Oral preexposure prophylaxis for HIV--another arrow in the quiver?

Ethical Implications of Social Stigma Associated with the Promotion and Use of Pre-Exposure Prophylaxis for HIV Prevention

Identifying sources of and eliminating social stigma associated with the promotion and use of pre-exposure prophylaxis (PrEP) for the prevention of sexually acquired HIV infection among men who have sex with men (MSM) is both a moral imperative and necessary requirement to ensure that public health objectives of HIV prevention can be met. This article will examine and address ethical concerns and criticisms regarding the use of PrEP, barriers to its promotion, and use among MSM and examine the types of social stigma associated with PrEP. An ethical justification for both healthcare and LGBT communities to address and overcome social stigma regarding the use of PrEP among MSM is offered.

Passing the baton: Community-based ethnography to design a randomized clinical trial on the effectiveness of oral pre-exposure prophylaxis for HIV prevention among Black men who have sex with men

Although HIV interventions and clinical trials increasingly report the use of mixed methods, studies have not reported on the process through which ethnographic or qualitative findings are incorporated into RCT designs. We conducted a community-based ethnography on social and structural factors that may affect the acceptance of and adherence to oral pre-exposure prophylaxis (PrEP) among Black men who have sex with men (BMSM). We then devised the treatment arm of an adherence clinical trial drawing on findings from the community-based ethnography. This article describes how ethnographic findings informed the RCT and identifies distilled themes and findings that could be included as part of an RCT. The enhanced intervention includes in-person support groups, online support groups, peer navigation, and text message reminders. By describing key process-related facilitators and barriers to conducting meaningful mixed methods research, we provide important insights for the practice of designing clinical trials for 'real-world' community settings.

Stakeholder Engagement in HIV Cure Research: Lessons Learned from Other HIV Interventions and the Way Forward

Clinical and basic science advances have raised considerable hope for achieving an HIV cure by accelerating research. This research is dominated primarily by issues about the nature and design of current and future clinical trials. Stakeholder engagement for HIV cure remains in its early stages. Our analysis examines timing and mechanisms of historical stakeholder engagement in other HIV research areas for HIV-uninfected individuals [vaccine development and pre-exposure prophylaxis (PrEP)], and HIV-infected individuals (treatment as prevention, prevention of mother-to-child transmission, and treatment of acute HIV infection) and articulate a plan for HIV cure stakeholder engagement. The experience from HIV vaccine development shows that early engagement of stakeholders helped manage expectations, mitigating the failure of several vaccine trials, while paving the way for subsequent trials. The relatively late engagement of HIV stakeholders in PrEP research may partly explain some of the implementation challenges. The treatment-related stakeholder engagement was strong and community-led from the onset and helped translation from research to implementation. We outline five steps to initiate and sustain stakeholder engagement in HIV cure research and conclude that stakeholder engagement represents a key investment in which stakeholders mutually agree to share knowledge, benefits, and risk of failure. Effective stakeholder engagement prevents misconceptions. As HIV cure research advances from early trials involving subjects with generally favorable prognosis to studies involving greater risk and uncertainty, success may depend on early and deliberate engagement of stakeholders.

[Study of human immunodeficiency virus transmission chains in Andalusia: analysis from baseline antiretroviral resistance sequences]

INTRODUCTION AND OBJECTIVE

Protease and reverse transcriptase HIV-1 sequences provide useful information for patient clinical management, as well as information on resistance to antiretrovirals. The aim of this study is to evaluate transmission events, transmitted drug resistance, and to georeference subtypes among newly diagnosed patients referred to our center.

METHODS

A study was conducted on 693 patients diagnosed between 2005 and 2012 in Southern Spain. Protease and reverse transcriptase sequences were obtained for resistance to cART analysis with Trugene(®) HIV Genotyping Kit (Siemens, NAD). MEGA 5.2, Neighbor-Joining, ArcGIS and REGA were used for subsequent analysis.

RESULTS

The results showed 298 patients clustered into 77 different transmission events. Most of the clusters were formed by pairs (n=49), of men having sex with men (n=26), Spanish (n=37), and below 45 years of age (73.5%). Urban areas from Granada, and the coastal areas of Almeria and Granada showed the greatest subtype heterogeneity. Five clusters were formed by more than 10 patients, and 15 clusters had transmitted drug resistance.

