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Chang Y, Hartemink N, Byrne AW, Gormley E, McGrath G, Tratalos JA, Breslin P, More SJ, de Jong MCM. Inferring bovine tuberculosis transmission between cattle and badgers via the environment and risk mapping. Front Vet Sci 2023; 10:1233173. [PMID: 37841461 PMCID: PMC10572351 DOI: 10.3389/fvets.2023.1233173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/29/2023] [Indexed: 10/17/2023] Open
Abstract
Bovine tuberculosis (bTB), caused by Mycobacterium bovis, is one of the most challenging and persistent health issues in many countries worldwide. In several countries, bTB control is complicated due to the presence of wildlife reservoirs of infection, i.e. European badger (Meles meles) in Ireland and the UK, which can transmit infection to cattle. However, a quantitative understanding of the role of cattle and badgers in bTB transmission is elusive, especially where there is spatial variation in relative density between badgers and cattle. Moreover, as these two species have infrequent direct contact, environmental transmission is likely to play a role, but the quantitative importance of the environment has not been assessed. Therefore, the objective of this study is to better understand bTB transmission between cattle and badgers via the environment in a spatially explicit context and to identify high-risk areas. We developed an environmental transmission model that incorporates both within-herd/territory transmission and between-species transmission, with the latter facilitated by badger territories overlapping with herd areas. Model parameters such as transmission rate parameters and the decay rate parameter of M. bovis were estimated by maximum likelihood estimation using infection data from badgers and cattle collected during a 4-year badger vaccination trial. Our estimation showed that the environment can play an important role in the transmission of bTB, with a half-life of M. bovis in the environment of around 177 days. Based on the estimated transmission rate parameters, we calculate the basic reproduction ratio (R) within a herd, which reveals how relative badger density dictates transmission. In addition, we simulated transmission in each small local area to generate a first between-herd R map that identifies high-risk areas.
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Affiliation(s)
- You Chang
- Quantitative Veterinary Epidemiology Group, Wageningen University and Research Centre, Wageningen, Netherlands
| | - Nienke Hartemink
- Quantitative Veterinary Epidemiology Group, Wageningen University and Research Centre, Wageningen, Netherlands
- Biometris, Wageningen University and Research Centre, Wageningen, Netherlands
| | - Andrew W. Byrne
- One-Health and Welfare Scientific Support Unit, Department of Agriculture, Food and the Marine, National Disease Control Centre, Dublin, Ireland
| | - Eamonn Gormley
- Tuberculosis Diagnostics and Immunology Research Centre, School of Agriculture, Food Science, and Veterinary Medicine, College of Life Sciences, University College Dublin, Dublin, Ireland
| | - Guy McGrath
- Centre for Veterinary Epidemiology and Risk Analysis, School of Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - Jamie A. Tratalos
- Centre for Veterinary Epidemiology and Risk Analysis, School of Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - Philip Breslin
- Ruminant Animal Health Division, Department of Agriculture, Food and the Marine, Dublin, Ireland
| | - Simon J. More
- Centre for Veterinary Epidemiology and Risk Analysis, School of Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - Mart C. M. de Jong
- Quantitative Veterinary Epidemiology Group, Wageningen University and Research Centre, Wageningen, Netherlands
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Byrum JR, Waltari E, Janson O, Guo SM, Folkesson J, Chhun BB, Vinden J, Ivanov IE, Forst ML, Li H, Larson AG, Blackmon L, Liu Z, Wu W, Ahyong V, Tato CM, McCutcheon KM, Hoh R, Kelly JD, Martin JN, Peluso MJ, Henrich TJ, Deeks SG, Prakash M, Greenhouse B, Mehta SB, Pak JE. MultiSero: An Open-Source Multiplex-ELISA Platform for Measuring Antibody Responses to Infection. Pathogens 2023; 12:671. [PMID: 37242341 PMCID: PMC10221076 DOI: 10.3390/pathogens12050671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/24/2023] [Accepted: 04/27/2023] [Indexed: 05/28/2023] Open
Abstract
A multiplexed enzyme-linked immunosorbent assay (ELISA) that simultaneously measures antibody binding to multiple antigens can extend the impact of serosurveillance studies, particularly if the assay approaches the simplicity, robustness, and accuracy of a conventional single-antigen ELISA. Here, we report on the development of multiSero, an open-source multiplex ELISA platform for measuring antibody responses to viral infection. Our assay consists of three parts: (1) an ELISA against an array of proteins in a 96-well format; (2) automated imaging of each well of the ELISA array using an open-source plate reader; and (3) automated measurement of optical densities for each protein within the array using an open-source analysis pipeline. We validated the platform by comparing antibody binding to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) antigens in 217 human sera samples, showing high sensitivity (0.978), specificity (0.977), positive predictive value (0.978), and negative predictive value (0.977) for classifying seropositivity, a high correlation of multiSero determined antibody titers with commercially available SARS-CoV-2 antibody tests, and antigen-specific changes in antibody titer dynamics upon vaccination. The open-source format and accessibility of our multiSero platform can contribute to the adoption of multiplexed ELISA arrays for serosurveillance studies, for SARS-CoV-2 and other pathogens of significance.
