scholarly journals Relative Contribution of Each Component of the French Ante-Mortem Surveillance System for Bovine Tuberculosis in Its Overall Sensitivity

2021 ◽  
Vol 9 (3) ◽  
pp. 643
Author(s):  
Valentine Guétin-Poirier ◽  
Julie Rivière ◽  
Barbara Dufour
Keyword(s):  
Bovine Tuberculosis ◽  
Surveillance System ◽  
Local Scale ◽  
Scenario Tree ◽  
Epidemiological Investigation ◽  
Infected Herd ◽  
Herd Level ◽  
Relative Contribution ◽  
Tree Modeling

The aim of this study was to assess the contribution to the sensitivity of the French ante-mortem surveillance system for bovine tuberculosis in cattle of each of the system’s components (periodic screening, epidemiological investigations, and screening exchanged animals), on a local scale defined by administrative areas. These components were individually assessed in previous studies by scenario tree modeling. We used scenario tree modeling at the herd level and combined the results to evaluate the overall sensitivity of the ante-mortem surveillance system. The probability to detect at least one infected herd was consistent with the location of the outbreaks detected in 2016. In areas with a high apparent incidence, the probability of an infected herd to be detected was satisfactory (for an infected herd there was a 100% probability to be detected over a two-year period). Periodic screening was the most important component for the overall sensitivity in infected areas. In other areas, where periodic screening had stopped, tracing-on epidemiological investigation was the most sensitive component of the system. Screening exchanged animals had a negligible part in the overall sensitivity of the surveillance system.

Assessment of the sensitivity of the bovine tuberculosis eradication program in a high prevalence region of Spain using scenario tree modeling

2019 ◽  
Vol 173 ◽  
pp. 104800 ◽  
Author(s):  
Maria Luisa de la Cruz ◽  
Pilar Pozo ◽  
Anna Grau ◽  
Jesus Nacar ◽  
Javier Bezos ◽  
...  
Keyword(s):  
Bovine Tuberculosis ◽  
Scenario Tree ◽  
Eradication Program ◽  
High Prevalence ◽  
Tree Modeling

scholarly journals Prevalence and herd-level risk factors of bovine tuberculosis in the State of Goiás, Brazil

2016 ◽  
Vol 37 (5Supl2) ◽  
pp. 3625 ◽  
Author(s):  
Willian Vilela Rocha ◽  
Valéria De Sá Jayme ◽  
Ana Lourdes Arrais de Alencar Mota ◽  
Wilia Marta Elsner Diederichsen de Brito ◽  
Glauciane Ribeiro de Castro Pires ◽  
...  
Keyword(s):  
Risk Factors ◽  
Bovine Tuberculosis ◽  
Protective Factor ◽  
Management Practices ◽  
Multiple Logistic Regression Analysis ◽  
Livestock Production ◽  
The State ◽  
Economic Losses ◽  
Strong Concentration ◽  
Herd Level

Bovine tuberculosis results in economic losses in livestock production and poses a risk to public health. This study aimed to characterize the epidemiological status of bovine tuberculosis in adult cows in the state of Goiás, Brazil. The state was divided into three sampling strata, corresponding to different livestock production circuits. A total of 18,659 animals were tested with the comparative cervical tuberculin test (CCT), in 300 randomly sampled bovine herds per stratum. An epidemiological questionnaire was used to identify health and management practices that may be associated with the presence of tuberculosis infection in the herd. In Stratum 1, dominated by beef cattle, no animals reacted to the CCT. In Stratum 2, which covers the main dairy regions of the state, the prevalence was estimated at 8.67% [5.73 to 12.74%] for herds and at 0.9% [0.21 to 1.58%] for animals. In Stratum 3, characterized by a mix of dairy, beef and dual-purpose herds, the prevalence was estimated at 1.00% [0.21 to 2.89] for herds and 0.30% [0.10 to 0.49 %] for animals. The overall prevalence in the state of Goiás was 3.43% [2.20 to 4.67%] for herds and 0.30% [0.10 to 0.49%] for animals. The multiple logistic regression analysis revealed that herd-level risk factors associated with the presence of the bovine tuberculosis are: the location of the herd in Stratum 2 (OR = 12.05 [3.52 to 41.28]) and the number of times a cow is milked per day (OR = 6.27 [2.72 to 14.44]). Regular veterinary care was identified as a protective factor (OR = 0.38 [0.15-0.94]). These results indicate that bovine tuberculosis is endemic in the state; its spatial distribution is heterogeneous with a strong concentration in dairy regions. The most intensive dairy farms are those with the highest risk, which is consistent with what other authors’ found elsewhere in Brazil. The epidemiological information generated by this study provides information for planning of risk-based surveillance actions, and justifies the adoption of free-herd certification programs for bovine tuberculosis in the main dairy regions of Goiás.

