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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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Suresh KP, Nayak A, Dhanze H, Bhavya AP, Shivamallu C, Achar RR, Silina E, Stupin V, Barman NN, Kumar SK, Syed A, Kollur SP, Shreevatsa B, Patil SS. Prevalence of Japanese encephalitis (JE) virus in mosquitoes and animals of the Asian continent: A systematic review and meta-analysis. J Infect Public Health 2022; 15:942-949. [PMID: 35914358 DOI: 10.1016/j.jiph.2022.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 07/08/2022] [Accepted: 07/21/2022] [Indexed: 10/16/2022] Open
Abstract
BACKGROUND Japanese encephalitis (JE) is a viral zoonotic disease that has been found in several countries of Asia and is responsible for high mortality and morbidity of men and animals in rural and sub-urban endemic areas due to the virus re-circulation among diverse hosts and vectors. The present study estimates the prevalence of the JE virus in the vector and animal population of the Asian continent using a systematic review and meta-analysis. METHODS The Cochran collaborators' Preferred Reporting Items for Systematic Reviews and Meta-Analysis [PRISMA] guidelines were used for systematic review and meta-analysis. The heterogeneity was observed in meta-regression analysis due to several factors including region, species, and different diagnostic assays used in various studies. Thus we did sensitivity and subgroup analysis. RESULTS The prevalence of the JE virus was calculated using a total sample size of 47,391. Subgroup analysis revealed the JE virus prevalence of 39% in the Southeast Asia region, followed by East Asia with 35% and South Asia with 15% prevalence. Hence, the overall pooled prevalence of the JE virus was 26% in the Asian continent. CONCLUSIONS The highest proportion of infection was found in pigs amongst all animals, reinforcing the fact that they can be used as sentinels to predict outbreaks in humans. The findings of this study will enable researchers and policymakers in better understanding the disease's spatial and temporal distribution, as well as in creating and implementing location-specific JE prevention and control measures.
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Affiliation(s)
| | - Akshata Nayak
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru, Karnataka, India
| | - Himani Dhanze
- ICAR-Indian Veterinary Research Institute, Bareilly, UP, India
| | - Anenahalli Panduranga Bhavya
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru, Karnataka, India
| | - Chandan Shivamallu
- Department of Biotechnology and Bioinformatics, School of Life Sciences, JSS Academy of Higher Education and Research, Mysore, Karnataka, India
| | - Raghu Ram Achar
- Division of Biochemistry, School of Life Sciences, JSS Academy of Higher Education and Research, Mysuru, India
| | - Ekaterina Silina
- Department of Surgery, N.I. Pirogov National Research Medical University (RNRMU), Moscow, Russia
| | - Victor Stupin
- Department of Surgery, N.I. Pirogov National Research Medical University (RNRMU), Moscow, Russia
| | - Nagendra Nath Barman
- Department of Microbiology, College of Veterinary Sciences (AAU), Guwahati, Assam, India
| | - Seethakempanahalli Kempanna Kumar
- Department of Ethnoveterinary Sciences and Practices, The University of Trans-Disciplinary Health Science and Technology, Jarakabandekaval, Yelahanka, Bengaluru, India
| | - Asad Syed
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Shiva Prasad Kollur
- Department of Sciences, Amrita School of Arts and Sciences, Amrita Vishwa Vidyapeetham, Mysuru Campus, Mysuru, Karnataka, India
| | - Bhargav Shreevatsa
- Department of Biotechnology and Bioinformatics, School of Life Sciences, JSS Academy of Higher Education and Research, Mysore, Karnataka, India
| | - Sharanagouda S Patil
- ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI), Bengaluru, Karnataka, India.
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Dhanze H, Hussain M, Mehta D, Kumar MS, Gandham R, Gupta M, Barua AG, Suresh KP, Singh B. Prevalence and risk factors associated with Japanese encephalitis virus infection in swine population of Assam, India. ASIAN PAC J TROP MED 2022. [DOI: 10.4103/1995-7645.359788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
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Henriksson E, Söderberg R, Ström Hallenberg G, Kroesna K, Ly S, Sear B, Unger F, Tum S, Nguyen-Viet H, Lindahl JF. Japanese Encephalitis in Small-Scale Pig Farming in Rural Cambodia: Pig Seroprevalence and Farmer Awareness. Pathogens 2021; 10:pathogens10050578. [PMID: 34068673 PMCID: PMC8150308 DOI: 10.3390/pathogens10050578] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 05/03/2021] [Accepted: 05/06/2021] [Indexed: 12/03/2022] Open
Abstract
Japanese encephalitis (JE) is endemic in Cambodia, but circulation of JE virus (JEV) among domestic pigs has previously only been studied in the southern part of the country. The main purpose of this study was to determine the seroprevalence of JEV antibodies in smallholder pigs held in rural areas of Kampong Thom, Preah Vihear, Ratanakiri, and Stung Treng provinces, northeastern Cambodia. Another purpose was to identify possible associations between serologic status and other factors, such as reproductive disorders, and to investigate the farmers’ knowledge of mosquito-borne diseases and use of preventive measures. In October 2019, 139 households were visited throughout the study area, and 242 pigs were sampled for blood. The sera were analysed with ELISA for JEV antibodies. Household representatives were interviewed, and data were recorded for each sampled pig. The apparent seroprevalence was 89.1% in pigs between 3 and 6 months of age, and 100% in pigs over 6 months of age. In total, 93.0% of the pigs tested positive. Province appeared to be the only factor significantly associated with serologic status (p < 0.001). Almost all (97.8%) respondents knew that mosquitos could transmit diseases, and 70.5% had heard of JE. However, only one respondent knew that JEV is transmitted to people through mosquito bites. Very few respondents knew that pigs can become infected with JEV, and no one knew that mosquitos transmit the virus. All families used some sort of mosquito protection for themselves, but only 15.1% protected their pigs from mosquito bites. The children were vaccinated against JE in 93 households, while adults only were vaccinated in eight households. The results suggest that JEV transmission is intense in northeastern Cambodia, and that people’s knowledge about the transmission route of JEV and the role of pigs in the transmission cycle is low. Fortunately, people are well aware of mosquito-borne diseases in general and use mosquito protection, and many children are vaccinated against JE. Nonetheless, it is important that national vaccination is continued, and that people—especially in rural areas where pigs are commonly kept—are educated on the ecology and transmission of JEV.
