The horizontal transmission of HIV infection depends primarily on the concentration of virus in the blood and genital secretions. Accordingly, sexual transmission of HIV can be virtually eliminated with successful antiretroviral treatment (ART); not surprisingly, vulnerability for an HIV negative partner exists early in treatment and when/if treatment fails. Treatment of HIV (even at high CD4 count) improves health and prevents neoplasms and tuberculosis. These results have led to widespread recommendation for universal testing and treatment (UTT), limited only by infrastructure and not stage of disease. However, the detection and treatment of acute and early infection remains a challenge. There is strong evidence that treatment of acute and early HIV has both health and public health benefit. And people treated during acute infection have a smaller viral reservoir (“latent pool”) and may be better candidates for attempts at viral eradication (i.e. cure). However, detection of patients with very early infection remains a challenge. Point of care tests currently available to detect acute infection do not perform well. Syndromic algorithms for detection of acute infection are available but they have not been widely used, even in Africa. Use of viral phylogeny to detect HIV clusters has highlighted acute infection in some studies (especially among MSM), but such work has been primarily retrospective; real-time use of viral phylogeny for HIV prevention has not yet been implemented. Ongoing community based “test and treat” trials in Africa may help determine the importance of acute infection in the centre of the pandemic. The outstanding question for public policy is what degree of emphasis to place on detection and treatment of acute and early HIV, a question that can only be addressed with further empirical results and cost/benefit analysis.