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Affiliation(s)
- Janie R. Byrum
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
| | - Eric Waltari
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
| | - Owen Janson
- Division of HIV, Infectious Disease, and Global Medicine, University of California, San Francisco, CA 94143, USA
- EPPIcenter Program, University of California, San Francisco, CA 94143, USA
| | - Syuan-Ming Guo
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
| | - Jenny Folkesson
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
| | - Bryant B. Chhun
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
| | - Joanna Vinden
- Infectious Diseases and Immunity Graduate Program, University of California, Berkeley, CA 94720-3370, USA
| | - Ivan E. Ivanov
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
| | - Marcus L. Forst
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
- Department of Applied Physics, Stanford University, Stanford, CA 94305, USA
| | - Hongquan Li
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Adam G. Larson
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Lena Blackmon
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
| | - Ziwen Liu
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
| | - Wesley Wu
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
| | - Vida Ahyong
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
| | - Cristina M. Tato
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
| | | | - Rebecca Hoh
- Division of HIV, Infectious Disease, and Global Medicine, University of California, San Francisco, CA 94143, USA
| | - J. Daniel Kelly
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA 94158, USA
| | - Jeffrey N. Martin
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA 94158, USA
| | - Michael J. Peluso
- Division of HIV, Infectious Disease, and Global Medicine, University of California, San Francisco, CA 94143, USA
| | - Timothy J. Henrich
- Division of Experimental Medicine, University of California, San Francisco, CA 94110, USA
| | - Steven G. Deeks
- Division of HIV, Infectious Disease, and Global Medicine, University of California, San Francisco, CA 94143, USA
| | - Manu Prakash
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Bryan Greenhouse
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
- Division of HIV, Infectious Disease, and Global Medicine, University of California, San Francisco, CA 94143, USA
- EPPIcenter Program, University of California, San Francisco, CA 94143, USA
| | - Shalin B. Mehta
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
| | - John E. Pak
- Chan Zuckerberg Biohub—San Francisco, San Francisco, CA 94158, USA
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Byrum JR, Waltari E, Janson O, Guo SM, Folkesson J, Chhun BB, Vinden J, Ivanov IE, Forst ML, Li H, Larson AG, Wu W, Tato CM, McCutcheon KM, Peluso MJ, Henrich TJ, Deeks SG, Prakash M, Greenhouse B, Pak JE, Mehta SB. multiSero: open multiplex-ELISA platform for analyzing antibody responses to SARS-CoV-2 infection. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2021. [PMID: 34013298 PMCID: PMC8132273 DOI: 10.1101/2021.05.07.21249238] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Serology has provided valuable diagnostic and epidemiological data on antibody responses to SARS-CoV-2 in diverse patient cohorts. Deployment of high content, multiplex serology platforms across the world, including in low and medium income countries, can accelerate longitudinal epidemiological surveys. Here we report multiSero, an open platform to enable multiplex serology with up to 48 antigens in a 96-well format. The platform consists of three components: ELISA-array of printed proteins, a commercial or home-built plate reader, and modular python software for automated analysis (pysero). We validate the platform by comparing antibody titers against the SARS-CoV-2 Spike, receptor binding domain (RBD), and nucleocapsid (N) in 114 sera from COVID-19 positive individuals and 87 pre-pandemic COVID-19 negative sera. We report data with both a commercial plate reader and an inexpensive, open plate reader (nautilus). Receiver operating characteristic (ROC) analysis of classification with single antigens shows that Spike and RBD classify positive and negative sera with the highest sensitivity at a given specificity. The platform distinguished positive sera from negative sera when the reactivity of the sera was equivalent to the binding of 1 ng mL−1 RBD-specific monoclonal antibody. We developed normalization and classification methods to pool antibody responses from multiple antigens and multiple experiments. Our results demonstrate a performant and accessible pipeline for multiplexed ELISA ready for multiple applications, including serosurveillance, identification of viral proteins that elicit antibody responses, differential diagnosis of circulating pathogens, and immune responses to vaccines.
