HIV-1 drug resistance in the iPrEx preexposure prophylaxis trial

Low clinical impact of HIV drug resistance mutations in oral pre-exposure prophylaxis: a systematic review and meta-analysis

INTRODUCTION

Despite the widespread use of pre-exposure prophylaxis (PrEP) in preventing human immunodeficiency virus (HIV) transmission, scant information on HIV drug resistance mutations (DRMs) has been gathered over the past decade. This review aimed to estimate the pooled prevalence of pre-exposure prophylaxis and its two-way impact on DRM.

METHODS

We systematically reviewed studies on DRM in pre-exposure prophylaxis according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis 2020 guidelines. PubMed, Cochrane, and SAGE databases were searched for English-language primary studies published between January 2001 and December 2023. The initial search was conducted on 9 August 2021 and was updated through 31 December 2023 to ensure the inclusion of the most recent findings. The registration number for this protocol review was CRD42022356061.

RESULTS

A total of 26,367 participants and 562 seroconversion cases across 12 studies were included in this review. The pooled prevalence estimate for all mutations was 6.47% (95% Confidence Interval-CI 3.65-9.93), while Tenofovir Disoproxil Fumarate/Emtricitabine-associated drug resistance mutation prevalence was 1.52% (95% CI 0.23-3.60) in the pre-exposure prophylaxis arm after enrolment. A subgroup analysis, based on the study population, showed the prevalence in the heterosexual and men who have sex with men (MSM) groups was 5.53% (95% CI 2.55-9.40) and 7.47% (95% CI 3.80-12.11), respectively. Notably, there was no significant difference in the incidence of DRM between the pre-exposure prophylaxis and placebo groups (log-OR = 0.99, 95% CI -0.20 to 2.18, I2 = 0%; p = 0.10).

DISCUSSION

Given the constrained prevalence of DRM, the World Health Organization (WHO) advocates the extensive adoption of pre-exposure prophylaxis. Our study demonstrated no increased risk of DRM with pre-exposure prophylaxis (p > 0.05), which is consistent with these settings. These findings align with the previous meta-analysis, which reported a 3.14-fold higher risk in the pre-exposure prophylaxis group than the placebo group, although the observed difference did not reach statistical significance (p = 0.21).

CONCLUSIONS

Despite the low prevalence of DRM, pre-exposure prophylaxis did not significantly increase the risk of DRM compared to placebo. However, long-term observation is required to determine further disadvantages of extensive pre-exposure prophylaxis use. PROSPERO Number: CRD42022356061.

Optimising HIV pre-exposure prophylaxis and testing strategies in men who have sex with men in Australia, Thailand, and China: a modelling study and cost-effectiveness analysis

BACKGROUND

Men who have sex with men (MSM) in the Asia-Pacific region have a disproportionately high burden of HIV infection compared with the general population. Although pre-exposure prophylaxis (PrEP) for HIV is highly effective at preventing new HIV infections, the cost-effectiveness of PrEP for MSM in different countries in the Asia-Pacific region with varying PrEP coverage and HIV testing frequencies remains unstudied. We aimed to analyse the economic and health benefits of long-acting injectable cabotegravir (CAB-LA) compared with oral PrEP in high-income countries and low-income and middle-income countries within the Asia-Pacific region.

METHODS

We developed a decision-analytic Markov model to evaluate the population impact and cost-effectiveness of PrEP scale-up among MSM in Australia, Thailand, and China. We assumed a static cohort of 100 000 MSM aged 18 years or older who were at risk of HIV infection, with a monthly cycle length over a 40-year time period. We evaluated hypothetical scenarios with universal PrEP coverage of 80% among 100 000 suitable MSM in each country. We modelled oral PrEP and CAB-LA for MSM with diverse HIV testing frequency strategies. We adopted the health-care system's perspective with a 3% annual discount rate. We calculated the incremental cost-effectiveness ratio (ICER), measured as additional cost per quality-adjusted life-year (QALY) gained, to compare different strategies with the status quo in each country. All costs were reported in 2021 US$. We also performed one-way, two-way, and probabilistic sensitivity analyses to assess the robustness of our findings.

FINDINGS

Compared with the status quo in each country, expanding oral PrEP to 80% of suitable MSM would avert 8·1% of new HIV infections in Australia, 14·5% in Thailand, and 26·4% in China in a 40-year period. Expanding oral PrEP use with 6-monthly HIV testing for both PrEP and non-PrEP users was cost-saving for Australia. Similarly, expanding oral PrEP use remained the most cost-effective strategy in both Thailand and China, but optimal testing frequency varied, with annual testing in Thailand (ICER $4707 per QALY gained) and 3-monthly testing in China (ICER $16 926 per QALY gained) for both PrEP and non-PrEP users. We also found that replacing oral PrEP with CAB-LA for MSM could avert more new HIV infections (12·8% in Australia, 27·6% in Thailand, and 32·8% in China), but implementing CAB-LA was not cost-effective due to its high cost. The cost of CAB-LA would need to be reduced by 50-90% and be used as a complementary strategy to oral PrEP to be cost-effective in these countries.

INTERPRETATION

Expanding oral PrEP use for MSM, with country-specific testing frequency, is cost-effective in Australia, Thailand, and China. Due to the high cost, CAB-LA is currently not affordable as a single-use strategy but might be offered as an additional option to oral PrEP.

FUNDING

Ministry of Science and Technology of the People's Republic of China, the Australian National Health and Medical Research Council, National Key Research and Development Program of China, and National Natural Science Foundation of China.

Laboratory diagnosis of HIV: a contemporary overview in the Australian context

Over the past decade there have been technical advances in human immunodeficiency virus (HIV) assays and updates to testing regulations that have substantially changed the landscape of laboratory testing for HIV. In addition, there have been significant changes in the epidemiology of HIV in Australia in the context of highly effective contemporary biomedical treatment and prevention strategies. Here, we provide an update on contemporary issues for the laboratory detection and confirmation of HIV in Australia. These include (1) the impact of early treatment and biological prevention strategies on the serological and virological detection of HIV; (2) the updated national HIV laboratory case definition and its interaction with testing regulations, public health and clinical guidelines; and (3) novel strategies for the laboratory detection of HIV, including the incorporation of HIV nucleic acid amplification tests (NAATs) into testing algorithms. These developments present an opportunity to develop a nationally consistent contemporary HIV testing algorithm that would result in optimisation and standardisation of HIV testing in Australia.

How could HIV-1 drug resistance impact preexposure prophylaxis for HIV prevention?

PURPOSE OF REVIEW

To review current laboratory and clinical data on the frequency and relative risk of drug resistance and range of mutations selected from approved and investigational antiretroviral agents used for preexposure prophylaxis (PrEP) of HIV-1 infection, including tenofovir disproxil fumarate (TDF)-based oral PrEP, dapivirine ring, injectable cabotegravir (CAB), islatravir, lenacapavir and broadly neutralizing antibodies (bNAbs).

RECENT FINDINGS

The greatest risk of HIV-1 resistance from PrEP with oral TDF/emtricitabine (FTC) or injectable CAB is from starting or continuing PrEP after undiagnosed acute HIV infection. By contrast, the dapivirine intravaginal ring does not appear to select nonnucleoside reverse transcriptase inhibitor resistance in clinical trial settings. Investigational inhibitors including islatravir, lenacapavir, and bNAbs are promising for use as PrEP due to their potential for sustained delivery and low risk of cross-resistance to currently used antiretrovirals, but surveillance for emergence of resistance mutations in more HIV-1 gene regions (gag, env) will be important as the same drugs are being developed for HIV therapy.

SUMMARY

PrEP is highly effective in preventing HIV infection. Although HIV drug resistance from PrEP use could impact future options in individuals who seroconvert on PrEP, the current risk is low and continued monitoring for the emergence of resistance and cross-resistance during product development, clinical studies, and product roll-out is advised to preserve antiretroviral efficacy for both treatment and prevention.

A comparison of attitudes and knowledge of pre-exposure prophylaxis (PrEP) between hospital and Key Population Led Health Service providers: Lessons for Thailand's Universal Health Coverage implementation

BACKGROUND

HIV Pre-exposure prophylaxis (PrEP) has demonstrated efficacy and effectiveness among high-risk populations. In Thailand, PrEP has been included in the National Guidelines on HIV/AIDS Treatment and Prevention since 2014. As a part of the national monitoring and evaluation framework for Thailand's universal coverage inclusion, this cross-sectional survey was conducted to assess knowledge of, attitudes to and practice (KAP) of PrEP service providers in Thailand.

