Effect of selective removal of badgers (Meles meles) on ranging behaviour during a 'Test and Vaccinate or Remove' intervention in Northern Ireland.

The role of the Eurasian badger (Meles meles) as a wildlife host has complicated the management of bovine tuberculosis (bTB) in cattle. Badger ranging behaviour has previously been found to be altered by culling of badgers and has been suggested to increase the transmission of bTB either among badgers or between badgers and cattle. In 2014, a five-year bTB intervention research project in a 100 km2 area in Northern Ireland was initiated involving selective removal of dual path platform (DPP) VetTB (immunoassay) test positive badgers and vaccination followed by release of DPP test negative badgers ('Test and Vaccinate or Remove'). Home range sizes, based on position data obtained from global positioning system collared badgers, were compared between the first year of the project, where no DPP test positive badgers were removed, and follow-up years 2-4 when DPP test positive badgers were removed. A total of 105 individual badgers were followed over 21 200 collar tracking nights. Using multivariable analyses, neither annual nor monthly home ranges differed significantly in size between years, suggesting they were not significantly altered by the bTB intervention that was applied in the study area.

Evaluating the application of the dual path platform VetTB test for badgers (Meles meles) in the test and vaccinate or remove (TVR) wildlife research intervention project in Northern Ireland.

European badgers (Meles meles) are accepted as a wildlife reservoir host for Mycobacterium bovis, which causes bovine tuberculosis (bTB) in the British Isles. The objective of this study was to evaluate the use of Dual Path Platform (DPP) VetTB test (Chembio Diagnostic Systems Inc., Medford, NY, USA) within a Test and Vaccinate or Remove (TVR) wildlife research intervention project. Blood samples were collected from 456 individual badgers, trapped in 2015 and 2016, and tested in the field with DPP VetTB test using whole blood. Additionally, whole blood and serum samples were taken to the laboratory for further DPP VetTB testing and for gamma interferon (IFN-γ) testing. Swabs were taken from the oropharynx and trachea and submitted for bacteriological culture as were swabs from wounds, if present. Field DPP VetTB test positive badgers were euthanised and underwent post-mortem examination and bTB confirmatory testing. The results demonstrated that the test performed as well in the field using whole blood as DPP Vet TB tests in the laboratory using sera or whole blood, and as well as other established tests for M. bovis. Visual assessment of the DPP VetTB test using serum under laboratory conditions showed a high degree of consistency between raters. Using a relative gold standard (parallel interpretation of IFN-γ assay and oropharyngeal/tracheal sample/culture), sensitivity estimates for the DPP VetTB test using sera and whole blood were 0.5 (95%CI 0.34-0.66) and 0.42 (95%CI 0.24-0.66), respectively. Specificity estimates were 0.95 (95%CI 0.93-0.97) for sera and 0.89 (95%CI 0.86-0.92) for whole blood. Parallel interpretation of Band 1 (MPB83) and Band 2 (CFP-10/ESAT-6) of the DPP VetTB test was not superior to interpretation of Band 1 only. The results give confidence in the reliability and reproducibility of the DPP VetTB test for badgers under field conditions and therefore it is considered appropriate for use in a badger bTB control campaign.