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Rasmussen P, Shaw APM, Muñoz V, Bruce M, Torgerson PR. Estimating the burden of multiple endemic diseases and health conditions using Bayes’ Theorem: A conditional probability model applied to UK dairy cattle. Prev Vet Med 2022; 203:105617. [PMID: 35358837 PMCID: PMC9127345 DOI: 10.1016/j.prevetmed.2022.105617] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/14/2022] [Accepted: 03/16/2022] [Indexed: 11/18/2022]
Abstract
The Global Burden of Animal Diseases (GBADs) is an international collaboration aiming, in part, to measure and improve societal outcomes from livestock. One GBADs objective is to estimate the economic impact of endemic diseases in livestock. However, if individual disease impact estimates are linearly aggregated without consideration for associations among diseases, there is the potential to double count impacts, overestimating the total burden. Accordingly, the authors propose a method to adjust an array of individual disease impact estimates so that they may be aggregated without overlap. Using Bayes’ Theorem, conditional probabilities were derived from inter-disease odds ratios in the literature. These conditional probabilities were used to calculate the excess probability of disease among animals with associated conditions, or the probability of disease overlap given the odds of coinfection, which were then used to adjust disease impact estimates so that they may be aggregated. The aggregate impacts, or the yield, fertility, and mortality gaps due to disease, were then attributed and valued, generating disease-specific losses. The approach was illustrated using an example dairy cattle system with input values and supporting parameters from the UK, with 13 diseases and health conditions endemic to UK dairy cattle: cystic ovary, disease caused by gastrointestinal nematodes, displaced abomasum, dystocia, fasciolosis, lameness, mastitis, metritis, milk fever, neosporosis, paratuberculosis, retained placenta, and subclinical ketosis. The diseases and conditions modelled resulted in total adjusted losses of £ 404/cow/year, equivalent to herd-level losses of £ 60,000/year. Unadjusted aggregation methods suggested losses 14–61% greater. Although lameness was identified as the costliest condition (28% of total losses), variations in the prevalence of fasciolosis, neosporosis, and paratuberculosis (only a combined 22% of total losses) were nearly as impactful individually as variations in the prevalence of lameness. The results suggest that from a disease control policy perspective, the costliness of a disease may not always be the best indicator of the investment its control warrants; the costliness rankings varied across approaches and total losses were found to be surprisingly sensitive to variations in the prevalence of relatively uncostly diseases. This approach allows for disease impact estimates to be aggregated without double counting. It can be applied to any livestock system in any region with any set of endemic diseases, and can be updated as new prevalence, impact, and disease association data become available. This approach also provides researchers and policymakers an alternative tool to rank prevention priorities. Three approaches to impact aggregation for multiple endemic diseases explored. Flexible method proposed to avoid double counting impacts within a livestock system. Illustrated using 13 endemic diseases and health conditions in UK dairy cattle. Provides an alternative perspective on ranking disease prevention priorities.
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Affiliation(s)
| | - Alexandra P M Shaw
- Department of Livestock and One Health, University of Liverpool, Liverpool, United Kingdom
| | - Violeta Muñoz
- Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Mieghan Bruce
- School of Veterinary Medicine, Centre for Biosecurity and One and Health, Murdoch University, Murdoch, Australia
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Rodrigues DL, Amorim EA, Ferreira F, Amaku M, Baquero OS, de Hildebrand e Grisi Filho JH, Dias RA, Heinemann MB, Telles EO, Gonçalves VSP, Compton C, Ferreira Neto JS. Apparent prevalence and risk factors for bovine tuberculosis in the state of Paraná, Brazil: an assessment after 18 years since the beginning of the Brazilian program. Trop Anim Health Prod 2022; 54:360. [PMID: 36279048 PMCID: PMC9592671 DOI: 10.1007/s11250-022-03350-0] [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: 05/16/2022] [Accepted: 10/12/2022] [Indexed: 12/14/2022]
Abstract
Bovine tuberculosis (bTB) impacts considerably animal production and one health worldwide. To describe the prevalence, risk factors, and spatial pattern of the disease in the state of Paraná, Brazil, a cross-sectional study was conducted from September 2018 to February 2019. The area was divided into seven regions. Within each region, farms were randomly selected, and a predetermined number of cows was selected and tested by a comparative cervical tuberculin test. 17,210 animals were tested across 1757 farms. Herd prevalence of bTB-infected herds in Paraná was 2.5% [1.87-3.00%]. It has varied from 0.8 to 3.98% among seven regions, with clustering being detected in the west, central, and northeast areas. Animal prevalence was 0.35% [0.21-0.59%] and has varied from 0.08 to 0.6% among the pre-set regions. No major shifts in the prevalence of bTB were detected since 2007. Large-sized herds, dairy production, and feeding with whey were detected to be correlated with the presence of bTB. Exclusively among dairy herds, veterinary assistance from cooperatives, possession of self-owned equipment to cool milk, and feeding with whey were correlated with the disease. Considering these results, it is recommended that the state of Paraná seek to implement a surveillance system for the detection of bTB-infected herds transforming them into free ones, if possible, incorporating elements of risk-based surveillance. Health education is also recommended to inform farmers about the risks of introducing animals without testing and of feeding raw whey to calves.
