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Ahmad I, Raji YE, Hassan L, Samaila A, Aliyu B, Zinsstag J, Fasina FO. Systematic review and meta-analysis of tuberculosis in animals in Nigeria. Heliyon 2023; 9:e17215. [PMID: 37383186 PMCID: PMC10293676 DOI: 10.1016/j.heliyon.2023.e17215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 06/07/2023] [Accepted: 06/09/2023] [Indexed: 06/30/2023] Open
Abstract
Animal tuberculosis (TB) is a contagious and chronic disease caused by mycobacteria belonging to theMycobacterium tuberculosis complex (MTBC) in domestic and wild animals. MTBC strains infection has been confirmed in many animal species in Nigeria, including captive wildlife, cattle, dromedary camels, goats, and pigs. Despite widespread infection and the potential impact of the disease on public health, active surveillance and control strategies are absent in Nigeria. This study aimed to conduct the first comprehensive meta-analysis to assess the distribution of tuberculosis and analyze the potential moderators of infection in animals in Nigeria. Eligible studies (sixty-one (Cadmus et al., 2014) [61] prevalence and seven (Menzies and Neill, 2000) [7] case reports) were retrieved and included in the analysis. The analyses showed an overall pooled TB prevalence of 7.0% (95% CI: 6.0-8.0) comprising of infection distributed in cattle (8.0%, 95% CI: 7.0-8.0), goats (0.47%, 95% CI: 0-1.2), sheep (0.27%, 95% CI: 0.14-0.46), camels (13.0%, 95% CI: 0-47), and wildlife (13.0%, 95% CI: 9-16) respectively. The occurrence of infection was significantly moderated by the publication periods, geographical location, sample size, and detection methods. TB prevalence was heterogeneous across several predictors, with the year of publication exhibiting a higher rate (46%) of the detected heterogeneity. These findings should provide policy-relevant information to guide the design and establishment of prevention and control measures amenable to the local situations in Nigeria.
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Affiliation(s)
- Ibrahim Ahmad
- Animal Health and Livestock Development, Gusau, Zamfara, Nigeria
- Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, UPM, 43400, Serdang, Selangor, Malaysia
| | - Yakubu Egigogo Raji
- Department of Pathology, Clinical Microbiology Unit, College of Health Sciences Ibrahim Badamasi Babangida University, Lapai, Nigeria
| | - Latiffah Hassan
- Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, UPM, 43400, Serdang, Selangor, Malaysia
| | - Abdullahi Samaila
- Department of Pharmacology, College of Medical Sciences, Umaru Musa Yar'adua University, Katsina, Nigeria
| | - Basiru Aliyu
- Department of Microbiology, Federal University Birnin Kebbi, Kebbi, Nigeria
| | - Jakob Zinsstag
- Human and Animal Health Unit, Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, PO Box, 4002, Basel, Switzerland
| | - Folorunso O. Fasina
- Emergency Centre for Transboundary Animal Diseases (ECTAD), Food and Agriculture Organization of the United Nations (FAO), United Nations Office in Nairobi, 00100, Kenya
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort, 0110, South Africa
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2
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Remot A, Carreras F, Coupé A, Doz-Deblauwe É, Boschiroli ML, Browne JA, Marquant Q, Descamps D, Archer F, Aseffa A, Germon P, Gordon SV, Winter N. Mycobacterial Infection of Precision-Cut Lung Slices Reveals Type 1 Interferon Pathway Is Locally Induced by Mycobacterium bovis but Not M. tuberculosis in a Cattle Breed. Front Vet Sci 2021; 8:696525. [PMID: 34307535 PMCID: PMC8299756 DOI: 10.3389/fvets.2021.696525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 06/02/2021] [Indexed: 11/13/2022] Open
Abstract
Tuberculosis exacts a terrible toll on human and animal health. While Mycobacterium tuberculosis (Mtb) is restricted to humans, Mycobacterium bovis (Mb) is present in a large range of mammalian hosts. In cattle, bovine TB (bTB) is a noticeable disease responsible for important economic losses in developed countries and underestimated zoonosis in the developing world. Early interactions that take place between mycobacteria and the lung tissue early after aerosol infection govern the outcome of the disease. In cattle, these early steps remain poorly characterized. The precision-cut lung slice (PCLS) model preserves the structure and cell diversity of the lung. We developed this model in cattle in order to study the early lung response to mycobacterial infection. In situ imaging of PCLS infected with fluorescent Mb revealed bacilli in the alveolar compartment, in adjacent or inside alveolar macrophages, and in close contact with pneumocytes. We analyzed the global transcriptional lung inflammation signature following infection of PCLS with Mb and Mtb in two French beef breeds: Blonde d'Aquitaine and Charolaise. Whereas, lungs from the Blonde d'Aquitaine produced high levels of mediators of neutrophil and monocyte recruitment in response to infection, such signatures were not observed in the Charolaise in our study. In the Blonde d'Aquitaine lung, whereas the inflammatory response was highly induced by two Mb strains, AF2122 isolated from cattle in the UK and Mb3601 circulating in France, the response against two Mtb strains, H37Rv, the reference laboratory strain, and BTB1558, isolated from zebu in Ethiopia, was very low. Strikingly, the type I interferon pathway was only induced by Mb but not Mtb strains, indicating that this pathway may be involved in mycobacterial virulence and host tropism. Hence, the PCLS model in cattle is a valuable tool to deepen our understanding of early interactions between lung host cells and mycobacteria. It revealed striking differences between cattle breeds and mycobacterial strains. This model could help in deciphering biomarkers of resistance vs. susceptibility to bTB in cattle as such information is still critically needed for bovine genetic selection programs and would greatly help the global effort to eradicate bTB.
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Affiliation(s)
- Aude Remot
- INRAE, Université de Tours, Nouzilly, France
| | | | | | | | - Maria L Boschiroli
- Paris-Est University, National Reference Laboratory for Tuberculosis, Animal Health Laboratory, Anses, Maisons-Alfort, France
| | - John A Browne
- UCD School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | | | | | - Fabienne Archer
- INRAE, UMR754, Viral Infections and Comparative Pathology, IVPC, Univ Lyon, Université Claude Bernard Lyon 1, EPHE, Lyon, France
| | - Abraham Aseffa
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | | | - Stephen V Gordon
- UCD School of Veterinary Medicine and UCD Conway Institute, University College Dublin, Dublin, Ireland
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3
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Xu F, Tian L, Li Y, Zhang X, Qi Y, Jing Z, Pan Y, Zhang L, Fan X, Wang M, Zeng Q, Fan W. High prevalence of extrapulmonary tuberculosis in dairy farms: Evidence for possible gastrointestinal transmission. PLoS One 2021; 16:e0249341. [PMID: 33784364 PMCID: PMC8009431 DOI: 10.1371/journal.pone.0249341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Accepted: 03/16/2021] [Indexed: 11/19/2022] Open
Abstract
Bovine tuberculosis (bTB) caused by Mycobacterium bovis (M. bovis) represents one of major zoonotic diseases among cattle, it also affects the health of human, other domestic animals and wild life populations. Inhalation of infected aerosol droplets is considered as the most frequent route of the infection. This study aims to investigate the current forms of tuberculosis in cattle and identify the possible transmission modes in dairy farms of China. 13,345 cows from eight dairy farms in three provinces were comprehensively diagnosed by a multitude of assays, including SIT, CIT, IFN-γ assay and ELISA. It has been indicated that advanced infection of bTB was found in 752 (5.64%) cattle, suggesting a high prevalence of tuberculosis in these dairy farms. In the necropsy examination of 151 positive cattle, typical bTB lesions were observed in 131 cattle (86.75%), of which, notably, 90.84% lesions appeared in liver, spleen, mesenteric lymph nodes, mammary lymph nodes and other organs, taking up a large proportion among cattle with advanced bTB infection. 71.26% extrapulmonary tuberculosis (EPTB) was related to gastrointestinal system. M. bovis nucleic acid was further found in milk and feces samples and M. bovis was even isolated from milk samples. Phylogenetic analysis based on whole genome sequencing unraveled that six isolates were closely related to M. bovis AF2122/97 originated from UK, whereas four isolates shared close relation to M. bovis 30 from China, respectively. Our data demonstrate that the increase of EPTB transmitted by digestive tract is implicated in the current high prevalence rate of bTB in China, which also provides leads for bTB control in other countries with high prevalence of bTB in the future.
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Affiliation(s)
- Fang Xu
- College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, Gansu, China
- National Animal Tuberculosis Reference Laboratory, Division of Zoonoses Surveillance, China Animal Health and Epidemiology Center, Qingdao, Shandong, China
| | - Lili Tian
- National Animal Tuberculosis Reference Laboratory, Division of Zoonoses Surveillance, China Animal Health and Epidemiology Center, Qingdao, Shandong, China
| | - Yan Li
- Animal Husbandry and Veterinary Station, Xinjiang Production and Construction Corps, Urumqi, Xinjiang, China
| | - Xuelian Zhang
- State Key Laboratory of Genetic Engineering, School of Life Science, Fudan University, Shanghai, China
| | - Yayin Qi
- College of Animal Science and Technology, Shihezi University, Shihezi, Xinjiang, China
| | - Zhigang Jing
- National Animal Tuberculosis Reference Laboratory, Division of Zoonoses Surveillance, China Animal Health and Epidemiology Center, Qingdao, Shandong, China
| | - Yangyang Pan
- College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, Gansu, China
| | - Li Zhang
- Animal Husbandry and Veterinary Station, Xinjiang Production and Construction Corps, Urumqi, Xinjiang, China
| | - Xiaoxu Fan
- National Animal Tuberculosis Reference Laboratory, Division of Zoonoses Surveillance, China Animal Health and Epidemiology Center, Qingdao, Shandong, China
| | - Meng Wang
- College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, Gansu, China
| | - Qiaoying Zeng
- College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, Gansu, China
| | - Weixing Fan
- National Animal Tuberculosis Reference Laboratory, Division of Zoonoses Surveillance, China Animal Health and Epidemiology Center, Qingdao, Shandong, China
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4
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Islam MN, Khan MK, Khan MFR, Kostoulas P, Rahman AKMA, Alam MM. Risk factors and true prevalence of bovine tuberculosis in Bangladesh. PLoS One 2021; 16:e0247838. [PMID: 33635911 PMCID: PMC7909650 DOI: 10.1371/journal.pone.0247838] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 02/12/2021] [Indexed: 11/25/2022] Open
Abstract
Bovine tuberculosis (bTb) is endemic in Bangladesh but the true prevalence has not yet been reported. Our objectives for this study were to determine the true prevalence and identify risk factors for bTb at the animal- and herd-level in Bangladesh. A total of 510 cows were randomly selected during January 2018 to December 2018. Caudal fold (CFT) and comparative cervical tuberculin tests (CCT) were serially interpreted. Animal- and herd-level risk factor data were collected using a pre-tested questionnaire. The hierarchical true prevalence of bTb was estimated within a Bayesian framework. The herd- and animal-level risk factors were identified using mixed effects logistic regression. The apparent prevalence of bTb was 20.6% [95% Confidence Interval (CI): 17.3; 24.3] based on CFT. The animal-level true prevalence of bTb was 21.9 (13.0; 32.4). The herd-level true prevalence in different regions varied from 41.9% to 88.8%. The region-level true prevalence was 49.9 (13.8; 91.2). There is a 100% certainty that herds from Bhaluka and Mymensingh Sadar upazilas are not free from bTb. The odds of bTb were 3.9 times (1.2; 12.6) higher in herds having more than four cows than those with ≤ 4 cows. On the other hand, the risk of bTb was 3.3 times higher (1.0; 10.5) in non-grazing cows than grazing cows. Crossbred cows were 2.9 times (1.5; 5.9) more likely to be infected with bTb than indigenous cows. The risk of bTb in animals with cough was 2.3 times (1.2; 4.3) higher than those without cough. Crossbred, non-grazing cows with cough should be targeted for bTb surveillance. Herds of the Mymensingh, Sadar and Bhaluka regions should be emphasized for bTb control programs. Estimation of Bayesian hierarchical true prevalence facilitates identification of areas with higher prevalence and can be used to indicate regions that where true prevalence exceeds a pre-specified critical threshold.
