1
|
Krambrich J, Akaberi D, Lindahl JF, Lundkvist Å, Hesson JC. Vector competence of Swedish Culex pipiens mosquitoes for Japanese encephalitis virus. Parasit Vectors 2024; 17:220. [PMID: 38741172 DOI: 10.1186/s13071-024-06269-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 04/02/2024] [Indexed: 05/16/2024] Open
Abstract
BACKGROUND Japanese encephalitis virus (JEV) is an emerging mosquito-borne Orthoflavivirus that poses a significant public health risk in many temperate and tropical regions in Asia. Since the climate in some endemic countries is similar to temperate climates observed in Europe, understanding the role of specific mosquito species in the transmission of JEV is essential for predicting and effectively controlling the potential for the introduction and establishment of JEV in Europe. METHODS This study aimed to investigate the vector competence of colonized Culex pipiens biotype molestus mosquitoes for JEV. The mosquitoes were initially collected from the field in southern Sweden. The mosquitoes were offered a blood meal containing the Nakayama strain of JEV (genotype III), and infection rates, dissemination rates, and transmission rates were evaluated at 14, 21, and 28 days post-feeding. RESULTS The study revealed that colonized Swedish Cx. pipiens are susceptible to JEV infection, with a stable infection rate of around 10% at all timepoints. However, the virus was only detected in the legs of one mosquito at 21 days post-feeding, and no mosquito saliva contained JEV. CONCLUSIONS Overall, this research shows that Swedish Cx. pipiens can become infected with JEV, and emphasizes the importance of further understanding of the thresholds and barriers for JEV dissemination in mosquitoes.
Collapse
Affiliation(s)
- Janina Krambrich
- Zoonosis Science Center, Department of Medical Biochemistry and Microbiology, Uppsala University, Husargatan 3, 75237, Uppsala, Sweden.
| | - Dario Akaberi
- Zoonosis Science Center, Department of Medical Biochemistry and Microbiology, Uppsala University, Husargatan 3, 75237, Uppsala, Sweden
| | - Johanna F Lindahl
- Zoonosis Science Center, Department of Medical Biochemistry and Microbiology, Uppsala University, Husargatan 3, 75237, Uppsala, Sweden
- International Livestock Research Institute, Hanoi, Vietnam
- Department of Animal Health and Antibiotic Strategies, Swedish National Veterinary Institute, Uppsala, Sweden
| | - Åke Lundkvist
- Zoonosis Science Center, Department of Medical Biochemistry and Microbiology, Uppsala University, Husargatan 3, 75237, Uppsala, Sweden
| | - Jenny C Hesson
- Zoonosis Science Center, Department of Medical Biochemistry and Microbiology, Uppsala University, Husargatan 3, 75237, Uppsala, Sweden
- Biologisk Myggkontroll, Nedre Dalälvens Utvecklings AB, Gysinge, Sweden
| |
Collapse
|
2
|
Li W, Feng Y, Zhong H, Jiang M, Zhang J, Lin S, Chen N, He S, Zhang K, Fu S, Wang H, Liang G. Incongruence between confirmed and suspected clinical cases of Japanese encephalitis virus infection. Front Cell Infect Microbiol 2024; 14:1302314. [PMID: 38343888 PMCID: PMC10853334 DOI: 10.3389/fcimb.2024.1302314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 01/09/2024] [Indexed: 02/15/2024] Open
Abstract
Background Japanese encephalitis (JE) is a notifiable infectious disease in China. Information on every case of JE is reported to the superior health administration department. However, reported cases include both laboratory-confirmed and clinically diagnosed cases. This study aimed to differentiate between clinical and laboratory-confirmed cases of Japanese encephalitis virus (JEV) infection, and improve the accuracy of reported JE cases by analyzing the acute-phase serum and cerebrospinal fluid of all reported JE cases in the Sichuan province from 2012 to 2022. Methods All acute-phase serum and/or cerebrospinal fluid samples of the reported JE cases were screened for IgM(ImmunoglobulinM)to JEV using the enzyme-linked immunosorbent assay (ELISA), and the detection of the viral genes of JEV and 9 other pathogens including enterovirus (EV), using reverse transcription PCR was attempted. Epidemiological analyses of JE and non-JE cases based on sex, age, onset time, and geographical distribution were also performed. Results From 2012 to 2022, 1558 JE cases were reported in the Sichuan province. The results of serological (JEV-specific IgM) and genetic testing for JEV showed that 81% (1262/1558) of the reported cases were confirmed as JEV infection cases (laboratory-confirmed cases). Among the 296 cases of non-JEV infection, 6 viruses were detected in the cerebrospinal fluid in 62 cases, including EV and the Epstein-Barr virus (EBV), constituting 21% (62/296) of all non-JE cases. Among the 62 non-JEV infection cases with confirmed pathogens, infections with EV and EBV included 17 cases each, herpes simplex virus (HSV-1/2) included 14 cases, varicella- zoster virus included 6 cases, mumps virus included 2 cases, and human herpes viruses-6 included 1 case. Additionally, there were five cases involving mixed infections (two cases of EV/EBV, one case of HSV-1/HSV-2, one case of EBV/HSV-1, and one case of EV/herpes viruses-6). The remaining 234 cases were classified as unknown viral encephalitis cases. Our analysis indicated that those aged 0-15 y were the majority of the patients among the 1558 reported JE cases. However, the incidence of laboratory-confirmed JE cases in the >40 y age group has increased in recent years. The temporal distribution of laboratory-confirmed cases of JE revealed that the majority of cases occurred from May to September each year, with the highest incidence in August. Conclusion The results of this study indicate that there is a certain discrepancy between clinically diagnosed and laboratory-confirmed cases of JE. Each reported case should be based on laboratory detection results, which is of great importance in improving the accuracy of case diagnosis and reducing misreporting. Our results are not only important for addressing JE endemic to the Sichuan province, but also provide a valuable reference for the laboratory detection of various notifiable infectious diseases in China and other regions outside China.
Collapse
Affiliation(s)
- Wei Li
- Institute of Microbiological Detection and Analyses, Sichuan Center for Disease Control and Prevention, Chengdu, China
| | - Yuliang Feng
- Institute of Microbiological Detection and Analyses, Sichuan Center for Disease Control and Prevention, Chengdu, China
| | - Hongrong Zhong
- Institute of Microbiological Detection and Analyses, Sichuan Center for Disease Control and Prevention, Chengdu, China
| | - Mingfeng Jiang
- Institute of Microbiological Detection and Analyses, Sichuan Center for Disease Control and Prevention, Chengdu, China
| | - Jiake Zhang
- Institute of Microbiological Detection and Analyses, Sichuan Center for Disease Control and Prevention, Chengdu, China
| | - Shihua Lin
- Institute of Microbiological Detection and Analyses, Sichuan Center for Disease Control and Prevention, Chengdu, China
| | - Na Chen
- Institute of Microbiological Detection and Analyses, Sichuan Center for Disease Control and Prevention, Chengdu, China
| | - Shusen He
- Institute of Microbiological Detection and Analyses, Sichuan Center for Disease Control and Prevention, Chengdu, China
| | - Kai Zhang
- Institute of Immunization Programme, Sichuan Center for Disease Control and Prevention, Chengdu, China
| | - Shihong Fu
- Department of Arbovirus, National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Huanyu Wang
- Department of Arbovirus, National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Guodong Liang
- Department of Arbovirus, National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| |
Collapse
|
3
|
Jeffries CL, Tantely LM, Kadriaj P, Blagrove MSC, Lytra I, Orsborne J, Al-Amin HM, Mohammed AR, Alam MS, Girod R, Afrane YA, Bino S, Robert V, Boyer S, Baylis M, Velo E, Hughes GL, Walker T. Mitochondrial and microbial diversity of the invasive mosquito vector species Culex tritaeniorhynchus across its extensive inter-continental geographic range. Wellcome Open Res 2024; 9:18. [PMID: 38800519 PMCID: PMC11128058 DOI: 10.12688/wellcomeopenres.20761.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/28/2023] [Indexed: 05/29/2024] Open
Abstract
Background Culex (Cx.) tritaeniorhynchus is an invasive mosquito species with an extensive and expanding inter-continental distribution, currently reported across Asia, Africa, the Middle East, Europe and now Australia. It is an important vector of medical and veterinary pathogens which cause significant morbidity and mortality in human and animal populations. Across regions endemic for Japanese encephalitis virus (JEV), Cx. tritaeniorhynchus is considered the major vector and has also been shown to contribute to the transmission of several other zoonotic arboviruses including Rift Valley fever virus (RVFV) and West Nile virus (WNV). Methods In this study, we used laboratory vector competence experiments to determine if Cx. tritaeniorhynchus from a Southern European population were competent JEV vectors. We also obtained samples from multiple geographically dispersed Cx. tritaeniorhynchus populations from countries within Europe, Africa, Eurasia and Asia to perform phylogenetic analysis to measure the level of mitochondrial divergence using the cytochrome oxidase subunit 1 ( CO1) gene. We also undertook bacterial 16S rRNA gene amplicon sequencing to determine microbial diversity and used multi-locus sequence typing (MLST) to determine any evidence for the presence of strains of the naturally occurring endosymbiotic bacterium Wolbachia. Results Cx. tritaeniorhynchus from a Greek population were shown be be competent vectors of JEV with high levels of virus present in saliva. We found a signficant level of mitochondrial genetic diversity using the mosquito CO1 gene between geographically dispersed populations. Furthermore, we report diverse microbiomes identified by 16S rRNA gene amplicon sequencing within and between geographical populations. Evidence for the detection of the endosymbiotic bacteria Wolbachia was confirmed using Wolbachia-specific PCR and MLST. Conclusions This study enhances our understanding of the diversity of Cx. tritaeniorhynchus and the associated microbiome across its inter-continental range and highlights the need for greater surveillance of this invasive vector species in Europe.
Collapse
Affiliation(s)
- Claire L. Jeffries
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Luciano M Tantely
- Unite d'entomologie medicale, Institute Pasteur de Madagascar, Antanarivo, Madagascar
| | - Perparim Kadriaj
- Vector Control Unit, Control of Infectious Diseases Department, Institute of Public Health, Tirana, Albania
| | - Marcus S C Blagrove
- Department of Evolution, Ecology and Behaviour, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, England, UK
- Health Protection Research Unit on Emerging and Zoonotic Infections, University of Liverpool, Liverpool, England, UK
| | - Ioanna Lytra
- Department of Entomology and Agricultural Zoology, Benaki Phytopathological Institute, Athens, Greece
| | - James Orsborne
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Hasan Mohammad Al-Amin
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
- Berghofer Medical Research Institute, Queensland Institute of Medical Research, Brisbane, Australia
| | - Abdul Rahim Mohammed
- Department of Medical Microbiology, University of Ghana Medical School, University of Ghana, Accra, Greater Accra Region, Ghana
| | - Mohammad Shafiul Alam
- Infectious Diseases Division, International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
| | - Romain Girod
- Unite d'entomologie medicale, Institute Pasteur de Madagascar, Antanarivo, Madagascar
| | - Yaw A Afrane
- Department of Medical Microbiology, University of Ghana Medical School, University of Ghana, Accra, Greater Accra Region, Ghana
| | - Silvia Bino
- Vector Control Unit, Control of Infectious Diseases Department, Institute of Public Health, Tirana, Albania
| | - Vincent Robert
- MIVEGEC, CNRS, Institute of Research for Development (IRD), University of Montpellier, Montpellier, France
| | - Sebastien Boyer
- Unite d'entomologie medicale, Institute Pasteur de Madagascar, Antanarivo, Madagascar
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Matthew Baylis
- Health Protection Research Unit on Emerging and Zoonotic Infections, University of Liverpool, Liverpool, England, UK
- Department of Livestock and One Health, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, England, UK
| | - Enkelejda Velo
- Vector Control Unit, Control of Infectious Diseases Department, Institute of Public Health, Tirana, Albania
| | - Grant L Hughes
- Departments of Vector Biology and Tropical Disease Biology, Centre for Neglected Tropical Disease, University of Liverpool, Liverpool, England, UK
| | - Thomas Walker
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
- School of Life Sciences, University of Warwick, Coventry, England, UK
| |
Collapse
|
4
|
Dawah HA, Abdullah MA, Ahmad SK, Turner J, Azari-Hamidian S. An overview of the mosquitoes of Saudi Arabia (Diptera: Culicidae), with updated keys to the adult females. Zootaxa 2023; 5394:1-76. [PMID: 38220993 DOI: 10.11646/zootaxa.5394.1.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Indexed: 01/16/2024]
Abstract
Despite the fact that mosquito-borne infections have considerable consequences for public health in Saudi Arabia, there is neither a thorough review of the species that occur in the country nor updated keys for the identification of the adult females. In this study, species accounts are given for 49 Saudi Arabian mosquito species, as well as Aedes albopictus (Skuse), which is not recorded in Saudi Arabia, but is medically important and is found in some countries of the Middle East and North Africa. Taxonomic notes provide additional information for certain taxa and/or aid their identification.