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Affiliation(s)
- Diego Leonardo Rodrigues
- Ministry of Agriculture, Livestock and Supply of Brazil (MAPA), 420, José Veríssimo Street, Tarumã, Curitiba, Paraná Brazil
| | - Elenice Aparecida Amorim
- Paraná Agribusiness Defense Agency (ADAPAR), 1559, Funcionários Street, Cabral, Curitiba, Paraná Brazil
| | - Fernando Ferreira
- Department of Preventive Veterinary Medicine, University of São Paulo, 87, Prof. Orlando Marques de Paiva Avenue, São Paulo, Brazil
| | - Marcos Amaku
- Department of Preventive Veterinary Medicine, University of São Paulo, 87, Prof. Orlando Marques de Paiva Avenue, São Paulo, Brazil
| | - Oswaldo Santos Baquero
- Department of Preventive Veterinary Medicine, University of São Paulo, 87, Prof. Orlando Marques de Paiva Avenue, São Paulo, Brazil
| | | | - Ricardo Augusto Dias
- Department of Preventive Veterinary Medicine, University of São Paulo, 87, Prof. Orlando Marques de Paiva Avenue, São Paulo, Brazil
| | - Marcos Bryan Heinemann
- Department of Preventive Veterinary Medicine, University of São Paulo, 87, Prof. Orlando Marques de Paiva Avenue, São Paulo, Brazil
| | - Evelise Oliveira Telles
- Department of Preventive Veterinary Medicine, University of São Paulo, 87, Prof. Orlando Marques de Paiva Avenue, São Paulo, Brazil
| | - Vitor Salvador Picão Gonçalves
- EpiPlan, Faculty of Agronomy and Veterinary Medicine, University of Brasília, Ala Central Do Instituto Central de Ciências, Brasília, Distrito Federal Brazil
| | - Christopher Compton
- The Epicentre, Massey University, Wool Building, University Avenue, Massey University Manawatu (Turitea), 4474 Palmerston North, New Zealand
| | - José Soares Ferreira Neto
- Department of Preventive Veterinary Medicine, University of São Paulo, 87, Prof. Orlando Marques de Paiva Avenue, São Paulo, Brazil
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Mellado M, Treviño N, Véliz FG, Macías-Cruz U, Avendaño-Reyes L, de Santiago A, García JE. Effect of co-positivity for brucellosis and tuberculosis on milk yield and fertility of Holstein cows. Trop Anim Health Prod 2021; 53:504. [PMID: 34622357 DOI: 10.1007/s11250-021-02952-4] [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: 06/26/2020] [Accepted: 09/30/2021] [Indexed: 11/29/2022]
Abstract
This study aimed to determine whether cows detected as tuberculosis (bTB) reactors and seropositive to brucellosis (bBR), as well as co-positive to bBR and bTB (bBR-bTB) and with a complete lactation before slaughter, were associated with reduced milk production and fertility. A total of 8068 productive and reproductive records of high-yielding Holstein cows from a single large dairy herd with a high prevalence of bTB and bBR were collected from 2012 to 2015. Lactation derived either from calving (n = 6019) or hormonally induced lactation (n = 2049), and all cows received growth hormone throughout lactation. For cows not induced into lactation, pregnancy rate to first service for healthy cows (C; 26.6%) was higher (P < 0.01) than bBR (15.2%), bTB (15.8%), and bBR-bTB (1.3%) cows. For induced cows, pregnancy rate to first service did not differ significantly among C, bBR, and bTB (14.5-17.3%) cows, but the percentage success of first service was extremely low (1.3%; P < 0.01) in bBR-bTB cows. Services per pregnancy (only pregnant cows) were lowest for C (3.3 ± 2.9; P < 0.01) and highest (6.4 ± 3.4) for bBR-bTB non-induced cows. This variable was lowest for C (2.9 ± 2.5; P < 0.01) and highest for bBR-bTB non-induced cows (6.3 ± 3.1). Pregnancy rate to all services did not differed for C (79.5%), bBR (76.7%), and bTB (75.9%) but was lower (58.9%; P < 0.01) for bBR-bTB non-induced cows. For induced cows this variable was highest for bBR (53.3%) and lowest for bBR-bTB (34.1%; P < 0.01) non-induced cows. 305-d milk production was increased by 4%, and total milk yield by 7% in TB-positive cows compared to that of the negative cows non-induced hormonally into lactation. This study showed the negative impact of the co-positivity for bTB and bBR on the reproductive efficiency of Holstein cows, although positive bTB and bBR tests enhanced milk yield.
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Affiliation(s)
- M Mellado
- Department of Animal Nutrition, Autonomous Agrarian University Antonio Narro, 25315, Saltillo, Coahuila, Mexico
| | - N Treviño
- Department of Animal Nutrition, Autonomous Agrarian University Antonio Narro, 25315, Saltillo, Coahuila, Mexico
| | - F G Véliz
- Department of Veterinary Science, Autonomous Agrarian University Antonio Narro, 27054, Torreon, Mexico
| | - U Macías-Cruz
- Institute of Agriculture Science, Autonomous University of Baja California, 21705, Mexicali, Mexico
| | - L Avendaño-Reyes
- Institute of Agriculture Science, Autonomous University of Baja California, 21705, Mexicali, Mexico
| | - A de Santiago
- Department of Veterinary Science, Autonomous Agrarian University Antonio Narro, 27054, Torreon, Mexico
| | - J E García
- Department of Animal Nutrition, Autonomous Agrarian University Antonio Narro, 25315, Saltillo, Coahuila, Mexico.