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Affiliation(s)
- Ellinor Henriksson
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden; (E.H.); (R.S.); (G.S.H.)
| | - Rebecca Söderberg
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden; (E.H.); (R.S.); (G.S.H.)
| | - Gunilla Ström Hallenberg
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden; (E.H.); (R.S.); (G.S.H.)
- Public Health Agency Sweden, 171 65 Stockholm, Sweden
| | - Kang Kroesna
- Faculty of Veterinary Medicine, Royal University of Agriculture, Phnom Penh 12201, Cambodia; (K.K.); (S.L.); (B.S.)
| | - Sokong Ly
- Faculty of Veterinary Medicine, Royal University of Agriculture, Phnom Penh 12201, Cambodia; (K.K.); (S.L.); (B.S.)
| | - Borin Sear
- Faculty of Veterinary Medicine, Royal University of Agriculture, Phnom Penh 12201, Cambodia; (K.K.); (S.L.); (B.S.)
| | - Fred Unger
- Animal and Human Health Program, International Livestock Research Institute, Hanoi 100 000, Vietnam; (F.U.); (H.N.-V.)
| | - Sothyra Tum
- National Animal Health and Production Research Institute, General Directorate of Animal Health and Production, Phnom Penh 12350, Cambodia;
| | - Hung Nguyen-Viet
- Animal and Human Health Program, International Livestock Research Institute, Hanoi 100 000, Vietnam; (F.U.); (H.N.-V.)
| | - Johanna F. Lindahl
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden; (E.H.); (R.S.); (G.S.H.)
- Animal and Human Health Program, International Livestock Research Institute, Hanoi 100 000, Vietnam; (F.U.); (H.N.-V.)
- Department of Medical Biochemistry and Microbiology, Uppsala University, 751 23 Uppsala, Sweden
- Correspondence:
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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: 7] [Impact Index Per Article: 1.8] [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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Lee HS, Bui VN, Nguyen HX, Bui AN, Hoang TD, Nguyen-Viet H, Grace Randolph D, Wieland B. Seroprevalences of multi-pathogen and description of farm movement in pigs in two provinces in Vietnam. BMC Vet Res 2020; 16:15. [PMID: 31937298 PMCID: PMC6958752 DOI: 10.1186/s12917-020-2236-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 01/08/2020] [Indexed: 11/12/2022] Open
Abstract
Background In Vietnam, lack of animal health information is considered a major challenge for pig production. The main objective of this study was to assess the seroprevalences of five pathogens [porcine circovirus type 2 (PCV2), porcine reproductive and respiratory syndrome virus (PRRSV), mycoplasma hyopneumoniae (M. hyo), Japanese encephalitis virus (JEV) and leptospirosis] and to better characterize the farm movements through a survey. Results A total of 600 samples were collected from 120 farms from Bac Giang and Nghe An. Among unvaccinated herds, the highest seroprevalence was found for JE with 73.81% (95% CI: 68.39–78.74) in Bac Giang and 53.51% (95% CI 47.68–59.27) in Nghe An. Seroprevalences for PCV2 and M.hyo were 49.43% (95% CI: 45.06–53.80) and 46.06% (95% CI: 41.48–50.69) among unvaccinated animals. Accumulative co-infections for JE (86.25%) showed the highest level followed by M. hyo (66.25%) and PCV2 (62.50%). Three co-infections with JE had the highest positive rate (28.75%) followed by four co-infections (25.0%). Medium farms had relatively higher herd prevalences for all pathogens, except from leptospirosis. Overall, farmers exported/imported their pigs at the most 1–2 times every 6 months. Some respondents (5% for exportation and 20% for importation) had moved pigs more than 6 times over the last 6 months. Conclusions Our study provided another pool of evidence that showed that PCV2, PRRS and H. hyo are endemic in pigs in Vietnam. Given the economic impacts of these pathogens elsewhere, the findings confirm the need for studies to evaluate the association between antibody response and clinical relevance as well as to assess the economic impact of co-infections at farm level. We also found that high seroprevalences of JE and leptospirosis were detected in pigs. From a pubic health point of view, it is crucial to raise public awareness especially for high risk occupations (mainly pig farm workers).
