  In a recent article Hontelez and colleagues investigate the prospects for
elimination of HIV in South Africa through expanded access to antiretroviral
therapy (ART) using STDSIM, a micro-simulation model. One of the first
published models to suggest that expanded access to ART could lead to the
elimination of HIV, referred to by the authors as the Granich Model, was
developed and implemented by the present author. The notion that expanded
access to ART could lead to the end of the AIDS epidemic gave rise to
considerable interest and debate and remains contentious. In considering this
notion Hontelez et al. start by stripping down STDSIM to a simple model that is
equivalent to the model developed by the present author3 but is a stochastic
event driven model. Hontelez and colleagues then reintroduce levels of
complexity to explore ways in which the model structure affects the results. In
contrast to our earlier conclusions Hontelez and colleagues conclude that
universal voluntary counselling and testing with immediate ART at 90% coverage
should result in the elimination of HIV but would take three times longer than
predicted by the model developed by the present author. Hontelez et al. suggest
that the current scale-up of ART at CD4 cell counts less than 350 cells/microL
will lead to elimination of HIV in 30 years. I disagree with both claims and
believe that their more complex models rely on unwarranted and unsubstantiated
assumptions.
