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Dixon AL, Oliveira ARS, Cohnstaedt LW, Mitzel D, Mire C, Cernicchiaro N. Revisiting the risk of introduction of Japanese encephalitis virus (JEV) into the United States - An updated semi-quantitative risk assessment. One Health 2024; 19:100879. [PMID: 39253386 PMCID: PMC11381889 DOI: 10.1016/j.onehlt.2024.100879] [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: 03/24/2024] [Accepted: 08/14/2024] [Indexed: 09/11/2024] Open
Abstract
Japanese encephalitis virus (JEV) is associated with encephalitis in humans and reproductive and neurological illness in pigs. JEV has expanded beyond its native distribution in southeast Asia, with identifications in Europe (2010) and Africa (2016), and most recently, its spread into mainland Australia (2021-2022). The introduction of JEV into the United States (US) is a public health risk, and could also impact animal health and the food supply. To efficiently and cost-effectively manage risk, a better understanding of how and where diseases will be introduced, transmitted, and spread is required. To achieve this objective, we updated our group's previous qualitative risk assessment using an established semi-quantitative risk assessment tool (MINTRISK) to compare the overall rate of introduction and risk, including impacts, of JEV in seven US regions. The rate of introduction from the current region of distribution was considered negligible for the Northeast, Midwest, Rocky Mountain, West, Alaska, and Hawaii regions. The South region was the only region with a pathway that had a non-negligible rate of introduction; infected mosquito eggs and larvae introduced via imported used tires (very low; 95% uncertainty interval (UI) = negligible to high). The overall risk estimate for the South was very high (95% UI = very low to very high). Based on this risk assessment, the South region should be prioritized for surveillance activities to ensure the early detection of JEV. The assumptions used in this risk assessment, due to the lack of information about the global movement of mosquitoes, number of feral pigs in the US, the role of non-ardeid wild birds in transmission, and the magnitude of the basic reproduction ratio of JEV in a novel region, need to be fully considered as these impact the estimated probability of establishment.
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Affiliation(s)
- Andrea L Dixon
- Center for Outcomes Research and Epidemiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
| | - Ana R S Oliveira
- Department of Population Health & Reproduction, School of Veterinary Medicine, University of California, Davis, CA, USA
| | - Lee W Cohnstaedt
- National Bio- and Agro-Defense Facility, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS, USA
| | - Dana Mitzel
- National Bio- and Agro-Defense Facility, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS, USA
| | - Chad Mire
- National Bio- and Agro-Defense Facility, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS, USA
| | - Natalia Cernicchiaro
- Center for Outcomes Research and Epidemiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
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Dhanalakshmi M, Dhanze H, Bhilegaonkar KN, Mote A, Gupta I, Agri H, Di Bari C, Singh BB. Seroprevalence of Japanese encephalitis virus in pig populations of Tamil Nadu, India: Exploring the tropical endemic link of virus. Comp Immunol Microbiol Infect Dis 2024; 110:102189. [PMID: 38718722 DOI: 10.1016/j.cimid.2024.102189] [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: 03/19/2024] [Revised: 04/26/2024] [Accepted: 04/29/2024] [Indexed: 06/11/2024]
Abstract
Japanese encephalitis virus (JEV) is a major cause of encephalitis in Southeast Asia. Tamil Nadu, a state located in the southern part of India, contributes substantially to the national burden of human JE cases every year. However, limited information is available on the epidemiology of JE in pig populations of Tamil Nadu. A cross-sectional study was conducted to assess JEV prevalence in pig populations of Tamil Nadu. A total of 710 pigs reared in 118 farms across 10 districts of Tamil Nadu were sampled using multistage cluster random sampling. Serum samples were analyzed for their JEV status using Immunoglobulin M (IgM) and Immunoglobulin G (IgG) Enzyme-Linked Immunosorbent Assay (ELISA). At the animal-level, the apparent JEV seroprevalence was 60.4% (95% CI: 56.8% - 64.0%) and the true seroprevalence was 50.1% (95% CI: 47.0% - 53.2%). The herd-level apparent seroprevalence was 94.1% (95% CI: 88.1% - 97.5%) and the true seroprevalence was 93.3% (95% CI: 89.5% - 96.2%). The intensity of JEV circulation was high in all the districts, with seroprevalence ranging between 43% and 100%. Pigs across all age categories were seropositive and a high overall seroprevalence of 95.2% (95% CI: 76.2% - 99.9%) was recorded in pigs older than 12 months. JEV seropositivity was recorded in all the seasons but the prevalence peaked in the monsoon (67.9%, 95% CI: 61.1% - 74.2%) followed by winter (65.1%, 95%CI: 57.4% - 72.2%) and summer (53.3%, 95% CI: 47.8% - 58.8%) seasons. The results indicate that JEV is endemic in pigs populations of the state and a one health approach is essential with collaborative actions from animal and public health authorities to control JE in Tamil Nadu, India.
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Affiliation(s)
- M Dhanalakshmi
- Division of Veterinary Public Health, ICAR - Indian Veterinary Research Institute, Uttar Pradesh, India; Veterinary College and Research Institute, Orathanadu, Tamil Nadu Veterinary and Animal Sciences University, Chennai, India
| | - Himani Dhanze
- Division of Veterinary Public Health, ICAR - Indian Veterinary Research Institute, Uttar Pradesh, India.
| | - K N Bhilegaonkar
- Division of Veterinary Public Health, ICAR - Indian Veterinary Research Institute, Uttar Pradesh, India
| | - Akash Mote
- Division of Veterinary Public Health, ICAR - Indian Veterinary Research Institute, Uttar Pradesh, India
| | - Ishita Gupta
- Division of Veterinary Public Health, ICAR - Indian Veterinary Research Institute, Uttar Pradesh, India
| | - Himani Agri
- Division of Veterinary Epidemiology, ICAR - Indian Veterinary Research Institute, Uttar Pradesh, India
| | | | - Balbir B Singh
- Centre for One Health, Guru Angad Dev Veterinary & Animal Sciences University, Punjab, India
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Dhanze H, Singh BB, Walsh M, Kumar MS, Kumar A, Bhilegaonkar KN, Brookes VJ. Spatio-temporal epidemiology of Japanese encephalitis virus infection in pig populations of eastern Uttar Pradesh, India, 2013-2022. Zoonoses Public Health 2024; 71:429-441. [PMID: 38484761 DOI: 10.1111/zph.13123] [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: 07/18/2023] [Revised: 02/25/2024] [Accepted: 03/01/2024] [Indexed: 05/08/2024]
Abstract
AIMS Japanese encephalitis (JE) is endemic in India. Although pigs are considered important hosts and sentinels for JE outbreaks in people, limited information is available on JE virus (JEV) surveillance in pigs. METHODS AND RESULTS We investigated the spatio-temporal distribution of JEV seroprevalence and its association with climate variables in 4451 samples from pigs in 10 districts of eastern Uttar Pradesh, India, over 10 years from 2013 to 2022. The mean seroprevalence of IgG (2013-2022) and IgM (2017-2022) was 14% (95% CI 12.8-15.2) and 10.98% (95% CI 9.8-12.2), respectively. Throughout the region, higher seroprevalence from 2013 to 2017 was observed and was highly variable with no predictable spatio-temporal pattern between districts. Seroprevalence of up to 60.8% in Sant Kabir Nagar in 2016 and 69.5% in Gorakhpur district in 2017 for IgG and IgM was observed, respectively. IgG seroprevalence did not increase with age. Monthly time-series decomposition of IgG and IgM seroprevalence demonstrated annual cyclicity (3-4 peaks) with seasonality (higher, broader peaks in the summer and monsoon periods). However, most variance was due to the overall trend and the random components of the time series. Autoregressive time-series modelling of pigs sampled from Gorakhpur was insufficiently predictive for forecasting; however, an inverse association between humidity (but not rainfall or temperature) was observed. CONCLUSIONS Detection patterns confirm seasonal epidemic periods within year-round endemicity in pigs in eastern Uttar Pradesh. Lack of increasing age-associated seroprevalence indicates that JEV might not be immunizing in pigs which needs further investigation because models that inform public health interventions for JEV could be inaccurate if assuming long-term immunity in pigs. Although pigs are considered sentinels for human outbreaks, sufficient timeliness using sero-surveillance in pigs to inform public health interventions to prevent JEV in people will require more nuanced modelling than seroprevalence and broad climate variables alone.
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Affiliation(s)
- Himani Dhanze
- Indian Veterinary Research Institute, Bareilly, Uttar Pradesh, India
| | - Balbir B Singh
- Guru Angad Dev Veterinary and Animal Sciences University (GADVASU), Ludhiana, Punjab, India
| | - Michael Walsh
- Sydney School of Public Health, Faculty of Medicine and Health, The University of Sydney, Camperdown, New South Wales, Australia
- Sydney Infectious Diseases Institute, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia
- One Health Centre, The Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India
- The Prasanna School of Public Health, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - M Suman Kumar
- Indian Veterinary Research Institute, Bareilly, Uttar Pradesh, India
| | - Amit Kumar
- Indian Veterinary Research Institute, Bareilly, Uttar Pradesh, India
| | | | - Victoria J Brookes
- Sydney Infectious Diseases Institute, Faculty of Medicine and Health, The University of Sydney, Westmead, New South Wales, Australia
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, Camperdown, New South Wales, Australia
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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 PMCID: PMC11092019 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.