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Tschopp R, Conlan AJK, Gemechu G, Almaw G, Hattendorf J, Zinsstag J, Wood JLN. Effect of Bovine Tuberculosis on Selected Productivity Parameters and Trading in Dairy Cattle Kept Under Intensive Husbandry in Central Ethiopia. Front Vet Sci 2021; 8:698768. [PMID: 34368283 PMCID: PMC8334357 DOI: 10.3389/fvets.2021.698768] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 06/18/2021] [Indexed: 11/13/2022] Open
Abstract
Bovine tuberculosis (BTB) has substantial impact on fertility, milk, and meat productivity in cattle. However, these assumptions are based on outdated data. Recent global studies on the impact of BTB on cattle productivity are scarce and show sometimes inconclusive and/or contradicting results. This pilot study is the first longitudinal study performed in urban upgraded dairy cattle in Ethiopia that are kept under intensive husbandry. We assessed whether BTB has an impact on various animal productivity parameters and animal movement. Animals (N = 890) included in the study were tested for BTB at least once using the comparative intradermal tuberculin test (CIDT). Fertility, mortality, and offtake were assessed in 21 dairy farms where herd follow-ups over 3 years were performed. In addition, an independent abattoir survey was conducted to assess carcass weight and visible TB-like lesions upon meat inspection. Animal movements (purchasing and offtakes) were documented for each farm. The impact of BTB status on the intervals been birth, service, and calving times and the intercalving intervals was analyzed using a Cox proportional hazards model. The hazard ratio associated with BTB-positive animals was smaller than 1 for all fertility parameters, suggesting that BTB status increases the time between events; however, the effect was small and only statistically significant (95% level) for the time between calving and service. Offtakes included a higher percentage of reactor animals (58%) as compared with non-reactor animals (42%) (p = 0.0001). Overall, reactors were eliminated from the farms within 238.6 days after receiving test results, which was 54.9 days faster than for negative animals. The majority of owners purchased animals within their town or its surrounding. Nearly a quarter of reactors were sold directly to other farms. Animals were also sold further away, including other regions, raising the question of disease spread and the need for an animal tracing mechanism. In the abattoir survey, a total of 349 carcasses were weighed, of which 8% showed visible TB-like lesions and 53.6% had fasciolosis. Negative adult bull carcasses were 7.5 kg heavier than reactor bulls.
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Affiliation(s)
- Rea Tschopp
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- One-Health Unit, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Andrew J. K. Conlan
- University of Basel, Basel, Switzerland
- Disease Dynamics Unit, Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Gizachew Gemechu
- One-Health Unit, Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Gizat Almaw
- National Animal Health Diagnostic and Investigation Center, Sebeta, Ethiopia
| | - Jan Hattendorf
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jakob Zinsstag
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | - James L. N. Wood
- Disease Dynamics Unit, Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
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Tazerart F, Saad J, Sahraoui N, Yala D, Niar A, Drancourt M. Whole Genome Sequence Analysis of Mycobacterium bovis Cattle Isolates, Algeria. Pathogens 2021; 10:pathogens10070802. [PMID: 34202816 PMCID: PMC8308521 DOI: 10.3390/pathogens10070802] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/11/2021] [Accepted: 06/18/2021] [Indexed: 11/16/2022] Open
Abstract
Mycobacterium bovis (M. bovis), a Mycobacterium tuberculosis complex species responsible for tuberculosis in cattle and zoonotic tuberculosis in humans, is present in Algeria. In Algeria however, the M. bovis population structure is unknown, limiting understanding of the sources and transmission of bovine tuberculosis. In this study, we identified the whole genome sequence (WGS) of 13 M. bovis strains isolated from animals exhibiting lesions compatible with tuberculosis, which were slaughtered and inspected in five slaughterhouses in Algeria. We found that six isolates were grouped together with reference clinical strains of M. bovis genotype-Unknown2. One isolate was related to M. bovis genotype-Unknown7, one isolate was related to M. bovis genotype-Unknown4, three isolates belonged to M. bovis genotype-Europe 2 and there was one new clone for two M. bovis isolates. Two isolates from Blida exhibited no pairwise differences in single nucleotide polymorphisms. None of these 13 isolates were closely related to four zoonotic M. bovis isolates previously characterized in Algeria. In Algeria, the epidemiology of bovine tuberculosis in cattle is partly driven by cross border movements of animals and animal products.
