Environmental risk factors in the incidence of Johne's disease

Area of Science:

• Veterinary Microbiology and Immunology
• Environmental Science and Public Health

Background:

• Johne's disease (JD), caused by Mycobacterium avium subsp. paratuberculosis (MAP), significantly impacts livestock industries.
• Control is challenging due to sub-clinical infections, persistent MAP shedding, diagnostic limitations, and environmental survival.
• MAP's ability to persist outside the ruminant host is a critical factor in disease spread and management.

Purpose of the Study:

• To review the survival and persistence of MAP outside its ruminant host.
• To assess the role of environmental factors in MAP persistence and spread.
• To identify knowledge gaps and propose inclusive disease management strategies.

Main Methods:

• Review of published literature on risk factor analysis for MAP.
• Assessment of MAP survival in various environmental media and conditions.
• Evaluation of MAP presence and spread in wildlife and its ex-host potential.

Main Results:

• MAP can persist for extended periods in various environmental settings (soils, waters).
• Environmental factors significantly influence MAP survival, persistence, and dispersal.
• Wildlife species may play a role in the dissemination of MAP.

Conclusions:

• Effective JD management requires considering MAP's environmental persistence and transport.
• An inclusive approach encompassing on-farm environmental management, land use, and wildlife dispersal is necessary.
• Integrated strategies are crucial for farms struggling with traditional JD control methods.