  We examine how spatial heterogeneity combines with mobility network structure
to influence vector-borne disease dynamics. Specifically, we consider a
Ross-Macdonald-type disease model on $n$ spatial locations that are coupled by
host movement on a strongly connected, weighted, directed graph. We derive a
closed form approximation to the domain reproduction number using a Laurent
series expansion, and use this approximation to compute sensitivities of the
basic reproduction number to model parameters. To illustrate how these results
can be used to help inform mitigation strategies, as a case study we apply
these results to malaria dynamics in Namibia, using published cell phone data
and estimates for local disease transmission. Our analytical results are
particularly useful for understanding drivers of transmission when mobility
sinks and transmission hot spots do not coincide.
