Impacts of widespread badger culling on cattle tuberculosis: concluding analyses from a large-scale field trial.
Donnelly CA., Wei G., Johnston WT., Cox DR., Woodroffe R., Bourne FJ., Cheeseman CL., Clifton-Hadley RS., Gettinby G., Gilks P., Jenkins HE., Le Fevre AM., McInerney JP., Morrison WI.
BackgroundBovine tuberculosis (TB) has re-emerged as a major problem for British cattle farmers. Failure to control the infection has been linked to transmission from European badgers; badger culling has therefore formed a component of British TB control policy since 1973.Objectives and designTo investigate the impact of repeated widespread badger culling on cattle TB, the Randomised Badger Culling Trial compared TB incidence in cattle herds in and around ten culling areas (each 100 km2) with those in and around ten matched unculled areas.ResultsOverall, cattle TB incidence was 23.2% lower (95% confidence interval (CI) 12.4-32.7% lower) inside culled areas, but 24.5% (95% CI 0.6% lower-56.0% higher) higher on land ConclusionsCareful consideration is needed to determine in what settings systematic repeated culling might be reliably predicted to be beneficial, and in these cases whether the benefits of such culling warrant the costs involved.