CONCLUSIONS

The study data demonstrate how the phylogenetic characterization of transmission clusters is a powerful tool to monitor the spread of HIV, and may contribute to design correct preventive measures to minimize it.

STD patients' preferences for HIV prevention strategies

The objective of this pilot study was to explore the knowledge of and preferences regarding effective biomedical interventions among high risk individuals attending a sexually transmitted diseases clinic, and to examine the effect of a brief information intervention on preference. Participants completed a baseline assessment, attended a presentation on human immunodeficiency virus (HIV) prevention methods, and completed a postintervention assessment. Outcome measures included: demographics and sexual risk factors, self-perceived HIV risk, and knowledge and attitudes regarding new biomedical methods of HIV prevention. After the baseline evaluation, participants were provided with information on new biomedical prevention strategies. Participants were given the option to review the information by reading a pamphlet or by viewing a brief video containing the same information. Participants (n=97) were female (n=51) and male (n=46). At baseline, only a small minority of participants were aware of the newer biomedical strategies to prevent HIV infection. Postintervention, 40% endorsed having heard about the use of HIV medications to prevent HIV infection; 72% had heard that male circumcision can decrease the risk of acquiring HIV infection in men; and 73% endorsed knowledge of the potential role of microbicides in decreasing the risk of acquiring HIV. Following the intervention, the most preferred prevention method was male condoms, followed by preexposure prophylaxis, and microbicides. The least preferred methods were male circumcision and female condoms. This study provides preliminary information on knowledge and attitudes regarding newer biomedical interventions to protect against HIV infection.

Preexposure prophylaxis will have a limited impact on HIV-1 drug resistance in sub-Saharan Africa: a comparison of mathematical models

BACKGROUND

Preexposure prophylaxis (PrEP) with tenofovir and emtricitabine can prevent new HIV-1 infections, but there is a concern that use of PrEP could increase HIV drug resistance resulting in loss of treatment options. We compared standardized outcomes from three independent mathematical models simulating the impact of PrEP on HIV transmission and drug resistance in sub-Saharan African countries.

METHODS

All models assume that people using PrEP receive an HIV test every 3-6 months. The models vary in structure and parameter choices for PrEP coverage, effectiveness of PrEP (at different adherence levels) and the rate with which HIV drug resistance emerges and is transmitted.

RESULTS

The models predict that the use of PrEP in conjunction with antiretroviral therapy will result in a lower prevalence of HIV than when only antiretroviral therapy is used. With or without PrEP, all models suggest that HIV drug resistance will increase over the next 20 years due to antiretroviral therapy. PrEP will increase the absolute prevalence of drug resistance in the total population by less than 0.5% and amongst infected individuals by at most 7%. Twenty years after the introduction of PrEP, the majority of drug-resistant infections is due to antiretroviral therapy (50-63% across models), whereas 40-50% will be due to transmission of drug resistance, and less than 4% to the use of PrEP.

CONCLUSION

HIV drug resistance resulting from antiretroviral therapy is predicted to far exceed that resulting from PrEP. Concern over drug resistance should not be a reason to limit the use of PrEP.

TSPY4 is a novel sperm-specific biomarker of semen exposure in human cervicovaginal fluids; potential use in HIV prevention and contraception studies

BACKGROUND

Developing an objective, reliable method to determine semen exposure in cervicovaginal fluids is important for accurately studying the efficacy of vaginal microbicides and contraceptives. Y-chromosome biomarkers offer better stability, sensitivity, and specificity than protein biomarkers. TSPY4 belongs to the TSPY (testis-specific protein Y-encoded) family of homologous genes on the Y-chromosome. Using a multiplex PCR amplifying TSPY4, amelogenin, and Sex-determining region in the Y chromosome (SRY), our objective was to determine whether a gene in the TSPY family was a more sensitive marker of semen exposure in cervicovaginal fluids than SRY.

