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Fujii M, Ito S, Katsumata E, Chambers JK, Matsugo H, Takenaka-Uema A, Murakami S, Uchida K, Horimoto T. Japanese Encephalitis Virus and Schizophyllum commune Co-Infection in a Harbor Seal in Japan. Vet Sci 2024; 11:215. [PMID: 38787188 PMCID: PMC11125775 DOI: 10.3390/vetsci11050215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 05/09/2024] [Accepted: 05/09/2024] [Indexed: 05/25/2024] Open
Abstract
The Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, has a wide host range, extending from pigs and ardeid birds to opportunistic dead-end hosts, such as humans and horses. However, JEV encephalitis infections in aquatic mammals are rare, with only two cases in seals reported to date. Here, we report a lethal case of JEV and Schizophyllum commune co-infection in an aquarium-housed harbor seal in Japan. We isolated JEV from the brain of the dead seal and characterized its phylogeny and pathogenicity in mice. The virus isolate from the seal was classified as genotype GIb, which aligns with recent Japanese human and mosquito isolates as well as other seal viruses detected in China and Korea, and does not exhibit a unique sequence trait distinct from that of human and mosquito strains. We demonstrated that the seal isolate is pathogenic to mice and causes neuronal symptoms. These data suggest that seals should be considered a susceptible dead-end host for circulating JEV in natural settings.
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Affiliation(s)
- Marina Fujii
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan; (M.F.); (H.M.); (A.T.-U.); (S.M.)
| | - Soma Ito
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan; (S.I.); (J.K.C.)
| | | | - James K. Chambers
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan; (S.I.); (J.K.C.)
| | - Hiromichi Matsugo
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan; (M.F.); (H.M.); (A.T.-U.); (S.M.)
| | - Akiko Takenaka-Uema
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan; (M.F.); (H.M.); (A.T.-U.); (S.M.)
| | - Shin Murakami
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan; (M.F.); (H.M.); (A.T.-U.); (S.M.)
| | - Kazuyuki Uchida
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan; (S.I.); (J.K.C.)
| | - Taisuke Horimoto
- Laboratory of Veterinary Microbiology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan; (M.F.); (H.M.); (A.T.-U.); (S.M.)
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Xia Q, Yang Y, Zhang Y, Zhou L, Ma X, Xiao C, Zhang J, Li Z, Liu K, Li B, Shao D, Qiu Y, Wei J, Ma Z. Shift in dominant genotypes of Japanese encephalitis virus and its impact on current vaccination strategies. Front Microbiol 2023; 14:1302101. [PMID: 38045034 PMCID: PMC10690641 DOI: 10.3389/fmicb.2023.1302101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/01/2023] [Indexed: 12/05/2023] Open
Abstract
Japanese encephalitis (JE) is a zoonotic ailment from the Japanese encephalitis virus (JEV). JEV belongs to the flavivirus genus and is categorized into a solitary serotype consisting of five genetically diverse genotypes (I, II, III, IV, and V). The JEV genotype III (GIII) was the prevailing strain responsible for multiple outbreaks in countries endemic to JEV until 1990. In recent years, significant improvements have occurred in the epidemiology of JE, encompassing the geographical expansion of the epidemic zone and the displacement of prevailing genotypes. The dominant genotype of the JEV has undergone a progressive shift from GIII to GI due to variations in its adaptability within avian populations. From 2021 to 2022, Australia encountered an epidemic of viral encephalitis resulting from infection with the GIV JEV pathogen. The current human viral encephalitis caused by GIV JEV is the initial outbreak since its initial discovery in Indonesia during the late 1970s. Furthermore, following a time frame of 50 years, the detection and isolation of GV JEV have been reported in Culex mosquitoes across China and South Korea. Evidence suggests that the prevalence of GIV and GV JEV epidemic regions may be on the rise, posing a significant threat to public safety and the sustainable growth of animal husbandry. The global approach to preventing and managing JE predominantly revolves around utilizing the GIII strain vaccine for vaccination purposes. Nevertheless, research has demonstrated that the antibodies generated by the GIII strain vaccine exhibit limited capacity to neutralize the GI and GV strains. Consequently, these antibodies cannot protect against JEV challenge caused by animal GI and GV strains. The limited cross-protective and neutralizing effects observed between various genotypes may be attributed to the low homology of the E protein with other genotypes. In addition, due to the GIV JEV outbreak in Australia, further experiments are needed to evaluate the protective efficiency of the current GIII based JE vaccine against GIV JEV. The alteration of the prevailing genotype of JEV and the subsequent enlargement of the geographical extent of the epidemic have presented novel obstacles in JE prevention and control. This paper examines the emerging features of the JE epidemic in recent years and the associated problems concerning prevention and control.
