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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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Yadav M, Dahiya N, Sehrawat N. Mosquito gene targeted RNAi studies for vector control. Funct Integr Genomics 2023; 23:180. [PMID: 37227504 DOI: 10.1007/s10142-023-01072-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/26/2023]
Abstract
Vector-borne diseases are serious public health concern. Mosquito is one of the major vectors responsible for the transmission of a number of diseases like malaria, Zika, chikungunya, dengue, West Nile fever, Japanese encephalitis, St. Louis encephalitis, and yellow fever. Various strategies have been used for mosquito control, but the breeding potential of mosquitoes is such tremendous that most of the strategies failed to control the mosquito population. In 2020, outbreaks of dengue, yellow fever, and Japanese encephalitis have occurred worldwide. Continuous insecticide use resulted in strong resistance and disturbed the ecosystem. RNA interference is one of the strategies opted for mosquito control. There are a number of mosquito genes whose inhibition affected mosquito survival and reproduction. Such kind of genes could be used as bioinsecticides for vector control without disturbing the natural ecosystem. Several studies have targeted mosquito genes at different developmental stages by the RNAi mechanism and result in vector control. In the present review, we included RNAi studies conducted for vector control by targeting mosquito genes at different developmental stages using different delivery methods. The review could help the researcher to find out novel genes of mosquitoes for vector control.
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Affiliation(s)
- Mahima Yadav
- Department of Genetics, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Nisha Dahiya
- Department of Genetics, Maharshi Dayanand University, Rohtak, Haryana, India
| | - Neelam Sehrawat
- Department of Genetics, Maharshi Dayanand University, Rohtak, Haryana, India.
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Relevant Day/Night Temperatures Simulating Belgian Summer Conditions Reduce Japanese Encephalitis Virus Dissemination and Transmission in Belgian Field-Collected Culex pipiens Mosquitoes. Viruses 2023; 15:v15030764. [PMID: 36992473 PMCID: PMC10053291 DOI: 10.3390/v15030764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/10/2023] [Accepted: 03/13/2023] [Indexed: 03/19/2023] Open
Abstract
Japanese encephalitis virus (JEV), a zoonotic mosquito-borne Flavivirus, can be considered an emerging infectious disease. Therefore, vector competence studies with indigenous mosquitoes from regions where JEV is not yet endemic are of great importance. In our study, we compared the vector competence of Culex pipiens mosquitoes emerged from Belgian field-caught larvae under two different temperature conditions: a constant 25 °C and a 25/15 °C day/night temperature gradient representing typical summer temperatures in Belgium. Three- to seven-day-old F0-generation mosquitoes were fed on a JEV genotype 3 Nakayama strain spiked blood-meal and incubated for 14 days at the two aforementioned temperature conditions. Similar infection rates of 36.8% and 35.2% were found in both conditions. The observed dissemination rate in the gradient condition was, however, significantly lower compared to the constant temperature condition (8% versus 53.6%, respectively). JEV was detected by RT-qPCR in the saliva of 13.3% of dissemination positive mosquitoes in the 25 °C condition, and this transmission was confirmed by virus isolation in 1 out of 2 RT-qPCR positive samples. No JEV transmission to saliva was detected in the gradient condition. These results suggest that JEV transmission by Culex pipiens mosquitoes upon an accidental introduction in our region is unlikely under current climatic conditions. This could change in the future when temperatures increase due to climate change.
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Wong ML, Zulzahrin Z, Vythilingam I, Lau YL, Sam IC, Fong MY, Lee WC. Perspectives of vector management in the control and elimination of vector-borne zoonoses. Front Microbiol 2023; 14:1135977. [PMID: 37025644 PMCID: PMC10070879 DOI: 10.3389/fmicb.2023.1135977] [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: 01/02/2023] [Accepted: 02/28/2023] [Indexed: 04/08/2023] Open
Abstract
The complex transmission profiles of vector-borne zoonoses (VZB) and vector-borne infections with animal reservoirs (VBIAR) complicate efforts to break the transmission circuit of these infections. To control and eliminate VZB and VBIAR, insecticide application may not be conducted easily in all circumstances, particularly for infections with sylvatic transmission cycle. As a result, alternative approaches have been considered in the vector management against these infections. In this review, we highlighted differences among the environmental, chemical, and biological control approaches in vector management, from the perspectives of VZB and VBIAR. Concerns and knowledge gaps pertaining to the available control approaches were discussed to better understand the prospects of integrating these vector control approaches to synergistically break the transmission of VZB and VBIAR in humans, in line with the integrated vector management (IVM) developed by the World Health Organization (WHO) since 2004.
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Affiliation(s)
- Meng Li Wong
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Zulhisham Zulzahrin
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Indra Vythilingam
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Yee Ling Lau
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - I-Ching Sam
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- Department of Medical Microbiology, University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia
| | - Mun Yik Fong
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Wenn-Chyau Lee
- Department of Parasitology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
- A*STAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- *Correspondence: Wenn-Chyau Lee,
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Isolation and Genetic Characterization of Japanese Encephalitis Virus Two Decades after Its Elimination in Singapore. Viruses 2022; 14:v14122662. [PMID: 36560666 PMCID: PMC9786948 DOI: 10.3390/v14122662] [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: 10/18/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 11/30/2022] Open
Abstract
Japanese encephalitis virus (JEV) is an important arbovirus in Asia that can cause serious neurological disease. JEV is transmitted by mosquitoes in an enzootic cycle involving porcine and avian reservoirs, in which humans are accidental, dead-end hosts. JEV is currently not endemic in Singapore, after pig farming was abolished in 1992; the last known human case was reported in 2005. However, due to its location along the East-Asian Australasian Flyway (EAAF), Singapore is vulnerable to JEV re-introduction from the endemic regions. Serological and genetic evidence in the last decade suggests JEV's presence in the local fauna. In the present study, we report the genetic characterization and the first isolation of JEV from 3214 mosquito pools consisting of 41,843 Culex mosquitoes, which were trapped from April 2014 to May 2021. The findings demonstrated the presence of genotype I of JEV (n = 10), in contrast to the previous reports of the presence of genotype II of JEV in Singapore. The genetic analyses also suggested that JEV has entered Singapore on several occasions and has potentially established an enzootic cycle in the local fauna. These observations have important implications in the risk assessment and the control of Japanese encephalitis in non-endemic countries, such as Singapore, that are at risk for JEV transmission.
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Sahu RC, Suthar T, Pathak A, Jain K. Interventions for the Prevention and Treatment of Japanese Encephalitis. Curr Infect Dis Rep 2022; 24:189-204. [PMID: 36187900 PMCID: PMC9510552 DOI: 10.1007/s11908-022-00786-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2022] [Indexed: 11/04/2022]
Abstract
Purpose of Review Japanese encephalitis (JE), a clinical indication of JE virus–induced brain inflammation, is the most prevalent cause of viral encephalitis in the world. This review gives a comprehensive update on the epidemiology, clinical features, therapeutic trials and approaches for preventing the spread of JE. It also outlines the different JE vaccines used in various countries and recommendations for administration of JE vaccines. Recent Findings According to the WHO, annual incidence of JE is estimated to be approximately 68,000 cases worldwide. It is widespread across Asia–Pacific, with a potential for worldwide transmission. In endemic locations, JE is believed to affect children below 6 years of age, but in newly affected areas, both adults and children are at risk due to a lack of protective antibodies. Various vaccines have been developed for the prevention of JE and are being administered in endemic countries. Summary JE is a neuroinvasive disease that causes symptoms ranging from simple fever to severe encephalitis and death. Despite a vast number of clinical trials on various drugs, there is still no complete cure available, and it can only be prevented by adequate vaccination. Various nanotechnological approaches for the prevention and treatment of JE are outlined in this review.
Supplementary Information The online version contains supplementary material available at 10.1007/s11908-022-00786-1.
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Zhao G, Gao Y, Zhang J, Zhang H, Xie C, Nan F, Feng S, Ha Z, Li C, Zhu X, Li Z, Zhang P, Zhang Y, Lu H, Jin N. Toll-like receptor 2 signaling pathway activation contributes to a highly efficient inflammatory response in Japanese encephalitis virus-infected mouse microglial cells by proteomics. Front Microbiol 2022; 13:989183. [PMID: 36171749 PMCID: PMC9511957 DOI: 10.3389/fmicb.2022.989183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 08/12/2022] [Indexed: 12/02/2022] Open
Abstract
Thousands of people die each year from Japanese encephalitis (JE) caused by the Japanese encephalitis virus (JEV), probably due to exacerbation of the inflammatory response that impairs the course of the disease. Microglia are mononuclear phagocytic cells located within the parenchyma of the central nervous system; these play a key role in the innate immune response against JEV infections. However, the involvement of toll-like receptor 2 (TLR2) in the inflammatory response during the early stages of JEV infection in BV2 cells remains. Here, we evaluated protein profiles and determined the role of TLR2 in the inflammatory response of JEV-infected BV2 cells. High-depth tandem mass tags labeling for quantitative proteomics was used to assess JEV infected-BV2 cells and compare immune response profiles at 6, 12, and 24 h post-infection (hpi). In total, 212 upregulated proteins were detected at 6 hpi, 754 at 12 h, and 191 at 24 h. According to GO and KEGG enrichment analysis, the upregulated proteins showed enrichment for proteins related to the immune response. Parallel reaction monitoring tests, western blotting, and qPCR results showed that the adaptor protein MyD88 was not activated. The expression levels of key proteins downstream of MyD88, such as IRAK1, IRAK4, and TRAF6 did not increase; however, the expression levels of PI3K-AKT did increase. By inhibiting key proteins (TLR2, PI3K, and AKT) we confirmed that JEV activated TLR2, thus resulting in a robust inflammatory response. Consequently, the TLR2-PI3K-AKT signaling axis was proven to play a critical in the early stages of the JEV infection-induced inflammatory response in microglia.
