Uptake of baits by wild badgers: Influences of deployment method, badger age and activity patterns on potential delivery of an oral vaccine

Andrew Robertson; Kate L Palphramand; Robbie A McDonald; Sonya Middleton; Mark A Chambers; Richard J Delahay; Stephen P Carter

doi:10.1016/j.prevetmed.2022.105702

Uptake of baits by wild badgers: Influences of deployment method, badger age and activity patterns on potential delivery of an oral vaccine

Prev Vet Med. 2022 Sep:206:105702. doi: 10.1016/j.prevetmed.2022.105702. Epub 2022 Jun 30.

Authors

Andrew Robertson¹, Kate L Palphramand², Robbie A McDonald³, Sonya Middleton⁴, Mark A Chambers⁵, Richard J Delahay², Stephen P Carter⁶

Affiliations

¹ Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall TR10 9FE, UK; National Wildlife Management Centre, Animal and Plant Health Agency, Woodchester Park, Gloucestershire GL10 3UJ, UK. Electronic address: a.robertson@exeter.ac.uk.
² National Wildlife Management Centre, Animal and Plant Health Agency, Woodchester Park, Gloucestershire GL10 3UJ, UK.
³ Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall TR10 9FE, UK.
⁴ Previously, Department of Bacteriology, Animal and Plant Health Agency, Weybridge, Woodham Lane, New Haw, Surrey KT15 3NB, UK.
⁵ Previously, Department of Bacteriology, Animal and Plant Health Agency, Weybridge, Woodham Lane, New Haw, Surrey KT15 3NB, UK; Currently, Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK.
⁶ National Wildlife Management Centre, Animal and Plant Health Agency, Woodchester Park, Gloucestershire GL10 3UJ, UK; Vincent Wildlife Trust, Eastnor, Ledbury, Herefordshire HR8 1EP, UK.

PMID: 35797823
DOI: 10.1016/j.prevetmed.2022.105702

Abstract

In parts of the United Kingdom and Ireland, the European badger is a wildlife host for Mycobacterium bovis (the causative agent of bovine tuberculosis). Badger vaccination is one management option for reducing disease spread. Vaccination is currently achieved by parenteral vaccination of captured badgers, but an oral vaccine delivered in a bait may provide an additional approach in the future. We conducted two field experiments in wild badger populations to identify factors that influence uptake (% of individuals with evidence of bait consumption) of candidate oral vaccine baits. In both instances, baits containing the biomarker iophenoxic acid (as a proxy for the vaccine) were fed at burrows (setts) associated with badger social groups (study A = 48 groups, study B = 40 groups). Badgers were captured following a period of bait deployment to quantify uptake in relation to age, sex and social group. In addition, groups were allocated different treatments and the bait deployment protocol was varied to identify effects on uptake. Study A tested the effects of season, bait type, bait placement and packaging, while study B investigated the effects of bait quantity and badger activity levels. Overall bait uptake was low (Study A = 24 %, Study B = 37 %) but this varied among treatment groups (range 0-58 %). In both studies, bait uptake was significantly higher in cubs than in adults. Uptake was substantially higher where baits were placed directly into sett entrances (rather than under tiles near setts), and by badgers caught at main setts rather than at outlier setts. Season, bait type and packaging did not influence uptake, while increasing the quantity of bait available increased uptake by cubs but not by adults. Levels of badger activity at setts varied over time (suggesting potential disturbance), but were positively associated with levels of bait uptake.

Keywords: BCG; Badger; Bait uptake; Bovine tuberculosis; Oral vaccination; Wildlife disease.

MeSH terms

Animals
Animals, Wild
BCG Vaccine
Cattle
Cattle Diseases*
Mustelidae* / microbiology
Mycobacterium bovis*
Tuberculosis, Bovine* / microbiology
Tuberculosis, Bovine* / prevention & control
Vaccination / methods
Vaccination / veterinary

Substances

BCG Vaccine