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Affiliation(s)
- Qiqi Xia
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yang Yang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yan Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Lujia Zhou
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Xiaochun Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Changguang Xiao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Junjie Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Zongjie Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Ke Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Beibei Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Donghua Shao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yafeng Qiu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Jianchao Wei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Zhiyong Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
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Kim HH, Yang DK, Ji M, Lee SK, Hyun BH. Genotype-specific neutralizing antibody titers against Japanese encephalitis virus genotypes 1 and 3 in horses immunized with a genotype 3 vaccine. Clin Exp Vaccine Res 2020; 9:102-107. [PMID: 32864366 PMCID: PMC7445317 DOI: 10.7774/cevr.2020.9.2.102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/25/2020] [Accepted: 07/28/2020] [Indexed: 11/15/2022] Open
Abstract
Purpose Japanese encephalitis is one of the most important mosquito-borne and zoonotic diseases in Asia and the Pacific region. Although the dominant Japanese encephalitis virus (JEV) genotype has shifted from G3 to G1 in Korea since 1990, a G3 strain (Anyang 300) has been used in vaccines for horses for almost 40 years. This study aimed to investigate the seroconversion rates and geometric mean titers (GMTs) of virus-neutralizing antibodies (VNAs) against JEV G1 and G3 in horses immunized with the G3 vaccine. Materials and Methods Serum samples of 1,231 horses immunized with the Anyang 300 vaccine were collected in 2018. VNA titers against JEV KV1899 (G1) and Anyang 300 (G3) were measured in all serum samples using the virus neutralization test. Titers were analyzed according to blood sampling time (prior to and following annual revaccination), age, and region. Results Rates of VNA titer >10 were 45.1% and 77.8% for G1, and 49.1% and 82.9% for G3 in samples taken before and after revaccination, respectively. GMTs of genotype-specific VNAs against JEV G1 and G3 were 8.3 and 11.6 before revaccination and rose to 27.2 and 65.4 following revaccination. Overall sero-positivity did not significantly differ between genotypes, but GMTs significantly differed among genotypes and sampling times. No significant difference was found in GMTs among age groups or regions. Conclusion Genotype-specific neutralizing antibody titers against JEV G1 and G3 differed significantly in horses immunized with the G3 vaccine. Antigenic differences between genotypes could reduce the vaccine's efficacy, requiring the development of a new vaccine.
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Affiliation(s)
- Ha-Hyun Kim
- Viral Disease Research Division, Animal and Plant Quarantine Agency, Gimcheon, Korea
| | - Dong-Kun Yang
- Viral Disease Research Division, Animal and Plant Quarantine Agency, Gimcheon, Korea
| | - Miryeon Ji
- Viral Disease Research Division, Animal and Plant Quarantine Agency, Gimcheon, Korea
| | | | - Bang-Hun Hyun
- Viral Disease Research Division, Animal and Plant Quarantine Agency, Gimcheon, Korea
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Kading RC, Abworo EO, Hamer GL. Rift Valley Fever Virus, Japanese Encephalitis Virus, and African Swine Fever Virus: Three Transboundary, Vector-Borne, Veterinary Biothreats With Diverse Surveillance, and Response Capacity Needs. Front Vet Sci 2019; 6:458. [PMID: 31921916 PMCID: PMC6923192 DOI: 10.3389/fvets.2019.00458] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 11/28/2019] [Indexed: 12/20/2022] Open
Abstract
Early detection of emerging foreign animal diseases is critical to pathogen surveillance and control programs. Rift valley fever virus (RVFV), Japanese encephalitis virus (JEV), and African swine fever virus (ASFV) represent three taxonomically and ecologically diverse vector-borne viruses with the potential to be introduced to the United States. To promote preparedness for such an event, we reviewed the current surveillance strategies and diagnostic tools in practice around the world for these emerging viruses, and summarized key points pertaining to the availability of existing guidelines and strategic approaches for early detection, surveillance, and disease management activities. We compare and contrast the surveillance and management approaches of these three diverse agents of disease as case studies to emphasize the importance of the ecological context and biology of vectors and vertebrate hosts. The information presented in this review will inform stakeholders of the current state of surveillance approaches against these transboundary foreign animal disease which threaten the United States.