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Affiliation(s)
- Hu Suk Lee
- International Livestock Research Institute (ILRI), Room 301-302, B1 Building, Van Phuc Diplomatic Compound, 298 Kim Ma Street, Ba Dinh District, Hanoi, Vietnam.
| | - Vuong Nghia Bui
- National Institute of Veterinary Research, 86 Truong Chinh, Phuong Mai, Dong Da, Hanoi, Vietnam
| | - Huyen Xuan Nguyen
- National Institute of Veterinary Research, 86 Truong Chinh, Phuong Mai, Dong Da, Hanoi, Vietnam
| | - Anh Ngoc Bui
- National Institute of Veterinary Research, 86 Truong Chinh, Phuong Mai, Dong Da, Hanoi, Vietnam
| | - Trung Duc Hoang
- National Institute of Veterinary Research, 86 Truong Chinh, Phuong Mai, Dong Da, Hanoi, Vietnam
| | - Hung Nguyen-Viet
- International Livestock Research Institute (ILRI), Room 301-302, B1 Building, Van Phuc Diplomatic Compound, 298 Kim Ma Street, Ba Dinh District, Hanoi, Vietnam
| | | | - Barbara Wieland
- International Livestock Research Institute (ILRI), Addis Ababa, Ethiopia
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Kumar HBC, Dhanze H, Bhilegaonkar KN, Chakurkar EB, Kumar A, Yathish HM. Serological evidence of Japanese encephalitis virus infection in pigs in a low human incidence state, Goa, India. Prev Vet Med 2020; 175:104882. [PMID: 31945550 DOI: 10.1016/j.prevetmed.2020.104882] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 12/31/2019] [Accepted: 01/02/2020] [Indexed: 11/17/2022]
Abstract
Japanese encephalitis (JE) is a mosquito-borne zoonosis caused by Japanese encephalitis virus (JEV). It is a leading cause of encephalitis in humans especially children in Asia. Aquatic wading birds are the reservoirs and pigs serve as amplifying hosts for JEV. Humans and horses are dead-end hosts. JE is endemic in several states of India. Goa, a small state on the west coast of India, had witnessed JE outbreaks in the past and as on date human JE cases are reported sporadically. Although human JE cases are well documented in Goa, the status of JEV exposure of pigs has not been well documented. Hence the present study was undertaken with an objective of identifying JEV exposure in the pig population of Goa state in the light of declining human JE cases. To achieve the objective, between January 2017 and May 2019, serum samples from 666 pigs were screened using enzyme-linked immunosorbent assay (ELISA) for the detection of anti-JEV IgG. The apparent prevalence of anti-JEV IgG in pigs was found to be 7.1 % (95 % confidence interval 5.3 %-9.3 %) and true prevalence was 4.6 % (95 % confidence interval 2.7 %-7.1 %). The seroprevalence of JE recorded in pigs of Goa state was low compared to other endemic states in India, which may also be one of the reasons for the lower prevalence of human JE cases in Goa state. Univariate analysis revealed that the age of the pigs and district did not significantly influence the JE seroprevalence in pigs of Goa state. However, in multivariable logistic regression, the North Goa district was found to significantly (p = 0.017) influence the JE seroprevalence in pigs. The study identified that JEV is still circulating in the Goan pig population and hence constant vigil is required to monitor the intensity of JEV circulation in pigs. Besides forewarning possible human outbreaks in the locality, evidence of JEV exposure in pig population provides valuable data on the magnitude and extent of geographical spread.
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Affiliation(s)
- H B Chethan Kumar
- ICAR - Central Coastal Agricultural Research Institute, Old Goa, Goa, 403402, India.
| | - H Dhanze
- Division of Veterinary Public Health, ICAR - Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India.
| | - K N Bhilegaonkar
- Training and Education Centre, ICAR - Indian Veterinary Research Institute, Shivajinagar, Pune, Maharashtra, 411 005, India.
| | - E B Chakurkar
- ICAR - Central Coastal Agricultural Research Institute, Old Goa, Goa, 403402, India.
| | - A Kumar
- Division of Animal Science, Krishi Bhavan, Indian Council of Agricultural Research, New Delhi, 110 114, India.
| | - H M Yathish
- Department of Animal Genetics and Breeding, Veterinary College, KVAFSU, Hebbal, Bengaluru, 560 024, Karnataka, India.