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Ashford RT, Anderson P, Waring L, Davé D, Smith F, Delahay RJ, Gormley E, Chambers MA, Sawyer J, Lesellier S. Evaluation of the Dual Path Platform (DPP) VetTB assay for the detection of Mycobacterium bovis infection in badgers. Prev Vet Med 2020; 180:105005. [PMID: 32473415 DOI: 10.1016/j.prevetmed.2020.105005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/25/2020] [Accepted: 04/11/2020] [Indexed: 12/01/2022]
Abstract
Bovine tuberculosis (bTB), caused by Mycobacterium bovis, represents a major animal health issue. In the United Kingdom and the Republic of Ireland, European badgers (Meles meles) have been shown to act as a reservoir of M. bovis infection, hindering the eradication of bTB in livestock. The availability of suitable diagnostic assays, particularly those that may be applied in a "trap-side" setting, would facilitate the implementation of a wider range of disease control strategies. Here we evaluate the Dual Path Platform (DPP) VetTB assay, a lateral-flow type test for detecting antibodies to M. bovis antigens (MPB83 and ESAT-6/CFP-10). Both serum and whole blood were evaluated as diagnostic samples. Additionally, two methods were evaluated for interpretation of test results (qualitative interpretation by eye and quantitative measurement using an optical reader). The antibody response to MPB83 detected by the DPP VetTB assay increased significantly following experimental M. bovis infection of badgers, whilst the response to ESAT-6/CFP-10 showed no significant change. In sera from TB-free captive and naturally M. bovis infected wild badgers the MPB83 response exhibited a sensitivity of 55 % by eye and quantitative reader (95 % CI: 40-71 and 38-71, respectively), with slightly lower specificity when read by eye (93 % compared to 98 %; 95 % CI: 85-100 and 90-100, respectively). In whole blood, the DPP VetTB assay MPB83 response exhibited a sensitivity of 65 % (95 % CI: 50-80) when interpreted by eye and 53 % (95 % CI: 36-69) using quantitative values, whilst the specificity was 94 % and 98 % respectively (95 % CI: 88-100 and 90-100). Comparison with contemporaneous diagnostic test results from putatively naturally infected and TB-free badgers demonstrated varying levels of agreement. Using sera from naturally M. bovis infected and TB-free badgers, with post mortem confirmation of disease status, the DPP VetTB assay exhibited a sensitivity of 60 % (95 % CI: 41-77) when interpreted using quantitative values (specificity 95 %; 95 % CI: 76-100), and 67 % (95 % CI: 50-84) when read by eye (specificity 95 %; 95 % CI: 86-100). Further work is required to robustly characterize the DPP VetTB assay's performance in a wider selection of samples, and in the practical and epidemiological contexts in which it may be applied.