Collapse
Affiliation(s)
- Hassan A Dawah
- Centre for Environmental Research and Studies; Jazan University; P.O. Box 2095; Jazan; Kingdom of Saudi Arabia.
| | - Mohammed A Abdullah
- Department of Biology; College of Science; King Khalid University; PO Box 9004; Abha-61413; Kingdom of Saudi Arabia.
| | - Syed Kamran Ahmad
- Department of Plant Protection; Faculty of Agricultural Sciences; Aligarh Muslim University; Aligarh; India.
| | - James Turner
- National Museum of Wales; Department of Natural Sciences; Entomology Section; Cardiff; CF10 3NP; UK.
| | - Shahyad Azari-Hamidian
- Research Center of Health and Environment; School of Health; Guilan University of Medical Sciences; Rasht; Iran; Department of Medical Parasitology; Mycology and Entomology; School of Medicine; Guilan University of Medical Sciences; Rasht; Iran.
| |
Collapse
|
5
|
Monath TP. Japanese Encephalitis: Risk of Emergence in the United States and the Resulting Impact. Viruses 2023; 16:54. [PMID: 38257754 PMCID: PMC10820346 DOI: 10.3390/v16010054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 12/19/2023] [Accepted: 12/22/2023] [Indexed: 01/24/2024] Open
Abstract
Japanese encephalitis virus is a mosquito-borne member of the Flaviviridae family. JEV is the leading cause of viral encephalitis in Asia and is characterized by encephalitis, high lethality, and neurological sequelae in survivors. The virus also causes severe disease in swine, which are an amplifying host in the transmission cycle, and in horses. US agricultural authorities have recently recognized the threat to the swine industry and initiated preparedness activities. Other mosquito-borne viruses exotic to the Western Hemisphere have been introduced and established in recent years, including West Nile, Zika, and chikungunya viruses, and JEV has recently invaded continental Australia for the first time. These events amply illustrate the potential threat of JEV to US health security. Susceptible indigenous mosquito vectors, birds, feral and domestic pigs, and possibly bats, constitute the receptive ecological ingredients for the spread of JEV in the US. Fortunately, unlike the other virus invaders mentioned above, an inactivated whole virus JE vaccine (IXIARO®) has been approved by the US Food and Drug Administration for human use in advance of a public health emergency, but there is no veterinary vaccine. This paper describes the risks and potential consequences of the introduction of JEV into the US, the need to integrate planning for such an event in public health policy, and the requirement for additional countermeasures, including antiviral drugs and an improved single dose vaccine that elicits durable immunity in both humans and livestock.
Collapse
Affiliation(s)
- Thomas P Monath
- Quigley BioPharma LLC, 114 Water Tower Plaza No. 1042, Leominster, MA 01453, USA
| |
Collapse
|
6
|
Ceconi M, Ariën KK, Delputte P. Diagnosing arthropod-borne flaviviruses: non-structural protein 1 (NS1) as a biomarker. Trends Microbiol 2023:S0966-842X(23)00334-7. [PMID: 38135616 DOI: 10.1016/j.tim.2023.11.016] [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: 09/11/2023] [Revised: 11/29/2023] [Accepted: 11/30/2023] [Indexed: 12/24/2023]
Abstract
In recent decades, the presence of flaviviruses of concern for human health in Europe has drastically increased,exacerbated by the effects of climate change - which has allowed the vectors of these viruses to expand into new territories. Co-circulation of West Nile virus (WNV), Usutu virus (USUV), and tick-borne encephalitis virus (TBEV) represents a threat to the European continent, and this is further complicated by the difficulty of obtaining an early and discriminating diagnosis of infection. Moreover, the possibility of introducing non-endemic pathogens, such as Japanese encephalitis virus (JEV), further complicates accurate diagnosis. Current flavivirus diagnosis is based mainly on RT-PCR and detection of virus-specific antibodies. Yet, both techniques suffer from limitations, and the development of new assays that can provide an early, rapid, low-cost, and discriminating diagnosis of viral infection is warranted. In the pursuit of ideal diagnostic assays, flavivirus non-structural protein 1 (NS1) serves as an excellent target for developing diagnostic assays based on both the antigen itself and the antibodies produced against it. This review describes the potential of such NS1-based diagnostic methods, focusing on the application of flaviviruses that co-circulate in Europe.
Collapse
Affiliation(s)
- Martina Ceconi
- Laboratory for Microbiology, Parasitology and Hygiene, Infla-Med Centre of Excellence, University of Antwerp, Antwerp 2610, Belgium
| | - Kevin K Ariën
- Virology Unit, Department of Biomedical Sciences, Institute of Tropical Medicine, Antwerp 2000, Belgium; Department of Biomedical Sciences, University of Antwerp, Antwerp 2610, Belgium
| | - Peter Delputte
- Laboratory for Microbiology, Parasitology and Hygiene, Infla-Med Centre of Excellence, University of Antwerp, Antwerp 2610, Belgium.
| |
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
Zhang W, Yin Q, Wang H, Liang G. The reemerging and outbreak of genotypes 4 and 5 of Japanese encephalitis virus. Front Cell Infect Microbiol 2023; 13:1292693. [PMID: 38076463 PMCID: PMC10698470 DOI: 10.3389/fcimb.2023.1292693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 10/31/2023] [Indexed: 12/18/2023] Open
Abstract
The Japanese encephalitis virus (JEV) is classified into five distinct genotypes, with genotypes 1 and 3 historically showing higher activity. These genotypes are the primary agents of viral encephalitis in the Asian continent. Genotypes 4 and 5 have remained silent in low-latitude tropical regions since their discovery. From 2009, the hidden genotype 5 suddenly emerged simultaneously in mosquitoes from the Tibetan region of China and those from South Korea in East Asia. The detection of genotype 5 of JEV in these mosquitoes was associated with cases of viral encephalitis in the local population. Similarly, in 2022, the long-silent genotype 4 of JEV emerged in Australia, resulting in a local outbreak of viral encephalitis that primarily affected adults and caused fatalities. The emergence and outbreaks of genotypes 4 and 5 of JEV present new challenges for the prevention and control of Japanese encephalitis (JE). This study not only analyzes the recent emergence of these new genotypes but also discusses their implications in the development of JE vaccines and laboratory tests for newly emerging JEV infections.
Collapse
Affiliation(s)
| | | | - Huanyu Wang
- Department of Arbovirus, National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Guodong Liang
- Department of Arbovirus, National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| |
Collapse
|
9
|
Periferakis A, Periferakis AT, Troumpata L, Periferakis K, Scheau AE, Savulescu-Fiedler I, Caruntu A, Badarau IA, Caruntu C, Scheau C. Kaempferol: A Review of Current Evidence of Its Antiviral Potential. Int J Mol Sci 2023; 24:16299. [PMID: 38003488 PMCID: PMC10671393 DOI: 10.3390/ijms242216299] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/07/2023] [Accepted: 11/12/2023] [Indexed: 11/26/2023] Open
Abstract
Kaempferol and its derivatives are flavonoids found in various plants, and a considerable number of these have been used in various medical applications worldwide. Kaempferol and its compounds have well-known antioxidant, anti-inflammatory and antimicrobial properties among other health benefits. However, the antiviral properties of kaempferol are notable, and there is a significant number of experimental studies on this topic. Kaempferol compounds were effective against DNA viruses such as hepatitis B virus, viruses of the alphaherpesvirinae family, African swine fever virus, and pseudorabies virus; they were also effective against RNA viruses, namely feline SARS coronavirus, dengue fever virus, Japanese encephalitis virus, influenza virus, enterovirus 71, poliovirus, respiratory syncytial virus, human immunodeficiency virus, calicivirus, and chikungunya virus. On the other hand, no effectiveness against murine norovirus and hepatitis A virus could be determined. The antiviral action mechanisms of kaempferol compounds are various, such as the inhibition of viral polymerases and of viral attachment and entry into host cells. Future research should be focused on further elucidating the antiviral properties of kaempferol compounds from different plants and assessing their potential use to complement the action of antiviral drugs.
Collapse
Affiliation(s)
- Argyrios Periferakis
- Department of Physiology, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
- Akadimia of Ancient Greek and Traditional Chinese Medicine, 16675 Athens, Greece
- Elkyda, Research & Education Centre of Charismatheia, 17675 Athens, Greece
| | - Aristodemos-Theodoros Periferakis
- Department of Physiology, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
- Elkyda, Research & Education Centre of Charismatheia, 17675 Athens, Greece
| | - Lamprini Troumpata
- Department of Physiology, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
| | - Konstantinos Periferakis
- Akadimia of Ancient Greek and Traditional Chinese Medicine, 16675 Athens, Greece
- Pan-Hellenic Organization of Educational Programs (P.O.E.P), 17236 Athens, Greece
| | - Andreea-Elena Scheau
- Department of Radiology and Medical Imaging, Fundeni Clinical Institute, 022328 Bucharest, Romania
| | - Ilinca Savulescu-Fiedler
- Department of Internal Medicine, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
- Department of Internal Medicine and Cardiology, Coltea Clinical Hospital, 030167 Bucharest, Romania
| | - Ana Caruntu
- Department of Oral and Maxillofacial Surgery, “Carol Davila” Central Military Emergency Hospital, 010825 Bucharest, Romania
- Department of Oral and Maxillofacial Surgery, Faculty of Dental Medicine, “Titu Maiorescu” University, 031593 Bucharest, Romania
| | - Ioana Anca Badarau
- Department of Physiology, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
| | - Constantin Caruntu
- Department of Physiology, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
- Department of Dermatology, “Prof. N.C. Paulescu” National Institute of Diabetes, Nutrition and Metabolic Diseases, 011233 Bucharest, Romania
| | - Cristian Scheau
- Department of Physiology, The “Carol Davila” University of Medicine and Pharmacy, 050474 Bucharest, Romania
- Department of Radiology and Medical Imaging, “Foisor” Clinical Hospital of Orthopaedics, Traumatology and Osteoarticular TB, 021382 Bucharest, Romania
| |
Collapse
|
10
|
Van den Eynde C, Sohier C, Matthijs S, De Regge N. Belgian Anopheles plumbeus Mosquitoes Are Competent for Japanese Encephalitis Virus and Readily Feed on Pigs, Suggesting a High Vectorial Capacity. Microorganisms 2023; 11:1386. [PMID: 37374888 DOI: 10.3390/microorganisms11061386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/15/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023] Open
Abstract
Anopheles plumbeus, a day-active mosquito known to feed aggressively on humans, was reported as a nuisance species near an abandoned pigsty in Belgium. Since Japanese encephalitis virus (JEV) is an emerging zoonotic flavivirus which uses pigs as amplification hosts, we investigated (1) whether An. plumbeus would feed on pigs and (2) its vector competence for JEV, to investigate whether this species could be a potential vector. Three- to seven-day-old F0-generation adult mosquitoes, emerged from field-collected larvae, were fed on a JEV genotype 3 Nakayama strain spiked blood meal. Blood-fed mosquitoes were subsequently incubated for 14 days at two temperature conditions: a constant 25 °C and a 25/15 °C day/night temperature gradient. Our results show that An. plumbeus is a competent vector for JEV at the 25 °C condition and this with an infection rate of 34.1%, a dissemination rate of 67.7% and a transmission rate of 14.3%. The vector competence showed to be influenced by temperature, with a significantly lower dissemination rate (16.7%) and no transmission when implementing the temperature gradient. Moreover, we demonstrated that An. plumbeus readily feeds on pigs when the opportunity occurs. Therefore, our results suggest that Belgian An. plumbeus mosquitoes may play an important role in the transmission of JEV upon an introduction into our region if temperatures increase with climate change.
