Highly pathogenic avian influenza A(H5N1) has expanded geographically and ecologically, affecting wild birds, mammalian wildlife, domestic animals, and humans. Wildlife surveillance provides critical early warning for One Health preparedness, yet national-scale analyses integrating host ecology, spatial patterns, seasonality, viral lineage, and risk factors remain limited. This study analysed Canadian wildlife HPAI A(H5N1) surveillance records from 2022 to 2026 to characterise spatiotemporal dynamics and identify factors associated with detection counts. A retrospective analysis of 2,657 detections across 13 provinces and territories was conducted using descriptive epidemiology, spatial clustering methods, and Negative Binomial mixed models. Detections were predominantly avian, with waterfowl and raptors as the major host groups, while mammals accounted for a smaller but epidemiologically important proportion. Detection burden was highest in 2022, with increased activity in autumn and spring. Ontario, Alberta, and British Columbia were identified as major hotspots, with evidence of local clustering in parts of the Prairie region. Reassortant Eurasian-North American lineages dominated detections and were strongly associated with higher detection counts. Modelling results identified year, season, and lineage as key predictors. These findings support risk-based One Health surveillance prioritising high-burden regions, migration-associated periods, key avian host groups, reassortant viral lineages, and continued monitoring of mammalian wildlife.

翻译：高致病性禽流感A(H5N1)已在地理与生态层面持续扩展，影响野生鸟类、哺乳动物、家养动物及人类。野生动物监测为“全健康”防控体系的早期预警提供了关键支撑，然而在国家级尺度上整合宿主生态、空间格局、季节特征、病毒谱系及风险因素的系统性分析仍十分有限。本研究对2022至2026年加拿大野生动物的高致病性A(H5N1)禽流感监测记录进行了分析，以阐明其时空动态并识别与检出数量相关的关键因素。采用描述性流行病学、空间聚类方法及负二项混合模型，对涵盖13个省和地区的2657次检出记录开展了回顾性分析。检出样本以鸟类为主，水禽与猛禽为主要宿主类群，而哺乳动物虽占比较小却具有重要流行病学意义。检出数量峰值出现在2022年，秋季与春季呈现活跃态势。安大略省、阿尔伯塔省和不列颠哥伦比亚省被识别为主要热点区域，草原地区的局部聚类特征亦有显现。欧亚-北美重组谱系在检出中占主导地位，并与较高的检出数量显著相关。建模结果表明，年份、季节及病毒谱系为关键预测因子。上述发现支持基于风险的“全健康”监测策略，即优先关注高负担区域、迁徙相关时段、主要鸟类宿主类群、重组病毒谱系，并持续加强对哺乳动物的监测。