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Affiliation(s)
- Md. Nazimul Islam
- Faculty of Veterinary Science, Department of Medicine, Bangladesh Agricultural University, Mymensingh, Bangladesh
- Department of Livestock Services, Dhaka, Bangladesh
| | - Mohammad Kamruzzaman Khan
- Faculty of Veterinary Science, Department of Medicine, Bangladesh Agricultural University, Mymensingh, Bangladesh
- Department of Community Medicine, Mymensingh Medical College, Mymensingh, Bangladesh
| | - Mohammad Ferdousur Rahman Khan
- Faculty of Veterinary Science, Department of Microbiology and Hygiene, Bangladesh Agricultural University, Mymensingh, Bangladesh
| | - Polychronis Kostoulas
- Faculty of Public Health and One Health, Laboratory of Epidemiology & Artificial Intelligence, School of Health Sciences, University of Thessaly, Volos, Greece
| | - A. K. M. Anisur Rahman
- Faculty of Veterinary Science, Department of Medicine, Bangladesh Agricultural University, Mymensingh, Bangladesh
| | - Md. Mahbub Alam
- Faculty of Veterinary Science, Department of Medicine, Bangladesh Agricultural University, Mymensingh, Bangladesh
- * E-mail:
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Allen AR, Ford T, Skuce RA. Does Mycobacterium tuberculosis var. bovis Survival in the Environment Confound Bovine Tuberculosis Control and Eradication? A Literature Review. Vet Med Int 2021; 2021:8812898. [PMID: 33628412 PMCID: PMC7880718 DOI: 10.1155/2021/8812898] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 01/12/2021] [Accepted: 01/25/2021] [Indexed: 12/13/2022] Open
Abstract
Bovine tuberculosis (bTB) is one of the globe's most common, multihost zoonoses and results in substantial socioeconomic costs for governments, farming industries, and tax payers. Despite decades of surveillance and research, surprisingly, little is known about the exact mechanisms of transmission. In particular, as a facultative intracellular pathogen, to what extent does survival of the causative agent, Mycobacterium tuberculosis var. bovis (M. bovis), in the environment constitute an epidemiological risk for livestock and wildlife? Due largely to the classical pathology of cattle cases, the received wisdom was that bTB was spread by direct inhalation and exchange of bioaerosols containing droplets laden with bacteria. Other members of the Mycobacterium tuberculosis complex (MTBC) exhibit differing host ranges, an apparent capacity to persist in environmental fomites, and they favour a range of different transmission routes. It is possible, therefore, that infection from environmental sources of M. bovis could be a disease transmission risk. Recent evidence from GPS-collared cattle and badgers in Britain and Ireland suggests that direct transmission by infectious droplets or aerosols may not be the main mechanism for interspecies transmission, raising the possibility of indirect transmission involving a contaminated, shared environment. The possibility that classical pulmonary TB can be simulated and recapitulated in laboratory animal models by ingestion of contaminated feed is a further intriguing indication of potential environmental risk. Livestock and wildlife are known to shed M. bovis onto pasture, soil, feedstuffs, water, and other fomites; field and laboratory studies have indicated that persistence is possible, but variable, under differing environmental conditions. Given the potential infection risk, it is timely to review the available evidence, experimental approaches, and methodologies that could be deployed to address this potential blind spot and control point. Although we focus on evidence from Western Europe, the concepts are widely applicable to other multihost bTB episystems.
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Affiliation(s)
- Adrian R. Allen
- Agri-Food and Biosciences Institute, Veterinary Sciences Division, Bacteriology Branch, Stoney Road Stormont, Belfast BT4 3SD, Northern Ireland, UK
| | - Tom Ford
- Agri-Food and Biosciences Institute, Veterinary Sciences Division, Bacteriology Branch, Stoney Road Stormont, Belfast BT4 3SD, Northern Ireland, UK
| | - Robin A. Skuce
- Agri-Food and Biosciences Institute, Veterinary Sciences Division, Bacteriology Branch, Stoney Road Stormont, Belfast BT4 3SD, Northern Ireland, UK
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6
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Milton AAP, Das S, Ghatak S. Neglected paths of transmission of milkborne brucellosis and tuberculosis in developing countries: novel control opportunities. Epidemiol Health 2020; 42:e2020073. [PMID: 33285058 PMCID: PMC8137372 DOI: 10.4178/epih.e2020073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 12/02/2020] [Indexed: 11/23/2022] Open
Abstract
Brucellosis and tuberculosis are lingering zoonotic infections that are endemic in many developing parts of the world, with considerable economic and health costs. Although guidelines for the control of these diseases exist, we highlight neglected transmission routes of these diseases. We show that informal, door-to-door marketing of unpasteurized milk provides an important route for disease transmission through kitchen cross-contamination. Furthermore, the practice of discarding the first strippings of milk at farms needs adjustment to avoid floor and environmental contamination. Herein, we propose handling guidelines and a design for a milk stripping collection vessel. We believe that taking action to block these hitherto unrecognized transmission routes will complement existing efforts and guidelines.
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Affiliation(s)
| | - Samir Das
- Division of Animal Health, ICAR Research Complex for NEH Region, Umiam, India
| | - Sandeep Ghatak
- Division of Animal Health, ICAR Research Complex for NEH Region, Umiam, India
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7
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Milne G, Allen A, Graham J, Kirke R, McCormick C, Presho E, Skuce R, Byrne AW. Mycobacterium bovis Population Structure in Cattle and Local Badgers: Co-Localisation and Variation by Farm Type. Pathogens 2020; 9:pathogens9070592. [PMID: 32708155 PMCID: PMC7400278 DOI: 10.3390/pathogens9070592] [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: 05/25/2020] [Revised: 07/03/2020] [Accepted: 07/08/2020] [Indexed: 11/16/2022] Open
Abstract
Bovine tuberculosis surveillance in Northern Ireland includes Multiple-Locus Variable number tandem repeat Analysis (MLVA) to determine the Mycobacterium bovis genetic type present in both cattle and the predominant wildlife host, the European badger (Meles meles). These data are useful for investigating clusters of infection and understanding the scale at which interspecific transmission may occur. We utilised a comprehensive dataset of routinely sampled isolates from infected cattle and from badgers killed in road-traffic accidents to investigate the spatial co-location of MLVA types in, and between, the badger and cattle populations. Furthermore, we investigated the hypothesis that the type of farming enterprise might explain some variation in this relationship. MLVA types were spatially co-localised in cattle and road-traffic accident (RTA) badger hosts, indicative of a shared epidemic. Dairy herds were more likely to have at least one MLVA type in common with nearby RTA badgers, compared to non-dairy herd types. Marginally more MLVA spatial clustering was observed in non-dairy herds, which may be a consequence of relatively more between-herd movements. For the cattle population, local transmission mechanisms such as infection from contiguous herds, infectious wildlife and short-range between-herd cattle movements appear primarily to drive the epidemic: there appears to be a more limited role for long-range movements. Animal management practices are likely to be the driving force behind this observation, as beef rearing is associated with elevated numbers of animal movements compared to dairy herds.
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Affiliation(s)
- Georgina Milne
- Veterinary Sciences Division, Agri-Food and Biosciences Institute (AFBI), Belfast BT4 3SD, UK; (A.A.); (J.G.); (E.P.); (R.S.)
- Correspondence:
| | - Adrian Allen
- Veterinary Sciences Division, Agri-Food and Biosciences Institute (AFBI), Belfast BT4 3SD, UK; (A.A.); (J.G.); (E.P.); (R.S.)
| | - Jordon Graham
- Veterinary Sciences Division, Agri-Food and Biosciences Institute (AFBI), Belfast BT4 3SD, UK; (A.A.); (J.G.); (E.P.); (R.S.)
| | - Raymond Kirke
- Veterinary Epidemiology Unit, Department of Agriculture, Environment and Rural Affairs, Belfast BT4 3SB, UK;
| | - Carl McCormick
- Department of Agriculture, Environment and Rural Affairs, Veterinary Service Animal Health, Coleraine BT52 2AJ, UK;
| | - Eleanor Presho
- Veterinary Sciences Division, Agri-Food and Biosciences Institute (AFBI), Belfast BT4 3SD, UK; (A.A.); (J.G.); (E.P.); (R.S.)
| | - Robin Skuce
- Veterinary Sciences Division, Agri-Food and Biosciences Institute (AFBI), Belfast BT4 3SD, UK; (A.A.); (J.G.); (E.P.); (R.S.)
- School of Biological Sciences, Queen’s University Belfast, Belfast BT9 5DL, UK;
| | - Andrew W. Byrne
- School of Biological Sciences, Queen’s University Belfast, Belfast BT9 5DL, UK;
- One-Health Unit, Department of Agriculture, Food and the Marine, Agriculture House, Dublin, Ireland
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Miguel E, Grosbois V, Caron A, Pople D, Roche B, Donnelly CA. A systemic approach to assess the potential and risks of wildlife culling for infectious disease control. Commun Biol 2020; 3:353. [PMID: 32636525 PMCID: PMC7340795 DOI: 10.1038/s42003-020-1032-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 04/15/2020] [Indexed: 12/17/2022] Open
Abstract
The maintenance of infectious diseases requires a sufficient number of susceptible hosts. Host culling is a potential control strategy for animal diseases. However, the reduction in biodiversity and increasing public concerns regarding the involved ethical issues have progressively challenged the use of wildlife culling. Here, we assess the potential of wildlife culling as an epidemiologically sound management tool, by examining the host ecology, pathogen characteristics, eco-sociological contexts, and field work constraints. We also discuss alternative solutions and make recommendations for the appropriate implementation of culling for disease control.
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Affiliation(s)
- Eve Miguel
- Medical Research Council Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.
- MIVEGEC (Infectious Diseases and Vectors: Ecology, Genetics, Evolution and Control), IRD (Research Institute for Sustainable Development), CNRS (National Center for Scientific Research), Univ. Montpellier, Montpellier, France.
- CREES Centre for Research on the Ecology and Evolution of Disease, Montpellier, France.
| | - Vladimir Grosbois
- ASTRE (Animal, Health, Territories, Risks, Ecosystems), CIRAD (Agricultural Research for Development), Univ. Montpellier, INRA (French National Institute for Agricultural Research), Montpellier, France
| | - Alexandre Caron
- ASTRE (Animal, Health, Territories, Risks, Ecosystems), CIRAD (Agricultural Research for Development), Univ. Montpellier, INRA (French National Institute for Agricultural Research), Montpellier, France
| | - Diane Pople
- Medical Research Council Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Benjamin Roche
- MIVEGEC (Infectious Diseases and Vectors: Ecology, Genetics, Evolution and Control), IRD (Research Institute for Sustainable Development), CNRS (National Center for Scientific Research), Univ. Montpellier, Montpellier, France
- UMMISCO (Unité Mixte Internationnale de Modélisation Mathématique et Informatiques des Systèmes Complèxes, IRD/Sorbonne Université, Bondy, France
- Departamento de Etología, Fauna Silvestre y Animales de Laboratorio, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México (UNAM), Ciudad de, México, México
| | - Christl A Donnelly
- Medical Research Council Centre for Global Infectious Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
- Department of Statistics, University of Oxford, Oxford, UK
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9
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Milne G, Allen A, Graham J, Lahuerta-Marin A, McCormick C, Presho E, Reid N, Skuce R, Byrne AW. Bovine tuberculosis breakdown duration in cattle herds: an investigation of herd, host, pathogen and wildlife risk factors. PeerJ 2020; 8:e8319. [PMID: 32117602 PMCID: PMC7003687 DOI: 10.7717/peerj.8319] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 11/29/2019] [Indexed: 11/20/2022] Open
Abstract
Background Despite rigorous controls placed on herds which disclose ante-mortem test positive cattle to bovine tuberculosis, caused by the infection of Mycobacterium bovis, many herds in Northern Ireland (NI) experience prolonged breakdowns. These herds represent a considerable administrative and financial burden to the State and farming community. Methods A retrospective observational study was conducted to better understand the factors associated with breakdown duration, which was modelled using both negative binomial and ordinal regression approaches. Results Six explanatory variables were important predictors of breakdown length in both models; herd size, the number of reactors testing positive in the initial SICCT test, the presence of a lesioned animal at routine slaughter (LRS), the count of M. bovis genotypes during the breakdown (MLVA richness), the local herd-level bTB prevalence, and the presence of herds linked via management factors (associated herds). We report that between 2008 and 2014, mean breakdown duration in NI was 226 days (approx. seven months; median: 188 days). In the same period, however, more than 6% of herds in the region remained under movement restriction for more than 420 days (13 months); almost twice as long as the mean. The MLVA richness variable was a particularly important predictor of breakdown duration. We contend that this variable primarily represents a proxy for beef fattening herds, which can operate by purchasing cattle and selling animals straight to slaughter, despite prolonged trading restrictions. For other herd types, the model supports the hypothesis that prolonged breakdowns are a function of both residual infection within the herd, and infection from the environment (e.g. infected wildlife, contiguous herds and/or a contaminated environment). The impact of badger density on breakdown duration was assessed by including data on main sett (burrow) density. Whilst a positive association was observed in the univariate analysis, confounding with other variables means that the contribution of badgers to prolonged breakdowns was not clear from our study. We do not fully reject the hypothesis that badgers are implicated in prolonging bTB breakdowns via spillback infection, but given our results, we posit that increased disease risk from badgers is unlikely to simply be a function of increasing badger density measured using sett metrics.