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Affiliation(s)
- Guanyu Zhao
- College of Veterinary Medicine, College of Animal Science, Jilin University, Changchun, China
| | - Yan Gao
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Jiaqi Zhang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - He Zhang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
- Research Unit of Key Technologies for Prevention and Control of Virus Zoonoses, Chinese Academy of Medical Sciences, Changchun, China
| | - Changzhan Xie
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Fulong Nan
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Sheng Feng
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Zhuo Ha
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
- Research Unit of Key Technologies for Prevention and Control of Virus Zoonoses, Chinese Academy of Medical Sciences, Changchun, China
| | - Chenghui Li
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Xiangyu Zhu
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Zhuoxin Li
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Ping Zhang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
| | - Ying Zhang
- College of Veterinary Medicine, College of Animal Science, Jilin University, Changchun, China
- *Correspondence: Ying Zhang,
| | - Huijun Lu
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
- Research Unit of Key Technologies for Prevention and Control of Virus Zoonoses, Chinese Academy of Medical Sciences, Changchun, China
- Huijun Lu,
| | - Ningyi Jin
- College of Veterinary Medicine, College of Animal Science, Jilin University, Changchun, China
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun, China
- Research Unit of Key Technologies for Prevention and Control of Virus Zoonoses, Chinese Academy of Medical Sciences, Changchun, China
- Ningyi Jin,
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Suresh KP, Nayak A, Dhanze H, Bhavya AP, Shivamallu C, Achar RR, Silina E, Stupin V, Barman NN, Kumar SK, Syed A, Kollur SP, Shreevatsa B, Patil SS. Prevalence of Japanese encephalitis (JE) virus in mosquitoes and animals of the Asian continent: A systematic review and meta-analysis. J Infect Public Health 2022; 15:942-949. [PMID: 35914358 DOI: 10.1016/j.jiph.2022.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 07/08/2022] [Accepted: 07/21/2022] [Indexed: 10/16/2022] Open
Abstract
BACKGROUND Japanese encephalitis (JE) is a viral zoonotic disease that has been found in several countries of Asia and is responsible for high mortality and morbidity of men and animals in rural and sub-urban endemic areas due to the virus re-circulation among diverse hosts and vectors. The present study estimates the prevalence of the JE virus in the vector and animal population of the Asian continent using a systematic review and meta-analysis. METHODS The Cochran collaborators' Preferred Reporting Items for Systematic Reviews and Meta-Analysis [PRISMA] guidelines were used for systematic review and meta-analysis. The heterogeneity was observed in meta-regression analysis due to several factors including region, species, and different diagnostic assays used in various studies. Thus we did sensitivity and subgroup analysis. RESULTS The prevalence of the JE virus was calculated using a total sample size of 47,391. Subgroup analysis revealed the JE virus prevalence of 39% in the Southeast Asia region, followed by East Asia with 35% and South Asia with 15% prevalence. Hence, the overall pooled prevalence of the JE virus was 26% in the Asian continent. CONCLUSIONS The highest proportion of infection was found in pigs amongst all animals, reinforcing the fact that they can be used as sentinels to predict outbreaks in humans. The findings of this study will enable researchers and policymakers in better understanding the disease's spatial and temporal distribution, as well as in creating and implementing location-specific JE prevention and control measures.
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Affiliation(s)
| | - Akshata Nayak
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru, Karnataka, India
| | - Himani Dhanze
- ICAR-Indian Veterinary Research Institute, Bareilly, UP, India
| | - Anenahalli Panduranga Bhavya
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru, Karnataka, India
| | - Chandan Shivamallu
- Department of Biotechnology and Bioinformatics, School of Life Sciences, JSS Academy of Higher Education and Research, Mysore, Karnataka, India
| | - Raghu Ram Achar
- Division of Biochemistry, School of Life Sciences, JSS Academy of Higher Education and Research, Mysuru, India
| | - Ekaterina Silina
- Department of Surgery, N.I. Pirogov National Research Medical University (RNRMU), Moscow, Russia
| | - Victor Stupin
- Department of Surgery, N.I. Pirogov National Research Medical University (RNRMU), Moscow, Russia
| | - Nagendra Nath Barman
- Department of Microbiology, College of Veterinary Sciences (AAU), Guwahati, Assam, India
| | - Seethakempanahalli Kempanna Kumar
- Department of Ethnoveterinary Sciences and Practices, The University of Trans-Disciplinary Health Science and Technology, Jarakabandekaval, Yelahanka, Bengaluru, India
| | - Asad Syed
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Shiva Prasad Kollur
- Department of Sciences, Amrita School of Arts and Sciences, Amrita Vishwa Vidyapeetham, Mysuru Campus, Mysuru, Karnataka, India
| | - Bhargav Shreevatsa
- Department of Biotechnology and Bioinformatics, School of Life Sciences, JSS Academy of Higher Education and Research, Mysore, Karnataka, India
| | - Sharanagouda S Patil
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru, Karnataka, India.
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Estimates of Japanese Encephalitis mortality and morbidity: A systematic review and modeling analysis. PLoS Negl Trop Dis 2022; 16:e0010361. [PMID: 35613183 PMCID: PMC9173604 DOI: 10.1371/journal.pntd.0010361] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 06/07/2022] [Accepted: 03/25/2022] [Indexed: 11/29/2022] Open
Abstract
Background Japanese Encephalitis (JE) is known for its high case fatality ratio (CFR) and long-term neurological sequelae. Over the years, efforts in JE treatment and control might change the JE fatality risk. However, previous estimates were from 10 years ago, using data from cases in the 10 years before this. Estimating JE disease severity is challenging because data come from countries with different JE surveillance systems, diagnostic methods, and study designs. Without precise and timely JE disease severity estimates, there is continued uncertainty about the JE disease burden and the effect of JE vaccination. Methodology We performed a systematic review to collate age-stratified JE fatality and morbidity data. We used a stepwise model selection with BIC as the selection criteria to identify JE CFR drivers. We used stacked regression, to predict country-specific JE CFR from 1961 to 2030. JE morbidity estimates were grouped from similar study designs to estimate the proportion of JE survivors with long-term neurological sequelae. Principal findings We included 82 and 50 peer-reviewed journal articles published as of March 06 2021 for JE fatality and morbidity with 22 articles in both analyses. Results suggested overall JE CFR estimates of 26% (95% CI 22, 30) in 1961–1979, 20% (95% CI 17, 24) in 1980–1999, 14% (95% CI 11, 17) in 2000–2018, and 14% (95% CI 11, 17) in 2019–2030. Holding other variables constant, we found that JE fatality risk decreased over time (OR: 0.965; 95% CI: 0.947–0.983). Younger JE cases had a slightly higher JE fatality risk (OR: 1.012; 95% CI: 1.003–1.021). The odds of JE fatality in countries with JE vaccination is 0.802 (90% CI: 0.653–0.994; 95% CI: 0.62–1.033) times lower than the odds in countries without JE vaccination. Ten percentage increase in the percentage of rural population to the total population was associated with 15.35% (95% CI: 7.71, 22.57) decrease in JE fatality odds. Ten percentage increase in population growth rate is associated with 3.71% (90% CI: 0.23, 7.18; 95% CI: -0.4, 8.15) increase in JE fatality odds. Adjusting for the effect of year, rural population percent, age of JE cases, and population growth rate, we estimated that there was a higher odds of JE fatality in India compared to China. (OR: 5.46, 95% CI: 3.61–8.31). Using the prediction model we found that, in 2000–2018, Brunei, Pakistan, and Timor-Leste were predicted to have the highest JE CFR of 20%. Bangladesh, Guam, Pakistan, Philippines, and Vietnam had projected JE CFR over 20% for after 2018, whereas the projected JE CFRs were below 10% in China, Indonesia, Cambodia, Myanmar, Malaysia, and Thailand. For disability, we estimated that 36% (min-max 0–85) JE patients recovered fully at hospital discharge. One year after hospital discharge, 46% (min-max 0%-97%) JE survivors were estimated to live normally but 49% (min-max 3% - 86%)till had neurological sequelae. Conclusion JE CFR estimates were lower than 20% after 2000. Our study provides an updated estimation of CFR and proportion of JE cases with long-term neurological sequelae that could help to refine cost-benefit assessment for JE control and elimination programs. Japanese Encephalitis (JE) is known for its high case fatality ratio (CFR) and long-term neurological sequelae. Although JE fatality and morbidity risk might change as the characteristics of the population change with the strengthened surveillance scales, expanded immunization coverage, and healthcare improvements, there have not been any updates in the estimates for JE mortality and morbidity estimates for 10 years. In this paper, we made updated estimates of the JE CFR and the proportion of JE survivors with long-term neurological sequelae by performing a systematic review and developing statistical and machine learning models. We estimated JE CFR decreased over time, with estimates of 26% (95% CI 22, 30) in 1961–1979, 20% (95% CI 17, 24) in 1980–1999, 14% (95% CI 11, 17) in 2000–2018, and 14% (95% CI 11, 17) in 2019–2030. countries without JE vaccination, younger JE cases, higher population growth rate, and lower rural population percentage were associated with higher JE CFR. We estimated that 36% (min-max 0–85) JE patients recovered fully at hospital discharge. One year after hospital discharge, 46% (min-max 0%-97%) JE survivors were estimated to live normally but 49% (min-max 3% - 86%) JE patients still had neurological sequelae. The insights gained will be important in evaluating and updating current JE disease burden among all endemic areas and effectively channeling resources to most needed areas.
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Japanese Encephalitis Virus Interaction with Mosquitoes: A Review of Vector Competence, Vector Capacity and Mosquito Immunity. Pathogens 2022; 11:pathogens11030317. [PMID: 35335641 PMCID: PMC8953304 DOI: 10.3390/pathogens11030317] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 02/28/2022] [Accepted: 03/01/2022] [Indexed: 02/01/2023] Open
Abstract
Japanese encephalitis virus (JEV) is a mosquito-borne zoonotic flavivirus and a major cause of human viral encephalitis in Asia. We provide an overview of the knowledge on vector competence, vector capacity, and immunity of mosquitoes in relation to JEV. JEV has so far been detected in more than 30 mosquito species. This does not necessarily mean that these species contribute to JEV transmission under field conditions. Therefore, vector capacity, which considers vector competence, as well as environmental, behavioral, cellular, and biochemical variables, needs to be taken into account. Currently, 17 species can be considered as confirmed vectors for JEV and 10 other species as potential vectors. Culex tritaeniorhynchus and Culex annulirostris are considered primary JEV vectors in endemic regions. Culex pipiens and Aedes japonicus could be considered as potentially important vectors in the case of JEV introduction in new regions. Vector competence is determined by various factors, including vector immunity. The available knowledge on physical and physiological barriers, molecular pathways, antimicrobial peptides, and microbiome is discussed in detail. This review highlights that much remains to be studied about vector immunity against JEV in order to identify novel strategies to reduce JEV transmission by mosquitoes.
