1
|
Lakew M, Tadesse B, Srinivasan S, Aschalew M, Andarge B, Kebede D, Etifu A, Alemu T, Yalew B, Benti T, Olani A, Abera S, Bedada W, Fromsa A, Mekonnen GA, Almaw G, Ameni G, Ashenafi H, Gumi B, Bakker D, Kapur V. Assessing the feasibility of test-and-cull and test-and-segregation approaches for the control of high-prevalence bovine tuberculosis in Ethiopian intensive dairy farms. Sci Rep 2024; 14:14298. [PMID: 38906922 PMCID: PMC11192749 DOI: 10.1038/s41598-024-64884-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 06/13/2024] [Indexed: 06/23/2024] Open
Abstract
Bovine tuberculosis (bTB) is endemic and has a substantial impact on the livestock sector in Ethiopia and other low and middle-income countries (LMICs). With a national emphasis on dairy farm intensification to boost milk production and spur economic growth, the incidence of bTB is anticipated to rise. However, Ethiopia, like other LMICs, lacks a comprehensive national bTB control strategy due to the economic and social infeasibility of traditional test-and-cull (TC) approaches. To inform the development of such a strategy, we evaluated the effectiveness and feasibility of TC and test-and-segregation (TSg) strategies for bTB control on Ethiopian dairy farms. A TC approach was used at Farm A [N = 62; comparative cervical test (CCT) > 4 mm, starting prevalence 11.3%] while TSg was implemented at Farm B (N = 45; CCT > 4 mm, prevalence 22.2%), with testing intervals of 2-4 months. Both strategies achieved a reduction in bTB prevalence to 0%, requiring seven rounds of TC over 18 months at Farm A, and five rounds of TSg over 12 months at Farm B's negative herd. The results show that adopting more sensitive thresholds [CCT > 0 mm or single cervical test (SCT) > 2 mm] during later rounds was pivotal in identifying and managing previously undetected infections, emphasizing the critical need for optimized diagnostic thresholds. Cost analysis revealed that TC was approximately twice as expensive as TSg, primarily due to testing, labor, and cow losses in TC, versus construction of new facilities and additional labor for TSg. This underscores the economic and logistical challenges of bTB management in resource-limited settings. Taken together, our study highlights an urgent need for the exploration of alternative approaches including TSg and or vaccination to mitigate within herd transmission and enable implementation of bTB control in regions where TC is not feasible.
Collapse
Affiliation(s)
- Matios Lakew
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia.
- Animal Health Institute, P.O. Box 04, Sebeta, Ethiopia.
| | | | | | | | | | | | | | | | - Bekele Yalew
- Animal Health Institute, P.O. Box 04, Sebeta, Ethiopia
| | - Teferi Benti
- Animal Health Institute, P.O. Box 04, Sebeta, Ethiopia
| | - Abebe Olani
- Animal Health Institute, P.O. Box 04, Sebeta, Ethiopia
| | - Shubisa Abera
- Animal Health Institute, P.O. Box 04, Sebeta, Ethiopia
| | - Wegene Bedada
- Animal Health Institute, P.O. Box 04, Sebeta, Ethiopia
| | - Abebe Fromsa
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
| | | | - Gizat Almaw
- Animal Health Institute, P.O. Box 04, Sebeta, Ethiopia
| | - Gobena Ameni
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
- Department of Veterinary Medicine, College of Agriculture and Veterinary Medicine, United Arab Emirates University, PO Box 15551, Al Ain, United Arab Emirates
| | - Hagos Ashenafi
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
| | - Balako Gumi
- Aklilu Lemma Institute of Pathobiology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
| | - Douwe Bakker
- Independent Researcher and Technical Consultant, Lelystad, The Netherlands.
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain.
| | - Vivek Kapur
- Department of Animal Science, The Pennsylvania State University, University Park, PA, USA.
- Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA.
| |
Collapse
|
2
|
Vera-Salmoral E, Sánchez-Carvajal JM, Gómez-Gascón L, Larenas-Muñoz F, Tarradas C, Gómez-Laguna J, Huerta B. Assessment of the diagnostic performance of intradermal tuberculin test and post-mortem inspection for the diagnosis of bovine tuberculosis according to WOAH guidelines. Res Vet Sci 2024; 168:105159. [PMID: 38266351 DOI: 10.1016/j.rvsc.2024.105159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 01/17/2024] [Accepted: 01/19/2024] [Indexed: 01/26/2024]
Abstract
Bovine tuberculosis (bTB) constitutes a global challenge for public and animal health with still some deficiencies regarding its diagnosis. This study aimed to estimate the accuracy of the single intradermal tuberculin test (SIT) and post-mortem inspection for different diagnostic objectives following WOAH guidelines. Tissue samples from 59 microbiological culture/PCR-positive and 58 microbiological culture/PCR-negative cattle were evaluated. The diagnostic sensitivity and specificity, the positive and negative probability indices as well as the positive and negative predictive values (PPV and NPV) of each technique were estimated for different pretest probabilities. The SIT with strict interpretation demonstrated moderate precision in confirming the absence of infection in populations historically free of bTB, with a 12.1% rate of false positives, but also detecting positive animals in the early stage of the eradication programs, with a 13.6% rate of false negatives. The diagnostic performance for ruling out bTB was notably high (NPV > 90%) in animals with a pre-test probability (PTP) below 42%. Post-mortem inspection constituted an interesting alternative tool to confirm suspected and positive cases for SIT, particularly in areas with bTB prevalence exceeding 19%, where implementing SIT and eradication measures may be impractical. In these areas, the likelihood that animals with tuberculosis-like lesions are affected by the disease surpasses 90%. Similarly, in herds with a PTP below 25%, the absence of bTB could be confidently ruled out with over 90% certainty. These findings highlight the effectiveness of SIT and post-mortem inspection as valuable techniques for current eradication programs and controlling bTB in high-prevalence areas where molecular techniques may not be feasible.
Collapse
Affiliation(s)
- Eduardo Vera-Salmoral
- Department of Animal Health, UIC Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, International Excellence Agrifood Campus 'CeiA3', University of Córdoba, 14014 Córdoba, Spain; Department of Anatomy and Comparative Pathology and Toxicology, Pathology and Immunology Group (UCO-PIG), UIC Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, International Excellence Agrifood Campus 'CeiA3', 14014 Córdoba, Spain
| | - José María Sánchez-Carvajal
- Department of Anatomy and Comparative Pathology and Toxicology, Pathology and Immunology Group (UCO-PIG), UIC Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, International Excellence Agrifood Campus 'CeiA3', 14014 Córdoba, Spain.
| | - Lidia Gómez-Gascón
- Department of Animal Health, UIC Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, International Excellence Agrifood Campus 'CeiA3', University of Córdoba, 14014 Córdoba, Spain
| | - Fernanda Larenas-Muñoz
- Department of Anatomy and Comparative Pathology and Toxicology, Pathology and Immunology Group (UCO-PIG), UIC Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, International Excellence Agrifood Campus 'CeiA3', 14014 Córdoba, Spain
| | - Carmen Tarradas
- Department of Animal Health, UIC Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, International Excellence Agrifood Campus 'CeiA3', University of Córdoba, 14014 Córdoba, Spain
| | - Jaime Gómez-Laguna
- Department of Anatomy and Comparative Pathology and Toxicology, Pathology and Immunology Group (UCO-PIG), UIC Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, International Excellence Agrifood Campus 'CeiA3', 14014 Córdoba, Spain
| | - Belén Huerta
- Department of Animal Health, UIC Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, International Excellence Agrifood Campus 'CeiA3', University of Córdoba, 14014 Córdoba, Spain
| |
Collapse
|
3
|
Sánchez-Carvajal JM, Vera-Salmoral E, Huerta B, Galán-Relaño Á, Ruedas-Torres I, Larenas-Muñoz F, Luque I, Carrasco L, Gómez-Laguna J. Droplet digital PCR as alternative to microbiological culture for Mycobacterium tuberculosis complex detection in bovine lymph node tissue samples. Front Cell Infect Microbiol 2024; 14:1349999. [PMID: 38469351 PMCID: PMC10925636 DOI: 10.3389/fcimb.2024.1349999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 02/07/2024] [Indexed: 03/13/2024] Open
Abstract