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Affiliation(s)
- Rebekah C Kading
- Arthropod-Borne Infectious Disease Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States
| | | | - Gabriel L Hamer
- Department of Entomology, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX, United States
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5
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Early Events in Japanese Encephalitis Virus Infection: Viral Entry. Pathogens 2018; 7:pathogens7030068. [PMID: 30104482 PMCID: PMC6161159 DOI: 10.3390/pathogens7030068] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/31/2018] [Accepted: 08/06/2018] [Indexed: 12/15/2022] Open
Abstract
Japanese encephalitis virus (JEV), a mosquito-borne zoonotic flavivirus, is an enveloped positive-strand RNA virus that can cause a spectrum of clinical manifestations, ranging from mild febrile illness to severe neuroinvasive disease. Today, several killed and live vaccines are available in different parts of the globe for use in humans to prevent JEV-induced diseases, yet no antivirals are available to treat JEV-associated diseases. Despite the progress made in vaccine research and development, JEV is still a major public health problem in southern, eastern, and southeastern Asia, as well as northern Oceania, with the potential to become an emerging global pathogen. In viral replication, the entry of JEV into the cell is the first step in a cascade of complex interactions between the virus and target cells that is required for the initiation, dissemination, and maintenance of infection. Because this step determines cell/tissue tropism and pathogenesis, it is a promising target for antiviral therapy. JEV entry is mediated by the viral glycoprotein E, which binds virions to the cell surface (attachment), delivers them to endosomes (endocytosis), and catalyzes the fusion between the viral and endosomal membranes (membrane fusion), followed by the release of the viral genome into the cytoplasm (uncoating). In this multistep process, a collection of host factors are involved. In this review, we summarize the current knowledge on the viral and cellular components involved in JEV entry into host cells, with an emphasis on the initial virus-host cell interactions on the cell surface.
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Mansfield KL, Hernández-Triana LM, Banyard AC, Fooks AR, Johnson N. Japanese encephalitis virus infection, diagnosis and control in domestic animals. Vet Microbiol 2017; 201:85-92. [PMID: 28284628 DOI: 10.1016/j.vetmic.2017.01.014] [Citation(s) in RCA: 116] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 01/12/2017] [Accepted: 01/13/2017] [Indexed: 11/16/2022]
Abstract
Japanese encephalitis virus (JEV) is a significant cause of neurological disease in humans throughout Asia causing an estimated 70,000 human cases each year with approximately 10,000 fatalities. The virus contains a positive sense RNA genome within a host-derived membrane and is classified within the family Flaviviridae. Like many flaviviruses, it is transmitted by mosquitoes, particularly those of the genus Culex in a natural cycle involving birds and some livestock species. Spill-over into domestic animals results in a spectrum of disease ranging from asymptomatic infection in some species to acute neurological signs in others. The impact of JEV infection is particularly apparent in pigs. Although infection in adult swine does not result in symptomatic disease, it is considered a significant reproductive problem causing abortion, still-birth and birth defects. Infected piglets can display fatal neurological disease. Equines are also infected, resulting in non-specific signs including pyrexia, but occasionally leading to overt neurological disease that in extreme cases can lead to death. Veterinary vaccination is available for both pigs and horses. This review of JEV disease in livestock considers the current diagnostic techniques available for detection of the virus. Options for disease control and prevention within the veterinary sector are discussed. Such measures are critical in breaking the link to zoonotic transmission into the human population where humans are dead-end hosts.
