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

Clinical trial data have shown that oral pre-exposure prophylaxis (PrEP) is efficacious when taken as prescribed; however, PrEP adherence is complex and must be understood within the context of variable risk for HIV infection and use of other HIV prevention methods. Different levels of adherence may be needed in different populations to achieve HIV prevention, and the optimal methods for achieving the necessary adherence for both individual and public health benefits are unknown. Guidance for PrEP use must consider these questions to determine the success of PrEP-based HIV prevention programs. In this article, we propose a new paradigm for understanding and measuring PrEP adherence, termed prevention-effective adherence, which incorporates dynamic HIV acquisition risk behaviors and the use of HIV alternative prevention strategies. We discuss the need for daily PrEP use only during periods of risk for HIV exposure, describe key issues for measuring and understanding relevant behaviors, review lessons from another health prevention field (i.e., family planning), and provide guidance for prevention-effective PrEP use. Moreover, we challenge emerging calls for sustained, near perfect PrEP adherence regardless of risk exposure and offer a more practical and public health-focused vision for this prevention intervention.

HIV continued to spread among MSM in Lima even when a decline in bacterial STIs and increase in condom use were estimated to occur. Intensification of medical and behavior prevention interventions is warranted for MSM in Peru.

In 2008, the Pre-exposure Prophylaxis Initiative (iPrEx) study expanded to include men who have sex with men (MSM) in Chiang Mai, Thailand. In full, 114 participants from Chiang Mai joined this international double-blinded trial of daily FTC-TDF (Truvada®) or placebo as a pre-exposure prophylaxis (PrEP) HIV prevention strategy. To better understand the characteristics of iPrEx participants specifically from this underserved population in Thailand, and gain insights into their experiences of trying to take a daily tablet as part of this blinded PrEP trial, we conducted a qualitative study. In 2010, 32 MSM iPrEx participants provided in-depth interviews and an additional 14 joined focus group discussions. Results of the qualitative analyzes suggested that participants held generally positive attitudes toward the iPrEx study and study medication and related this to high rates of adherence to the daily regimen. Participants also reflected on the provision of quality health care as part of participation in the trial, as well as support from clinical research staff, family and friends as helpful in supporting high rates of study medication adherence. Discourse concerning challenges to adherence included medication taking behavior, which was contextualized by lifestyle, living arrangement, social life, social stigma in terms of being mistakenly identified as HIV positive or unintentional disclosure of sexual identity to family and friends, and relationship conflicts with partners. The results provide broader perspectives of participant experiences of the study medication and daily adherence in the larger contexts of the MSM community, close relationships, and the study climate, and can be leveraged in constructing PrEP adherence support approaches within these communities.

In 2010, the iPrEx study demonstrated efficacy of daily emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) pre-exposure prophylaxis (PrEP) in reducing HIV acquisition among men who have sex with men. Adherence to study product was critical for PrEP efficacy, and varied considerably, with FTC/TDF detection rates highest in the United States. We conducted a qualitative study to gain insights into the experiences of iPrEx participants in San Francisco (SF) where there was high confirmed adherence, to understand individual and contextual factors influencing study product use in this community. In 2009 and 2011, we conducted focus groups and in-depth interviews in 36 and 16 SF iPrEx participants, respectively. Qualitative analyses indicate that participants joined the study out of altruism. They had a clear understanding of study product use, and pill taking was facilitated by establishing or building on an existing routine. Participants valued healthcare provided by the study and relationships with staff, whom they perceived as nonjudgmental, and found client-centered counseling to be an important part of the PrEP package. This facilitated pill taking and accurate reporting of missed doses. Adherence barriers included changes in routine, side effects/intercurrent illnesses, and stress. Future PrEP adherence interventions should leverage existing routines and establish client-centered relationships/ environments to support pill taking and promote accurate reporting.

Among MSM in Peru, HIV and syphilis prevalence and HIV incidence were high, especially among cross-dressers. The high prevalence of bisexuality and low rates of consistent condom use, especially with female sexual partners indicates potential HIV transmission into the heterosexual population.

Background Pre-exposure prophylaxis (PrEP) has been proven to reduce HIV acquisition in men who have sex with men and transgender women (MSM/TGW). For maximal impact, PrEP should be targeted to subpopulations accounting for the largest proportion of infections (population attributable fraction, PAF) and for whom the number needed to treat (NNT) to prevent infection is lowest. Methods The iPrEx study was a randomized controlled efficacy trial of tenofovir-disoproxil-fumarate/emtricitabine PrEP in 2499 MSM/TGW on 4 continents. We calculated the association between demographic and risk behavior during screening with subsequent seroconversion among placebo recipients using a Poisson model, and the PAF and NNT for risk behavior subgroups. Findings Of 1248 placebo participants enrolled, 83 became HIV infected in follow-up. Participants reporting non-condom receptive anal intercourse (ncRAI) seroconverted significantly more often than MSM/TGW reporting no condomless anal sex (adjusted hazard ratio (AHR) 5·11, 95% CI 1·55-16·79). The overall PAF for MSM/TGW reporting ncRAI was 64% (prevalence=60%). Most of this risk came from ncRAI with unknown serostatus partners (PAF 53%, prevalence=54%, AHR 4·76); in contrast, the PAF for ncRAI with an HIV positive partner, an uncommon practice, was only 1% (prevalence 1%, AHR=7·11). The overall NNT per year for the cohort was 62 (95% CI 44-147). NNTs were lower for MSM/TGW self-reporting ncRAI, cocaine use, or a sexually transmitted infection (NNT= 36, 12, and 41 respectively). Having a single partner or non-condom insertive anal sex had the highest NNTs. Interpretation PrEP may be most effective at a population level if targeted toward MSM/TGW reporting ncRAI, even with partners perceived to be HIV negative. Substance use history and testing for STIs may also inform individual decisions to start PrEP. Considering PAF and NNT can aid in discussing the benefits and risks of PrEP with MSM/TGW. Funding Funded by the National Institute of Allergy and Infectious Diseases and the Bill and Melinda Gates Foundation; ClinicalTrials.gov number NCT00458393.

The recent successes of biomedical HIV prevention approaches have sparked considerable debate over the scalability, feasibility, and acceptability of pre-exposure prophylaxis (PrEP) as a widespread prevention strategy for men who have sex with men and trans-gender. Anticipated difficulties with PrEP adherence and concerns about resources required to best support it have tempered enthusiasm of PrEP demonstration projects and roll-out. While no evidence-based approach for supporting PrEP use is presently available, a number of approaches have been developed in the context of double-blind, randomized, placebo-controlled trials of PrEP that can provide guidance in moving forward with real world support of open label PrEP use. We present the development, implementation and evaluation of feasibility and acceptability of next-step counseling (NSC) and neutral assessment (NA), the adherence support and promotion of accurate reporting approaches used in the late phases of the iPrEx study. Evaluation of the approach from the perspective of implementers of over 15,000 NSC sessions in seven different countries with almost 2,000 iPrEx participants provided support for NSC, its brevity (averaging ~14 min per follow-up session) and overall acceptability and feasibility. NA also was generally well supported, with a majority of study staff believing this approach was feasible and acceptable; however, lower acceptability for certain aspects of NA was noted amongst staff reporting NA was different from their previous interview approach. Quantitative and qualitative data gathered from implementers were used to make modifications for supporting PrEP use in the open-label extension of iPrEx.