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Ladreyt H, Durand B, Dussart P, Chevalier V. How Central Is the Domestic Pig in the Epidemiological Cycle of Japanese Encephalitis Virus? A Review of Scientific Evidence and Implications for Disease Control. Viruses 2019; 11:E949. [PMID: 31618959 PMCID: PMC6832429 DOI: 10.3390/v11100949] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/04/2019] [Accepted: 10/11/2019] [Indexed: 11/17/2022] Open
Abstract
Despite the existence of human vaccines, Japanese encephalitis (JE) remains the leading cause of human encephalitis in Asia. Pigs are described as the main amplifying host, but their role in JE epidemiology needs to be reassessed in order to identify and implement efficient control strategies, for both human and animal health. We aimed to provide a systematic review of publications linked to JE in swine, in terms of both individual and population characteristics of JE virus (JEV) infection and circulation, as well as observed epidemiological patterns. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement to select and analyze relevant articles from the Scopus database, 127 of which were included in the review. Pigs are central, but the implication of secondary hosts cannot be ruled out and should be further investigated. Although human vaccination cannot eradicate the virus, it is clearly the most important means of preventing human disease. However, a better understanding of the actual involvement of domestic pigs as well as other potential JEV hosts in different JEV epidemiological cycles and patterns could help to identify additional/complementary control measures, either by targeting pigs or not, and in some specific epidemiological contexts, contribute to reduce virus circulation and protect humans from JEV infection.
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Affiliation(s)
- Héléna Ladreyt
- Epidemiology Unit, Laboratory for Animal Health, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), University Paris-Est, 94700 Maisons-Alfort, France.
- Agricultural Research for Development (CIRAD), UMR ASTRE, F-34090 Montpellier, France.
| | - Benoit Durand
- Epidemiology Unit, Laboratory for Animal Health, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), University Paris-Est, 94700 Maisons-Alfort, France.
| | - Philippe Dussart
- Virology Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, PO Box 983, Phnom Penh 12201, Cambodia.
| | - Véronique Chevalier
- Agricultural Research for Development (CIRAD), UMR ASTRE, F-34090 Montpellier, France.
- Epidemiology and Public Health Unit, Institut Pasteur du Cambodge, Institut Pasteur International Network, PO Box 983, Phnom Penh 12201, Cambodia.
- Agricultural Research for Development (CIRAD), UMR ASTRE, Phnom Penh 12201, Cambodia.
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Lee HS, Thanh TL, Ly NK, Nguyen-Viet H, Thakur KK, Grace D. Seroprevalence of leptospirosis and Japanese encephalitis in swine in ten provinces of Vietnam. PLoS One 2019; 14:e0214701. [PMID: 31369564 PMCID: PMC6675114 DOI: 10.1371/journal.pone.0214701] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 07/18/2019] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Leptospirosis is an important zoonotic disease with a global distribution, affecting a wide range of mammalian animals and humans. Japanese encephalitis (JE) virus is the major vector-borne zoonotic disease in the Asia-Pacific region. The main objective of this study was to evaluate the seroprevalence of serovar-specific Leptospira and JE in swine from 10 provinces in Vietnam. METHODS Samples were initially collected for swine influenza surveillance from March to April 2017 at large-scale farms (with at least 50 sows and/or 250 fattening pigs) with pigs that tested positive for influenza in the previous surveillance period (2015-16). FINDINGS A total of 2,000 sera samples were analyzed from 10 provinces. Overall, the seroprevalence of leptospirosis was 21.05% (95% CI: 19.28-22.90) using a cut-off titer of ≥ 1:100. The apparent prevalence of JE was 73.45% (95% CI: 71.46-75.37) while the true prevalence was slightly higher (74.46%, 95% credible interval: 73.73-86.41). We found a relatively high presence of leptospirosis and JE in pigs kept on large farms. Prevalence was comparable with other studies suggesting opportunistic testing of samples collected for other surveillance purposes can be a valuable tool to better understand and prevent the potential transmission of these zoonotic diseases from pigs to people in Vietnam. CONCLUSION Our study provides evidence to veterinarians and animal health professionals for evidence-based practice such as diagnosis, vaccination and zoonotic control. Further investigation into the possible role of different domestic animals, wildlife species or environmental factors is needed to identify the potential risk factors and transmission routes in Vietnam.