Introduction Bovine tuberculosis (bTB) caused by Mycobacterium tuberculosis complex (MTC) remains a significant concern for public health. Direct real-time PCR and droplet digital PCR (ddPCR) are proposed as alternative tools to enhance diagnostic precision and efficiency. This study aims to assess the diagnostic performance of a ddPCR assay targeting IS6110 for the detection of MTC DNA in both microbiological culture and fresh lymph node (LN) tissue samples obtained from cattle, in comparison with the established reference standard, the microbiological culture followed by real-time PCR. Methods The fresh LNs (N=100) were collected each from a different cattle carcass at the slaughterhouse. The limit of detection of ddPCR-IS6110 was set to 101 copies per 20 μl reaction. Results DdPCR-IS6110 detected 44 out of 49 reference-standard positive samples and yielded negative results in 47 out of 51 reference-standard negative samples, resulting in adjusted sensitivity (Se) and specificity (Sp) of 90.76% [95% confidence interval (CI): 82.58 - 98.96%)], and 100% (95% CI: 100%) respectively. The estimated adjusted false negative rate (FNR) was 9.23% (95% CI: 1.04 - 17.42%) and the false positive rate (FPR) was 0% (95% CI: 0%). When directly applied from fresh bovine LN tissues, ddPCR-IS6110 identified 47 out of 49 reference-standard positive samples as ddPCR-IS6110-positive and 42 out of 51 reference-standard negative samples as ddPCR-IS6110-negative, resulting in adjusted Se and Sp values of 94.80% [95% (CI): 88.52 - 100%] and 100% (95% CI: 100%), respectively. The adjusted FNR was 5.20% (95% CI: 0 - 11.50%) and the FPR was 0% (95% CI: 0%). Noteworthy, ddPCR-IS6110 disclosed as positive 9 samples negative to reference-standard. Discussion DdPCR-IS6110 proved to be a rapid, highly sensitive, and specific diagnostic tool as an alternative to reference-standard method.
Collapse
Affiliation(s)
- José María Sánchez-Carvajal
- Department of Anatomy and Comparative Pathology and Toxicology, Pathology and Immunology Group (UCO-PIG), Unidad de Investigación Competitiva (UIC) Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, Córdoba, Spain
| | - Eduardo Vera-Salmoral
- Department of Anatomy and Comparative Pathology and Toxicology, Pathology and Immunology Group (UCO-PIG), Unidad de Investigación Competitiva (UIC) Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, Córdoba, Spain
- Department of Animal Health, Unidad de Investigación Competitiva (UIC) Zoonosis y Enfermedades Emergentes (ENZOEM), University of Córdoba, University of Córdoba, Córdoba, Spain
| | - Belén Huerta
- Department of Animal Health, Unidad de Investigación Competitiva (UIC) Zoonosis y Enfermedades Emergentes (ENZOEM), University of Córdoba, University of Córdoba, Córdoba, Spain
| | - Ángela Galán-Relaño
- Department of Animal Health, Unidad de Investigación Competitiva (UIC) Zoonosis y Enfermedades Emergentes (ENZOEM), University of Córdoba, University of Córdoba, Córdoba, Spain
| | - Inés Ruedas-Torres
- Department of Anatomy and Comparative Pathology and Toxicology, Pathology and Immunology Group (UCO-PIG), Unidad de Investigación Competitiva (UIC) Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, Córdoba, Spain
- UK Health Security Agency (UKHSA), Salisbury, United Kingdom
| | - Fernanda Larenas-Muñoz
- Department of Anatomy and Comparative Pathology and Toxicology, Pathology and Immunology Group (UCO-PIG), Unidad de Investigación Competitiva (UIC) Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, Córdoba, Spain
| | - Inmaculada Luque
- Department of Animal Health, Unidad de Investigación Competitiva (UIC) Zoonosis y Enfermedades Emergentes (ENZOEM), University of Córdoba, University of Córdoba, Córdoba, Spain
| | - Librado Carrasco
- Department of Anatomy and Comparative Pathology and Toxicology, Pathology and Immunology Group (UCO-PIG), Unidad de Investigación Competitiva (UIC) Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, Córdoba, Spain
| | - Jaime Gómez-Laguna
- Department of Anatomy and Comparative Pathology and Toxicology, Pathology and Immunology Group (UCO-PIG), Unidad de Investigación Competitiva (UIC) Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, Córdoba, Spain
| |
Collapse
|
4
|
Juste RA, Fernández-Veiga L, Fuertes M, Fernández-Ortiz de Murua I, Cardona G, Geijo MV, Garrido JM, Sevilla IA. A humoral diagnostic test outperforms cellular tests in a farm with a latent tuberculosis outbreak caused by a new Mycobacterium tuberculosis complex spoligotype that affected sheep but not goats. Front Vet Sci 2024; 10:1310205. [PMID: 38317788 PMCID: PMC10839146 DOI: 10.3389/fvets.2023.1310205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 12/26/2023] [Indexed: 02/07/2024] Open
Abstract