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Affiliation(s)
- Fatah Tazerart
- Laboratoire d’Agro Biotechnologie et de Nutrition des Zones Semi Arides, Université Ibn Khaldoun, Tiaret 14000, Algeria;
- Institut des Sciences Vétérinaires, Université de Blida 1, Blida 09000, Algeria;
- Institut Hospitalo-Universitaire Méditerranée Infection, 13005 Marseille, France;
| | - Jamal Saad
- Institut Hospitalo-Universitaire Méditerranée Infection, 13005 Marseille, France;
- Faculté de Médecine, Aix-Marseille-Université, IHU Méditerranée Infection, 13005 Marseille, France
| | - Naima Sahraoui
- Institut des Sciences Vétérinaires, Université de Blida 1, Blida 09000, Algeria;
| | - Djamel Yala
- Laboratoire National de Référence pour la Tuberculose et Mycobactéries, Institut Pasteur d’Algérie, Alger 16015, Algeria;
| | - Abdellatif Niar
- Laboratoire de Reproduction des Animaux de la Ferme, Université Ibn Khaldoun, Tiaret 14000, Algeria;
| | - Michel Drancourt
- Institut Hospitalo-Universitaire Méditerranée Infection, 13005 Marseille, France;
- Faculté de Médecine, Aix-Marseille-Université, IHU Méditerranée Infection, 13005 Marseille, France
- Correspondence:
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Risk factors associated with testing positive for tuberculosis in high-yielding Holstein cows. Trop Anim Health Prod 2021; 53:149. [PMID: 33532976 DOI: 10.1007/s11250-021-02599-1] [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: 07/14/2020] [Accepted: 01/27/2021] [Indexed: 10/22/2022]
Abstract
Tuberculosis remains a significant infectious disease of farm animals and humans worldwide. The objective of this study was to assess various risk factors associated with testing positive for bovine tuberculosis (bTB) in high-yielding Holstein cows in an intensive dry-lot dairy operation. In a retrospective observational study, 9312 records from Holstein cows from a large dairy herd in northern Mexico were used. The incidence rate of lactating cows reactor to bTB was 7.3 cases/100 cow years (95% CI = 6.7-7.9%). Multiple logistic regression models indicated that cows with total milk yield during the first lactation >10,200 kg were 1.3 times (95% confidence intervals (CI) for odds ratio (OR) = 1.2-1.6) more likely to be detected as bTB reactors than cows with total milk yield <10,200 kg (8.2 vs. 6.4%; P < 0.01). The risk of being reactor to bTB increased with x̅ total milk yield/lactation >11,500 kg (OR=2.7, 95% CI = 2.3-3.3; 10.4 vs. 4.2%) compared with cows with x̅ total milk yield/lactation <11,500 kg. Cows with >10,200 kg 305-day milk yield in the last lactation was associated (P < 0.01) with 1.3 times higher odds (95% CI for OR = 1.1-1.5) of being classed as reactors than cows with <10,200 kg. Cows with peak milk yield >48 kg were 1.9 times (95% CI for OR = 1.6-2.2) more likely to be reactor to bTB than cows with peak milk yield <48 kg (9.2 vs. 5.1%; P < 0.01). Cows with either puerperal metritis (OR = 0.07, 95% CI = 0.5-0.9) or carrying twins (OR = 0.05, 95% CI = 0.01-0.19) had a protective role for being reactor to bTB. This study showed that increased milk production was associated with a higher risk of becoming positive to tuberculin skin test in high-yielding Holstein cows.
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Garbaccio SG, Garro CJ, Delgado F, Tejada GA, Eirin ME, Huertas PS, Leon EA, Zumárraga MJ. Enzyme-linked immunosorbent assay as complement of intradermal skin test for the detection of mycobacterium bovis infection in cattle. Tuberculosis (Edinb) 2019; 117:56-61. [PMID: 31378269 DOI: 10.1016/j.tube.2019.05.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 05/21/2019] [Accepted: 05/26/2019] [Indexed: 10/26/2022]
Abstract
Diagnostic tests based on cell-mediated immunity are used in programs for the control and eradication of bovine tuberculosis (bTB), which is mainly caused by Mycobacterium bovis. Additional serological assays could be performed as an ancillary method to detect an infected animal that fails to produce an immune response against the intradermal reaction (IDR), the official bTB test. In this study, we evaluated the effectiveness of an enzyme-linked immunosorbent assay (ELISA) that uses bovine PPD as a capture antigen as a complement to the IDR in herds with confirmed cases of bTB. The study was conducted in two stages. First, a panel of 200 serum samples was analyzed by ELISA. The sensitivity and specificity obtained were 60% and 99%, respectively. The subsequent stage consisted of evaluating 7,494 bovines from 14 selected dairy farms. The number of animals yielding a IDR negative/ELISA positive result were 200. A necropsy analysis of 33 of these IDR negative/ELISA positive animals revealed that 30 (91%) presented granulomatous lesions and positive M. bovis isolation. This finding confirmed bTB in most cases. Altogether, the results obtained in the present study suggest that the combined use of IDR and ELISA is an effective strategy to improve the control of bTB in endemic herds.
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Affiliation(s)
- S G Garbaccio
- Pathobiology Veterinary Institute, National Institute of Agricultural Technology (INTA), Hurlingham, 1686, Argentina.
| | - C J Garro
- Pathobiology Veterinary Institute, National Institute of Agricultural Technology (INTA), Hurlingham, 1686, Argentina
| | - F Delgado
- Pathobiology Veterinary Institute, National Institute of Agricultural Technology (INTA), Hurlingham, 1686, Argentina
| | - G A Tejada
- Colón Diagnosis Laboratory Services, Morón, 1708, Argentina
| | - M E Eirin
- Biotechnology Institute, National Institute of Agricultural Technology (INTA), Hurlingham, 1686, Argentina
| | - P S Huertas
- Pathobiology Veterinary Institute, National Institute of Agricultural Technology (INTA), Hurlingham, 1686, Argentina
| | - E A Leon
- Pathobiology Veterinary Institute, National Institute of Agricultural Technology (INTA), Hurlingham, 1686, Argentina
| | - M J Zumárraga
- Biotechnology Institute, National Institute of Agricultural Technology (INTA), Hurlingham, 1686, Argentina
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Prevalence and Economic Losses Due to Bovine Tuberculosis in Cattle Slaughtered at Bodija Municipal Abattoir, Ibadan, Nigeria. FOLIA VETERINARIA 2019. [DOI: 10.2478/fv-2019-0006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Bovine tuberculosis (BTB) is a zoonotic disease responsible for considerable economic losses; with consequent negative impact on both public health and the livestock industry. However, the burden of this disease and associated economic losses remain un-investigated among slaughtered cattle in Ibadan, the hub of livestock activities in south-western Nigeria. A cross sectional study was conducted over a three-month period to determine the prevalence and economic losses due to BTB among slaughtered cattle at the Bodija Municipal Abattoir, Ibadan, in south-western Nigeria. Individual slaughtered cattle were purposively inspected for the presence of tuberculous lesions, and representative sample of affected organs and associated lymph nodes from the BTB suspected animals were taken. The suspected lesions were processed based on Becton Dickinson digestion and decontamination procedure and the losses due to BTB were estimated mathematically, using a formula. The BTB prevalence of 9.3 % (38/408) was obtained with a significant statistical association (P ≤ 0.05) of the disease with the breeds of cattle slaughtered. Out of the 46 visceral organs condemned: 29 (63 %) were lungs, 12 (26.1 %) livers, 4 (8.7 %) hearts and 1 (2.2 %) kidney. The total estimated annual economic loss (direct and indirect) due to BTB was estimated as Nigerian naria NGN 703,980,070 (EUR 1,725,441.4). This study revealed BTB as endemic and a major cause of concern considering its ill-health and economic effects on both humans and the livestock industry. Efforts are therefore required: to control this disease along the beef value chain in order to safeguard human and livestock health; as well as to limit the economic losses associated with its prevalence.
