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

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.

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Decision tree machine learning applied to bovine tuberculosis risk factors to aid disease control decision making

Preventive Veterinary Medicine ◽

10.1016/j.prevetmed.2019.104860 ◽

2020 ◽

Vol 175 ◽

pp. 104860 ◽

Cited By ~ 3

Author(s):

M. Pilar Romero ◽

Yu-Mei Chang ◽

Lucy A. Brunton ◽

Jessica Parry ◽

Alison Prosser ◽

...

Keyword(s):

Machine Learning ◽

Risk Factors ◽

Decision Making ◽

Decision Tree ◽

Disease Control ◽

Bovine Tuberculosis ◽

Control Decision ◽

Tuberculosis Risk

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New Assessment of Bovine Tuberculosis Risk Factors in Belgium Based on Nationwide Molecular Epidemiology

Journal of Clinical Microbiology ◽

10.1128/jcm.00293-10 ◽

2010 ◽

Vol 48 (8) ◽

pp. 2802-2808 ◽

Cited By ~ 27

Author(s):

M.- F. Humblet ◽

M. Gilbert ◽

M. Govaerts ◽

M. Fauville-Dufaux ◽

K. Walravens ◽

...

Keyword(s):

Risk Factors ◽

Molecular Epidemiology ◽

Bovine Tuberculosis ◽

Tuberculosis Risk

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

Preventive Veterinary Medicine ◽

10.1016/j.prevetmed.2016.07.006 ◽

2016 ◽

Vol 131 ◽

pp. 31-40 ◽

Cited By ~ 4

Author(s):

Maud Marsot ◽

Marina Béral ◽

Axelle Scoizec ◽

Yoann Mathevon ◽

Benoit Durand ◽

...

Keyword(s):

Risk Factors ◽

Bovine Tuberculosis ◽

Herd Level ◽

Cattle Herds

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Risk factors and true prevalence of bovine tuberculosis in Bangladesh

PLoS ONE ◽

10.1371/journal.pone.0247838 ◽

2021 ◽

Vol 16 (2) ◽

pp. e0247838

Author(s):

Md. Nazimul Islam ◽

Mohammad Kamruzzaman Khan ◽

Mohammad Ferdousur Rahman Khan ◽

Polychronis Kostoulas ◽

A. K. M. Anisur Rahman ◽

...

Keyword(s):

Risk Factors ◽

Bovine Tuberculosis ◽

Critical Threshold ◽

Bayesian Hierarchical ◽

Herd Level ◽

Control Programs ◽

True Prevalence ◽

Apparent Prevalence ◽

Risk Factor Data ◽

Factor Data

Bovine tuberculosis (bTb) is endemic in Bangladesh but the true prevalence has not yet been reported. Our objectives for this study were to determine the true prevalence and identify risk factors for bTb at the animal- and herd-level in Bangladesh. A total of 510 cows were randomly selected during January 2018 to December 2018. Caudal fold (CFT) and comparative cervical tuberculin tests (CCT) were serially interpreted. Animal- and herd-level risk factor data were collected using a pre-tested questionnaire. The hierarchical true prevalence of bTb was estimated within a Bayesian framework. The herd- and animal-level risk factors were identified using mixed effects logistic regression. The apparent prevalence of bTb was 20.6% [95% Confidence Interval (CI): 17.3; 24.3] based on CFT. The animal-level true prevalence of bTb was 21.9 (13.0; 32.4). The herd-level true prevalence in different regions varied from 41.9% to 88.8%. The region-level true prevalence was 49.9 (13.8; 91.2). There is a 100% certainty that herds from Bhaluka and Mymensingh Sadar upazilas are not free from bTb. The odds of bTb were 3.9 times (1.2; 12.6) higher in herds having more than four cows than those with ≤ 4 cows. On the other hand, the risk of bTb was 3.3 times higher (1.0; 10.5) in non-grazing cows than grazing cows. Crossbred cows were 2.9 times (1.5; 5.9) more likely to be infected with bTb than indigenous cows. The risk of bTb in animals with cough was 2.3 times (1.2; 4.3) higher than those without cough. Crossbred, non-grazing cows with cough should be targeted for bTb surveillance. Herds of the Mymensingh, Sadar and Bhaluka regions should be emphasized for bTb control programs. Estimation of Bayesian hierarchical true prevalence facilitates identification of areas with higher prevalence and can be used to indicate regions that where true prevalence exceeds a pre-specified critical threshold.