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Affiliation(s)
- Georgina Milne
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom
| | - Adrian Allen
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom
| | - Jordon Graham
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom
| | - Angela Lahuerta-Marin
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom
| | - Carl McCormick
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom.,Department of Agriculture, Environment, and Rural Affairs, Coleraine, United Kingdom
| | - Eleanor Presho
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom
| | - Neil Reid
- School of Biological Sciences, Queen's University Belfast, Belfast, United Kingdom
| | - Robin Skuce
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom
| | - Andrew W Byrne
- Veterinary Sciences Division, Agri-food and Biosciences Institute, Belfast, United Kingdom.,School of Biological Sciences, Queen's University Belfast, Belfast, United Kingdom.,One-Health Scientific Support Unit, Department of Agriculture, Food and the Marine, Dublin, Ireland
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10
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Crispell J, Benton CH, Balaz D, De Maio N, Ahkmetova A, Allen A, Biek R, Presho EL, Dale J, Hewinson G, Lycett SJ, Nunez-Garcia J, Skuce RA, Trewby H, Wilson DJ, Zadoks RN, Delahay RJ, Kao RR. Combining genomics and epidemiology to analyse bi-directional transmission of Mycobacterium bovis in a multi-host system. eLife 2019; 8:e45833. [PMID: 31843054 PMCID: PMC6917503 DOI: 10.7554/elife.45833] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 10/15/2019] [Indexed: 01/02/2023] Open
Abstract
Quantifying pathogen transmission in multi-host systems is difficult, as exemplified in bovine tuberculosis (bTB) systems, but is crucial for control. The agent of bTB, Mycobacterium bovis, persists in cattle populations worldwide, often where potential wildlife reservoirs exist. However, the relative contribution of different host species to bTB persistence is generally unknown. In Britain, the role of badgers in infection persistence in cattle is highly contentious, despite decades of research and control efforts. We applied Bayesian phylogenetic and machine-learning approaches to bacterial genome data to quantify the roles of badgers and cattle in M. bovis infection dynamics in the presence of data biases. Our results suggest that transmission occurs more frequently from badgers to cattle than vice versa (10.4x in the most likely model) and that within-species transmission occurs at higher rates than between-species transmission for both. If representative, our results suggest that control operations should target both cattle and badgers.
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Affiliation(s)
- Joseph Crispell
- School of Veterinary Medicine, Veterinary Sciences CentreUniversity College DublinDublinIreland
| | - Clare H Benton
- National Wildlife Management CentreAnimal & Plant Health Agency (APHA)LondonUnited Kingdom
| | - Daniel Balaz
- Roslin InstituteUniversity of EdinburghEdinburghUnited Kingdom
| | - Nicola De Maio
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI)CambridgeUnited Kingdom
| | - Assel Ahkmetova
- Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life SciencesUniversity of GlasgowGlasgowUnited Kingdom
| | - Adrian Allen
- Agri-Food & Biosciences Institute Northern Ireland (AFBNI)BelfastUnited Kingdom
| | - Roman Biek
- Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life SciencesUniversity of GlasgowGlasgowUnited Kingdom
| | - Eleanor L Presho
- Agri-Food & Biosciences Institute Northern Ireland (AFBNI)BelfastUnited Kingdom
| | - James Dale
- Animal & Plant Health Agency (APHA)LondonUnited Kingdom
| | - Glyn Hewinson
- Centre for Bovine Tuberculosis, Institute of Biological, Environmental and Rural SciencesUniversity of AberystwythAberystwythUnited Kingdom
| | | | | | - Robin A Skuce
- Agri-Food & Biosciences Institute Northern Ireland (AFBNI)BelfastUnited Kingdom
| | | | - Daniel J Wilson
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Population HealthUniversity of OxfordOxfordUnited Kingdom
| | - Ruth N Zadoks
- Institute of Biodiversity, Animal Health & Comparative Medicine, College of Medical, Veterinary & Life SciencesUniversity of GlasgowGlasgowUnited Kingdom
| | - Richard J Delahay
- National Wildlife Management CentreAnimal & Plant Health Agency (APHA)LondonUnited Kingdom
| | - Rowland Raymond Kao
- Roslin InstituteUniversity of EdinburghEdinburghUnited Kingdom
- Royal (Dick) School of Veterinary StudiesUniversity of EdinburghEdinburghUnited Kingdom
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Campbell EL, Byrne AW, Menzies FD, McBride KR, McCormick CM, Scantlebury M, Reid N. Interspecific visitation of cattle and badgers to fomites: A transmission risk for bovine tuberculosis? Ecol Evol 2019; 9:8479-8489. [PMID: 31410255 PMCID: PMC6686281 DOI: 10.1002/ece3.5282] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 04/04/2019] [Accepted: 04/23/2019] [Indexed: 01/10/2023] Open
Abstract
In Great Britain and Ireland, badgers (Meles meles) are a wildlife reservoir of Mycobacterium bovis and implicated in bovine tuberculosis transmission to domestic cattle. The route of disease transmission is unknown with direct, so-called "nose-to-nose," contact between hosts being extremely rare. Camera traps were deployed for 64,464 hr on 34 farms to quantify cattle and badger visitation rates in space and time at six farm locations. Badger presence never coincided with cattle presence at the same time, with badger and cattle detection at the same location but at different times being negatively correlated. Badgers were never recorded within farmyards during the present study. Badgers utilized cattle water troughs in fields, but detections were infrequent (equivalent to one badger observed drinking every 87 days). Cattle presence at badger-associated locations, for example, setts and latrines, were three times more frequent than badger presence at cattle-associated locations, for example, water troughs. Preventing cattle access to badger setts and latrines and restricting badger access to cattle water troughs may potentially reduce interspecific bTB transmission through reduced indirect contact.
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Affiliation(s)
- Emma L. Campbell
- School of Biological SciencesQueen's University BelfastBelfastUK
- Veterinary Sciences DivisionAgri‐Food and Biosciences Institute (AFBI)BelfastUK
| | - Andrew W. Byrne
- School of Biological SciencesQueen's University BelfastBelfastUK
- Veterinary Sciences DivisionAgri‐Food and Biosciences Institute (AFBI)BelfastUK
- Present address:
Department of AgricultureFood and the Marine (DAFM), Agriculture HouseDublin 2Ireland
| | - Fraser D. Menzies
- Veterinary Epidemiology Unit, Department of AgricultureEnvironment and Rural Affairs (DAERA)BelfastUK
| | - Kathryn R. McBride
- Veterinary Epidemiology Unit, Department of AgricultureEnvironment and Rural Affairs (DAERA)BelfastUK
| | - Carl M. McCormick
- Veterinary Sciences DivisionAgri‐Food and Biosciences Institute (AFBI)BelfastUK
- Veterinary Epidemiology Unit, Department of AgricultureEnvironment and Rural Affairs (DAERA)BelfastUK
| | - Michael Scantlebury
- School of Biological SciencesQueen's University BelfastBelfastUK
- Institute for Global Food Security (IGFS)Queen's University BelfastBelfastUK
| | - Neil Reid
- School of Biological SciencesQueen's University BelfastBelfastUK
- Institute for Global Food Security (IGFS)Queen's University BelfastBelfastUK
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12
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Milne MG, Graham J, Allen A, McCormick C, Presho E, Skuce R, Byrne AW. Variation in Mycobacterium bovis genetic richness suggests that inwards cattle movements are a more important source of infection in beef herds than in dairy herds. BMC Microbiol 2019; 19:154. [PMID: 31277578 PMCID: PMC6612228 DOI: 10.1186/s12866-019-1530-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 06/25/2019] [Indexed: 02/08/2023] Open
Abstract
Background We used genetic Multi-Locus VNTR Analysis (MLVA) data gathered from surveillance efforts to better understand the ongoing bovine tuberculosis (bTB) epidemic in Northern Irish cattle herds. We modelled the factors associated with Mycobacterium bovis MLVA genotype richness at three analytical scales; breakdown level, herd level, and patch level, and compared the results between dairy and non-dairy production types. Results In 83% of breakdowns and in 63% of herds, a single MLVA genotype was isolated. Five or more MLVA genotypes were found in less than 3 % of herds. Herd size and the total number of reactors were important explanatory variables, suggesting that increasing MLVA genotype richness was positively related to increases in the number of host animals. Despite their smaller relative size, however, the highest MLVA genotype richness values were observed in non-dairy herds. Increasing inwards cattle movements were important positive predictors of MLVA genotype richness, but mainly in non-dairy settings. Conclusions The principal finding is that low MLVA genotype richness indicates that small-scale epidemics, e.g. wildlife, contiguous farms, and within-herd recrudescence, are important routes of M. bovis infection in cattle herds. We hypothesise that these mechanisms will maintain, but may not explicitly increase, MLVA genotype richness. The presence of elevated MLVA richness is relatively rare and likely indicates beef fattening enterprises, which purchase cattle from over long distances. Cattle movements were furthermore an important predictor of MLVA genotype richness in non-dairy herds, but not in dairy herds; this may represent reduced cattle purchasing levels in dairy enterprises, compared to beef. These observations allude to the relative contribution of different routes of bTB infection between production types; we posit that infection associated with local factors may be more evident in dairy herds than beef herds, however in beef herds, inwards movements offer additional opportunities for introducing M. bovis into the herd. Electronic supplementary material The online version of this article (10.1186/s12866-019-1530-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- M G Milne
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), 12 Stoney Road, Stormont, Belfast, BT4 3SD, UK.
| | - J Graham
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), 12 Stoney Road, Stormont, Belfast, BT4 3SD, UK
| | - A Allen
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), 12 Stoney Road, Stormont, Belfast, BT4 3SD, UK
| | - C McCormick
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), 12 Stoney Road, Stormont, Belfast, BT4 3SD, UK.,Department of Agriculture, Environment and Rural Affairs (DAERA), Veterinary Service Animal Health, Coleraine, UK
| | - E Presho
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), 12 Stoney Road, Stormont, Belfast, BT4 3SD, UK
| | - R Skuce
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), 12 Stoney Road, Stormont, Belfast, BT4 3SD, UK
| | - A W Byrne
- Veterinary Sciences Division, Agri-food and Biosciences Institute (AFBI), 12 Stoney Road, Stormont, Belfast, BT4 3SD, UK.,School of Biological Sciences, Queen's University, Belfast, UK.,Present Address: Surveillance, Animal By-Products, and TSEs (SAT) Division, Department of Agriculture, Food and Marine (DAFM), Agriculture House, Dublin 2, Ireland
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13
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Performativity and a microbe: Exploring Mycobacterium bovis and the political ecologies of bovine tuberculosis. BIOSOCIETIES 2018; 14:179-204. [PMID: 32226469 PMCID: PMC7100403 DOI: 10.1057/s41292-018-0124-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Mycobacterium bovis, the bacterium responsible for causing bovine tuberculosis (bTB) in cattle, displays what I call ‘microbial performativity’. Like many other lively disease-causing microorganisms, it has an agency which is difficult to contain, and there is a need for fresh thinking on the challenges of dealing with this slippery and indeterminate microbe. As a practising veterinary scientist who side-stepped mid-career into a parallel training in the social sciences to view bTB from an alternative perspective, I create an interdisciplinary coming-together where veterinary science converges with a political ecology of (animal) health influenced by science and technology studies (STS) and social science and humanities scholarship on performativity. This suitably hybridized nexus creates a place to consider the ecologies of a pathogen which could be considered as life out of control. I consider what this means for efforts to eradicate this disease through combining understandings from the published scientific literature with qualitative interview-based fieldwork with farmers, veterinarians and others involved in the statutory bTB eradication programme in a high incidence region of the UK. This study demonstrates the value of life scientists turning to the social sciences to re-view their familiar professional habitus—challenging assumptions, and offering alternative perspectives on complex problems.