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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
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Moore KT, Mangan MJ, Linnegar B, Athni TS, McCallum HI, Trewin BJ, Skinner E. Australian vertebrate hosts of Japanese encephalitis virus; a review of the evidence. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.23.590833. [PMID: 38712158 PMCID: PMC11071400 DOI: 10.1101/2024.04.23.590833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Japanese Encephalitis Virus (JEV) transmission in temperate Australia has underscored a critical need to characterise transmission pathways and identify probable hosts of infection within the country. This systematic review consolidates existing research on the vertebrate hosts of JEV that are known to exist in Australia. Specifically, we aim to identify probable species for JEV transmission, their potential role as either a spillover or maintenance host and identify critical knowledge gaps. Data were extracted from studies involving experimental infection, seroprevalence, and virus isolation and were available for 22 vertebrate species known to reside in Australia. A host competence score was calculated to assess the potential for a given species to infect JEV vectors and to quantity their possible role in JEV transmission. Based on the host competence score and ecology of each species, we find ardeid birds, feral pigs, and flying foxes have potential as maintenance hosts for JEV in the Australian context. We also note that brushtail possums and domestic pigs have potential as spillover hosts under certain outbreak conditions. However, evidence to confirm these roles in localized transmission or outbreaks is sparse, emphasizing the need for further targeted research. This review provides a foundation for future investigations into JEV transmission in Australia, advocating for enhanced surveillance and standardized research methodologies to better understand and mitigate the virus's impact.
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Affiliation(s)
- Kevin T. Moore
- Centre for Planetary Health and Food Security, Griffith University, Gold Coast, QLD 4222, Australia
| | - Madelyn J. Mangan
- Centre for Planetary Health and Food Security, Griffith University, Gold Coast, QLD 4222, Australia
| | - Belinda Linnegar
- Centre for Planetary Health and Food Security, Griffith University, Gold Coast, QLD 4222, Australia
| | - Tejas S. Athni
- Harvard Medical School, Boston, MA 02115, USA
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Hamish I. McCallum
- Centre for Planetary Health and Food Security, Griffith University, Gold Coast, QLD 4222, Australia
| | | | - Eloise Skinner
- Centre for Planetary Health and Food Security, Griffith University, Gold Coast, QLD 4222, Australia
- Department of Biology, Stanford University, Stanford, CA 94305, USA
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Kardena IM, Adi AAAM, Astawa INM, Oka IBM, Sahibzada S, Bruce M, O’Dea M. Seroconversion, genotyping, and potential mosquito vector identification of Japanese encephalitis virus in pig sentinel settings in Bali, Indonesia. Vet World 2024; 17:89-98. [PMID: 38406355 PMCID: PMC10884589 DOI: 10.14202/vetworld.2024.89-98] [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: 09/05/2023] [Accepted: 12/05/2023] [Indexed: 02/27/2024] Open
Abstract
Background and Aims Despite the endemicity of Japanese encephalitis virus (JEV) in humans and animals in the Province of Bali, Indonesia, there is little data on whether seroconversion to the virus occurs in pigs, JEV genotypes circulating, and it's potential mosquito vectors in the area. The aims of this study were to (i) Determine whether JEV infection in Balinese pigs occurs before reaching their sexual maturity, (ii) identify the genotypes of circulating JEV, and (iii) identify potential JEV mosquito vectors at the study sites in urban and peri-urban areas of Bali. Materials and Methods Sixteen 1-week-old Landrace piglets from two different sows were housed in Denpasar. Similarly, 18 one-week-old mixed-breed piglets of two different sows were housed in Badung Regency. The piglets were bled every 1 to 4 weeks for up to 24 weeks. Serum samples from the 11 piglets were tested for antibodies against JEV, and seroconversion-suspected sera were titrated using an enzyme-linked immunosorbent assay. Blood of seroconverted sera from pigs were tested using polymerase chain reaction (PCR) to detect the genetic sequence of JEV. The mosquitoes in the sentinels were trapped throughout the study period to identify the potential mosquito vectors of JEV. Results Antibodies were detected in most of the selected piglets' sera from weeks 1 to 24 of their age. However, sera of pig B9 collected from the sentinel setting in Badung Regency showed a four-fold increase in antibody titer from week 4 to week 8, indicating seroconversion. PCR testing of blood from B9 (pooled blood sample collected from week 5 to week 8) identified JEV nucleic acids, which were phylogenetically classified as belonging to the JEV genotype III. Meanwhile, 1271 of two genera of mosquitoes, Anopheles spp. and Culex spp. were trapped in the pig sentinels. Conclusion JEV seroconversion likely occurs before the pig reaches sexual maturity in Badung Regency. Sequence data indicate that JEV genotype III is circulating in the pig sentinel setting in the regency; however, circulating genotypes need to be clarified through increased surveillance. Meanwhile, Culex spp. and most likely Culex quinquefasciatus and Anopheles spp. were the dominant mosquitoes present in the study sites set in the urban area of Denpasar and peri-urban areas of Badung, Bali, indicating that these are likely vectors in spread of JEV in the region.
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Affiliation(s)
- I Made Kardena
- Department of Pathobiology, Faculty of Veterinary Medicine, Udayana University, Jalan PB Sudirman, Denpasar, Bali, 80234, Indonesia
- School of Veterinary Medicine and Centre for Biosecurity and One Health, Harry Butler Institute, Murdoch University, Perth, Western Australia, 6150, Australia
| | - Anak Agung Ayu Mirah Adi
- Department of Pathobiology, Faculty of Veterinary Medicine, Udayana University, Jalan PB Sudirman, Denpasar, Bali, 80234, Indonesia
| | - I Nyoman Mantik Astawa
- Department of Pathobiology, Faculty of Veterinary Medicine, Udayana University, Jalan PB Sudirman, Denpasar, Bali, 80234, Indonesia
| | - Ida Bagus Made Oka
- Department of Pathobiology, Faculty of Veterinary Medicine, Udayana University, Jalan PB Sudirman, Denpasar, Bali, 80234, Indonesia
| | - Shafi Sahibzada
- School of Veterinary Medicine and Centre for Biosecurity and One Health, Harry Butler Institute, Murdoch University, Perth, Western Australia, 6150, Australia
- Australian Centre for Disease Preparedness, Commonwealth Scientific and Industrial Research Organization, Geelong, VIC 3220, Australia
| | - Mieghan Bruce
- School of Veterinary Medicine and Centre for Biosecurity and One Health, Harry Butler Institute, Murdoch University, Perth, Western Australia, 6150, Australia
| | - Mark O’Dea
- School of Veterinary Medicine and Centre for Biosecurity and One Health, Harry Butler Institute, Murdoch University, Perth, Western Australia, 6150, Australia
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Morris RS, Bingham PC. Japanese encephalitis virus: epidemiology and risk-based surveillance approaches for New Zealand. N Z Vet J 2023; 71:283-294. [PMID: 37621178 DOI: 10.1080/00480169.2023.2248054] [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: 03/15/2023] [Accepted: 08/06/2023] [Indexed: 08/26/2023]
Abstract
The introduction and subsequent rapid spread of Japanese encephalitis virus genotype IV across all Australian mainland states and the Northern Territory since late 2021 has increased the risk of an incursion of this mosquito-transmitted zoonotic virus disease into New Zealand, with serious implications for both animal and human health. The potential modes of entry are through introduction of infected mosquitoes as hitchhikers on ships or aircraft, windborne transfer of mosquitoes, or arrival of infected reservoir bird species. A competent vector mosquito, Culex quinquefasciatus, is endemic in New Zealand and other mosquito species may also become involved. If infection becomes established in New Zealand, the scale of transmission may be considerably less than has occurred in Australia because climatic and epidemiological factors are not so favourable. Early evidence of an incursion could come from detection of clinical disease in horses or pigs, or from human cases. Targeted surveillance to confirm or refute indications of an incursion could be undertaken by antibody detection in a number of species. Dogs have been shown to be a particularly valuable sentinel species due to their cohabitation with people and high seroconversion rate. Other novel methods of surveillance could include reverse transcriptase PCR (RT-PCR) on oronasal secretions of pigs. Should evidence of the disease be detected, prompt action would be required to vaccinate at-risk human populations and clarify the epidemiological situation with respect to mammalian hosts and mosquito vector species, including whether a new mosquito species had arrived in the country.Abbreviations: AHL: Animal Health Laboratory; JE: Japanese encephalitis disease; JEV: Japanese encephalitis virus; RT-PCR: Reverse transcriptase PCR.
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Affiliation(s)
- R S Morris
- MorVet Ltd., Masterton, New Zealand
- Tāwharau Ora - School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - P C Bingham
- Diagnostic and Surveillance Services Directorate, Operations Branch, Ministry for Primary Industries, Wallaceville, New Zealand
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Hsu JY, Hung CC, Tsou TP, Chen WC. Epidemiology and risk factors of Japanese encephalitis in Taiwan, 2010-2022. PLoS Negl Trop Dis 2023; 17:e0011421. [PMID: 37782654 PMCID: PMC10569588 DOI: 10.1371/journal.pntd.0011421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 10/12/2023] [Accepted: 09/24/2023] [Indexed: 10/04/2023] Open
Abstract
INTRODUCTION Taiwan introduced a two-dose inactivated Japanese encephalitis (JE) mouse brain-derived (JE-MB) vaccine into routine childhood immunization in 1968, with booster vaccination implemented in 1974 and 1983. In 2017, JE-MB vaccine was replaced by a two-dose live-attenuated chimeric vaccine (JE-CV). After implementation of JE vaccination programs, JE cases have shifted from children to adults. In this study, we described the JE epidemiology and identify high-risk groups to further inform vaccine policy. METHODOLOGY/PRINCIPAL FINDINGS We extracted data from Taiwan's notifiable disease surveillance database, vital statistics, and employment statistics from 2010 to 2022. Diagnosis of JE was confirmed by JE seroconversion, a four-fold increase in virus-specific antibodies, a positive JE viral nucleic-acid test, or JE virus isolation. From 2010 to 2022, a total of 313 cases of JE were diagnosed, resulting in an overall incidence rate of 0.10 cases per 100,000 person-years and a mortality rate of 0.006 per 100,000 population per year. Among these patients, 64% were male, and the median age was 51 years (range 0-82). Compared with people born in or after 1976 (vaccinated with four doses of JE-MB vaccine or two doses of JE-CV), those born in or before 1962 (unvaccinated) and those born during 1963-1975 (vaccinated with two or three doses of JE-MB vaccine) had a 4.2-fold (95% confidence interval [CI] 3.0-5.7) and 5.9-fold (95% CI 4.3-8.1) higher risk of JE, respectively. The relative risk of working in agriculture, forestry, fishing, or animal husbandry, compared to other occupations, was 5.0 (95% CI 3.5-7.0). CONCLUSIONS/SIGNIFICANCE In Taiwan, individuals born before 1976 and those employed in agriculture, forestry, fishing, or animal husbandry had a higher risk of JE. We recommend JE vaccination for people in these high-risk groups who have not been fully vaccinated or have an unknown vaccination history.