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Affiliation(s)
- Hu Suk Lee
- International Livestock Research Institute, Hanoi, Vietnam
| | - To Long Thanh
- National Center for Veterinary Diagnosis, 15/78 Duong Giai Phong-Phuong Mai Dong Da Hanoi, Hanoi, Vietnam
| | - Nguyen Khanh Ly
- National Center for Veterinary Diagnosis, 15/78 Duong Giai Phong-Phuong Mai Dong Da Hanoi, Hanoi, Vietnam
| | | | - Krishna K Thakur
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada
| | - Delia Grace
- International Livestock Research Institute, Nairobi, Kenya
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Di Francesco J, Choeung R, Peng B, Pring L, Pang S, Duboz R, Ong S, Sorn S, Tarantola A, Fontenille D, Duong V, Dussart P, Chevalier V, Cappelle J. Comparison of the dynamics of Japanese encephalitis virus circulation in sentinel pigs between a rural and a peri-urban setting in Cambodia. PLoS Negl Trop Dis 2018; 12:e0006644. [PMID: 30138381 PMCID: PMC6107123 DOI: 10.1371/journal.pntd.0006644] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 06/28/2018] [Indexed: 11/18/2022] Open
Abstract
Japanese encephalitis is mainly considered a rural disease, but there is growing evidence of a peri-urban and urban transmission in several countries, including Cambodia. We, therefore, compared the epidemiologic dynamic of Japanese encephalitis between a rural and a peri-urban setting in Cambodia. We monitored two cohorts of 15 pigs and determined the force of infection-rate at which seronegative pigs become positive-in two study farms located in a peri-urban and rural area, respectively. We also studied the mosquito abundance and diversity in proximity of the pigs, as well as the host densities in both areas. All the pigs seroconverted before the age of 6 months. The force of infection was 0.061 per day (95% confidence interval = 0.034-0.098) in the peri-urban cohort and 0.069 per day (95% confidence interval = 0.047-0.099) in the rural cohort. Several differences in the epidemiologic dynamic of Japanese encephalitis between both study sites were highlighted. The later virus amplification in the rural cohort may be linked to the later waning of maternal antibodies, but also to the higher pig density in direct proximity of the studied pigs, which could have led to a dilution of mosquito bites at the farm level. The force of infection was almost identical in both the peri-urban and the rural farms studied, which shifts the classic epidemiologic cycle of the virus. This study is a first step in improving our understanding of Japanese encephalitis virus ecology in different environments with distinct landscapes, human and animal densities.
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Affiliation(s)
- Juliette Di Francesco
- Institut Pasteur du Cambodge, Epidemiology and Public Health Unit, Phnom Penh, Cambodia
- University of Calgary, Faculty of Veterinary Medicine, Department of Ecosystem and Public Health, Calgary, Canada
- * E-mail:
| | - Rithy Choeung
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - Borin Peng
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - Long Pring
- Royal University of Agriculture, Phnom Penh, Cambodia
| | - Senglong Pang
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - Raphaël Duboz
- Institut Pasteur du Cambodge, Epidemiology and Public Health Unit, Phnom Penh, Cambodia
- UMR ASTRE, CIRAD, INRA, Université de Montpellier, Montpellier, France
| | - Sivuth Ong
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - San Sorn
- Ministry of Agriculture, Forestry, and Fisheries, Department of Animal Health and Production, Phnom Penh, Cambodia
| | - Arnaud Tarantola
- Institut Pasteur du Cambodge, Epidemiology and Public Health Unit, Phnom Penh, Cambodia
| | | | - Veasna Duong
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - Philippe Dussart
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - Véronique Chevalier
- Institut Pasteur du Cambodge, Epidemiology and Public Health Unit, Phnom Penh, Cambodia
- UMR ASTRE, CIRAD, INRA, Université de Montpellier, Montpellier, France
| | - Julien Cappelle
- Institut Pasteur du Cambodge, Epidemiology and Public Health Unit, Phnom Penh, Cambodia
- UMR ASTRE, CIRAD, INRA, Université de Montpellier, Montpellier, France
- UMR EpiA, VetAgro Sup, INRA, Marcy l’étoile, France
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12
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How much does direct transmission between pigs contribute to Japanese Encephalitis virus circulation? A modelling approach in Cambodia. PLoS One 2018; 13:e0201209. [PMID: 30114197 PMCID: PMC6095498 DOI: 10.1371/journal.pone.0201209] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 07/10/2018] [Indexed: 11/27/2022] Open
Abstract
Japanese Encephalitis (JE) is the most important cause of human encephalitis throughout Asia and the Pacific. Although JE is a vector-borne disease, it has been demonstrated experimentally that transmission between pigs can occur through direct contact. Whether pig-to-pig transmission plays a role in the natural epidemiological cycle of JE remains unknown. To assess whether direct transmission between pigs may occur under field conditions, we built two mathematical models of JE transmission incorporating vector-borne transmission alone or a combination of vector-borne and direct transmission. We used Markov Chain Monte Carlo (MCMC) techniques to estimate the parameters of the models. We fitted the models to (i) two serological datasets collected longitudinally from two pig cohorts (C1 and C2) during two periods of four months on a farm on the outskirts of Phnom-Penh, Cambodia and to (ii) a cross-sectional (CS) serological survey dataset collected from 505 swine coming from eight different provinces of Cambodia. In both cases, the model incorporating both vector-borne and direct transmission better explained the data. We computed the value of the basic reproduction number R0 (2.93 for C1, 2.66 for C2 and 2.27 for CS), as well as the vector-borne reproduction number Rpv and the direct transmission reproduction number Rpp. We then determined the contribution of direct transmission on R0 (11.90% for C1, 11.62% for C2 and 7.51% for CS). According to our results, the existence of pig-to-pig transmission is consistent with our swine serological data. Thus, direct transmission may contribute to the epidemiological cycle of JE in Cambodia. These results need to be confirmed in other eco-climatic settings, in particular in temperate areas where pig-to-pig transmission may facilitate the persistence of JE virus (JEV) during cold seasons when there are no or few mosquitoes.
