Adherence to post-exposure prophylaxis for non-forcible sexual exposure to HIV: a systematic review and meta-analysis

A behavioral economics approach to enhancing HIV preexposure and postexposure prophylaxis implementation

PURPOSE OF REVIEW

The 'PrEP cliff' phenomenon poses a critical challenge in global HIV PrEP implementation, marked by significant dropouts across the entire PrEP care continuum. This article reviews new strategies to address 'PrEP cliff'.

RECENT FINDINGS

Canadian clinicians have developed a service delivery model that offers presumptive PEP to patients in need and transits eligible PEP users to PrEP. Early findings are promising. This service model not only establishes a safety net for those who were not protected by PrEP, but it also leverages the immediate salience and perceived benefits of PEP as a natural nudge towards PrEP use. Aligning with Behavioral Economics, specifically the Salience Theory, this strategy holds potential in tackling PrEP implementation challenges.

SUMMARY

A natural pathway between PEP and PrEP has been widely observed. The Canadian service model exemplifies an innovative strategy that leverages this organic pathway and enhances the utility of both PEP and PrEP services. We offer theoretical insights into the reasons behind these PEP-PrEP transitions and evolve the Canadian model into a cohesive framework for implementation.

Adherence, adverse drug reactions, and discontinuation associated with adverse drug reactions of HIV post-exposure prophylaxis: a meta-analysis based on cohort studies

Objective: Evaluate the profiles of post-exposure prophylaxis (PEP) adherence, adverse drug reactions (ADRs), and discontinuation associated with ADRs to provide information for further PEP program improvement and increase adherence to PEP.Methods: The Web of Science, PubMed, Embase, and the Cochrane Library were searched for cohort studies reporting data related to PEP adherence or ADRs (PROSPERO, CRD42022385073). Pooled estimates of adherence, the incidence of ADRs and discontinuation associated with ADRs, and their 95% confidence intervals (CI) were calculated separately for the included literature using random effects models. For substantial heterogeneity, meta-regression and subgroup analyses were conducted to explore sources of heterogeneity.Results: Overall adherence was 58.4% (95% CI: 50.9%-65.8%), with subgroup analysis showing differences in adherence across samples, with the highest adherence among men who had sex with men (MSM) (72.4%, 95% CI: 63.4%-81.3%) and the lowest adherence among survivors of sexual assault (SAs) (41.7%, 95% CI: 28.0%-55.3%). The incidence of ADRs was 60.3% (95% CI: 50.3%-70.3%), and the prevalence of PEP discontinuation associated with ADRs was 32.7% (95% CI: 23.7%-41.7%), with subgroup analyses revealing disparities in the prevalence of discontinuation associated with ADRs among samples with different drug regimens. Time trend analysis showed a slight downward trend in the incidence of ADRs and PEP discontinuation associated with ADRs.Conclusion: Adherence to PEP was less than 60% across samples, however, there was significant heterogeneity depending on the samples. SAs had the lowest adherence and the highest incidence of PEP discontinuation. Ongoing adherence education for participants, timely monitoring, and management of ADRs may improve adherence.

Trends of nonoccupational postexposure prophylaxis in the United States

OBJECTIVE

To describe national annual rates of nonoccupational postexposure prophylaxis (nPEP) in the United States.

DESIGN

Retrospective cohort study of commercially insured individuals in the Merative MarketScan Database from January 1, 2010 to December 31, 2019.

METHODS

Patients at least 13 years old prescribed nPEP per recommended Centers for Disease Control and Prevention guidelines were identified using pharmacy claims. Rates of use were described overall and stratified by sex, age group, and region. These rates were qualitatively compared to the diagnosis rates of human immunodeficiency virus (HIV) observed in the data. Joinpoint analysis identified inflection points of nPEP use.

