APP and infection: Based on our results and the pathogen characteristics, we assume that, in Serbia, APP transmission occurs and is maintained within wild boar populations by direct contact or aerosol transmission and suggest that the wild boars present a reservoir of infection for free-ranging backyard pigs, usually reared in Eastern Serbia and the Vojvodina province (Prodanov-Radulovic et al. 2015; Neskovic et al. 2021).