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Affiliation(s)
- Jen-Yu Hsu
- Department of Occupational Medicine and Clinical Toxicology, Taipei Veterans General Hospital, Taipei, Taiwan
- Centers for Disease Control, Ministry of Health and Welfare, Taipei, Taiwan
- School of Medicine, College of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chien-Ching Hung
- Department of Tropical Medicine and Parasitology, National Taiwan University College of Medicine, Taipei, Taiwan
- Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
- Department of Internal Medicine, National Taiwan University Hospital Yunlin Branch, Yunlin, Taiwan
| | - Tsung-Pei Tsou
- Centers for Disease Control, Ministry of Health and Welfare, Taipei, Taiwan
| | - Wan-Chin Chen
- Centers for Disease Control, Ministry of Health and Welfare, Taipei, Taiwan
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Kumar SS, Dhanze H, Mehta D, Hussain M, Gupta M, Kumar MS. Sero-molecular epidemiology of Japanese encephalitis virus in swine population of western Uttar Pradesh, India: Unraveling the geographical expansion of the virus. J Vector Borne Dis 2023; 60:292-299. [PMID: 37843240 DOI: 10.4103/0972-9062.374041] [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] [Indexed: 10/17/2023] Open
Abstract
BACKGROUND & OBJECTIVES Swine is a good sentinel for forecast of Japanese encephalitis virus (JEV) outbreaks in humans. The present study was envisaged with objectives to know the sero-conversion period of JEV and to assess the prevalence of JEV in swine population of western Uttar Pradesh state of India. METHODS A total of 252 swine serum samples were screened using IgM ELISA over the period of one year to determine the sero-conversion rate and compared seasonally to check the transmission peak of virus. Further, 321 swine blood and serum samples were collected from all seven divisions of western Uttar Pradesh to determine prevalence of JEV using real time RT-PCR and ELISA. RESULTS Seasonal sero-conversion rate was high during monsoon and post-monsoon (32%) followed by winter (22.91%) and summer (10.71%) seasons. The sero-conversion was observed in all months indicating viral activity throughout the year in the region. The low degree of correlation was found between meteorological variables (day temperature, rainfall) and sero-conversion rate. A total of 52 samples (16.19%) were found positive by real time RT-PCR while sero-positivity of 29.91% was observed using IgG and IgM ELISA(s). The overall prevalence of JEV was 39.25%. INTERPRETATION & CONCLUSION The presence of JEV was recorded throughout the year with peak occurrence during monsoon and post-monsoon season indicating that virus has spread its realm to western region of the state. The information generated in the present study will aid in initiating timely vector control measures and human vaccination program to mitigate risk of JEV infection in the region.
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Affiliation(s)
- Santhosh S Kumar
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
| | - Himani Dhanze
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
| | - Deepa Mehta
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
| | - Mir Hussain
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
| | - Megha Gupta
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
| | - M Suman Kumar
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India
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Qin L, Fan W, Zheng F, Chen H, Qian P, Li X. Swine IFI6 confers antiviral effects against Japanese encephalitis virus in vitro and in vivo. J Gen Virol 2023; 104. [PMID: 37097881 DOI: 10.1099/jgv.0.001847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2023] Open
Abstract
Swine are considered to be an important intermediate host in the cycle of Japanese encephalitis virus (JEV) infection. Most existing antiviral studies of JEV mainly focus on the host factor of the dead-end hosts. However, little research has addressed this in swine. Here, we found that swine interferon alpha-inducible protein 6 (sIFI6) possessed antiviral activity against JEV. In vitro studies showed that overexpression of sIFI6 inhibited the infection of JEV, while sIFI6 knockdown enhanced the infection of JEV in PK-15 cells. In addition, we also found that the structural integrity of sIFI6 was required by anti-JEV activity and that sIFI6 interacted with JEV nonstructural protein 4A (NS4A), an integral membrane protein with a pivotal function in replication complex during JEV replication. The interaction domain was mapped to the fourth transmembrane domain (TMD), also known as the 2K peptide of NS4A. The antiviral activity of sIFI6 was regulated by endoplasmic reticulum (ER) stress-related protein, Bip. In vivo studies revealed that sIFI6 alleviated symptoms of JEV infection in C57BL/6 mice. In addition, the antiviral spectrum of sIFI6 showed that sIFI6 specifically inhibited JEV infection. In conclusion, this study identified sIFI6 as a host factor against JEV infection for the first time. Our findings provide a potential drug target against JEV infection.
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Affiliation(s)
- Liuxing Qin
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Wenchun Fan
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Feiteng Zheng
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Huanchun Chen
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, PR China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, Wuhan 430070, PR China
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, 430070, PR China
| | - Ping Qian
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, PR China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, Wuhan 430070, PR China
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, 430070, PR China
| | - Xiangmin Li
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, PR China
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, PR China
- Key Laboratory of Development of Veterinary Diagnostic Products, Ministry of Agriculture, Wuhan 430070, PR China
- Key Laboratory of Prevention and Control for African Swine Fever and Other Major Pig Diseases, Ministry of Agriculture and Rural Affairs, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, 430070, PR China
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11
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Zhao G, Gao Y, Shi N, Zhang S, Xiao P, Zhang J, Xie C, Ha Z, Feng S, Li C, Zhang X, Xie Y, Yu N, Zhang H, Bi J, Jin N. Molecular Detection and Genetic Characterization of Japanese Encephalitis Virus in Animals from 11 Provinces in China. Viruses 2023; 15:v15030625. [PMID: 36992334 PMCID: PMC10051441 DOI: 10.3390/v15030625] [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: 01/05/2023] [Revised: 02/14/2023] [Accepted: 02/20/2023] [Indexed: 03/03/2023] Open
Abstract
Japanese encephalitis virus (JEV), which uses a mosquito primary vector and swine as a reservoir host, poses a significant risk to human and animal health. JEV can be detected in cattle, goats and dogs. A molecular epidemiological survey of JEV was conducted in 3105 mammals from five species, swine, fox, racoon dog, yak and goat, and 17,300 mosquitoes from 11 Chinese provinces. JEV was detected in pigs from Heilongjiang (12/328, 3.66%), Jilin (17/642, 2.65%), Shandong (14/832, 1.68%), Guangxi (8/278, 2.88%) and Inner Mongolia (9/952, 0.94%); in goats (1/51, 1.96%) from Tibet; and mosquitoes (6/131, 4.58%) from Yunnan. A total of 13 JEV envelope (E) gene sequences were amplified in pigs from Heilongjiang (5/13), Jilin (2/13) and Guangxi (6/13). Swine had the highest JEV infection rate of any animal species, and the highest infection rates were found in Heilongjiang. Phylogenetic analysis indicated that the predominant strain in Northern China was genotype I. Mutations were found at residues 76, 95, 123, 138, 244, 474 and 475 of E protein but all sequences had predicted glycosylation sites at ′N154. Three strains lacked the threonine 76 phosphorylation site from non-specific (unsp) and protein kinase G (PKG) site predictions; one lacked the threonine 186 phosphorylation site from protein kinase II (CKII) prediction; and one lacked the tyrosine 90 phosphorylation site from epidermal growth factor receptor (EGFR) prediction. The aim of the current study was to contribute to JEV prevention and control through the characterization of its molecular epidemiology and prediction of functional changes due to E-protein mutations.
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Affiliation(s)
- Guanyu Zhao
- College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Yan Gao
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Ning Shi
- College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Shiheng Zhang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Pengpeng Xiao
- Wenzhou Key Laboratory for Virology and Immunology, Institute of Virology, Wenzhou University, Wenzhou 325035, China
| | - Jiaqi Zhang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Changzhan Xie
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Zhuo Ha
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Sheng Feng
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Chenghui Li
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Xuancheng Zhang
- College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Yubiao Xie
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Ning Yu
- College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - He Zhang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
- Correspondence: (H.Z.); (J.B.); (N.J.)
| | - Junlong Bi
- College of Animal Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
- Correspondence: (H.Z.); (J.B.); (N.J.)
| | - Ningyi Jin
- College of Veterinary Medicine, Jilin University, Changchun 130062, China
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
- Correspondence: (H.Z.); (J.B.); (N.J.)
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12
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Individual and Herd-Level Seroprevalence in Association with Potential Risk Factors of Japanese Encephalitis in Pigs Collected from Urban, Periurban, and Rural Areas of Bali, Indonesia. Vet Med Int 2023; 2023:9682657. [PMID: 36844471 PMCID: PMC9946736 DOI: 10.1155/2023/9682657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 01/30/2023] [Accepted: 01/31/2023] [Indexed: 02/17/2023] Open
Abstract
A study to assess the seroprevalence antibodies against JEV in pigs in Denpasar, Badung, and Karangasem as the representatives of urban, periurban, and rural areas in the province of Bali was conducted. Sampled pigs' blood was collected and their sera were tested for antibody detection using commercial IgG ELISA. A standard questionnaire was used to interview the pig owners or farmers to identify the determinants associated with the seropositivity of the antibodies. Overall, 96.6% (95% CI: 94.5-98.1) of 443 pig sera in individual animal-level seroprevalence were seropositive to the ELISA. Karangasem had the highest test prevalence at 97.3% (95% CI: 93.1-99.2) while Badung had a slightly lower prevalence at 96.6% (95% CI: 92.2-98.9), and Denpasar had the lowest prevalence at 96% (95% CI: 91.5-98.5) (p=0.84). In herd-level seroprevalence, all sampled herds contained one or more seropositive pigs (overall herd-level seroprevalence 100% [95% CI: 97.7-100]). No animal-level factors were significantly associated with seropositivity (all p values >0.05). For the herd-level risk factors relating to pig management and husbandry practices adopted, no analysis model could be generated, as all the sampled herds were seropositive. More than 90% seroprevalence detected in this study indicates high natural JEV infection occurred in pigs, which highlights the high public health risk of the infection in the areas.
