11/2

It was interesting to see these authors try to take what is clearly a complex, multifaceted and amorphous issue and try to quantify it concretely in a mathematical model, Yet ironically, this attempt at pinning down the transmission of HIV merely served, in my opinion, to highlight the many variables that make dealing with the HIV epidemic such a Herculean task. The R0 value of the rate of transmission of the disease obviously varies greatly according to age, sex, and region (and therefore what usual method of transmission is most prevalent). The increased life expectancy resulting from ARV treatment, normally seen as a positive thing, is here in the 'pessimistic model' seen as merely a further mechanism of disease spread, since the prevalence of the disease is not decreasing due to death. This illustrates the importance of multi-pronged approach in dealing with the AIDS epidemic. ARV treatment alone is clearly not sufficient to reduce incidence of HIV (particularly as ARV's effectiveness decreases and toxicity increases over time)-- behavioral changes must occur as well. Prevention must be emphasized as much, if not more so, than treatment, whether that means preventative medications, behavior change, STD treatment or circumcision.