| West Nile virus spreads through interacting bird and
mosquito populations, with humans as dead end hosts. The first
recorded epidemic of West Nile virus in North America was in New
York state in 1999, and since then it has spread spatially to most
of the USA, causing over 200 human deaths in 2012. This spatial
spread is modeled by a reaction-diffusion system with cross
infection between birds and mosquitoes. For a simplified version of
the model, the existence of traveling waves is proved and the
spatial spread rate is calculated. Use of a comparison theorem shows
that this may provide an upper bound for the spread rate of the more
complex system. |