METHODS

We conducted a cross-sectional survey to explore knowledge of, and attitudes towards PrEP among providers from hospital and Key Population Led Health Services (KPLHS) settings. The questionnaire was distributed online in July 2020. Descriptive and univariate analysis using an independent-sample t-test were applied in the analyses. Attitudes were ranked from the most negative (score of 1) to the most positive (score of 5).

RESULTS

Overall, there were 196 respondents (158 from hospitals and 38 from KPLHS) in which most hospital providers are female nurse practitioners while half of those from KPLHS report current gender as gay. Most respondents report a high level of PrEP knowledge and support provision in all high-risk groups with residual concern regarding anti-retroviral drugs resistance. Over two-fifths of providers from both settings perceive that PrEP would result in risk compensation and half of KPLHS providers are concerned regarding risk of sexual transmitted infections. Limited PrEP counselling time is a challenge for hospital providers.

CONCLUSIONS

Service integration between both settings, more involvement and distribution of KPLHS in reaching key populations would be essential in optimizing PrEP uptake and retention. Continuing support particularly in raising awareness about PrEP among healthcare providers and key populations, facilities and manpower, unlimited quota of patient recruitment and PrEP training to strengthen providers' confidence and knowledge would be essential for successful PrEP implementation.

Immediate PrEP after PEP: Results from an Observational Nurse-Led PEP2PrEP Study

Patients who use post-exposure prophylaxis (PEP) are at ongoing risk for HIV acquisition after completing PEP. While the Centers for Disease Control and Prevention recommends pre-exposure prophylaxis (PrEP) use immediately after PEP, some practitioners are hesitant to offer PEP-to-PrEP (PEP2PrEP). We began offering PEP2PrEP in the sexually transmitted infection clinic in Ottawa, Canada on August 5, 2018. During the first 16 months of PEP2PrEP, 61 patients requested PEP and 46 were initiated; 30 of these patients agreed to PEP2PrEP and 26 followed through. None of our PEP patients had confirmed HIV exposures; all fulfilled the initiation criterion of condomless anal sex with a male partner of unknown HIV-status. During the study, the number of PEP requests and initiations was statistical unchanged, yet the seroconversion rate among patients who used PEP decreased from 1.7% pre-PEP2PrEP to 0% post-PEP2PrEP. Regarding follow-up, most discontinuations occurred between the PrEP intake and 1-month follow-up visit.

Use of Drug-level Testing and Single-genome Sequencing to Unravel a Case of Human Immunodeficiency Virus Seroconversion on Pre-exposure Prophylaxis

Cases of seroconversion on pre-exposure prophylaxis (PrEP) should be carefully investigated, given their public health implications and rarity. We report a case of transmitted drug resistance causing seroconversion on PrEP in spite of high adherence, confirmed with dried blood spot and segmental hair drug-level testing and single-genome sequencing.

Nondaily Use of HIV Preexposure Prophylaxis in a Large Online Survey of Primarily Men Who Have Sex With Men in the United States

BACKGROUND

Event-driven dosing of HIV preexposure prophylaxis (PrEP) using a 2-1-1 regimen is efficacious for men who have sex with men (MSM). However, data are limited on the prevalence, correlates, and patterns of nondaily PrEP use in the United States.

SETTING

Nationwide online survey.

METHODS

We distributed a survey to assess experiences with PrEP, including nondaily use, in May 2019 on geosocial networking sites commonly used by MSM.

RESULTS

Among 9697 respondents, the mean age was 43 years, 67% were non-Hispanic white, and 90% were MSM. Nearly all (91.0%) had heard of PrEP, 40.1% ever used PrEP, and 33.3% used PrEP in the past 6 months. Most (60.6%) were interested in nondaily PrEP. Those without health insurance and those with higher incomes were more likely to be interested in nondaily PrEP. Of the 3232 who used PrEP in the past 6 months, 176 (5.4%) reported nondaily use. Fewer sexual partners, frequent sex planning, and substance use were associated with nondaily use. Common reasons for nondaily use were inconsistent sexual activity (59%) and cost (49%). The most prevalent regimen was event driven (48.3%); of those, 64.7% used 2-1-1. Of nondaily users, 24.0% used PrEP on a regular schedule but not every day, including only on weekends or days starting with T or S.

CONCLUSIONS

Given substantial interest in nondaily PrEP, and use of nondaily strategies that have not been evaluated in clinical studies, there is a need for US public health authorities to provide guidance on safe and effective nondaily dosing for MSM.

Primary HIV-1 infection in users of pre-exposure prophylaxis

Pre-exposure prophylaxis (PrEP) has proven to be a highly effective and safe way to prevent HIV infection. Seroconversion and primary HIV infection are exceptional if adherence to PrEP is good. However, primary HIV infection while using PrEP can occur, albeit rarely, and HIV drug resistance might develop. Furthermore, the scope of PrEP is expected to expand, and clinicians might face potential seroconversions and primary HIV infection in patients starting or taking PrEP. The characteristics of primary HIV infection in users of PrEP are poorly described. PrEP users present a lower viral load peak during primary HIV infection and, frequently, fewer symptoms than individuals not exposed to PrEP. Additionally, PrEP prolongs the stages of seroconversion, thus potentially complicating diagnosis of primary HIV infection. Drug resistance is rare, occurring mostly when PrEP is initiated in undiagnosed patients who are at an extremely early stage of infection, in whom detection of HIV-RNA was not used to rule out HIV infection. Therefore, careful exclusion of primary HIV infection before starting PrEP is crucial. In patients presenting with primary HIV infection while on PrEP, a drug with a high genetic barrier (or even two) should be added to tenofovir disoproxil fumarate-emtricitabine until test results for resistance are available.

Same-day prescribing of daily oral pre-exposure prophylaxis for HIV prevention

Pre-exposure prophylaxis (PrEP) is highly effective in reducing HIV transmission but remains underutilised globally. Same-day PrEP prescribing and medication provision is an emerging implementation approach. The experiences of the three same-day PrEP programmes support the feasibility of the approach. Key elements of safe and effective same-day PrEP programmes include the ability to order laboratory tests at the time of the clinical visit and the ability to contact patients when laboratory results are available. Same-day PrEP has the potential to alleviate the attrition seen in usual care between initial evaluation and receipt of a PrEP prescription. A widespread application of same-day prescribing will be needed to assess its effect on PrEP usage.

Importance of early identification of PrEP breakthrough infections in a generalized HIV epidemic: a case report from a PrEP demonstration project in South Africa

Background

The World Health Organisation recommends the use of tenofovir-containing pre-exposure prophylaxis (PrEP) as an additional Human Immunodeficiency Virus (HIV) prevention choice for men and women at substantial risk of HIV infection. PrEP could fill an important HIV prevention gap, especially for sexually active young women who are limited in their ability to negotiate mutual monogamy or condom use.

As PrEP is scaled up in high HIV incidence settings, it is crucial to consider the importance of early identification of HIV infection during PrEP use, to allow for rapid discontinuation of PrEP to reduce the risk of antiretroviral (ARV) resistance. The purpose of this case study is to provide this critical evidence.

Case presentation

This report describes a 20-year-old woman in a HIV sero-discordant relationship who initiated oral PrEP (tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC)) through a demonstration project (CAPRISA 084) in October 2017. Despite good adherence throughout her PrEP use, she tested HIV antibody positive at month nine of study participation.

Retrospective testing showed increasing HIV viral load over time, and retrospective use of fourth-generation rapid HIV tests showed HIV detection (positive antigen/antibody) at month one. Sequencing confirmed a dominant wild type at month one with dual therapy resistance patterns emerging by month three (M184V and K65R mutations), which is suggestive of protracted PrEP use during an undetected HIV infection.

The participant was referred to infectious diseases for further management of her HIV infection and was initiated on a first line, tenofovir-sparing regimen. At the time of this report (January 2020), the participant had been on ARV- therapy (ART) for 13 months and had no signs of either clinical, immunologic or virologic failure.

Conclusions

This case report highlights the importance of appropriate HIV screening during wider oral PrEP scale-up in high HIV incidence settings to circumvent the consequences of prolonged dual therapy in an undiagnosed HIV infection and in turn prevent ARV resistance.