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National Monitoring of Mosquito Populations and Molecular Analysis of Flavivirus in the Republic of Korea in 2020. Microorganisms 2021; 9:microorganisms9102085. [PMID: 34683405 PMCID: PMC8538701 DOI: 10.3390/microorganisms9102085] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 09/29/2021] [Accepted: 09/30/2021] [Indexed: 11/17/2022] Open
Abstract
The Korea Disease Control and Prevention Agency has established centers at 16 locations to screen vector populations and pathogens. The aims of this study were to determine the relative spatiotemporal distributions of mosquitoes that are flavivirus vectors, and to correlate them with instances of flaviviral disease in the Republic of Korea (ROK). We collected 67,203 mosquitoes in traps at 36 collection sites in 30 urban regions and migratory bird habitats in 2020. The trap index was 36.6, and the predominant mosquito species were the Culex pipiens complex, Armigeres subalbatus, Aedes albopictus, Aedes vexans, and Culex tritaeniorhynchus. The mosquitoes were pooled into 4953 pools to monitor flavivirus infection. We determined that the minimum infection rate of flavivirus was 0.01%. Japanese encephalitis virus (JEV) was detected in only seven pools of Culex orientalis from Sangju, and we isolated JVE from two pools. All detected JEV was found to be genotype V by phylogenetic analysis. To the best of our knowledge, this is the first study to isolate genotype V JVE from Culex orientalis in the ROK. Subsequent geographical and ecological studies on mosquitoes will help improve our understanding of the relative risk of flavivirus infection. Future studies should analyze mosquito species distribution and improve flavivirus monitoring and long-term surveillance.
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Sanborn MA, Wuertz KM, Kim HC, Yang Y, Li T, Pollett SD, Jarman RG, Berry IM, Klein TA, Hang J. Metagenomic analysis reveals Culex mosquito virome diversity and Japanese encephalitis genotype V in the Republic of Korea. Mol Ecol 2021; 30:5470-5487. [PMID: 34418188 DOI: 10.1111/mec.16133] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 08/05/2021] [Accepted: 08/13/2021] [Indexed: 12/15/2022]
Abstract
Recent outbreaks of emerging and re-emerging viruses have shown that timely detection of novel arboviruses with epidemic potential is essential to mitigate human health risks. There are rising concerns that emergent JEV genotype V (GV) is circulating in Asia, against which current vaccines may not be efficacious. To ascertain if JEV GV and other arboviruses are circulating in East Asia, we conducted next-generation sequencing on 260 pools of Culex tritaeniorhynchus and Culex bitaeniorhynchus mosquitoes (6540 specimens) collected at Camp Humphreys, Republic of Korea (ROK) in 2018. Interrogation of our data revealed a highly abundant and diverse virosphere that contained sequences from 122 distinct virus species. Our statistical and hierarchical analysis uncovered correlates of potential health, virological, and ecological relevance. Furthermore, we obtained evidence that JEV GV was circulating in Pyeongtaek and, retrospectively, in Seoul in 2016 and placed these findings within the context of human and fowl reservoir activity. Sequence-based analysis of JEV GV showed a divergent genotype that is the most distant from the GIII-derived live attenuated SA14-14-2 vaccine strain and indicated regions probably responsible for reduced antibody affinity. These results emphasize recent concerns of shifting JEV genotype in East Asia and highlight the critical need for a vaccine proven efficacious against this re-emergent virus. Together, our one-health approach to Culex viral metagenomics uncovered novel insights into virus ecology and human health.
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Affiliation(s)
- Mark A Sanborn
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | | | - Heung-Chul Kim
- Force Health Protection & Preventive Medicine, US Army Medical Activity-Korea, 65th Medical Brigade, Unit #15281, APO AP 96271-5281, USA
| | - Yu Yang
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Tao Li
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Simon D Pollett
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Richard G Jarman
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Irina Maljkovic Berry
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Terry A Klein
- Force Health Protection & Preventive Medicine, US Army Medical Activity-Korea, 65th Medical Brigade, Unit #15281, APO AP 96271-5281, USA
| | - Jun Hang
- Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA
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Auerswald H, Maquart PO, Chevalier V, Boyer S. Mosquito Vector Competence for Japanese Encephalitis Virus. Viruses 2021; 13:v13061154. [PMID: 34208737 PMCID: PMC8234777 DOI: 10.3390/v13061154] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/02/2021] [Accepted: 06/02/2021] [Indexed: 12/30/2022] Open
Abstract
Japanese encephalitis virus (JEV) is a zoonotic pathogen mainly found in East and Southeast Asia and transmitted by mosquitoes. The objective of this review is to summarize the knowledge on the diversity of JEV mosquito vector species. Therefore, we systematically analyzed reports of JEV found in field-caught mosquitoes as well as experimental vector competence studies. Based on the investigated publications, we classified 14 species as confirmed vectors for JEV due to their documented experimental vector competence and evidence of JEV found in wild mosquitoes. Additionally, we identified 11 mosquito species, belonging to five genera, with an experimentally confirmed vector competence for JEV but lacking evidence on their JEV transmission capacity from field-caught mosquitoes. Our study highlights the diversity of confirmed and potential JEV vector species. We also emphasize the variety in the study design of vector competence investigations. To account for the diversity of the vector species and regional circumstances, JEV vector competence should be studied in the local context, using local mosquitoes with local virus strains under local climate conditions to achieve reliable data. In addition, harmonization of the design of vector competence experiments would lead to better comparable data, informing vector and disease control measures.
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Affiliation(s)
- Heidi Auerswald
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia
- Correspondence:
| | - Pierre-Olivier Maquart
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia; (P.-O.M.); (S.B.)
| | - Véronique Chevalier
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia;
- UMR ASTRE, CIRAD, INRA, Université de Montpellier, 34000 Montpellier, France
| | - Sebastien Boyer
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia; (P.-O.M.); (S.B.)
- Institut Pasteur, 75015 Paris, France
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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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Fang Y, Zhang W, Xue JB, Zhang Y. Monitoring Mosquito-Borne Arbovirus in Various Insect Regions in China in 2018. Front Cell Infect Microbiol 2021; 11:640993. [PMID: 33791242 PMCID: PMC8006455 DOI: 10.3389/fcimb.2021.640993] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 02/05/2021] [Indexed: 12/03/2022] Open
Abstract
Background Increases in global travel and trade are changing arbovirus distributions worldwide. Arboviruses can be introduced by travelers, migratory birds, or vectors transported via international trade. Arbovirus surveillance in field-collected mosquitoes may provide early evidence for mosquito-borne disease transmission. Methods During the seasons of high mosquito activity of 2018, 29,285 mosquitoes were sampled from seven sentinel sites in various insect regions. The mosquitoes were analyzed by RT-PCR for alphaviruses, flaviviruses, and orthobunyaviruses. Results We detected three strains of Japanese encephalitis virus (JEV), five strains of Getah virus (GETV), and 45 strains of insect-specific flaviviruses including Aedes flavivirus (AeFV, 1), Chaoyang virus (CHAOV, 1), Culex flavivirus (CxFV, 17), Hanko virus (HANKV, 2), QuangBinh virus (QBV, 22), and Yunnan Culex flavivirus (YNCxFV, 2). Whole genomes of one strain each of GETV, CxFV, CHAOV, and AeFV were successfully amplified. Phylogenetic analysis revealed that the new JEV strains detected in the Shanghai and Hubei Provinces belong to the GI-b strain and are phylogenetically close to the NX1889 strain (MT134112) isolated from a patient during a JE outbreak in Ningxia in 2018. GETVs were found in Inner Mongolia, Hubei, and Hainan and belonged to Group III. They were closely related to strains isolated from swine. HANKV was recorded for the first time in China and other ISFVs were newly detected at several sentinel sites. The bias-corrected maximum likelihood estimation value for JEV in Jinshan, Shanghai was 4.52/1,000 (range 0.80-14.64). Hence, there is a potential risk of a JEV epidemic in that region. Conclusion GI-b is the dominant circulating JEV genotype in nature and poses a health risk to animals and humans. The potential threat of widespread GETV distribution as a zoonosis is gradually increasing. The present study also disclosed the dispersion and host range of ISFVs. These findings highlight the importance of tracing the movements of the vectors and hosts of mosquito-borne pathogens in order to prevent and control arbovirus outbreaks in China.
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Affiliation(s)
- Yuan Fang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Chinese Center for Tropical Diseases Research, Ministry of Science and Technology, Shanghai, China
- Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
| | - Wei Zhang
- Zichuan District Center for Disease Control and Prevention, Zibo, China
| | - Jing-Bo Xue
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Chinese Center for Tropical Diseases Research, Ministry of Science and Technology, Shanghai, China
- Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
| | - Yi Zhang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Chinese Center for Tropical Diseases Research, Ministry of Science and Technology, Shanghai, China
- Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
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Lord JS. Changes in Rice and Livestock Production and the Potential Emergence of Japanese Encephalitis in Africa. Pathogens 2021; 10:pathogens10030294. [PMID: 33806470 PMCID: PMC8000791 DOI: 10.3390/pathogens10030294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/15/2021] [Accepted: 03/02/2021] [Indexed: 11/16/2022] Open
Abstract
The known distribution of Japanese encephalitis (JE) is limited to Asia and Australasia. However, autochthonous transmission of Japanese encephalitis virus was reported in Africa for the first time in 2016. Reasons for the current geographic restriction of JE and the circumstances that may permit emergence in non-endemic areas are not well known. Here, I assess potential changes in vector breeding habitat and livestock production in Africa that are conducive to JEV transmission, using open-source data available from the Food and Agriculture Organization between 1961 and 2019. For 16 of 57 countries in Africa, there was evidence of existing, or an increase in, conditions potentially suitable for JE emergence. This comprised the area used for rice production and the predicted proportion of blood meals on pigs. Angola, where autochthonous transmission was reported, was one of these 16 countries. Studies to better quantify the role of alternative hosts, including domestic birds in transmission in endemic regions, would help to determine the potential for emergence elsewhere. In Africa, surveillance programs for arboviruses should not rule out the possibility of Japanese encephalitis virus (JEV) circulation in areas with high pig or bird density coincident with Culicine breeding habitats.
