Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom; andInstitute of Evolutionary Biology, Ashworth Laboratories, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom.
Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom; and.
Proc Natl Acad Sci U S A. 2014 Jul 22;111(29):10767-72. doi: 10.1073/pnas.1401849111. Epub 2014 Jun 23.
Outbreaks of highly pathogenic strains of avian influenza viruses (AIVs) cause considerable economic losses to the poultry industry and also pose a threat to human life. The possibility that one of these strains will evolve to become transmissible between humans, sparking a major influenza pandemic, is a matter of great concern. Most studies so far have focused on assessing these odds from the perspective of the intrinsic mutability of AIV rather than the ecological constraints to invasion faced by the virus population. Here we present an alternative multihost model for the evolution of AIV in which the mode and tempo of mutation play a limited role, with the emergence of strains being determined instead principally by the prevailing profile of population-level immunity. We show that (i) many of the observed differences in influenza virus dynamics among species can be captured by our model by simply varying host lifespan and (ii) increased contact between species of different lifespans can promote the emergence of potentially more virulent strains that were hitherto suppressed in one of the species.
高致病性禽流感病毒（AIV）的爆发给家禽业造成了巨大的经济损失，也对人类生命构成了威胁。这些菌株中有一种可能会进化成能够在人与人之间传播的菌株，引发大流感疫情，这是一个非常令人担忧的问题。到目前为止，大多数研究都集中在从 AIV 的固有可变性的角度来评估这些可能性，而不是从病毒种群面临的生态限制的角度来评估。在这里，我们提出了一个替代的多宿主模型，用于研究 AIV 的进化，在这个模型中，突变的方式和速度所起的作用有限，而是主要由人群免疫水平的流行状况决定菌株的出现。我们表明，（i）通过简单地改变宿主寿命，我们的模型可以捕捉到观察到的流感病毒在物种间的动力学差异中的许多差异，（ii）不同寿命的物种之间接触的增加可以促进潜在更具毒性的菌株的出现，而这些菌株在其中一个物种中受到抑制。