STUDY DESIGN

The multiplex polymerase chain reaction (PCR) was developed using sperm and vaginal epithelial (female) DNA. Diluted sperm DNA and mixed male/female DNA was used to determine the sensitivity of the multiplex PCR. Potential interference of TSPY4 amplification by components in cervicovaginal and seminal fluids was determined. TSPY4 and SRY amplification was also investigated in women participating in a separate IRB-approved clinical study in which cervicovaginal swab DNA was collected before semen exposure and at various time points after exposure.

RESULTS

TSPY4, SRY, and amelogenin were amplified in sperm DNA, but only amelogenin in female DNA. The limit of sperm DNA from which TSPY4 could be amplified was lower than SRY (4 pg vs 80 pg). TSPY4 could also be amplified from mixed male/female DNA. Amplification was not affected by cervicovaginal and seminal components. Using cervicovaginal swab DNA from three women before and after semen exposure, TSPY4 was detected up to 72 h post exposure while SRY detection was observed up to 24-48 h. TSPY4 was detected up to 7 days post exposure in one out of three women.

CONCLUSIONS

We have demonstrated that TSPY4 is a new sensitive, and sperm-specific biomarker. The multiplex PCR incorporating this new biomarker has potential to be an objective measure for determining semen exposure in clinical trials of vaginal products such as contraceptives and HIV pre/post-exposure prophylaxis agents.

HIV and chemoprophylaxis, the importance of considering social structures alongside biomedical and behavioral intervention

This manuscript draws connections between chemoprophylaxis and the biomedical model of disease that emphasizes individual behavior. We argue that chemoprophylactic HIV interventions have limited utility at the population-level, and that structural interventions need to be prioritized. We use the recent CAPRISA 004 and iPrEx trials to (a) critique the utility of these trials from a public health perspective by highlighting the difference between efficacy and effectiveness, (b) apply an alternative theory of health behavior as a way to reorient the field toward the discussion of the need to employ structural interventions, and (c) examine two aspects of HIV prevention efforts - funding structures and iatrogenic effects of biomedical approaches - as a means of overcoming obstacles to more widespread adoption of structural interventions.

Preconception and contraceptive care for women living with HIV

Women living with HIV have fertility desires and intentions that are similar to those of uninfected women, and with advances in treatment most women can realistically plan to have and raise children to adulthood. Although HIV may have adverse effects on fertility, recent studies suggest that antiretroviral therapy may increase or restore fertility. Data indicate the increasing numbers of women living with HIV who are becoming pregnant, and that many pregnancies are unintended and contraception is underutilized, reflecting an unmet need for preconception care (PCC). In addition to the PCC appropriate for all women of reproductive age, women living with HIV require comprehensive, specialized care that addresses their unique needs. The goals of PCC for women living with HIV are to prevent unintended pregnancy, optimize maternal health prior to pregnancy, improve maternal and fetal outcomes in pregnancy, prevent perinatal HIV transmission, and prevent HIV transmission to an HIV-uninfected sexual partner when trying to conceive. This paper discusses the rationale for preconception counseling and care in the setting of HIV and reviews current literature relevant to the content and considerations in providing PCC for women living with HIV, with a primary focus on well-resourced settings.

A qualitative study of provider thoughts on implementing pre-exposure prophylaxis (PrEP) in clinical settings to prevent HIV infection

Background

A recent clinical trial demonstrated that a daily dose tenofovir disoproxil fumarate and emtricitabrine (TDF-FTC) can reduce HIV acquisition among men who have sex with men (MSM) and transgender (TG) women by 44%, and up to 90% if taken daily. We explored how medical and service providers understand research results and plan to develop clinical protocols to prescribe, support and monitor adherence for patients on PrEP in the United States.

Methods

Using referrals from our community collaborators and snowball sampling, we recruited 22 healthcare providers in San Francisco, Oakland, and Los Angeles for in-depth interviews from May-December 2011. The providers included primary care physicians seeing high numbers of MSM and TG women, HIV specialists, community health clinic providers, and public health officials. We analyzed interviews thematically to produce recommendations for setting policy around implementing PrEP. Interview topics included: assessing clinician impressions of PrEP and CDC guidance, considerations of cost, office capacity, dosing schedules, and following patients over time.

