Current HIV Research - Volume 11, Issue 7, 2013

The aim of this study was to describe some characteristics of vaginal, anal and oral sexual behavior in Spanish adolescents. It was a cross-sectional descriptive population study conducted using a probabilistic sample survey. The sample was composed of 4,612 male and female adolescents, of whom 1,686 reported having penetrative sexual experience. Sample size was established with a 97% confidence level and a 3% estimation error. Data collection took place in secondary education schools. Mean age of vaginal sex initiation was 15 years. Compared to females, males reported an earlier age of anal and oral sex initiation and a larger number of vaginal and anal sexual partners. Males also reported a higher frequency of penetrative sexual relations under the influence of alcohol or other drugs. A higher percentage of females than males reported not using a condom in their first anal sexual experience. This study provides a current overview of the sexual behavior of adolescents that can be useful for the design of future programs aimed at preventing HIV and sexually transmitted infections (STIs).

Pre-exposure prophylaxis (PrEP) has the potential to help reduce new HIV infections among young men who have sex with men (YMSM). Using a cross-sectional survey of YMSM (N=1,507; ages 18-24), we gauged YMSM’s PrEP awareness and PrEP-related beliefs regarding side effects, accessibility, and affordability. Overall, 27% of the sample had heard about PrEP; 1% reported ever using PrEP prior to sex. In a multivariate logistic regression, we found that YMSM were more likely to have heard about PrEP if they were older, more educated, were residentially unstable in the prior 30 days, had insurance, or reported having at least one sexually transmitted infection in their lifetime. We found no differences by race/ethnicity, history of incarceration, or recent sexual risk behavior. In multivariate linear regression models, Black and Latino YMSM were more likely than Whites to state they would not use PrEP because of side effect concerns. YMSM were more likely to indicate that they would not be able to afford PrEP if they did not have insurance or if they had a prior sexually transmitted infection, PrEP rollout may be hindered due to lack of awareness, as well as perceived barriers regarding its use. We propose strategies to maximize equity in PrEP awareness and access if it is to be scaled up among YMSM.

This paper provides a critical narrative review of the scientific literature on intimate partner violence (IPV) and risky sexual behavior as well as sexually transmitted infections (STIs) among adolescents, aged 14-24 years. Intimate partner violence has been associated with a number of high risk sexual behavior, including inconsistent condom use, multiple sexual partners, earlier sexual debut, consuming substances while engaging in sexual behavior, and sexually transmitted infections among adolescents. An electronic search of the literature was performed using PubMed/MEDLINE, PsycINFO, and Web of Science and articles from January 2000 - June 2013 were reviewed. Search terms included a combination of keywords for IPV, HIV/STI risk, and adolescents. The findings from the review indicated that IPV was associated with inconsistent condom use, STIs, early sexual debut, multiple sexual partners, and other HIV/STI-associated risk factors among adolescents. HIV/STI interventions for female adolescents often focus on increasing behavioral and cognitive skills, specifically condom negotiation. However, within the context of an abusive relationship, it becomes challenging for adolescents to enact these skills, where this behavior could potentially place them at greater risk. Components that address violence are necessary within HIV prevention programming. Additionally, integration of IPV screening within healthcare settings is important along with a combined approach that merges resources from healthcare, social, and community-level settings.

The aim of this study was to determine whether there are differences in power distribution between males and females in couple relationships, and whether these differences are associated with risky sexual behaviour in a representative sample of Spanish adolescents. The study also examined the influence of partner's age on the power dynamics that occur in a relationship. The sample comprised 1,223 adolescents attending state and private schools in the 17 autonomous regions in Spain. All adolescents included in the sample were involved in a heterosexual relationship (for at least one month) at the time of evaluation. Relationship control and decision-making dominance were evaluated using the Spanish version of the Sexual Relationship Power Scale. Two further questionnaires were administered to collect sociodemographic data, and data on sexual behaviour. Females showed greater relationship control and greater control over decision-making than males. In the female group, participants with partners five or more years older than them were found to have less control over decision-making, while greater control over decision-making was linked to less exposure to risk. In the male group, participants with partners older than them were found to have greater control over decisionmaking, while relationship control was found to be negatively related to exposure to sexual risk. These results highlight the importance of taking power distribution and gender inequalities in couple relationships into consideration for STI and HIV prevention.

We examine potential use of pre-exposure prophylaxis (PrEP) among young adult women, based on nationally representative random-digit dial telephone household survey of 1,453 US African-American and white women. The hypotheses were generated based on Health Belief Model. Our analyses showed that, as compared to women of 30-45 years old, young women of 20-29 years old experienced stronger social influences on PrEP uptake. However, as compared to older women, young women did not report higher potential PrEP uptake or adherence, despite their greater risk of HIV. For PrEP to be an effective method of prevention for young adult women, interventions are needed to increase HIV risk awareness.

