PrEP retention predictors among key populations in urban areas of Zimbabwe - a machine learning approach.

Pre-exposure prophylaxis (PrEP) success depends on adherence and hence retention in care. It is vital to find factors that affect PrEP retention to make this HIV-prevention method successful. The main objectives of this study were to identify the major determinants of PrEP retention at six months from day of initiation and to determine PrEP retention clusters.

On the efficiency of HIV transmission: Insights through discrete time HIV models.

There are different views on which of the two forms of viral spread is more efficient in vivo between cell-free and cell-associated virus. In this study, discrete time human immunodeficiency virus models are formulated and analysed with the goal of determining the form of viral spread that is more efficient in vivo. It is shown that on its own, cell-free viral spread cannot sustain an infection owing to the low infectivity of cell-free virus and cell-associated virus can sustain an infection because of the high infectivity of cell-associated virus.

A comparison of elasticities of viral levels to specific immune response mechanisms in human immunodeficiency virus infection.

Background: The presence of an asymptomatic phase in an HIV infection indicates that the immune system can partially control the infection. Determining the immune mechanisms that contribute significantly to the partial control of the infection enhance the HIV infection intervention strategies and is important in vaccine development. Towards this goal, a discrete time HIV model, which incorporates the life cycle aspects of the virus, the antibody (humoral) response and the cell-mediated immune response is formulated to determine immune system components that are most efficient in controlling viral levels.