Can biosecurity on farms reduce bovine tuberculosis risks in cattle in England? a review of observational and literature-based evidence
Voller C., Perrin LD., Gibbens JC., Delahay RJ., Heasman L., Vial F., Prosser A., Heard J., Robertson A., Brunton L., Enticott G., Donnelly C., Downs SH.
Background: Bovine tuberculosis (TB) is a burden to cattle farming in Great Britain. Poor biosecurity has been identified as contributing to the epidemic. Methods: We conducted a systematic review of epidemiological studies in the scientific literature (1921 – 2024) measuring the association between farm biosecurity and cattle TB. Eligible studies controlled for confounding and reported statistically significant association/s between biosecurity and TB (p<0.05) and/or an effect ratio/s of > 3. Biosecurity uptake in England was assessed using Official Disease Report Forms (DRFs) from 4074 TB incidents (2018/19). Results: Thirty-three papers with 117 effect estimates met the inclusion criteria and were grouped according to a five-point biosecurity plan. There was consistent evidence for lower TB risk from reducing contact with neighbouring herds and from preventing cattle at higher TB risk entering herds. Evidence for the effectiveness of measures reducing contact between badgers and cattle was inconsistent. The DRF data showed low uptake of biosecurity to reduce contact between badgers and cattle. Limitations: All studies identified were retrospective. Biosecurity was measured using different instruments e.g. questionnaires. Conclusions: There is analytical epidemiological evidence supporting guidance for improving biosecurity, but it has some limitations. Further research is needed to identify the most effective wildlife-focused measures.