Tuberculosis (TB) is a disease caused by members of the M. tuberculosis complex (MTC) that affects numerous species. M. caprae, a member of the complex which is close to M. bovis, is emerging and affects several different hosts that include goats, cattle, sheep, pigs, rabbits, wild boar, red deer, foxes and also humans. A new M. caprae spoligotype (SB2737) was isolated from an outbreak of sheep tuberculosis affecting a mixed sheep (323)-goat (29) farm in 2021. The index case was detected by the La Rioja slaughterhouse veterinary inspection. Tracing back to the farm of origin, both species were submitted to Comparative Intradermal Tuberculin Test (CITT) and M. bovis-specific antibody ELISA tests. A subsample was also examined by IFN-γ release assay (IGRA) and all positives were slaughtered and pathologically and microbiologically investigated. Only 1.2% of sheep and no goat were positive in the CITT, and 11.4% in the IGRA sheep subsample, while up to 36.8% were positive in two consecutive M. bovis-specific antibody ELISA tests. Goats had always tested negative in annual intradermal follow-up since 2013. Upon confirmation of the immunologically positive sheep at slaughter, all the remaining negative animals were killed and 29.2% of sheep were still found infected. This raised the final overall prevalence to 37.5%. Antibody ELISA was the most sensitive (81.4%) in vivo detection method still showing a 85.0% specificity relative to pathological and microbiological tuberculosis status. It was nearly 10 times more sensitive than skin test and had an 86.8% positive predictive value. Notwithstanding a possible singular pathogenesis of the new spoligotype, this outbreak adds up to previous reports suggesting that sheep tuberculosis could be huge reservoir of infection worldwide overlooked by skin test low sensitivity or simply lack of investigation. This makes it urgent to extend the use antibody tests to address the Trojan horse of hidden M. tuberculosis complex infections on bovine TB control programs.
Collapse
Affiliation(s)
- Ramon A. Juste
- Animal Health Department, NEIKER – Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Derio, Spain
| | - Leire Fernández-Veiga
- Animal Health Department, NEIKER – Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Derio, Spain
| | - Miguel Fuertes
- Animal Health Department, NEIKER – Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Derio, Spain
| | | | - Guillermo Cardona
- Servicio de Ganadería, Diputacion Foral de Alava, Vitoria-Gasteiz, Spain
| | - Maria V. Geijo
- Animal Health Department, NEIKER – Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Derio, Spain
| | - Joseba M. Garrido
- Animal Health Department, NEIKER – Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Derio, Spain
| | - Iker A. Sevilla
- Animal Health Department, NEIKER – Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Derio, Spain
| |
Collapse
|
5
|
Gortázar C, de la Fuente J, Perelló A, Domínguez L. Will we ever eradicate animal tuberculosis? Ir Vet J 2023; 76:24. [PMID: 37737206 PMCID: PMC10515422 DOI: 10.1186/s13620-023-00254-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 09/13/2023] [Indexed: 09/23/2023] Open
Abstract
Two characteristics of the Mycobacterium tuberculosis complex (MTC) are particularly relevant for tuberculosis (TB) epidemiology and control, namely the ability of this group of pathogens to survive in the environment and thereby facilitate indirect transmission via water or feed, and the capacity to infect multiple host species including human beings, cattle, wildlife, and domestic animals other than cattle. As a consequence, rather than keeping the focus on certain animal species regarded as maintenance hosts, we postulate that it is time to think of complex and dynamic multi-host MTC maintenance communities where several wild and domestic species and the environment contribute to pathogen maintenance. Regarding the global situation of animal TB, many industrialized countries have reached the Officially Tuberculosis Free status. However, infection of cattle with M. bovis still occurs in most countries around the world. In low- and middle-income countries, human and animal TB infection is endemic and bovine TB control programs are often not implemented because standard TB control through testing and culling, movement control and slaughterhouse inspection is too expensive or ethically unacceptable. In facing increasingly complex epidemiological scenarios, modern integrated disease control should rely on three main pillars: (1) a close involvement of farmers including collaborative decision making, (2) expanding the surveillance and control targets to all three host categories, the environment, and their interactions, and (3) setting up new control schemes or upgrading established ones switching from single tool test and cull approaches to integrated ones including farm biosafety and vaccination.