Collapse
Affiliation(s)
- Claudia Van den Eynde
- Exotic and Vector-Borne Diseases, Sciensano, Groeselenberg 99, 1180 Brussels, Belgium
| | - Charlotte Sohier
- Exotic and Vector-Borne Diseases, Sciensano, Groeselenberg 99, 1180 Brussels, Belgium
| | - Severine Matthijs
- Viral Re-Emerging Enzootic and Bee Diseases, Sciensano, Groeselenberg 99, 1180 Brussels, Belgium
| | - Nick De Regge
- Exotic and Vector-Borne Diseases, Sciensano, Groeselenberg 99, 1180 Brussels, Belgium
| |
Collapse
|
11
|
Frank JC, Song BH, Lee YM. Mice as an Animal Model for Japanese Encephalitis Virus Research: Mouse Susceptibility, Infection Route, and Viral Pathogenesis. Pathogens 2023; 12:pathogens12050715. [PMID: 37242385 DOI: 10.3390/pathogens12050715] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Revised: 05/09/2023] [Accepted: 05/09/2023] [Indexed: 05/28/2023] Open
Abstract
Japanese encephalitis virus (JEV), a zoonotic flavivirus, is principally transmitted by hematophagous mosquitoes, continually between susceptible animals and incidentally from those animals to humans. For almost a century since its discovery, JEV was geographically confined to the Asia-Pacific region with recurrent sizable outbreaks involving wildlife, livestock, and people. However, over the past decade, it has been detected for the first time in Europe (Italy) and Africa (Angola) but has yet to cause any recognizable outbreaks in humans. JEV infection leads to a broad spectrum of clinical outcomes, ranging from asymptomatic conditions to self-limiting febrile illnesses to life-threatening neurological complications, particularly Japanese encephalitis (JE). No clinically proven antiviral drugs are available to treat the development and progression of JE. There are, however, several live and killed vaccines that have been commercialized to prevent the infection and transmission of JEV, yet this virus remains the main cause of acute encephalitis syndrome with high morbidity and mortality among children in the endemic regions. Therefore, significant research efforts have been directed toward understanding the neuropathogenesis of JE to facilitate the development of effective treatments for the disease. Thus far, multiple laboratory animal models have been established for the study of JEV infection. In this review, we focus on mice, the most extensively used animal model for JEV research, and summarize the major findings on mouse susceptibility, infection route, and viral pathogenesis reported in the past and present, and discuss some unanswered key questions for future studies.
Collapse
Affiliation(s)
- Jordan C Frank
- Department of Animal, Dairy, and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA
| | - Byung-Hak Song
- Department of Animal, Dairy, and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA
| | - Young-Min Lee
- Department of Animal, Dairy, and Veterinary Sciences, College of Agriculture and Applied Sciences, Utah State University, Logan, UT 84322, USA
| |
Collapse
|
12
|
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.
Collapse
|
13
|
Tong Y, Jiang H, Xu N, Wang Z, Xiong Y, Yin J, Huang J, Chen Y, Jiang Q, Zhou Y. Global Distribution of Culex tritaeniorhynchus and Impact Factors. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:4701. [PMID: 36981610 PMCID: PMC10048298 DOI: 10.3390/ijerph20064701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/04/2023] [Accepted: 03/06/2023] [Indexed: 06/18/2023]
Abstract
Culex tritaeniorhynchus is the primary vector of Japanese encephalitis (JE) and has a wide global distribution. However, the current and future geographic distribution maps of Cx. tritaeniorhynchus in global are still incomplete. Our study aims to predict the potential distribution of Cx. tritaeniorhynchus in current and future conditions to provide a guideline for the formation and implementation of vector control strategies all over the world. We collected and screened the information on the occurrence of Cx. tritaeniorhynchus by searching the literature and online databases and used ten algorithms to investigate its global distribution and impact factors. Cx. tritaeniorhynchus had been detected in 41 countries from 5 continents. The final ensemble model (TSS = 0.864 and AUC = 0.982) indicated that human footprint was the most important factor for the occurrence of Cx. tritaeniorhynchus. The tropics and subtropics, including southeastern Asia, Central Africa, southeastern North America and eastern South America, showed high habitat suitability for Cx. tritaeniorhynchus. Cx. tritaeniorhynchus is predicted to have a wider distribution in all the continents, especially in Western Europe and South America in the future under two extreme emission scenarios (SSP5-8.5 and SSP1-2.6). Targeted strategies for the control and prevention of Cx. tritaeniorhynchus should be further strengthened.
Collapse
Affiliation(s)
- Yixin Tong
- School of Public Health, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Center for Tropical Disease Research, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
| | - Honglin Jiang
- School of Public Health, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Center for Tropical Disease Research, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
| | - Ning Xu
- School of Public Health, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Center for Tropical Disease Research, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
| | - Zhengzhong Wang
- School of Public Health, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Center for Tropical Disease Research, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
| | - Ying Xiong
- School of Public Health, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Center for Tropical Disease Research, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
| | - Jiangfan Yin
- School of Public Health, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Center for Tropical Disease Research, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
| | - Junhui Huang
- School of Public Health, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Center for Tropical Disease Research, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
| | - Yue Chen
- School of Epidemiology and Public Health, Faculty of Medicine, University of Ottawa, 600 Peter Morand Crescent, Ottawa, ON K1G 5Z3, Canada
| | - Qingwu Jiang
- School of Public Health, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Center for Tropical Disease Research, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
| | - Yibiao Zhou
- School of Public Health, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Key Laboratory of Public Health Safety, Fudan University, Ministry of Education, Building 8, 130 Dong’an Road, Shanghai 200032, China
- Center for Tropical Disease Research, Fudan University, Building 8, 130 Dong’an Road, Shanghai 200032, China
| |
Collapse
|
14
|
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.
Collapse
|
15
|
Contrasting the Practices of Virus Isolation and Characterization between the Early Period in History and Modern Times: The Case of Japanese Encephalitis Virus. Viruses 2022; 14:v14122640. [PMID: 36560644 PMCID: PMC9781737 DOI: 10.3390/v14122640] [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: 10/10/2022] [Revised: 11/18/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022] Open
Abstract
Japanese encephalitis is a serious disease transmitted by mosquitoes. With its recent spread beyond the traditional territory of endemicity in Asia, the magnitude of global threat has increased sharply. While much of the current research are largely focused on changing epidemiology, molecular genetics of virus, and vaccination, little attention has been paid to the early history of virus isolation and phenotypic characterization of this virus. In this review, using this piece of history as an example, I review the transition of the concept and practice of virus isolation and characterization from the early period of history to modern times. The spectacular development of molecular techniques in modern times has brought many changes in practices as well as enormous amount of new knowledge. However, many aspects of virus characterization, in particular, transmission mechanism and host relationship, remain unsolved. As molecular techniques are not perfect in all respects, beneficial accommodation of molecular and biologic data is critically important in many branches of research. Accordingly, I emphasize exercising caution in applying only these modern techniques, point out unrecognized communication problems, and stress that JE research history is a rich source of interesting works still valuable even today and waiting to be discovered.
Collapse
|
16
|
Sikazwe C, Neave MJ, Michie A, Mileto P, Wang J, Cooper N, Levy A, Imrie A, Baird RW, Currie BJ, Speers D, Mackenzie JS, Smith DW, Williams DT. Molecular detection and characterisation of the first Japanese encephalitis virus belonging to genotype IV acquired in Australia. PLoS Negl Trop Dis 2022; 16:e0010754. [PMID: 36409739 PMCID: PMC9721490 DOI: 10.1371/journal.pntd.0010754] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 12/05/2022] [Accepted: 10/24/2022] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND A fatal case of Japanese encephalitis (JE) occurred in a resident of the Tiwi Islands, in the Northern Territory of Australia in February 2021, preceding the large JE outbreak in south-eastern Australia in 2022. This study reports the detection, whole genome sequencing and analysis of the virus responsible (designated JEV/Australia/NT_Tiwi Islands/2021). METHODS Reverse transcription quantitative PCR (RT-qPCR) testing was performed on post-mortem brain specimens using a range of JE virus (JEV)-specific assays. Virus isolation from brain specimens was attempted by inoculation of mosquito and mammalian cells or embryonated chicken eggs. Whole genome sequencing was undertaken using a combination of Illumina next generation sequencing methodologies, including a tiling amplicon approach. Phylogenetic and selection analyses were performed using alignments of the Tiwi Islands JEV genome and envelope (E) protein gene sequences and publicly available JEV sequences. RESULTS Virus isolation was unsuccessful and JEV RNA was detected only by RT-qPCR assays capable of detecting all JEV genotypes. Phylogenetic analysis revealed that the Tiwi Islands strain is a divergent member of genotype IV (GIV) and is closely related to the 2022 Australian outbreak virus (99.8% nucleotide identity). The Australian strains share highest levels of nucleotide identity with Indonesian viruses from 2017 and 2019 (96.7-96.8%). The most recent common ancestor of this Australian-Indonesian clade was estimated to have emerged in 2007 (95% HPD range: 1998-2014). Positive selection was detected using two methods (MEME and FEL) at several sites in the E and non-structural protein genes, including a single site in the E protein (S194N) unique to the Australian GIV strains. CONCLUSION This case represents the first detection of GIV JEV acquired in Australia, and only the second confirmed fatal human infection with a GIV JEV strain. The close phylogenetic relationship between the Tiwi Islands strain and recent Indonesian viruses is indicative of the origin of this novel GIV lineage, which we estimate has circulated in the region for several years prior to the Tiwi Islands case.
Collapse
Affiliation(s)
- Chisha Sikazwe
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
| | - Matthew J. Neave
- CSIRO Australian Centre for Disease Preparedness, Geelong, Victoria, Australia
| | - Alice Michie
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
| | - Patrick Mileto
- CSIRO Australian Centre for Disease Preparedness, Geelong, Victoria, Australia
| | - Jianning Wang
- CSIRO Australian Centre for Disease Preparedness, Geelong, Victoria, Australia
| | - Natalie Cooper
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
| | - Avram Levy
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
- School of Biomedical Sciences, University of Western Australia, Nedlands, Western Australia, Australia
| | - Allison Imrie
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
- School of Biomedical Sciences, University of Western Australia, Nedlands, Western Australia, Australia
| | - Robert W. Baird
- Pathology and Infectious Diseases Departments, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Bart J. Currie
- Pathology and Infectious Diseases Departments, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - David Speers
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
| | - John S. Mackenzie
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
- Faculty of Health Sciences, Curtin University, Bentley, Western Australia, Australia
| | - David W. Smith
- PathWest Laboratory Medicine Western Australia, Nedlands, Western Australia, Australia
- * E-mail: (DWS); (DTW)
| | - David T. Williams
- CSIRO Australian Centre for Disease Preparedness, Geelong, Victoria, Australia
- * E-mail: (DWS); (DTW)
| |
Collapse
|
17
|
Japanese Encephalitis Virus: The Emergence of Genotype IV in Australia and Its Potential Endemicity. Viruses 2022; 14:v14112480. [PMID: 36366578 PMCID: PMC9698845 DOI: 10.3390/v14112480] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 11/04/2022] [Accepted: 11/07/2022] [Indexed: 11/11/2022] Open
Abstract
A fatal case of Japanese encephalitis (JE) occurred in northern Australia in early 2021. Sequence studies showed that the virus belonged to genotype IV (GIV), a genotype previously believed to be restricted to the Indonesian archipelago. This was the first locally acquired case of Japanese encephalitis virus (JEV) GIV to occur outside Indonesia, and the second confirmed fatal human case caused by a GIV virus. A closely related GIV JEV strain subsequently caused a widespread outbreak in eastern Australia in 2022 that was first detected by fetal death and abnormalities in commercial piggeries. Forty-two human cases also occurred with seven fatalities. This has been the first major outbreak of JEV in mainland Australia, and geographically the largest virgin soil outbreak recorded for JEV. This outbreak provides an opportunity to discuss and document the factors involved in the virus' spread and its ecology in a novel ecological milieu in which other flaviviruses, including members of the JE serological complex, also occur. The probable vertebrate hosts and mosquito vectors are discussed with respect to virus spread and its possible endemicity in Australia, and the need to develop a One Health approach to develop improved surveillance methods to rapidly detect future outbreak activity across a large geographical area containing a sparse human population. Understanding the spread of JEV in a novel ecological environment is relevant to the possible threat that JEV may pose in the future to other receptive geographic areas, such as the west coast of the United States, southern Europe or Africa.
