "higher JE risk" travelers for whom vaccination should have been considered. RESULTS Of 2,341 eligible travelers contacted, 1,691(72%) completed the survey. Among these 1,691 participants, 415 (25%) described itineraries for which JE vaccination should have been considered. Of these 415 higher JE risk travelers, only 47 (11%) reported receiving ≥ 1 dose of JE vaccine. Of the 164 unvaccinated higher JE risk travelers who visited a health care provider before their trip, 113 (69%) indicated that they had never heard of JE vaccine or their health care provider had not offered or recommended JE vaccine. CONCLUSIONS A quarter of surveyed US travelers to Asia reported planned itineraries for which JE vaccination should have been considered. However, few of these at-risk travelers received JE vaccine.
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Affiliation(s)
- Mark R Duffy
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO 80521, USA
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