Association between results of diagnostic tests for bovine tuberculosis and Johne’s disease in cattle

2019 ◽  
Vol 185 (22) ◽  
pp. 693-693 ◽  
Author(s):  
Catalina Picasso-Risso ◽  
Ana Grau ◽  
Douwe Bakker ◽  
Jesus Nacar ◽  
Olga Mínguez ◽  
...  
Keyword(s):  
Bovine Tuberculosis ◽  
Diagnostic Tests ◽  
Conditional Logistic Regression ◽  
Johne's Disease ◽  
Johne’S Disease ◽  
Effective Control ◽  
Mixed Effect ◽  
Intradermal Testing ◽  
Herd Level ◽  
The Impact

BackgroundBovine tuberculosis (bTB) diagnosis is impaired by numerous factors including cross-reactivity with Mycobacterium avium subspecies paratuberculosis, which causes Johne’s disease (JD). In addition, the effect of repeated bTB-intradermal testing on the performance of JD diagnostic tests is not fully understood. This study aimed to evaluate the impact of repeated bTB-intradermal tests under field conditions in Spain on the JD serological status of cattle.MethodsbTB-positive herds (n=264) from Castilla-y-Leon region were selected and matched with officially tuberculosis-free control herds. The association between JD and bTB status at the herd level was assessed using conditional logistic regression and, in herds with both JD-positive and bTB-positive animals, a Bayesian hierarchical mixed-effect model was used for individual-level analysis.ResultsA significantly higher risk of being JD positive (OR: 1.48; 95 per cent CI: 1.01 to 2.15) was found for bTB-positive herds compared with controls. Individual results indicated that cattle tested more than three times per year, within the last 90 days and more than 12 months were more likely to be JD positive. A skin test-related boost in antibody response could be the cause of an apparent increase of the sensitivity of the JD-absorbed ELISA.ConclusionThe results demonstrate the interaction between bTB repeated testing and JD individual and herd-level results and this improved knowledge will facilitate the design of more effective control programmes in herds coinfected with two of the most important endemic diseases affecting cattle in Spain.

Herd-level risk factors for bovine tuberculosis in French cattle herds

2016 ◽  
Vol 131 ◽  
pp. 31-40 ◽  
Author(s):  
Maud Marsot ◽  
Marina Béral ◽  
Axelle Scoizec ◽  
Yoann Mathevon ◽  
Benoit Durand ◽  
...  
Keyword(s):  
Risk Factors ◽  
Bovine Tuberculosis ◽  
Herd Level ◽  
Cattle Herds

scholarly journals Eradication of bovine tuberculosis at a herd-level in Madrid, Spain: study of within-herd transmission dynamics over a 12 year period

2012 ◽  
Vol 8 (1) ◽  
pp. 100 ◽  
Author(s):  
Julio Alvarez ◽  
Andres M Perez ◽  
Javier Bezos ◽  
Carmen Casal ◽  
Beatriz Romero ◽  
...  
Keyword(s):  
Bovine Tuberculosis ◽  
Transmission Dynamics ◽  
Herd Level

scholarly journals Herd-level bovine tuberculosis risk factors: assessing the role of low-level badger population disturbance

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
David M. Wright ◽  
Neil Reid ◽  
W. Ian Montgomery ◽  
Adrian R. Allen ◽  
Robin A. Skuce ◽  
...  
Keyword(s):  
Risk Factors ◽  
Bovine Tuberculosis ◽  
Herd Level ◽  
Low Level ◽  
Tuberculosis Risk

scholarly journals Exogenous disturbances and endogenous self-organized processes are not mutually exclusive drivers of spatial patterns in macroalgal assemblages

2020 ◽  
Author(s):  
J. He ◽  
L. Rindi ◽  
C. Mintrone ◽  
L. Benedetti-Cecchi
Keyword(s):  
Spatial Patterns ◽  
Empirical Work ◽  
Power Laws ◽  
Local Scale ◽  
Species Assemblages ◽  
Spatial Gradient ◽  
Gap Size ◽  
Scale Interactions ◽  
Relative Contribution ◽  
Self Organized

AbstractComplex spatial patterns are common in coastal marine systems, but mechanisms underlying their formation are disputed. Most empirical work has focused on exogeneous spatially structured disturbances as the leading cause of pattern formation in species assemblages. However, theoretical and observational studies suggest that complex spatial patterns, such as power laws in gap-size distribution, may result from endogenous self-organized processes involving local-scale interactions. The lack of studies simultaneously assessing the influence of spatially variable disturbances and local-scale interactions has fuelled the idea that exogenous and endogenous processes are mutually exclusive explanations of spatial patterns in marine ecosystems. To assess the relative contribution of endogenous and exogenous processes in the emergence of spatial patterns, an intertidal assemblage of algae and invertebrates was exposed for 2 years to various combinations of intensity and spatial patterns of disturbance. Localized disturbances impinging at the margins of previously disturbed clearings and homogenous disturbances without any spatial pattern generated heterogeneous distributions of disturbed gaps and macroalgal patches, characterized by a truncated or a pure power-law scaling. Spatially varying disturbances produced a spatial gradient in the distribution of algal patches and, to a lesser extent, also a power-scaling in both patch- and gap-size distributions. These results suggest that exogenous and endogenous processes are not mutually exclusive forces that can lead to the formation of similar spatial patterns in species assemblages.

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