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13
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Duong V, Dussart P, Buchy P. Zika virus in Asia. Int J Infect Dis 2017; 54:121-128. [DOI: 10.1016/j.ijid.2016.11.420] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/26/2016] [Accepted: 11/29/2016] [Indexed: 11/28/2022] Open
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14
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Cappelle J, Duong V, Pring L, Kong L, Yakovleff M, Prasetyo DB, Peng B, Choeung R, Duboz R, Ong S, Sorn S, Dussart P, Tarantola A, Buchy P, Chevalier V. Intensive Circulation of Japanese Encephalitis Virus in Peri-urban Sentinel Pigs near Phnom Penh, Cambodia. PLoS Negl Trop Dis 2016; 10:e0005149. [PMID: 27926937 PMCID: PMC5142769 DOI: 10.1371/journal.pntd.0005149] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/31/2016] [Indexed: 11/18/2022] Open
Abstract
Despite the increased use of vaccination in several Asian countries, Japanese Encephalitis (JE) remains the most important cause of viral encephalitis in Asia in humans with an estimated 68,000 cases annually. Considered a rural disease occurring mainly in paddy-field dominated landscapes where pigs are amplifying hosts, JE may nevertheless circulate in a wider range of environment given the diversity of its potential hosts and vectors. The main objective of this study was to assess the intensity of JE transmission to pigs in a peri-urban environment in the outskirt of Phnom Penh, Cambodia. We estimated the force of JE infection in two cohorts of 15 sentinel pigs by fitting a generalised linear model on seroprevalence monitoring data observed during two four-month periods in 2014. Our results provide evidence for intensive circulation of JE virus in a periurban area near Phnom Penh, the capital and most populated city of Cambodia. Understanding JE virus transmission in different environments is important for planning JE virus control in the long term and is also an interesting model to study the complexity of vector-borne diseases. Collecting quantitative data such as the force of infection will help calibrate epidemiological model that can be used to better understand complex vector-borne disease epidemiological cycles.
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Affiliation(s)
- Julien Cappelle
- CIRAD-ES, UPR AGIRs, Montpellier, France
- Institut Pasteur du Cambodge, Epidemiology and Public Health Unit, Phnom Penh, Cambodia
| | - Veasna Duong
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - Long Pring
- Royal University of Agriculture, Phnom Penh, Cambodia
| | - Lida Kong
- Royal University of Agriculture, Phnom Penh, Cambodia
| | - Maud Yakovleff
- Institut Pasteur du Cambodge, Epidemiology and Public Health Unit, Phnom Penh, Cambodia
| | | | - Borin Peng
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - Rithy Choeung
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - Raphaël Duboz
- CIRAD-ES, UPR AGIRs, Montpellier, France
- Institut Pasteur du Cambodge, Epidemiology and Public Health Unit, Phnom Penh, Cambodia
| | - Sivuth Ong
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - San Sorn
- National Veterinary Research Institute, Phnom Penh, Cambodia
| | - Philippe Dussart
- Institut Pasteur du Cambodge, Virology Unit, Phnom Penh, Cambodia
| | - Arnaud Tarantola
- Institut Pasteur du Cambodge, Epidemiology and Public Health Unit, Phnom Penh, Cambodia
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15
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Pham TT, Meng S, Sun Y, Lv W, Bahl J. Inference of Japanese encephalitis virus ecological and evolutionary dynamics from passive and active virus surveillance. Virus Evol 2016; 2:vew009. [PMID: 27774302 PMCID: PMC4989885 DOI: 10.1093/ve/vew009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
A comprehensive monitoring strategy is vital for tracking the spread of mosquito-borne Japanese encephalitis virus (JEV), the leading cause of viral encephalitis in Asia. Virus detection consists of passive surveillance of primarily humans and swine, and/or active surveillance in mosquitoes, which may be a valuable proxy in providing insights into ecological processes underlying the spread and persistence of JEV. However, it has not been well characterized whether passive surveillance alone can capture the circulating genetic diversity to make reasonable inferences. Here, we develop phylogenetic models to infer JEV host changes, spatial diffusion patterns, and evolutionary dynamics from data collected through active and passive surveillance. We evaluate the feasibility of using JEV sequence data collected from mosquitoes to estimate the migration histories of genotypes GI and GIII. We show that divergence times estimated from this dataset were comparable to estimates from all available data. Increasing the amount of data collected from active surveillance improved time of most recent common ancestor estimates and reduced uncertainty. Phylogenetic estimates using all available data and only mosquito data from active surveillance produced similar results, showing that GI epidemics were widespread and diffused significantly faster between regions than GIII. In contrast, GIII outbreaks were highly structured and unlinked suggesting localized, unsampled infectious sources. Our results show that active surveillance of mosquitoes can sufficiently capture circulating genetic diversity of JEV to confidently estimate spatial and evolutionary patterns. While surveillance of other hosts could contribute to more detailed disease tracking and evaluation, comprehensive JEV surveillance programs should include systematic surveillance in mosquitoes to infer the most complete patterns for epidemiology, and risk assessment.