RESULTS

Eleven thousand, three hundred and ninety-seven nPEP users were identified, with a mean age of 33.7 years. Most were males (64.6%) and lived in the south (33.2%) and northeast (32.4%). The rate of nPEP use increased 515%, from 1.42 nPEP users per 100 000 enrollees in 2010 to 8.71 nPEP users per 10 000 enrollees in 2019. The comparative nPEP use rates among subgroups largely mirrored their HIV diagnosis rates, that is, subgroups with a higher HIV rate had higher nPEP use. In the Joinpoint analysis significant growth was observed from 2012 to 2015 [estimated annual percentage change (EAPC): 45.8%; 95% confidence interval (CI): 29.4 - 64.3] followed by a more moderate increase from 2015 to 2019 (EAPC 16.0%; 95% CI: 12.6-19.6).

CONCLUSIONS

nPEP use increased from 2010 to 2019, but not equally across all risk groups. Further policy interventions should be developed to reduce barriers and ensure adequate access to this important HIV prevention tool.

Doravirine/Lamivudine/Tenofovir Disoproxil Fumarate for Nonoccupational HIV-1 Postexposure Prophylaxis: A Prospective Open-Label Trial (DORAVIPEP)

Background

New regimens may provide better tolerability, convenience, and safety for nonoccupational human immunodeficiency virus (HIV) postexposure prophylaxis (PEP). For this reason, we evaluated the single-tablet regimen of doravirine/lamivudine/tenofovir disoproxil fumarate (DOR/3TC/TDF) for 28 days.

Methods

This was a prospective, open-label, single-arm trial including individuals with potential HIV-1 exposure within 72 hours. The primary endpoint was noncompletion of PEP at day 28. Secondary endpoints were adverse effects, adherence, and rate of seroconversion. We performed follow-up at day 7, week 4, and week 12.

Results

Between September 2019 and March 2022, the study enrolled 399 individuals. Median age was 30 (interquartile range [IQR], 27-36) years, and 91% (n = 364) were male. The mode of exposure was sex between men in 84% (n = 331) of cases; risk assessment for HIV-1 transmission was considered as "high" in 97% (n = 385) of the participants. Median time from exposure to consultation was 24 (IQR, 13-40) hours. Noncompletion of PEP was 29% (n = 114) (95% confidence interval [CI], 24%-33%) and 20% (n = 72) (95% CI, 16%-25%) per modified intention-to-treat. Main reasons for noncompletion were loss to follow-up (n = 104 [91%]) and intolerance (n = 8 [7%]). Older age was associated with a lower risk of premature discontinuation (OR, 0.94; P < .001). One hundred twenty-three (31%) participants reported adverse events, mostly mild and self-limited (82%); discontinuation occurred in 8 cases (2%). Adherence to PEP in the assessed users was 96%. There were no HIV seroconversions.

Conclusions

DOR/3TC/TDF is a well-tolerated option for nonoccupational PEP. Clinical Trials Registration. NCT04233372.

Implementation of HIV non-occupational post-exposure prophylaxis for men who have sex with men in 2 cities of Southwestern China

ABSTRACT

Non-occupational post-exposure prophylaxis (nPEP) has often relied on the joint work of emergency physicians and infectious disease specialists in busy emergency departments and human immunodeficiency virus (HIV)/sexually transmitted infections clinics abroad, where adherence education and follow-up are invariably reactive. In our pilot study, community-based organizations (CBOs) were invited to together implement the nPEP tailored to men who have sex with men (MSM) in 2 cities of Guangxi in Southwestern China, of which experiences and lessons drawn from would be provided to the promotion of nPEP in China.The study population enrolled MSM individuals prescribed nPEP from September 2017 to December 2019. One-to-one follow-ups by CBOs were applied through the treatment. Predictors of treatment completion were assessed by logistic regression.Of 271 individuals presented for nPEP, 266 MSM with documented treatment completion or non-completion, 93.6% completed the 28-day course of medication. Completion was associated with reporting side effects (aOR = .10; 95% CI: 0.02-0.38; P = .001). The follow-up rate of 91.9% was achieved based on the definition of loss to follow-up. No documented nPEP failures were found, although 1 MSM subsequently seroconverted to HIV due to ongoing high-risk behavior.CBOs' engagement in HIV nPEP, especially the "one-to-one" follow-up supports by peer educators partly ensure adherence and retention to nPEP. Tailored interventions are needed to address the subsequent high-risk behaviors among the MSM population.