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Affiliation(s)
- Karen L Mansfield
- Wildlife Zoonoses and Vector-Borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom; Department of Clinical Infection, Microbiology and Immunology, Institute for Infection and Global Health, University of Liverpool, Liverpool, L69 7BE, United Kingdom
| | - Luis M Hernández-Triana
- Wildlife Zoonoses and Vector-Borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom
| | - Ashley C Banyard
- Wildlife Zoonoses and Vector-Borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom
| | - Anthony R Fooks
- Wildlife Zoonoses and Vector-Borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom; Department of Clinical Infection, Microbiology and Immunology, Institute for Infection and Global Health, University of Liverpool, Liverpool, L69 7BE, United Kingdom
| | - Nicholas Johnson
- Wildlife Zoonoses and Vector-Borne Diseases Research Group, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey, KT15 3NB, United Kingdom; Faculty of Health and Medicine, University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
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7
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Kobayashi D, Isawa H, Ejiri H, Sasaki T, Sunahara T, Futami K, Tsuda Y, Katayama Y, Mizutani T, Minakawa N, Ohta N, Sawabe K. Complete Genome Sequencing and Phylogenetic Analysis of a Getah Virus Strain (Genus Alphavirus, Family Togaviridae) Isolated from Culex tritaeniorhynchus Mosquitoes in Nagasaki, Japan in 2012. Vector Borne Zoonotic Dis 2016; 16:769-776. [PMID: 27827562 DOI: 10.1089/vbz.2016.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Getah virus (GETV; genus Alphavirus, family Togaviridae) is a mosquito-borne virus known to cause disease in horses and pigs. In 2014, for the first time in ∼30 years, a sudden GETV outbreak occurred among racehorses in Ibaraki, Japan. Two years before this outbreak, we obtained multiple GETV isolates from Culex tritaeniorhynchus mosquitoes collected in Nagasaki, Japan and determined the whole genome sequence of GETV isolate 12IH26. Our phylogenetic analysis of GETV strains revealed that the isolate 12IH26 forms a robust clade with the epidemic strains 14-I-605-C1 and 14-I-605-C2 isolated from horses in the 2014 outbreak in Ibaraki. Furthermore, the complete genomic sequence of the isolate 12IH26 was 99.9% identical to those of the 2014 epidemic strains in Ibaraki. Phylogenetic analysis also showed that the recent Japanese GETV strains, including the isolate 12IH26, are closely related to the Chinese and South Korean strains rather than the previous Japanese strains, suggesting that GETV strains may be transported from overseas into Japan through long-distance migration of the infected mosquitoes or migratory birds.
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Affiliation(s)
- Daisuke Kobayashi
- 1 Department of Environmental Parasitology, Tokyo Medical and Dental University , Tokyo, Japan .,2 Department of Medical Entomology, National Institute of Infectious Diseases , Tokyo, Japan
| | - Haruhiko Isawa
- 2 Department of Medical Entomology, National Institute of Infectious Diseases , Tokyo, Japan
| | - Hiroko Ejiri
- 2 Department of Medical Entomology, National Institute of Infectious Diseases , Tokyo, Japan .,3 Division of infectious Diseases Epidemiology and Control, National Defense Medical Research Institute , National Defense Medical College, Saitama, Japan
| | - Toshinori Sasaki
- 2 Department of Medical Entomology, National Institute of Infectious Diseases , Tokyo, Japan
| | - Toshihiko Sunahara
- 4 Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University , Nagasaki, Japan
| | - Kyoko Futami
- 4 Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University , Nagasaki, Japan
| | - Yoshio Tsuda
- 2 Department of Medical Entomology, National Institute of Infectious Diseases , Tokyo, Japan
| | - Yukie Katayama
- 5 Research and Education Center for Prevention of Global Infectious Diseases of Animals, Tokyo University of Agriculture and Technology , Tokyo, Japan
| | - Tetsuya Mizutani
- 5 Research and Education Center for Prevention of Global Infectious Diseases of Animals, Tokyo University of Agriculture and Technology , Tokyo, Japan
| | - Noboru Minakawa
- 4 Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki University , Nagasaki, Japan
| | - Nobuo Ohta
- 1 Department of Environmental Parasitology, Tokyo Medical and Dental University , Tokyo, Japan