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Jajere SM, Atsanda NN, Bitrus AA, Hamisu TM, Goni MD. A retrospective study of bovine tuberculosis at the municipal abattoir of Bauchi State, Northeastern Nigeria. Vet World 2018; 11:598-605. [PMID: 29915497 PMCID: PMC5993755 DOI: 10.14202/vetworld.2018.598-605] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 04/03/2018] [Indexed: 11/17/2022] Open
Abstract
Background and Aim: Bovine tuberculosis (bTB) still remains a major zoonotic bacterial disease affecting livestock and humans worldwide. The disease remains a poorly managed tropical disease in most developing countries of the world; where in addition to productivity losses and significance in international trade, it posed a major public health threat to both humans and animals. A retrospective study was designed to investigate the occurrence of bTB lesions at Bauchi municipal abattoir. Materials and Methods: The study utilized abattoir records spanning a period of 10 years (2004-2013). The records indicated that a total of 1,08,638 heads of cattle comprising n = 56,070 males and n = 52,570 females were slaughtered at the municipal abattoir during the study period. Result: Of these heads, n = 1230 (1.13%) (95% confidence interval [CI]: 1.07, 1.19) had tuberculous lesions. The annual occurrence during the study period varied significantly (p<0.001) from 0.53% (95% CI: 0.40, 0.67) to 1.87% (95% CI: 1.66, 2.10) in 2010 and 2012, respectively. Females had a significantly higher (p<0.001) prevalence of 2.10% (95% CI: 1.98, 2.23) compared with the males 0.23% (95% CI: 0.19, 0.27). The distribution of suspected gross bTB lesions in different organs showed 11.87% in the lungs, 5.93% in the liver, 1.14% in the heart, and 0.49% accounted for generalized bTB. However, none was observed on the lymph nodes and intestines. Conclusion: It can be concluded that bTB persists in Bauchi State with annual variations during the study period. This study highlights the importance of meat inspection as an important tool for detecting the presence of bTB lesions.
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Affiliation(s)
- Saleh Mohammed Jajere
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.,Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Maiduguri, P.M.B. 1069, Maiduguri, Borno, Nigeria
| | - Naphtali Nayamanda Atsanda
- Department of Veterinary Public Health and Preventive Medicine, Faculty of Veterinary Medicine, University of Maiduguri, P.M.B. 1069, Maiduguri, Borno, Nigeria
| | - Asinamai Athliamai Bitrus
- Department of Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.,Research Unit in Microbial Food Safety and Antimicrobial Resistance, Department of Veterinary Public Health, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Tasiu Mallam Hamisu
- Department of Veterinary Microbiology, Faculty of Veterinary Medicine, University of Maiduguri, P.M.B. 1069 Maiduguri, Borno, Nigeria
| | - Mohammed Dauda Goni
- Department of Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
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Factors Affecting Herd Status for Bovine Tuberculosis in Dairy Cattle in Northern Thailand. Vet Med Int 2017; 2017:2964389. [PMID: 28553557 PMCID: PMC5434264 DOI: 10.1155/2017/2964389] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 02/25/2017] [Accepted: 03/22/2017] [Indexed: 11/17/2022] Open
Abstract
The objective of this case-control study was to identify farm-level risk factors associated with bovine tuberculosis (bTB) in dairy cows in northern Thailand. Spatial analysis was performed to identify geographical clustering of case-farms located in Chiang Mai and Chiang Rai provinces in northern Thailand. To identify management factors affecting bTB status, a matched case-control study was conducted with 20 case-farms and 38 control-farms. Case-farms were dairy farms with at least single intradermal tuberculin test- (SIT-) reactor(s) in the farms during 2011 to 2015. Control-farms were dairy farms with no SIT-reactors in the same period and located within 5 km from case-farms. Questionnaires were administered for data collection with questions based on epidemiological plausibility and characteristics of the local livestock industry. Data were analyzed using multiple logistic regressions. A significant geographic cluster was identified only in Chiang Mai province (p < 0.05). The risk factor associated with presence of SIT-reactors in dairy herds located in this region was purchasing dairy cows from dealers (OR = 5.85, 95% CI = 1.66-20.58, and p = 0.006). From this study, it was concluded that geographic clustering was identified for dairy farms with SIT-reactors in these provinces, and the cattle movements through cattle dealers increased the risks for SIT-reactor farm status.
