RT Journal Article
SR Electronic
T1 Cross-scale dynamics and the evolutionary emergence of infectious diseases
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 066688
DO 10.1101/066688
A1 Sebastian J. Schreiber
A1 Ruian Ke
A1 Claude Loverdo
A1 Miran Park
A1 Prianna Ahsan
A1 James O. Lloyd-Smith
YR 2020
UL http://biorxiv.org/content/early/2020/04/21/066688.abstract
AB When emerging pathogens encounter new host species for which they are poorly adapted, they must evolve to escape extinction. Pathogens experience selection on traits at multiple scales, including replication rates within host individuals and transmissibility between hosts. We analyze a stochastic model linking pathogen growth and competition within individuals to transmission between individuals. Our analysis reveals a new factor, the cross-scale reproductive number of a mutant virion, that quantifies how quickly mutant strains increase in frequency when they initially appear in the infected host population. This cross-scale reproductive number combines with viral mutation rates, single-strain reproductive numbers, and transmission bottleneck width to determine the likelihood of evolutionary emergence, and whether evolution occurs swiftly or gradually within chains of transmission. We find that wider transmission bottlenecks facilitate emergence of pathogens with short-term infections, but hinder emergence of pathogens exhibiting cross-scale selective conflict and long-term infections. Our results provide a framework to advance the integration of laboratory, clinical and field data in the context of evolutionary theory, laying the foundation for a new generation of evidence-based risk assessment of emergence threats.Competing Interest StatementThe authors have declared no competing interest.