Pathogen Exposure in Cattle at the Livestock-Wildlife Interface

Area of Science:

• Veterinary Epidemiology
• Wildlife-Livestock Interactions
• Infectious Disease Ecology

Background:

• Land use significantly influences human infectious disease risk.
• Understanding land use effects on livestock disease risk is crucial for animal health and food security.
• Limited research exists on how diverse land management practices impact livestock pathogen exposure.

Purpose of the Study:

• To investigate the association between land use patterns and pathogen exposure in cattle.
• To compare disease risk in cattle across private ranches (low-medium intensity, high wildlife) and group ranches (high intensity, low wildlife) in Kenya.
• To identify how different ranching systems and wildlife densities affect exposure to specific livestock pathogens.

Main Methods:

• Surveyed cattle on six ranches in rural Kenya representing two distinct ranching systems.
• Tested cattle for exposure to three key pathogens: Brucella spp., bovine viral diarrhea virus (BVDV), and Leptospira serovar Hardjo.
• Analyzed pathogen exposure patterns in relation to ranch type, cattle production intensity, and wildlife densities.

Main Results:

• Leptospira serovar Hardjo exposure risk was significantly higher on private ranches compared to group ranches.
• No significant difference in exposure risk was observed for Brucella spp. or BVDV between the two ranch types.
• Pathogen-specific differences in exposure risk suggest varying transmission modes and influences of land use and wildlife contact.

Conclusions:

• Wildlife-livestock contact patterns appear to be a key factor in shaping pathogen transmission dynamics in livestock.
• The impact of land use on livestock disease risk is pathogen-dependent, influenced by factors like transmission routes and host-pathogen interactions.
• Ranching systems with higher wildlife densities may present increased risk for specific zoonotic and livestock diseases like Leptospirosis.