DiFLUsion: A novel space-time alert system for HPAI

The emergence and spread of highly pathogenic avian influenza (HPAI) pose significant threats to global poultry industries, wildlife, and public health. Migratory waterfowl play a critical role in its propagation. The current epidemic of HPAI since late 2020 is unprecedented due to a severe increase in incidence, a constant presence without seasonality, greater susceptibility in wild birds, more frequent jumps to wild and domestic mammals (including cats, cows, and mink), and spread to new regions, presenting new challenges in disease control. These changes in the dynamics of the disease have resulted in numerous outbreaks and the death of millions of domestic and wild birds, directly impacting poultry product costs and representing a persistent threat to the poultry industry and public health. In response to this challenge, we present DiFLUsion, an innovative early warning system for HPAI that has been operational in Spain since 2021. DiFLUsion enables early detection in disease-free zones connected by wild bird movements to HPAI-affected areas. This system integrates multiple data sources and analytical tools using Python and ArcGIS, allowing for the modulation of alerts based on the location of HPAI outbreaks in Europe, the seasonality of wild bird movements, and virus survival temperatures. DiFLUsion operates in real-time, updating weekly, sending alerts to the Spanish Ministry of Agriculture, and providing an interactive map viewer. DiFLUsion has effectively identified high-risk areas for HPAI introduction in Spain, aligning with recent outbreak patterns. Over three years, the system generated 77,872 alerts, demonstrating a sensitivity of 85.43% for high-risk categories and a specificity of 74.48% for the highest alert level. These alerts have facilitated preemptive measures, enhancing response times and mitigation strategies. In conclusion, DiFLUsion enhances the decision-making capacity of livestock health managers in Spain, enabling them to prepare for and respond proactively to avian influenza epidemics.