| | - Kyoko Sawabe
- 2 Department of Medical Entomology, National Institute of Infectious Diseases , Tokyo, Japan
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Jeoung HY, Yang SJ, Choi YK, Lee JH, Seo HJ, Kim SH, Cho YS, Kim YJ, Cho IS, Park JY. Surveillance of Encephalitis-Causing Arboviruses in Horses in South Korea. J Equine Vet Sci 2016. [DOI: 10.1016/j.jevs.2015.11.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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9
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Epizootiological Investigation of Getah Virus Infection among Racehorses in Japan in 2014. J Clin Microbiol 2015; 53:2286-91. [PMID: 25972425 DOI: 10.1128/jcm.00550-15] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 05/07/2015] [Indexed: 11/20/2022] Open
Abstract
To clarify the factors causing an outbreak in 2014 of Getah virus infection among racehorses at the Miho training center, Japan, we isolated virus strains and performed an epizootiological investigation of affected horses and related horse populations. Three Getah virus isolates were recovered from clinical samples, and one of them (14-I-605) was used in a virus-neutralizing test. Of the affected horses (n = 33), 20 (60.6%) were 2-year-olds. We investigated the histories of Getah virus vaccination of the affected horses and the whole population at the Miho training center. Among the 2-year-old population, the prevalence of the disease in horses that had been vaccinated once was 14.1%. This was significantly higher than that in horses that had been vaccinated twice or more (1.3%; P < 0.01). Among horses that had entered the training center from farms in Ibaraki Prefecture surrounding the training center and from neighboring Chiba Prefecture, the rate of seropositivity for Getah virus was 13.0% in September 2014 and 42.9% in October 2014; that in the corresponding periods in 2010 and 2013 was 0%. In conclusion, we identified two possible causes of the outbreak of Getah virus infection in the training center in 2014: (i) the existence of susceptible horses that had received only one dose of vaccination before the outbreak and (ii) increased risk of exposure to the virus because of epizootic Getah virus infection among horses on surrounding farms in Ibaraki and Chiba prefectures.
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10
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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: 71] [Impact Index Per Article: 7.9] [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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11
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Yang DK, Oh YI, Kim HR, Lee YJ, Moon OK, Yoon H, Kim B, Lee KW, Song JY. Serosurveillance for Japanese encephalitis virus in wild birds captured in Korea. J Vet Sci 2012; 12:373-7. [PMID: 22122903 PMCID: PMC3232397 DOI: 10.4142/jvs.2011.12.4.373] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Climate change induced by recent global warming may have a significant impact on vector-borne and zoonotic diseases. For example, the distribution of Japanese encephalitis virus (JEV) has expanded into new regions. We surveyed the levels of hemagglutination-inhibition (HI) antibodies against JEV (Family Flaviviridae, genus Flavivirus) in wild birds captured in Korea. Blood samples were collected from 1,316 wild birds including the following migratory birds: Oceanodroma castro (n = 4), Anas formosa (n = 7), Anas penelope (n = 20), Fulica atra (n = 30), Anas acuta (n = 89), Anas crecca (n = 154), Anas platyrhynchos (n = 214), Aix galericulata (n = 310), and Anas poecilorhyncha (n = 488). All were captured in 16 locations in several Korea provinces between April 2007 and December 2009. Out of the 1,316 serum samples tested, 1,141 (86.7%) were positive for JEV. Wild birds captured in 2009 had a higher seroprevalence of ant-JEV antibodies than those captured in 2007. Wild birds with an HI antibody titer of 1 : 1,280 or higher accounted for 21.2% (280/1,316) of the animals tested. These findings indicated that wild birds from the region examined in our study have been exposed to JEV and may pose a high risk for introducing a new JEV genotype into Korea.
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Affiliation(s)
- Dong-Kun Yang
- Animal and Plant and Fisheries Quarantine and Inspection Agency, MIFAFF, Anyang 430-757, Korea.