Collapse
Affiliation(s)
- Christian Gortázar
- SaBio Instituto de Investigación en Recursos Cinegéticos IREC (UCLM & CSIC), Ciudad Real, Spain
| | - José de la Fuente
- SaBio Instituto de Investigación en Recursos Cinegéticos IREC (UCLM & CSIC), Ciudad Real, Spain
- Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK USA
| | - Alberto Perelló
- SaBio Instituto de Investigación en Recursos Cinegéticos IREC (UCLM & CSIC), Ciudad Real, Spain
- Sabiotec, Camino de Moledores s/n. 13003, Ciudad Real, 13071 Spain
| | - Lucas Domínguez
- VISAVET and Department of Animal Health-Faculty of Veterinary Medicine, Universidad Complutense Madrid, Madrid, Spain
| |
Collapse
|
6
|
Vera-Salmoral E, Gómez-Laguna J, Galán-Relaño Á, Ruedas-Torres I, Carrasco L, Luque I, Huerta B, Sánchez-Carvajal JM. Optimization of real-time PCR protocols from lymph node bovine tissue for direct detection of Mycobacterium tuberculosis complex. Microbiol Spectr 2023; 11:e0034823. [PMID: 37707455 PMCID: PMC10581224 DOI: 10.1128/spectrum.00348-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 07/22/2023] [Indexed: 09/15/2023] Open
Abstract
Bovine tuberculosis (bTB) is a zoonotic disease and a global health problem that is subjected to obligatory eradication programs in the European Union. Microbiological culture is an imperfect technique for bTB diagnosis. This study aims to compare and validate two DNA isolation protocols and three different specific DNA targets, IS6110, IS4, and mpb70, to confirm Mycobacterium tuberculosis complex (MTC) infection by real-time PCR directly from fresh tissue samples. Fresh lymph node samples were collected from 81 cattle carcasses at the slaughterhouse. A comparison of both extraction protocols was performed with IS6110-real-time PCR, showing an adjusted sensitivity (SE) of 78.34% and 95.9% for protocols 1 and 2, respectively, while the specificity (SP) was 100% in both cases. Afterward, the comparison between IS4 and mpb70 targets was performed from the samples extracted with protocol 2, obtaining an adjusted SE of 90.87% and 83.3%, respectively, and an SP of 100% in both cases. The positive likelihood ratio was ∞ for the three targets, and the negative likelihood ratio was 0.04, 0.091, and 0.16 for IS6110, IS4, and mpb70, respectively. Negative predictive values were ≥90%, ≥85%, and ≥80% for real-time PCR targeting IS6110, IS4, and mpb70, respectively, when the true prevalence is ≤60%, and the positive predictive value is 100% in any scenario of true prevalence. According to these results, the DNA extraction protocol 2 and real-time PCR targeting IS6110 or IS4 could be potential first-choice molecular assays to detect MTC directly in fresh bovine tissue samples. IMPORTANCE Bovine tuberculosis (bTB), a chronic infectious and zoonotic disease caused by Mycobacterium tuberculosis complex (MTC), is considered a neglected disease of global importance, causing a detrimental impact on public health, particularly in developing countries where tuberculosis remains a major health problem. However, debate around the efficacy of control measures is still an ongoing matter of concern, with poor diagnostic performance being considered one of the most relevant factors involved in the failure to eradicate the disease since many truly infected animals will be misclassified as bTB-free. This study highlights a DNA extraction protocol and real-time PCR targeting IS6110 or IS4 as potential first-choice molecular assays to detect MTC directly in fresh bovine tissue samples, providing rapid, highly sensitive, and specific diagnostic tools as an alternative to microbiology, which could take up to 3 months to complete, shortening the turnaround time for decision makers to be promptly informed.
