An AIDS model with distributed incubation and variable infectiousness: applications to i.v. drug users in Latium, Italy.

An AIDS model with distributed incubation and variable infectiousness is considered and simulated via a second-order numerical method. The method is applied to the HIV epidemic among IV drug users in the Latium region of Italy, using available data on the length of the incubation period before the onset of AIDS, on the infectivity of infected individuals during that period, and on the demography of drug users. The contact rate is adjusted to match the actual number of AIDS cases. The sensitivity of the model to uncertainties in the parameters is finally investigated, by performing several simulations.