Department of Advanced Transdisciplinary Science, Hokkaido University, Sapporo, Hokkaido, Japan.
Laboratory of RNA Viruses, Department of Virus Research, Institute for Life and Medical Sciences (LiMe), Kyoto University, Kyoto, Japan.
PLoS Comput Biol. 2023 May 30;19(5):e1011173. doi: 10.1371/journal.pcbi.1011173. eCollection 2023 May.
Viruses evolve in infected host populations, and host population dynamics affect viral evolution. RNA viruses with a short duration of infection and a high peak viral load, such as SARS-CoV-2, are maintained in human populations. By contrast, RNA viruses characterized by a long infection duration and a low peak viral load (e.g., borna disease virus) can be maintained in nonhuman populations, and the process of the evolution of persistent viruses has rarely been explored. Here, using a multi-level modeling approach including both individual-level virus infection dynamics and population-scale transmission, we consider virus evolution based on the host environment, specifically, the effect of the contact history of infected hosts. We found that, with a highly dense contact history, viruses with a high virus production rate but low accuracy are likely to be optimal, resulting in a short infectious period with a high peak viral load. In contrast, with a low-density contact history, viral evolution is toward low virus production but high accuracy, resulting in long infection durations with low peak viral load. Our study sheds light on the origin of persistent viruses and why acute viral infections but not persistent virus infection tends to prevail in human society.
病毒在感染宿主的种群中进化，宿主种群动态影响病毒的进化。感染持续时间短、病毒载量高的 RNA 病毒，如 SARS-CoV-2，在人群中得以维持。相比之下，感染持续时间长、病毒载量低的 RNA 病毒（如博尔纳病病毒）可以在非人类种群中维持，而持续存在病毒的进化过程很少被探索。在这里，我们使用一种包括个体水平病毒感染动力学和种群规模传播的多层次建模方法，根据宿主环境（特别是感染宿主接触史的影响）考虑病毒进化。我们发现，在高度密集的接触史中，高病毒产生率但低准确性的病毒可能是最佳选择，导致具有高病毒载量峰值的短传染期。相比之下，在低密度接触史中，病毒进化倾向于低病毒产量但高准确性，导致具有低病毒载量峰值的长感染期。我们的研究揭示了持久性病毒的起源，以及为什么急性病毒感染而不是持续性病毒感染往往在人类社会中占主导地位。