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Affiliation(s)
- Roland T Ashford
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey, KT15 3NB, United Kingdom.
| | - Paul Anderson
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey, KT15 3NB, United Kingdom
| | - Laura Waring
- National Wildlife Management Centre, Animal and Plant Health Agency, Woodchester Park, Nympsfield, Gloucestershire, GL10 3UJ, United Kingdom
| | - Dipesh Davé
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey, KT15 3NB, United Kingdom
| | - Freya Smith
- National Wildlife Management Centre, Animal and Plant Health Agency, Woodchester Park, Nympsfield, Gloucestershire, GL10 3UJ, United Kingdom
| | - Richard J Delahay
- National Wildlife Management Centre, Animal and Plant Health Agency, Woodchester Park, Nympsfield, Gloucestershire, GL10 3UJ, United Kingdom
| | - Eamonn Gormley
- School of Veterinary Medicine, University College Dublin, Veterinary Science Centre, Belfield, Dublin 4, Ireland
| | - Mark A Chambers
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey, KT15 3NB, United Kingdom; Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom
| | - Jason Sawyer
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey, KT15 3NB, United Kingdom
| | - Sandrine Lesellier
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey, KT15 3NB, United Kingdom; Nancy Laboratory for Rabies and Wildlife, ANSES, CS 40009 54220, Malzéville, Nancy, France
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Martin SW, O'Keeffe J, Byrne AW, Rosen LE, White PW, McGrath G. Is moving from targeted culling to BCG-vaccination of badgers (Meles meles) associated with an unacceptable increased incidence of cattle herd tuberculosis in the Republic of Ireland? A practical non-inferiority wildlife intervention study in the Republic of Ireland (2011-2017). Prev Vet Med 2020; 179:105004. [PMID: 32361147 DOI: 10.1016/j.prevetmed.2020.105004] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 03/17/2020] [Accepted: 04/09/2020] [Indexed: 12/12/2022]
Abstract
Bovine tuberculosis (BTB) remains as a costly disease of cattle-herds in the Republic of Ireland (ROI). This persistence is partially attributable to the presence of M. bovis infection in a wildlife reservoir, the European badger (Meles meles). Thus, both area-wide and limited-area targeted-badger-culling have been part of the ROI-BTB control/eradication program to help reduce the future incidence of a cattle-herd BTB breakdown (i.e. a "new herd-level occurrence of BTB"). However, neither badger-culling practice can be sustained as a major component in the ongoing BTB eradication program in the ROI. Vaccination of badgers with Bacille Calmette-Guérin (BCG) has been proposed as an alternative to badger culling. Thus, in 2011, a five-year non-inferiority study was implemented in seven counties in the ROI. This study was designed to compare and contrast the cattle-herd-BTB-incidence in areas where intramuscular badger vaccination would be implemented versus the cattle-herd-BTB-incidence in the remaining area of the same county where targeted-badger-culling was maintained as the standard treatment response to probable badger-sourced BTB breakdowns. Our outcome of interest was a new cattle-herd-BTB-episode (breakdown) with a total of >2 standard skin-test (SICTT) reactors detected during the episode. Treatments (badger vaccination or targeted badger culling) were cluster allocated based on where the majority of the herd owner's land was located. To assess the impact of the two treatments, we compared the incidence-risk, of our defined outcome, for cattle herds in the area under vaccination to the outcome incidence-risk for cattle herds in the remainder of the same county after 4 and 5 years of having implemented badger vaccination. A random-effects logit model with adjustment for clustering by treatment, and statistical control of herd-type, herd-size and five-year prior-BTB-episode history was used for our analyses. Although not included in the logistic model, a relative badger density metric based on the annual number of badgers captured-per-sett-night of capturing effort was developed for each treatment area; this metric indicated that relative badger density was approximately 40 % higher in vaccination areas than in the targeted badger-culling areas during our study. Overall, our study results indicated that vaccination was not inferior to targeted badger-culling in four counties and badger vaccination was deemed to produce ambivalent results in one (County Cork North) of the seven study sites in the ROI. A post-study investigation, in County Galway, where vaccination was deemed inferior to target culling, revealed that widespread purchases of cattle from a nearby cattle mart, by herd owners in the vaccination-area, was associated with the increased herd and vaccination-area risk of BTB. No single "biasing hypothesis" was evident for the apparent vaccine inferiority in the second study site (County Monaghan) where vaccination was deemed inferior to targeted culling; hence no further investigations were conducted.