Collapse
|
18
|
Hernández-Triana LM, Folly AJ, Sewgobind S, Lean FZX, Ackroyd S, Nuñez A, Delacour S, Drago A, Visentin P, Mansfield KL, Johnson N. Susceptibility of Aedes albopictus and Culex quinquefasciatus to Japanese encephalitis virus. Parasit Vectors 2022; 15:210. [PMID: 35710580 PMCID: PMC9204976 DOI: 10.1186/s13071-022-05329-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 05/19/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Japanese encephalitis virus (JEV) is the principal cause of mosquito-borne encephalitis in human populations within Asia. If introduced into new geographic areas, it could have further implications for public and animal health. However, potential mosquito vectors for virus transmission have not been fully investigated. The Asian tiger mosquito, Aedes albopictus, has emerged in Europe and is now expanding its geographical range into more northerly latitudes. Culex quinquefasciatus, although absent from Europe, has been detected in Turkey, a country with territory in Europe, and could act as a vector for JEV in other regions. To assess the risk of these invasive species acting as vectors for JEV and therefore potentially contributing to its geographical expansion, we have investigated the vector competence of Ae. albopictus and Cx. quinquefasciatus. METHODS Two colonised lines of Ae. albopictus (Italy and Spain) and a line of Cx. quinquefasciatus (Tanzania) were compared for susceptibility to infection by oral feeding with JEV strain SA-14, genotype III at 106 PFU/ml and maintained at 25 °C. Specimens were processed at 7 and 14 days post-inoculation (dpi). Rates of infection, dissemination and transmission were assessed through detection of viral RNA by real-time polymerase chain reaction (RT-PCR) in mosquito body, legs and saliva, respectively, at each time point. Where possible, infection and dissemination were confirmed by immunohistochemical (IHC) detection of the JEV envelope protein. RESULTS Aedes albopictus from Italy showed no susceptibility to infection with JEV strain SA-14. Conversely, Ae. albopictus colonised in Spain was susceptible and 100% of infected mosquitoes that were subjected to saliva screening expressed viral RNA at 14 dpi. Culex quinquefasciatus was highly susceptible to infection as early as 7 dpi and 50% of infected mosquitoes that were subjected to saliva screening expressed viral RNA at 14 dpi. Infection and dissemination were confirmed in Cx. quinquefasciatus by IHC detection of JEV envelope protein in both the mid-gut and salivary glands. CONCLUSIONS Aedes albopictus from two different locations in Europe range from being susceptible to JEV and capable of transmission through to being resistant. Culex quinquefasciatus also appears highly susceptible; therefore, both species could potentially act as vectors for JEV and facilitate the emergence of JEV into new regions.
Collapse
Affiliation(s)
| | - Arran J Folly
- Vector Borne Diseases, Animal and Plant Health Agency, Addlestone, Surrey, UK
| | - Sanam Sewgobind
- Vector Borne Diseases, Animal and Plant Health Agency, Addlestone, Surrey, UK
| | - Fabian Z X Lean
- Pathology and Animal Sciences Department, Animal and Plant Health Agency, Addlestone, Surrey, UK
| | - Stuart Ackroyd
- Pathology and Animal Sciences Department, Animal and Plant Health Agency, Addlestone, Surrey, UK
| | - Alejandro Nuñez
- Pathology and Animal Sciences Department, Animal and Plant Health Agency, Addlestone, Surrey, UK
| | - Sarah Delacour
- Veterinary Faculty, University of Zaragoza, Zaragoza, Spain
| | - Andrea Drago
- Entostudio SrL, Viale del Lavoro 66, Ponte San Nicolò, Padua, Italy
| | | | - Karen L Mansfield
- Vector Borne Diseases, Animal and Plant Health Agency, Addlestone, Surrey, UK
| | - Nicholas Johnson
- Vector Borne Diseases, Animal and Plant Health Agency, Addlestone, Surrey, UK
| |
Collapse
|
19
|
Putra IGAA, Adi AAAM, Astawa INM, Kardena IM, Wandia IN, Soma IG, Brotcorne F, Fuentes A. First survey on seroprevalence of Japanese encephalitis in long-tailed macaques (Macaca fascicularis) in Bali, Indonesia. Vet World 2022; 15:1341-1346. [PMID: 35765485 PMCID: PMC9210850 DOI: 10.14202/vetworld.2022.1341-1346] [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: 01/17/2022] [Accepted: 04/18/2022] [Indexed: 01/20/2023] Open
Abstract
Background and Aim: Japanese encephalitis (JE) is a zoonotic infectious inflammatory brain disease caused by the JE virus (JEV). Considerable research into the seroprevalence of JE in domestic animals has been conducted, but there have been no reports of its occurrence in wild animals, including long-tailed macaques (Macaca fascicularis). This study aimed to estimate the seroprevalence of JEV infection and its determinants in long-tailed macaques in Bali and the prevalence of mosquito vectors. Materials and Methods: Blood samples (3 mL) were collected from a population of M. fascicularis (92 heads) inhabiting a small forest with irrigated rice field nearby (wetland area) in Ubud, Gianyar, and from two populations in dryland areas with no wet rice field (Uluwatu, Badung, and Nusa Penida, Bali Province, Indonesia). The collected sera were tested for antibodies against JEV using a commercially available enzyme-linked immunosorbent assay kit (qualitative monkey JE Immunoglobulin G antibody kit). The seropositivity of the antibodies was then compared based on different variables, namely, habitat type, age, and sex. Results: The seroprevalence of the JEV antibodies in all the samples tested was found to be 41.3%. The seropositivity of the monkey serum samples collected from the wetland area was 46.4%, which was higher than the seropositivity of the sera samples collected from the dried field areas (1.25%). Monkey sera collected from the wetland areas were 6.1 times (odds ratio [OR]: 6.1; 95% confidence interval [CI]: 0.71-51.5, p>0.05) more likely to be seropositive compared to the monkey sera collected from the dried field areas. Meanwhile, female monkeys were 1.79 times (OR: 1.79; 95% CI: 0.76-4.21; p>0.05) more likely to be seropositive to JEV than males. Similarly, juvenile monkeys were 2.38 times (OR: 2.38; 95% CI: 0.98-5.79); p>0.05) more likely to be seropositive against the JEV than adult monkeys. However, none of these differences achieved statistical significance. Regarding the JEV mosquito vector collection, more Culex mosquitoes were found in the samples from the wetland areas than from the dried field areas. Conclusion: The study confirms the existence of JEV infection in long-tailed macaques in Bali. There were patterned seropositivity differences based on habitat, age, and sex of the monkeys, but these were not significant. The possibility of monkeys as a JEV reservoir and the presence of the mosquitoes as the JEV vector are suggested but require more study to confirm.
Collapse
Affiliation(s)
- I Gusti Agung Arta Putra
- Laboratory of Animal Anatomy and Physiology, Faculty of Animal Husbandry, Udayana University, Kampus Bukit, Jimbaran, Badung, Bali, Indonesia; Primate Research Center, Udayana University, Kampus Bukit, Jimbaran, Badung, Bali, Indonesia
| | - Anak Agung Ayu Mirah Adi
- Laboratory of Veterinary Pathology, Faculty of Veterinary Medicine, Udayana University, Kampus Sudirman, Jalan PB Sudirman, Denpasar, Bali, Indonesia
| | - I Nyoman Mantik Astawa
- Laboratory of Veterinary Virology, Faculty of Veterinary Medicine, Udayana University, Kampus Sudirman, Jalan PB Sudirman, Denpasar, Bali, Indonesia
| | - I Made Kardena
- Laboratory of Veterinary Pathology, Faculty of Veterinary Medicine, Udayana University, Kampus Sudirman, Jalan PB Sudirman, Denpasar, Bali, Indonesia
| | - I Nengah Wandia
- Primate Research Center, Udayana University, Kampus Bukit, Jimbaran, Badung, Bali, Indonesia
| | - I Gede Soma
- Primate Research Center, Udayana University, Kampus Bukit, Jimbaran, Badung, Bali, Indonesia
| | - Fany Brotcorne
- Research Unit SPHERES, Department of Biology, Ecology, and Evolution, University of Liege, Belgium
| | - Agustin Fuentes
- Department of Anthropology, Princeton University, 123 Aaron Burr Hall, Princeton NJ 08544, United States
| |
Collapse
|
20
|
Pham-Thanh L, Nguyen-Tien T, Magnusson U, Bui VN, Bui AN, Lundkvist Å, Vu DT, Tran SH, Can MX, Nguyen-Viet H, Lindahl JF. Zoonotic Flavivirus Exposure in Peri-Urban and Suburban Pig-Keeping in Hanoi, Vietnam, and the Knowledge and Preventive Practices of Pig Farmers. Trop Med Infect Dis 2022; 7:tropicalmed7050079. [PMID: 35622706 PMCID: PMC9143339 DOI: 10.3390/tropicalmed7050079] [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] [Received: 04/07/2022] [Revised: 04/27/2022] [Accepted: 05/17/2022] [Indexed: 02/01/2023] Open
Abstract
Mosquito-borne diseases (MBDs), including those caused by flaviviruses, remain human health problems for developing and urbanizing economies. This cross-sectional study examined risks of flavivirus exposure through a survey regarding knowledge and practices of pig farmers, and serological analysis of pigs in peri-urban and suburban Hanoi city. A total of 636 pig sera from 179 pig farms in 4 districts, namely, Chuong My, Dan Phuong, Ha Dong, and Bac Tu Liem, were analyzed by a competitive ELISA designed for flavivirus antibody detection. The results indicated a low level of awareness about MBDs among pig farmers, and a high seroprevalence in pigs at 88.5% (95%CI = 85.8–90.9%). Moreover, common practices of pig owners to prevent mosquitoes at home and farm did not show a significant reduction in flavivirus exposure in pigs. At animal level, significant associations between seropositive pigs and the farms with more than 60 pigs, and the district location were found. Farm-level multivariable analysis did not identify significant risk factors for flavivirus exposure. The study suggests that improving awareness of pig owners about MBDs in Hanoi city may be warranted to reduce the risk for MBD flavivirus infections in both humans and pigs.
Collapse
Affiliation(s)
- Long Pham-Thanh
- International Livestock Research Institute (ILRI), Hanoi 10000, Vietnam; (T.N.-T.); (H.N.-V.); (J.F.L.)
- Department of Medical Biochemistry and Microbiology, Uppsala University, 75123 Uppsala, Sweden;
- Department of Animal Health, Ministry of Agriculture and Rural Development, Hanoi 10000, Vietnam
- Correspondence: ; Tel.: +84-934-109-999
| | - Thang Nguyen-Tien
- International Livestock Research Institute (ILRI), Hanoi 10000, Vietnam; (T.N.-T.); (H.N.-V.); (J.F.L.)
- Department of Medical Biochemistry and Microbiology, Uppsala University, 75123 Uppsala, Sweden;
| | - Ulf Magnusson
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, 75123 Uppsala, Sweden;
| | - Vuong Nghia Bui
- National Institute for Veterinary Research, Hanoi 10000, Vietnam; (V.N.B.); (A.N.B.)
| | - Anh Ngoc Bui
- National Institute for Veterinary Research, Hanoi 10000, Vietnam; (V.N.B.); (A.N.B.)
| | - Åke Lundkvist
- Department of Medical Biochemistry and Microbiology, Uppsala University, 75123 Uppsala, Sweden;
| | - Duoc Trong Vu
- National Institute for Hygiene and Epidemiology, Hanoi 10000, Vietnam; (D.T.V.); (S.H.T.)
| | - Son Hai Tran
- National Institute for Hygiene and Epidemiology, Hanoi 10000, Vietnam; (D.T.V.); (S.H.T.)
| | - Minh Xuan Can
- Hanoi Sub-Department of Livestock Production and Animal Health, Hanoi 10000, Vietnam;
| | - Hung Nguyen-Viet
- International Livestock Research Institute (ILRI), Hanoi 10000, Vietnam; (T.N.-T.); (H.N.-V.); (J.F.L.)
| | - Johanna F. Lindahl
- International Livestock Research Institute (ILRI), Hanoi 10000, Vietnam; (T.N.-T.); (H.N.-V.); (J.F.L.)
- Department of Medical Biochemistry and Microbiology, Uppsala University, 75123 Uppsala, Sweden;
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, 75123 Uppsala, Sweden;
| |
Collapse
|
21
|
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.
Collapse
|
22
|
Xu C, Zhang W, Pan Y, Wang G, Yin Q, Fu S, Li F, He Y, Xu S, Wang Z, Liang G, Nie K, Wang H. A Bibliometric Analysis of Global Research on Japanese Encephalitis From 1934 to 2020. Front Cell Infect Microbiol 2022; 12:833701. [PMID: 35155284 PMCID: PMC8829047 DOI: 10.3389/fcimb.2022.833701] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 01/04/2022] [Indexed: 12/13/2022] Open
Abstract
Japanese encephalitis (JE) is a mosquito-borne disease caused by the Japanese encephalitis virus (JEV). The disease is mainly an epidemic in Asia and has been studied for nearly 90 years. To evaluate the research trends of JE, 3,023 English publications between 1934 and 2020 were retrieved and analyzed from the Web of Science database using indicators for publication, country or territory, citation, journal, author and affiliation, keyword co-occurrence cluster, and strongest citation bursts detection. The results of the bibliometric analysis and the visualization tools show that the number of annual publications on JE has been increasing. JE has been continuously studied in the USA and also many Asian countries, such as Japan, China, India, and South Korea; however, only a few publications have high citations. The main research groups of JE in the last 5 years were in China, Japan, and the UK. The keyword co-occurrence analysis and the strongest citation bursts detection revealed that most studies focused on the pathogenic mechanism of JEV, control of outbreaks, and immunization with JE vaccine. The research maps on JE obtained by our analysis are expected to help researchers effectively explore the disease.
