Andreas Handel

• 
  Flu in ducks and water - a multiscale modeling study
  Andreas Handel

  It has recently been suggested that for avian influenza viruses, prolonged persistence in the environment plays an important role in the transmission between birds. In such situations, influenza virus strains may face a trade-off: They need to persist well in the environment at low temperatures, but they also need to do well inside an infected bird at higher temperatures. Here, we report an analysis of fitness for avian influenza A viruses across scales, focusing on the phenotype of viral persistence. Taking advantage of a unique dataset that not only reports environmental virus persistence, but also strain-specific viral kinetics from duck challenge experiments, we show that the environmental persistence phenotype of a strain does not impact within-host infection dynamics and virus load. We thereby establish that for this phenotype, the scales of within-host infection dynamics and between-host environmental persistence do not interact: the virus can optimize fitness on each scale without cross-scale trade-offs. Instead, we confirm the existence of a temperature-dependent persistence trade-off on a single scale, with some strains optimizing environmental persistence in water at low temperatures while others reduce sensitivity to increasing temperatures.