Genotypic Methods for HIV Drug Resistance Monitoring: The Opportunities and Challenges Faced by China

AIDS is a globalized infectious disease. In 2014, UNAIDS launched a global project of "90-90-90" to end the HIV epidemic by 2030. The second and third 90 require 90% of HIV-1 infected individuals receiving antiretroviral therapy (ART) and durable virological suppression. However, wide use of ART will greatly increase the emergence and spreading of HIV drug resistance and current HIV drug resistance test (DRT) assays in China are seriously lagging behind, hindering to achieve virological suppression. Therefore, recommending an appropriate HIV DRT method is critical for HIV routine surveillance and prevention in China. In this review, we summarized the current existing HIV drug resistance genotypic testing methods around the world and discussed the advantages and disadvantages of these methods.

Brief Report: Incidence of HIV in a Nationwide Cohort Receiving Pre-exposure Prophylaxis for HIV Prevention

BACKGROUND

Cases of HIV, while infrequent, have been reported during tenofovir disoproxil fumarate/emtricitabine use as pre-exposure prophylaxis (PrEP). We describe the incidence of HIV and patterns of PrEP use within the Veterans Health Administration (VHA).

METHODS

We conducted a retrospective cohort study among persons initiating PrEP in the VHA between July 2012 and April 2016 using national VHA data. We defined time on PrEP and time at risk of HIV exposure as the total time from the first PrEP fill to exhaustion of supply of the final PrEP prescription. We identified incident cases of HIV infection after PrEP initiation based on laboratory data. Medication adherence measures and days without pills were calculated using pharmacy fill data. We used a chart review to determine patient-reported PrEP use around the time of diagnosis.

RESULTS

We identified 825 unique patients initiating PrEP; they were 97% men and 67% white, with a mean age of 41 years. Six HIV infections were observed during the study period, yielding an HIV incidence of 0.8 (Poisson exact 95% confidence interval: 0.3 to 1.8) cases per 100 person-years. Two cases occurred during active PrEP use by self-report and perfect adherence based on fill data. Both were infected with viruses containing the M184V mutation. Four additional cases were diagnosed after self-reported discontinuation.

CONCLUSIONS

HIV infection was rare in a nationwide cohort of PrEP users. Although most of the infections occurred during inconsistent PrEP use, infections during periods of high measured adherence were also observed. These findings highlight the importance of PrEP persistence during periods of risk.

The role of drug resistance in poor viral suppression in rural South Africa: findings from a population-based study

BACKGROUND

Understanding factors driving virological failure, including the contribution of HIV drug resistance mutations (DRM), is critical to ensuring HIV treatment remains effective. We examine the contribution of drug resistance mutations for low viral suppression in HIV-positive participants in a population-based sero-prevalence survey in rural South Africa.

METHODS

We conducted HIV drug resistance genotyping and ART analyte testing on dried blood spots (DBS) from HIV-positive adults participating in a 2014 survey in North West Province. Among those with virologic failure (> 5000 copies/mL), we describe frequency of DRM to protease inhibitors (PI), nucleoside reverse transcriptase inhibitors (NRTI), and non-nucleoside reverse transcriptase inhibitors (NNRTI), report association of resistance with antiretroviral therapy (ART) status, and assess resistance to first and second line therapy. Analyses are weighted to account for sampling design.

RESULTS

Overall 170 DBS samples were assayed for viral load and ART analytes; 78.4% of men and 50.0% of women had evidence of virologic failure and were assessed for drug resistance, with successful sequencing of 76/107 samples. We found ≥1 DRM in 22% of participants; 47% were from samples with detectable analyte (efavirenz, nevirapine or lopinavir). Of those with DRM and detectable analyte, 60% showed high-level resistance and reduced predicted virologic response to ≥1 NRTI/NNRTI typically used in first and second-line regimens.

CONCLUSIONS

DRM and predicted reduced susceptibility to first and second-line regimens were common among adults with ART exposure in a rural South African population-based sample. Results underscore the importance of ongoing virologic monitoring, regimen optimization and adherence counseling to optimize durable virologic suppression.

Scaling-up PrEP Delivery in Sub-Saharan Africa: What Can We Learn from the Scale-up of ART?

Purpose of Review

Clinical trials have found that PrEP is highly effective in reducing risk of HIV acquisition across types of exposure, gender, PrEP regimens, and dosing schemes. Evidence is urgently needed to inform scale-up of PrEP to meet the ambitious WHO/UNAIDS prevention target of 3,000,000 individuals on PrEP by 2020.

Recent Findings

Successful models of delivering HIV services at scale evolved from years of formal research and programmatic evidence. These efforts produced lessons-learned relevant for scaling-up PrEP delivery, including the importance of streamlining laboratory tests, expanding prescription and management authority, differentiating medication access points, and reducing stigma and barriers of parental consent for PrEP uptake. Further research is especially needed in areas differentiating PrEP from ART delivery, including repeat HIV testing to ensure HIV negative status and defining and measuring prevention-effective adherence.

Summary

Evidence from 15 years of ART scale-up could immediately inform a public health approach to PrEP delivery.

Drug Resistance During HIV Pre-Exposure Prophylaxis

Clinical studies have demonstrated that use of tenofovir disoproxil fumarate with or without emtricitabine as antiretroviral pre-exposure prophylaxis (PrEP) can decrease the risk of human immunodeficiency virus (HIV) acquisition when medication adherence is high. However, the potential for PrEP to promote antiretroviral resistance remains an important public health consideration. We performed a search of the medical literature to identify studies that address HIV drug resistance during PrEP use. In this review, we summarize findings about emergent drug resistance during clinical trials of PrEP, case reports of seroconversions in patients adherent to PrEP, and animal studies of PrEP effectiveness against drug-resistant viral strains. We also discuss the potential utility of novel PrEP formulations for protection against drug-resistant HIV, the impact of drug resistance on HIV treatment options, and mathematical models that estimate the potential contribution of PrEP to population-level drug resistance. Evidence suggests that selection for HIV drug resistance with PrEP use is infrequent and most likely to occur when PrEP is used during undiagnosed acute HIV infection. Breakthrough infections during PrEP use with high adherence are possible, but appear to be rare. The prevalence of drug-resistant HIV strains needs to be monitored as PrEP is scaled up. However, the benefit of a decreased HIV incidence with wider PrEP use is likely to outweigh the risk of harms from possible increases in the prevalence of HIV drug resistance.

Cost-Effectiveness of a Statewide Pre-Exposure Prophylaxis Program for Gay, Bisexual, and Other Men Who Have Sex with Men

Pre-exposure prophylaxis (PrEP) is an effective tool for preventing HIV infection among men who have sex with men (MSM), but its cost-effectiveness has varied across settings. Using an agent-based model, we projected the cost-effectiveness of a statewide PrEP program for MSM in Rhode Island over the next decade. In the absence of PrEP, the model predicted an average of 830 new HIV infections over ten years. Scaling up the existing PrEP program to cover 15% of MSM with ten or more partners each year could reduce the number of new HIV infections by 33.1% at a cost of $184,234 per quality-adjusted life-year (QALY) gained. Expanded PrEP use among MSM at high risk for HIV infection has the potential to prevent a large number of new HIV infections but the high drug-related costs may limit the cost-effectiveness of this intervention.

Acceptability and Barriers to HIV Pre-Exposure Prophylaxis in Atlanta's Adolescents and Their Parents

Adolescents aged 13-24 years account for 23% of new HIV infections in Atlanta, indicating need for better HIV prevention strategies in this population. Pre-exposure prophylaxis (PrEP) is now approved for adolescent use. This study aims to understand the acceptability of and barriers to PrEP in adolescents and parents. We administered PrEP acceptability and barrier measures to HIV(-) 13-17 year olds and their parents from January to April 2016 in an adolescent clinic and emergency department in Atlanta, GA, stratifying by adolescent sexual activity. Acceptability scores (AS) and barrier scores (BS) were calculated by averaging survey answers 1-3. For AS, 1 was very unlikely to accept PrEP; concomitantly, BS near 3 indicated fewer barriers. Two-sample hypothesis testing, Pearson correlations, and linear regression were used. Of the 102 adolescent/parent dyads, 67% of adolescents were female, 94% black, with a mean age of 15.7 ± 1.5 years, and 31% were sexually active. Parents were 94% female, 96% black, with a mean age of 42.4 ± 8.9 years. AS averaged between somewhat to very likely to accept PrEP (2.4 ± 0.5 and 2.2 ± 0.6) in adolescents and parents, respectively. BS averaged between unlikely and somewhat likely to perceive barriers to PrEP (2.0 ± 0.4 and 1.9 ± 0.5) in adolescents and parents, respectively. The adolescent/parent dyad is likely to accept PrEP, regardless of sexual activity. Limitations include that nearly 70% of adolescents were not sexually active, and the study was conducted before PrEP approval by the Food and Drug Administration for those who are younger than 18 years. These results support future parent and adolescent education on PrEP.