Objectives: To examine the efficacy of sexual risk reduction interventions among South African youth. Methods: Electronic databases were searched to identify studies published between 2007 and early 2013. Studies were eligible if they (1) targeted youth age 9-26, (2) evaluated sexual risk reduction interventions and (3) reported at least one behavioral outcome. Independent raters coded study characteristics, and intervention content. Weighted mean effect sizes were calculated; positive effect sizes indicated less sexual risk behavior and incident STIs. Results: Ten studies (k = 11; N = 22,788; 54% female; 79% Black-African) were included. Compared to controls, interventions were successful at delaying sexual intercourse and, among sexually active youth, at increasing condom use. A single study found reductions in the incidence of herpes simplex virus-2, but not HIV. Conclusions: Implementing behavioral interventions to delay sexual debut and improve condom use can help to reduce the transmission of HIV among South African youth.

Adolescent girls throughout the globe are particularly vulnerable to HIV infection. In the U.S., sexually-active, adolescent girls in urban settings are at elevated risk for HIV. The purpose of this study was to describe a theoreticallydriven, HIV prevention intervention tailored for adolescent girls and evaluate its effectiveness in reducing sexually-risky behaviors. Sexually-active urban adolescent girls (n=738) recruited in a mid-size, northeastern U.S. city were recruited for a randomized controlled trial and participated in a theory-based, sexual risk reduction intervention or a structurallyequivalent health promotion control group. Preferred sexual risk-reduction strategies were collected using ACASI at baseline, then at 3, 6 and 12-months post-intervention. The manualized interventions included four small group sessions and two booster sessions all of which included information, motivational and behavioral skill constructs. Facilitators were trained in motivational interviewing and incorporated this technique throughout the sessions. Relative to girls in the control group, girls receiving the sexual risk-reduction intervention were more likely to increase the number of sexual-risk reduction strategies at post-intervention; however, girls in the control group also increased the number of strategies used though not at the same rate. Theory-based, HIV interventions tailored to adolescent girls can help increase sexual riskreduction behaviors and provide girls with a menu of options to employ. Due to the manualized structure of this randomized controlled trial, the intervention could be modified to meet the needs of adolescent girls throughout the world. Trial Registration: This study is registered at ClinicalTrials.gov (NCT 00161343).

Objectives: Increasing life expectancy of HIV-1–infected patients raises interest in how trial results apply to older patients. This post-hoc analysis evaluated potential differences in efficacy and safety in older (≥50 years) versus younger (<50 years) patients in the ECHO and THRIVE trials over 96 weeks. Methods: HIV-infected, treatment-naïve adults were randomized to receive rilpivirine (RPV) or efavirenz (EFV), plus a background regimen. Virologic response rates (FDA snapshot analysis; HIV-1 RNA <50 copies/mL) were assessed at Week 96. Total-body bone mineral density was evaluated at baseline and Week 96 by dual-energy X-ray absorptiometry scans. Serum concentrations of 25-hydroxy vitamin D (ECHO trial only) were also measured at baseline, Week 24 and Week 48. Results: 1368 patients were treated. At Week 96, virologic response rates were similar between older (77%) and younger (76%) RPV-treated patients and numerically higher in older (84%) versus younger (76%) EFV-treated patients. No clinically relevant age-related differences were observed in immunologic responses. Small differences were noted in older versus younger patients in adverse events (higher rates of depression, insomnia, and rash in older EFV-treated patients), laboratory abnormalities (increased low-density lipoprotein cholesterol and hyperglycemia in older EFV-treated patients and increased amylase in older patients across treatments), bone mineral density (larger decreases in older patients across treatments), and progression to severe vitamin D deficiency (greater in older versus younger EFV-treated patients). Conclusion: Efficacy and safety outcomes were generally similar in older versus younger patients in the ECHO and THRIVE trials.

Although the development of a protective vaccine remains the most effective strategy for the global control of HIV/AIDS, another practical form of medical intervention would be a microbicide capable of preventing HIV-1 transmission at the mucosal level. A broad spectrum of antiviral molecules have demonstrated in vitro efficacy in proofof- principle studies, and a selected few have already been tested in pre-clinical and clinical microbicide trials. Nevertheless, major hurdles remain to be overcome and there is still much uncertainty about the choice of inhibitors, formulations and administration vehicles for obtaining a safe and effective microbicide. A special category of HIV-1 microbicides are those based on proteins or peptides that interfere with the earliest steps in the viral infectious cycle. Besides a high degree of target specificity and a limited, if any, systemic absorption, proteinbased microbicides offer the unique advantage of being suitable to in vivo expression by engineered bacteria or viral vectors, which might ensure prolonged protection without the need for planned, intercourse-coordinated application. In this respect, vaginal or rectal microbiota such as Lactobacillus spp. represent ideal expression systems as they would not only produce the inhibitor of choice at the mucosal surface, but also easily blend within the resident microflora and offer additional valuable homeostatic effects. In this article, we review the current state of the art on protein-based microbicides.