Population size dependent incidence in models for diseases without immunity
- Cite this article as:
- Zhou, J. & Hethcote, H.W. J. Math. Biol. (1994) 32: 809. doi:10.1007/BF00168799
Epidemiological models of SIS type are analyzed to determine the thresholds, equilibria, and stability. The incidence term in these models has a contact rate which depends on the total population size. The demographic structures considered are recruitment-death, generalized logistic, decay and growth. The persistence of the disease combined with disease-related deaths and reduced reproduction of infectives can greatly affect the population dynamics. For example, it can cause the population size to decrease to zero or to a new size below its carrying capacity or it can decrease the exponential growth rate constant of the population.