Collapse
Affiliation(s)
- Chongxiao Xu
- Department of Arboviruses, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Weijia Zhang
- Department of Arboviruses, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Yuefeng Pan
- Saint John’s Preparatory School, Collegeville, MN, United States
| | - Guowei Wang
- School of Clinical Medicine, Ningxia Medical University, Yinchuan, China
| | - Qikai Yin
- Department of Arboviruses, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Shihong Fu
- Department of Arboviruses, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Fan Li
- Department of Arboviruses, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Ying He
- Department of Arboviruses, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Songtao Xu
- Department of Arboviruses, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Zhenhai Wang
- Department of Neurology, General Hospital of Ningxia Medical University, Engineering Research Center for Diagnosis and Treatment of Ningxia Nervous System Diseases, Yinchuan, China
| | - Guodong Liang
- Department of Arboviruses, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Kai Nie
- Department of Arboviruses, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China
- *Correspondence: Huanyu Wang, ; Kai Nie,
| | - Huanyu Wang
- Department of Arboviruses, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China
- Chinese Center for Disease Control and Prevention Wuhan Institute of Virology, Chinese Academy of Sciences Joint Research Center for Emerging Infectious Diseases and Biosafety, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, China
- *Correspondence: Huanyu Wang, ; Kai Nie,
| |
Collapse
|
23
|
Chiou SS, Chen JM, Chen YY, Chia MY, Fan YC. The feasibility of field collected pig oronasal secretions as specimens for the virologic surveillance of Japanese encephalitis virus. PLoS Negl Trop Dis 2021; 15:e0009977. [PMID: 34860839 PMCID: PMC8673640 DOI: 10.1371/journal.pntd.0009977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 12/15/2021] [Accepted: 11/05/2021] [Indexed: 11/24/2022] Open
Abstract
Virologic surveillance of Japanese encephalitis virus (JEV) relies on collecting pig blood specimens and adult mosquitoes in the past. Viral RNAs extracted from pig blood specimens suffer from low detecting positivity by reverse transcription PCR (RT-PCR). The oronasal transmission of the virus has been demonstrated in experimentally infected pigs. This observation suggested oronasal specimens could be useful source in the virus surveillance. However, the role of this unusual route of transmission remains unproven in the operational pig farm. In this study, we explore the feasibility of using pig oronasal secretions collected by chewing ropes to improve the positivity of detection in commercial pig farms. The multiplex genotype-specific RT-PCR was used in this study to determine and compare the positivity of detecting JEV viral RNAs in pig’s oronasal secretions and blood specimens, and the primary mosquito vector. Oronasal specimens had the overall positive rate of 6.0% (95% CI 1.3%–16.6%) (3/50) to 10.0% (95% CI 2.1%–26.5%) (3/30) for JEV during transmission period despite the negative results of all blood-derived specimens (n = 2442). Interestingly, pig oronasal secretions and female Culex tritaeniorhynchus mosquito samples collected from the same pig farm showed similar viral RNA positive rates, 10.0% (95% CI 2.1%–26.5%) (3/30) and 8.9% (95% CI 2.5%–21.2%) (4/45), respectively (p> 0.05). Pig oronasal secretion-based surveillance revealed the seasonality of viral activity and identified closely related genotype I virus derived from the mosquito isolates. This finding indicates oronasal secretion-based RT-PCR assay can be a non-invasive, alternative method of implementing JEV surveillance in the epidemic area prior to the circulation of virus-positive mosquitoes. Mosquito-borne Japanese encephalitis virus (JEV) has either endemic or seasonal patterns of transmission in Asia and Australia. Most hosts infected by the virus remains asymptomatic but can result in severe encephalitis in humans and horses, and abortion or stillbirth in pregnant sows. Isolation of virus in adult mosquitoes or pig seroconversion has been used as an early indicator of upcoming JE outbreak in humans. Genotype identification of the virus is important since current human and domestic animal vaccines are all genotype III (GIII) specific. GIII vaccine elicited immunity has reduced cross-protections to genotypes other than GIII. Our virologic surveillance using pig’s oronasal secretion detected higher prevalence and earlier genotype I virus activity than using pig’s blood and mosquitoes, respectively. This proposed surveillance tool might be more effective that will allow the public health agency to properly implement the preventive measures, such as implementing mosquito control, encouraging booster vaccination, and encouraging the use of mosquito repellent, to reduce the impact of upcoming outbreak. Collection of pig’s oronasal secretion is non-invasive to pigs and less technically demanding to operators. Thus we propose the use of pig’s oronasal secretions as the novel source of specimens for virologic surveillance to replace the traditional pig blood or adult mosquito specimens to monitor and control JE outbreak/epidemic in the future.
Collapse
Affiliation(s)
- Shyan-Song Chiou
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Jo-Mei Chen
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Yi-Ying Chen
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Min-Yuan Chia
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Yi-Chin Fan
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
- * E-mail:
| |
Collapse
|
24
|
Liu H, Zhang J, Niu Y, Liang G. The 5' and 3' Untranslated Regions of the Japanese Encephalitis Virus (JEV): Molecular Genetics and Higher Order Structures. Front Microbiol 2021; 12:730045. [PMID: 34777278 PMCID: PMC8581615 DOI: 10.3389/fmicb.2021.730045] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 09/22/2021] [Indexed: 11/22/2022] Open
Abstract
The untranslated region (UTRs) of viral genome are important for viral replication and immune modulation. Japanese encephalitis virus (JEV) is the most significant cause of epidemic encephalitis worldwide. However, little is known regarding the characterization of the JEV UTRs. Here, systematic analyses of the UTRs of JEVs isolated from a variety of hosts worldwide spanning about 80 years were made. All the important cis-acting elements and structures were compared with other mosquito-borne Flaviviruses [West Nile virus (WNV), Yellow fever virus (YFV), Zika virus (ZIKV), Dengue virus (DENV)] and annotated in detail in the UTRs of different JEV genotypes. Our findings identified the JEV-specific structure and the sequence motif with unique JEV feature. (i) The 3’ dbsHP was identified as a small hairpin located in the DB region in the 3′ UTR of JEV, with the structure highly conserved among the JEV genotypes. (ii) The spacer sequence UARs of JEV consist of four discrete spacer sequences, whereas the UARs of other mosquito-borne Flaviviruses are continuous sequences. In addition, repetitive elements have been discovered in the UTRs of mosquito-borne Flaviviruses. The lengths, locations, and numbers of the repetitive elements of JEV also differed from other Flaviviruses (WNV, YFV, ZIKV, DENV). A 300 nt-length region located at the beginning of the 3′ UTR exhibited significant genotypic specificity. This study lays the basis for future research on the relationships between the JEV specific structures and elements in the UTRs, and their important biological function.
Collapse
Affiliation(s)
- Hong Liu
- Shandong Provincial Research Center for Bioinformatic Engineering and Technique, School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China.,Zibo Key Laboratory of Precise Gene Detection, Zibo, China
| | - Jun Zhang
- Shandong Provincial Research Center for Bioinformatic Engineering and Technique, School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - Yuzhen Niu
- Shandong Provincial Research Center for Bioinformatic Engineering and Technique, School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - 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, China
| |
Collapse
|
25
|
Immunological Analysis of Nodavirus Capsid Displaying the Domain III of Japanese Encephalitis Virus Envelope Protein. Pharmaceutics 2021; 13:pharmaceutics13111826. [PMID: 34834244 PMCID: PMC8618745 DOI: 10.3390/pharmaceutics13111826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 10/13/2021] [Accepted: 10/17/2021] [Indexed: 11/29/2022] Open
Abstract
Japanese encephalitis virus (JEV) is the pathogen that causes Japanese encephalitis (JE) in humans and horses. Lethality of the virus was reported to be between 20–30%, of which, 30–50% of the JE survivors develop neurological and psychiatric sequelae. Attributed to the low effectiveness of current therapeutic approaches against JEV, vaccination remains the only effective approach to prevent the viral infection. Currently, live-attenuated and chimeric-live vaccines are widely used worldwide but these vaccines pose a risk of virulence restoration. Therefore, continuing development of JE vaccines with higher safety profiles and better protective efficacies is urgently needed. In this study, the Macrobrachium rosenbergii nodavirus (MrNV) capsid protein (CP) fused with the domain III of JEV envelope protein (JEV-DIII) was produced in Escherichia coli. The fusion protein (MrNV-CPJEV-DIII) assembled into virus-like particles (VLPs) with a diameter of approximately 18 nm. The BALB/c mice injected with the VLPs alone or in the presence of alum successfully elicited the production of anti-JEV-DIII antibody, with titers significantly higher than that in mice immunized with IMOJEV, a commercially available vaccine. Immunophenotyping showed that the MrNV-CPJEV-DIII supplemented with alum triggered proliferation of cytotoxic T-lymphocytes, macrophages, and natural killer (NK) cells. Additionally, cytokine profiles of the immunized mice revealed activities of cytotoxic T-lymphocytes, macrophages, and NK cells, indicating the activation of adaptive cellular and innate immune responses mediated by MrNV-CPJEV-DIII VLPs. Induction of innate, humoral, and cellular immune responses by the MrNV-CPJEV-DIII VLPs suggest that the chimeric protein is a promising JEV vaccine candidate.
Collapse
|
26
|
Xing J, Liang J, Liu S, Huang L, Hu P, Liu L, Liao M, Qi W. Japanese encephalitis virus restricts HMGB1 expression to maintain MAPK pathway activation for viral replication. Vet Microbiol 2021; 262:109237. [PMID: 34592637 DOI: 10.1016/j.vetmic.2021.109237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 09/11/2021] [Indexed: 12/17/2022]
Abstract
Japanese encephalitis virus (JEV) is a typical insect-borne flavivirus and an important zoonotic pathogen that causes human viral encephalitis and reproductive failure in pigs. Various strategies were utilized by JEV to facilitate its replication. It is important to identify key molecules that mediate JEV infection, as well as to investigate their underlying mechanism. In this study, the critical role of high-mobility group box 1 (HMGB1), a non-histone, DNA-binding protein, was assessed in JEV propagation. Upon JEV infection, the HMGB1 mRNA and protein levels were down-regulated at late infection in Huh7 cells. JEV replication was significantly enhanced with HMGB1 knock-down by siRNA and knock-out by the CRISPR/Cas9 system, whereas JEV growth was restricted in HMGB1-over-expressed Huh7 cells. Further investigation showed that HMGB1 suppressed MAPK pathway, and demonstrated that the weakening of MAPK pathway negatively regulated JEV infection. Together, these results suggested that JEV restricted HMGB1 expression to maintain MAPK pathway activation for viral replication. Our data showed that HMGB1 played a key role in JEV infection, providing the potential for the development of a novel drug to combat JEV infection.
Collapse
Affiliation(s)
- Jinchao Xing
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Zoonosis, Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China; Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Jiaqi Liang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Zoonosis, Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China; Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Shukai Liu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Lihong Huang
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong 999077, China
| | - Pingsheng Hu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Lele Liu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Zoonosis, Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China; Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Ming Liao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Zoonosis, Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China; Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou 510642, China.
| | - Wenbao Qi
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Zoonosis, Ministry of Agriculture and Rural Affairs, Guangzhou 510642, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China; National Engineering Research Center for Breeding Swine Industry, Guangzhou 510642, China; Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou 510642, China.
| |
Collapse
|
27
|
Park SL, Huang YJS, Lyons AC, Ayers VB, Hettenbach SM, McVey DS, Noronha LE, Burton KR, Hsu WW, Higgs S, Vanlandingham DL. Mosquito Saliva Modulates Japanese Encephalitis Virus Infection in Domestic Pigs. FRONTIERS IN VIROLOGY 2021. [DOI: 10.3389/fviro.2021.724016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that is the leading cause of pediatric viral encephalitis in Asia. Japanese encephalitis virus is transmitted by Culex species mosquitoes that also vector several zoonotic flaviviruses. Despite the knowledge that mosquito saliva contains molecules that may alter flavivirus pathogenesis, whether or not the deposition of viruses by infected mosquitoes has an impact on the kinetics and severity of JEV infection has not been thoroughly examined, especially in mammalian species involved in the enzootic transmission. Most JEV pathogenesis models were established using needle inoculation. Mouse models for West Nile (WNV) and dengue (DENV) viruses have shown that mosquito saliva can potentiate flavivirus infections and exacerbate disease symptoms. In this study, we determined the impact of mosquito salivary components on the pathogenesis of JEV in pigs, a species directly involved in its transmission cycle as an amplifying host. Interestingly, co-injection of JEV and salivary gland extract (SGE) collected from Culex quinquefasciatus produced milder febrile illness and shortened duration of nasal shedding but had no demonstrable impact on viremia and neuroinvasion. Our findings highlight that mosquito salivary components can differentially modulate the outcomes of flavivirus infections in amplifying hosts and in mouse models.