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Affiliation(s)
- Jennifer S Lord
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
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17
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Liu W, Fu S, Ma X, Chen X, Wu D, Zhou L, Yin Q, Li F, He Y, Lei W, Li Y, Xu S, Wang H, Wang Z, Wang H, Yu H, Liang G. An outbreak of Japanese encephalitis caused by genotype Ib Japanese encephalitis virus in China, 2018: A laboratory and field investigation. PLoS Negl Trop Dis 2020; 14:e0008312. [PMID: 32453787 PMCID: PMC7274457 DOI: 10.1371/journal.pntd.0008312] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 06/05/2020] [Accepted: 04/20/2020] [Indexed: 11/23/2022] Open
Abstract
Although Japanese encephalitis virus genotype Ib (JEV GIb) has replaced JEV GIII as the dominant genotype in endemic areas of Asia, no JEV GIb has been isolated from JE cases and natural mosquitoes at the same time in an outbreak of JE. In this study, we conducted virological and molecular biological laboratory tests on JE case samples (serum/cerebrospinal fluid) and locally collected mosquito samples from the 2018 JE outbreak in Ningxia, China. The result of JEV IgM antibody detection showed that 96% (67/70) of the suspected cases were laboratory-confirmed JE cases. Of the mosquitoes collected from local environments, 70% (17400/24900) were Culex tritaeniorhynchus of which 4.6% (16 /348 of the pools tested) were positive for JEV, other mosquitoes were negative. JEVs isolated from both the human cases and C. tritaeniorhynchus specimens belong to JEV GIb and are in the same evolutionary clade according to molecular evolution analyses. JEV GIb was detected simultaneously from specimens of JE cases and mosquito samples collected in nature in this study, suggesting that the JE outbreak that occurred in Ningxia in 2018 was due to infection of JEV GIb. Japanese encephalitis virus (JEV) is recognized as an important encephalitis pathogen all over the world. Its genotype is divided into GI-V. In recent years, JEV GIb (a temperate genotype) has gradually replaced GIII as the prevalent strain in JE endemic areas. Although JEV GIb originated from tropical Asia along with JEV GIa, it has rapidly spread for its advantages in wintering and infecting vectors. Although there have been epidemics caused by JEV GI and GIII, there have been no reports of a JE outbreak caused by JEV GIb alone in northeastern Asia. However, a JE outbreak occurred in the Ningxia Hui Autonomous Region in northern China in summer 2018 which was the first outbreak in Ningxia in recent decades. This paper presents a series of laboratory and field studies of this outbreak. The strain isolated from JE cases as well as JEV detected in Culex tritaeniorhynchus collected from local areas in nature all belonged to JEV GIb and were in the same evolutionary clade. This is the first report of a JE outbreak caused by JEV GIb infection in northeastern Asia (latitude 35 ° 14’– 39 ° 23’ N, longitude 104 ° 17’– 107 ° 39’ E), which used to be a low endemic area of JEV GIII.
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Affiliation(s)
- Wenjing Liu
- Department of Pathogenic Biology, School of Basic Medicine, Qingdao University, Qingdao, People’s Republic of China
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Shihong Fu
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Xuemin Ma
- Ningxia Hui Autonomous Region Center for Disease Control and Prevention, People’s Republic of China
| | - Xiaojing Chen
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Department of Epidemiology, School of Medicine, Jinan University, Guangzhou, People’s Republic of China
| | - Dan Wu
- National Immunization Programme, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Liwei Zhou
- Ningxia Hui Autonomous Region Center for Disease Control and Prevention, People’s Republic of China
| | - Qikai Yin
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Fan Li
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Ying He
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Wenwen Lei
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Yixing Li
- National Immunization Programme, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Songtao Xu
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Huaqing Wang
- National Immunization Programme, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Zhenhai Wang
- Center for Neurology, General Hospital of Ningxia Medical University, Ningxia, People’s Republic of China
| | - Huanyu Wang
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- * E-mail: (HYW); (HY); (GDL)
| | - Hong Yu
- Department of Pathogenic Biology, School of Basic Medicine, Qingdao University, Qingdao, People’s Republic of China
- * E-mail: (HYW); (HY); (GDL)
| | - Guodong Liang
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- * E-mail: (HYW); (HY); (GDL)
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Lien JC, Lin CS, Lai HC, Tsai YC, Lin YF, Huang AC, Huang SH, Lin CW. Antiviral efficacy of bromo-anilino substituents of 4,5-dihydrofuran-3-carboxylate compound CW-33 against Japanese encephalitis virus. Bioorg Med Chem Lett 2019; 29:126742. [PMID: 31648857 DOI: 10.1016/j.bmcl.2019.126742] [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: 08/29/2019] [Revised: 09/26/2019] [Accepted: 10/06/2019] [Indexed: 10/25/2022]
Abstract
Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, occasionally causes severe central nervous system disorders in the risk zone where more than 3 billion people reside. Our prior studies demonstrated antiviral potential of 4,5-dihydrofuran-3-carboxylate compound CW-33 (ethyl 2-(3',5'-dimethylanilino)-4-oxo-4,5-dihydrofuran-3-carboxylate) and its derivative CW-33A ((ethyl 2-(2-fluoroanilino)-4-oxo-4,5-dihydrofuran-3-carboxylate) against JEV infection ((Int. J. Mol. Sci. 2016, 17: E1386; Sci. Rep. 2018, 8: 16595). This study synthesized six new CW-33 derivatives containing chloro, or bromo groups at the C-2, C-3, or C-4 of anilino ring of CW-33, and assessed the antiviral activity and mechanisms of these chloro- and bromo-anilino substitutedderivatives. CW-33K, CW-33L and CW-33M had the bromo-substituents at the C-2, C-3, or C-4 of anilino ring of CW-33, respectively, showing the higher anti-JEV activity than CW-33 and other derivatives. CW-33K (ethyl 2-(2-bromoanilino)-4-oxo-4,5-dihydrofuran-3-carboxylate) exhibited the highest antiviral efficacy and therapeutic index. The IC50 value of CW-33K was less than 5 μM for reducing JEV-induced cytopathic effect, virus infectivity and virus yield. CW-33K significantly inhibited the JEV replication at the early and late stages, suppressing viral RNA synthesis and intracellular JEV particle production. The study demonstrated that the CW-33 derivative with a bromosubstitutionat the C-2 anilino ring improved the antiviral activity JEV, providing the structure-antiviral activity relationship for the development of anti-JEV agents.
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Affiliation(s)
- Jin-Cherng Lien
- School of Pharmacy, China Medical University, Taichung, Taiwan
| | - Chen-Sheng Lin
- Division of Gastroenterology, Kuang Tien General Hospital, Taichung, Taiwan
| | - Hsueh-Chou Lai
- School of Chinese Medicine, China Medical University, Taichung, Taiwan; Division of Hepato-gastroenterology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan
| | - Yu-Chi Tsai
- PhD Program for Health Science and Industry, College of Health Care, China Medical University, Taichung, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, China Medical University, Taichung, Taiwan
| | - Yu-Fong Lin
- Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan
| | - An-Cheng Huang
- Department of Nursing, St. Mary's Junior College of Medicine, Nursing and Management, Yilan County, Taiwan
| | - Su-Hua Huang
- Department of Biotechnology, Asia University, Wufeng, Taichung, Taiwan
| | - Cheng-Wen Lin
- PhD Program for Health Science and Industry, College of Health Care, China Medical University, Taichung, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, China Medical University, Taichung, Taiwan; Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan; Department of Biotechnology, Asia University, Wufeng, Taichung, Taiwan; Chinese Medicine Research Center, China Medical University, Taichung, Taiwan.
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Ladreyt H, Durand B, Dussart P, Chevalier V. How Central Is the Domestic Pig in the Epidemiological Cycle of Japanese Encephalitis Virus? A Review of Scientific Evidence and Implications for Disease Control. Viruses 2019; 11:E949. [PMID: 31618959 PMCID: PMC6832429 DOI: 10.3390/v11100949] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/04/2019] [Accepted: 10/11/2019] [Indexed: 11/17/2022] Open
Abstract
Despite the existence of human vaccines, Japanese encephalitis (JE) remains the leading cause of human encephalitis in Asia. Pigs are described as the main amplifying host, but their role in JE epidemiology needs to be reassessed in order to identify and implement efficient control strategies, for both human and animal health. We aimed to provide a systematic review of publications linked to JE in swine, in terms of both individual and population characteristics of JE virus (JEV) infection and circulation, as well as observed epidemiological patterns. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement to select and analyze relevant articles from the Scopus database, 127 of which were included in the review. Pigs are central, but the implication of secondary hosts cannot be ruled out and should be further investigated. Although human vaccination cannot eradicate the virus, it is clearly the most important means of preventing human disease. However, a better understanding of the actual involvement of domestic pigs as well as other potential JEV hosts in different JEV epidemiological cycles and patterns could help to identify additional/complementary control measures, either by targeting pigs or not, and in some specific epidemiological contexts, contribute to reduce virus circulation and protect humans from JEV infection.
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Affiliation(s)
- Héléna Ladreyt
- Epidemiology Unit, Laboratory for Animal Health, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), University Paris-Est, 94700 Maisons-Alfort, France.
- Agricultural Research for Development (CIRAD), UMR ASTRE, F-34090 Montpellier, France.
| | - Benoit Durand
- Epidemiology Unit, Laboratory for Animal Health, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), University Paris-Est, 94700 Maisons-Alfort, France.
| | - Philippe Dussart
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, PO Box 983, Phnom Penh 12201, Cambodia.
| | - Véronique Chevalier
- Agricultural Research for Development (CIRAD), UMR ASTRE, F-34090 Montpellier, France.
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, PO Box 983, Phnom Penh 12201, Cambodia.
- Agricultural Research for Development (CIRAD), UMR ASTRE, Phnom Penh 12201, Cambodia.
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Yap G, Lim XF, Chan S, How CB, Humaidi M, Yeo G, Mailepessov D, Kong M, Lai YL, Okumura C, Ng LC. Serological evidence of continued Japanese encephalitis virus transmission in Singapore nearly three decades after end of pig farming. Parasit Vectors 2019; 12:244. [PMID: 31101069 PMCID: PMC6525359 DOI: 10.1186/s13071-019-3501-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 05/09/2019] [Indexed: 11/10/2022] Open
Abstract
Background Singapore used to report an annual average of 14 cases of Japanese encephalitis, but ever since the abolishment of pig farms in the early 1990s, the local incidence rate for Japanese encephalitis virus (JEV) infections has reduced drastically. Studies done in the early 2000s demonstrated the presence of JEV-specific antibodies in animals such as wild boars, dogs, chickens and goats on the offshore island and peripheral parts of the Singapore, indicative of prior JEV exposure. A JEV wildlife and sentinel chicken surveillance system was initiated in 2010 through to 2017 to study the animal host seroprofiles. Results A total of 12/371 (3.23%) of resident bird samples, 24/254 (9.45%) of migratory bird samples and 10/66 (15.16%) of wild boar samples were positive for the presence of JEV antibodies. Seroconversions in sentinel chickens were observed at two time points. Through this study, two sites with active transmission of JEV amongst avian or porcine hosts were identified. Conclusions JEV transmission in animal hosts has continued despite the phasing out of pig farming nearly thirty years ago; however, the public health risk of transmission remains low. Environmental management for mosquito population remains key to keeping this risk low.
