Bayesian phylodynamics of avian influenza A virus H9N2 in Asia with time-dependent predictors of migration
Fig 1
Spatio-temporal distribution of avian-origin H9N2 influenza viruses in Asia between 1976 and 2014.
(a) Spatial distribution where the size of circle represents the number of virus isolates obtained in the affected countries/locations. The value of circle indicates double square roots of virus isolate quantity in each location. Colors in the circle represent different fraction of virus hosts. Most of the isolates originate from chickens and from China. The source of map is http://www.naturalearthdata.com. (b) The number of H9N2 HA isolates that are deposited in NCBI through time. The bars represent the annual number of H9N2 isolates sampled in each region. (c) Inferred effective population sizes of H9N2 in Asia by using Bayesian skyline plot. The effective population size of H9N2 viruses increased in 1996 when more isolates began to be sampled in more countries representing multiple outbreaks.