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Affiliation(s)
- S W Martin
- Department of Population Medicine, Veterinary College, University of Guelph, Guelph, ON, N1G2W1 Canada.
| | - J O'Keeffe
- Department of Agriculture, Food and the Marine, Kildare St., Dublin 2, Ireland
| | - A W Byrne
- Department of Agriculture, Food and the Marine, Kildare St., Dublin 2, Ireland; Veterinary Science Division, Bacteriology Branch, Agri-Food and Bio-Science Institute, Stormont, Stoney Road, Belfast. BT4 35D, UK; School of Biological Sciences, Queens University Belfast, Belfast, UK
| | - L E Rosen
- Transboundary Epidemiology Analytics, LLC, Fort Collins, Colorado, 80521 USA
| | - P W White
- Department of Agriculture, Food and the Marine, Kildare St., Dublin 2, Ireland; UCD Centre for Veterinary Epidemiology and Risk Analysis, UCD School of Veterinary Medicine, Dublin, Belfield, Dublin 4, Ireland
| | - G McGrath
- UCD Centre for Veterinary Epidemiology and Risk Analysis, UCD School of Veterinary Medicine, Dublin, Belfield, Dublin 4, Ireland
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More SJ. Can bovine TB be eradicated from the Republic of Ireland? Could this be achieved by 2030? Ir Vet J 2019; 72:3. [PMID: 31057791 PMCID: PMC6485114 DOI: 10.1186/s13620-019-0140-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 04/02/2019] [Indexed: 12/23/2022] Open
Abstract
Background There has been an ongoing decline in bovine tuberculosis (TB) in the Republic of Ireland, however, TB has yet to be eradicated. Further to a recent commitment by the Irish government to eradicate TB by 2030, this paper considers two questions, ‘Can bovine TB be eradicated from the Republic of Ireland?’ and ‘Could this be achieved by 2030?’, given current knowledge from research. Main body of the abstract Until very recently, Ireland has lacked key tools required for eradication. This gap has substantially been filled with the national roll-out of badger vaccination. Nonetheless, there is robust evidence, drawn from general national research, international experiences, and results of a recent modelling study, to suggest that all current strategies plus badger vaccination will not be sufficient to successfully eradicate TB from Ireland by 2030. We face a critical decision point in the programme, specifically the scope and intensity of control measures from this point forward. Adequate information is available, both from research and international experience, to indicate that these additional measures should broadly focus on adequately addressing TB risks from wildlife, implementing additional risk-based cattle controls, and enhancing industry engagement. These three areas are considered in some detail. Conclusion Based on current knowledge, it will not be possible to eradicate TB by 2030 with current control strategies plus national badger vaccination. Additional measures will be needed if Ireland is to eradicate TB within a reasonable time frame. Decisions made now will have long-term implications both in terms of time-to-eradication and cumulative programme costs.
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Affiliation(s)
- Simon J More
- Centre for Veterinary Epidemiology and Risk Analysis, UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin, D04 W6F6 Ireland
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Houtsma E, Clegg TA, Good M, More SJ. Further improvement in the control of bovine tuberculosis recurrence in Ireland. Vet Rec 2018; 183:622. [PMID: 30171099 PMCID: PMC6288696 DOI: 10.1136/vr.104642] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 08/01/2018] [Accepted: 08/09/2018] [Indexed: 12/04/2022]
Abstract
Ongoing objective assessment of national bovine tuberculosis (bTB) policy in Ireland is important to monitor efforts towards improved bTB control. The study objective was to investigate temporal trends in the risk of herd recurrence. The study included all herds derestricted following a bTB episode ending in 1998, 2008 or 2012. The respective ‘study periods’ were up to the end of 2001 for 1998-derestricted herds, to the end of 2011 for 2008-derestricted herds, and to the end of 2015 for 2012-derestricted herds. A multivariable Cox proportional-hazard model was developed to examine time to next restriction. The results from the model showed a continuing significant decreasing trend in herd recurrence of bTB in Ireland from 1998 until 2015: herds derestricted in 2008 were 0.75 (95 per cent CI 0.68 to 0.82) times as likely to develop a further restriction compared with 1998 herds, and herds derestricted in 2012 were 0.85 (95per cent CI 0.76 to 0.95) times as likely as 2008 herds. However, despite significant improvements, recurrence of bTB remains a concern, with 30.2 per cent (95 per cent CI 28.0 to 32.4 per cent) of herds derestricted in 2012 being re-restricted over the subsequent three years. Further work is needed to address the two key drivers of herd recurrence, namely residual infection and local reinfection.
