Coronavirus surveillance in passerines reveals novel deltacoronaviruses in Eurasian tree sparrows with implications for One Health and livestock biosecurity

Coronaviruses (CoVs) are widespread RNA viruses infecting a broad range of avian and mammalian hosts. Although gammacoronaviruses and deltacoronaviruses (DCoVs) are common in wild birds, their presence in Eurasian passerines remains poorly understood. We screened 243 birds (35 species) at migratory