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Affiliation(s)
- Truc T Pham
- Center for Infectious Diseases, The University of Texas School of Public Health, Houston, TX, USA
| | - Shengli Meng
- Wuhan Institute of Biological Products, Wuhan, China
| | - Yan Sun
- Wuhan Institute for Neuroscience and Neuroengineering, South-Central University for Nationalities, Wuhan, China and
| | - Wenli Lv
- Wuhan Institute of Biological Products, Wuhan, China
| | - Justin Bahl
- Center for Infectious Diseases, The University of Texas School of Public Health, Houston, TX, USA,; Laboratory of Virus Evolution, Program in Emerging Infectious Diseases, Duke-NUS Graduate Medical School, Singapore, Singapore
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A novel immunochromatographic test applied to a serological survey of Japanese encephalitis virus on pig farms in Korea. PLoS One 2015; 10:e0127313. [PMID: 25992769 PMCID: PMC4439121 DOI: 10.1371/journal.pone.0127313] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 04/13/2015] [Indexed: 12/15/2022] Open
Abstract
Among vertebrate species, pigs are a major amplifying host of Japanese encephalitis virus (JEV) and measuring their seroconversion is a reliable indicator of virus activity. Traditionally, the hemagglutination inhibition test has been used for serological testing in pigs; however, it has several limitations and, thus, a more efficient and reliable replacement test is required. In this study, we developed a new immunochromatographic test for detecting antibodies to JEV in pig serum within 15 min. Specifically, the domain III region of the JEV envelope protein was successfully expressed in soluble form and used for developing the immunochromatographic test. The test was then applied to the surveillance of Japanese encephalitis (JE) in Korea. We found that our immunochromatographic test had good sensitivity (84.8%) and specificity (97.7%) when compared with an immunofluorescence assay used as a reference test. During the surveillance of JE in Korea in 2012, the new immunochromatographic test was used to test the sera of 1,926 slaughtered pigs from eight provinces, and 228 pigs (11.8%) were found to be JEV-positive. Based on these results, we also produced an activity map of JEV, which marked the locations of pig farms in Korea that tested positive for the virus. Thus, the immunochromatographic test reported here provides a convenient and effective tool for real-time monitoring of JEV activity in pigs.
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17
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Wang H, Liang G. Epidemiology of Japanese encephalitis: past, present, and future prospects. Ther Clin Risk Manag 2015; 11:435-48. [PMID: 25848290 PMCID: PMC4373597 DOI: 10.2147/tcrm.s51168] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Japanese encephalitis (JE) is one of severe viral encephalitis that affects individuals in Asia, western Pacific countries, and northern Australia. Although 67,900 JE cases have been estimated among 24 JE epidemic countries annually, only 10,426 have been reported in 2011. With the establishment of JE surveillance and vaccine use in some countries, the JE incidence rate has decreased; however, serious outbreaks still occur. Understanding JE epidemics and identifying the circulating JE virus genotypes will improve JE prevention and control. This review summarizes the current epidemiology data in these countries.
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Affiliation(s)
- Huanyu Wang
- State Key Laboratory for Infectious Disease Prevention and Control (SKLID), Department of Viral Encephalitis, Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing People's Republic of China ; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China
| | - Guodong Liang
- State Key Laboratory for Infectious Disease Prevention and Control (SKLID), Department of Viral Encephalitis, Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing People's Republic of China ; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China
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18
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Tarantola A, Goutard F, Newton P, de Lamballerie X, Lortholary O, Cappelle J, Buchy P. Estimating the burden of Japanese encephalitis virus and other encephalitides in countries of the mekong region. PLoS Negl Trop Dis 2014; 8:e2533. [PMID: 24498443 PMCID: PMC3907313 DOI: 10.1371/journal.pntd.0002533] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2013] [Accepted: 09/13/2013] [Indexed: 11/24/2022] Open
Abstract
Diverse aetiologies of viral and bacterial encephalitis are widely recognized as significant yet neglected public health issues in the Mekong region. A robust analysis of the corresponding health burden is lacking. We retrieved 75 articles on encephalitis in the region published in English or in French from 1965 through 2011. Review of available data demonstrated that they are sparse and often derived from hospital-based studies with significant recruitment bias. Almost half (35 of 75) of articles were on Japanese encephalitis virus (JEV) alone or associated with dengue. In the Western Pacific region the WHO reported 30,000-50,000 annual JEV cases (15,000 deaths) between 1966 and 1996 and 4,633 cases (200 deaths) in 2008, a decline likely related to the introduction of JEV vaccination in China, Vietnam, or Thailand since the 1980s. Data on dengue, scrub typhus and rabies encephalitis, among other aetiologies, are also reviewed and discussed. Countries of the Mekong region are undergoing profound demographic, economic and ecological change. As the epidemiological aspects of Japanese encephalitis (JE) are transformed by vaccination in some countries, highly integrated expert collaborative research and objective data are needed to identify and prioritize the human health, animal health and economic burden due to JE and other pathogens associated with encephalitides.