Sexually transmissible infection control programs for men who have sex with men - what will they look like in 2020?

The resurgence of sexually transmissible infections among men who have sex with men is a concern for sexual health. Traditional strategies have relied on the promotion of condom use, regular testing, treatment, and partner management. Future sexually transmissible infection control programs must combine current prevention methods with novel approaches that target the providers, patients, and mechanisms of health care delivery.

Drug resistance among patients who acquired HIV infection in a preexposure prophylaxis trial

BACKGROUND

The IPERGAY ANRS trial showed that on-demand preexposure prophylaxis (PrEP) with tenofovir (TDF) and emtricitabine (FTC) was highly effective in preventing HIV infection among highly exposed MSM. Here, we analyzed drug resistance-associated mutations (RAMs) among all participants who acquired HIV infection during this trial.

METHODS

Resistance was analyzed on frozen plasma at the time of HIV diagnosis among participants enrolled in the double-blind and open-label phases of the ANRS IPERGAY trial. Reverse transcriptase sequencing was performed, using population-based and ultradeep sequencing (454 GS Flex). Adherence was measured by pill counting and by plasma tenofovir and FTC assay.

RESULTS

During the trial, 31 participants were diagnosed with HIV-1 infection (subtype B, 64.5%), using antigen/antibody immune assay in 29 cases and plasma HIV RNA assay in two. The median plasma HIV-1 RNA level was 5.52 log10 copies/ml. Drug resistance was tested in 12 participants before starting PrEP, in six assigned to TDF/FTC group and in 13 assigned to placebo group. Primary resistance to nucleoside reverse transcriptase inhibitors (zidovudine) and/or nonnucleoside reverse transcriptase inhibitors was detected in six participants (19%; 95% confidence interval 7-42). No major or minor TDF-resistant or FTC-resistant variants were detected.

CONCLUSION

No TDF or FTC resistance-associated mutations were found among participants who acquired HIV in the ANRS IPERGAY trial.

Awareness and Acceptance of HIV Pre-exposure Prophylaxis among Medical Personnel and Men Who Have Sex with Men in Korea

BACKGROUND

We aimed to investigate the awareness of human immunodeficiency virus (HIV) infection among high-risk individuals, including men who have sex with men (MSM) and medical personnel (MP) in Korea through a cross-sectional survey, identify possible obstacles hindering their access to pre-exposure prophylaxis (PrEP).

METHODS

In 2016, the first questionnaire survey was sent to randomly selected MSM and MP. To compare the changes in attitudes and knowledge of MSM, a second questionnaire survey was conducted in August 2017.

RESULTS

More than half of MSM (61.3% in 2016, 88.6% in 2017) were aware of PrEP. However, MP who offered PrEP had less knowledge regarding PrEP (23.4%). The background knowledge and experience with PrEP among MSM and MP in this survey was low (3.4% in 2016 and 5.7% in 2017, 1.9% in MP). The major obstacles that MSM reported were lack of insurance coverage (29% in 2016 and 32% in 2017), concern regarding adverse effects of PrEP (19% and 21%), and risk of exposing HIV-positive status to other people (15% and 18%). Among MP, lack of knowledge regarding the efficacy of PrEP was the most common obstacle (30%), followed by lack of insurance coverage (22%), and concern regarding adverse effects (20%).

CONCLUSION

Our study showed that PrEP is required among MSM in Korea; however, most MP were not aware of PrEP. Lack of insurance coverage and knowledge regarding PrEP were major hindrances in the access to PrEP; therefore, further studies on how to make PrEP information more accessible are needed to help prevent HIV infection.

Is pre-exposure prophylaxis effective for preventing HIV infection in men who have sex with men?

INTRODUCTION

Increasing rates of HIV infection remain of concern, especially for high-risk groups such as men who have sex with men. Oral pre-exposure prophylaxis has emerged as an alternative to prevention. However, doubts persist in patients and physicians about its effectiveness.

METHODS

To answer this question we used Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach.

RESULTS AND CONCLUSIONS

We identified six systematic reviews including twelve studies overall, of which six were randomized trials. We concluded the use of oral pre-exposure prophylaxis reduces the probability of HIV infection in men who have sex with men, has few or no adverse effects, and is a measure with a good balance between benefits, risks and costs.

Facilitators and Barriers to Pre-Exposure Prophylaxis Willingness Among Young Men Who Have Sex with Men Who Use Geosocial Networking Applications in California

While correlates of pre-exposure prophylaxis (PrEP) uptake have been explored among older men who have sex with men (MSM), less is known about the facilitators and barriers that encourage uptake among younger MSM (YMSM). This study explores the association between willingness to take PrEP and demographic characteristics, sexual risk, and substance use, and attitudinal factors among YMSM in California who use geosocial networking applications (GSN apps). Based on survey data from YMSM recruited through GSN apps (n = 687), PrEP willingness was positively associated with Hispanic ethnicity [adjusted odds ratio (aOR): 1.73; confidence interval (CI): 1.01-2.98; p = 0.046], concerns about drug effects (aOR: 0.46; CI: 0.33-0.65; p < 0.001), medical mistrust (aOR: 0.71; CI: 0.53-0.96; p < 0.001), and concerns about adherence (aOR: 0.65; CI: 0.49-0.89; p = 0.005). PrEP willingness was positively associated with medium (aOR: 1.87; CI: 1.14-3.07; p = 0.014) and high concern (aOR: 1.84; CI: 1.13-3.01; p < 0.001) about contracting HIV and perceived benefits of taking PrEP (aOR: 2.59; CI: 1.78-3.78; p < 0.001). In addition to emphasizing the benefits of using PrEP, campaigns that address concerns regarding adherence and side effects may increase interest in and demand for PrEP among YMSM. More opportunities are needed to educate YMSM about PrEP, including addressing their concerns about this new prevention strategy. Providers should speak openly and honestly to YMSM considering PrEP about what to do if side effects occur and how to handle missed doses. Outreach using GSN apps for PrEP education and screening may be an effective way to reach YMSM.

Clinical and public health implications of acute and early HIV detection and treatment: a scoping review

INTRODUCTION

The unchanged global HIV incidence may be related to ignoring acute HIV infection (AHI). This scoping review examines diagnostic, clinical, and public health implications of identifying and treating persons with AHI.

METHODS

We searched PubMed, in addition to hand-review of key journals identifying research pertaining to AHI detection and treatment. We focused on the relative contribution of AHI to transmission and the diagnostic, clinical, and public health implications. We prioritized research from low- and middle-income countries (LMICs) published in the last fifteen years.

RESULTS AND DISCUSSION

Extensive AHI research and limited routine AHI detection and treatment have begun in LMIC. Diagnostic challenges include ease-of-use, suitability for application and distribution in LMIC, and throughput for high-volume testing. Risk score algorithms have been used in LMIC to screen for AHI among individuals with behavioural and clinical characteristics more often associated with AHI. However, algorithms have not been implemented outside research settings. From a clinical perspective, there are substantial immunological and virological benefits to identifying and treating persons with AHI - evading the irreversible damage to host immune systems and seeding of viral reservoirs that occurs during untreated acute infection. The therapeutic benefits require rapid initiation of antiretrovirals, a logistical challenge in the absence of point-of-care testing. From a public health perspective, AHI diagnosis and treatment is critical to: decrease transmission via viral load reduction and behavioural interventions; improve pre-exposure prophylaxis outcomes by avoiding treatment initiation for HIV-seronegative persons with AHI; and, enhance partner services via notification for persons recently exposed or likely transmitting.

CONCLUSIONS

There are undeniable clinical and public health benefits to AHI detection and treatment, but also substantial diagnostic and logistical barriers to implementation and scale-up. Effective early ART initiation may be critical for HIV eradication efforts, but widespread use in LMIC requires simple and accurate diagnostic tools. Implementation research is critical to facilitate sustainable integration of AHI detection and treatment into existing health systems and will be essential for prospective evaluation of testing algorithms, point-of-care diagnostics, and efficacious and effective first-line regimens.

