Identifying genotype specific elevated-risk areas and associated herd risk factors for bovine tuberculosis spread in British cattle.
Epidemics 2018;
24:34-42. [PMID:
29548927 PMCID:
PMC6105618 DOI:
10.1016/j.epidem.2018.02.004]
[Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 02/14/2018] [Accepted: 02/20/2018] [Indexed: 11/06/2022] Open
Abstract
Bovine tuberculosis elevated-risk areas historically more extensive than thought.
Cattle movements alone do not explain spread of areas of elevated risk.
For all genotypes, the majority of infection spread is due to local effects.
Similar risk-factors identified within elevated-risk and transitional areas.
Risk factors key to identify incipient elevated-risk areas before incidence rising.
Bovine tuberculosis (bTB) is a chronic zoonosis with major health and economic impact on the cattle industry. Despite extensive control measures in cattle and culling trials in wildlife, the reasons behind the expansion of areas with high incidence of bTB breakdowns in Great Britain remain unexplained. By balancing the importance of cattle movements and local transmission on the observed pattern of cattle outbreaks, we identify areas at elevated risk of infection from specific Mycobacterium bovis genotypes. We show that elevated-risk areas (ERAs) were historically more extensive than previously understood, and that cattle movements alone are insufficient for ERA spread, suggesting the involvement of other factors. For all genotypes, we find that, while the absolute risk of infection is higher in ERAs compared to areas with intermittent risk, the statistically significant risk factors are remarkably similar in both, suggesting that these risk factors can be used to identify incipient ERAs before this is indicated by elevated incidence alone. Our findings identify research priorities for understanding bTB dynamics, improving surveillance and guiding management to prevent further ERA expansion.
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