Spillover and pandemic properties of zoonotic viruses with high host plasticity

TLDR

Most human infectious diseases originate from animals, and understanding the epidemiologic circumstances of zoonotic spillover, amplification, and spread is essential for prioritizing surveillance and predicting future emergence risk. The study examines animal hosts and transmission mechanisms involved in zoonotic virus spillover to identify factors influencing spillover dynamics. Viruses with high host plasticity are more likely to amplify spillover through secondary human‑to‑human transmission, spread more widely, and arise from practices mixing diverse animal species, indicating higher pandemic potential.

Abstract

Abstract Most human infectious diseases, especially recently emerging pathogens, originate from animals and ongoing disease transmission from animals to people presents a significant global health burden. Recognition of the epidemiologic circumstances involved in zoonotic spillover, amplification and spread of diseases is essential for prioritizing surveillance and predicting future disease emergence risk. We examine the animal hosts and transmission mechanisms involved in spillover of zoonotic viruses to date and discover that viruses with high host plasticity (i.e. taxonomically and ecologically diverse host range) were more likely to amplify viral spillover by secondary human-to-human transmission and have broader geographic spread. Viruses transmitted to humans during practices that facilitate mixing of diverse animal species had significantly higher host plasticity. Our findings suggest that animal-to-human spillover of new viruses that are capable of infecting diverse host species signal emerging disease events with higher pandemic potential in that these viruses are more likely to amplify by human-to-human transmission with spread on a global scale.