Collapse
Affiliation(s)
- Eduardo Vera-Salmoral
- Department of Anatomy and Comparative Pathology and Toxicology, Pathology and Immunology Group (UCO-PIG), UIC Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, International Excellence Agrifood Campus ‘CeiA3’, Córdoba, Spain
- Department of Animal Health, UIC Zoonosis y Enfermedades Emergentes ENZOEM, International Excellence Agrifood Campus ‘CeiA3’, University of Córdoba, Córdoba, Spain
| | - Jaime Gómez-Laguna
- Department of Anatomy and Comparative Pathology and Toxicology, Pathology and Immunology Group (UCO-PIG), UIC Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, International Excellence Agrifood Campus ‘CeiA3’, Córdoba, Spain
| | - Ángela Galán-Relaño
- Department of Animal Health, UIC Zoonosis y Enfermedades Emergentes ENZOEM, International Excellence Agrifood Campus ‘CeiA3’, University of Córdoba, Córdoba, Spain
| | - Inés Ruedas-Torres
- Department of Anatomy and Comparative Pathology and Toxicology, Pathology and Immunology Group (UCO-PIG), UIC Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, International Excellence Agrifood Campus ‘CeiA3’, Córdoba, Spain
| | - Librado Carrasco
- Department of Anatomy and Comparative Pathology and Toxicology, Pathology and Immunology Group (UCO-PIG), UIC Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, International Excellence Agrifood Campus ‘CeiA3’, Córdoba, Spain
| | - Inmaculada Luque
- Department of Animal Health, UIC Zoonosis y Enfermedades Emergentes ENZOEM, International Excellence Agrifood Campus ‘CeiA3’, University of Córdoba, Córdoba, Spain
| | - Belén Huerta
- Department of Animal Health, UIC Zoonosis y Enfermedades Emergentes ENZOEM, International Excellence Agrifood Campus ‘CeiA3’, University of Córdoba, Córdoba, Spain
| | - José María Sánchez-Carvajal
- Department of Anatomy and Comparative Pathology and Toxicology, Pathology and Immunology Group (UCO-PIG), UIC Zoonosis y Enfermedades Emergentes ENZOEM, University of Córdoba, International Excellence Agrifood Campus ‘CeiA3’, Córdoba, Spain
- Institute of Virology and Immunology IVI, Sensemattstrasse, Mittelhäusern, Switzerland
| |
Collapse
|
7
|
Bezos J, Sáez-Llorente JL, Álvarez J, Romero B, Díez-Guerrier A, Domínguez L, de Juan L. Bovine tuberculosis in Spain, is it really the final countdown? Ir Vet J 2023; 76:13. [PMID: 37491275 PMCID: PMC10369685 DOI: 10.1186/s13620-023-00241-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 07/10/2023] [Indexed: 07/27/2023] Open
Abstract
Bovine tuberculosis (bTB) is a severe zoonotic disease that has major impacts on both health and the economy, and which has been subjected to specific eradication programmes in many countries for decades. This manuscript highlights the relevance of this disease in the context of the European Union (EU) and summarizes the epidemiological situation and the main tools (e.g. antemortem diagnostic tests, slaughterhouse surveillance, laboratories, comprehensive databases, etc.) used to control and eradicate bTB in the various EU countries with a focus on the situation in Spain. A comprehensive description of the specific bTB epidemiological situation in Spain is provided, together with an assessment of the evolution of different epidemiological indicators throughout the last decades. Moreover, the main features of the Spanish bTB eradication programme and its control tools are described, along with the studies carried out in Spain that have allowed the updating of and improvement to the programme over the years with the aim of eradication, which has been established for 2030.
Collapse
Affiliation(s)
- Javier Bezos
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain
- VISAVET Health Surveillance Centre, Complutense University of Madrid, Madrid, Spain
| | | | - Julio Álvarez
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain
- VISAVET Health Surveillance Centre, Complutense University of Madrid, Madrid, Spain
| | - Beatriz Romero
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain
- VISAVET Health Surveillance Centre, Complutense University of Madrid, Madrid, Spain
| | - Alberto Díez-Guerrier
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain
- VISAVET Health Surveillance Centre, Complutense University of Madrid, Madrid, Spain
| | - Lucas Domínguez
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain
- VISAVET Health Surveillance Centre, Complutense University of Madrid, Madrid, Spain
| | - Lucía de Juan
- Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid, Spain
- VISAVET Health Surveillance Centre, Complutense University of Madrid, Madrid, Spain
| |
Collapse
|
8
|
Pozo P, Bezos J, Romero B, Grau A, Nacar J, Saez JL, Minguez O, Alvarez J. Once bitten twice shy: Risk factors associated with bovine tuberculosis recurrence in Castilla y Leon, Spain. Res Vet Sci 2023; 159:72-80. [PMID: 37087923 DOI: 10.1016/j.rvsc.2023.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 04/04/2023] [Accepted: 04/15/2023] [Indexed: 04/25/2023]
Abstract
Persistence of bovine tuberculosis (bTB) in cattle herd remains a major challenge in disease elimination due to the ineffectual removal of all infected animals in a bTB breakdown. Characterization of herds with a higher probability of experiencing further bTB breakdowns can help to implement specific risk-based policies for disease control and eradication. Here, our aim was to identify herd- and breakdown-level risk factors in bTB infected herds in Castilla y Leon, Spain, associated with a decreased time to recurrence and an increased risk of recurrence using a mixed effects Cox proportional hazards model and a multivariable logistic regression model, respectively. Results revealed that location (province), herd size and number of incoming animals/contacts were good predictors of a decreased time to bTB recurrence and an increased risk of becoming a recurrent herd. Additionally, the duration of the previous outbreak and the number of IFN-γ herd-tests applied in it were associated with increased odds of (an early) recurrence. Risk factors identified here can be used for early identification of herds in which bTB eradication may be more challenging and that should thus be subjected to increased control efforts. The characterization of high-risk herds may help to minimize the risk of reinfection and emphasize early detection and removal of bTB positive animals in the herd.