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Affiliation(s)
| | - Flavie Goutard
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia
- Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), Département ES, Unité AGIRs, Montpellier, France
| | - Paul Newton
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR and Centre for Tropical Medicine, Nuffield Department of Medicine, Churchill Hospital, University of Oxford, Oxford, United Kingdom
| | - Xavier de Lamballerie
- Aix Marseille University, IRD French Institute of Research for Development, EHESP French School of Public Health, UMR_D 190 “Emergence des Pathologies Virales”, Marseille, France
| | - Olivier Lortholary
- Université René Descartes, Hôpital Necker-Enfants malades, Centre d'Infectiologie Necker Pasteur, IHU Imagine, Labex IBEID, Paris, France
| | - Julien Cappelle
- Institut Pasteur du Cambodge, Phnom Penh, Cambodia
- Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), Département ES, Unité AGIRs, Montpellier, France
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Abstract
Zoonoses are an issue of growing interest in South-East Asia, where environmental factors and socio-economic context favor the endemization of well-known diseases and the emergence of new pathogens at the human-wildlife interface. However, the health status of the region with respect to many zoonotic diseases remains poorly defined, despite the high overall burden of zoonoses on the countries of the area, and the global risk of new biological threats in the region. The first objective of this paper was to provide an update of data on the zoonoses commonly described by the scientific community and reported by governmental institutions and international organizations in continental South-East Asia. The analysis of the available data led to the identification of some trends in the evolution of the diseases, as well as some gaps in knowledge and in the current surveillance and control networks. In light of these findings, we discuss measures for effectively addressing zoonotic disease issues in South-East Asia, such as the allocation of funds for research and for surveillance and control programs, and a multi-sectoral and multi-disciplinary approach at various levels.
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Rith S, Netrabukkana P, Sorn S, Mumford E, Mey C, Holl D, Goutard F, Y B, Fenwick S, Robertson I, Roger F, Buchy P. Serologic evidence of human influenza virus infections in swine populations, Cambodia. Influenza Other Respir Viruses 2012; 7:271-9. [PMID: 22642704 PMCID: PMC5779822 DOI: 10.1111/j.1750-2659.2012.00382.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background This study was conducted from 2006 to 2010 and investigated the seroprevalence of influenza A viruses in Cambodian pigs, including human H1N1, H3N2, 2009 pandemic H1N1 (A(H1N1)pdm09), and highly pathogenic avian H5N1 influenza A viruses. Methods A total of 1147 sera obtained from pigs in Cambodia were tested by haemagglutination inhibition (HI) assays for antibody to human influenza A viruses along with both HI and microneutralization (MN) tests to assess immunological responses to H5N1 virus. The results were compared by year, age, and province. Results Antibodies against a human influenza A virus were detected in 14·9% of samples. A(H1N1)pdm09 virus were dominant over the study period (23·1%), followed by those to human H1N1 (17·3%) and H3N2 subtypes (9·9%). No pigs were serologically positive for avian H5 influenza viruses. The seroprevalence of human H1N1 and H3N2 influenza viruses peaked in 2008, while that of A(H1N1)pdm09 reached a peak in 2010. No significant differences in seroprevalence to human influenza subtypes were observed in different age groups. Conclusions Cambodian pigs were exposed to human strains of influenza A viruses either prior to or during this study. The implications of these high prevalence rates imply human‐to‐swine influenza virus transmission in Cambodia. Although pigs are mostly raised in small non‐commercial farms, our preliminary results provide evidence of sustained human influenza virus circulation in pig populations in Cambodia.
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Affiliation(s)
- Sareth Rith
- Institut Pasteur in Cambodia, Virology Unit, Réseau International des Instituts Pasteur, Phnom Penh, Cambodia
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21
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Yang DK, Kim HH, Hyun BH, Lim SI, Nam YK, Nah JJ, Song JY. Detection of Neutralizing Antibody Against Japanese Encephalitis Virus in Wild Boars of Korea. ACTA ACUST UNITED AC 2012. [DOI: 10.4167/jbv.2012.42.4.353] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Dong-Kun Yang
- Animal, Plant and Fishery Quarantine Inspection Agency, MIFAFF, Anyang, Korea
| | - Ha-Hyun Kim
- Animal, Plant and Fishery Quarantine Inspection Agency, MIFAFF, Anyang, Korea
| | - Bang-Hun Hyun
- Animal, Plant and Fishery Quarantine Inspection Agency, MIFAFF, Anyang, Korea
| | - Seong-In Lim
- Animal, Plant and Fishery Quarantine Inspection Agency, MIFAFF, Anyang, Korea
| | - Yun-Kyoung Nam
- College of Veterinary Medicine, JeonBuk National University, JeonJu, Korea
| | - Jin-Ju Nah
- Animal, Plant and Fishery Quarantine Inspection Agency, MIFAFF, Anyang, Korea
| | - Jae-Young Song
- Animal, Plant and Fishery Quarantine Inspection Agency, MIFAFF, Anyang, Korea
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