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14
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Byrne AW, Graham J, Brown C, Donaghy A, Guelbenzu-Gonzalo M, McNair J, Skuce R, Allen A, McDowell S. Bovine tuberculosis visible lesions in cattle culled during herd breakdowns: the effects of individual characteristics, trade movement and co-infection. BMC Vet Res 2017; 13:400. [PMID: 29284483 PMCID: PMC5747088 DOI: 10.1186/s12917-017-1321-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 12/14/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Bovine tuberculosis (bTB), caused by Mycobacterium bovis, remains a significant problem for livestock industries in many countries worldwide including Northern Ireland, where a test and slaughter regime has utilised the Single Intradermal Comparative Cervical Tuberculin (SICCT) test since 1959. We investigated the variation in post-mortem confirmation based on bTB visible lesion (VL) presence during herd breakdowns using two model suites. We investigated animal-level characteristics, while controlling for herd-level factors and clustering. We were interested in potential impacts of concurrent infection, and therefore we assessed whether animals with evidence of liver fluke infection (Fasciola hepatica; post-mortem inspection), M. avium reactors (animals with negative M. bovis-avium (b-a) tuberculin reactions) or Bovine Viral Diarrhoea Virus (BVDV; RT-PCR tested) were associated with bTB confirmation. RESULTS The dataset included 6242 animals removed during the 14 month study period (2013-2015). bTB-VL presence was significantly increased in animals with greater b-a reaction size at the disclosing SICCT test (e.g. b-a = 5-9 mm vs. b-a = 0 mm, adjusted Odds ratio (aOR): 14.57; p < 0.001). M. avium reactor animals (b-a < 0) were also significantly more likely to disclose VL than non-reactor animals (b-a = 0; aOR: 2.29; p = 0.023). Animals had a greater probability of exhibiting lesions with the increasing number of herds it had resided within (movement; log-herds: aOR: 2.27-2.42; p < 0.001), if it had an inconclusive penultimate test result (aOR: 2.84-3.89; p < 0.001), and with increasing time between tests (log-time; aOR: 1.23; p = 0.003). Animals were less likely to have VL if they were a dairy breed (aOR: 0.79; p = 0.015) or in an older age-class (e.g. age-quartile 2 vs. 4; aOR: 0.65; p < 0.001). Liver fluke or BVDV variables were not retained in either multivariable model as they were non-significantly associated with bTB-VL status (p > 0.1). CONCLUSIONS Our results suggest that neither co-infection of liver fluke nor BVDV had a significant effect on the presence of VLs in this high-risk cohort. M. avium tuberculin reactors had a significantly increased risk of disclosing with a bTB lesion, which could be related to the impact of co-infection with M. avium subsp. paratuberculosis (MAP) affecting the performance of the SICCT however further research in this area is required. Movements, test history, breed and age were important factors influencing confirmation in high-risk animals.
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Affiliation(s)
- Andrew W Byrne
- Agri-food and Biosciences Institute, Veterinary Science Division, Stormont, Belfast, Northern Ireland, BT43SD, UK. .,School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland, UK.
| | - Jordon Graham
- Agri-food and Biosciences Institute, Veterinary Science Division, Stormont, Belfast, Northern Ireland, BT43SD, UK
| | - Craig Brown
- Agri-food and Biosciences Institute, Veterinary Science Division, Stormont, Belfast, Northern Ireland, BT43SD, UK
| | - Aoibheann Donaghy
- Agri-food and Biosciences Institute, Veterinary Science Division, Stormont, Belfast, Northern Ireland, BT43SD, UK
| | - Maria Guelbenzu-Gonzalo
- Agri-food and Biosciences Institute, Veterinary Science Division, Stormont, Belfast, Northern Ireland, BT43SD, UK
| | - Jim McNair
- Agri-food and Biosciences Institute, Veterinary Science Division, Stormont, Belfast, Northern Ireland, BT43SD, UK
| | - Robin Skuce
- Agri-food and Biosciences Institute, Veterinary Science Division, Stormont, Belfast, Northern Ireland, BT43SD, UK
| | - Adrian Allen
- Agri-food and Biosciences Institute, Veterinary Science Division, Stormont, Belfast, Northern Ireland, BT43SD, UK
| | - Stanley McDowell
- Agri-food and Biosciences Institute, Veterinary Science Division, Stormont, Belfast, Northern Ireland, BT43SD, UK
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15
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Bolaños CAD, Paula CLD, Guerra ST, Franco MMJ, Ribeiro MG. Diagnosis of mycobacteria in bovine milk: an overview. Rev Inst Med Trop Sao Paulo 2017; 59:e40. [PMID: 28591268 PMCID: PMC5466425 DOI: 10.1590/s1678-9946201759040] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 02/22/2017] [Indexed: 11/22/2022] Open
Abstract
Tuberculosis remains as the world's biggest threat. In 2014, human tuberculosis ranked as a major infectious disease by the first time, overcoming HIV death rates. Bovine tuberculosis is a chronic disease of global distribution that affects animals and can be transmitted to humans by the consumption of raw milk, representing a serious public health concern. Despite the efforts of different countries to control and eradicate bovine tuberculosis, the high negative economic impact on meat and milk production chains remains, given the decreased production efficiency (approximately 25%), the high number of condemned carcasses, and increased animal culling rates. This scenario has motivated the establishment of official programs based on regulations and diagnostic procedures. Although Mycobacterium tuberculosis and Mycobacterium bovis are the major pathogenic species to humans and bovines, respectively, nontuberculous mycobacteria within the Mycobacterium genus have become increasingly important in recent decades due to human infections, including the ones that occur in immunocompetent people. Diagnosis of mycobacteria can be performed by microbiological culture from tissue samples (lymph nodes, lungs) and secretions (sputum, milk). In general, these pathogens demand special nutrient requirements for isolation/growth, and the use of selective and rich culture media. Indeed, within these genera, mycobacteria are classified as either fast- or slow-growth microorganisms. Regarding the latter ones, incubation times can vary from 45 to 90 days. Although microbiological culture is still considered the gold standard method for diagnosis, molecular approaches have been increasingly used. We describe here an overview of the diagnosis of Mycobacterium species in bovine milk.
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Affiliation(s)
- Carmen Alicia Daza Bolaños
- UNESP - Universidade Estadual Paulista Julio de Mesquita Filho, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Higiene Veterinária e Saúde Pública, Botucatu, São Paulo, Brazil
| | - Carolina Lechinski de Paula
- UNESP - Universidade Estadual Paulista Julio de Mesquita Filho, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Higiene Veterinária e Saúde Pública, Botucatu, São Paulo, Brazil
| | - Simony Trevizan Guerra
- UNESP - Universidade Estadual Paulista Julio de Mesquita Filho, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Higiene Veterinária e Saúde Pública, Botucatu, São Paulo, Brazil
| | - Marília Masello Junqueira Franco
- UNESP - Universidade Estadual Paulista Julio de Mesquita Filho, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Higiene Veterinária e Saúde Pública, Botucatu, São Paulo, Brazil
| | - Márcio Garcia Ribeiro
- UNESP - Universidade Estadual Paulista Julio de Mesquita Filho, Faculdade de Medicina Veterinária e Zootecnia, Departamento de Higiene Veterinária e Saúde Pública, Botucatu, São Paulo, Brazil
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16
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Meunier NV, Sebulime P, White RG, Kock R. Wildlife-livestock interactions and risk areas for cross-species spread of bovine tuberculosis. Onderstepoort J Vet Res 2017; 84:e1-e10. [PMID: 28155286 PMCID: PMC6238759 DOI: 10.4102/ojvr.v84i1.1221] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 06/12/2016] [Accepted: 07/21/2016] [Indexed: 11/01/2022] Open
Abstract
The transmission of diseases between livestock and wildlife can be a hindrance to effective disease control. Maintenance hosts and contact rates should be explored to further understand the transmission dynamics at the wildlife-livestock interface. Bovine tuberculosis (BTB) has been shown to have wildlife maintenance hosts and has been confirmed as present in the African buffalo (Syncerus caffer) in the Queen Elizabeth National Park (QENP) in Uganda since the 1960s. The first aim of this study was to explore the spatio-temporal spread of cattle illegally grazing within the QENP recorded by the Uganda Wildlife Authority (UWA) rangers in a wildlife crime database. Secondly, we aimed to quantify wildlife-livestock interactions and cattle movements, on the border of QENP, using a longitudinal questionnaire completed by 30 livestock owners. From this database, 426 cattle sightings were recorded within QENP in 8 years. Thirteen (3.1%) of these came within a 300 m-4 week space-time window of a buffalo herd, using the recorded GPS data. Livestock owners reported an average of 1.04 (95% CI 0.97-1.11) sightings of Uganda kob, waterbuck, buffalo or warthog per day over a 3-month period, with a rate of 0.22 (95% CI 0.20-0.25) sightings of buffalo per farmer per day. Reports placed 85.3% of the ungulate sightings and 88.0% of the buffalo sightings as further than 50 m away. Ungulate sightings were more likely to be closer to cattle at the homestead (OR 2.0, 95% CI 1.1-3.6) compared with the grazing area. Each cattle herd mixed with an average of five other cattle herds at both the communal grazing and watering points on a daily basis. Although wildlife and cattle regularly shared grazing and watering areas, they seldom came into contact close enough for aerosol transmission. Between species infection transmission is therefore likely to be by indirect or non-respiratory routes, which is suspected to be an infrequent mechanism of transmission of BTB. Occasional cross-species spillover of infection is possible, and the interaction of multiple wildlife species needs further investigation. Controlling the interface between wildlife and cattle in a situation where eradication is not being considered may have little impact on BTB disease control in cattle.
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Affiliation(s)
- Natascha V Meunier
- Department of Pathology and Pathogen Biology, Royal Veterinary College; Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine.