Transmitted drug resistance in patients with acute/recent HIV infection in Brazil

Introduction

The widespread use of antiretroviral therapy increased the transmission of antiretroviral resistant HIV strains. Antiretroviral therapy initiation during acute/recent HIV infection limits HIV reservoirs and improves immune response in HIV infected individuals. Transmitted drug resistance may jeopardize the early goals of early antiretroviral treatment among acute/recent HIV infected patients.

Methods

Patients with acute/recent HIV infection who underwent resistance test before antiretroviral treatment initiation were included in this analysis. HIV-1 sequences were obtained using an in house protease/reverse transcriptase genotyping assay. Transmitted drug resistance was identified according to the Stanford HIV Database for Transmitted Drug Resistance Mutations, based on WHO 2009 surveillance list, and HIV-1 subtyping according to Rega HIV-1 subtyping tool. Comparison between patients with and without transmitted drug resistance was made using Kruskal–Wallis and Chi-square tests.

Results

Forty-three patients were included, 13 with acute HIV infection and 30 with recent HIV infection. The overall transmitted drug resistance prevalence was 16.3% (95% confidence interval [CI]: 8.1–30.0%). The highest prevalence of resistance (11.6%, 95% CI: 8.1–24.5) was against non-nucleoside reverse transcriptase inhibitors, and K103N was the most frequently identified mutation.

Conclusions

The high prevalence of nonnucleoside reverse transcriptase inhibitors resistance indicates that efavirenz-based regimen without prior resistance testing is not ideal for acutely/recently HIV-infected individuals in our setting. In this context, the recent proposal of including integrase inhibitors as a first line regimen in Brazil could be an advantage for the treatment of newly HIV infected individuals. However, it also poses a new challenge, since integrase resistance test is not routinely performed for antiretroviral naive individuals. Further studies on transmitted drug resistance among acutely/recently HIV-infected are needed to inform the predictors of transmitted resistance and the antiretroviral therapy outcomes among these population.

Awareness and attitudes of pre-exposure prophylaxis for HIV prevention among physicians in Guatemala: Implications for country-wide implementation

INTRODUCTION

HIV continues to be a major health concern with approximately 2.1 million new infections occurring worldwide in 2015. In Central America, Guatemala had the highest incident number of HIV infections (3,700) in 2015. Antiretroviral pre-exposure prophylaxis (PrEP) was recently recommended by the World Health Organization (WHO) as an efficacious intervention to prevent HIV transmission. PrEP implementation efforts are underway in Guatemala and success will require providers that are knowledgeable and willing to prescribe PrEP. We sought to explore current PrEP awareness and prescribing attitudes among Guatemalan physicians in order to inform future PrEP implementation efforts.

METHODS

We conducted a cross-sectional survey of adult internal medicine physicians at the main teaching hospital in Guatemala City in March 2015. The survey included demographics, medical specialty, years of HIV patient care, PrEP awareness, willingness to prescribe PrEP, previous experience with post-exposure prophylaxis, and concerns about PrEP. The primary outcome was willingness to prescribe PrEP, which was assessed using a 5-point Likert scale for different at-risk population scenarios. Univariate and multivariate logistic regression was performed to identify predictors for willingness to prescribe PrEP.

RESULTS

Eighty-seven physicians completed the survey; 66% were male, 64% were internal medicine residency trainees, and 10% were infectious disease (ID) specialists. Sixty-nine percent of physicians were PrEP aware, of which 9% had previously prescribed PrEP. Most (87%) of respondents were willing to prescribe PrEP to men who have sex with men (MSM), sex workers, injection drug users, or HIV-uninfected persons having known HIV-positive sexual partners. Concerns regarding PrEP included development of resistance (92%), risk compensation (90%), and cost (64%). Univariate logistic regression showed that younger age, being a resident trainee, and being a non-ID specialist were significant predictors for willingness to prescribe PrEP. In multivariate logistic regression, being a non-ID specialist was a significant predictor.

CONCLUSIONS

Guatemalan physicians at an urban public hospital were PrEP aware and willing to prescribe, but few have actually done so yet. Future education programs should address the concerns identified, including the low potential for the development of antiretroviral resistance. These findings can aid PrEP implementation efforts in Guatemala.

Successful Implementation of HIV Preexposure Prophylaxis: Lessons Learned From Three Clinical Settings

The past 3 years have marked a transition from research establishing the safety and efficacy of HIV preexposure prophylaxis (PrEP) to questions about how to optimize its implementation. Until recently, PrEP was primarily offered as part of randomized controlled trials or open-label studies. These studies highlighted the key components of PrEP delivery, including regular testing for HIV and other sexually transmitted infections (STIs), adherence and risk-reduction support, and monitoring for renal toxicity. PrEP is now increasingly provided in routine clinical settings. This review summarizes models for PrEP implementation from screening through initiation and follow-up, focusing on the strengths and weaknesses of three delivery systems: a health maintenance organization, an STI clinic, and a primary care practice. These early implementation experiences demonstrate that PrEP can be successfully delivered across a variety of settings and highlight strategies to streamline PrEP delivery in clinical practice.

What does preexposure prophylaxis mean for treatment; what does treatment mean for preexposure prophylaxis?

PURPOSE OF REVIEW

Both preexposure prophylaxis (PrEP) and treatment as prevention (TaP) have shown promise in contributing to HIV prevention, in models, observational cohorts and in real-world intervention studies. They share similarities, in that they use the same drugs, toxicity markers and may be focused on the same key populations. How to implement PrEP is still the source of much debate; effective coverage with TaP, with recent data on the positive impact of treatment at high CD4 counts, is still an ongoing challenge.

RECENT FINDINGS

Treatment has demonstrated individual benefit even at CD4 counts above 350 cells/μl; PrEP has shown the effectiveness in real-world use.

SUMMARY

This article discusses the intersection of the two interventions, some programmatic misconceptions and complexities, and argues that PrEP is a nuanced and useful adjunct to HIV programmes. PrEP can be rolled out in a way that complements treatment, possibly even within primary health clinics, and may be required for the many people in whom TaP currently fails. PrEP will need constant adaptation so as to maintain programmatic and cost-effectiveness, as the epidemiology of HIV changes with TaP rollout and expansion as CD4 restrictions are lifted. Finally, the article also argues that so-called ethical concerns around competing resources are relatively easily resolved.

Should we fear resistance from tenofovir/emtricitabine preexposure prophylaxis?

PURPOSE OF REVIEW

To review current data on HIV-1 resistance arising from the use of fixed dose combination tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) for preexposure prophylaxis (PrEP) to prevent HIV-1 infection.

RECENT FINDINGS

Resistance to tenofovir (TNV) or FTC is infrequently selected by TDF/FTC PrEP if started before HIV-1 infection has occurred, but is much more common when inadvertently started during undiagnosed acute infection. Mathematical modeling predicts that the number of HIV-1 infections averted by the use of PrEP far exceeds the increase in drug-resistant infections that could occur from PrEP. Studies in macaques show that TNV-resistant virus but not FTC-resistant virus can cause breakthrough infection despite TDF/FTC PrEP. FTC resistance with M184 V/I occurs more frequently than TFV resistance with K65R in seroconverters from clinical trials of TDF/FTC PrEP.

SUMMARY

The benefit of preventing HIV-1 infections with TDF/FTC PrEP far outweighs the risk of drug-resistant infection, provided PrEP is not started in persons with undiagnosed HIV-1 infection. We should respect but not fear HIV-1 resistance from TDF/FTC PrEP and recognize that most TNV or FTC resistance will arise from its use for antiretroviral therapy (ART). Preventing ART failure or detecting it early is most important for preventing the spread of HIV-1 resistance to TDF/FTC and preserving its effectiveness for both PrEP and ART.

Transmitted HIV Drug Resistance Is High and Longstanding in Metropolitan Washington, DC

BACKGROUND

Washington, DC, has 2.5% human immunodeficiency virus (HIV) prevalence, 3.9% among African Americans. Antiretrovirals (ARTs) are the cornerstone for treatment and prevention. Monitoring changes in transmitted drug resistance (TDR) is critical for effective HIV care.

METHODS

HIV genotype data for individuals enrolled in research studies in metropolitan Washington, D.C., were used to identify TDR using the World Health Organization mutation list [Bennett DE, Camacho RJ, Otelea D, et al. Drug resistance mutations for surveillance of transmitted HIV-1 drug-resistance: 2009 update. PloS One 2009; 4:e4724]. HIV phylogenies were reconstructed using maximum likelihood and Bayesian methods. HIV transmission clusters were supported by 1000 bootstrap values >0.70 and posterior probability >0.95 of having a common ancestor.

