The development of quantitative risk-based strategies for bovine Tuberculosis in England and Wales

Abstract

The aim of this project is to provide recommendations for improved surveillance for bovine Tuberculosis (bTB) in English and Welsh cattle, considering three important, distinct problems: 1. In areas where there is a low incidence (Low Risk Areas or LRAs) of bTB in cattle and the default testing regime is currently quadrennial, to identify approaches that will reduce the total testing burden, without compromising the detection of herds containing infected cattle and efficiently identify high risk herds, possibly for additional testing. 2. In areas where there is a high incidence (High Risk Areas or HRAs) of bTB in cattle, to identify approaches that more quickly identify herds which may present a higher risk of onward transmission to other herds. 3. In areas which are currently perceived as LRAs but are in danger of becoming HRAs (Transition Areas or TAs), to identify signatures of this transition, with an aim of informing increasing surveillance (i.e. moving from (1) above to (2)) and or systematically curtailing spread of HRAs themselves. The work to achieve these objectives was delivered in four separate stages: 1. Identification of areas that could be epidemiologically classified as HRA, LRA and TA. 2. Identification of statistical risk factors. 3. Identifying outcomes of revised surveillance strategies. 4. Within herd models of bTB transmission identified substantial detection delays that might result in breakdowns should infections be seeded in herds exempt from RHT.