Healthy pangolin virome reveals mammalian viral diversity and zoonotic risk

Pangolins, the world's most trafficked mammals, have emerged as critical subjects of study due to their potential role as intermediate hosts for zoonotic viruses. While previous studies have primarily focused on diseased pangolins, the virome composition of healthy individuals remains largely unexplored.

To address this knowledge gap, we performed comprehensive metatranscriptomic analysis of 83 healthy pangolins, in comparison with virome data of 52 diseased individuals derived from previously published datasets. We identified 51 viral operational taxonomic units (vOTUs) across six mammalian-associated viral families: Parvoviridae, Picornaviridae, Papillomaviridae, Circoviridae, Flaviviridae, and Paramyxoviridae. Notably, we observed recombination in Morbillivirus canis isolate BJ16B35, Canine distemper virus strain PS, and UN_MBA191024-Paramyxoviridae-1 from pangolins and domestic dogs, suggesting cross-species transmission dynamics. Co-infection analysis revealed a strong positive correlation between Copiparvovirus P171T/pangolin/2018 and Pangolin protoparvovirus, suggesting possible shared transmission pathways. Several viruses, including Orthopneumovirus hominis and Orthorubulavirus mammalis, were exclusively detected in diseased pangolins, implicating their potential role in pathogenesis. Zoonotic risk assessment identified 16 vOTUs with high predicted potential for human infection, including Pangolin pestivirus and Manis javanica papillomavirus 1.

Our findings significantly expand our understanding of viral diversity in healthy pangolins and help distinguish commensal viral communities from potentially pathogenic ones. This research underscores the importance of continued wildlife viral surveillance for both conservation and public health preparedness. Video Abstract.