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Furlong M, Adamu AM, Hoskins A, Russell TL, Gummow B, Golchin M, Hickson RI, Horwood PF. Japanese Encephalitis Enzootic and Epidemic Risks across Australia. Viruses 2023; 15:v15020450. [PMID: 36851664 PMCID: PMC9962251 DOI: 10.3390/v15020450] [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: 12/20/2022] [Revised: 01/30/2023] [Accepted: 02/01/2023] [Indexed: 02/08/2023] Open
Abstract
Japanese encephalitis virus (JEV) is an arboviral, encephalitogenic, zoonotic flavivirus characterized by its complex epidemiology whose transmission cycle involves reservoir and amplifying hosts, competent vector species and optimal environmental conditions. Although typically endemic in Asia and parts of the Pacific Islands, unprecedented outbreaks in both humans and domestic pigs in southeastern Australia emphasize the virus' expanding geographical range. To estimate areas at highest risk of JEV transmission in Australia, ecological niche models of vectors and waterbirds, a sample of piggery coordinates and feral pig population density models were combined using mathematical and geospatial mapping techniques. These results highlight that both coastal and inland regions across the continent are estimated to have varying risks of enzootic and/or epidemic JEV transmission. We recommend increased surveillance of waterbirds, feral pigs and mosquito populations in areas where domestic pigs and human populations are present.
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Affiliation(s)
- Morgan Furlong
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4811, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD 4811, Australia
| | - Andrew M. Adamu
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4811, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD 4811, Australia
| | - Andrew Hoskins
- Commonwealth Scientific Industrial Research Organisation (CSIRO), Townsville, QLD 4811, Australia
| | - Tanya L. Russell
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4870, Australia
| | - Bruce Gummow
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4811, Australia
| | - Maryam Golchin
- Commonwealth Scientific Industrial Research Organisation (CSIRO), Townsville, QLD 4811, Australia
| | - Roslyn I. Hickson
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4811, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD 4811, Australia
- Commonwealth Scientific Industrial Research Organisation (CSIRO), Townsville, QLD 4811, Australia
- Correspondence: (R.I.H.); (P.F.H.); Tel.: +61-7-4781-6106
| | - Paul F. Horwood
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4811, Australia
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD 4811, Australia
- Correspondence: (R.I.H.); (P.F.H.); Tel.: +61-7-4781-6106
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14
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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: 32] [Impact Index Per Article: 16.0] [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.
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Xu B, Gong P, Zhang Y, Wang Y, Tao D, Fu L, Khazalwa EM, Liu H, Zhao S, Zhang X, Xie S. A one-tube rapid visual CRISPR assay for the field detection of Japanese encephalitis virus. Virus Res 2022; 319:198869. [PMID: 35842016 DOI: 10.1016/j.virusres.2022.198869] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 07/08/2022] [Accepted: 07/12/2022] [Indexed: 12/26/2022]
Abstract
Early and rapid detection of Japanese encephalitis virus (JEV) is necessary for timely preventive and control measures. However, JEV RNA detection remains challenging due to the low level of viremia. In this study, a RApid VIsual CRISPR (RAVI-CRISPR) assay based on reverse transcription loop-mediated isothermal amplification (RT-LAMP) and CRISPR/Cas12a targeting was developed for easy detection of JEV in the field. We showed successful detection of 8.97 or more copies of the C gene sequence of JEV RNA within approximately 60 min. This assay also displayed no cross-reactivity with other porcine pathogens. We applied our one-tube RAVI-CRISPR assay to 18 brain tissue sample for JE diagnosis. The results from both fluorescence intensity measurements and directly naked-eye visualization were consistent with those from real-time PCR analysis. Taken together, our results showed that one-tube RAVI-CRISPR assay is robust, convenient, sensitive, specific, affordable, and potentially adaptable to on-site detection or surveillance of JEV in clinical and vector samples.
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Affiliation(s)
- Bingrong Xu
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Ping Gong
- Institute of Animal Husbandry and Veterinary, Wuhan Academy of Agricultural Science, Wuhan 430208, PR China
| | - Yi Zhang
- Institute of Animal Husbandry and Veterinary, Wuhan Academy of Agricultural Science, Wuhan 430208, PR China
| | - Yuan Wang
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Dagang Tao
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Lanting Fu
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Emmanuel M Khazalwa
- International Livestock Research Institute (ILRI), P.O. Box 30709, Nairobi 00100, Kenya
| | - Hailong Liu
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Shuhong Zhao
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China; Hubei Hongshan Laboratory, Frontiers Science Center for Animal Breeding and Sustainable Production, Wuhan 430070, PR China
| | - Xuying Zhang
- Institute for Animal Breeding and Genetics, University of Veterinary Medicine Hannover, Bünteweg 17p, Hannover 30559, Germany.
| | - Shengsong Xie
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education & Key Lab of Swine Genetics and Breeding of Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan 430070, PR China; Hubei Hongshan Laboratory, Frontiers Science Center for Animal Breeding and Sustainable Production, Wuhan 430070, PR China.
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16
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Hoad VC, Kiely P, Seed CR, Viennet E, Gosbell IB. An Outbreak of Japanese Encephalitis Virus in Australia; What Is the Risk to Blood Safety? Viruses 2022; 14:1935. [PMID: 36146742 PMCID: PMC9501196 DOI: 10.3390/v14091935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022] Open
Abstract
A widespread outbreak of Japanese encephalitis virus (JEV) was detected in mainland Australia in 2022 in a previous non-endemic area. Given JEV is known to be transfusion-transmissible, a rapid blood-safety risk assessment was performed using a simple deterministic model to estimate the risk to blood safety over a 3-month outbreak period during which 234,212 donors attended. The cumulative estimated incidence in donors was 82 infections with an estimated 4.26 viraemic components issued, 1.58 resulting in transfusion-transmission and an estimated risk of encephalitis of 1 in 4.3 million per component transfused over the risk period. Australia has initiated a robust public health response, including vector control, animal control and movement, and surveillance. Unlike West Nile virus, there is an effective vaccine that is being rolled-out to those at higher risk. Risk evaluation considered options such as restricting those potentially at risk to plasma for fractionation, which incorporates additional pathogen reduction, introducing a screening test, physicochemical pathogen reduction, quarantine, post donation illness policy changes and a new donor deferral. However, except for introducing a new deferral to potentially cover rare flavivirus risks, no option resulted in a clear risk reduction benefit but all posed threats to blood sufficiency or cost. Therefore, the blood safety risk was concluded to be tolerable without specific mitigations.
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Affiliation(s)
- Veronica C. Hoad
- Clinical Services and Research, Australian Red Cross Lifeblood, West Melbourne, VIC 3003, Australia
| | - Philip Kiely
- Clinical Services and Research, Australian Red Cross Lifeblood, West Melbourne, VIC 3003, Australia
| | - Clive R. Seed
- Clinical Services and Research, Australian Red Cross Lifeblood, West Melbourne, VIC 3003, Australia
| | - Elvina Viennet
- Clinical Services and Research, Australian Red Cross Lifeblood, West Melbourne, VIC 3003, Australia
- School of Biomedical Sciences, Queensland University of Technology, Kelvin Grove, QLD 4059, Australia
| | - Iain B. Gosbell
- Clinical Services and Research, Australian Red Cross Lifeblood, West Melbourne, VIC 3003, Australia
- School of Medicine, Western Sydney University, Penrith, NSW 2751, Australia
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Modelling Japanese encephalitis virus transmission dynamics and human exposure in a Cambodian rural multi-host system. PLoS Negl Trop Dis 2022; 16:e0010572. [PMID: 35816555 PMCID: PMC9302853 DOI: 10.1371/journal.pntd.0010572] [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: 05/12/2021] [Revised: 07/21/2022] [Accepted: 06/08/2022] [Indexed: 11/26/2022] Open
Abstract
Japanese encephalitis (JE) is a vector-borne zoonosis and the leading cause of human viral encephalitis in Asia. Its transmission cycle is usually described as involving wild birds as reservoirs and pigs as amplifying hosts. JE is endemic in Cambodia, where it circulates in areas with low pig densities (<70 pigs per km2), and could be maintained in a multi-host system composed of pigs, but also poultry as competent hosts, and dogs, cattle and humans as non-competent hosts. We used a mathematical model representing Japanese encephalitis virus (JEV) transmission in a traditional Cambodian village that we calibrated with field data collected in 3 districts of Kandal province, Cambodia. First, R0 calculations allowed us to assess the capacity of the epidemiological system to be invaded by JEV and sustain virus transmission in villages in the 3 districts, and we predicted human exposure at the epidemiological equilibrium, based on simulations. Changes in spatial density of livestock, in agricultural practices, and epizootics (e.g., African swine fever), can profoundly alter the composition of host communities, which could affect JEV transmission and its impact on human health. In a second step, we then used the model to analyse how host community composition affected R0 and the predicted human exposure. Lastly, we evaluated the potential use of dog JE seroprevalence as an indicator of human exposure to JEV. In the modeled villages, the calculated R0 ranged from 1.07 to 1.38. Once the equilibrium reached, predicted annual probability of human exposure ranged from 9% to 47%, and predicted average age at infection was low, between 2 and 11 years old, highlighting the risk of severe forms of JEV infection and the need to intensify child immunization. According to the model, increasing the proportion of competent hosts induced a decrease in age at infection. The simulations also showed that JEV could invade a multi-host system with no pigs, reinforcing the assumption of poultry acting as reservoirs. Finally, the annual human exposure probability appeared linearly correlated with dog seroprevalence, suggesting that in our specific study area, dog seroprevalence would be a good proxy for human exposure. Japanese encephalitis virus (JEV) is endemic in Cambodia and remains the most common cause of acute viral encephalitis, particularly in children and adolescents. The traditionally described cycle of JEV, involving wild birds as reservoirs, pigs as amplifying hosts and Culex mosquitoes as vectors is questioned, with increasing evidence of a more complex multi-host system involved in areas where densities of pigs are low. In Cambodia, the infection could be maintained in a multi-host system consisting of pigs and poultry as competent hosts, and dogs, cattle and humans as non-competent hosts. We defined a compartmental dynamic model of JEV transmission in a multi-host system representing a rural Cambodian village, to predict human exposure to JEV in the studied area, and to analyse how host community composition may affect human exposure and R0 value. Our theoretical approach showed that variations of the composition of the multi-host system may have an impact on human exposure to JEV, and thus on the disease burden in humans, especially in young children. Besides children vaccination in JEV endemic areas, a proper evaluation of the impact on human health is needed to target prevention actions and reduce JEV burden in Cambodia.