Collapse
|
28
|
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.
Collapse
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
| |
Collapse
|
29
|
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: 30] [Impact Index Per Article: 10.0] [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.
Collapse
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
| |
Collapse
|
30
|
Vannice KS, Hills SL, Schwartz LM, Barrett AD, Heffelfinger J, Hombach J, Letson GW, Solomon T, Marfin AA. The future of Japanese encephalitis vaccination: expert recommendations for achieving and maintaining optimal JE control. NPJ Vaccines 2021; 6:82. [PMID: 34131150 PMCID: PMC8206071 DOI: 10.1038/s41541-021-00338-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 04/15/2021] [Indexed: 02/05/2023] Open
Abstract
Vaccines against Japanese encephalitis (JE) have been available for decades. Currently, most JE-endemic countries have vaccination programs for their at-risk populations. Even so, JE remains the leading recognized cause of viral encephalitis in Asia. In 2018, the U.S. Centers for Disease Control and Prevention and PATH co-convened a group of independent experts to review JE prevention and control successes, identify remaining scientific and operational issues that need to be addressed, discuss opportunities to further strengthen JE vaccination programs, and identify strategies and solutions to ensure sustainability of JE control during the next decade. This paper summarizes the key discussion points and recommendations to sustain and expand JE control.
Collapse
Affiliation(s)
| | - Susan L Hills
- Arboviral Diseases Branch, Centers for Disease Control and Prevention, Fort Collins, CO, USA
| | | | - Alan D Barrett
- Sealy Institute for Vaccine Sciences, Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | | | - Joachim Hombach
- Department of Immunizations, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
| | | | - Tom Solomon
- National Institute for Health Research Health Protection Research Unit in Emerging and Zoonotic Infections, and Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
- Walton Centre NHS Foundation Trust, Liverpool, UK
| | | |
Collapse
|
31
|
Abdelkrim O, Samia B, Said Z, Souad L. Modeling and mapping the habitat suitability and the potential distribution of Arboviruses vectors in Morocco. Parasite 2021; 28:37. [PMID: 33861197 PMCID: PMC8051322 DOI: 10.1051/parasite/2021030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 03/13/2021] [Indexed: 12/14/2022] Open
Abstract
Mosquitoes transmit several agents of diseases and the presence of different species represents a threat to animal and public health. Aedes and Culex mosquitoes are of particular concern giving their potential vector competence for Arbovirus transmission. In Morocco, the lack of detailed information related to their spatial distribution raises major concerns and hampers effective vector surveillance and control. Using maximum entropy (Maxent) modeling, we generated prediction models for the potential distribution of Arboviruses vectors (Aedes aegypti, Ae. vexans, Ae. caspius, Ae. detritus, and Culex pipiens) in Morocco, under current climatic conditions. Also, we investigated the habitat suitability for the potential occurrence and establishment of Ae. albopictus and Ae. vittatus recorded only once in the country. Prediction models for these last two species were generated considering occurrence datasets from close countries of the Mediterranean Basin, where Ae. albopictus is well established, and from a worldwide database for the case of Ae. vittatus (model transferability). With the exception of Ae. vittatus, the results identify potential habitat suitability in Morocco for all mosquitos considered. Existing areas with maximum risk of establishment and high potential distribution were mainly located in the northwestern and central parts of Morocco. Our results essentially underline the assumption that Ae. albopictus, if not quickly controlled, might find suitable habitats and has the potential to become established, especially in the northwest of the country. These findings may help to better understand the potential distribution of each species and enhance surveillance efforts in areas identified as high risk.
Collapse
Affiliation(s)
- Outammassine Abdelkrim
-
Laboratory of Microbiology and Virology, Department of Medical Biology, Faculty of Medicine and Pharmacy, Cadi Ayyad University PO Box 7010 40000 Marrakech Morocco
| | - Boussaa Samia
-
ISPITS-Higher Institute of Nursing and Health Technology 40000 Marrakech Morocco
-
Ecology and the Environment Laboratory L2E (URAC 32, CNRST ERACNERS 06), Faculty of Sciences Semlalia, Cadi Ayyad University 2390-40080 Marrakech Morocco
| | - Zouhair Said
-
Laboratory of Microbiology and Virology, Department of Medical Biology, Faculty of Medicine and Pharmacy, Cadi Ayyad University PO Box 7010 40000 Marrakech Morocco
-
Laboratory of Bacteriology–Virology, Avicienne Hospital Military 40000 Marrakech Morocco
| | - Loqman Souad
-
Laboratory of Microbiology and Virology, Department of Medical Biology, Faculty of Medicine and Pharmacy, Cadi Ayyad University PO Box 7010 40000 Marrakech Morocco
| |
Collapse
|
32
|
Faizah AN, Kobayashi D, Amoa-Bosompem M, Higa Y, Tsuda Y, Itokawa K, Miura K, Hirayama K, Sawabe K, Isawa H. Evaluating the competence of the primary vector, Culex tritaeniorhynchus, and the invasive mosquito species, Aedes japonicus japonicus, in transmitting three Japanese encephalitis virus genotypes. PLoS Negl Trop Dis 2020; 14:e0008986. [PMID: 33370301 PMCID: PMC7793266 DOI: 10.1371/journal.pntd.0008986] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 01/08/2021] [Accepted: 11/12/2020] [Indexed: 01/13/2023] Open
Abstract
Japanese encephalitis virus (JEV) is maintained in an enzootic cycle between swine, water birds, and mosquitoes. JEV has circulated indigenously in Asia, with Culex tritaeniorhynchus as the primary vector. In some areas where the primary vector is scarce or absent, sporadic cases of Japanese encephalitis have been reported, with Aedes japonicus japonicus presumed to have the potential as a secondary vector. As one of the world's most invasive culicid species, Ae. j. japonicus carries a considerable health risk for spreading diseases to wider areas, including Europe and North America. Thus, evaluation of its competency as a JEV vector, particularly in a native population, will be essential in preventing potential disease spread. In this study, the two mosquito species' vector competence in transmitting three JEV genotypes (I, III, and V) was assessed, with Cx. tritaeniorhynchus serving as a point of reference. The mosquitoes were virus-fed and the infection rate (IR), dissemination rate (DR), and transmission rate (TR) evaluated individually by either RT-qPCR or focus forming assay. Results showed striking differences between the two species, with IR of 95% (261/274) and 9% (16/177) in Cx. tritaeniorhynchus and Ae. j. japonicus, respectively. Both mosquitoes were susceptible to all three JEV genotypes with significant differences in IR and mean viral titer. Results confirm the primary vector's competence, but the fact that JEV was able to establish in Ae. j. japonicus is of public health significance, and with 2%-16% transmission rate it has the potential to successfully transmit JEV to the next host. This may explain the human cases and infrequent detection in primary vector-free areas. Importantly, Ae. j. japonicus could be a relevant vector spreading the disease into new areas, indicating the need for security measures in areas where the mosquito is distributed or where it may be introduced.
Collapse
Affiliation(s)
- Astri Nur Faizah
- Laboratory of Veterinary Public Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, Japan
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
| | - Daisuke Kobayashi
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
| | - Michael Amoa-Bosompem
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
- Department of Environmental Parasitology, Tokyo Medical and Dental University, Bunkyo, Tokyo, Japan
| | - Yukiko Higa
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
| | - Yoshio Tsuda
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
| | - Kentaro Itokawa
- Pathogen Genomics Center, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
| | - Kozue Miura
- Laboratory of Veterinary Public Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Kazuhiro Hirayama
- Laboratory of Veterinary Public Health, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Kyoko Sawabe
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
| | - Haruhiko Isawa
- Department of Medical Entomology, National Institute of Infectious Diseases, Shinjuku, Tokyo, Japan
- * E-mail:
| |
Collapse
|
33
|
Chapman GE, Sherlock K, Hesson JC, Blagrove MSC, Lycett GJ, Archer D, Solomon T, Baylis M. Laboratory transmission potential of British mosquitoes for equine arboviruses. Parasit Vectors 2020; 13:413. [PMID: 32787904 PMCID: PMC7425075 DOI: 10.1186/s13071-020-04285-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 08/03/2020] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND There has been no evidence of transmission of mosquito-borne arboviruses of equine or human health concern to date in the UK. However, in recent years there have been a number of outbreaks of viral diseases spread by vectors in Europe. These events, in conjunction with increasing rates of globalisation and climate change, have led to concern over the future risk of mosquito-borne viral disease outbreaks in northern Europe and have highlighted the importance of being prepared for potential disease outbreaks. Here we assess several UK mosquito species for their potential to transmit arboviruses important for both equine and human health, as measured by the presence of viral RNA in saliva at different time points after taking an infective blood meal. RESULTS The following wild-caught British mosquitoes were evaluated for their potential as vectors of zoonotic equine arboviruses: Ochlerotatus detritus for Venezuelan equine encephalitis virus (VEEV) and Ross River virus (RRV), and Culiseta annulata and Culex pipiens for Japanese encephalitis virus (JEV). Production of RNA in saliva was demonstrated at varying efficiencies for all mosquito-virus pairs. Ochlerotatus detritus was more permissive for production of RRV RNA in saliva than VEEV RNA. For RRV, 27.3% of mosquitoes expectorated viral RNA at 7 days post-infection when incubated at 21 °C and 50% at 24 °C. Strikingly, 72% of Cx. pipiens produced JEV RNA in saliva after 21 days at 18 °C. For some mosquito-virus pairs, infection and salivary RNA titres reduced over time, suggesting unstable infection dynamics. CONCLUSIONS This study adds to the number of Palaearctic mosquito species that demonstrate expectoration of viral RNA, for arboviruses of importance to human and equine health. This work adds to evidence that native mosquito species should be investigated further for their potential to vector zoonotic mosquito-borne arboviral disease of equines in northern Europe. The evidence that Cx. pipiens is potentially an efficient laboratory vector of JEV at temperatures as low as 18 °C warrants further investigation, as this mosquito is abundant in cooler regions of Europe and is considered an important vector for West Nile Virus, which has a comparable transmission ecology.
Collapse
Affiliation(s)
- Gail E. Chapman
- Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Ken Sherlock
- Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Jenny C. Hesson
- Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Marcus S. C. Blagrove
- Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Gareth J. Lycett
- Vector Biology, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Debra Archer
- Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - Tom Solomon
- Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
- Health Protection Research Unit in Emerging and Zoonotic Infections, University of Liverpool, Liverpool, UK
- Walton Centre NHS Foundation Trust, Liverpool, UK
| | - Matthew Baylis
- Epidemiology and Population Health, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
- Health Protection Research Unit in Emerging and Zoonotic Infections, University of Liverpool, Liverpool, UK
| |
Collapse
|
34
|
Choi JW, Eom HJ, Kim HY. Non-structural protein 1 from Japanese encephalitis virus expressed in E. coli retains its molecular weight and immunogenicity. Protein Expr Purif 2020; 169:105548. [DOI: 10.1016/j.pep.2019.105548] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 11/25/2019] [Accepted: 11/26/2019] [Indexed: 02/06/2023]
|
35
|
Oliveira ARS, Cohnstaedt LW, Noronha LE, Mitzel D, McVey DS, Cernicchiaro N. Perspectives Regarding the Risk of Introduction of the Japanese Encephalitis Virus (JEV) in the United States. Front Vet Sci 2020; 7:48. [PMID: 32118069 PMCID: PMC7019853 DOI: 10.3389/fvets.2020.00048] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 01/20/2020] [Indexed: 12/15/2022] Open
Abstract
Japanese encephalitis (JE) is a zoonotic, emerging disease transmitted by mosquito vectors infected with the Japanese encephalitis virus (JEV). Its potential for emergence into susceptible regions is high, including in the United States (US), and is a reason of economic concern among the agricultural community, and to public health due to high morbidity and mortality rates in humans. While exploring the complexities of interactions involved with viral transmission, we proposed a new outlook on the role of vectors, hosts and the environment under changing conditions. For instance, the role of feral pigs may have been underappreciated in our previous work, given research keeps pointing to the importance of susceptible populations of wild swine in naïve regions as key elements for the introduction of emergent vector-borne diseases. High risk of JEV introduction has been associated with the transportation of infected mosquitoes via aircraft. Nonetheless, no JEV outbreaks have been reported in the US to date and results from a qualitative risk assessment considered the risk of establishment to be negligible under the current conditions (environmental, vector, pathogen, and host). In this work, we discuss virus-vector-host interactions and ecological factors important for virus transmission and spread, review research on the risk of JEV introduction to the US considering the implications of risk dismissal as it relates to past experiences with similar arboviruses, and reflect on future directions, challenges, and implications of a JEV incursion.