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Divergent macrophage responses to Mycobacterium bovis among naturally exposed uninfected and infected cattle. Immunol Cell Biol 2016; 95:436-442. [PMID: 27833091 DOI: 10.1038/icb.2016.114] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 11/07/2016] [Accepted: 11/07/2016] [Indexed: 01/04/2023]
Abstract
Mycobacterium bovis, the causative agent of bovine tuberculosis (TB), is a successful pathogen that remains an important global threat to livestock. Cattle naturally exposed to M. bovis normally become reactive to the M. bovis-purified protein derivative (tuberculin) skin test; however, some individuals remain negative, suggesting that they may be resistant to infection. To better understand host innate resistance to infection, 26 cattle from herds with a long history of high TB prevalence were included in this study. We investigated the bactericidal activity, the production of reactive oxygen and nitrogen species and the TB-related gene expression profile after in vitro M. bovis challenge of monocyte-derived macrophages from cattle with TB (n=17) and from non-infected, exposed cattle (in-contacts, n=9). The disease status was established based on the tuberculin skin test and blood interferon-gamma test responses, the presence of visible lesions at inspection on abattoirs and the histopathology and culture of M. bovis. Although macrophages from TB-infected cattle enabled M. bovis replication, macrophages from healthy, exposed cattle had twofold lower bacterial loads, overproduced nitric oxide and had lower interleukin (IL)-10 gene expression (P⩽0.05). Higher mRNA expression levels of inducible nitric oxide synthase, C-C motif chemokine ligand 2 and IL-12 were observed in macrophages from all in-contact cattle than in macrophages from their TB-infected counterparts, which expressed more tumour necrosis factor-α; however, the differences were not statistically significant owing to individual variation. These results confirm that macrophage bactericidal responses have a crucial role in innate resistance to M. bovis infection in cattle.
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Dejene SW, Heitkönig IMA, Prins HHT, Lemma FA, Mekonnen DA, Alemu ZE, Kelkay TZ, de Boer WF. Risk Factors for Bovine Tuberculosis (bTB) in Cattle in Ethiopia. PLoS One 2016; 11:e0159083. [PMID: 27404387 PMCID: PMC4942063 DOI: 10.1371/journal.pone.0159083] [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: 03/30/2016] [Accepted: 06/27/2016] [Indexed: 11/22/2022] Open
Abstract
Bovine tuberculosis (bTB) infection is generally correlated with individual cattle's age, sex, body condition, and with husbandry practices such as herd composition, cattle movement, herd size, production system and proximity to wildlife-including bTB maintenance hosts. We tested the correlation between those factors and the prevalence of bTB, which is endemic in Ethiopia's highland cattle, in the Afar Region and Awash National Park between November 2013 and April 2015. A total of 2550 cattle from 102 herds were tested for bTB presence using the comparative intradermal tuberculin test (CITT). Data on herd structure, herd movement, management and production system, livestock transfer, and contact with wildlife were collected using semi-structured interviews with cattle herders and herd owners. The individual overall prevalence of cattle bTB was 5.5%, with a herd prevalence of 46%. Generalized Linear Mixed Models with a random herd-effect were used to analyse risk factors of cattle reactors within each herd. The older the age of the cattle and the lower the body condition the higher the chance of a positive bTB test result, but sex, lactation status and reproductive status were not correlated with bTB status. At herd level, General Linear Models showed that pastoral production systems with transhumant herds had a higher bTB prevalence than sedentary herds. A model averaging analysis identified herd size, contact with wildlife, and the interaction of herd size and contact with wildlife as significant risk factors for bTB prevalence in cattle. A subsequent Structural Equation Model showed that the probability of contact with wildlife was influenced by herd size, through herd movement. Larger herds moved more and grazed in larger areas, hence the probability of grazing in an area with wildlife and contact with either infected cattle or infected wildlife hosts increased, enhancing the chances for bTB infection. Therefore, future bTB control strategies in cattle in pastoral areas should consider herd size and movement as important risk factors.
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Affiliation(s)
- Sintayehu W. Dejene
- Resource Ecology Group, Wageningen University, Wageningen, the Netherlands
- College of Agriculture and Environmental Sciences, Haramaya University, Dire Dawa, Ethiopia
| | | | | | - Fitsum A. Lemma
- College of Veterinary Medicine, Haramaya University, Dire Dawa, Ethiopia
| | - Daniel A. Mekonnen
- College of Veterinary Medicine, Haramaya University, Dire Dawa, Ethiopia
| | - Zelalem E. Alemu
- College of Agriculture and Environmental Sciences, Haramaya University, Dire Dawa, Ethiopia
| | - Tessema Z. Kelkay
- College of Agriculture and Environmental Sciences, Haramaya University, Dire Dawa, Ethiopia
| | - Willem F. de Boer
- Resource Ecology Group, Wageningen University, Wageningen, the Netherlands
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Ghebremariam MK, Rutten VPMG, Vernooij JCM, Uqbazghi K, Tesfaalem T, Butsuamlak T, Idris AM, Nielen M, Michel AL. Prevalence and risk factors of bovine tuberculosis in dairy cattle in Eritrea. BMC Vet Res 2016; 12:80. [PMID: 27225267 PMCID: PMC4881182 DOI: 10.1186/s12917-016-0705-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 05/22/2016] [Indexed: 11/20/2022] Open
Abstract
Background The prevalence of bovine tuberculosis (BTB) in dairy cattle in the three major milk producing regions of Eritrea was assessed by subjecting 15,354 dairy cattle, 50 % of Eritrea’s dairy cattle population, to the single intradermal comparative tuberculin test (SICTT). Skin test results were interpreted according to guidelines of the World Organization for Animal Health (OIE) with >4 mm as cutoff in skin thickness increase. In addition, we studied the relation between ‘physiological’ variables related to pregnancy and lactation, and the variable ‘region’ on the probability to be skin test positive. Results The BTB prevalences at animal and herd levels were: 21.5 % and 40.9 % in Maekel, 7.3 % and 10 % in Debub, and 0.2 % and 1.6 % in the Anseba region, respectively. Overall, in the regions included, prevalence was 11.3 % (confidence interval (CI) 95 % CI, 11.29 – 11.31 %) and 17.3 % (95 % CI, 17.27–17.33 %), at animal and herd level, respectively. Considering positive herds only, the animal BTB prevalence was 36.8 %, 30.1 %, and 1.8 %, in Maekel, Debub and Anseba, respectively, and the overall animal prevalence within these herds was 32 %. In adult dairy cattle the probability of positive reactivity in the SICTT test was highest in pregnant animals as compared to the other categories. Conclusion This study reports persistent prevalence of BTB as defined by positive SICTT in the dairy sector of Eritrea, especially in the regions of Maekel and Debub that are located in the central highlands of the country. To our understanding this is the first report that has encompassed all the major dairy farms in Eritrea and it will be instrumental in advocating future BTB control programs in the dairy sector. Electronic supplementary material The online version of this article (doi:10.1186/s12917-016-0705-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Michael K Ghebremariam
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands. .,Department of Veterinary Sciences, Hamelmalo Agricultural College, Keren, Eritrea.
| | - V P M G Rutten
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.,Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - J C M Vernooij
- Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - K Uqbazghi
- Veterinary Services, Ministry of Agriculture (MOA), Mendefera, Debub Region, Eritrea
| | - T Tesfaalem
- National Animal and Plant Health Laboratory, MOA, Asmara, Eritrea
| | - T Butsuamlak
- Veterinary Services, MOA, Keren, Anseba Region, Eritrea
| | - A M Idris
- Veterinary Services, MOA, Asmara, Maekel Region, Eritrea
| | - M Nielen
- Department of Farm Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - A L Michel
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
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20
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Nalpas NC, Magee DA, Conlon KM, Browne JA, Healy C, McLoughlin KE, Rue-Albrecht K, McGettigan PA, Killick KE, Gormley E, Gordon SV, MacHugh DE. RNA sequencing provides exquisite insight into the manipulation of the alveolar macrophage by tubercle bacilli. Sci Rep 2015; 5:13629. [PMID: 26346536 PMCID: PMC4642568 DOI: 10.1038/srep13629] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 07/31/2015] [Indexed: 12/24/2022] Open
Abstract
Mycobacterium bovis, the agent of bovine tuberculosis, causes an estimated $3 billion annual losses to global agriculture due, in part, to the limitations of current diagnostics. Development of next-generation diagnostics requires a greater understanding of the interaction between the pathogen and the bovine host. Therefore, to explore the early response of the alveolar macrophage to infection, we report the first application of RNA-sequencing to define, in exquisite detail, the transcriptomes of M. bovis-infected and non-infected alveolar macrophages from ten calves at 2, 6, 24 and 48 hours post-infection. Differentially expressed sense genes were detected at these time points that revealed enrichment of innate immune signalling functions, and transcriptional suppression of host defence mechanisms (e.g., lysosome maturation). We also detected differentially expressed natural antisense transcripts, which may play a role in subverting innate immune mechanisms following infection. Furthermore, we report differential expression of novel bovine genes, some of which have immune-related functions based on orthology with human proteins. This is the first in-depth transcriptomics investigation of the alveolar macrophage response to the early stages of M. bovis infection and reveals complex patterns of gene expression and regulation that underlie the immunomodulatory mechanisms used by M. bovis to evade host defence mechanisms.
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Affiliation(s)
- Nicolas C Nalpas
- Animal Genomics Laboratory, UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - David A Magee
- Animal Genomics Laboratory, UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Kevin M Conlon
- UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - John A Browne
- Animal Genomics Laboratory, UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Claire Healy
- UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Kirsten E McLoughlin
- Animal Genomics Laboratory, UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Kévin Rue-Albrecht
- Animal Genomics Laboratory, UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland.,UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Paul A McGettigan
- Animal Genomics Laboratory, UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Kate E Killick
- Systems Biology Ireland, UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Eamonn Gormley
- Tuberculosis Diagnostics and Immunology Research Centre, UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
| | - Stephen V Gordon
- UCD School of Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland.,UCD School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland.,UCD School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.,UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - David E MacHugh
- Animal Genomics Laboratory, UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin 4, Ireland.,UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland
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21
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de la Cruz ML, Perez A, Bezos J, Pages E, Casal C, Carpintero J, Romero B, Dominguez L, Barker CM, Diaz R, Alvarez J. Spatial dynamics of bovine tuberculosis in the Autonomous Community of Madrid, Spain (2010-2012). PLoS One 2014; 9:e115632. [PMID: 25536514 PMCID: PMC4275235 DOI: 10.1371/journal.pone.0115632] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 11/05/2014] [Indexed: 12/31/2022] Open
Abstract
Progress in control of bovine tuberculosis (bTB) is often not uniform, usually due to the effect of one or more sometimes unknown epidemiological factors impairing the success of eradication programs. Use of spatial analysis can help to identify clusters of persistence of disease, leading to the identification of these factors thus allowing the implementation of targeted control measures, and may provide some insights of disease transmission, particularly when combined with molecular typing techniques. Here, the spatial dynamics of bTB in a high prevalence region of Spain were assessed during a three year period (2010-2012) using data from the eradication campaigns to detect clusters of positive bTB herds and of those infected with certain Mycobacterium bovis strains (characterized using spoligotyping and VNTR typing). In addition, the within-herd transmission coefficient (β) was estimated in infected herds and its spatial distribution and association with other potential outbreak and herd variables was evaluated. Significant clustering of positive herds was identified in the three years of the study in the same location ("high risk area"). Three spoligotypes (SB0339, SB0121 and SB1142) accounted for >70% of the outbreaks detected in the three years. VNTR subtyping revealed the presence of few but highly prevalent strains within the high risk area, suggesting maintained transmission in the area. The spatial autocorrelation found in the distribution of the estimated within-herd transmission coefficients in herds located within distances <14 km and the results of the spatial regression analysis, support the hypothesis of shared local factors affecting disease transmission in farms located at a close proximity.