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Herd-level risk factors for bovine tuberculosis and adoption of related biosecurity measures in Northern Ireland: A case-control study

The Veterinary Journal ◽

10.1016/j.tvjl.2016.03.021 ◽

2016 ◽

Vol 213 ◽

pp. 26-32 ◽

Cited By ~ 16

Author(s):

M.J.H. O'Hagan ◽

D.I. Matthews ◽

C. Laird ◽

S.W.J. McDowell

Keyword(s):

Risk Factors ◽

Northern Ireland ◽

Bovine Tuberculosis ◽

Case Control Study ◽

Case Control ◽

Herd Level ◽

Control Study

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Bovine tuberculosis prevalence and risk factors in selected districts of Bangladesh

PLoS ONE ◽

10.1371/journal.pone.0241717 ◽

2020 ◽

Vol 15 (11) ◽

pp. e0241717

Author(s):

S. K. Shaheenur Islam ◽

Tanzida Begum Rumi ◽

S. M. Lutful Kabir ◽

Adri G. M. van der Zanden ◽

Vivek Kapur ◽

...

Keyword(s):

Risk Factors ◽

Bovine Tuberculosis ◽

Multivariable Analysis ◽

Herd Size ◽

Farm Size ◽

Age Group ◽

Cross Sectional Survey ◽

Mixed Effect ◽

Herd Level ◽

Pregnancy Status

A cross-sectional survey was conducted in selected districts of Bangladesh to estimate the prevalence of bovine tuberculosis (bTB), and to identify the risk factors for bTB. We included 1865 farmed cattle from 79 herds randomly selected from five districts. Herd and animal level data were collected using semi-structured interviews with cattle herd owners. The single intradermal comparative tuberculin test (SICTT) was used to estimate the prevalence of bTB. The risk factors were identified using mixed-effect multiple logistic regression analyses. The overall herd and animal level prevalences of bTB were estimated to be 45.6% (95% Confidence Interval [CI] = 34.3–57.2%) and 11.3 (95% CI = 9.9–12.8%), respectively, using the OIE recommended >4 mm cut-off. The true animal level prevalence of bTB was estimated to be 11.8 (95% Credible Interval = 2.1–20.3%). At the herd level, farm size, bTB history of the farm and type of husbandry were significantly associated with bTB status in univariable analysis. Similarly, age group, sex, pregnancy status and parity were significantly associated with bTB at cattle level. However, in multivariable analysis only herd size at the herd level and age group and pregnancy status at the cattle level were significant. Compared to a herd size of 1–10, the odds of bTB were 22.8 (95% CI: 5.2–100.9) and 45.6 times (95% CI: 5.0–417.7) greater in herd sizes of >20–50 and >50, respectively. The odds of bTB were 2.2 (95% CI: 1.0–4.5) and 2.5 times (95% CI: 1.1–5.4) higher in cattle aged >3–6 years and > 6 years, compared to cattle aged ≤1 year. Pregnancy increased the odds of bTB by 1.7 times (95% CI: 1.2–2.4) compared to non-pregnant cattle. Taken together, the results suggest high herd and animal level prevalence of bTB in these 5 districts, with the greatest risk of bTB in older and pregnant cattle within large herds (>20), and highlight an urgent need for continued surveillance and implementation of bTB control programs in Bangladesh.

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Corrigendum to “Decision tree machine learning applied to bovine tuberculosis risk factors to aid disease control decision making” [Prev. Vet. Med. 175 (2020) 104860]

Preventive Veterinary Medicine ◽

10.1016/j.prevetmed.2019.104879 ◽

2020 ◽

Vol 175 ◽

pp. 104879

Author(s):

M. Pilar Romero ◽

Yu-Mei Chang ◽

Lucy A. Brunton ◽

Jessica Parry ◽

Alison Prosser ◽

...

Keyword(s):

Machine Learning ◽

Risk Factors ◽

Decision Making ◽

Decision Tree ◽

Disease Control ◽

Bovine Tuberculosis ◽

Control Decision ◽

Tuberculosis Risk

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Herd-Level Risk Factors for Bovine Tuberculosis: A Literature Review

Veterinary Medicine International ◽

10.1155/2012/621210 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10 ◽

Cited By ~ 65

Author(s):

Robin A. Skuce ◽

Adrian R. Allen ◽

Stanley W. J. McDowell

Keyword(s):

Risk Factors ◽

Bovine Tuberculosis ◽

Management Practices ◽

Scientific Evidence ◽

Epidemiological Studies ◽

Herd Size ◽

Herd Level ◽

Endemic Diseases ◽

Veterinary Profession ◽

Cattle Herds

Bovine tuberculosis (TB), caused byMycobacterium 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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