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The Emergence of Japanese Encephalitis Virus in Australia in 2022: Existing Knowledge of Mosquito Vectors. Viruses 2022; 14:v14061208. [PMID: 35746679 PMCID: PMC9231386 DOI: 10.3390/v14061208] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 05/31/2022] [Accepted: 05/31/2022] [Indexed: 12/10/2022] Open
Abstract
In early 2022, the Japanese encephalitis virus (JEV) was identified as the cause of stillborn and mummified piglets in pig farms in southeastern Australia. Human cases and additional pig farms with infected piglets were subsequently identified across a widespread area encompassing four states. To inform surveillance and control programs, we synthesized existing information on Australian vectors of JEV, much of which was generated in response to incursions of JEV into the northern state of Queensland between 1995 and 2005. Members of the Culex sitiens subgroup, particularly Culex annulirostris, should be considered the primary vectors of JEV in Australia, as they yielded >87% of field detections of JEV, were highly efficient laboratory vectors of the virus, readily fed on pigs and birds (the key amplifying hosts of the virus) when they were available, and are widespread and often occur in large populations. Three introduced species, Culex quinquefasciatus, Culex gelidus and Culex tritaeniorhynchus may also serve as vectors, but more information on their geographical distribution, abundance and bionomics in the Australian context is required. Mosquitoes from other genera, such as Aedes and Verrallina, whilst considered relatively poor vectors, could play a regional or supplemental role in transmission, especially facilitating vertical transmission as a virus overwintering mechanism. Additional factors that could impact JEV transmission, including mosquito survival, dispersal and genetics, are also discussed. Possible directions for investigation are provided, especially in the context of the virus emerging in a region with different mosquito fauna and environmental drivers than northern Australia.
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Chen T, Zhu S, Wei N, Zhao Z, Niu J, Si Y, Cao S, Ye J. Protective Immune Responses Induced by an mRNA-LNP Vaccine Encoding prM-E Proteins against Japanese Encephalitis Virus Infection. Viruses 2022; 14:1121. [PMID: 35746593 PMCID: PMC9227124 DOI: 10.3390/v14061121] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 02/01/2023] Open
Abstract
Japanese encephalitis virus (JEV) is an important zoonotic pathogen, which causes central nervous system symptoms in humans and reproductive disorders in swine. It has led to severe impacts on human health and the swine industry; however, there is no medicine available for treating yet. Therefore, vaccination is the best preventive measure for this disease. In the study, a modified mRNA vaccine expressing the prM and E proteins of the JEV P3 strain was manufactured, and a mouse model was used to assess its efficacy. The mRNA encoding prM and E proteins showed a high level of protein expression in vitro and were encapsulated into a lipid nanoparticle (LNP). Effective neutralizing antibodies and CD8+ T-lymphocytes-mediated immune responses were observed in vaccinated mice. Furthermore, the modified mRNA can protect mice from a lethal challenge with JEV and reduce neuroinflammation caused by JEV. This study provides a new option for the JE vaccine and lays a foundation for the subsequent development of a more efficient and safer JEV mRNA vaccine.
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Affiliation(s)
- Tao Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (T.C.); (S.Z.); (N.W.); (Z.Z.); (J.N.); (Y.S.)
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, China
| | - Shuo Zhu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (T.C.); (S.Z.); (N.W.); (Z.Z.); (J.N.); (Y.S.)
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, China
| | - Ning Wei
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (T.C.); (S.Z.); (N.W.); (Z.Z.); (J.N.); (Y.S.)
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, China
| | - Zikai Zhao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (T.C.); (S.Z.); (N.W.); (Z.Z.); (J.N.); (Y.S.)
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, China
| | - Junjun Niu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (T.C.); (S.Z.); (N.W.); (Z.Z.); (J.N.); (Y.S.)
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, China
| | - Youhui Si
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (T.C.); (S.Z.); (N.W.); (Z.Z.); (J.N.); (Y.S.)
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, China
| | - Shengbo Cao
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (T.C.); (S.Z.); (N.W.); (Z.Z.); (J.N.); (Y.S.)
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, China
| | - Jing Ye
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China; (T.C.); (S.Z.); (N.W.); (Z.Z.); (J.N.); (Y.S.)
- Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
- The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan 430070, China
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20
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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.
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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;
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21
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McLean RK, Graham SP. The pig as an amplifying host for new and emerging zoonotic viruses. One Health 2022; 14:100384. [PMID: 35392655 PMCID: PMC8975596 DOI: 10.1016/j.onehlt.2022.100384] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 12/23/2022] Open
Abstract
Pig production is a rapidly growing segment of the global livestock sector, especially in Asia and Africa. Expansion and intensification of pig production has resulted in significant changes to traditional pig husbandry practices leading to an environment conducive to increased emergence and spread of infectious diseases. These include a number of zoonotic viruses including influenza, Japanese encephalitis, Nipah and coronaviruses. Pigs are known to independently facilitate the creation of novel reassortant influenza A virus strains, capable of causing pandemics. Moreover, pigs play a role in the amplification of Japanese encephalitis virus, transmitted by mosquito vectors found in areas inhabited by over half the world's human population. Furthermore, pigs acted as an amplifying host in the first and still most severe outbreak of Nipah virus in Malaysia, that necessitated the culling over 1 million pigs. Finally, novel porcine coronaviruses are being discovered in high pig-density countries which have pandemic potential. In this review, we discuss the role that pigs play as intermediate/amplifying hosts for zoonotic viruses with pandemic potential and consider how multivalent vaccination of pigs could in turn safeguard human health.
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22
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Mishra C, Samelius G, Khanyari M, Srinivas PN, Low M, Esson C, Venkatachalam S, Johansson Ö. Increasing risks for emerging infectious diseases within a rapidly changing High Asia. AMBIO 2022; 51:494-507. [PMID: 34292521 PMCID: PMC8297435 DOI: 10.1007/s13280-021-01599-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 05/24/2021] [Accepted: 06/29/2021] [Indexed: 06/13/2023]
Abstract
The cold and arid mountains and plateaus of High Asia, inhabited by a relatively sparse human population, a high density of livestock, and wildlife such as the iconic snow leopard Panthera uncia, are usually considered low risk for disease outbreaks. However, based on current knowledge about drivers of disease emergence, we show that High Asia is rapidly developing conditions that favor increased emergence of infectious diseases and zoonoses. This is because of the existing prevalence of potentially serious pathogens in the system; intensifying environmental degradation; rapid changes in local ecological, socio-ecological, and socio-economic factors; and global risk intensifiers such as climate change and globalization. To better understand and manage the risks posed by diseases to humans, livestock, and wildlife, there is an urgent need for establishing a disease surveillance system and improving human and animal health care. Public health must be integrated with conservation programs, more ecologically sustainable development efforts and long-term disease surveillance.
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Affiliation(s)
- Charudutt Mishra
- Snow Leopard Trust, 4649 Sunnyside Avenue North, Seattle, USA
- Nature Conservation Foundation, 3076/5, IV Cross Gokulam Park, Mysore, India
| | - Gustaf Samelius
- Snow Leopard Trust, 4649 Sunnyside Avenue North, Seattle, USA
- Nordens Ark, Åby Säteri, 456 93 Hunnebostrand, Sweden
| | - Munib Khanyari
- Snow Leopard Trust, 4649 Sunnyside Avenue North, Seattle, USA
- Nature Conservation Foundation, 3076/5, IV Cross Gokulam Park, Mysore, India
- Interdisciplinary Center for Conservation Sciences, Oxford, University UK
- Department of Biological Sciences, University of Bristol, Bristol, UK
| | | | - Matthew Low
- Department of Ecology, Swedish University of Agricultural Sciences, 75007 Uppsala, Sweden
| | - Carol Esson
- 41 Walnut Close, Speewah, Queensland, 4881 Australia
| | - Suri Venkatachalam
- Snow Leopard Trust, 4649 Sunnyside Avenue North, Seattle, USA
- Nature Conservation Foundation, 3076/5, IV Cross Gokulam Park, Mysore, India
| | - Örjan Johansson
- Snow Leopard Trust, 4649 Sunnyside Avenue North, Seattle, USA
- Department of Ecology, Grimsö Wildlife Research Station, Swedish University of Agricultural Sciences, 73091 Riddarhyttan, Sweden
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23
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Effectiveness of Live-Attenuated Genotype III Japanese Encephalitis Viral Vaccine against Circulating Genotype I Viruses in Swine. Viruses 2022; 14:v14010114. [PMID: 35062317 PMCID: PMC8778556 DOI: 10.3390/v14010114] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/02/2022] [Accepted: 01/07/2022] [Indexed: 01/15/2023] Open
Abstract
Expansion of genotype I (GI) Japanese encephalitis viruses (JEV) has resulted in the replacement of the dominant genotype III (GIII) viruses, raising serious public health concerns for using GIII virus-derived vaccines to effectively control JEV epidemics. Therefore, this study used swine as the model to estimate the effectiveness of GIII live-attenuated vaccine against GI virus infection by comparing the incidence of stillbirth/abortion in gilts from vaccinated and non-vaccinated pig farms during the GI-circulation period. In total, 389 and 213 litters of gilts were recorded from four vaccinated and two non-vaccinated pig farms, respectively. All viruses detected in the aborted fetuses and mosquitoes belonged to the GI genotype during the study period. We thus estimated that the vaccine effectiveness of GIII live-attenuated vaccine against GI viruses in naive gilts based on the overall incidence of stillbirth/abortion and incidence of JEV-confirmed stillbirth/abortion was 65.5% (50.8–75.7%) and 74.7% (34.5–90.2%), respectively. In contrast to previous estimates, the GIII live-attenuated vaccine had an efficacy of 95.6% (68.3–99.4%) to prevent the incidence of stillbirth/abortion during the GIII-circulating period. These results indicate that the vaccine effectiveness of GIII live-attenuated JEV vaccine to prevent stillbirth/abortion caused by GI viruses is lower than that against GIII viruses.