Adherence to HIV post-exposure prophylaxis for children/adolescents who have been sexually assaulted: A systematic review of barriers, enablers, and interventions

Post-exposure prophylaxis (PEP) is a key intervention for preventing HIV acquisition, including following sexual assault. However, uptake and completion rates for HIV PEP are lowest following sexual assault, with only 40% reporting completing the 28-day course. We undertook a systematic review to assess barriers and enablers to adherence to PEP in children and adolescents following sexual assault and identify potential interventions. Five databases and one conference abstract library were searched using adapted search strategies to identify quantitative and qualitative studies reporting patient-reported barriers and enablers to PEP and randomized trials assessing interventions to improve PEP adherence and completion rates. All searches were conducted up to October 2016; the search was updated in PubMed up to 31 July 2018. 14 studies reported barriers and enablers to PEP adherence. The most commonly cited patient/caregiver reported barriers to PEP adherence/completion included side effects, forgetting, stigma/blame, being busy, poor knowledge, and mental health problems. The most commonly reported factors associated with PEP adherence/completion (reported across 7 studies) included health provider encouragement to take PEP (type of encouragement not described), perpetrator known to be HIV-positive, monetary support for transport, the victim of assault attending counseling, being reminded by family/peers to take PEP, and "one-stop" services offering both HIV testing and PEP at initial consultation. Three randomized trials provided limited evidence supporting the potential benefit of enhanced adherence support for HIV PEP; however, data for children were lacking. Despite low completion rates, there is limited research into causes of and interventions to improve adherence to PEP following sexual assault, and no direct evidence for children.

Conditions associated with adherence to HIV post-sexual exposure prophylaxis

OBJECTIVE

To analyze conditions which interfere with adherence to HIV post-sexual exposure prophylaxis.

METHOD

Cross-sectional study conducted in two health care services specializing in HIV/AIDS in São Paulo city. Interviewees included men and women who were eighteen or older, sought care due to consensual sexual relation, and had a recommendation for prophylaxis. The questionnaires which compose the social reproduction index and adherence to prophylaxis were used as parameters. Non-parametric Kruskal-Wallis and Mann-Whitney tests and summation of the employed instrument through programs Excel® and Statistical Package for the Social Sciences® were performed. Ethical principles have been respected.

RESULTS

Forty-nine users have been identified; their mean age was 34.7 and they were predominantly men (95.9%). Out of these, 83.6% were men who have sex with men. The conditions which correlated with adherence (p<0.05) were taking post-sexual exposure prophylaxis prior to that appointment and continuing to take the medication.

CONCLUSION

Health professionals are responsible for establishing rapport with service users, especially during the first appointment, to contribute to adherence interventions plans.

Pre and Post-exposure Prophylaxis Awareness and Acceptability Among Sex Workers in Jamaica: A Cross-Sectional Study

The HIV prevention cascade is understudied among sex workers in Jamaica, where sex work and same sex practices are criminalized. We implemented a cross-sectional survey with cisgender women, transgender women, and cisgender men sex workers in Jamaica. We conducted multivariable logistic regression analyses to identify factors associated with PrEP and PEP awareness and acceptability. Participants (n = 340) included cisgender men (n = 124), transgender women (n = 101), and cisgender women (n = 115). PEP awareness was low (33.2%), yet acceptability was high (70.8%). In multivariable analyses, recent sexual violence, recent client violence, and sex work social cohesion were associated with PEP awareness and acceptability. One-third (32.7%) reported PrEP awareness, with high acceptability (80.2%). Relationship status and recent physical violence were associated with PrEP awareness and acceptability. In multivariable analyses, gender identity was not associated with differences in PEP/PrEP awareness/acceptability. Findings highlight the need to increase PEP and PrEP awareness and access among sex workers in Jamaica.

