Opportunity Drives Spillover: Serological Surveillance across Carnivores, Omnivores and Herbivores in an HPAIV H5 Hotspot in North-East Germany, 2023–2025

In North-East Germany’s offshore islands and mainland coast, wild ruminants, boar, and carnivores were tested for H5-HPAI antibodies. Wild ruminants were seronegative; 3.5% of boar and 12.5–21.9% of carnivores were seropositive, evidencing frequent spillover. Because such events may accelerate mammalian—and ultimately human—adaptation, sustained One- Health monitoring is essential. Summary Across offshore islands and the mainland coast of North-East Germany, H5 HPAI serosurveillance in wildlife found no seroconversion in ruminants, but positives in 3.5% of boar and 12.5–21.9% of carnivores, indicating ongoing spillover and risk of avian-to- mammalian adaptation.