Mapping global avian influenza risk patterns through waterbird activity entropy

Area of Science:

• Veterinary Epidemiology
• Disease Ecology
• Public Health Surveillance

Background:

• Avian influenza viruses (AIV) represent a significant zoonotic threat with pandemic potential.
• Waterbirds are key reservoirs and vectors for AIV, facilitating spillover events into domestic animals and humans.
• Current surveillance methods may not fully capture the complex dynamics of AIV transmission facilitated by waterbird movements.

Purpose of the Study:

• To introduce and validate waterbird activity entropy (WAE) as a novel indicator for assessing global AIV exposure risk.
• To identify geographical hotspots of potential AIV emergence and transmission.
• To inform and enhance global AIV surveillance strategies.

Main Methods:

• Developed waterbird activity entropy (WAE) using monthly distribution data for 779 waterbird species globally.
• Assessed the explanative power of WAE for predicting global AIV cases, with a focus on H5N1.
• Mapped AIV exposure hotspots and analyzed their overlap with human, cattle, and poultry populations.

Main Results:

• WAE showed high predictive accuracy (AUC = 0.87 ± 0.001) for global AIV cases, particularly H5N1.
• Identified AIV exposure hotspots covering 14% of the global land area.
• Hotspots in the USA, EU, China, and India harbor substantial human and livestock populations, while sub-Saharan Africa presents extensive, under-surveilled hotspot areas.

Conclusions:

• WAE is a valuable tool for identifying AIV exposure hotspots and enhancing global risk assessment.
• The framework provides critical insights into potential AIV emergence by considering waterbird residency and activity.
• Improved surveillance in identified hotspots, especially in under-reported regions like sub-Saharan Africa, is crucial for pandemic preparedness.