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Mulvey P, Duong V, Boyer S, Burgess G, Williams DT, Dussart P, Horwood PF. The Ecology and Evolution of Japanese Encephalitis Virus. Pathogens 2021; 10:1534. [PMID: 34959489 PMCID: PMC8704921 DOI: 10.3390/pathogens10121534] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 11/16/2022] Open
Abstract
Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus mainly spread by Culex mosquitoes that currently has a geographic distribution across most of Southeast Asia and the Western Pacific. Infection with JEV can cause Japanese encephalitis (JE), a severe disease with a high mortality rate, which also results in ongoing sequalae in many survivors. The natural reservoir of JEV is ardeid wading birds, such as egrets and herons, but pigs commonly play an important role as an amplifying host during outbreaks in human populations. Other domestic animals and wildlife have been detected as hosts for JEV, but their role in the ecology and epidemiology of JEV is uncertain. Safe and effective JEV vaccines are available, but unfortunately, their use remains low in most endemic countries where they are most needed. Increased surveillance and diagnosis of JE is required as climate change and social disruption are likely to facilitate further geographical expansion of Culex vectors and JE risk areas.
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Affiliation(s)
- Peter Mulvey
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia;
| | - Veasna Duong
- Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 12201, Cambodia; (V.D.); (S.B.); (P.D.)
| | - Sebastien Boyer
- Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 12201, Cambodia; (V.D.); (S.B.); (P.D.)
| | - Graham Burgess
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville 4811, Australia;
| | - David T. Williams
- Australian Centre for Disease Preparedness, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Geelong 3220, Australia;
| | - Philippe Dussart
- Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 12201, Cambodia; (V.D.); (S.B.); (P.D.)
| | - Paul F. Horwood
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia;
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville 4811, Australia;
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25
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Adetunji SA, Smolensky D, Mitzel DN, Owens JL, Chitko-McKown CG, Cernicchiaro N, Noronha LE. In Vitro Infection Dynamics of Japanese Encephalitis Virus in Established Porcine Cell Lines. Pathogens 2021; 10:pathogens10111468. [PMID: 34832623 PMCID: PMC8618157 DOI: 10.3390/pathogens10111468] [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: 06/30/2021] [Revised: 10/16/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022] Open
Abstract
Japanese encephalitis virus (JEV) is a zoonotic mosquito-borne pathogen that regularly causes severe neurological disease in humans in Southeast Asia and the Western Pacific region. Pigs are one of the main amplifying hosts of JEV and play a central role in the virus transmission cycle. The objective of this study was to identify in vitro cell systems to investigate early effects of JEV infection including viral replication and host cell death. Here, we demonstrate the susceptibility of several porcine cell lines to the attenuated genotype III JEV strain SA14-14-2. Monolayers of porcine nasal turbinate (PT-K75), kidney (SK-RST), testis (ST), and monocyte-derived macrophage (CΔ2+) cells were infected with SA14-14-2 for up to five days at a multiplicity of infection (MOI) of 0.1. The hamster kidney cell line BHK-21, previously shown to be susceptible to SA14-14-2, was used as a positive control. Culture supernatants and cells were collected between 0 and 120 h post infection (hpi), and monolayers were observed for cytopathic effect (CPE) using brightfield microscopy. The number of infectious virus particles was quantified by plaque assay and cell viability was determined using trypan blue staining. An indirect immunofluorescence assay was used to detect the presence of JEV NS1 antigens in cells infected at 1 MOI. All four porcine cell lines demonstrated susceptibility to SA14-14-2 and produced infectious virus by 12 hpi. Virus titers peaked at 48 hpi in CΔ2+, BHK-21, and SK-RST cells, at 72 hpi in PT-K75, and at 120 hpi in ST cells. CPE was visible in infected CΔ2+ and BHK-21 cells, but not the other three cell lines. The proportion of viable cells, as measured by trypan blue exclusion, declined after 24 hpi in BHK-21 and 48 hpi in CΔ2+ cells, but did not substantially decline in SK-RST, PT-K75 or ST cells. At 48 hpi, JEV NS1 was detected in all infected cell lines by fluorescence microscopy. These findings demonstrate several porcine cell lines which have the potential to serve as useful research tools for investigating JEV infection dynamics and host cell mechanisms in a natural amplifying host species, such as pigs, in vitro.
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Affiliation(s)
- Shakirat A. Adetunji
- Center for Outcomes Research and Epidemiology, Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA; (S.A.A.); (N.C.)
| | - Dmitriy Smolensky
- Center for Grain and Animal Health Research, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS 66502, USA;
| | - Dana N. Mitzel
- National Bio and Agro-Defense Facility, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS 66502, USA; (D.N.M.); (J.L.O.)
| | - Jeana L. Owens
- National Bio and Agro-Defense Facility, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS 66502, USA; (D.N.M.); (J.L.O.)
| | - Carol G. Chitko-McKown
- Roman L. Hruska U.S. Meat Animal Research Center, Agricultural Research Service, United States Department of Agriculture, Clay Center, NE 68933, USA;
| | - Natalia Cernicchiaro
- Center for Outcomes Research and Epidemiology, Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA; (S.A.A.); (N.C.)
| | - Leela E. Noronha
- National Bio and Agro-Defense Facility, Agricultural Research Service, United States Department of Agriculture, Manhattan, KS 66502, USA; (D.N.M.); (J.L.O.)
- Correspondence:
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26
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Kardena IM, Adi AAAM, Astawa NM, O’Dea M, Laurence M, Sahibzada S, Bruce M. Japanese encephalitis in Bali, Indonesia: ecological and socio-cultural perspectives. Int J Vet Sci Med 2021; 9:31-43. [PMID: 34589543 PMCID: PMC8451599 DOI: 10.1080/23144599.2021.1975879] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 08/17/2021] [Accepted: 08/22/2021] [Indexed: 12/28/2022] Open
Abstract
The increasing number of cases of acute encephalitis syndrome, a key presenting clinical sign of Japanese encephalitis infection in humans, along with increasing laboratory confirmed cases in Bali over recent years have led to the Indonesian government developing a national program of vaccination against Japanese encephalitis virus. In order to inform multidisciplinary management, a review was conducted to assess Japanese encephalitis virus-related cases in humans and animals including their determinants and detection in vectors. Along with published literature, key data from local authorized officers in Bali have been used to convey the recent situation of the disease. Related surveys detected up to 92% of the local children had antibodies against the virus with the annual incidence estimated to be 7.1 per 100,000 children. Additionally, reports on young and adult cases of infection within international travellers infected in Bali were documented with both non-fatal and fatal outcomes. Further seroprevalence surveys detected up to 90% with antibodies to the virus in animal reservoirs. The detection of the virus in certain Culex mosquito species and high levels of seropositivity may be associated with greater risk of the virus transmission to the human population. It was also highlighted that local sociocultural practices for agriculture and livestock were potentially associated with the high density of the vector and the reservoirs, which then may lead to the risk of the disease transmission in the ecology of Bali.
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Affiliation(s)
- I Made Kardena
- Department of Biopathology, Faculty of Veterinary Medicine, Udayana University, Denpasar, Indonesia
- School of Veterinary Medicine, College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia
| | - Anak Agung Ayu Mirah Adi
- Department of Biopathology, Faculty of Veterinary Medicine, Udayana University, Denpasar, Indonesia
| | - Nyoman Mantik Astawa
- Department of Biopathology, Faculty of Veterinary Medicine, Udayana University, Denpasar, Indonesia
| | - Mark O’Dea
- Department of Primary Industries and Regional Development, Dpird Diagnostics and Laboratory Services, Sustainability and Biosecurity, South Perth, Western Australia
| | - Michael Laurence
- School of Veterinary Medicine, College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia
| | - Shafi Sahibzada
- School of Veterinary Medicine, College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia
| | - Mieghan Bruce
- School of Veterinary Medicine, College of Science, Health, Engineering and Education, Murdoch University, Perth, Western Australia
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Auerswald H, Maquart PO, Chevalier V, Boyer S. Mosquito Vector Competence for Japanese Encephalitis Virus. Viruses 2021; 13:v13061154. [PMID: 34208737 PMCID: PMC8234777 DOI: 10.3390/v13061154] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/02/2021] [Accepted: 06/02/2021] [Indexed: 12/30/2022] Open
Abstract
Japanese encephalitis virus (JEV) is a zoonotic pathogen mainly found in East and Southeast Asia and transmitted by mosquitoes. The objective of this review is to summarize the knowledge on the diversity of JEV mosquito vector species. Therefore, we systematically analyzed reports of JEV found in field-caught mosquitoes as well as experimental vector competence studies. Based on the investigated publications, we classified 14 species as confirmed vectors for JEV due to their documented experimental vector competence and evidence of JEV found in wild mosquitoes. Additionally, we identified 11 mosquito species, belonging to five genera, with an experimentally confirmed vector competence for JEV but lacking evidence on their JEV transmission capacity from field-caught mosquitoes. Our study highlights the diversity of confirmed and potential JEV vector species. We also emphasize the variety in the study design of vector competence investigations. To account for the diversity of the vector species and regional circumstances, JEV vector competence should be studied in the local context, using local mosquitoes with local virus strains under local climate conditions to achieve reliable data. In addition, harmonization of the design of vector competence experiments would lead to better comparable data, informing vector and disease control measures.