Collapse
Affiliation(s)
- Pilar Pozo
- VISAVET Health Surveillance Centre, Universidad Complutense de Madrid, Madrid, Spain; SaBio, Instituto de Investigación en Recursos Cinegéticos IREC-CSIC-UCLM-JCCM, Ciudad Real, Spain.
| | - Javier Bezos
- VISAVET Health Surveillance Centre, Universidad Complutense de Madrid, Madrid, Spain; Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid. Spain
| | - Beatriz Romero
- VISAVET Health Surveillance Centre, Universidad Complutense de Madrid, Madrid, Spain; Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid. Spain
| | - Anna Grau
- Dirección General de Producción Agropecuaria e Infraestructuras Agrarias, Consejería de Agricultura y Ganadería de la Junta de Castilla y León, Valladolid, Spain
| | - Jesus Nacar
- Dirección General de Producción Agropecuaria e Infraestructuras Agrarias, Consejería de Agricultura y Ganadería de la Junta de Castilla y León, Valladolid, Spain
| | - Jose Luis Saez
- Subdirección General de Sanidad e Higiene Animal y Trazabilidad, Dirección General de Sanidad de la Producción Agraria, Ministerio de Agricultura, Pesca y Alimentación, Madrid, Spain
| | - Olga Minguez
- Consejería de Sanidad de la Junta de Castilla y León, Valladolid, Spain
| | - Julio Alvarez
- VISAVET Health Surveillance Centre, Universidad Complutense de Madrid, Madrid, Spain; Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de Madrid, Madrid. Spain
| |
Collapse
|
9
|
Accuracy of Tests for Diagnosis of Animal Tuberculosis: Moving Away from the Golden Calf (and towards Bayesian Models). Transbound Emerg Dis 2023. [DOI: 10.1155/2023/7615716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
The last decades have seen major efforts to develop new and improved tools to maximize our ability to detect tuberculosis-infected animals and advance towards the objective of disease control and ultimately eradication. Nevertheless, there is still uncertainty regarding test performance due to the wide range of specificity and especially sensitivity estimates published in the scientific literature. Here, we performed a systematic review of the literature on studies that evaluated the performance of tuberculosis diagnostic tests used in animals through Bayesian Latent Class Models (BLCMs), which do not require the application of a (fallible) reference procedure to classify animals as infected with tuberculosis or not. BLCM-based sensitivity and specificity estimates deviated from those obtained using a reference procedure for certain antemortem tests: an overall lower sensitivity of skin tests and serology and a higher sensitivity of interferon-gamma (IFN-γ) assays was reported. In the case of postmortem diagnostic tests, sensitivity estimates from BLCMs were similar to estimates from studies based on other methodologies. For specificity, the range of BLCM-based estimates was narrower than those based on a reference test, reaching values close to 100% (but lower in the case of IFN-γ assays). In conclusion, Bayesian methods have been increasingly applied for the evaluation of tuberculosis diagnostic tests in animals, yielding results that differ (sometimes substantially) from previously reported test performance in the literature, particularly for in vivo tests and sensitivity estimates. Newly developed models that allow adjustment for relevant factors (e.g., age, breed, region, and herd size) can contribute to the generation of more unbiased estimates of test performance. Nevertheless, although BLCMs for tuberculosis do not require the use of an imperfect reference procedure and are therefore not influenced by its limited performance, they require careful implementation, and transparent systematic reporting should be the norm.
Collapse
|