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Affiliation(s)
- Grace Yap
- Environmental Health Institute, National Environment Agency, Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Xiao Fang Lim
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | | | | | - Mahathir Humaidi
- Environmental Health Institute, National Environment Agency, Singapore, Singapore.
| | - Gladys Yeo
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | - Diyar Mailepessov
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | - Marcella Kong
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | - Yee Ling Lai
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
| | | | - Lee Ching Ng
- Environmental Health Institute, National Environment Agency, Singapore, Singapore
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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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Structure analysis and antiviral activity of CW-33 analogues against Japanese encephalitis virus. Sci Rep 2018; 8:16595. [PMID: 30413749 PMCID: PMC6226475 DOI: 10.1038/s41598-018-34932-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 10/29/2018] [Indexed: 12/11/2022] Open
Abstract
Japanese encephalitis virus (JEV) is a member of neurotropic flaviviruses transmitted by mosquito bites, causing severe central nervous system disorders. Current JEV genotype III vaccines have a low protection against genotype I isolates in the risk zone. The lead compound CW-33, ethyl 2-(3′,5′-dimethylanilino)-4-oxo-4,5-dihydrofuran-3-carboxylate, demonstrates the antiviral activity against JEV with an IC50 values of 38.5 μM for virus yield reduction (Int J Mol Sci 2016,17: E1386). This study synthesized fourteen CW-33 analogues containing a fluoro atom or one methoxy group at the C-2, C-3, or C-4 of anilino ring, and then evaluated for their antiviral activity and mechanism. Among 6 amalogues, CW-33A (ethyl 2-(2-fluoroanilino)-4-oxo- 4,5-dihydrofuran-3-carboxylate), and CW-33D (ethyl 2-(3-methoxyanilino)-4-oxo- 4,5-dihydrofuran-3-carboxylate exhibited antiviral potentials in viral cytopathic effect (CPE) inhibition. CW-33A significantly suppressed the viral protein expression, genome synthesis and intracellular JEV particle production, showing a higher inhibitory effect on JEV yield than CW-33 and CW-33D. The study demonstrated that a mono-fluoro substitution on at the C-2 anilino ring of CW-33 improved the antiviral activity JEV, revealing the structure-activity relationship for developing novel agents against JEV infection.
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Kim HJ, Lyoo HR, Choi JS, Lee YH, Kim BH, Yoo HS. Development of a Quantitative RT-PCR Assay to Differentiate Rift Valley Fever Virus Smithburn Vaccine Strain from Clone 13 Vaccine Strain. Vector Borne Zoonotic Dis 2018; 19:121-127. [PMID: 30300113 DOI: 10.1089/vbz.2018.2342] [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: 11/12/2022] Open
Abstract
A new quantitative RT-PCR assay was developed to differentiate Rift Valley fever (RVF) Smithburn vaccine strain from Clone 13 vaccine strain. The new qRT-PCR assay targeting the S segment (NSs and N gene) was tested on synthesized standard RNA and MP-12 strain viruses. The detection limit of the new qRT-PCR assay is 1 copy/μL of NSs and N, and is able to differentiate the Smithburn vaccine strain of RVF from the Clone 13 vaccine strain. No cross-reactivity with other vector-borne viruses was observed, a factor that is especially important in the Republic of Korea (ROK). To examine the performance of the qRT-PCR, intra- and inter-assay variability data were analyzed and showed high reproducibility. These results indicate that the new qRT-PCR can be used as a safe and cost-effective test. Furthermore, this result suggests the possibility of differentiation between infected and vaccinated animals diagnostic test in RVF-free countries including ROK.
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Affiliation(s)
- Hyun-Joo Kim
- 1 Foreign Animal Disease Division, Animal and Plant Quarantine Agency , Gimcheon-si, Republic of Korea.,2 Department of Infectious Diseases, Colleges of Veterinary Medicine, Seoul National University , Seoul, Republic of Korea
| | - Hye-Rhyoung Lyoo
- 3 Department of Infectious Diseases and Immunology, Virology Division, Faculty of Veterinary Medicine, Utrecht University , Utrecht, the Netherlands
| | - Jeong-Soo Choi
- 1 Foreign Animal Disease Division, Animal and Plant Quarantine Agency , Gimcheon-si, Republic of Korea
| | - Yoon-Hee Lee
- 1 Foreign Animal Disease Division, Animal and Plant Quarantine Agency , Gimcheon-si, Republic of Korea
| | - Byoung-Han Kim
- 1 Foreign Animal Disease Division, Animal and Plant Quarantine Agency , Gimcheon-si, Republic of Korea
| | - Han Sang Yoo
- 2 Department of Infectious Diseases, Colleges of Veterinary Medicine, Seoul National University , Seoul, Republic of Korea
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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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Oliveira AR, Strathe E, Etcheverry L, Cohnstaedt LW, McVey DS, Piaggio J, Cernicchiaro N. Assessment of data on vector and host competence for Japanese encephalitis virus: A systematic review of the literature. Prev Vet Med 2018; 154:71-89. [DOI: 10.1016/j.prevetmed.2018.03.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 03/19/2018] [Accepted: 03/20/2018] [Indexed: 12/15/2022]
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Pearce JC, Learoyd TP, Langendorf BJ, Logan JG. Japanese encephalitis: the vectors, ecology and potential for expansion. J Travel Med 2018; 25:S16-S26. [PMID: 29718435 DOI: 10.1093/jtm/tay009] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 02/20/2018] [Indexed: 01/09/2023]
Abstract
BACKGROUND Japanese encephalitis (JE) is a viral disease predominantly located in South East Asia and commonly associated with transmission between amplifying hosts, such as pigs, and the mosquito Culex tritaeniorhynchus, where human infection represents a dead end in the life cycle of the virus. The expansion of JE beyond an Asiatic confine is dependent on a multitude of complex factors that stem back to genetic subtype variation. A complex interplay of the genetic variation and vector competencies combine with variables such as geography, climate change and urbanization. METHODS Our understanding of JE is still at an early stage with long-term longitudinal vector surveillance necessary to better understand the dynamics of JE transmission and to characterize the role of potential secondary vectors such as Cx. pipiens and Cx. bitaeniorhynchus. The authors review the vectors indicated in transmission and the ecological, genetic and anthropological factors that affect the disease's range and epidemiology. CONCLUSION Monitoring for the presence of JE virus in mosquitoes in general can be used to estimate levels of potential JE exposure, intensity of viral activity and genetic variation of JEV throughout surveyed areas. Increased surveillance and diagnosis of viral encephalitis caused by genotype 5 JE virus is required in particular, with the expansion in epidemiology and disease prevalence in new geographic areas an issue of great concern. Additional studies that measure the impact of vectors (e.g. bionomics and vector competence) in the transmission of JEV and that incorporate environmental factors (e.g. weekly rainfall) are needed to define the roles of Culex species in the viral pathogenesis during outbreak and non-outbreak years.
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Affiliation(s)
- James C Pearce
- ARCTEC, Keppel Street, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Tristan P Learoyd
- Valneva UK Ltd, Centaur House, Ancells Business Park, Ancells Road, Fleet, Hampshire GU51 2UJ, UK
| | - Benjamin J Langendorf
- ARCTEC, Keppel Street, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - James G Logan
- ARCTEC, Keppel Street, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.,Department of Disease Control, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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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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Karthikeyan A, Shanmuganathan S, Pavulraj S, Prabakar G, Pavithra S, Porteen K, Elaiyaraja G, Malik YS. JAPANESE ENCEPHALITIS, RECENT PERSPECTIVES ON VIRUS GENOME, TRANSMISSION, EPIDEMIOLOGY, DIAGNOSIS AND PROPHYLACTIC INTERVENTIONS. ACTA ACUST UNITED AC 2017. [DOI: 10.18006/2017.5(6).730.748] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Chu H, Wu Z, Chen H, Li C, Guo X, Liu R, Wang G, Zhou M, Zhao T. Japanese Encephalitis Virus Infection Rate and Detection of Genotype I From Culex tritaeniorhynchus Collected From Jiangsu, China. Vector Borne Zoonotic Dis 2017; 17:503-509. [PMID: 28509619 DOI: 10.1089/vbz.2016.2086] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Information regarding the infection rate and genotype shifts for Japanese encephalitis virus (JEV) are important for JE vaccine application. In Jiangsu province, China, which is one of the provinces with a high prevalence of JE, JEV infection in swine and mosquitoes in certain cities has only been investigated in 2008-2009. Lianyungang City has one of the highest numbers of JE cases in Jiangsu province, and it has a high risk of JEV invasion via migrant birds. JEV infection in vectors in Lianyungang City, which has urban and rural parts, has not been investigated. In 2015-2016, we collected mosquitoes in cowsheds with ultraviolet light traps and detected JEV by reverse transcription-polymerase chain reaction (RT-PCR) method in Culex tritaeniorhynchus in Xintan village, Xuzhuang village, and Xiaogaozhuang village in Lianyungang City, China. The proportion of positive pools, which is calculated by the number of infected pools to the total number of pools tested in these villages, were 16.67%, 20.00%, and 4.17%, respectively, and the minimum infection rates, which is calculated as the ratio of the number of positive pools to the total number of mosquitoes tested, were 3.33‰, 4.00‰, and 0.83‰, respectively. Four JEV strains from positive samples were coded as LYG-1, LYG-2, LYG-3, and LYG-4, and the complete E genes were sequenced. Furthermore, the complete genome of LYG-3 was sequenced. The phylogenetic analysis indicated that all the four JEV strains belonged to genotype I-b. This is the first report of genotype I JEV strain in Jiangsu province. The high JEV infection rate in Culex tritaeniorhynchus indicated a high risk of JE reemergence in Lianyungang. The detected JEV strains may have similar antigenicity to that of SA14-14-2 according to molecular characters. These findings suggest that the vaccine can still be effective in Lianyungang.
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Affiliation(s)
- Hongliang Chu
- 1 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology , Fengtai District, Beijing, China .,2 Department of Disinfection and Vector Control, Jiangsu Provincial Center for Disease Control and Prevention , Gulou District, Nanjing, China
| | - Zhiming Wu
- 2 Department of Disinfection and Vector Control, Jiangsu Provincial Center for Disease Control and Prevention , Gulou District, Nanjing, China
| | - Hongna Chen
- 2 Department of Disinfection and Vector Control, Jiangsu Provincial Center for Disease Control and Prevention , Gulou District, Nanjing, China
| | - Chunxiao Li
- 1 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology , Fengtai District, Beijing, China
| | - Xiaoxia Guo
- 1 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology , Fengtai District, Beijing, China
| | - Ran Liu
- 1 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology , Fengtai District, Beijing, China
| | - Gang Wang
- 3 Zhejiang Entry-Exit Inspection and Quarantine Bureau of the People's Republic of China, Hangzhou, China
| | - Minghao Zhou
- 2 Department of Disinfection and Vector Control, Jiangsu Provincial Center for Disease Control and Prevention , Gulou District, Nanjing, China
| | - Tongyan Zhao
- 1 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology , Fengtai District, Beijing, China
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Longbottom J, Browne AJ, Pigott DM, Sinka ME, Golding N, Hay SI, Moyes CL, Shearer FM. Mapping the spatial distribution of the Japanese encephalitis vector, Culex tritaeniorhynchus Giles, 1901 (Diptera: Culicidae) within areas of Japanese encephalitis risk. Parasit Vectors 2017; 10:148. [PMID: 28302156 PMCID: PMC5356256 DOI: 10.1186/s13071-017-2086-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 03/10/2017] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Japanese encephalitis (JE) is one of the most significant aetiological agents of viral encephalitis in Asia. This medically important arbovirus is primarily spread from vertebrate hosts to humans by the mosquito vector Culex tritaeniorhynchus. Knowledge of the contemporary distribution of this vector species is lacking, and efforts to define areas of disease risk greatly depend on a thorough understanding of the variation in this mosquito's geographical distribution. RESULTS We assembled a contemporary database of Cx. tritaeniorhynchus presence records within Japanese encephalitis risk areas from formal literature and other relevant resources, resulting in 1,045 geo-referenced, spatially and temporally unique presence records spanning from 1928 to 2014 (71.9% of records obtained between 2001 and 2014). These presence data were combined with a background dataset capturing sample bias in our presence dataset, along with environmental and socio-economic covariates, to inform a boosted regression tree model predicting environmental suitability for Cx. tritaeniorhynchus at each 5 × 5 km gridded cell within areas of JE risk. The resulting fine-scale map highlights areas of high environmental suitability for this species across India, Nepal and China that coincide with areas of high JE incidence, emphasising the role of this vector in disease transmission and the utility of the map generated. CONCLUSIONS Our map contributes towards efforts determining the spatial heterogeneity in Cx. tritaeniorhynchus distribution within the limits of JE transmission. Specifically, this map can be used to inform vector control programs and can be used to identify key areas where the prevention of Cx. tritaeniorhynchus establishment should be a priority.