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Affiliation(s)
- Heidi Auerswald
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia
- Correspondence:
| | - Pierre-Olivier Maquart
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia; (P.-O.M.); (S.B.)
| | - Véronique Chevalier
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia;
- UMR ASTRE, CIRAD, INRA, Université de Montpellier, 34000 Montpellier, France
| | - Sebastien Boyer
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 120210, Cambodia; (P.-O.M.); (S.B.)
- Institut Pasteur, 75015 Paris, France
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28
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Boyer S, Durand B, Yean S, Brengues C, Maquart PO, Fontenille D, Chevalier V. Host-Feeding Preference and Diel Activity of Mosquito Vectors of the Japanese Encephalitis Virus in Rural Cambodia. Pathogens 2021; 10:pathogens10030376. [PMID: 33800999 PMCID: PMC8003966 DOI: 10.3390/pathogens10030376] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/11/2021] [Accepted: 03/11/2021] [Indexed: 12/22/2022] Open
Abstract
Japanese Encephalitis (JE) is the most important cause of human encephalitis in Southeast Asia, and this zoonosis is mainly transmitted from pigs to human by mosquitoes. A better understanding of the host-feeding preference of Japanese encephalitis virus (JEV) major vectors is crucial for identifying risk areas, defining bridge vector species and targeting adapted vector control strategies. To assess host-feeding preference of JE vectors in a rural Cambodian area where JE is known to circulate, in 2017, we implemented four sessions of mosquito trapping (March, June, September, December), during five consecutive nights, collecting four times a night (6 p.m. to 6 a.m.), and using five baited traps simultaneously, i.e., cow, chicken, pig, human, and a blank one for control. In addition, blood meals of 157 engorged females trapped at the same location were opportunistically analyzed with polymerase chain reaction (PCR), using cow, pig, human, and dog blood primers. More than 95% of the 36,709 trapped mosquitoes were potential JE vectors. These vectors were trapped in large numbers throughout the year, including during the dry season, and from 6 p.m. to 6 a.m. Despite the apparent host-feeding preference of Culex vishnui, Cx. gelidus, and Cx. tritaenhyorhincus for cows, statistical analysis suggested that the primary target of these three mosquito species were pigs. Dog blood was detected in eight mosquitoes of the 157 tested, showing that mosquitoes also bite dogs, and suggesting that dogs may be used as proxy of the risk for human to get infected by JE virus.
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Affiliation(s)
- Sébastien Boyer
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, Phnom Penh 12201, Cambodia; (S.Y.); (P.-O.M.); (D.F.)
- Correspondence:
| | - Benoit Durand
- Laboratory for Animal Health, Epidemiology Unit, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), University Paris-Est, 94701 Maisons-Alfort, France;
| | - Sony Yean
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, Phnom Penh 12201, Cambodia; (S.Y.); (P.-O.M.); (D.F.)
| | - Cécile Brengues
- MIVEGEC Unit, Institut de Recherche pour le Développement (IRD), Université de Montpellier, CNRS, BP 64501, 34394 Montpellier, France;
| | - Pierre-Olivier Maquart
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, Phnom Penh 12201, Cambodia; (S.Y.); (P.-O.M.); (D.F.)
| | - Didier Fontenille
- Medical and Veterinary Entomology Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, Phnom Penh 12201, Cambodia; (S.Y.); (P.-O.M.); (D.F.)
- MIVEGEC Unit, Institut de Recherche pour le Développement (IRD), Université de Montpellier, CNRS, BP 64501, 34394 Montpellier, France;
| | - Véronique Chevalier
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, 5 Boulevard Monivong, Phnom Penh 12201, Cambodia;
- International Center of Research in Agriculture for Development (CIRAD), UMR AS TRE, 34090 Montpellier, France
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29
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Lord JS. Changes in Rice and Livestock Production and the Potential Emergence of Japanese Encephalitis in Africa. Pathogens 2021; 10:pathogens10030294. [PMID: 33806470 PMCID: PMC8000791 DOI: 10.3390/pathogens10030294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/15/2021] [Accepted: 03/02/2021] [Indexed: 11/16/2022] Open
Abstract
The known distribution of Japanese encephalitis (JE) is limited to Asia and Australasia. However, autochthonous transmission of Japanese encephalitis virus was reported in Africa for the first time in 2016. Reasons for the current geographic restriction of JE and the circumstances that may permit emergence in non-endemic areas are not well known. Here, I assess potential changes in vector breeding habitat and livestock production in Africa that are conducive to JEV transmission, using open-source data available from the Food and Agriculture Organization between 1961 and 2019. For 16 of 57 countries in Africa, there was evidence of existing, or an increase in, conditions potentially suitable for JE emergence. This comprised the area used for rice production and the predicted proportion of blood meals on pigs. Angola, where autochthonous transmission was reported, was one of these 16 countries. Studies to better quantify the role of alternative hosts, including domestic birds in transmission in endemic regions, would help to determine the potential for emergence elsewhere. In Africa, surveillance programs for arboviruses should not rule out the possibility of Japanese encephalitis virus (JEV) circulation in areas with high pig or bird density coincident with Culicine breeding habitats.
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Affiliation(s)
- Jennifer S Lord
- Department of Vector Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
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Hameed M, Wahaab A, Nawaz M, Khan S, Nazir J, Liu K, Wei J, Ma Z. Potential Role of Birds in Japanese Encephalitis Virus Zoonotic Transmission and Genotype Shift. Viruses 2021; 13:357. [PMID: 33668224 PMCID: PMC7996159 DOI: 10.3390/v13030357] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/15/2021] [Accepted: 02/20/2021] [Indexed: 12/13/2022] Open
Abstract
Japanese encephalitis (JE) is a vaccine-preventable disease caused by the Japanese encephalitis virus (JEV), which is primarily prevalent in Asia. JEV is a Flavivirus, classified into a single serotype with five genetically distinct genotypes (I, II, III, IV, and V). JEV genotype III (GIII) had been the most dominant strain and caused numerous outbreaks in the JEV endemic countries until 1990. However, recent data shows the emergence of JEV genotype I (GI) as a dominant genotype and it is gradually displacing GIII. The exact mechanism of this genotype displacement is still unclear. The virus can replicate in mosquito vectors and vertebrate hosts to maintain its zoonotic life cycle; pigs and aquatic wading birds act as an amplifying/reservoir hosts, and the humans and equines are dead-end hosts. The important role of pigs as an amplifying host for the JEV is well known. However, the influence of other domestic animals, especially birds, that live in high abundance and close proximity to the human is not well studied. Here, we strive to briefly highlight the role of birds in the JEV zoonotic transmission, discovery of birds as a natural reservoirs and amplifying host for JEV, species of birds susceptible to the JEV infection, and the proposed effect of JEV on the poultry industry in the future, a perspective that has been neglected for a long time. We also discuss the recent in vitro and in vivo studies that show that the newly emerged GI viruses replicated more efficiently in bird-derived cells and ducklings/chicks than GIII, and an important role of birds in the JEV genotype shift from GIII to GI.
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Affiliation(s)
- Muddassar Hameed
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (A.W.); (M.N.); (S.K.); (K.L.)
| | - Abdul Wahaab
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (A.W.); (M.N.); (S.K.); (K.L.)
| | - Mohsin Nawaz
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (A.W.); (M.N.); (S.K.); (K.L.)
| | - Sawar Khan
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (A.W.); (M.N.); (S.K.); (K.L.)
| | - Jawad Nazir
- Vaccinologist/Head Virology, Tréidlia Biovet Pty Ltd. Units, Seven Hills, NSW 2147, Australia;
| | - Ke Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (A.W.); (M.N.); (S.K.); (K.L.)
| | - Jianchao Wei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (A.W.); (M.N.); (S.K.); (K.L.)
| | - Zhiyong Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (A.W.); (M.N.); (S.K.); (K.L.)
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31
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Immune responses and protective effects against Japanese encephalitis induced by a DNA vaccine encoding the prM/E proteins of the attenuated SA14-14-2 strain. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2020; 85:104443. [PMID: 32619637 PMCID: PMC7324926 DOI: 10.1016/j.meegid.2020.104443] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 06/20/2020] [Accepted: 06/23/2020] [Indexed: 01/21/2023]
Abstract
Japanese encephalitis virus (JEV) is the causal pathogen of Japanese encephalitis (JE), which has become a severe public health problem and is one of the most rapidly spreading mosquito-borne diseases worldwide. Currently, there is no specific treatment for JEV. A vaccine would be an effective measure for reducing morbidity and mortality. Although the live attenuated vaccine SA14-14-2 has been approved in some countries, it is still necessary to develop safer, more effective, and less costly vaccines. In this study, a DNA vaccine candidate, pV-SA14ME, expressing the prM/E proteins of SA14-14-2 was inoculated into BALB/c mice via intramuscular electroporation, and the immunogenicity and degree of protection were evaluated. We found that administration of 50 μg pV-SA14ME via electroporation via three immunizations could induce persistent humoral and cellular immune responses and effectively protect mice against lethal JEV challenge. This study provides a basis for the subsequent promotion and use of the vaccine and lays the foundation for its further use in swine and humans.
