A review and synthesis of the HIV/AIDS epidemic as a multi-stage process.

As our understanding of the dynamics of the transmission of the HIV virus toward diagnosis of AIDS increases, numerous models are being developed to help explain the underlying mechanism. We show that many of the models established so far in the literature are examples of a general class of multi-stage epidemic models that are themselves right-shift processes as developed in 1969 by Severo. We focus attention on those models that can be described as three-stage, four-stage, five-stage, etc. models.