Ricerc@Sapienza

In this project the problem of HIV/AIDS diffusion is faced ; a new model recently proposed is considered. It assumes two classes of susceptible subjects: the ones with wise behaviours and the one that by incautious acts could contract the virus. The infected subjects are divided into three classes: the ones not aware of their status (and therefore could infect other subjects), the patients in the pre-aids status and the aids patients. The HIV/AIDS spread has two main particularities . The first one is that with wise behavior its diffusion could be drastically reduced. The second particularity is that there is a period, more or less long (up to 10 years), in which the symptoms of the disease are not evident; therefore, among infected subjects the most dangerous are those (up to 54% of the entire infected population) that, not aware of their status, could infect the unwise susceptible subjects. Currently no vaccine exists and the treatment consists in standard antiretroviral therapy . This model allows to propose suitable control actions according to the indications of the World Health Organization: 1) a control designed for healthy people (information campaign); 2) a control devoted to a fast identification of new infections (test campaign); 3) medication to the aware infected subjects.
The costs of prevention 1 and 2 represent an immediate economic effort, whereas their effects could be noted only in the future. Therefore, a schedule of the control action is advisable. This project aims at determining the optimal resources allocation both in presence of full information and in the realistic case when only partial data are available. The introduction of control actions could be performed taking into account the problem of resource limitations, both from the economic point of view and the logistic one. It could be faced, introducing a suitable cost index. The problem of not complete information could be addressed by using an observator.