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Affiliation(s)
- Maria Luisa de la Cruz
- Centro de Vigilancia Sanitaria Veterinaria VISAVET, Universidad Complutense, Madrid, Spain
| | - Andres Perez
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Javier Bezos
- Centro de Vigilancia Sanitaria Veterinaria VISAVET, Universidad Complutense, Madrid, Spain
- MAEVA SERVET SL, Alameda del Valle, Madrid, Spain
| | - Enrique Pages
- Área de Ganadería, Dirección General de Medio Ambiente, Consejería de Medio Ambiente, Vivienda y Ordenación del Territorio de la Comunidad de Madrid, Madrid, Spain
| | - Carmen Casal
- Centro de Vigilancia Sanitaria Veterinaria VISAVET, Universidad Complutense, Madrid, Spain
| | - Jesus Carpintero
- Área de Ganadería, Dirección General de Medio Ambiente, Consejería de Medio Ambiente, Vivienda y Ordenación del Territorio de la Comunidad de Madrid, Madrid, Spain
| | - Beatriz Romero
- Centro de Vigilancia Sanitaria Veterinaria VISAVET, Universidad Complutense, Madrid, Spain
| | - Lucas Dominguez
- Área de Ganadería, Dirección General de Medio Ambiente, Consejería de Medio Ambiente, Vivienda y Ordenación del Territorio de la Comunidad de Madrid, Madrid, Spain
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain
| | - Christopher M. Barker
- Center for Vectorborne Diseases and Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California Davis, Davis, California, United States of America
| | - Rosa Diaz
- Área de Ganadería, Dirección General de Medio Ambiente, Consejería de Medio Ambiente, Vivienda y Ordenación del Territorio de la Comunidad de Madrid, Madrid, Spain
| | - Julio Alvarez
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, Minnesota, United States of America
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22
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Three-dimensional in vitro models of granuloma to study bacteria-host interactions, drug-susceptibility, and resuscitation of dormant mycobacteria. BIOMED RESEARCH INTERNATIONAL 2014; 2014:623856. [PMID: 24967387 PMCID: PMC4055484 DOI: 10.1155/2014/623856] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 04/16/2014] [Indexed: 12/02/2022]
Abstract
Mycobacterium tuberculosis, Mycobacterium leprae, Mycobacterium bovis, and Mycobacterium avium subsp. paratuberculosis can survive within host macrophages in a dormant state, encased within an organized aggregate of immune host cells called granuloma. Granulomas consist of uninfected macrophages, foamy macrophages, epithelioid cells, and T lymphocytes accumulated around infected macrophages. Within granulomas, activated macrophages can fuse to form multinucleated giant cells, also called giant Langhans cells. A rim of T lymphocytes surrounds the core, and a tight coat of fibroblast closes the structure. Several in vivo models have been used to study granuloma's structure and function, but recently developed in vitro models of granuloma show potential for closer observation of the early stages of host's responses to live mycobacteria. This paper reviews culture conditions that resulted in three-dimensional granulomas, formed by the adhesion of cell populations in peripheral blood mononuclear cells infected with mycobacteria. The similarities of these models to granulomas encountered in clinical specimens include cellular composition, granulomas' cytokine production, and cell surface antigens. A reliable in vitro dormancy model may serve as a useful platform to test whether drug candidates can kill dormant mycobacteria. Novel drugs that target dormancy-specific pathways may shorten the current long, difficult treatments necessary to cure mycobacterial diseases.
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23
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Smith RL, Schukken YH, Lu Z, Mitchell RM, Grohn YT. Development of a model to simulate infection dynamics of Mycobacterium bovis in cattle herds in the United States. J Am Vet Med Assoc 2014; 243:411-23. [PMID: 23865885 DOI: 10.2460/javma.243.3.411] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To develop a mathematical model to simulate infection dynamics of Mycobacterium bovis in cattle herds in the United States and predict efficacy of the current national control strategy for tuberculosis in cattle. DESIGN Stochastic simulation model. SAMPLE Theoretical cattle herds in the United States. PROCEDURES A model of within-herd M bovis transmission dynamics following introduction of 1 latently infected cow was developed. Frequency- and density-dependent transmission modes and 3 tuberculin test-based culling strategies (no test-based culling, constant [annual] testing with test-based culling, and the current strategy of slaughterhouse detection-based testing and culling) were investigated. Results were evaluated for 3 herd sizes over a 10-year period and validated via simulation of known outbreaks of M bovis infection. RESULTS On the basis of 1,000 simulations (1,000 herds each) at replacement rates typical for dairy cattle (0.33/y), median time to detection of M bovis infection in medium-sized herds (276 adult cattle) via slaughterhouse surveillance was 27 months after introduction, and 58% of these herds would spontaneously clear the infection prior to that time. Sixty-two percent of medium-sized herds without intervention and 99% of those managed with constant test-based culling were predicted to clear infection < 10 years after introduction. The model predicted observed outbreaks best for frequency-dependent transmission, and probability of clearance was most sensitive to replacement rate. CONCLUSIONS AND CLINICAL RELEVANCE Although modeling indicated the current national control strategy was sufficient for elimination of M bovis infection from dairy herds after detection, slaughterhouse surveillance was not sufficient to detect M bovis infection in all herds and resulted in subjectively delayed detection, compared with the constant testing method. Further research is required to economically optimize this strategy.
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Affiliation(s)
- Rebecca L Smith
- Section of Epidemiology, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
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24
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Álvarez J, Perez A, Marqués S, Bezos J, Grau A, de la Cruz ML, Romero B, Saez JL, del Rosario Esquivel M, Martínez MDC, Mínguez O, de Juan L, Domínguez L. Risk factors associated with negative in-vivo diagnostic results in bovine tuberculosis-infected cattle in Spain. BMC Vet Res 2014; 10:14. [PMID: 24410926 PMCID: PMC3895706 DOI: 10.1186/1746-6148-10-14] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 01/03/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Despite great effort and investment incurred over decades to control bovine tuberculosis (bTB), it is still one of the most important zoonotic diseases in many areas of the world. Test-and-slaughter strategies, the basis of most bTB eradication programs carried out worldwide, have demonstrated its usefulness in the control of the disease. However, in certain countries, eradication has not been achieved due in part to limitations of currently available diagnostic tests. In this study, results of in-vivo and post-mortem diagnostic tests performed on 3,614 animals from 152 bTB-infected cattle herds (beef, dairy, and bullfighting) detected in 2007-2010 in the region of Castilla y León, Spain, were analyzed to identify factors associated with positive bacteriological results in cattle that were non-reactors to the single intradermal tuberculin test, to the interferon-gamma (IFN-γ) assay, or to both tests applied in parallel (Test negative/Culture + animals, T-/C+). The association of individual factors (age, productive type, and number of herd-tests performed since the disclosure of the outbreak) with the bacteriology outcome (positive/negative) was analyzed using a mixed multivariate logistic regression model. RESULTS The proportion of non-reactors with a positive post-mortem result ranged from 24.3% in the case of the SIT test to 12.9% (IFN-γ with 0.05 threshold) and 11.9% (95% CI 9.9-11.4%) using both tests in parallel. Older (>4.5 years) and bullfighting cattle were associated with increased odds of confirmed bTB infection by bacteriology, whereas dairy cattle showed a significantly lower risk. Ancillary use of IFN-γ assay reduced the proportion of T-/C + animals in high risk groups. CONCLUSIONS These results demonstrate the likelihood of positive bacteriological results in non-reactor cattle is influenced by individual epidemiological factors of tested animals. Increased surveillance on non-reactors with an increased probability of being false negative could be helpful to avoid bTB persistence, particularly in chronically infected herds. These findings may aid in the development of effective strategies for eradication of bTB in Spain.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Lucía de Juan
- Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Universidad Complutense Madrid, 28040 Madrid, Spain.
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25
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Brooks-Pollock E, Conlan AJK, Mitchell AP, Blackwell R, McKinley TJ, Wood JLN. Age-dependent patterns of bovine tuberculosis in cattle. Vet Res 2013; 44:97. [PMID: 24131703 PMCID: PMC3853322 DOI: 10.1186/1297-9716-44-97] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 09/30/2013] [Indexed: 11/10/2022] Open
Abstract
Bovine tuberculosis (BTB) is an important livestock disease, seriously impacting cattle industries in both industrialised and pre-industrialised countries. Like TB in other mammals, infection is life long and, if undiagnosed, may progress to disease years after exposure. The risk of disease in humans is highly age-dependent, however in cattle, age-dependent risks have yet to be quantified, largely due to insufficient data and limited diagnostics. Here, we estimate age-specific reactor rates in Great Britain by combining herd-level testing data with spatial movement data from the Cattle Tracing System (CTS). Using a catalytic model, we find strong age dependencies in infection risk and that the probability of detecting infection increases with age. Between 2004 and 2009, infection incidence in cattle fluctuated around 1%. Age-specific incidence increased monotonically until 24-36 months, with cattle aged between 12 and 36 months experiencing the highest rates of infection. Beef and dairy cattle under 24 months experienced similar infection risks, however major differences occurred in older ages. The average reproductive number in cattle was greater than 1 for the years 2004-2009. These methods reveal a consistent pattern of BTB rates with age, across different population structures and testing patterns. The results provide practical insights into BTB epidemiology and control, suggesting that targeting a mass control programme at cattle between 12 and 36 months could be beneficial.
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Affiliation(s)
- Ellen Brooks-Pollock
- Disease Dynamics Unit, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK.
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26
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Mycobacterial Etiology of Pulmonary Tuberculosis and Association with HIV Infection and Multidrug Resistance in Northern Nigeria. Tuberc Res Treat 2013; 2013:650561. [PMID: 23970967 PMCID: PMC3730141 DOI: 10.1155/2013/650561] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 06/19/2013] [Indexed: 11/24/2022] Open
Abstract
Objective. Data on pulmonary tuberculosis (TB) caused by Mycobacterium tuberculosis (MTB) complex in Nigeria are limited. We investigated species of MTB complex in TB cases from northern Nigeria. Methods. New TB suspects were enrolled, screened for HIV and their sputum samples were cultured after routine microscopy. Genotypes MTBC and MTBDRplus were used to characterize the MTB complex species and their resistance to isoniazid and rifampicin.
Results. Of the 1,603 patients enrolled, 375 (23%) had MTB complex infection: 354 (94.4%) had Mycobacterium tuberculosis; 20 (5.3%) had Mycobacterium africanum; and one had Mycobacterium bovis (0.3%). Cases were more likely to be male (AOR = 1.87, 95% CI : 1.42–2.46; P ≤ 0.001), young (AOR = 2.03, 95% CI : 1.56–2.65; P ≤ 0.001) and have HIV (AOR = 1.43, 95% CI : 1.06–1.92; P = 0.032). In 23 patients (6.1%), the mycobacterium was resistant to at least one drug, and these cases were more likely to have HIV and prior TB treatment (AOR = 3.62, 95% CI : 1.51–8.84; P = 0.004; AOR : 4.43; 95% CI : 1.71–11.45 P = 0.002 resp.), compared to cases without any resistance. Conclusion. Mycobacterium tuberculosis remained the predominant specie in TB in this setting followed by Mycobacterium africanum while Mycobacterium bovis was rare. The association of TB drug resistance with HIV has implications for TB treatment.
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Arega SM, Conraths FJ, Ameni G. Prevalence of tuberculosis in pigs slaughtered at two abattoirs in Ethiopia and molecular characterization of Mycobacterium tuberculosis isolated from tuberculous-like lesions in pigs. BMC Vet Res 2013; 9:97. [PMID: 23647845 PMCID: PMC3661388 DOI: 10.1186/1746-6148-9-97] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 04/24/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tuberculosis (TB) is an infectious, granulomatous disease caused by acid-fast bacilli of the genus Mycobacterium. The disease affects practically all species of vertebrates. Although mammalian tuberculosis has been nearly controlled in many developed countries, it is still a serious problem in humans and domestic animals including pigs in developing countries. In Ethiopia, the prevalence of TB in pigs is not known. Therefore, this study was designed to estimate the prevalence of TB in pigs in central Ethiopia and to characterize the causative agents using molecular techniques. RESULTS The estimated prevalence of TB was 5.8% (49/841). Age and origin of pigs were significantly associated (P<0.001) with the prevalence. In contrast, an association of sex, floor type and water source with the prevalence could not be shown. Culture positivity was confirmed in 30.6% (15/49) of the tuberculous-like lesions. Of the 15 isolates, 12 were acid fast positive while five of the latter were confirmed by multiplex PCR as members of the M. tuberculosis complex. Speciation of the five isolates further confirmed that they were M. tuberculosis, belonging to SIT1088 (two isolates) and SIT1195 (one isolate). The remaining two isolates belong to an identical spoligotype, the pattern of which was not found in the spoligotype database (SpolDB4). CONCLUSIONS The isolation of M. tuberculosis from pigs suggests a possible risk of transmission between humans and pigs. Hence, establishing feasible control methods is required.