Results

Little or no demand for PrEP from patients was reported at the time of the interviews. Providers did not agree on the most appropriate patients for PrEP and believed that current models of care, which do not involve routine frequent office visits, were not well suited for prescribing PrEP. Providers detailed the need to build capacity and were concerned about monitoring side effects and adherence. PrEP was seen as potentially having impact on the epidemic but providers also noted that community education campaigns needed to be tailored to effectively reach specific vulnerable populations.

Conclusions

While PrEP may be a novel and clinically compelling prevention intervention for MSM and TG women, it raises a number of important implementation challenges that would need to be addressed. Nonetheless, most providers expressed optimism that they eventually could prescribe and monitor PrEP in their practice.

HIV risk perception and preexposure prophylaxis interest among a heterosexual population visiting a sexually transmitted infection clinic

Low perception of HIV risk despite behaviors associated with increased risk is thought to be a contributing factor for a higher prevalence of HIV in blacks than other groups in the United States. We sought to determine HIV risk perception and its impact on safer sex practices and interest in preexposure prophylaxis (PrEP). From August 1 to October 31, 2010, an anonymous survey was conducted at a sexually transmitted infection clinic asking questions about demographics, risk behaviors, and PrEP interest. Participants were categorized into high-risk, moderate-risk, and low-risk groups according to predefined HIV risk characteristics. Only heterosexual high-risk participants were further assessed for their risk perception, condom use and PrEP interest. There were 494 participants; 63% male, 70% blacks, 88% heterosexual; 83% were categorized into the high-risk group. Of the 359 heterosexual high-risk participants, 301 (84%) perceived themselves at no or low-risk. Rates of consistent condom use with vaginal, oral, and anal sex were low (<20%) in this group despite high levels of knowledge about HIV transmission risks. Rates of condom use were not affected by risk perception. No interest in PrEP was associated with low education level (adjusted odds ratio 4.97; p=0.02) and low risk perception. These findings suggest that despite having knowledge about HIV transmission risks, the majority of high-risk participants did not recognize their risks and used condoms with low frequency. Low risk perception and low education level may impact PrEP interest. Enhanced interventions are needed to improve HIV risk perception, safer sex practices, and knowledge about PrEP.

Willingness to accept HIV pre-exposure prophylaxis among Chinese men who have sex with men

Objective

We investigated the awareness and acceptability of pre-exposure prophylaxis (PrEP) among men who have sex with men (MSM) and potential predicting factors.

Methods

This study was conducted among MSM in Beijing, China. Study participants, randomly selected from an MSM cohort, completed a structured questionnaire, and provided their blood samples to test for HIV infection and syphilis. Univariate logistic regression analyses were performed to evaluate the factors associated with willingness to accept (WTA) PrEP. Factors independently associated with willingness to accept were identified by entering variables into stepwise logistic regression analysis.

Results

A total of 152 MSM completed the survey; 11.2% had ever heard of PrEP and 67.8% were willing to accept it. Univariate analysis showed that age, years of education, consistent condom use in the past 6 months, heterosexual behavior in the past 6 months, having ever heard of PrEP and the side effects of antiretroviral drugs, and worry about antiretroviral drugs cost were significantly associated with willingness to accept PrEP. In the multivariate logistic regression model, only consistent condom use in the past 6 months (odds ratio [OR]: 0.31; 95% confidence interval [CI]: 0.13–0.70) and having ever heard of the side effects of antiretroviral drugs (OR: 0.30; 95% CI: 0.14–0.67) were independently associated with willingness to accept PrEP.

Conclusions

The awareness of PrEP in the MSM population was low. Sexual behavioral characteristics and knowledge about ART drugs may have effects on willingness to accept PrEP. Comprehensive prevention strategies should be recommended in the MSM community.

HIV-1 treatment as prevention: the good, the bad, and the challenges

PURPOSE OF REVIEW

This work focuses on the use of antiretroviral agents to prevent the sexual transmission of HIV-1.

RECENT FINDINGS

Two randomized clinical trials demonstrated that antiretroviral agents provided before exposure to HIV-1 offer substantial protection, ostensibly directly proportional to the concentration of antiretroviral therapy (ART) in the genital secretions. Intense focus on the use of HIV treatment as prevention has led to publication of modeling exercises, ecological studies, and observational studies, most of which support the potential benefits of ART. However, the logistical requirements for successful use of ART for prevention are considerable.

