Bovine Tuberculosis (Mycobacterium bovis) Outbreak Duration in Cattle Herds in Ireland: A Retrospective Observational Study

Bovine tuberculosis (bTB) outbreaks, caused by Mycobacterium bovis infection, are a costly animal health challenge. Understanding factors associated with the duration of outbreaks, known as breakdowns, could lead to better disease management policy development. We undertook a retrospective observational study (2012–2018) and employed Finite Mixture Models (FMM) to model the outcome parameter, and to investigate how factors were associated with duration for differing subpopulations identified. In addition to traditional risk factors (e.g., herd size, bTB history), we also explored farm geographic area, parcels/farm fragmentation, metrics of intensity via nitrogen loading, and whether herds were designated controlled beef finishing units (CBFU) as potential risk factors for increased duration. The final model fitted log-normal distributions, with two latent classes (k) which partitioned the population into a subpopulation around the central tendency of the distribution, and a second around the tails of the distribution. The latter subpopulation included longer breakdowns of policy interest. Increasing duration was positively associated with recent (<3 years) TB history and the number of reactors disclosed, (log) herd size, beef herd-type relative to other herd types, number of land parcels, area, being designated a CBFU (“feedlot”) and having high annual inward cattle movements within the “tails” subpopulation. Breakdown length was negatively associated with the year of commencement of breakdown (i.e., a decreasing trend) and non-significantly with the organic nitrogen produced on the farm (N kg/hectare), a measure of stocking density. The latter finding may be due to confounding effects with herd size and area. Most variables contributed only moderately to explaining variation in breakdown duration, that is, they had moderate size effects on duration. Herd-size and CBFU had greater effect sizes on the outcome. The findings contribute to evidence-based policy formation in Ireland.

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Bovine Tuberculosis (Mycobacterium bovis) Outbreak Duration in Cattle Herds in Ireland: A Retrospective Observational Study

10.20944/preprints202008.0634.v1 ◽

2020 ◽

Author(s):

Andrew William Byrne ◽

Damien Barrett ◽

Philip Breslin ◽

Jamie Madden ◽

James O'Keeffe ◽

...

Keyword(s):

Risk Factors ◽

Observational Study ◽

Mycobacterium Bovis ◽

Bovine Tuberculosis ◽

Animal Health ◽

Herd Size ◽

Policy Formation ◽

Nitrogen Loading ◽

Management Policy ◽

Retrospective Observational Study

Bovine tuberculosis (bTB) outbreaks, caused by Mycobacterium bovis infection, are a costly animal health challenge. Understanding factors associated with the duration of outbreaks, known as breakdowns, could lead to better disease management policy development. We undertook a retrospective observational study (2012-2018) and employed Finite Mixture Models (FMM) to model the outcome parameter, and to investigate how factors were associated with duration for differing subpopulations identified. In addition to traditional risk factors (e.g. herd size, bTB history), we also explored farm geographic area, parcels/farm fragmentation, metrics of intensity via nitrogen loading, and whether herds were designated controlled beef finishing units (CBFU) as potential risk factors for increased duration. The final model fitted log-normal distributions, with two latent classes (k) which partitioned the population into a subpopulation around the central tendency of the distribution, and a second around the tails of the distribution. The latter subpopulation included longer breakdowns of policy interest. Increasing duration was positively associated with recent (<3 yrs) TB history and the number of reactors disclosed, (log) herd size, beef herd-type relative to other herd types, number of land parcels, area, and being designated a controlled finishing unit (“feedlot”), and having high annual inward cattle movements within the “tails” subpopulation. Breakdown length was negatively associated with year of commencement of breakdown (i.e. a decreasing trend) and non-significantly with the organic nitrogen produced on the farm (N kg/hectare), a measure of stocking density. The latter finding may be due to confounding effects with herd size and area. Most variables contributed only moderately to explaining variation in breakdown duration, that is, they had moderate size effects on duration. Herd-size and CBFU had greater effect sizes on the outcome. The findings contribute to evidence-based policy formation in Ireland.

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Hemmkörperentwicklung bei Hämophilie-Patienten nach Präparate wechsel

Hämostaseologie ◽

10.1055/s-0037-1619773 ◽

2012 ◽

Vol 32 (S 01) ◽

pp. S39-S42 ◽

Cited By ~ 1

Author(s):

S. Kocher ◽

G. Asmelash ◽

V. Makki ◽

S. Müller ◽

S. Krekeler ◽

...

Keyword(s):

Risk Factors ◽

Risk Factor ◽

Observational Study ◽

Retrospective Observational Study ◽

Frequent Change ◽

Patient Age ◽

Treatment Regimens ◽

Patient Âgé ◽

The Relationship ◽

Observation Period

SummaryThe retrospective observational study surveys the relationship between development of inhibitors in the treatment of haemophilia patients and risk factors such as changing FVIII products. A total of 119 patients were included in this study, 198 changes of FVIII products were evaluated. Results: During the observation period of 12 months none of the patients developed an inhibitor, which was temporally associated with a change of FVIII products. A frequent change of FVIII products didn’t lead to an increase in inhibitor risk. The change between plasmatic and recombinant preparations could not be confirmed as a risk factor. Furthermore, no correlation between treatment regimens, severity, patient age and comorbidities of the patients could be found.

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Risk Factors and Scoring System of Cage Retropulsion after Posterior Lumbar Interbody Fusion: A Retrospective Observational Study

Orthopaedic Surgery ◽

10.1111/os.12987 ◽

2021 ◽

Author(s):

Lei Peng ◽

Jiang Guo ◽

Ji‐ping Lu ◽

Song Jin ◽

Peng Wang ◽

...

Keyword(s):

Risk Factors ◽

Observational Study ◽

Scoring System ◽

Interbody Fusion ◽

Posterior Lumbar Interbody Fusion ◽

Retrospective Observational Study ◽

Lumbar Interbody Fusion

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Evaluating the Bovine Tuberculosis Eradication Mechanism and Its Risk Factors in England’s Cattle Farms

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18073451 ◽

2021 ◽

Vol 18 (7) ◽

pp. 3451

Author(s):

Tabassom Sedighi ◽

Liz Varga

Keyword(s):

Risk Factors ◽

Bovine Tuberculosis ◽

Animal Health ◽

Dynamic Bayesian Network ◽

Policy Makers ◽

Domain Experts ◽

Actual Experience ◽

Complex Evaluation ◽

Risk Areas ◽

Cattle Farms

Controlling bovine tuberculosis (bTB) disease in cattle farms in England is seen as a challenge for farmers, animal health, environment and policy-makers. The difficulty in diagnosis and controlling bTB comes from a variety of factors: the lack of an accurate diagnostic test which is higher in specificity than the currently available skin test; isolation periods for purchased cattle; and the density of active badgers, especially in high-risk areas. In this paper, to enable the complex evaluation of bTB disease, a dynamic Bayesian network (DBN) is designed with the help of domain experts and available historical data. A significant advantage of this approach is that it represents bTB as a dynamic process that evolves periodically, capturing the actual experience of testing and infection over time. Moreover, the model demonstrates the influence of particular risk factors upon the risk of bTB breakdown in cattle farms.

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