Abstract

Emerging zoonotic diseases, especially coronaviruses (CoVs), pose significant public health risks, with migratory birds as key reservoirs. This study investigates CoV spillover at the wildlife-domestic interface, focusing on the seasonal and annual fluctuations of avian CoVs in migratory birds at Chongming, China. Samples collected from migratory birds during 2023-2024 showed seasonal variation in CoV prevalence, with Charadriiformes having a 22.29% positivity rate in autumn 2023 and Anseriformes showing 85.71% in winter 2023, decreasing to 10.53% in 2024. Phylogenetic analysis identified Gamma-CoVs as DuCoV_NL3, with high genetic similarity to poultry strains, indicating cross-species transmission. Environmental contamination in wetland habitats facilitated CoV transmission, with migratory birds acting as dispersers. Delta-CoV was detected less frequently but showed diversity in migratory birds and environmental samples. This study provides the first empirical evidence of pathogen spillover from migratory birds to poultry, with environmental contamination playing a key role. The findings emphasize the importance of enhanced surveillance of wildlife-poultry interactions and the need for a One Health approach to prevent zoonotic spillover and mitigate risks.