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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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Bhaladhare A, Sharma D, Kumar A, Sonwane A, Chauhan A, Singh R, Kumar P, Yadav R, Baqir M, Bhushan B, Prakash O. Single nucleotide polymorphisms in toll-like receptor genes and case-control association studies with bovine tuberculosis. Vet World 2016; 9:458-64. [PMID: 27284220 PMCID: PMC4893715 DOI: 10.14202/vetworld.2016.458-464] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 03/21/2016] [Indexed: 11/22/2022] Open
Abstract
Aim: Toll-like receptor 2 (TLR2) and TLR4 genes play critical roles in host recognition of Mycobacterium bovis infection and initiation of innate and adaptive immune response. The present study was aimed at exploring the association of seven single nucleotide polymorphisms (SNPs) in TLR2 and TLR4 genes with susceptibility/resistance against bovine tuberculosis (bTB) infection in cattle. Materials and Methods: A case-control resource population of 35 positive and 45 negative animals was developed after screening with single intradermal tuberculin test for bTB. Resource population was screened for SNPs in TLR2 and TLR4 genes using polymerase chain reaction-restriction fragment length polymorphism. The PROC LOGISTIC procedure of SAS 9.3 was used to find an association of allelic and genotypic frequencies with bTB. Results: In TLR2 gene, two of SNPs under study (rs55617172 and rs68268253) revealed polymorphism while in the case of TLR4 gene all four SNPs under investigation (rs8193041, rs207836014, rs8193060, and rs8193069) were found to be polymorphic in case-control population. SNP locus rs55617172 in TLR2 gene was found significantly (p<0.01) associated with susceptibility/resistance to TB in cattle. Conclusion: These findings indicate the presence of SNPs in TLR2 and TLR4 genes in our resource population. Upon validation in independent, large resource population and following biological characterization, SNP rs55617172 can be incorporated in marker panel for selection of animals with greater resistance to bTB.
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Affiliation(s)
- Ashish Bhaladhare
- Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - Deepak Sharma
- Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - Amit Kumar
- Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - Arvind Sonwane
- Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - Anuj Chauhan
- Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - Ranvir Singh
- Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - Pushpendra Kumar
- Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - Ramji Yadav
- Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - Mohd Baqir
- Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - Bharat Bhushan
- Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
| | - Om Prakash
- Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India
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Milk yield and reproductive performance of Holstein cows testing positive for bovine tuberculosis. Trop Anim Health Prod 2015; 47:1061-6. [PMID: 25894823 DOI: 10.1007/s11250-015-0828-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 04/06/2015] [Indexed: 10/23/2022]
Abstract
The objective of this study was to determine if high milk-yielding Holstein cows testing positive for bovine tuberculosis (bTB) are affected in their reproductive performance and milk yield. For this purpose, 1044 healthy cows and 105 bTB reactor cows were used. Tuberculosis reactor cows were from four large commercial dairy operations from the same region which were transferred from their barns to an isolated dairy facility. Cows free from this disease were placed in the same barn as the bTB reactor cows but in an isolated division and served as control animals. The analysis of variance with a general linear model for binary data showed that the reproductive performance of bTB reactors was impaired; overall pregnancy per artificial insemination differed (P < 0.05) between bTB reactor and non-reactor cows (16.9 vs. 20.7%). Cows that were TB reactors required 4.7 ± 2.9 services per pregnancy compared with 4.3 ± 2.8 for control cows (P > 0.05). The intervals between calving and conception were similar between bTB reactors (154 ± 78 days) and control animals (150 ± 80 days). Control cows tended (P = 0.08) to produce more milk than bTB reactors over a 305-day lactation (10,684 ± 1720 vs. 10,345 ± 1736; mean ± SD). Serum metabolites indicative of nutritional stress did not differ between bTB reactor and non-reactor cows. It was concluded that both reproductive performance and milk yield decreased marginally in bTB reactor cows, which explains the reluctance of milk producers to get rid of these animals.
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Genome-wide association study identifies novel loci associated with resistance to bovine tuberculosis. Heredity (Edinb) 2014; 112:543-51. [PMID: 24496092 PMCID: PMC3998787 DOI: 10.1038/hdy.2013.137] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 10/03/2013] [Accepted: 10/16/2013] [Indexed: 12/31/2022] Open
Abstract
Tuberculosis (TB) caused by Mycobacterium bovis is a re-emerging disease of livestock that is of major economic importance worldwide, as well as being a zoonotic risk. There is significant heritability for host resistance to bovine TB (bTB) in dairy cattle. To identify resistance loci for bTB, we undertook a genome-wide association study in female Holstein-Friesian cattle with 592 cases and 559 age-matched controls from case herds. Cases and controls were categorised into distinct phenotypes: skin test and lesion positive vs skin test negative on multiple occasions, respectively. These animals were genotyped with the Illumina BovineHD 700K BeadChip. Genome-wide rapid association using linear and logistic mixed models and regression (GRAMMAR), regional heritability mapping (RHM) and haplotype-sharing analysis identified two novel resistance loci that attained chromosome-wise significance, protein tyrosine phosphatase receptor T (PTPRT; P=4.8 × 10(-7)) and myosin IIIB (MYO3B; P=5.4 × 10(-6)). We estimated that 21% of the phenotypic variance in TB resistance could be explained by all of the informative single-nucleotide polymorphisms, of which the region encompassing the PTPRT gene accounted for 6.2% of the variance and a further 3.6% was associated with a putative copy number variant in MYO3B. The results from this study add to our understanding of variation in host control of infection and suggest that genetic marker-based selection for resistance to bTB has the potential to make a significant contribution to bTB control.