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Affiliation(s)
- Joshua Longbottom
- Spatial Ecology & Epidemiology Group, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Annie J. Browne
- Spatial Ecology & Epidemiology Group, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - David M. Pigott
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA USA
| | - Marianne E. Sinka
- Oxford Long Term Ecology Laboratory, Department of Zoology, University of Oxford, Oxford, UK
| | - Nick Golding
- Quantitative & Applied Ecology Group, School of BioSciences, University of Melbourne, Parkville, VIC Australia
| | - Simon I. Hay
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA USA
- Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Catherine L. Moyes
- Spatial Ecology & Epidemiology Group, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Freya M. Shearer
- Spatial Ecology & Epidemiology Group, Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
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Hegde NR, Gore MM. Japanese encephalitis vaccines: Immunogenicity, protective efficacy, effectiveness, and impact on the burden of disease. Hum Vaccin Immunother 2017; 13:1-18. [PMID: 28301270 DOI: 10.1080/21645515.2017.1285472] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Japanese encephalitis (JE) is a serious public health concern in most of Asia. The disease is caused by JE virus (JEV), a flavivirus transmitted by Culex mosquitoes. Several vaccines have been developed to control JE in endemic areas as well as to protect travelers and military personnel who visit or are commissioned from non-endemic to endemic areas. The vaccines include inactivated vaccines produced in mouse brain or cell cultures, live attenuated vaccines, and a chimeric vaccine based on the live attenuated yellow fever virus 17D vaccine strain. All the marketed vaccines belong to the JEV genotype III, but have been shown to be efficacious against other genotypes and strains, with varying degrees of cross-neutralization, albeit at levels deemed to be protective. The protective responses have been shown to last three or more years, depending on the type of vaccine and the number of doses. This review presents a brief account of the different JE vaccines, their immunogenicity and protective ability, and the impact of JE vaccines in reducing the burden of disease in endemic countries.
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Affiliation(s)
- Nagendra R Hegde
- a Ella Foundation, Genome Valley , Turkapally, Shameerpet Mandal , Hyderabad , India
| | - Milind M Gore
- b National Institute of Virology, Indian Council of Medical Research , Pune , India
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Awais M, Wang K, Lin X, Qian W, Zhang N, Wang C, Wang K, Zhao L, Fu ZF, Cui M. TLR7 Deficiency Leads to TLR8 Compensative Regulation of Immune Response against JEV in Mice. Front Immunol 2017; 8:160. [PMID: 28265274 PMCID: PMC5316529 DOI: 10.3389/fimmu.2017.00160] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 01/31/2017] [Indexed: 12/28/2022] Open
Abstract
Japanese encephalitis virus (JEV) is a highly fatal pathogen to human beings. Toll-like receptor 7 (TLR7) plays a role as the first host defense against most single-stranded RNA flaviviruses. This study aims to investigate the role of TLR7 in inducing adaptive immune response in mice against JEV. In vitro and in vivo studies were conducted to examine the expression of toll-like receptors (TLRs) in mice. After JEV infection, physical parameters of mice (survival rate and body weight) were evaluated, and organs or cells were collected for further analysis. The expression of TLR7 was increased significantly as compare to other TLR molecules post-JEV infection. The expression of CD80, CD86, and CD273 on bone marrow-derived dendritic cells was increased significantly in TLR7−/− mice. Furthermore, viral load was also increased significantly in TLR7−/− mice as compare to C57BL/6 mice. But there was no significant difference among survival rate and body weight in TLR7−/− mice as compare to C57BL/6. Interestingly, we also found that TLR8 was upregulated in TLR7−/− mice. The study concluded that TLR8 was upregulated in TLR7-deficient mice, and it might play a compensatory role in the immune response in TLR7−/− mice.
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Affiliation(s)
- Muhammad Awais
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University , Wuhan , China
| | - Ke Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University , Wuhan , China
| | - Xianwu Lin
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University , Wuhan , China
| | - Wenjie Qian
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University , Wuhan , China
| | - Nan Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University , Wuhan , China
| | - Chong Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University , Wuhan , China
| | - Kunlun Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University , Wuhan , China
| | - Ling Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University , Wuhan , China
| | - Zhen F Fu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China; Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Min Cui
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University , Wuhan , China
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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: 102] [Impact Index Per Article: 14.6] [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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European Aedes albopictus and Culex pipiens Are Competent Vectors for Japanese Encephalitis Virus. PLoS Negl Trop Dis 2017; 11:e0005294. [PMID: 28085881 PMCID: PMC5268654 DOI: 10.1371/journal.pntd.0005294] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 01/26/2017] [Accepted: 01/02/2017] [Indexed: 11/19/2022] Open
Abstract
Background Japanese encephalitis virus (JEV) is the causative agent of Japanese encephalitis, the leading cause of viral encephalitis in Asia. JEV transmission cycle involves mosquitoes and vertebrate hosts. The detection of JEV RNA in a pool of Culex pipiens caught in 2010 in Italy raised the concern of a putative emergence of the virus in Europe. We aimed to study the vector competence of European mosquito populations, such as Cx. pipiens and Aedes albopictus for JEV genotypes 3 and 5. Findings After oral feeding on an infectious blood meal, mosquitoes were dissected at various times post-virus exposure. We found that the peak for JEV infection and transmission was between 11 and 13 days post-virus exposure. We observed a faster dissemination of both JEV genotypes in Ae. albopictus mosquitoes, when compared with Cx. pipiens mosquitoes. We also dissected salivary glands and collected saliva from infected mosquitoes and showed that Ae. albopictus mosquitoes transmitted JEV earlier than Cx. pipiens. The virus collected from Ae. albopictus and Cx. pipiens saliva was competent at causing pathogenesis in a mouse model for JEV infection. Using this model, we found that mosquito saliva or salivary glands did not enhance the severity of the disease. Conclusions In this study, we demonstrated that European populations of Ae. albopictus and Cx. pipiens were efficient vectors for JEV transmission. Susceptible vertebrate species that develop high viremia are an obligatory part of the JEV transmission cycle. This study highlights the need to investigate the susceptibility of potential JEV reservoir hosts in Europe, notably amongst swine populations and local water birds. Japanese encephalitis virus (JEV) is the leading cause of viral encephalitis in Asia. JEV is maintained in a cycle involving mosquitoes and vertebrate hosts, mainly pigs and wading birds. Humans can be infected when bitten by an infected mosquito. Culex tritaeniorhynchus is the main vector of the disease in tropical and subtropical areas. The recent detection of JEV in birds and mosquitoes collected in Northern Italy has led us to evaluate the putative emergence of this arboviral disease in Europe. For this purpose, we have tested the competence of European populations of Cx. pipiens and Aedes albopictus to transmit this virus in a laboratory setting. We showed that these local mosquitoes could be infected and were capable of transmitting a pathogenic virus to mice. It is thus urgent to evaluate the risks of JEV emergence in European regions displaying a favorable environment for mosquito vectors, susceptible pigs and wading birds.
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Kim HC, Kim MS, Choi KS, Hwang DU, Johnson JL, Klein TA. Comparison of Adult Mosquito Black-Light and Light-Emitting Diode Traps at Three Cowsheds Located in Malaria-Endemic Areas of the Republic of Korea. JOURNAL OF MEDICAL ENTOMOLOGY 2017; 54:221-228. [PMID: 28082650 DOI: 10.1093/jme/tjw136] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 08/02/2016] [Indexed: 06/06/2023]
Abstract
Adult mosquito surveillance and field trials evaluated selected commercially available ultraviolet black-light (BL) and light-emitting diode (LED) traps at three sites where vivax malaria is endemic from May to October 2015 in northwestern Republic of Korea. Collections totaled 283,929 adult mosquitoes (280,355 [98.74%] females and 3,574 [1.26%] males) comprising 17 species (including six members of the Anopheles Hyrcanus Group) belonging to six genera. The four most predominant female species collected were Aedes vexans nipponii (Theobald) (83.84%), followed by Anopheles Hyrcanus Group (13.66%), Culex pipiens Group (1.67%), and Culex tritaeniorhynchus Giles (0.54%). Overall, LED traps (188,125) collected significantly more female mosquitoes compared with BL traps (92,230; P = 0.0001, P < 0.05). Results from these field evaluations significantly enhance vector and disease surveillance efforts, especially for the primary vectors of malaria (Anopheles Hyrcanus Group) and Japanese encephalitis (Cx. tritaeniorhynchus).
