  Most epidemic models are spatially aggregate and the index which is most used
for planning and policy numbers, the r number, typically refers to a single
system of interest. Even if r numbers are calculated for each of adjacent
areas, regions or countries for example, there is no interaction between them.
Here we aim to offer a fine-grained geography: models of epidemics in spatially
disaggregated systems with interactions. This offers the possibility of new
insights into the dynamics of epidemics and of policies aimed at mitigation and
control.