Collapse
Affiliation(s)
- Ana R S Oliveira
- Center for Outcomes Research and Epidemiology, Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
| | - Lee W Cohnstaedt
- Arthropod-Borne Animal Diseases Research, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS, United States
| | - Leela E Noronha
- Arthropod-Borne Animal Diseases Research, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS, United States
| | - Dana Mitzel
- Arthropod-Borne Animal Diseases Research, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS, United States
| | - D Scott McVey
- Arthropod-Borne Animal Diseases Research, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS, United States
| | - Natalia Cernicchiaro
- Center for Outcomes Research and Epidemiology, Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, United States
| |
Collapse
|
36
|
Folly AJ, Dorey-Robinson D, Hernández-Triana LM, Phipps LP, Johnson N. Emerging Threats to Animals in the United Kingdom by Arthropod-Borne Diseases. Front Vet Sci 2020; 7:20. [PMID: 32118054 PMCID: PMC7010938 DOI: 10.3389/fvets.2020.00020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 01/10/2020] [Indexed: 01/06/2023] Open
Abstract
Worldwide, arthropod-borne disease transmission represents one of the greatest threats to public and animal health. For the British Isles, an island group on the north-western coast of continental Europe consisting of the United Kingdom (UK) and the Republic of Ireland, physical separation offers a barrier to the introduction of many of the pathogens that affect animals on the rest of the continent. Added to this are strict biosecurity rules at ports of entry and the depauperate vector biodiversity found on the islands. Nevertheless, there are some indigenous arthropod-borne pathogens that cause sporadic outbreaks, such as the tick-borne louping ill virus, found almost exclusively in the British Isles, and a range of piroplasmid infections that are poorly characterized. These provide an ongoing source of infection whose emergence can be unpredictable. In addition, the risk remains for future introductions of both exotic vectors and the pathogens they harbor, and can transmit. Current factors that are driving the increases of both disease transmission and the risk of emergence include marked changes to the climate in the British Isles that have increased summer and winter temperatures, and extended the period over which arthropods are active. There have also been dramatic increases in the distribution of mosquito-borne diseases, such as West Nile and Usutu viruses in mainland Europe that are making the introduction of these pathogens through bird migration increasingly feasible. In addition, the establishment of midge-borne bluetongue virus in the near continent has increased the risk of wind-borne introduction of infected midges and the inadvertent importation of infected cattle. Arguably the greatest risk is associated with the continual increase in the movement of people, pets and trade into the UK. This, in particular, is driving the introduction of invasive arthropod species that either bring disease-causing pathogens, or are known competent vectors, that increase the risk of disease transmission if introduced. The following review documents the current pathogen threats to animals transmitted by mosquitoes, ticks and midges. This includes both indigenous and exotic pathogens to the UK. In the case of exotic pathogens, the pathway and risk of introduction are also discussed.
Collapse
Affiliation(s)
- Arran J. Folly
- Virology Department, Animal and Plant Health Agency (Weybridge), Addlestone, United Kingdom
| | - Daniel Dorey-Robinson
- Virology Department, Animal and Plant Health Agency (Weybridge), Addlestone, United Kingdom
| | | | - L. Paul Phipps
- Virology Department, Animal and Plant Health Agency (Weybridge), Addlestone, United Kingdom
| | - Nicholas Johnson
- Virology Department, Animal and Plant Health Agency (Weybridge), Addlestone, United Kingdom
- Faculty of Health and Medicine, University of Surrey, Guildford, United Kingdom
| |
Collapse
|
37
|
Viral Equine Encephalitis, a Growing Threat to the Horse Population in Europe? Viruses 2019; 12:v12010023. [PMID: 31878129 PMCID: PMC7019608 DOI: 10.3390/v12010023] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/15/2019] [Accepted: 12/17/2019] [Indexed: 12/20/2022] Open
Abstract
Neurological disorders represent an important sanitary and economic threat for the equine industry worldwide. Among nervous diseases, viral encephalitis is of growing concern, due to the emergence of arboviruses and to the high contagiosity of herpesvirus-infected horses. The nature, severity and duration of the clinical signs could be different depending on the etiological agent and its virulence. However, definite diagnosis generally requires the implementation of combinations of direct and/or indirect screening assays in specialized laboratories. The equine practitioner, involved in a mission of prevention and surveillance, plays an important role in the clinical diagnosis of viral encephalitis. The general management of the horse is essentially supportive, focused on controlling pain and inflammation within the central nervous system, preventing injuries and providing supportive care. Despite its high medical relevance and economic impact in the equine industry, vaccines are not always available and there is no specific antiviral therapy. In this review, the major virological, clinical and epidemiological features of the main neuropathogenic viruses inducing encephalitis in equids in Europe, including rabies virus (Rhabdoviridae), Equid herpesviruses (Herpesviridae), Borna disease virus (Bornaviridae) and West Nile virus (Flaviviridae), as well as exotic viruses, will be presented.
Collapse
|
38
|
Zheng B, Wang X, Liu Y, Li Y, Long S, Gu C, Ye J, Xie S, Cao S. Japanese Encephalitis Virus infection induces inflammation of swine testis through RIG-I-NF-ĸB signaling pathway. Vet Microbiol 2019; 238:108430. [PMID: 31648727 DOI: 10.1016/j.vetmic.2019.108430] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 09/03/2019] [Accepted: 09/24/2019] [Indexed: 11/15/2022]
Abstract
Japanese Encephalitis Virus (JEV) is an important zoonotic flavivirus transmitted by mosquitos. JEV infection in sows primarily manifests as a reproductive disease such as abortion and transient infertility while in infected boars, it can cause orchitis. Previous studies mainly focused on the pathogenesis of human encephalitis caused by JEV infection, while few concentrations have been made to unveil the potential mechanism of reproductive dysfunction in JEV-infected pigs. In this study, histopathological analysis and immunohistochemistry staining was performed on testis of JEV-infected boars, indicating that JEV could infect testicular cells and cause inflammatory changes in testis. In vitro assays reveal that primary swine testicular cells and swine testis (ST) cells are highly permissive to JEV and significant inflammatory response was shown during JEV infection. Mechanically, we found that JEV infection increases the expression of retinoic acid-inducible gene I (RIG-I) and activates transcription factor NF-κB. Production of pro-inflammatory cytokines was greatly reduced in JEV infected testicular cells after knockout of RIG-I or treatment with the NF-κB specific inhibitor. In addition, activation of NF-κB was also significantly suppressed upon RIG-I knockout. Taken together, our results reveal that JEV could infect boar testicles, and RIG-I-NF-κB signaling pathway is involved in JEV-induced inflammation in swine testicular cells.
Collapse
Affiliation(s)
- Bohan Zheng
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China; Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Xugang Wang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China; Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Yixin Liu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China; Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Yunchuan Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China; Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Siwen Long
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China; Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Changqin Gu
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Jing Ye
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China; Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Shengsong Xie
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Laboratory of Swine Genetics and Breeding of Ministry of Agriculture, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070, People's Republic of China
| | - Shengbo Cao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China; Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China.
| |
Collapse
|
39
|
Abstract
Japanese encephalitis is a mosquito-borne disease that occurs in Asia and is caused by Japanese encephalitis virus (JEV), a member of the genus Flavivirus. Although many flaviviruses can cause encephalitis, JEV causes particularly severe neurological manifestations. The virus causes loss of more disability-adjusted life years than any other arthropod-borne virus owing to the frequent neurological sequelae of the condition. Despite substantial advances in our understanding of Japanese encephalitis from in vitro studies and animal models, studies of pathogenesis and treatment in humans are lagging behind. Few mechanistic studies have been conducted in humans, and only four clinical trials of therapies for Japanese encephalitis have taken place in the past 10 years despite an estimated incidence of 69,000 cases per year. Previous trials for Japanese encephalitis might have been too small to detect important benefits of potential treatments. Many potential treatment targets exist for Japanese encephalitis, and pathogenesis and virological studies have uncovered mechanisms by which these drugs could work. In this Review, we summarize the epidemiology, clinical features, prevention and treatment of Japanese encephalitis and focus on potential new therapeutic strategies, based on repurposing existing compounds that are already suitable for human use and could be trialled without delay. We use our newly improved understanding of Japanese encephalitis pathogenesis to posit potential treatments and outline some of the many challenges that remain in tackling the disease in humans.
Collapse
|
40
|
Review of Emerging Japanese Encephalitis Virus: New Aspects and Concepts about Entry into the Brain and Inter-Cellular Spreading. Pathogens 2019; 8:pathogens8030111. [PMID: 31357540 PMCID: PMC6789543 DOI: 10.3390/pathogens8030111] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 07/17/2019] [Accepted: 07/22/2019] [Indexed: 12/12/2022] Open
Abstract
Japanese encephalitis virus (JEV) is an emerging flavivirus of the Asia-Pacific region. More than two billion people live in endemic or epidemic areas and are at risk of infection. Recently, the first autochthonous human case was recorded in Africa, and infected birds have been found in Europe. JEV may spread even further to other continents. The first section of this review covers established and new information about the epidemiology of JEV. The subsequent sections focus on the impact of JEV on humans, including the natural course and immunity. Furthermore, new concepts are discussed about JEV’s entry into the brain. Finally, interactions of JEV and host cells are covered, as well as how JEV may spread in the body through latently infected immune cells and cell-to-cell transmission of virions or via other infectious material, including JEV genomic RNA.
Collapse
|
41
|
Lannes N, Garcia-Nicolàs O, Démoulins T, Summerfield A, Filgueira L. CX 3CR1-CX 3CL1-dependent cell-to-cell Japanese encephalitis virus transmission by human microglial cells. Sci Rep 2019; 9:4833. [PMID: 30886214 PMCID: PMC6423114 DOI: 10.1038/s41598-019-41302-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 03/01/2019] [Indexed: 01/10/2023] Open
Abstract
The neurotropic Japanese encephalitis virus (JEV) is responsible for Japanese encephalitis, an uncontrolled inflammatory disease of the central nervous system. Microglia cells are the unique innate immune cell type populating the brain that cross-communicate with neurons via the CX3CR1-CX3CL1 axis. However, microglia may serve as a viral reservoir for JEV. Human microglia are able to transmit JEV infectivity to neighbouring cells in a cell-to-cell contact-dependent manner. Using JEV-treated human blood monocyte-derived microglia, the present study investigates molecular mechanisms behind cell-to-cell virus transmission by human microglia. For that purpose, JEV-associated microglia were co-cultured with JEV susceptible baby hamster kidney cells under various conditions. Here, we show that microglia hosting JEV for up to 10 days were able to transmit the virus to susceptible cells. Interestingly, neutralizing anti-JEV antibodies did not completely abrogate cell-to-cell virus transmission. Hence, intracellular viral RNA could be a contributing source of infectious virus material upon intercellular interactions. Importantly, the CX3CL1-CX3CR1 axis was a key regulator of cell-to-cell virus transmission from JEV-hosting human microglia. Our findings suggest that human microglia may be a source of infection for neuronal populations and sustain JEV brain pathogenesis in long-term infection. Moreover, the present work emphasizes on the critical role of the CX3CR1-CX3CL1 axis in JEV pathogenesis mediating transmission of infectious genomic JEV RNA.