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Affiliation(s)
- Heung-Chul Kim
- 5th Medical Detachment, 168th Multifunctional Medical Battalion 65 Medical Brigade, Unit 15247, APO AP, 96205-5247 (; ; )
| | - Myung-Soon Kim
- 5th Medical Detachment, 168th Multifunctional Medical Battalion 65 Medical Brigade, Unit 15247, APO AP, 96205-5247 (; ; )
| | - Kwang-Shik Choi
- College of Natural Science, Kyungpook National University, Daegu 41566, Republic of Korea (; )
| | - Do-Un Hwang
- College of Natural Science, Kyungpook National University, Daegu 41566, Republic of Korea (; )
| | - Jaree L Johnson
- 5th Medical Detachment, 168th Multifunctional Medical Battalion 65 Medical Brigade, Unit 15247, APO AP, 96205-5247 (; ; )
| | - Terry A Klein
- MEDDAC-K/65th Medical Brigade, Unit 15281, APO AP 96205-5281
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Huang SH, Lien JC, Chen CJ, Liu YC, Wang CY, Ping CF, Lin YF, Huang AC, Lin CW. Antiviral Activity of a Novel Compound CW-33 against Japanese Encephalitis Virus through Inhibiting Intracellular Calcium Overload. Int J Mol Sci 2016; 17:ijms17091386. [PMID: 27563890 PMCID: PMC5037666 DOI: 10.3390/ijms17091386] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 07/26/2016] [Accepted: 08/18/2016] [Indexed: 01/31/2023] Open
Abstract
Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, has five genotypes (I, II, III, IV, and V). JEV genotype I circulates widely in some Asian countries. However, current JEV vaccines based on genotype III strains show low neutralizing capacities against genotype I variants. In addition, JE has no specific treatment, except a few supportive treatments. Compound CW-33, an intermediate synthesized derivative of furoquinolines, was investigated for its antiviral activities against JEV in this study. CW-33 exhibited the less cytotoxicity to Syrian baby hamster kidney (BHK-21) and human medulloblastoma (TE761) cells. CW-33 dose-dependently reduced the cytopathic effect and apoptosis of JEV-infected cells. Supernatant virus yield assay pinpointed CW-33 as having potential anti-JEV activity with IC50 values ranging from 12.7 to 38.5 μM. Time-of-addition assay with CW-33 indicated that simultaneous and post-treatment had no plaque reduction activity, but continuous and simultaneous treatments proved to have highly effective antiviral activity, with IC50 values of 32.7 and 48.5 μM, respectively. CW-33 significantly moderated JEV-triggered Ca2+ overload, which correlated with the recovery of mitochondria membrane potential as well as the activation of Akt/mTOR and Jak/STAT1 signals in treated infected cells. Phosphopeptide profiling by LC-MS/MS revealed that CW-33 upregulated proteins from the enzyme modulator category, such as protein phosphatase inhibitor 2 (I-2), Rho GTPase-activating protein 35, ARF GTPase-activating protein GIT2, and putative 3-phosphoinositide-dependent protein kinase 2. These enzyme modulators identified were associated with the activation of Akt/mTOR and Jak/STAT1 signals. Meanwhile, I-2 treatment substantially inhibited the apoptosis of JEV-infected cells. The results demonstrated that CW-33 exhibited a significant potential in the development of anti-JEV agents.
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Affiliation(s)
- Su-Hua Huang
- Department of Biotechnology, Asia University, Wufeng, Taichung 413, Taiwan.
| | - Jin-Cherng Lien
- School of Pharmacy, China Medical University, Taichung 404, Taiwan.
| | - Chao-Jung Chen
- Proteomics Core Laboratory, Department of Medical Research, China Medical University Hospital, Taichung 404, Taiwan.
| | - Yu-Ching Liu
- Proteomics Core Laboratory, Department of Medical Research, China Medical University Hospital, Taichung 404, Taiwan.
| | - Ching-Ying Wang
- Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung 404, Taiwan.
| | - Chia-Fong Ping
- Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung 404, Taiwan.
| | - Yu-Fong Lin
- Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung 404, Taiwan.
| | - An-Cheng Huang
- Department of Nursing, St. Mary's Junior College of Medicine, Nursing and Management, Yilan County 266, Taiwan.
| | - Cheng-Wen Lin
- Department of Biotechnology, Asia University, Wufeng, Taichung 413, Taiwan.
- Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung 404, Taiwan.
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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: 30] [Impact Index Per Article: 3.8] [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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Kim HJ, Lyoo HR, Park JY, Choi JS, Lee JY, Jeoung HY, Cho YS, Cho IS, Yoo HS. Surveillance of Rift Valley Fever Virus in Mosquito Vectors of the Republic of Korea. Vector Borne Zoonotic Dis 2016; 16:131-5. [DOI: 10.1089/vbz.2015.1843] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Hyun-Joo Kim
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - Hye-Rhyoung Lyoo
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - Jee-Yong Park
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - Jeong-Soo Choi
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - Ji-Youn Lee
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - Hye-Young Jeoung
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - Yun-Sang Cho
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - In-Soo Cho
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | - Han Sang Yoo
- College of Veterinary Medicine and BK21 PLUS, Seoul National University, Seoul, Republic of Korea
- Institute of Green Bio Science and Technology, Seoul National University, Pyeongchang, Republic of Korea
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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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Lee JH, Seo HJ, Park JY, Kim SH, Cho YS, Kim YJ, Cho IS, Jeoung HY. Detection and differentiation of Schmallenberg, Akabane and Aino viruses by one-step multiplex reverse-transcriptase quantitative PCR assay. BMC Vet Res 2015; 11:270. [PMID: 26497392 PMCID: PMC4619357 DOI: 10.1186/s12917-015-0582-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 10/14/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Schmallenberg virus (SBV), Akabane virus (AKAV) and Aino virus (AINV) are members of the Simbu serogroup within the genus Orthobunyavirus, family Bunyaviridae, which can cause reproductive disorders including abortion, stillbirth and congenital malformation in ruminants. Because, the clinical signs are similar, confirmatory diagnosis requires viral detection to differentiate infection between these three viruses. METHODS In this study, a one-step multiplex reverse-transcriptase quantitative PCR (one-step mRT-qPCR) was developed for the simultaneous detection and differentiation of SBV, AKAV and AINV. RESULTS The detection limit of the one-step mRT-qPCR for SBV, AKAV and AINV were 2.4 copies (10 (0.6) TCID 50/ml), 96.2 copies (10 (1.5) TCID 50/ml) and 52.3 copies (10 (1.2) TCID 50/ml), respectively. Various field samples such as bovine serum, bovine whole blood, bovine brain, goat serum and Culicoides were analyzed using the one-step mRT-qPCR and compared with previously published RT-qPCRs. The test results of the field samples were identical for the one-step mRT-qPCR and RT-qPCRs, which showed all samples to be negative for SBV, AKAV and AINV, except for one bovine brain sample (1/123) that was positive for AKAV. CONCLUSION The one-step mRT-qPCR allows for the simultaneous detection of three viral pathogens (SBV, AKAV and AINV) that cause reproductive failure.
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Affiliation(s)
- Ji-Hye Lee
- Animal and Plant Quarantine Agency, Anyang, Gyeonggi-do, 430-824, Republic of Korea.
| | - Hyun-Ji Seo
- Animal and Plant Quarantine Agency, Anyang, Gyeonggi-do, 430-824, Republic of Korea.
| | - Jee-Yong Park
- Animal and Plant Quarantine Agency, Anyang, Gyeonggi-do, 430-824, Republic of Korea.
| | - Sung-Hee Kim
- Animal and Plant Quarantine Agency, Anyang, Gyeonggi-do, 430-824, Republic of Korea.
| | - Yun Sang Cho
- Animal and Plant Quarantine Agency, Anyang, Gyeonggi-do, 430-824, Republic of Korea.
| | - Yong-Joo Kim
- Animal and Plant Quarantine Agency, Anyang, Gyeonggi-do, 430-824, Republic of Korea.
| | - In-Soo Cho
- Animal and Plant Quarantine Agency, Anyang, Gyeonggi-do, 430-824, Republic of Korea.
| | - Hye-Young Jeoung
- Animal and Plant Quarantine Agency, Anyang, Gyeonggi-do, 430-824, Republic of Korea.
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Han N, Adams J, Fang W, Liu SQ, Rayner S. Investigation of the genotype III to genotype I shift in Japanese encephalitis virus and the impact on human cases. Virol Sin 2015; 30:277-89. [PMID: 26311492 DOI: 10.1007/s12250-015-3621-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 08/13/2015] [Indexed: 11/28/2022] Open
Abstract
Japanese encephalitis is a mosquito borne disease and is the leading cause of viral encephalitis in the Asia-Pacific area. The causative agent, Japanese encephalitis virus (JEV) can be phylogenetically classified into five genotypes based on nucleotide sequence. In recent years, genotype I (GI) has displaced genotype III (GIII) as the dominant lineage, but the mechanisms behind this displacement event requires elucidation. In an earlier study, we compared host variation over time between the two genotypes and observed that GI appears to have evolved to achieve more efficient infection in hosts in the replication cycle, with the tradeoff of reduced infectivity in secondary hosts such as humans. To further investigate this phenomenon, we collected JEV surveillance data on human cases and, together with sequence data, and generated genotype/case profiles from seven Asia-Pacific countries and regions to characterize the GI/GIII displacement event. We found that, when comprehensive and consistent vaccination and surveillance data was available, and the GIII to GI shift occurred within a well-defined time period, there was a statistically significant drop in JEV human cases. Our findings provide further support for the argument that GI is less effective in infecting humans, who represent a dead end host. However, experimental investigation is necessary to confirm this hypothesis. The study highlights the value of alternative approaches to investigation of epidemics, as well as the importance of effective data collection for disease surveillance and control.
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Affiliation(s)
- Na Han
- State Key Laboratory for Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China
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Eick-Cost AA, Hu Z, Klein TA, Putnak RJ, Jarman RG. Seroconversion to Japanese Encephalitis Virus Among U.S. Infantry Forces in Korea. Am J Trop Med Hyg 2015; 93:1052-4. [PMID: 26240157 DOI: 10.4269/ajtmh.15-0307] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 06/29/2015] [Indexed: 11/07/2022] Open
Abstract
Japanese encephalitis virus (JEV) is endemic in the Republic of Korea (ROK), posing a medical threat to more than 29,000 U.S. Forces military personnel currently deployed in the ROK. The objective of this study was to provide data on the risk of JEV exposure among U.S. Forces in the ROK. One thousand U.S. Army Soldiers were randomly selected for the study from the cohort of infantry Soldiers deployed in the ROK for a period of at least 330 days from 2008 to 2011. Pre- and post-deployment serum specimens were tested for the presence of JEV antibodies by plaque reduction neutralization test. A total of 2/1,000 (0.2%) U.S. Army Soldiers post-deployment specimens tested positive for JEV antibody. Results from the pre-deployment specimens indicated one true seroconversion and one with titers suggestive of a JEV infection. These results indicate a low, but nonzero risk of JEV exposure among U.S. Army Soldiers in the ROK.