RESULTS

Among 710 individuals enrolled in 1994-2013, the median age was 38.6 years, 46.2% were female, and 53.3% were African-American. TDR was 22.5% among 566 treatment-naive individuals; 15.8% had nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) resistance, 9.8% had nonnucleoside reverse-transcriptase inhibitor (NNRTI) resistance, and 4.2% had protease inhibitor (PI) resistance. Single class TDR was 10.0%, 5.1%, and 1.6% to NRTIs, NNRTIs, and PIs. Dual TDR to PI and NRTI was seen in 1.6%, NRTI and NNRTI in 3.4%, and triple class TDR in 0.9%. TDR frequency decreased from 1994-2006 (27.1%) to 2007-2013 (19.4%; P = .02). Only 6/79 (7.6%) individuals within transmission clusters had evidence of TDR.

DISCUSSIONS

We identified high prevalence of TDR among HIV-infected individuals in metropolitan Washington, DC, regardless of gender. Active surveillance for TDR is needed to guide ART usage and analyses of risk group contributions to HIV transmission and resistance.

Pre-exposure prophylaxis: a useful tool to prevent human immunodeficiency virus infection?

The aim of preventive measures against human immunodeficiency virus (HIV) is to reduce the incidence of HIV infection in the general population and in high-risk groups, such as men having sex with men (MSM), and to reduce the risk that a given individual will contract or spread the virus. Male and female condoms, post-exposure prophylaxis and circumcision are preventive methods currently recognized or promoted worldwide. Although modest success has been reported in a phase-III vaccine trial, other methods are being evaluated, such as vaginal and rectal microbicides, and pre-exposure prophylaxis (PrEP). Herein, we discuss results from prevention trials, especially those focusing on PrEP and particularly on recent results from 'on-demand' PrEP regimens. The efficacy of PrEP (rates of 0%-86%) is strongly correlated with adherence and plasma concentrations of antiretrovirals. Adverse events are rare. Selection of emtricitabine-resistant strains is mainly reported in individuals with an undiagnosed HIV infection using PrEP. PrEP is now strongly recommended in WHO prevention programmes for individuals at substantial risk for HIV with a view to controlling this epidemic by 2030.

HIV-1 drug resistance and resistance testing

The global scale-up of antiretroviral (ARV) therapy (ART) has led to dramatic reductions in HIV-1 mortality and incidence. However, HIV drug resistance (HIVDR) poses a potential threat to the long-term success of ART and is emerging as a threat to the elimination of AIDS as a public health problem by 2030. In this review we describe the genetic mechanisms, epidemiology, and management of HIVDR at both individual and population levels across diverse economic and geographic settings. To describe the genetic mechanisms of HIVDR, we review the genetic barriers to resistance for the most commonly used ARVs and describe the extent of cross-resistance between them. To describe the epidemiology of HIVDR, we summarize the prevalence and patterns of transmitted drug resistance (TDR) and acquired drug resistance (ADR) in both high-income and low- and middle-income countries (LMICs). We also review to two categories of HIVDR with important public health relevance: (i) pre-treatment drug resistance (PDR), a World Health Organization-recommended HIVDR surveillance metric and (ii) and pre-exposure prophylaxis (PrEP)-related drug resistance, a type of ADR that can impact clinical outcomes if present at the time of treatment initiation. To summarize the implications of HIVDR for patient management, we review the role of genotypic resistance testing and treatment practices in both high-income and LMIC settings. In high-income countries where drug resistance testing is part of routine care, such an understanding can help clinicians prevent virological failure and accumulation of further HIVDR on an individual level by selecting the most efficacious regimens for their patients. Although there is reduced access to diagnostic testing and to many ARVs in LMIC, understanding the scientific basis and clinical implications of HIVDR is useful in all regions in order to shape appropriate surveillance, inform treatment algorithms, and manage difficult cases.

Impact of circulating resistance-associated mutations on HIV pre-exposure prophylaxis (PrEP) efficacy: Modeling from antiretroviral resistance cohort analysis (ARCA) national database

BACKGROUND

PrEP with FTC/TDF has shown great efficacy in preventing new HIV infections but issues remain (low adherence, high costs, toxicity and resistance development). No data are available about the impact of circulating Resistance-Associated Mutations (RAMs) on its efficacy.

OBJECTIVES

describe the prevalence of FTC and/or TDF-related RAMs in Italian HIV-infected population and their potential impact on PrEP efficacy.

STUDY DESIGN

ARCA is a national database that collects data about RAMs and epidemiological correlates from sites throughout Italy; it was queried about the prevalence of these RAMs in the last decade. PrEP efficacy was adjusted for a dynamic score based on RAMs prevalence. Absolute and relative risk increases (ARI and RRI) and number needed to harm (NNH) were calculated after this score.

RESULTS

the query retrieved 3579 HAART-naïve and 5781 experienced subjects. Resistance to TDF is low and more common among naïve MSM in the area of Milan (where it topped to 14.3%), without other significant differences. If good adherence is not attained, RRI for receptive anal sex increases by 16% (in naïve) and 93.4% (in experienced MSM). NNH is largely above 10000 except for having receptive anal sex with a HAART-experienced MSM on a failing treatment (970).

CONCLUSIONS

according to this model, PrEP may be introduced in Italy without general concerns, but efficacy may be partly reduced in young MSM having sex in Rome and Milan.

Effectiveness and safety of oral HIV preexposure prophylaxis for all populations

OBJECTIVE

Preexposure prophylaxis (PrEP) offers a promising new approach to HIV prevention. This systematic review and meta-analysis evaluated the evidence for use of oral PrEP containing tenofovir disoproxil fumarate as an additional HIV prevention strategy in populations at substantial risk for HIV based on HIV acquisition, adverse events, drug resistance, sexual behavior, and reproductive health outcomes.

DESIGN

Rigorous systematic review and meta-analysis.

METHODS

A comprehensive search strategy reviewed three electronic databases and conference abstracts through April 2015. Pooled effect estimates were calculated using random-effects meta-analysis.

RESULTS

Eighteen studies were included, comprising data from 39 articles and six conference abstracts. Across populations and PrEP regimens, PrEP significantly reduced the risk of HIV acquisition compared with placebo. Trials with PrEP use more than 70% demonstrated the highest PrEP effectiveness (risk ratio = 0.30, 95% confidence interval: 0.21-0.45, P < 0.001) compared with placebo. Trials with low PrEP use did not show a significantly protective effect. Adverse events were similar between PrEP and placebo groups. More cases of drug-resistant HIV infection were found among PrEP users who initiated PrEP while acutely HIV-infected, but incidence of acquiring drug-resistant HIV during PrEP use was low. Studies consistently found no association between PrEP use and changes in sexual risk behavior. PrEP was not associated with increased pregnancy-related adverse events or hormonal contraception effectiveness.

CONCLUSION

PrEP is protective against HIV infection across populations, presents few significant safety risks, and there is no evidence of behavioral risk compensation. The effective and cost-effective use of PrEP will require development of best practices for fostering uptake and adherence among people at substantial HIV risk.

Long-term follow-up of HIV seroconverters in microbicide trials - rationale, study design, and challenges in MTN-015

BACKGROUND

As the effect of biomedical prevention interventions on the natural history of HIV-1 infection in participants who seroconvert is unknown, the Microbicide Trials Network (MTN) established a longitudinal study (MTN-015) to monitor virologic, immunological, and clinical outcomes, as well as behavioral changes among women who become HIV-infected during MTN trials. We describe the rationale, study design, implementation, and enrollment of the initial group of participants in the MTN seroconverter cohort.

METHODS

Initiated in 2008, MTN-015 is an ongoing observational cohort study enrolling participants who acquire HIV-1 infection during effectiveness studies of candidate microbicides. Eligible participants from recently completed and ongoing MTN trials are enrolled after seroconversion and return for regular follow-up visits with clinical and behavioral data collection. Biologic samples including blood and genital fluids are stored for future testing.

RESULTS

MTN-015 was implemented initially at six African sites and enrolled 100/139 (72%) of eligible women who seroconverted in HIV Prevention Trials Network protocol 035 (HPTN 035, conducted by the MTN). The median time from seroconversion in HPTN 035 to enrollment in MTN-015 was 18 months. Retention was good with >70% of visits completed. Implementation challenges included regulatory reviews, translation, and testing of questionnaires, and site readiness.

