A new and potentially important prevention strategy for HIV infection is “test and treat”, in which positive testing is followed by treatment (Montaner, et al. Lancet. 2006;368:531-6). HIV testing can reduce new infections as individuals aware of their HIV status can reduce their risk behavior (Marks, et al. AIDS. 2006;20:1447-50). Treatment of infected individuals can prevent new infections as antiretroviral drugs suppress the viral load, which is the key factor driving transmission of HIV (Quinn, et al. N Engl J Med. 2000;342:921-9). Granich, et al. explored this “test and treat” approach in a key mathematical modeling study (Granich, et al. Lancet. 2009;373:48-57). Most importantly, they predicted that annual voluntary HIV testing followed by immediate start of antiretroviral drugs for those individuals who test positive regardless of their CD4 count, could reduce the HIV pandemic to one incident case of HIV per 1,000 people within a decade. However, the mathematical model made several assumptions which may not be practical in a clinical setting. These challenges are outlined below.