BACKGROUND-Antiretroviral chemoprophylaxis before exposure is a promising approach for the prevention of human immunodeficiency virus (HIV) acquisition.

Background The impact of HIV pre-exposure prophylaxis (PrEP) depends on uptake, adherence, and sexual practices. Methods Men and transgender women who have sex with men (MSM/TGW) previously enrolled in PrEP trials were enrolled in a 72 week open label extension (iPrEx OLE). Drug concentrations were measured in plasma and dried blood spots (DBS) in seroconverters and a random sample of seronegatives. Findings 1603 HIV uninfected persons were enrolled, of whom 76% received PrEP. PrEP uptake was higher among those reporting condomless receptive anal intercourse (ncRAI; P=0.003) and having serological evidence of herpes (P=0.03). Among those receiving PrEP, HIV incidence was 1.8/100PY, which was 49% (95% CI: −1 to 74%) lower than among those who concurrently did not choose PrEP after adjusting for sexual behavior, and 53% (95% CI: 26 to 70%) lower than in the placebo arm of the prior randomized phase (3.9/100PY). Among those receiving PrEP, HIV incidence was 4.7/100PY if drug was not detected in DBS, 2.3/100PY if drug concentrations indicated use of less than 2 tablets per week, 0.6/100PY for use of 2 to 3 tablets per week, and 0/100PY for use of 4 or more tablets per week (P<0.0001). PrEP drug concentrations were higher among people with older age, more schooling, ncRAI, more sexual partners, trans-identification, and a history of syphilis or herpes. Interpretation PrEP uptake was high when made available free of charge by experienced providers. PrEP impact is increased by greater uptake and adherence during periods of higher risk; disengagement after initial use is common. DBS drug concentrations are strongly correlated with PrEP’s protective benefit.

HIV-positive persons who do not maintain consistently high levels of adherence to often complex and toxic highly active antiretroviral therapy (HAART) regimens may experience therapeutic failure and deterioration of health status and may develop multidrug-resistant HIV that can be transmitted to uninfected others. The current analysis conceptualizes social and psychological determinants of adherence to HAART among HIV-positive individuals. The authors propose an information-motivation-behavioral skills (IMB) model of HAART adherence that assumes that adherence-related information, motivation, and behavioral skills are fundamental determinants of adherence to HAART. According to the model, adherence-related information and motivation work through adherence-related behavioral skills to affect adherence to HAART. Empirical support for the IMB model of adherence is presented, and its application in adherence-promotion intervention efforts is discussed.

The current work evaluates the HIV Stigma Framework in a sample of 95 people living with HIV recruited from an inner-city clinic in the Bronx, NY. To determine the contributions of each HIV stigma mechanism (internalized, enacted, and anticipated) on indicators of health and well-being, we conducted an interviewer-delivered survey and abstracted data from medical records. Results suggest that internalized stigma associates significantly with indicators of affective (i.e., helplessness regarding, acceptance of, and perceived benefits of HIV) and behavioral (i.e., days in medical care gaps and ARV non-adherence) health and well-being. Enacted and anticipated stigma associate with indicators of physical health and well-being (i.e., CD4 count less than 200 and chronic illness comorbidity respectively). By differentiating between HIV stigma mechanisms, researchers may gain a more nuanced understanding of how HIV stigma impacts health and well-being and better inform targeted interventions to improve specific outcomes among people living with HIV.