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Affiliation(s)
- Sintayehu Mulugeta Arega
- Department of Veterinary Clinical Medicine, Faculty of Veterinary Medicine, University of Gondar, PO Box 196, Gondar, Ethiopia.
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28
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Muwonge A, Johansen TB, Vigdis E, Godfroid J, Olea-Popelka F, Biffa D, Skjerve E, Djønne B. Mycobacterium bovis infections in slaughter pigs in Mubende district, Uganda: a public health concern. BMC Vet Res 2012; 8:168. [PMID: 22999303 PMCID: PMC3526550 DOI: 10.1186/1746-6148-8-168] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 09/17/2012] [Indexed: 11/10/2022] Open
Abstract
Background Bovine tuberculosis (TB) caused by Mycobacterium bovis is primarily a disease of ruminants, particularly cattle (Bos primigenius) and buffalo (Syncerus caffer), and is endemic in most developing countries. To date, studies done in Uganda have documented the prevalence of M. bovis in cattle, humans and wild life, in addition to non-tuberculous mycobacteria in pigs. Pigs are increasingly becoming an important component of the livestock sector and share the human ecosystem in rural Uganda. It is therefore of public health interest that they are not a source of human infections. As a follow up to previously published findings on mycobacteria in pigs, this study was aimed at investigating the occurrence and molecular characteristics of M. bovis detected in slaughter pigs in Mubende district, Uganda. One hundred fifty mesenteric lymph nodes with lesions suggestive of mycobacterial infections were collected from approximately one thousand slaughtered pigs in Mubende district over a period of five months. The isolation and identification of M. bovis was done using conventional mycobacteriological methods. Mycobacteria belonging to the Mycobacterium tuberculosis complex (MTC) were identified to species level using deletion analysis. Molecular typing was done using Spoligotyping and MIRU-VNTR analysis. Molecular data were analysed and interpreted using MIRU-VNTR plus, SpolDB4.0 and the Mycobacterium bovis spoligo database. Results Of the examined animals, one boar and two sows from Madudu Sub County were infected with M. bovis which presented as lesions of a deep yellow colour and a grit-like texture in the mesenteric lymph nodes. This represents 2% (3/150) of the lymph nodes where lesions suggestive of mycobacterial infections were detected. Molecular analysis revealed that the isolates from the infected pigs showed identical MIRU-VNTR profile and spoligotype (SB1469). Conclusions This is the first study documenting the occurrence of M. bovis in slaughter pigs in Uganda, revealing that one in fifty slaughter pigs with suspected lesions in mesenteric lymph nodes were infected. Molecular analysis revealed that the isolates were identical, showing a spoligotype previously reported from humans and cattle in the north eastern part of the Uganda cattle corridor. This finding is of public health importance, therefore there is a need for close cooperation between medical and veterinary professionals in designing and implementing control and prevention measures that safeguard the public from this potential source of zoonotic TB in Uganda.
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Affiliation(s)
- Adrian Muwonge
- Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, P.O. Box 8146, Dep., 0033, Oslo, Norway.
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29
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Alvarez J, Perez AM, Bezos J, Casal C, Romero B, Rodriguez-Campos S, Saez-Llorente JL, Diaz R, Carpintero J, de Juan L, Domínguez L. Eradication of bovine tuberculosis at a herd-level in Madrid, Spain: study of within-herd transmission dynamics over a 12 year period. BMC Vet Res 2012; 8:100. [PMID: 22748007 PMCID: PMC3464814 DOI: 10.1186/1746-6148-8-100] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 06/29/2012] [Indexed: 12/02/2022] Open
Abstract
Background Eradication of bovine tuberculosis (bTB) through the application of test-and-cull programs is a declared goal of developed countries in which the disease is still endemic. Here, longitudinal data from more than 1,700 cattle herds tested during a 12 year-period in the eradication program in the region of Madrid, Spain, were analyzed to quantify the within-herd transmission coefficient (β) depending on the herd-type (beef/dairy/bullfighting). In addition, the probability to recover the officially bTB free (OTF) status in infected herds depending on the type of herd and the diagnostic strategy implemented was assessed using Cox proportional hazard models. Results Overall, dairy herds showed higher β (median 4.7) than beef or bullfighting herds (2.3 and 2.2 respectively). Introduction of interferon-gamma (IFN-γ) as an ancillary test produced an apparent increase in the β coefficient regardless of production type, likely due to an increase in diagnostic sensitivity. Time to recover OTF status was also significantly lower in dairy herds, and length of bTB episodes was significantly reduced when the IFN-γ was implemented to manage the outbreak. Conclusions Our results suggest that bTB spreads more rapidly in dairy herds compared to other herd types, a likely cause being management and demographic-related factors. However, outbreaks in dairy herds can be controlled more rapidly than in typically extensive herd types. Finally, IFN-γ proved its usefulness to rapidly eradicate bTB at a herd-level.
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Affiliation(s)
- Julio Alvarez
- Instituto de Investigación en Recursos Cinegéticos IREC (CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13071, Ciudad Real, Spain
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30
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Vial F, Johnston WT, Donnelly CA. Local cattle and badger populations affect the risk of confirmed tuberculosis in British cattle herds. PLoS One 2011; 6:e18058. [PMID: 21464920 PMCID: PMC3065452 DOI: 10.1371/journal.pone.0018058] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Accepted: 02/20/2011] [Indexed: 11/18/2022] Open
Abstract
Background The control of bovine tuberculosis (bTB) remains a priority on the public health agenda in Great Britain, after launching in 1998 the Randomised Badger Culling Trial (RBCT) to evaluate the effectiveness of badger (Meles meles) culling as a control strategy. Our study complements previous analyses of the RBCT data (focusing on treatment effects) by presenting analyses of herd-level risks factors associated with the probability of a confirmed bTB breakdown in herds within each treatment: repeated widespread proactive culling, localized reactive culling and no culling (survey-only). Methodology/Principal Findings New cases of bTB breakdowns were monitored inside the RBCT areas from the end of the first proactive badger cull to one year after the last proactive cull. The risk of a herd bTB breakdown was modeled using logistic regression and proportional hazard models adjusting for local farm-level risk factors. Inside survey-only and reactive areas, increased numbers of active badger setts and cattle herds within 1500 m of a farm were associated with an increased bTB risk. Inside proactive areas, the number of M. bovis positive badgers initially culled within 1500 m of a farm was the strongest predictor of the risk of a confirmed bTB breakdown. Conclusions/Significance The use of herd-based models provide insights into how local cattle and badger populations affect the bTB breakdown risks of individual cattle herds in the absence of and in the presence of badger culling. These measures of local bTB risks could be integrated into a risk-based herd testing programme to improve the targeting of interventions aimed at reducing the risks of bTB transmission.
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Affiliation(s)
- Flavie Vial
- Department of Infectious Disease Epidemiology, MRC Centre for Outbreak Analysis and Modelling, School of Public Health, Imperial College London, London, United Kingdom
- * E-mail:
| | | | - Christl A. Donnelly
- Department of Infectious Disease Epidemiology, MRC Centre for Outbreak Analysis and Modelling, School of Public Health, Imperial College London, London, United Kingdom
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Pathology of camel tuberculosis and molecular characterization of its causative agents in pastoral regions of Ethiopia. PLoS One 2011; 6:e15862. [PMID: 21283668 PMCID: PMC3025912 DOI: 10.1371/journal.pone.0015862] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 11/25/2010] [Indexed: 01/31/2023] Open
Abstract
A cross sectional study was conducted on 906 apparently healthy camels slaughtered at Akaki and Metehara abattoirs to investigate the pathology of camel tuberculosis (TB) and characterize its causative agents using postmortem examination, mycobacteriological culturing, and multiplex polymerase chain reaction (PCR), region of difference-4 (RD4)-based PCR and spoligotyping. The prevalence of camel TB was 10.04% (91/906) on the basis of pathology and it was significantly higher in females (χ2 = 4.789; P = 0.029). The tropism of TB lesions was significantly different among the lymph nodes (χ2 = 22.697; P = 0.002) and lung lobes (χ2 = 17.901; P = 0.006). Mycobacterial growth was observed in 34% (31/91) of camels with grossly suspicious TB lesions. Upon further molecular characterization using multiplex PCR, 68% (21/31) of the colonies showed a positive signal for the genus Mycobacterium, of which two were confirmed Mycobacterium bovis (M. bovis) by RD4 deletion typing. Further characterization of the two M. bovis at strains level revealed that one of the strains was SB0133 while the other strain was new and had not been reported to the M. bovis database prior to this study. Hence, it has now been reported to the database, and designated as SB1953. In conclusion, the results of the present study have shown that the majority of camel TB lesions are caused by mycobacteria other than Mycobacterium tuberculosis complex. And hence further identification and characterization of these species would be useful towards the efforts made to control TB in camels.
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New assessment of bovine tuberculosis risk factors in Belgium based on nationwide molecular epidemiology. J Clin Microbiol 2010; 48:2802-8. [PMID: 20573869 DOI: 10.1128/jcm.00293-10] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
This assessment aimed to elaborate a statistical nationwide model for analyzing the space-time dynamics of bovine tuberculosis in search of potential risk factors that could be used to better target surveillance measures. A database comprising Mycobacterium bovis molecular profiles from all isolates obtained from Belgian outbreaks during the 1995-to-2006 period (n = 415) allowed the identification of a predominant spoligotype (SB0162). Various databases compiling 49 parameters to be tested were queried using a multiple stepwise logistic regression to assess bovine tuberculosis risk factors. Two isolate datasets were analyzed: the first included all Mycobacterium bovis isolates, while the second included only data related to the SB0162 type strain. When all Mycobacterium bovis isolates were included in the model, several risk factors were identified: history of bovine tuberculosis in the herd (P < 0.001), proximity of an outbreak (P < 0.001), cattle density (P < 0.001), and annual amplitude of mean middle-infrared temperature (P < 0.001). The approach restricted to the predominant SB0162 type strain additionally highlighted the proportion of movements from an infected area during the current year as a main risk factor (P = 0.009). This study identified several risk factors for bovine tuberculosis in cattle, highlighted the usefulness of molecular typing in the study of bovine tuberculosis epidemiology, and suggests a difference of behavior for the predominant type strain. It also emphasizes the role of animals' movements in the transmission of the disease and supports the importance of controlling trade movements.
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Humblet MF, Boschiroli ML, Saegerman C. Classification of worldwide bovine tuberculosis risk factors in cattle: a stratified approach. Vet Res 2009; 40:50. [PMID: 19497258 PMCID: PMC2710499 DOI: 10.1051/vetres/2009033] [Citation(s) in RCA: 180] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Accepted: 06/04/2009] [Indexed: 11/28/2022] Open
Abstract
The worldwide status of bovine tuberculosis (bTB) as a zoonosis remains of great concern. This article reviews the main risk factors for bTB in cattle based on a three-level classification: animal, herd and region/country level. A distinction is also made, whenever possible, between situations in developed and developing countries as the difference of context might have consequences in terms of risk of bTB. Recommendations are suggested to animal health professionals and scientists directly involved in the control and prevention of bTB in cattle. The determination of Millenium Development Goals for bTB is proposed to improve the control/eradication of the disease worldwide.
