A minimal model coupling communicable and non-communicable diseases

This work presents a model combining the simplest communicable and non-communicable disease models. The latter is, by far, the leading cause of sickness and death in the World, and introduces basal heterogeneity in populations where communicable diseases evolve. The model can be interpreted as a risk-structured model, another way of accounting for population heterogeneity. Our results show that considering the non-communicable disease (in the end, heterogeneous populations) allows the communicable disease to become endemic even if the basic reproduction number is less than $1$. This feature is known as subcritical bifurcation. Furthermore, ignoring the non-communicable disease dynamics results in overestimating the reproduction number and, thus, giving wrong information about the actual number of infected individuals. We calculate sensitivity indices and derive interesting epidemic-control information.Comment: 19 pages, 5 figure

Predator's alternative food sources do not support ecoepidemics with two-strains-diseased prey

An ecoepidemic model is presented, in which two diseases affect the prey. Predators are allowed to have other food sources. Equilibria are analyzed for feasibility and stability. The most striking result is that in these conditions the two strains cannot both survive in the system, contrary to what is possible to obtain, under suitable assumptions, in standard epidemic models