SUMMARY

ART will serve as a cornerstone of combination prevention of HIV-1. Continued research will be essential to measure anticipated benefits and to detect implementation barriers and untoward consequences of such a program, especially increases in primary ART resistance.

Dilemma of concepts and strategies for the prevention of spread of HIV in relation to human behavior, law and human rights

The new prevalence data regarding the estimated global number of human immunodeficiency virus positive (HIV+) cases, i.e., including people who are either aware or unaware of their HIV infection in 2010, lead many to wonder why the increase in incidence has reached today's unprecedented level and escalated within such a short time. This, in spite of prevention campaigns in countries affected by HIV/acquired immune deficiency syndrome (AIDS) with their urgent messages aimed at preventing HIV transmission by promoting changes in individual's behavior. This article analyzes the background of the prevention strategies, in particular their political, social and legal concepts in terms of human rights, and reveals traits of human behavior not considered thus far. A radical reappraisal is necessary, at social and legislative levels, as well as options additional to current concepts. When ethical issues come up, they become blamed for outmoded moralistic positions. However, ignoring the reality has led to dire consequences from prioritizing individual human rights over society's collective need to prevent the spread of HIV.

The potential impact of an HIV vaccine with limited protection on HIV incidence in Thailand: a modeling study

BACKGROUND

The RV144 trial on the ALVAC/AIDSVAX candidate HIV vaccine, carried out in Thailand, showed short-lived protection against infection.

METHODS

Using a deterministic compartmental model we explored the potential impact of this vaccine on heterosexual HIV transmission in Thailand. Both one-off vaccination strategies, as well as strategies with regular boosting, either annually or every two years, were explored. Both targeting the general adult population and prioritizing sex workers were modeled. The impact of risk compensation among high risk groups, as well as whether higher levels of safe sex in high risk groups could be an alternative to vaccination, was studied.

RESULTS

One-off vaccination campaigns had only transient effects, and boosting appears to be a key component of successful vaccination campaigns. Intensive vaccination campaigns may reduce HIV incidence by up to 75% after 10 years of vaccination. Targeting only sex workers has a smaller impact but has a more favorable cost-benefit ratio. Risk compensation has the potential of undoing much of the benefits of a vaccination program and may even increase incidence. In contrast, higher levels of safe sex among sex workers would provide a viable alternative to vaccinating this group.

DISCUSSION

The new vaccine holds promise for controlling HIV in Thailand and similar countries. In view of the short lived protection of the vaccine, regular boosting of immunity as well as avoidance of risk compensation are essential. Targeting sex workers would achieve the greatest reduction in incidence per vaccination and may be considered for expensive vaccines but its cost-effectiveness has to be compared to alternatives.

What do mathematical models tell us about the emergence and spread of drug-resistant HIV?

PURPOSE OF REVIEW

To discuss recent HIV epidemic models examining the transmission of antiretroviral (ARV) drug resistance.

RECENT FINDINGS

A relatively small number of recent transmission models have investigated ARV resistance in the context of therapeutic, combined ART (cART); ARV-vaginal microbicides (ARV-VMB); and oral pre-exposure prophylaxis (PrEP). Models of cART use have highlighted potential concerns about future resistance transmission, particularly in resource-constrained settings, and have emphasized the benefits of viral load monitoring in limiting resistance spread. PrEP models have concluded that inadvertent use by HIV-infected individuals could increase resistance prevalence, and that risk compensation by PrEP users could limit their beneficial effects on HIV transmission. ARV-VMB models have demonstrated that whereas resistance can reduce prophylactic effectiveness in preventing HIV acquisition of female ARV-VMB users, it may concomitantly benefit users' male partners if the resistant strains that female users acquire are less transmissible than wild-type strains. The models have examined the balance between these two factors at the population level.

SUMMARY

Recent HIV transmission models have adopted a wide assortment of structures and assumptions to explore drug resistance in the context of different ARV interventions in various settings. There is a need for future work emphasizing the simultaneous effects of multiple ARV interventions, as well as the public health impact of resistance, not just its prevalence.