CONCLUSIONS

Enrollment of HIV-seroconverters into a longitudinal observational follow-up study is feasible and acceptable to participants. Data and samples collected in this protocol will be used to assess safety of investigational HIV microbicides and answer other important public health questions for HIV infected women.

How Much Do We Know about Drug Resistance Due to PrEP Use? Analysis of Experts' Opinion and Its Influence on the Projected Public Health Impact

BACKGROUND

Randomized controlled trials reported that pre-exposure prophylaxis (PrEP) with tenofovir and emtricitabine rarely selects for drug resistance. However, drug resistance due to PrEP is not completely understood. In daily practice, PrEP will not be used under the well-controlled conditions available in the trials, suggesting that widespread use of PrEP can result in increased drug resistance.

METHODS

We surveyed expert virologists with questions about biological assumptions regarding drug resistance due to PrEP use. The influence of these assumptions on the prevalence of drug resistance and the fraction of HIV transmitted resistance was studied with a mathematical model. For comparability, 50% PrEP-coverage of and 90% per-act efficacy of PrEP in preventing HIV acquisition are assumed in all simulations.

RESULTS

Virologists disagreed on the following: the time until resistance emergence (range: 20-180 days) in infected PrEP users with breakthrough HIV infections; the efficacy of PrEP against drug-resistant HIV (25%-90%); and the likelihood of resistance acquisition upon transmission (10%-75%). These differences translate into projections of 0.6%- 1% and 3.5%-6% infected individuals with detectable resistance 10 years after introducing PrEP, assuming 100% and 50% adherence, respectively. The rate of resistance emergence following breakthrough HIV infection and the rate of resistance reversion after PrEP use is discontinued, were the factors identified as most influential on the expected resistance associated with PrEP. Importantly, 17-23% infected individuals could virologically fail treatment as a result of past PrEP use or transmitted resistance to PrEP with moderate adherence.

CONCLUSIONS

There is no broad consensus on quantification of key biological processes that underpin the emergence of PrEP-associated drug resistance. Despite this, the contribution of PrEP use to the prevalence of the detectable drug resistance is expected to be small. However, individuals who become infected despite the use of PrEP should be closely monitored due to higher risk of virological failure when initiating antiretroviral treatment in the future.

Antiretroviral Therapy for Prevention of Human Immunodeficiency Virus Infection

Human immunodeficiency virus (HIV) infection is considered a chronic medical condition. Several new drugs are available, including fixed-dose combination tablets, that have greatly simplified combination antiretroviral therapy (ART) regimens to treat HIV, while increasing the life-expectancy of infected individuals. In the last decade, multiple well-regarded studies have established the benefits of using ART in high-risk, HIV-negative persons to prevent HIV acquisition. The primary care provider must not only understand commonly encountered issues pertaining to ART, such as toxicities and drug interactions, but also needs to be aware of using ART for HIV prevention.

Adherence to Pre-Exposure Prophylaxis for HIV Prevention in a Clinical Setting

Background

The HIV epidemic in the United States (US) disproportionately affects gay, bisexual, and other men who have sex with men (MSM). Pre-exposure prophylaxis (PrEP) using co-formulated tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) has demonstrated high efficacy in reducing HIV incidence among MSM. However, low adherence was reported in major efficacy trials and may present a substantial barrier to successful PrEP implementation. Rates of adherence to PrEP in “real-world” clinical settings in the US remain largely unknown.

Methods

We reviewed demographic and clinical data for the first 50 patients to enroll in a clinical PrEP program in Providence, Rhode Island. We analyzed self-reported drug adherence as well as drug concentrations in dried blood spots (DBS) from patients who attended either a three- or six-month follow-up appointment. We further assessed drug concentrations and the resistance profile of a single patient who seroconverted while taking PrEP.

Results

Of the first 50 patients to be prescribed PrEP, 62% attended a follow-up appointment at three months and 38% at six months. Of those who attended an appointment at either time point (70%, n = 35), 92% and 95% reported taking ±4 doses/week at three and six months, respectively. Drug concentrations were performed on a random sample of 20 of the 35 patients who attended a follow-up appointment. TDF levels consistent with ±4 doses/week were found in 90% of these patients. There was a significant correlation between self-reported adherence and drug concentrations (r = 0.49, p = 0.02). One patient who had been prescribed PrEP seroconverted at his three-month follow-up visit. The patient’s drug concentrations were consistent with daily dosing. Population sequencing and ultrasensitive allele-specific PCR detected the M184V mutation, but no other TDF- or FTC-associated mutations, including those present as minor variants.

Conclusion

In this clinical PrEP program, adherence was high, and self-reported drug adherence accurately reflected drug concentrations as measured by DBS.

Understanding HIV Care Provider Attitudes Regarding Intentions to Prescribe PrEP

INTRODUCTION

Preexposure prophylaxis (PrEP) is a promising approach to reducing HIV incidence. So, garnering the support of HIV providers, who are most familiar with antiretrovirals and likely to encounter patients in HIV serodiscordant relationships, to scale-up PrEP implementation is essential. We sought to determine whether certain subgroups of HIV providers were more likely to intend to prescribe PrEP.

METHODS

Surveys were administered to HIV providers in Miami, Florida and Washington, District of Columbia. Composite scores were developed to measure PrEP knowledge, experience, and likelihood of prescribing. Latent class analysis was used to stratify provider attitudes toward PrEP.

RESULTS

Among 142 HIV providers, 73.2% had cared for more than 20 HIV-infected patients in the previous 3 months; 17% had ever prescribed PrEP. Latent class analysis identified 2 classes of providers (entropy, 0.904); class 1 (n = 95) found PrEP less effective and perceived barriers to prescribing it; class 2 (n = 47) perceived PrEP as moderately effective and perceived fewer barriers to prescribing it. Compared with class 2, class 1 had significantly less experience with PrEP delivery (t(22.7) = 2.88, P = 0.009) and was significantly less likely to intend to prescribe to patients with multiple sex partners (20% vs. 43%, P = 0.04) and those with a drug use history (7% vs. 24%, P = 0.001).

CONCLUSIONS

Although most HIV providers found PrEP to be effective, those considering it less effective had limited knowledge and experience with PrEP and had lesser intentions to prescribe. Provider training regarding whom should receive PrEP and addressing potential barriers to PrEP provision are needed if this HIV prevention method is to be optimized.

The Transition From Postexposure Prophylaxis to Preexposure Prophylaxis: An Emerging Opportunity for Biobehavioral HIV Prevention

Although some individuals who present for antiretroviral postexposure prophylaxis (PEP) had a 1-time exposure to human immunodeficiency virus (HIV), others may be recurrently risky. Given that preexposure prophylaxis (PrEP) has been shown to be efficacious, identification of those individuals who present for PEP who might benefit from PrEP is important to decrease HIV acquisition in high-risk individuals. While inclusion criteria for PrEP have been developed, there is a paucity of data to help clinicians determine which PEP users are at highest risk for HIV acquisition and therefore should be offered PrEP. We will discuss the rationale for using PrEP after PEP use, and will focus on the assessment of PEP users who may benefit from PrEP.

Antiretrovirals for primary HIV prevention: the current status of pre- and post-exposure prophylaxis

In light of the 2 million HIV infections that occur globally each year, there is a need to optimize strategies that integrate biomedical and behavioral approaches to HIV prevention. Post-exposure prophylaxis (PEP) immediately after acute high-risk exposures and pre-exposure prophylaxis (PrEP) for those who engage in recurrent high-risk behaviors are promising bio-behavioral approaches to decreasing HIV transmission. Guidelines have recommended PEP for occupational and non-occupational exposures for over 15 years, but uptake of PEP has been limited, partly as a result of insufficient awareness of this intervention among persons at highest risk for acquiring HIV. However, since the publication of large randomized clinical trials demonstrating the efficacy of PrEP, and the dissemination of guidelines endorsing its use, there is a renewed focus on bio-behavioral prevention. Numerous studies have recently assessed the acceptability of bio-behavioral prevention programs among diverse populations or described experiences implementing these programs in "real-world" settings. As research and clinical data informing optimal utilization of PEP and PrEP are rapidly accumulating, this review provides a timely summary of recent progress in bio-behavioral prevention. By contextualizing the most noteworthy recent findings regarding PEP and PrEP, this review seeks to inform the successful implementation of these promising prevention approaches.

