Abstract
Models of disease transmission in a population with varying densities must assume a relation between infectious contacts and density. Typically, a choice is made between a constant (frequency-dependence) and a linear (density-dependence) contact-density function, but it is becoming increasingly clear that nonlinear functions intermediate between these two extremes are more realistic. It is currently not clear however what the consequences would be of implementing different contact-density functions when population density varies. By combining existing data on Mastomys natalensis demography, density-dependent changes in contacts, and Morogoro virus infection dynamics, we explored the effects of different contact-density function shapes on transmission dynamics and invasion/persistence. While invasion and persistence were clearly affected by the shape of the function, the effects on outbreak characteristics such as prevalence and outbreak size were minor. As a consequence, it would be difficult to distinguish between the different shapes based on how well models fit to real data. This data-driven study confirms that the shape of the transmission-density function must be chosen with care, ideally based on existing information such as a previously quantified contact- or transmission-density relationship or the underlying biology of the host species in relation to the infectious agent.
Important notice This is a pre-print version of the manuscript, made available through bioRxiv.org. Note that this manuscript has not yet been peer-reviewed, and has been submitted to a peer-reviewed journal.