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Franco MMJ, Paes AC, Ribeiro MG, de Figueiredo Pantoja JC, Santos ACB, Miyata M, Leite CQF, Motta RG, Listoni FJP. Occurrence of mycobacteria in bovine milk samples from both individual and collective bulk tanks at farms and informal markets in the southeast region of Sao Paulo, Brazil. BMC Vet Res 2013; 9:85. [PMID: 23618368 PMCID: PMC3650655 DOI: 10.1186/1746-6148-9-85] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 04/13/2013] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Mycobacterium spp. is one of the most important species of zoonotic pathogens that can be transmitted from cattle to humans. The presence of these opportunistic, pathogenic bacteria in bovine milk has emerged as a public-health concern, especially among individuals who consume raw milk and related dairy products. To address this concern, the Brazilian control and eradication program focusing on bovine tuberculosis, was established in 2001. However, bovine tuberculosis continues to afflict approximately 1,3 percent of the cattle in Brazil. In the present study, 300 samples of milk from bovine herds, obtained from both individual and collective bulk tanks and informal points of sale, were cultured on Löwenstein-Jensen and Stonebrink media. Polymerase chain reaction (PCR)-based tests and restriction-enzyme pattern analysis were then performed on the colonies exhibiting phenotypes suggestive of Mycobacterium spp., which were characterized as acid-fast bacilli. RESULTS Of the 300 bovine milk samples that were processed, 24 were positively identified as Mycobacterium spp.Molecular identification detected 15 unique mycobacterial species: Mycobacterium bovis, M. gordonae, M. fortuitum, M. intracellulare, M. flavescens, M. duvalii, M. haemophilum, M. immunogenum, M. lentiflavum, M. mucogenicum, M. novocastrense, M. parafortuitum, M. smegmatis, M. terrae and M. vaccae. The isolation of bacteria from the various locations occurred in the following proportions: 9 percent of the individual bulk-tank samples, 7 percent of the collective bulk-tank samples and 8 percent of the informal-trade samples. No statistically significant difference was observed between the presence of Mycobacterium spp. in the three types of samples collected, the milk production profiles, the presence of veterinary assistance and the reported concerns about bovine tuberculosis prevention in the herds. CONCLUSION The microbiological cultures associated with PCR-based identification tests are possible tools for the investigation of the presence of Mycobacterium spp. in milk samples. Using these methods, we found that the Brazilian population may be regularly exposed to mycobacteria by consuming raw bovine milk and related dairy products. These evidences reinforces the need to optimize quality programs of dairy products, to intensify the sanitary inspection of these products and the necessity of further studies on the presence of Mycobacterium spp. in milk and milk-based products.
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Affiliation(s)
- Marília Masello Junqueira Franco
- Department of Veterinary Hygiene and Public Health, School of Veterinary Medicine and Animal Science, UNESP – Univ Estadual Paulista, Box 56018618-970, Botucatu, State of Sao Paulo, Brazil
| | - Antonio Carlos Paes
- Department of Veterinary Hygiene and Public Health, School of Veterinary Medicine and Animal Science, UNESP – Univ Estadual Paulista, Box 56018618-970, Botucatu, State of Sao Paulo, Brazil
| | - Márcio Garcia Ribeiro
- Department of Veterinary Hygiene and Public Health, School of Veterinary Medicine and Animal Science, UNESP – Univ Estadual Paulista, Box 56018618-970, Botucatu, State of Sao Paulo, Brazil
| | - José Carlos de Figueiredo Pantoja
- Department of Veterinary Hygiene and Public Health, School of Veterinary Medicine and Animal Science, UNESP – Univ Estadual Paulista, Box 56018618-970, Botucatu, State of Sao Paulo, Brazil
| | - Adolfo Carlos Barreto Santos
- Laboratory of Micobacteriology, School of Pharmacy Sciences, UNESP – Univ Estadual Paulista, 14800-901, Araraquara, State of Sao Paulo, Brazil
| | - Marcelo Miyata
- Laboratory of Micobacteriology, School of Pharmacy Sciences, UNESP – Univ Estadual Paulista, 14800-901, Araraquara, State of Sao Paulo, Brazil
| | - Clarice Queico Fujimura Leite
- Laboratory of Micobacteriology, School of Pharmacy Sciences, UNESP – Univ Estadual Paulista, 14800-901, Araraquara, State of Sao Paulo, Brazil
| | - Rodrigo Garcia Motta
- Department of Veterinary Hygiene and Public Health, School of Veterinary Medicine and Animal Science, UNESP – Univ Estadual Paulista, Box 56018618-970, Botucatu, State of Sao Paulo, Brazil
| | - Fernando José Paganini Listoni
- Department of Veterinary Hygiene and Public Health, School of Veterinary Medicine and Animal Science, UNESP – Univ Estadual Paulista, Box 56018618-970, Botucatu, State of Sao Paulo, Brazil
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Herd-level risk factors for bovine tuberculosis: a literature review. Vet Med Int 2012; 2012:621210. [PMID: 22966479 PMCID: PMC3395266 DOI: 10.1155/2012/621210] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 04/14/2012] [Indexed: 11/17/2022] Open
Abstract
Bovine tuberculosis (TB), caused by Mycobacterium bovis, is one of the most challenging endemic diseases currently facing government, the veterinary profession, and the farming industry in the United Kingdom and Ireland and in several other countries. The disease has a notoriously complex epidemiology; the scientific evidence supports both cattle-cattle and wildlife-cattle transmission routes. To produce more effective ways of reducing such transmission, it is important to understand those risk factors which influence the presence or absence of bovine TB in cattle herds. Here we review the literature on herd-level risk factor studies. Whilst risk factors operate at different scales and may vary across regions, epidemiological studies have identified a number of risk factors associated with bovine TB herd breakdowns, including the purchase of cattle, the occurrence of bovine TB in contiguous herds, and/or the surrounding area as well as herd size. Other factors identified in some studies include farm and herd management practices, such as, the spreading of slurry, the use of certain housing types, farms having multiple premises, and the use of silage clamps. In general, the most consistently identified risk factors are biologically plausible and consistent with known transmission routes involving cattle-cattle and wildlife-cattle pathways.