Performance of Determine Combo and other point-of-care HIV tests among Seattle MSM

BACKGROUND AND OBJECTIVE

The rapid test study was a real-time comparison of point-of-care (POC) HIV tests to determine their abilities to detect early HIV infection.

STUDY DESIGN

Men and transgender persons reporting sex with men in the prior year were recruited at the Public Health-Seattle & King County STD Clinic, Gay City Health Project, and University of Washington Primary Infection Clinic. Study tests included the OraQuick ADVANCE Rapid HIV-1/2 Antibody Test performed on oral fluids and tests performed on fingerstick whole blood specimens including OraQuick, Uni-Gold Recombigen HIV test, Determine HIV-1/2 Ag/Ab Combo, and INSTI HIV-1 Rapid Antibody Test. Specimens from subjects with negative results were sent for EIA and nucleic acid amplification testing. McNemar's exact tests compared the numbers of HIV-infected subjects detected.

RESULTS

Between February 2010 and August 2014, there were 3438 study visits. Twenty-four subjects had discordant POC results with at least one reactive and one non-reactive test, including one subject with a reactive Determine p24 antigen. OraQuick performed on oral fluids identified fewer persons compared to all fingerstick tests. OraQuick performed on fingerstick whole blood detected fewer persons compared to the Determine Combo antibody component (p=.008) and Combo overall (p=.004), and there was a trend when compared to INSTI (p=.06). The Determine Combo specificity was 98.99%.

CONCLUSIONS

As reported by others, Determine Combo underperforms compared to laboratory-based testing, but it did detect one acute infection. If these results are validated, the specificity of Determine Combo may limit its usefulness in populations with lower HIV incidence.

Preexposure prophylaxis-selected drug resistance decays rapidly after drug cessation

OBJECTIVE

Resistance to emtricitabine plus tenofovir disoproxil fumarate (FTC/TDF) or TDF alone used as preexposure prophylaxis (PrEP) has been detected in individuals who initiated PrEP during unrecognized acute HIV infection and, rarely, in PrEP breakthrough infections. PrEP-selected resistance could alter future treatment options, and therefore we sought to determine how long resistance persisted after PrEP cessation.

METHODS

The Partners PrEP Study was a randomized placebo-controlled trial of FTC/TDF or TDF as PrEP for HIV prevention. We previously reported that PrEP-related mutations (K65R, K70E or M184IV) were detected by 454 sequencing following seroconversion in nine individuals who acquired HIV during the Partners PrEP Study. In the current study, we used 454 sequencing to detect and quantify PrEP-related mutations in HIV RNA-positive plasma samples prior to seroconversion, as well as in plasma from 6, 12, and 24 months after PrEP cessation from these nine individuals.

RESULTS

HIV RNA-positive, antibody-negative samples were available prior to seroconversion for four of nine individuals with resistance detected at seroconversion. In all four cases, K65R, K70E and M184IV were not detected prior to seroconversion, suggesting PrEP-related resistance was selected and not transmitted. All PrEP-selected mutations were no longer detectable by 6 months after PrEP cessation and remained undetectable at 12 and 24 months in the absence of antiretroviral therapy.

CONCLUSION

Using highly sensitive assays, PrEP-selected resistance in plasma decays below detection by 6 months following drug cessation and remains undetectable for at least 24 months. Even high levels of resistance mutations during acute infection decay rapidly in the absence of ongoing PrEP exposure.

Preexposure Prophylaxis for HIV Infection Integrated With Municipal- and Community-Based Sexual Health Services

IMPORTANCE

Several randomized clinical trials have demonstrated the efficacy of preexposure prophylaxis (PrEP) in preventing human immunodeficiency virus (HIV) acquisition. Little is known about adherence to the regimen, sexual practices, and overall effectiveness when PrEP is implemented in clinics that treat sexually transmitted infections (STIs) and community-based clinics serving men who have sex with men (MSM).

OBJECTIVE

To assess PrEP adherence, sexual behaviors, and the incidence of STIs and HIV infection in a cohort of MSM and transgender women initiating PrEP in the United States.

DESIGN, SETTING, AND PARTICIPANTS

Demonstration project conducted from October 1, 2012, through February 10, 2015 (last date of follow-up), among 557 MSM and transgender women in 2 STI clinics in San Francisco, California, and Miami, Florida, and a community health center in Washington, DC. Data were analyzed from December 18, 2014, through August 8, 2015.

INTERVENTIONS

A combination of daily, oral tenofovir disoproxil fumarate and emtricitabine was provided free of charge for 48 weeks. All participants received HIV testing, brief client-centered counseling, and clinical monitoring.

MAIN OUTCOMES AND MEASURES

Concentrations of tenofovir diphosphate in dried blood spot samples, self-reported numbers of anal sex partners and episodes of condomless receptive anal sex, and incidence of STI and HIV acquisition.

RESULTS

Overall, 557 participants initiated PrEP, and 437 of these (78.5%) were retained through 48 weeks. Based on the findings from the 294 participants who underwent measurement of tenofovir diphosphate levels, 80.0% to 85.6% had protective levels (consistent with ≥4 doses/wk) at follow-up visits. African American participants (56.8% of visits; P = .003) and those from the Miami site (65.1% of visits; P < .001) were less likely to have protective levels, whereas those with stable housing (86.8%; P = .02) and those reporting at least 2 condomless anal sex partners in the past 3 months (88.6%; P = .01) were more likely to have protective levels. The mean number of anal sex partners declined during follow-up from 10.9 to 9.3, whereas the proportion engaging in condomless receptive anal sex remained stable at 65.5% to 65.6%. Overall STI incidence was high (90 per 100 person-years) but did not increase over time. Two individuals became HIV infected during follow-up (HIV incidence, 0.43 [95% CI, 0.05-1.54] infections per 100 person-years); both had tenofovir diphosphate levels consistent with fewer than 2 doses/wk at seroconversion.

CONCLUSIONS AND RELEVANCE

The incidence of HIV acquisition was extremely low despite a high incidence of STIs in a large US PrEP demonstration project. Adherence was higher among those participants who reported more risk behaviors. Interventions that address racial and geographic disparities and housing instability may increase the impact of PrEP.

Safety of oral tenofovir disoproxil fumarate-based pre-exposure prophylaxis for HIV prevention

INTRODUCTION

Tenofovir disoproxil fumarate (TDF)-based pre-exposure prophylaxis is a novel HIV prevention strategy for individuals at increased sexual risk for HIV infection. For any biomedical prevention intervention, the bar for tolerating adverse effects in healthy persons is high compared to therapeutic interventions.

AREAS COVERED

We provide a concise summary of the clinical safety of TDF-based pre-exposure prophylaxis with focus on TDF-related effects on tolerability, kidney function, bone density, HIV resistance, sexual and reproductive health. The evidence base for this review is derived from a literature search of both randomized and observational studies evaluating efficacy and safety of TDF-based PrEP, TDF alone or in combination with emtricitabine, identified from PUBMED and EMBASE electronic databases, clinicaltrials.gov and major HIV conferences.

EXPERT OPINION

TDF-based pre-exposure prophylaxis is a potent intervention against HIV acquisition when taken which is generally safe and well tolerated. The risk of the small, non-progressive, and reversible decline in glomerular filtration rate and bone mineral density as well as the potential selection for drug resistance associated with PrEP are outweighed, at the population level and broadly for individuals, by PrEP's substantial reduction in the risk of HIV infection.

Multiplexed highly-accurate DNA sequencing of closely-related HIV-1 variants using continuous long reads from single molecule, real-time sequencing

Single Molecule, Real-Time (SMRT) Sequencing (Pacific Biosciences, Menlo Park, CA, USA) provides the longest continuous DNA sequencing reads currently available. However, the relatively high error rate in the raw read data requires novel analysis methods to deconvolute sequences derived from complex samples. Here, we present a workflow of novel computer algorithms able to reconstruct viral variant genomes present in mixtures with an accuracy of >QV50. This approach relies exclusively on Continuous Long Reads (CLR), which are the raw reads generated during SMRT Sequencing. We successfully implement this workflow for simultaneous sequencing of mixtures containing up to forty different >9 kb HIV-1 full genomes. This was achieved using a single SMRT Cell for each mixture and desktop computing power. This novel approach opens the possibility of solving complex sequencing tasks that currently lack a solution.