Collapse
Affiliation(s)
- Nils Lannes
- Unit of Anatomy, Department of Medicine, University of Fribourg, Route Albert-Gockel 1, Fribourg, Switzerland.
| | - Obdullio Garcia-Nicolàs
- Institute of Virology and Immunology, Sensemattstrasse 293, Mittelhäusern, Switzerland.,Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Langassstrasse 122, Bern, Switzerland
| | - Thomas Démoulins
- Institute of Virology and Immunology, Sensemattstrasse 293, Mittelhäusern, Switzerland.,Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Langassstrasse 122, Bern, Switzerland
| | - Artur Summerfield
- Institute of Virology and Immunology, Sensemattstrasse 293, Mittelhäusern, Switzerland.,Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Langassstrasse 122, Bern, Switzerland
| | - Luis Filgueira
- Unit of Anatomy, Department of Medicine, University of Fribourg, Route Albert-Gockel 1, Fribourg, Switzerland
| |
Collapse
|
42
|
Potokar M, Jorgačevski J, Zorec R. Astrocytes in Flavivirus Infections. Int J Mol Sci 2019; 20:ijms20030691. [PMID: 30736273 PMCID: PMC6386967 DOI: 10.3390/ijms20030691] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 01/27/2019] [Accepted: 01/29/2019] [Indexed: 12/14/2022] Open
Abstract
Virus infections of the central nervous system (CNS) can manifest in various forms of inflammation, including that of the brain (encephalitis) and spinal cord (myelitis), all of which may have long-lasting deleterious consequences. Although the knowledge of how different viruses affect neural cells is increasing, understanding of the mechanisms by which cells respond to neurotropic viruses remains fragmented. Several virus types have the ability to infect neural tissue, and astrocytes, an abundant and heterogeneous neuroglial cell type and a key element providing CNS homeostasis, are one of the first CNS cell types to get infected. Astrocytes are morphologically closely aligned with neuronal synapses, blood vessels, and ventricle cavities, and thereby have the capacity to functionally interact with neurons and endothelial cells. In this review, we focus on the responses of astrocytes to infection by neurotropic flaviviruses, including tick-borne encephalitis virus (TBEV), Zika virus (ZIKV), West Nile virus (WNV), and Japanese encephalitis virus (JEV), which have all been confirmed to infect astrocytes and cause multiple CNS defects. Understanding these mechanisms may help design new strategies to better contain and mitigate virus- and astrocyte-dependent neuroinflammation.
Collapse
Affiliation(s)
- Maja Potokar
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia.
- Celica BIOMEDICAL, Tehnološki park 24, 1000 Ljubljana, Slovenia.
| | - Jernej Jorgačevski
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia.
- Celica BIOMEDICAL, Tehnološki park 24, 1000 Ljubljana, Slovenia.
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia.
- Celica BIOMEDICAL, Tehnološki park 24, 1000 Ljubljana, Slovenia.
| |
Collapse
|
43
|
Gao X, Liu H, Li X, Fu S, Cao L, Shao N, Zhang W, Wang Q, Lu Z, Lei W, He Y, Cao Y, Wang H, Liang G. Changing Geographic Distribution of Japanese Encephalitis Virus Genotypes, 1935-2017. Vector Borne Zoonotic Dis 2018; 19:35-44. [PMID: 30207876 DOI: 10.1089/vbz.2018.2291] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Japanese encephalitis virus (JEV) is a representative virus of the JEV serogroup in genus Flavivirus, family Flaviviridae. JEV is a mosquito-borne virus that causes Japanese encephalitis (JE), one of the most severe viral encephalitis diseases in the world. JEV is divided into five genotypes (G1-G5), and each genotype has its own distribution pattern. However, the distribution of different JEV genotypes has changed markedly in recent years. JEV G1 has replaced G3 as the dominant genotype in the traditional epidemic areas in Asia, while G3 has spread from Asia to Europe and Africa and caused domestic JE cases in Africa. G2 and G5, which were endemic in Malaysia, exhibited great geographical changes as well. G2 migrated southward and led to prevalence of JE in Australia, while G5 emerged in China and South Korea after decades of silence. Along with these changes, JE occurred in some non-traditional epidemic regions as an emerging infectious disease. The regional changes in JEV pose a great threat to human health, leading to huge disease burdens. Therefore, it is of great importance to strengthen the monitoring of JEV as well as virus genotypes, especially in non-traditional epidemic areas.
Collapse
Affiliation(s)
- Xiaoyan Gao
- 1 Department of Science and Technology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,2 State Key Laboratory of Infectious Disease Prevention and Control, Department of Viral Encephalitis and Arbovirus, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,3 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Hong Liu
- 4 Shandong Provincial Research Center for Bioinformatic Engineering and Technique, School of Life Sciences, Shandong University of Technology, Zibo, China
| | - Xiaolong Li
- 2 State Key Laboratory of Infectious Disease Prevention and Control, Department of Viral Encephalitis and Arbovirus, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,3 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Shihong Fu
- 2 State Key Laboratory of Infectious Disease Prevention and Control, Department of Viral Encephalitis and Arbovirus, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,3 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Lei Cao
- 2 State Key Laboratory of Infectious Disease Prevention and Control, Department of Viral Encephalitis and Arbovirus, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,3 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Nan Shao
- 2 State Key Laboratory of Infectious Disease Prevention and Control, Department of Viral Encephalitis and Arbovirus, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,3 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Weijia Zhang
- 2 State Key Laboratory of Infectious Disease Prevention and Control, Department of Viral Encephalitis and Arbovirus, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,3 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Qianying Wang
- 2 State Key Laboratory of Infectious Disease Prevention and Control, Department of Viral Encephalitis and Arbovirus, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,3 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Zhi Lu
- 2 State Key Laboratory of Infectious Disease Prevention and Control, Department of Viral Encephalitis and Arbovirus, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,3 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Wenwen Lei
- 2 State Key Laboratory of Infectious Disease Prevention and Control, Department of Viral Encephalitis and Arbovirus, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,3 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Ying He
- 2 State Key Laboratory of Infectious Disease Prevention and Control, Department of Viral Encephalitis and Arbovirus, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,3 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Yuxi Cao
- 1 Department of Science and Technology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.,2 State Key Laboratory of Infectious Disease Prevention and Control, Department of Viral Encephalitis and Arbovirus, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Huanyu Wang
- 2 State Key Laboratory of Infectious Disease Prevention and Control, Department of Viral Encephalitis and Arbovirus, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,3 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| | - Guodong Liang
- 2 State Key Laboratory of Infectious Disease Prevention and Control, Department of Viral Encephalitis and Arbovirus, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.,3 Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, China
| |
Collapse
|
44
|
Di Francesco J, Choeung R, Peng B, Pring L, Pang S, Duboz R, Ong S, Sorn S, Tarantola A, Fontenille D, Duong V, Dussart P, Chevalier V, Cappelle J. Comparison of the dynamics of Japanese encephalitis virus circulation in sentinel pigs between a rural and a peri-urban setting in Cambodia. PLoS Negl Trop Dis 2018; 12:e0006644. [PMID: 30138381 PMCID: PMC6107123 DOI: 10.1371/journal.pntd.0006644] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 06/28/2018] [Indexed: 11/18/2022] Open
Abstract
Japanese encephalitis is mainly considered a rural disease, but there is growing evidence of a peri-urban and urban transmission in several countries, including Cambodia. We, therefore, compared the epidemiologic dynamic of Japanese encephalitis between a rural and a peri-urban setting in Cambodia. We monitored two cohorts of 15 pigs and determined the force of infection-rate at which seronegative pigs become positive-in two study farms located in a peri-urban and rural area, respectively. We also studied the mosquito abundance and diversity in proximity of the pigs, as well as the host densities in both areas. All the pigs seroconverted before the age of 6 months. The force of infection was 0.061 per day (95% confidence interval = 0.034-0.098) in the peri-urban cohort and 0.069 per day (95% confidence interval = 0.047-0.099) in the rural cohort. Several differences in the epidemiologic dynamic of Japanese encephalitis between both study sites were highlighted. The later virus amplification in the rural cohort may be linked to the later waning of maternal antibodies, but also to the higher pig density in direct proximity of the studied pigs, which could have led to a dilution of mosquito bites at the farm level. The force of infection was almost identical in both the peri-urban and the rural farms studied, which shifts the classic epidemiologic cycle of the virus. This study is a first step in improving our understanding of Japanese encephalitis virus ecology in different environments with distinct landscapes, human and animal densities.
Collapse
Affiliation(s)
- Juliette Di Francesco
- Institut Pasteur du Cambodge, Epidemiology and Public Health Unit, Phnom Penh, Cambodia
- University of Calgary, Faculty of Veterinary Medicine, Department of Ecosystem and Public Health, Calgary, Canada
- * E-mail:
| | - Rithy Choeung
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - Borin Peng
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - Long Pring
- Royal University of Agriculture, Phnom Penh, Cambodia
| | - Senglong Pang
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - Raphaël Duboz
- Institut Pasteur du Cambodge, Epidemiology and Public Health Unit, Phnom Penh, Cambodia
- UMR ASTRE, CIRAD, INRA, Université de Montpellier, Montpellier, France
| | - Sivuth Ong
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - San Sorn
- Ministry of Agriculture, Forestry, and Fisheries, Department of Animal Health and Production, Phnom Penh, Cambodia
| | - Arnaud Tarantola
- Institut Pasteur du Cambodge, Epidemiology and Public Health Unit, Phnom Penh, Cambodia
| | | | - Veasna Duong
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - Philippe Dussart
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - Véronique Chevalier
- Institut Pasteur du Cambodge, Epidemiology and Public Health Unit, Phnom Penh, Cambodia
- UMR ASTRE, CIRAD, INRA, Université de Montpellier, Montpellier, France
| | - Julien Cappelle
- Institut Pasteur du Cambodge, Epidemiology and Public Health Unit, Phnom Penh, Cambodia
- UMR ASTRE, CIRAD, INRA, Université de Montpellier, Montpellier, France
- UMR EpiA, VetAgro Sup, INRA, Marcy l’étoile, France
| |
Collapse
|
45
|
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.
Collapse
|
46
|
Barzon L, Palù G. Recent developments in vaccines and biological therapies against Japanese encephalitis virus. Expert Opin Biol Ther 2018; 18:851-864. [DOI: 10.1080/14712598.2018.1499721] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Luisa Barzon
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | - Giorgio Palù
- Department of Molecular Medicine, University of Padova, Padova, Italy
| |
Collapse
|
47
|
Preziuso S, Mari S, Mariotti F, Rossi G. Detection of Japanese Encephalitis Virus in bone marrow of healthy young wild birds collected in 1997-2000 in Central Italy. Zoonoses Public Health 2018; 65:798-804. [DOI: 10.1111/zph.12501] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 05/11/2018] [Accepted: 06/10/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Silvia Preziuso
- School of Biosciences and Veterinary Medicine; University of Camerino; Matelica Italy
| | - Subeide Mari
- School of Biosciences and Veterinary Medicine; University of Camerino; Matelica Italy
| | - Francesca Mariotti
- School of Biosciences and Veterinary Medicine; University of Camerino; Matelica Italy
| | - Giacomo Rossi
- School of Biosciences and Veterinary Medicine; University of Camerino; Matelica Italy
| |
Collapse
|
48
|
Abstract
PURPOSE OF REVIEW We examine the present global burden of Japanese encephalitis (JE) in endemic populations, summarize published cases in travelers since 2009, examine current guidelines for vaccination for international travelers, and consider challenges in prevention of this vector-borne disease. RECENT FINDINGS We identified 11 JE cases in travelers that were published in peer-reviewed literature since 2009. JE incidence in endemic countries appears to be declining but the number of JE cases reported to the World Health Organization (WHO) varied from estimates derived from other published reports based on serosurveys or sentinel surveillance. Current JE vaccines appear to be safe and are not associated with delayed hypersensitivity in contrast to the older mouse brain vaccine. Given differences between WHO-reported cases and local surveillance data, future research on true incidence is needed. Regular assessment will inform JE risk in travelers. National and international guidelines on JE vaccination varied; we suggest areas for improvement.
Collapse
|
49
|
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: 70] [Impact Index Per Article: 11.7] [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.
Collapse
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
| |
Collapse
|
50
|
Lindquist L. Recent and historical trends in the epidemiology of Japanese encephalitis and its implication for risk assessment in travellers. J Travel Med 2018; 25:S3-S9. [PMID: 29718434 DOI: 10.1093/jtm/tay006] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 01/17/2018] [Indexed: 01/30/2023]
Abstract
Japanese encephalitis is a major disease in many countries in Asia often visited by both leisure and non-leisure travellers. Although reported cases of Japanese apoptosis (JE) in travellers are relatively few, there are indications that both the number of cases might be underreported and that changes in the epidemiological situation in these parts of Asia may increase the risk, especially non-leisure travellers. Although JE mainly is considered a rural disease urban cases are seen the large economic growth and urbanization of previously rural areas in many for JE high-endemic areas may further add to the risk for JE, especially for business travellers, when visiting newly established peri-urban areas. This review will address these dynamic and unpredictable risks for JE and discuss its possible implications for the traveller.
Collapse
Affiliation(s)
- Lars Lindquist
- Karolinska Institutet, Karolinska University Hospital, SE 141 86 Huddinge, Sweden; Clinic for Infectious Diseases Huddinge I63; SE 141 86 Huddinge, Sweden
| |
Collapse
|