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Bovine tuberculosis and udder health in Irish dairy herds. Vet J 2011; 192:71-4. [PMID: 21592829 DOI: 10.1016/j.tvjl.2011.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Revised: 03/15/2011] [Accepted: 04/01/2011] [Indexed: 11/21/2022]
Abstract
The association between bovine tuberculosis (TB) infection status based on results from the single intradermal comparative tuberculin test (SICTT) and milk production has been described in dairy cows in TB-infected herds in Ireland. The biological basis was uncertain, but could be related to increased TB susceptibility among lower producing dairy cows. In this study, the relationship between somatic cell count (as an objective measure of udder health) and SICTT reactivity (as a proxy for TB infection status) was investigated. Somatic cell counts of TB infected cows, both during and prior to the lactation of diagnosis of TB infection, were examined and compared to non-infected cows. All Irish dairy herds restricted from trading between June 2004 and May 2005 as a result of two or more TB reactors (test positive) to the SICTT were considered for study. Data were collected on 4340 cows from 419 herds. Previous lactation data for the cows were taken into consideration and all lactations on a cow were analysed together with the years of lactations. There was an inherent hierarchical structure in the data, with lactations nested within cows and cows within herds and so a linear mixed model with two random effects was used to describe the data. Milk production (305-day milk yield) was also included in the model as a fixed effect. The results of the study showed that for all lactations and years under investigation, somatic cell counts for SICTT reactor cows when compared to the non-reactor cows were not significantly different. In this study population, TB infection status was not associated with udder health.
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Skuce RA, Mallon TR, McCormick CM, McBride SH, Clarke G, Thompson A, Couzens C, Gordon AW, McDowell SWJ. Mycobacterium bovis genotypes in Northern Ireland: herd-level surveillance (2003 to 2008). Vet Rec 2011; 167:684-9. [PMID: 21257483 DOI: 10.1136/vr.c5108] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Surveillance genotyping (variable number tandem repeat profiling and spoligotyping) of Mycobacterium bovis isolates from culture-confirmed bovine tuberculosis (TB)-affected herds in Northern Ireland is presented for the years 2003 to 2008 inclusive. A total of 175 M bovis genotypes were identified in 8630 isolates from 6609 herds. On average, 73 genotypes were identified each year, with 29 genotypes present in all six years. Highly significant differences (P<0.0001) were observed between the relative frequency of some genotypes in the years 2003 to 2008. The spatial distribution of M bovis genotypes was not random (P<0.0001). Significant geographical localisation of M bovis genotypes was evident, suggesting that sources tended to be local. Despite regions being dominated by geographically localised genotypes, substantial and exploitable local diversity was still evident. Genotypes were also translocated significant distances from their normal geographical location.
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Affiliation(s)
- R A Skuce
- Veterinary Sciences Division, Agri-Food and Biosciences Institute, Stormont, Belfast BT4 3SD.
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Bermingham ML, More SJ, Good M, Cromie AR, Higgins IM, Berry DP. Genetic correlations between measures of Mycobacterium bovis infection and economically important traits in Irish Holstein-Friesian dairy cows. J Dairy Sci 2011; 93:5413-22. [PMID: 20965357 DOI: 10.3168/jds.2009-2925] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Accepted: 08/01/2010] [Indexed: 11/19/2022]
Abstract
Mycobacterium bovis is the primary agent of tuberculosis (TB) in cattle. The failure of Ireland and some other countries to reach TB-free status indicates a need to investigate complementary control strategies. One such approach would be genetic selection for increased resistance to TB. Previous research has shown that considerable genetic variation exists for susceptibility to the measures of M. bovis infection, confirmed M. bovis infection, and M. bovis-purified protein derivative (PPD) responsiveness. The objective of this study was to estimate the genetic and phenotypic correlations between economically important traits and these measures of M. bovis infection. A total of 20,148 and 17,178 cows with confirmed M. bovis infection and M. bovis-PPD responsiveness records, respectively, were available for inclusion in the analysis. First- to third-parity milk, fat, and protein yields, somatic cell count, calving interval, and survival, as well as first-parity body condition score records, were available on cows that calved between 1985 and 2007. Bivariate linear-linear and threshold-linear sire mixed models were used to estimate (co)variance components. The genetic correlations between economically important traits and the measures of M. bovis infection estimated from the linear-linear and threshold-linear sire models were similar. The genetic correlations between susceptibility to confirmed M. bovis infection and economically important traits investigated in this study were all close to zero. Mycobacterium bovis-PPD responsiveness was positively genetically correlated with fat production (0.39) and body condition score (0.36), and negatively correlated with somatic cell score (-0.34) and survival (-0.62). Hence, selection for increased survival may indirectly reduce susceptibility to M. bovis infection, whereas selection for reduced somatic cell count and increased fat production and body condition score may increase susceptibility to M. bovis infection.
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Affiliation(s)
- M L Bermingham
- Moorepark Production Research Centre, Fermoy, Co. Cork, Ireland.
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