Adherence to antiretroviral therapy for the success of emerging interventions to prevent HIV transmission: A wake up call

Despite recent successes in several HIV prevention trials, the epidemic continues to increase in many countries. The most successful biomedical interventions to prevent HIV have been the use of Antiretroviral Therapy (ART) to Prevent Mother-To-Child Transmission (PMTCT), and sexual transmission via microbicides, PreExposure Prophylaxis (PrEP), and treatment of the infected person within discordant couples. In addition medical male circumcision has also been shown to be highly effective in prevention of HIV acquisition. However, emerging data demonstrate that adherence to several of these prevention interventions is critical. ART adherence during and after pregnancy has been shown to be significantly below that recommended for adequate virologic suppression, particularly during the postpartum period. Five recent PrEP trials also demonstrate that the success of PrEP as a public health intervention will necessitate monitoring ART adherence and will include additional interventions to improve or maintain adherence to optimal levels. New successes in HIV prevention research have been tempered by suboptimal adherence. There is a critical need to define practical and effective adherence monitoring strategies as well as controlled trials of adherence interventions in the era of PrEP, Treatment as Prevention (TasP), and PMTCT to maximize their benefit.