| Pathogenesis of HIV-1 and HIV-2 infection has been shown to be strikingly different both with respect to CD4+ T-cell decline and time to AIDS and death. The existence of a significant group of HIV-2 infected non-progressors has been speculated. Studies on HIV-2 progression have mainly been based on data from seroprevalent individuals, who entered the cohort study after HIV infection. Time from cohort entry until AIDS or death is the principal time variable. If data on a marker of disease progression has been collected, Markov models can be used to describe progression through the marker based stages. Individuals are in follow-up during different stages of disease progression, and all this information can be combined to describe the overall natural history from seroconversion to until AIDS or death. The aim of the current project is to use a CD4+ staged Markov model to compare progression of HIV-1 and HIV-2 infection, using data from a cohort study from The Gambia. The proportion of HIV-2 infected individuals without AIDS progression is estimated, as well as the effect of age and sex on progression rate. |
