PATHOGEN COEXISTENCE INDUCED BY DENSITY-DEPENDENT HOST MORTALITY

A model of two competing infectious diseases with complete cross-prote ction sharing one host allows for coexistence, provided that the host population is subject to strong density regulation. The phenomenon is caused by the different ways in which host density affects transmissio n rate and transmission period. The analysis suggest that disease coex istence is most likely when the two diseases differ significantly in v irulence and transmission and that the evolutionary stability of the t wo-disease association depends critically on details in the functional relationship between virulence and transmission. (C) 1995 Academic Pr ess Limited