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Affiliation(s)
- Angelia A Eick-Cost
- Epidemiology and Analysis Division, Armed Forces Health Surveillance Center, Silver Spring, Maryland; Force Health Protection and Preventive Medicine, 65th Medical Brigade, Seoul, Republic of Korea; Viral Disease Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Zheng Hu
- Epidemiology and Analysis Division, Armed Forces Health Surveillance Center, Silver Spring, Maryland; Force Health Protection and Preventive Medicine, 65th Medical Brigade, Seoul, Republic of Korea; Viral Disease Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Terry A Klein
- Epidemiology and Analysis Division, Armed Forces Health Surveillance Center, Silver Spring, Maryland; Force Health Protection and Preventive Medicine, 65th Medical Brigade, Seoul, Republic of Korea; Viral Disease Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Robert J Putnak
- Epidemiology and Analysis Division, Armed Forces Health Surveillance Center, Silver Spring, Maryland; Force Health Protection and Preventive Medicine, 65th Medical Brigade, Seoul, Republic of Korea; Viral Disease Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
| | - Richard G Jarman
- Epidemiology and Analysis Division, Armed Forces Health Surveillance Center, Silver Spring, Maryland; Force Health Protection and Preventive Medicine, 65th Medical Brigade, Seoul, Republic of Korea; Viral Disease Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
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Nah JJ, Yang DK, Kim HH, Song JY. The present and future of veterinary vaccines for Japanese encephalitis in Korea. Clin Exp Vaccine Res 2015; 4:130-6. [PMID: 26273571 PMCID: PMC4524897 DOI: 10.7774/cevr.2015.4.2.130] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 05/03/2015] [Accepted: 05/20/2015] [Indexed: 12/30/2022] Open
Abstract
Japanese encephalitis (JE) is a mosquito-borne zoonotic disease that affects approximately 50,000 people annually in Asia, causing 10,000 deaths. Considering the role of pigs as the virus-amplifying host and the economic loss in the swine industry, JE is an important disease for both public and animal health. A nationwide JE virus (JEV) vaccination program has been conducted annually for more than 30 years to prevent severe reproductive disorders in the Korean sow population. Remarkable progress in molecular biology has made it possible to analyze the genome of the vaccine strain at the nucleotide and amino acid levels. However, the scientific record of the current JEV veterinary vaccine has not been reported. Therefore, this article outlines the current JEV vaccine strain used in animals and discusses future directions for developing new veterinary JEV vaccines.
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Affiliation(s)
- Jin-Ju Nah
- Animal and Plant Quarantine Agency, MAFRA, Anyang, Korea
| | - Dong-Kun Yang
- Animal and Plant Quarantine Agency, MAFRA, Anyang, Korea
| | - Ha-Hyun Kim
- Animal and Plant Quarantine Agency, MAFRA, Anyang, Korea
| | - Jae-Young Song
- Animal and Plant Quarantine Agency, MAFRA, Anyang, Korea
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Tajima S, Yagasaki K, Kotaki A, Tomikawa T, Nakayama E, Moi ML, Lim CK, Saijo M, Kurane I, Takasaki T. In vitro growth, pathogenicity and serological characteristics of the Japanese encephalitis virus genotype V Muar strain. J Gen Virol 2015; 96:2661-2669. [PMID: 26048886 DOI: 10.1099/vir.0.000213] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The characteristics of genotype V Japanese encephalitis virus (GV JEV) remain poorly understood as only two strains have been isolated to date. In this study, we examined the effects of the GV JEV Muar strain on in vitro growth and pathogenicity in mice; we also evaluated the efficacy of inactivated JEV vaccines against the Muar strain. Although growth of the Muar strain in mouse neuroblastoma N18 cells was clearly worse than that of the GIII Beijing-1 and GI Mie/41/2002 strains, neuroinvasiveness of the Muar strain was similar to that of the Beijing-1 strain and significantly higher than that of the Mie/41/2002 strain. The results of a plaque reduction neutralization test suggested that the neutralization ability of the JEV vaccines against the Muar strain was reduced compared with the GI and GIII strains. However, the protection potency of the JEV vaccine against the Muar strain was similar to that for the Beijing-1 strain in mice. Our data indicate that GV JEV has unique growth, virulence and antigenicity features.
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Affiliation(s)
- Shigeru Tajima
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Kazumi Yagasaki
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Akira Kotaki
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Takumi Tomikawa
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Eri Nakayama
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Meng Ling Moi
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Chang-Kweng Lim
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Masayuki Saijo
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Ichiro Kurane
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Tomohiko Takasaki
- Department of Virology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
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Kim HJ, Park JY, Jeoung HY, Yeh JY, Cho YS, Choi JS, Lee JY, Cho IS, Yoo HS. Serological surveillance studies confirm the Rift Valley fever virus free status in South Korea. Trop Anim Health Prod 2015; 47:1427-30. [PMID: 26024956 DOI: 10.1007/s11250-015-0858-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 05/18/2015] [Indexed: 11/27/2022]
Abstract
Rift Valley fever is a mosquito-borne zoonotic disease of domestic ruminants. This disease causes abortions in pregnant animals, and it has a high mortality rate in newborn animals. Recently, a Rift Valley fever virus (RVFV) outbreak in the Arabian Peninsula increased its potential spread to new regions worldwide. In non-endemic or disease-free countries, early detection and surveillance are important for preventing the introduction of RVFV. In this study, a serological surveillance was conducted to detect antibodies against RVFV. A total of 2382 serum samples from goats and cattle were randomly collected from nine areas in South Korea from 2011 to 2013. These samples were tested for antibodies against RVFV, using commercial ELISA kits. None of the goats and cattle were positive for antibodies against RVFV. This finding suggests that this disease is not present in South Korea, and furthermore presents the evidence of the RVFV-free status of this country.
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Affiliation(s)
- Hyun Joo Kim
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Anyang, 430-757, Republic of Korea
| | - Jee-Yong Park
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Anyang, 430-757, Republic of Korea
| | - Hye-Young Jeoung
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Anyang, 430-757, Republic of Korea
| | - Jung-Yong Yeh
- Incheon National University, Incheon, 406-772, Republic of Korea
| | - Yun-Sang Cho
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Anyang, 430-757, Republic of Korea
| | - Jeong-Soo Choi
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Anyang, 430-757, Republic of Korea
| | - Ji-Youn Lee
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Anyang, 430-757, Republic of Korea
| | - In-Soo Cho
- Foreign Animal Disease Division, Animal and Plant Quarantine Agency, 175 Anyang-ro, Anyang, 430-757, Republic of Korea
| | - Han-Sang Yoo
- Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul, 151-742, Republic of Korea.
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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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Comparison of genotypes I and III in Japanese encephalitis virus reveals distinct differences in their genetic and host diversity. J Virol 2014; 88:11469-79. [PMID: 25056890 DOI: 10.1128/jvi.02050-14] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
UNLABELLED Japanese encephalitis (JE) is an arthropod-borne disease associated with the majority of viral encephalitis cases in the Asia-Pacific region. The causative agent, Japanese encephalitis virus (JEV), has been phylogenetically divided into five genotypes. Recent surveillance data indicate that genotype I (GI) is gradually replacing genotype III (GIII) as the dominant genotype. To investigate the mechanism behind the genotype shift and the potential consequences in terms of vaccine efficacy, human cases, and virus dissemination, we collected (i) all full-length and partial JEV molecular sequences and (ii) associated genotype and host information comprising a data set of 873 sequences. We then examined differences between the two genotypes at the genetic and epidemiological level by investigating amino acid mutations, positive selection, and host range. We found that although GI is dominant, it has fewer sites predicted to be under positive selection, a narrower host range, and significantly fewer human isolates. For the E protein, the sites under positive selection define a haplotype set for each genotype that shows striking differences in their composition and diversity, with GIII showing significantly more variety than GI. Our results suggest that GI has displaced GIII by achieving a replication cycle that is more efficient but is also more restricted in its host range. IMPORTANCE Japanese encephalitis is an arthropod-borne disease associated with the majority of viral encephalitis cases in the Asia-Pacific region. The causative agent, Japanese encephalitis virus (JEV), has been divided into five genotypes based on sequence similarity. Recent data indicate that genotype I (GI) is gradually replacing genotype III (GIII) as the dominant genotype. Understanding the reasons behind this shift and the potential consequences in terms of vaccine efficacy, human cases, and virus dissemination is important for controlling the spread of the virus and reducing human fatalities. We collected all available full-length and partial JEV molecular sequences and associated genotype and host information. We then examined differences between the two genotypes at the genetic and epidemiological levels by investigating amino acid mutations, positive selection, and host range. Our results suggest that GI has displaced GIII by achieving a replication cycle that is more efficient but more restricted in host range.
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50
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Yang DK, Nah JJ, Kim HH, Song JY. Inactivated genotype 1 Japanese encephalitis vaccine for swine. Clin Exp Vaccine Res 2014; 3:212-9. [PMID: 25003095 PMCID: PMC4083074 DOI: 10.7774/cevr.2014.3.2.212] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 04/14/2014] [Accepted: 04/20/2014] [Indexed: 11/15/2022] Open
Abstract
PURPOSE Japanese encephalitis is a reproductive disorder caused by Japanese encephalitis virus (JEV) in swine. Recent genotype (G) shift phenomenon (G3 to G1) in the Asia-wide has posed a challenge for proper prevention by the current vaccine strain. Thus, new kinds of JEV G1 vaccines with enhanced immunogenicity have been required for pigs. MATERIALS AND METHODS Recombinant porcine granulocyte monocyte-colony stimulating factor (reporGM-CSF) protein was expressed in Spodoptera frugiperda (Sf-9) cells using baculovirus expression system. Two kinds of trials with inactivated JEV vaccines containing IMS1313 adjuvant (Seppic, France) were prepared with or without reporGM-CSF protein. Safety and immunogenicity of the pigs inoculated with the JEV vaccines via intramuscular route was evaluated for 28 days after inoculation. RESULTS Mice, guinea pigs, and fattening pigs inoculated with the inactivated vaccine showed no signs for 14 and 21 days. Both hemagglutination inhibition and plaque reduction neutralizing antibody titers were significantly higher in pigs immunized with the vaccine containing reporGM-CSF protein after boosting. However, on the side of vaccine efficacy, most mice (87%) immunized with the inactivated JEV vaccine survived after virulent JEV challenge. Whereas the group with the vaccine containing reporGM-CSF protein showed lower protective effects than the vaccine alone for the biological activity of the GM-CSF depending on species specific. CONCLUSION Our data indicate that animals inoculated with the JEV vaccines was safe and pigs inoculated with inactivated JEV vaccine containing reporGM-CSF protein showed higher humoral immune responses than that of inactivated JEV vaccine without reporGM-CSF protein.
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Affiliation(s)
- Dong-Kun Yang
- Viral Disease Division, Animal and Plant Quarantine Agency, Ministry of Agriculture, Food and Rural Affairs (MAFRA), Anyang, Korea
| | - Jin-Ju Nah
- Viral Disease Division, Animal and Plant Quarantine Agency, Ministry of Agriculture, Food and Rural Affairs (MAFRA), Anyang, Korea
| | - Ha-Hyun Kim
- Viral Disease Division, Animal and Plant Quarantine Agency, Ministry of Agriculture, Food and Rural Affairs (MAFRA), Anyang, Korea
| | - Jae-Young Song
- Viral Disease Division, Animal and Plant Quarantine Agency, Ministry of Agriculture, Food and Rural Affairs (MAFRA), Anyang, Korea
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