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Affiliation(s)
- Erik Houtsma
- UCD Centre for Veterinary Epidemiology and Risk Analysis, UCD School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - Tracy Ann Clegg
- UCD Centre for Veterinary Epidemiology and Risk Analysis, UCD School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - Margaret Good
- UCD Centre for Veterinary Epidemiology and Risk Analysis, UCD School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - Simon J More
- UCD Centre for Veterinary Epidemiology and Risk Analysis, UCD School of Veterinary Medicine, University College Dublin, Dublin, Ireland
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8
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Quantification of Mycobacterium bovis transmission in a badger vaccine field trial. Prev Vet Med 2018; 149:29-37. [DOI: 10.1016/j.prevetmed.2017.10.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 10/18/2017] [Accepted: 10/20/2017] [Indexed: 11/17/2022]
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9
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Serological Analysis of Tuberculosis in Goats by Use of the Enferplex Caprine TB Multiplex Test. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:CVI.00518-16. [PMID: 27974399 DOI: 10.1128/cvi.00518-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 11/23/2016] [Indexed: 11/20/2022]
Abstract
Tuberculosis in goats is usually diagnosed clinically, at postmortem, or by a positive skin test. However, none of these approaches detects all infected animals. Serology offers an additional tool to identify infected animals missed by current tests. We describe the use of the Enferplex Caprine TB serology test to aid the management of a large dairy goat herd undergoing a tuberculosis breakdown. Initial skin and serology testing showed that IgG antibodies were present in both serum and milk from 100% of skin test-positive animals and in serum and milk from 77.8 and 95.4% of skin test-negative animals, respectively. A good correlation was observed between serum and milk antibody levels. The herd had been vaccinated against Mycobacterium avium subsp. paratuberculosis, but no direct serological cross-reactions were found. Subsequent skin testing revealed 13.7% positive animals, 64.9% of which were antibody positive, while 42.1% of skin test-negative animals were seropositive. Antibody responses remained high 1 month later (57.1% positive), and the herd was slaughtered. Postmortem analysis of 20 skin test-negative goats revealed visible lesions in 6 animals, all of which had antibodies to six Mycobacterium bovis antigens. The results provide indirect evidence that serology testing with serum or milk could be a useful tool in the diagnosis and management of tuberculosis in goats.
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More SJ, Good M. Understanding and managing bTB risk: perspectives from Ireland. Vet Microbiol 2015; 176:209-18. [PMID: 25724333 DOI: 10.1016/j.vetmic.2015.01.026] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 01/27/2015] [Accepted: 01/31/2015] [Indexed: 01/01/2023]
Abstract
There is substantial variation in herd risk for bovine tuberculosis (bTB) in Ireland, with most herds playing little to no role in the ongoing endemic. In infected areas, bTB persistence (affecting one or a group of herds) is a key feature of the infection. In this paper, we present our current understanding and management of bTB risk in Ireland, based on a detailed review of research and policy. There is close interaction between science and policy in Ireland, seeking both to understand and effectively manage bTB risk. Detailed research on bTB persistence is presented, including current understanding of the relative importance of different infection sources, which can include residual infection in cattle and/or re-infection, either from local sources or following cattle introduction. In recent years, there have been three primary drivers for policy change, including scientific advances, ongoing improvements to programme supports, and ongoing programme review. In this review, three key future programme challenges are identified. Although good progress is being made, eradication has not yet been achieved. Firstly, a key question concerns the additional effort that will be required, to move towards final eradication. Secondly, a percentage of non-infected animals are falsely positive to current testing methods. This is an ongoing challenge, given the imperfect specificity of test methods but will become more so, as the positive predictive value falls with reducing bTB prevalence. Finally, there is a need to re-engage with the farming community, so that they play a much greater role in programme ownership.
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Affiliation(s)
- Simon J More
- UCD Centre for Veterinary Epidemiology and Risk Analysis, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Margaret Good
- Department of Agriculture, Food and the Marine, Kildare St, Dublin 2, Ireland
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