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12
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Yang DK, Kim HH, Hyun BH, Lim SI, Nam YK, Nah JJ, Song JY. Detection of Neutralizing Antibody Against Japanese Encephalitis Virus in Wild Boars of Korea. ACTA ACUST UNITED AC 2012. [DOI: 10.4167/jbv.2012.42.4.353] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Dong-Kun Yang
- Animal, Plant and Fishery Quarantine Inspection Agency, MIFAFF, Anyang, Korea
| | - Ha-Hyun Kim
- Animal, Plant and Fishery Quarantine Inspection Agency, MIFAFF, Anyang, Korea
| | - Bang-Hun Hyun
- Animal, Plant and Fishery Quarantine Inspection Agency, MIFAFF, Anyang, Korea
| | - Seong-In Lim
- Animal, Plant and Fishery Quarantine Inspection Agency, MIFAFF, Anyang, Korea
| | - Yun-Kyoung Nam
- College of Veterinary Medicine, JeonBuk National University, JeonJu, Korea
| | - Jin-Ju Nah
- Animal, Plant and Fishery Quarantine Inspection Agency, MIFAFF, Anyang, Korea
| | - Jae-Young Song
- Animal, Plant and Fishery Quarantine Inspection Agency, MIFAFF, Anyang, Korea
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13
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Shirafuji H, Kanehira K, Kamio T, Kubo M, Shibahara T, Konishi M, Murakami K, Nakamura Y, Yamanaka T, Kondo T, Matsumura T, Muranaka M, Katayama Y. Antibody responses induced by experimental West Nile virus infection with or without previous immunization with inactivated Japanese encephalitis vaccine in horses. J Vet Med Sci 2009; 71:969-74. [PMID: 19652487 DOI: 10.1292/jvms.71.969] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A group of horses immunized with inactivated Japanese encephalitis (JE) vaccine (JE-Immune Group) and a group of non-immunized horses (Non-Immune Group) were infected with West Nile virus (WNV). After WNV infection, neutralizing (Nt) antibody (Ab) titers to WNV were higher than those to JE virus (JEV) in the Non-Immune Group, but the NtAb titers to JEV were higher than those to WNV during most of the post-challenge observation period in the JE-Immune Group. Immunoglobulin M (IgM) Abs to WNV tested positive in the Non-Immune Group but negative in the JE-Immune Group, except for in one horse. These results suggest that diagnosis of WNV infection in JE-immunized horses requires serological tests for NtAb and IgM titers to both WNV and JEV.
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Affiliation(s)
- Hiroaki Shirafuji
- Research Team for Zoonotic Diseases, National Institute of Animal Health, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856, Japan.
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14
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Yang DK, Kim BH, Kweon CH, Nah JJ, Kim HJ, Lee KW, Yang YJ, Mun KW. Serosurveillance for Japanese encephalitis, Akabane, and Aino viruses for Thoroughbred horses in Korea. J Vet Sci 2009; 9:381-5. [PMID: 19043313 PMCID: PMC2811779 DOI: 10.4142/jvs.2008.9.4.381] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recent global warming trends may have a significant impact on vector-borne viral diseases, possibly affecting vector population dynamics and disease transmission. This study measured levels of hemagglutination-inhibition (HI) antibodies against Japanese encephalitis virus (JEV) and neutralizing antibodies against Akabane virus (AKAV) and Aino virus (AINV) for Thoroughbred horses in Korea. Blood samples were collected from 989 racehorses in several provinces, between October 2005 and March 2007. Sera were tested using either an HI assay or a virus neutralization test. Approximately half (49.7%; 492/989) of the horses tested were antibody-positive for JEV. The HI titer against JEV was significantly correlated with racehorse age (p < 0.05). Horses with an HI antibody titer of 1:160 or higher accounted for 3.9% of the animals tested, indicating that vectors transmitting arthropod-borne viruses bit relatively few horses. In contrast, 3.8% (19/497) and 19.5% (97/497) of horse sera collected in March 2007 were positive against AKAV and AINV, respectively. The presence of antibodies against AKAV and AINV may indicate the multiplication of AKAV and AINV in these horses.
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Affiliation(s)
- Dong Kun Yang
- National Veterinary Research and Quarantine Service, Anyang 430-824, Korea.