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Affiliation(s)
- Marie-France Humblet
- Research Unit in Epidemiology and Risk Analysis applied to Veterinary Sciences, Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Liège, B42, Boulevard de Colonster 20, 4000 Liège-Sart Tilman, Belgium
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Tschopp R, Schelling E, Hattendorf J, Aseffa A, Zinsstag J. Risk factors of bovine tuberculosis in cattle in rural livestock production systems of Ethiopia. Prev Vet Med 2009; 89:205-11. [PMID: 19339066 PMCID: PMC2706391 DOI: 10.1016/j.prevetmed.2009.02.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2008] [Revised: 01/12/2009] [Accepted: 02/07/2009] [Indexed: 11/13/2022]
Abstract
This study shows a representative stratified cluster sample survey of the prevalence of comparative intradermal tuberculin test in cattle from four regions in Ethiopia. Using a cut-off for positivity of 2 mm, it assesses possible risk factors for tuberculin-positive reaction in cattle. Seventy-three villages in 24 kebeles (administrative units) were randomly selected, from which 2216 cattle from 780 owners were tested. In addition, 450 of these cattle owners were interviewed for risk factor assessment. Ninety-nine percent of the tested cattle in this rural livestock production system were traditional zebus. The individual overall prevalence of cattle bovine tuberculosis (BTB)e was 3%, with the highest found in Meskan Mareko, in Central Ethiopia (7.9%) and the lowest in Woldia, in the North East edge of the Rift Valley (1.2%). Generalised Linear Mixed Models (GLMM) with random effect on kebeles was used to analyse risk factors of cattle reactors and human tuberculosis (TB) infection. Purchase of cattle and presence of other livestock in the herd were statistically significant, with OR: 1.7, p-values of 0.03 and OR: 2, p = 0.05, respectively. Family members diagnosed with TB or showing clinical signs of extra-pulmonary TB (EPTB) were reported in 86 households (19%). None of the assessed potential risk factors of disease transmission between cattle and human (food consumption, livestock husbandry and presence of BTB-positive cattle) were statistically significant.
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Affiliation(s)
- Rea Tschopp
- Swiss Tropical Institute, PO Box, CH-4002 Basel, Switzerland.
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Alvarez AH, Estrada-Chávez C, Flores-Valdez MA. Molecular findings and approaches spotlighting Mycobacterium bovis persistence in cattle. Vet Res 2009; 40:22. [PMID: 19220975 PMCID: PMC2695034 DOI: 10.1051/vetres/2009005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2008] [Accepted: 02/11/2009] [Indexed: 11/20/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) and Mycobacterium bovis (M. bovis) are the etiological agents of human and bovine tuberculosis (TB, bTB) respectively, and share genetic identity over 99% at the whole genome level. Progress has been made towards explaining how mycobacteria and their infected hosts remain in balance without producing clinical symptoms of disease, a phenomenon referred to as latency or persistence, which can be mimicked by certain in vitro conditions. Latency/persistence has mainly been studied using Mtb, where the two-component signalling system, dosRS, has been assigned an instrumental role, and even constitutes the current basis for development of new diagnostic methods and treatment addressing this particular stage of TB. M. bovis conserves homolog genes that in Mtb play a role in human latent TB infection and that, by analogy, would allow it to enter a persistent state in infected cattle; nevertheless, little attention has been paid to this stage in bovine hosts. We suggest that many of the advances acquired through the study of Mtb can and should be taken into consideration by research groups and veterinary professionals dealing with bTB. The study of the infection in bovines, paying particular attention to defining the molecular and cellular markers of a M. bovis persistent infection in cattle, presents great opportunities for the development and trial of new diagnostic tests and vaccines, tools that will surely help in promoting eradication of bTB in high-burden settings.
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Affiliation(s)
- Angel H Alvarez
- Centro de Investigación y Asistencía en Tecnologá y diseño del Estado de Jalisco (CIATEJ) A.C., Unidad de Biotecnología, Guadalajara, Jalisco, C.P. 44270, México
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Serrano-Moreno BA, Romero TA, Arriaga C, Torres RA, Pereira-Suárez AL, García-Salazar JA, Estrada-Chávez C. High frequency of Mycobacterium bovis DNA in colostra from tuberculous cattle detected by nested PCR. Zoonoses Public Health 2008; 55:258-66. [PMID: 18454747 DOI: 10.1111/j.1863-2378.2008.01125.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We evaluated by nested PCR reaction, different cow secretions from a herd with 48% of prevalence of bovine tuberculosis (BTB), seeking to determine niches where Mycobacterium bovis could be found. Postmortem examination of 18 (75%) tuberculin reacting cows allowed demonstrates BTB-compatible lesions in six, all of them PCR positives in milk and four in colostra samples. Our results showed that up to 62% of the colostra analysed contained M. bovis DNA, whereas only 18% of milk gave a positive reaction. Moreover, in bronchoalveolar lavages from cattle with compatible lesions in lungs or lymph nodes, where macrophages account up to 90% of cells, we did not find evidences of M. bovis. Altogether, these results suggest that differences in the anti-bacterial capacity of bovine macrophages, dependent upon microenvironment and organ-specific factors, exist. Alternatively, we hypothesize that hypoxic conditions that are encountered in mammary glands macrophages could induce M. bovis entrance into a 'dormancy-like' state, and that the high number of colostra samples were M. bovis was detected, could be an indicator of reactivation during 'peripartum'.
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Affiliation(s)
- B A Serrano-Moreno
- Facultad de Estudios Superiores-Cuautitlán, Universidad Nacional Autonoma de Mexico (UNAM), Estado de México, Mexico
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Green DM, Kiss IZ, Mitchell AP, Kao RR. Estimates for local and movement-based transmission of bovine tuberculosis in British cattle. Proc Biol Sci 2008; 275:1001-5. [PMID: 18252669 PMCID: PMC2366193 DOI: 10.1098/rspb.2007.1601] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Both badgers and livestock movements have been implicated in contributing to the ongoing epidemic of bovine tuberculosis (BTB) in British cattle. However, the relative contributions of these and other causes are not well quantified. We used cattle movement data to construct an individual (premises)-based model of BTB spread within Great Britain, accounting for spread due to recorded cattle movements and other causes. Outbreak data for 2004 were best explained by a model attributing 16% of herd infections directly to cattle movements, and a further 9% unexplained, potentially including spread from unrecorded movements. The best-fit model assumed low levels of cattle-to-cattle transmission. The remaining 75% of infection was attributed to local effects within specific high-risk areas. Annual and biennial testing is mandatory for herds deemed at high risk of infection, as is pre-movement testing from such herds. The herds identified as high risk in 2004 by our model are in broad agreement with those officially designated as such at that time. However, border areas at the edges of high-risk regions are different, suggesting possible areas that should be targeted to prevent further geographical spread of disease. With these areas expanding rapidly over the last decade, their close surveillance is important to both identify infected herds quickly, and limit their further growth.
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Affiliation(s)
- Darren M Green
- Institute of Aquaculture, University of Stirling, Stirling, Stirlingshire, UK
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Ameni G, Aseffa A, Engers H, Young D, Gordon S, Hewinson G, Vordermeier M. High prevalence and increased severity of pathology of bovine tuberculosis in Holsteins compared to zebu breeds under field cattle husbandry in central Ethiopia. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2007; 14:1356-61. [PMID: 17761523 PMCID: PMC2168113 DOI: 10.1128/cvi.00205-07] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A comparative study on the prevalence and pathology of bovine tuberculosis (TB) was conducted on 5,424 cattle (2,578 zebus, 1,921 crosses, and 925 Holsteins), which were kept on pasture in the central highlands of Ethiopia, using a comparative intradermal tuberculin test, postmortem examination, and bacteriology. The overall prevalence of bovine TB was 13.5%; prevalence was higher in Holsteins than either zebus (22.2% versus 11.6%, chi(2) = 61.8; P < 0.001) or crosses (22.2% versus 11.9%, chi(2) = 50.7; P < 0.001). Moreover, the severity of pathology in Holsteins (mean +/- standard error of the mean [SEM], 6.84 +/- 0.79) was significantly higher (P = 0.018) than the severity of pathology in zebus (5.21 +/- 0.30). In addition, the risk of TB in Holsteins was more than twice (odds ratio [OR] = 2.32; 95% confidence interval [CI] = 1.89, 2.85) that in zebus. Animals between 5 and 9 years of age were at higher (OR = 2.37; 95% CI = 1.80, 3.12) risk of bovine TB than those 2 years of age or below. A significant difference (chi(2) = 351; P < 0.001) in the occurrence of TB lesions in lymph nodes was recorded; the mesenteric lymph node (mean pathology score +/- SEM, 1.95 +/- 0.08) was most severely affected, followed by the retropharyngeal (0.80 +/- 0.05) and caudal mediastinal (0.8 +/- 0.06) lymph nodes. Fifty-six percent (n = 145) of the animals with gross TB lesions were culture positive; the lowest culture positivity was recorded in the skin lesions (27.3%) and the lesions of the mesenteric lymph node (31.5%). Both the skin test response and the postmortem findings suggested a higher susceptibility to bovine TB in Holsteins than zebus under identical field husbandry conditions (on pasture). In the light of increased numbers of Holstein cattle introduced into this area to raise milk production to satisfy the needs of Addis Ababa's growing population, these findings highlight the need for a control program in these herds.
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Affiliation(s)
- Gobena Ameni
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.
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Kao RR, Gravenor MB, Charleston B, Hope JC, Martin M, Howard CJ. Mycobacterium bovis shedding patterns from experimentally infected calves and the effect of concurrent infection with bovine viral diarrhoea virus. J R Soc Interface 2007; 4:545-51. [PMID: 17251130 PMCID: PMC1871617 DOI: 10.1098/rsif.2006.0190] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Concurrent infection of cattle with bovine viral diarrhoea virus (BVDV) and Mycobacterium bovis is considered to be a possible risk factor for onward transmission of bovine tuberculosis (BTB) in infected cattle and is known to compromise diagnostic tests. A comparison is made here of M. bovis shedding (i.e. release) characteristics from 12 calves, six experimentally co-infected with BVDV and six infected with M. bovis alone, using simple models of bacterial replication. These statistical and mathematical models account for the intermittent or episodic nature of shedding, the dynamics of within-host bacterial proliferation and the sampling distribution from a given shedding episode. We show that while there are distinct differences among the shedding patterns of calves given the same infecting dose, there is no statistically significant difference between the two groups of calves. Such differences as there are, can be explained solely in terms of the shedding frequency, but with all calves potentially excreting the same amount of bacteria in a given shedding episode post-infection. The model can be thought of as a process of the bacteria becoming established in a number of discrete foci of colonization, rather than as a more generalized infection of the respiratory tract. In this case, the variability in the shedding patterns of the infected calves can be explained solely by differences in the number of foci established and shedding being from individual foci over time. Should maximum exposure on a particular occasion be a critical consideration for cattle-to-cattle transmission of BTB, cattle that shed only intermittently may still make an important contribution to the spread and persistence of the disease.
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Affiliation(s)
- R R Kao
- Department of Zoology, University of Oxford, South Parks Road, Oxford, UK.
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Renwick AR, White PCL, Bengis RG. Bovine tuberculosis in southern African wildlife: a multi-species host-pathogen system. Epidemiol Infect 2007; 135:529-40. [PMID: 16959052 PMCID: PMC2870607 DOI: 10.1017/s0950268806007205] [Citation(s) in RCA: 148] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/14/2006] [Indexed: 11/06/2022] Open
Abstract
This review examines the current situation of bovine tuberculosis (bTB) in southern African savannah systems, and uses theory on multi-species host-pathogen systems to suggest possible options for future research and management. In southern Africa, the buffalo (Syncerus caffer) and the Kafue lechwe [Marsh antelope] (Kobus leche) have been found to be maintenance hosts for this disease, but the importance of other host species is becoming apparent. The role of other host species in the maintenance and spread of the disease varies, depending on the spatial distribution and resource utilization patterns of the species, disease susceptibility, transmission modes and the ecology of both host(s) and vector(s). Future research needs to identify the pathogenicity of bTB in each of the host species, and the mechanisms and rates of inter- and intra-specific transmission among different species, in order to develop multi-host models to understand the development and spread of the disease.
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Affiliation(s)
- A R Renwick
- Environment Department, University of York, York, UK
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