LAUSR

The incidence of bovine tuberculosis (TB, caused by Mycobacterium bovis) in cattle has been associated with TB in badgers (Meles meles) in parts of England. The aim was to identify badger associated M. bovis reservoirs in the Edge Area, between the High and Low Risk Areas for cattle TB. Data from badger TB surveys were sparse. Therefore, a definition for a local M. bovis reservoir potentially shared by cattle and badgers was developed using cattle TB surveillance data. The performance of the definition was estimated through Latent Class Analysis using badger TB survey data. Spatial units (25 km2 ) in the Edge Area were classified as having a reservoir if they had i) at least one TB incident in at least three of the previous seven years ii) at least one TB incident in a cattle herd confirmed by post-mortem tests as due to M. bovis infection and not attributable to cattle movements in the previous two years and iii) more confirmed TB incidents than un-confirmed in the previous two years. Approximately twenty percent of the Edge Area was classified as having a local M. bovis reservoir using the cattle-based definition. Assuming 15% TB prevalence in Edge Area badgers, sensitivity for the local M. bovis reservoir definition varied from 25.7% (95% Credible Interval (CrI) 10.7 to 85.1 %) to 64.8 % (95% CrI 48.1 to 88.0 %). Specificity was 91.9% (CrI 83.6 to 97.4 %). Over ninety percent of the local reservoir was in stable endemic TB areas identified through previous work and its spatial distribution was largely consistent with local veterinary knowledge. Uncertainty in the reservoir spatial distribution was explored through its recalculation in spatial units shifted in different directions. We recommend that the definition is re-evaluated as further data on badger infection with M. bovis becomes available. This article is protected by copyright. All rights reserved.