An application of queuing theory to sis and seis epidemic models

In this work we consider every individual of a population to be a server whose state can be either busy (infected) or idle (susceptible). This server approach allows to consider a general distribution for the duration of the infectious state, instead of being restricted to exponential distributions. In order to achieve this we first derive new approximations to quasistation-ary distribution (QSD) of SIS (Susceptible-Infected-Susceptible) and SEIS (Susceptible-Latent-Infected-Susceptible) stochastic epidemic models. We give an expression that relates the basic reproductive number, R0 and the server utilization, p.