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Satou K, Nishiura H. Evidence of the Partial Effects of Inactivated Japanese Encephalitis Vaccination: Analysis of Previous Outbreaks in Japan From 1953 to 1960. Ann Epidemiol 2007; 17:271-7. [PMID: 17300956 DOI: 10.1016/j.annepidem.2006.10.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2006] [Revised: 09/07/2006] [Accepted: 10/16/2006] [Indexed: 11/17/2022]
Abstract
PURPOSE To evaluate the partial effects of vaccination against equine Japanese encephalitis (JE) and characterize other prognostic factors based on previous outbreak records in Japan from 1953 to 1960. METHODS Individual case records, which included demographic information, vaccination history, and clinical information (dates of onset, recovery and death, and symptoms), were investigated. The relations between two outcomes, JE death and symptomatic period, and other variables were examined. RESULTS Of a total reported 803 cases during the observation period, 453 (56.5%) were diagnosed with either serological, histopathological, or epizootiological methods. Vaccination (adjusted odds ratio=0.77, 95% confidence interval: 0.61, 0.97) and an older age (adjusted odds ratio=0.83, 95% confidence interval: 0.71, 0.96) significantly reduced the risk of JE death. The symptomatic period was also significantly shortened with vaccination (p<0.001). CONCLUSIONS The risk of JE death was lowered and the symptomatic period of survivors shortened with inactivated JE vaccination. These findings demonstrate the partial effects of vaccination in reducing the burden of this disease.
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Affiliation(s)
- Kunio Satou
- Department of Epidemiology, National Institute of Animal Health, Tsukuba, Japan.
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Yamanaka T, Tsujimura K, Kondo T, Yasuda W, Okada A, Noda K, Okumura T, Matsumura T. Isolation and genetic analysis of Japanese encephalitis virus from a diseased horse in Japan. J Vet Med Sci 2006; 68:293-5. [PMID: 16598178 DOI: 10.1292/jvms.68.293] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Japanese encephalitis (JE) developed in an unvaccinated half-bred horse kept in Tottori Prefecture, Japan. The animal showed ataxia with pyrexia and low appetite, and ultimately died. A viral strain was isolated from the cerebrum of the horse and was identified as JE virus (JEV) by RT-PCR using JEV specific primers. The isolated JEV was classified into genotype I by nucleotide sequence analysis of the viral envelope gene. We believe that this is the first report of the genotype I strain being isolated from a horse.
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Affiliation(s)
- Takashi Yamanaka
- Epizootic Research Center, Equine Research Institute, Japan Racing Association, Tochigi 329-0412, Japan
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Abstract
Getah virus is a member of the genus Alphavirus in the family Togaviridae and has been frequently isolated from mosquitoes. Seroepizootiologic studies indicate that the virus is mosquito-borne and widespread, ranging from Eurasia to southeast and far eastern Asia, the Pacific islands, and Australasia. The natural host animal of the virus was not known until the first recognized occurrence of Getah virus infection among racehorses in two training centers in Japan in 1978. Outbreaks of clinical disease due to Getah virus infection occur infrequently, and only one outbreak has been reported outside Japan; this was in India in 1990. Clinical signs of the disease are mild and nonlife-threatening and are characterized by pyrexia, edema of the hind limbs, swelling of the submandibular lymph nodes, and urticarial rash, as reported in the 1978 epizootic. The morbidity was 37.9% (722 of 1903 horses) in one training center, with 96% of 722 affected horses making a full clinical recovery within a week without any significant sequelae. Antibodies against Getah virus were detected in 61.2% (172 of 281) and 55.8% (254 of 455) of horses at two training centers, respectively. Virus isolation can be attempted in VERO, RK-13, BHK-21, and many other cell lines as well as in suckling mouse brain. Blood plasma collected from suspect cases of infection at the onset of pyrexia is the specimen of choice. A diagnosis of Getah virus infection can also be confirmed serologically based on testing acute and convalescent phase sera by using SN, CF, HI, and ELISA tests. An inactivated vaccine is available for the prevention and control of Getah virus infection in horses in Japan.
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Affiliation(s)
- Y Fukunaga
- Epizootic Research Station, Equine Research Institute, Japan Racing Association, Tochigi, Japan
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