Infection thresholds for two interacting pathogens in a wild animal population

Area of Science:

• Epidemiology
• Disease Ecology
• Mathematical Biology

Background:

• Understanding pathogen dynamics is crucial for wildlife health and conservation.
• Interactions between pathogen variants can significantly alter disease spread and impact.
• Wild animal populations face complex infectious disease challenges.

Purpose of the Study:

• To model the dynamics of two interacting pathogen variants within a wild animal host population.
• To define invasion thresholds for competing pathogen variants using mathematical approaches.
• To identify specific criteria for various interaction outcomes between pathogen variants.

Main Methods:

• Utilized the next-generation matrix approach to analyze pathogen variant dynamics.
• Defined invasion criteria for a new variant when a resident variant is established.
• Developed explicit conditions for different interaction scenarios.

Main Results:

• Established criteria for competitive exclusion between pathogen variants.
• Identified conditions where one variant dominates or is eliminated.
• Characterized scenarios of independent population dynamics regardless of infection order.
• Defined conditions for synergistic or antagonistic interactions, including transmission enhancement.

Conclusions:

• The model provides a framework for predicting pathogen variant interactions in wildlife.
• Understanding these dynamics is key to managing disease outbreaks in animal populations.
• The criteria offer insights into factors driving pathogen evolution and persistence.