Culling and cattle controls influence tuberculosis risk for badgers.

Area of Science:

• Veterinary Epidemiology
• Wildlife Disease Ecology
• Pathogen Transmission Dynamics

Background:

• Bovine tuberculosis (TB) control in cattle is challenging due to persistent infection in wildlife reservoirs.
• European badgers (Meles meles) are a key wildlife host implicated in Mycobacterium bovis transmission to cattle in Britain.
• Previous badger culling policies have yielded variable results in reducing cattle TB incidence.

Purpose of the Study:

• To investigate the impact of repeated badger culling on Mycobacterium bovis prevalence within badger populations.
• To explore the potential for bidirectional transmission of M. bovis between cattle and badgers.
• To inform disease control strategies for multihost pathogens.

Main Methods:

• Analysis of M. bovis infection prevalence in badgers in relation to culling history and landscape features.
• Examination of M. bovis prevalence patterns in badgers during periods of altered cattle TB control measures (e.g., foot and mouth disease epidemic).

Main Results:

• Repeated badger culling in the same areas was associated with increased M. bovis prevalence in badgers, particularly where recolonization by badgers from adjacent areas occurred.
• Suspension of cattle TB controls during a foot and mouth disease epidemic correlated with a widespread increase in M. bovis prevalence in badgers, suggesting cattle-to-badger transmission.
• The observed effects on badger M. bovis prevalence may diminish the benefits of culling for cattle TB control and potentially contribute to negative outcomes.

Conclusions:

• Repeated badger culling can inadvertently increase M. bovis prevalence in badger populations, potentially undermining its efficacy in controlling cattle TB.
• Evidence suggests M. bovis can be transmitted from cattle to badgers, indicating a need to consider both directions of transmission.
• Effective management of multihost pathogens like M. bovis requires comprehensive strategies that account for complex transmission routes and host interactions.