Bridge hosts, a missing link for disease ecology in multi-host systems

Area of Science:

• Ecology
• Epidemiology
• Disease Ecology

Background:

• Ecological functional groups simplify complexity, but epidemiological host roles need clearer definitions.
• Existing definitions of host roles in epidemiology are often vague, lacking clarity on function-role relationships.

Purpose of the Study:

• To define "bridge hosts" and elucidate their epidemiological consequences.
• To establish an operational framework for identifying bridge hosts by integrating ecological and epidemiological approaches.

Main Methods:

• Defining bridge hosts based on pathogen competence and contact with both maintenance and target populations.
• Illustrating the framework with Avian Influenza Virus transmission at wild bird/poultry interfaces in Africa.
• Analyzing other multi-host systems to demonstrate the definition's utility.

Main Results:

• Bridge hosts act as critical links for pathogen transmission between distinct host populations.
• The proposed framework effectively integrates ecological and epidemiological data to identify bridge hosts.
• The definition is applicable to various multi-host systems, including those at wildlife/domestic/human interfaces.

Conclusions:

• Clear definitions of bridge hosts are essential for understanding and managing infectious diseases in complex ecological systems.
• Bridge hosts play a significant role in the dynamics of emerging infectious diseases at human-wildlife interfaces.
• The ecological and epidemiological framework presented aids in disease management strategies.