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Ladreyt H, Auerswald H, Tum S, Ken S, Heng L, In S, Lay S, Top C, Ly S, Duong V, Dussart P, Durand B, Chevalier V. Comparison of Japanese Encephalitis Force of Infection in Pigs, Poultry and Dogs in Cambodian Villages. Pathogens 2020; 9:pathogens9090719. [PMID: 32882890 PMCID: PMC7558861 DOI: 10.3390/pathogens9090719] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/25/2020] [Accepted: 08/28/2020] [Indexed: 12/22/2022] Open
Abstract
Japanese encephalitis virus (JEV) is the main cause of human viral encephalitis in Asia, with a mortality rate reaching 30%, mostly affecting children. The traditionally described cycle involving wild birds as reservoirs, pigs as amplifying hosts and Culex mosquitoes as vectors is questioned, with increasing evidence of a more complex multi-host system involved in areas where densities of pigs are low, such as in Cambodia. In 2018, we examined pigs, chickens, ducks and dogs from Kandal province, Cambodia, for antibody response against JEV by hemagglutination inhibition and virus neutralization assays. Forces of infection (FOI) for flaviviruses and JEV were estimated per species and per unit of body surface area (BSA). JEV seroprevalence reached 31% (95% CI: 23-41%) in pigs, 1% (95% CI: 0.1-3%) in chickens, 12% (95% CI: 7-19%) in ducks and 35% (95% CI: 28-42%) in dogs. Pigs were most likely to be infected (FOI: 0.09 per month), but the FOI was higher in ducks than in pigs for a given BSA (ratio of 0.13). Dogs had a lower FOI than ducks but a higher FOI than chickens (0.01 per month). For a given BSA, dogs were less likely to be infected than pigs (ratio of 1.9). In Cambodia, the virus may be circulating between multiple hosts. Dogs live in close contact with humans, and estimating their exposure to JEV infection could be a relevant indicator of the risk for humans to get infected, which is poorly known due to underdiagnosis. Understanding the JEV cycle and developing tools to quantify the exposure of humans is essential to adapt and support control measures for this vaccine-preventable disease.
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Affiliation(s)
- Héléna Ladreyt
- Epidemiology Unit, Laboratory for Animal Health, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), University Paris-Est, 14 rue Pierre et Marie Curie, 94700 Maisons-Alfort, France; (H.L.); (B.D.)
- International Center of Research in Agriculture for Development (CIRAD), UMR ASTRE, F-34090 Montpellier, France
| | - Heidi Auerswald
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, 5 Monivong Boulevard, P.O Box. 983, Phnom Penh 12201, Cambodia; (H.A.); (S.K.); (L.H.); (S.I.); (C.T.); (V.D.); (P.D.)
| | - Sothyra Tum
- National Animal Health and Production Research Institute, General Directorate for Animal Health and Production, Ministry of Agriculture, Forestry and Fisheries, Phnom Penh 12201, Cambodia;
| | - Sreymom Ken
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, 5 Monivong Boulevard, P.O Box. 983, Phnom Penh 12201, Cambodia; (H.A.); (S.K.); (L.H.); (S.I.); (C.T.); (V.D.); (P.D.)
| | - Leangyi Heng
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, 5 Monivong Boulevard, P.O Box. 983, Phnom Penh 12201, Cambodia; (H.A.); (S.K.); (L.H.); (S.I.); (C.T.); (V.D.); (P.D.)
| | - Saraden In
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, 5 Monivong Boulevard, P.O Box. 983, Phnom Penh 12201, Cambodia; (H.A.); (S.K.); (L.H.); (S.I.); (C.T.); (V.D.); (P.D.)
| | - Sokchea Lay
- Immunology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, 5 Monivong Boulevard, P.O Box. 983, Phnom Penh 12201, Cambodia;
| | - Chakriyouth Top
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, 5 Monivong Boulevard, P.O Box. 983, Phnom Penh 12201, Cambodia; (H.A.); (S.K.); (L.H.); (S.I.); (C.T.); (V.D.); (P.D.)
| | - Sowath Ly
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, 5 Monivong Boulevard, PO Box 983, Phnom Penh 12201, Cambodia;
| | - Veasna Duong
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, 5 Monivong Boulevard, P.O Box. 983, Phnom Penh 12201, Cambodia; (H.A.); (S.K.); (L.H.); (S.I.); (C.T.); (V.D.); (P.D.)
| | - Philippe Dussart
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, 5 Monivong Boulevard, P.O Box. 983, Phnom Penh 12201, Cambodia; (H.A.); (S.K.); (L.H.); (S.I.); (C.T.); (V.D.); (P.D.)
| | - Benoit Durand
- Epidemiology Unit, Laboratory for Animal Health, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), University Paris-Est, 14 rue Pierre et Marie Curie, 94700 Maisons-Alfort, France; (H.L.); (B.D.)
| | - Véronique Chevalier
- International Center of Research in Agriculture for Development (CIRAD), UMR ASTRE, F-34090 Montpellier, France
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, 5 Monivong Boulevard, PO Box 983, Phnom Penh 12201, Cambodia;
- International Center of Research in Agriculture for Development (CIRAD), UMR ASTRE, Phnom Penh 12201, Cambodia
- Correspondence:
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Xu Z, Li X, Xue J, Shen L, Zheng W, Yin S, Xu J. S-palmitoylation of swine interferon-inducible transmembrane protein is essential for its anti-JEV activity. Virology 2020; 548:82-92. [PMID: 32838949 PMCID: PMC7301829 DOI: 10.1016/j.virol.2020.06.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/04/2020] [Accepted: 06/06/2020] [Indexed: 12/16/2022]
Abstract
Japanese encephalitis virus (JEV) is an infectious pathogen spreading in a wide range of vertebrate species. Pigs are amplifying hosts of JEV and thought to be maintained in nature predominantly by avian-mosquito cycles. In the innate immune system, interferon-inducible transmembrane protein (IFITM) is a small transmembrane protein family and has been identified as the first line of defense against a broad range of RNA virus invasion. In this paper, we found that swine IFITM (sIFITM) could restrict the replication of both JEV vaccine strain and wild strain NJ-2008. The cysteine S-palmitoylation modification of sIFITM plays important roles in their anti-JEV effects and intracellular distributions. Our findings show the anti-JEV activities of swine interferon-inducible transmembrane proteins and broaden the antiviral spectrum of IFITM protein family. The preliminary exploration of S-palmitoylation modification of sIFITM may contribute to understanding of the antiviral molecular mechanism of sIFITM.
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Affiliation(s)
- Zhao Xu
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China
| | - Xiaoling Li
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China
| | - Jichu Xue
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China
| | - Lingyi Shen
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China
| | - Wenming Zheng
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China
| | - Sugai Yin
- Molecular Biology Laboratory Center, Henan University of Chinese Medicine, 156 Jinshui East Road, Zhengzhou, 450046, China
| | - Jun Xu
- College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou, 450002, China.
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Auerswald H, Ruget AS, Ladreyt H, In S, Mao S, Sorn S, Tum S, Duong V, Dussart P, Cappelle J, Chevalier V. Serological Evidence for Japanese Encephalitis and West Nile Virus Infections in Domestic Birds in Cambodia. Front Vet Sci 2020; 7:15. [PMID: 32064271 PMCID: PMC7000427 DOI: 10.3389/fvets.2020.00015] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 01/09/2020] [Indexed: 12/30/2022] Open
Abstract
Mosquito-borne flaviviruses with an enzootic transmission cycle like Japanese encephalitis virus (JEV) and West Nile virus (WNV) are a major public health concern. The circulation of JEV in Southeast Asia is well-documented, and the important role of pigs as amplification hosts for the virus is long known. The influence of other domestic animals especially poultry that lives in high abundance and close proximity to humans is not intensively analyzed. Another understudied field in Asia is the presence of the closely related WNV. Such analyses are difficult to perform due to the intense antigenic cross-reactivity between these viruses and the lack of suitable standardized serological assays. The main objective of this study was to assess the prevalence of JEV and WNV flaviviruses in domestic birds, detailed in chickens and ducks, in three different Cambodian provinces. We determined the flavivirus seroprevalence using an hemagglutination inhibition assay (HIA). Additionally, we investigated in positive samples the presence of JEV and WNV neutralizing antibodies (nAb) using foci reduction neutralization test (FRNT). We found 29% (180/620) of the investigated birds positive for flavivirus antibodies with an age-depended increase of the seroprevalence (OR = 1.04) and a higher prevalence in ducks compared to chicken (OR = 3.01). Within the flavivirus-positive birds, we found 43% (28/65) with nAb against JEV. We also observed the expected cross-reactivity between JEV and WNV, by identifying 18.5% double-positive birds that had higher titers of nAb than single-positive birds. Additionally, seven domestic birds (10.7%) showed only nAb against WNV and no nAb against JEV. Our study provides evidence for an intense JEV circulation in domestic birds in Cambodia, and the first serological evidence for WNV presence in Southeast Asia since decades. These findings mark the need for a re-definition of areas at risk for JEV and WNV transmission, and the need for further and intensified surveillance of mosquito-transmitted diseases in domestic animals.
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Affiliation(s)
- Heidi Auerswald
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh, Cambodia
| | - Anne-Sophie Ruget
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh, Cambodia.,Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), Unité Mixte de Recherche ASTRE, Montpellier, France
| | - Helena Ladreyt
- Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), Unité Mixte de Recherche ASTRE, Montpellier, France.,ASTRE, Université Montpellier, CIRAD, INRAE, Montpellier, France.,Epidemiology Unit, Laboratory for Animal Health, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), University Paris-Est, Maisons-Alfort, France
| | - Saraden In
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh, Cambodia
| | - Sokthearom Mao
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh, Cambodia
| | - San Sorn
- General Directorate for Animal Health and Production, Ministry of Agriculture, Forestry and Fisheries, Phnom Penh, Cambodia
| | - Sothyra Tum
- National Animal Health and Production Research Institute, General Directorate for Animal Health and Production, Ministry of Agriculture, Forestry and Fisheries, Phnom Penh, Cambodia
| | - Veasna Duong
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh, Cambodia
| | - Philippe Dussart
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh, Cambodia
| | - Julien Cappelle
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh, Cambodia.,Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), Unité Mixte de Recherche ASTRE, Montpellier, France.,ASTRE, Université Montpellier, CIRAD, INRAE, Montpellier, France.,UMR EpiA, INRAE, VetAgro Sup, Marcy lÉtoile, France
| | - Véronique Chevalier
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh, Cambodia.,Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), Unité Mixte de Recherche ASTRE, Montpellier, France.,ASTRE, Université Montpellier, CIRAD, INRAE, Montpellier, France
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