Elvitegravir-Cobicistat-Emtricitabine-Tenofovir Alafenamide Single-tablet Regimen for Human Immunodeficiency Virus Postexposure Prophylaxis

We evaluated an elvitegravir-cobicistat-emtricitabine-tenofovir alafenamide single-tablet regimen for human immunodeficiency virus postexposure prophylaxis. The completion rate and adherence were good, and the tolerance was acceptable; no seroconversion was observed. We confirm that this regimen could be appropriate for postexposure prophylaxis.

CLINICAL TRIALS REGISTRATION

NCT02998320.

Nonoccupational post-exposure prophylaxis for HIV after sexual intercourse among women in Brazil: Risk profiles and predictors of loss to follow-up

Access to antiretroviral-based HIV prevention has been marked by sex asymmetries, and its effectiveness has been compromised by low clinical follow-up rates. We investigated risk profiles of women who received nonoccupational post-exposure prophylaxis (nPEP), as well as the rates and predictive factors of loss to follow-up after nPEP initiation.Retrospective study evaluating 501 women who received nPEP between 2014 and 2015 at 5 HIV centers (testing centers-VCT, outpatient clinics, and infectious diseases hospital). Risk profiles were drawn based on the characteristics of the women and their sexual partners, and then stratified by sociodemographic indicators and previous use of HIV prevention services. Loss to follow-up (LTFU) was defined as not presenting for follow-up visits or for HIV testing after nPEP initiation. Predictors of LTFU were analyzed by calculating adjusted prevalence ratios (aPRs).Approximately 90% of women had sexual encounters that met the criteria established in the Brazilian guidelines for nPEP. Those who declared to be sex workers (26.5%) or drug users (19.2%) had the highest social vulnerability indicators. In contrast, women who had intercourse with casual partners of unknown HIV risk (42.7%) had higher education and less experience with previous HIV testing (89.3%) or nPEP use (98.6%). Of the women who received nPEP after sexual intercourse with stable partners, 75.8% had HIV-infected partners. LTFU rate was 72.8% and predictors included being Black (aPR = 1.15, 95% confidence interval [CI]: 1.03-1.30), using drugs/alcohol (aPR = 1.15, 95% CI: 1.01-1.32) and having received nPEP at an HIV outpatient clinic (aPR = 1.35, 95% CI: 1.20-1.51) or at an infectious diseases hospital (aPR = 1.37, 95% CI: 1.11-1.69) compared with a VCT. The risk of LTFU declined as age increased (aPR 41-59 years = 0.80, 95% CI: 0.68-0.96).Most women who used nPEP had higher socioeconomic status and were not part of populations most affected by HIV. In contrast, factors that contribute to loss to follow-up were: having increased social vulnerability; increased vulnerability to HIV infection; and seeking nPEP at HIV treatment services as opposed to at a VCT.

A mixed methods study of non-occupational post-exposure prophylaxis at an STI clinic in Singapore: Five-year retrospective analysis and providers' perspectives

BACKGROUND

This mixed methods study aims to describe 1) characteristics of the population treated with non-occupational post-exposure prophylaxis (nPEP), 2) predictors of loss to follow-up (LTFU) and nPEP adherence, and 3) to evaluate the nPEP prescribing practices against current management guideline.

METHODS

This study was conducted at the Department of Sexually Transmitted Infections Control Clinic in Singapore using clinical data from 2010 to 2016. Explanatory sequential mixed method design was adopted. Predictors of LTFU and nPEP adherence were assessed using modified Poisson regression with robust sandwich variance. Subsequently, nine in-depth interviews with healthcare providers were conducted to gain their insights into barriers and facilitators to nPEP implementation. Transcripts were coded and themes were explored using applied thematic analysis.

RESULTS

Of 502 nPEP cases reviewed, 46% were LTFU, 42% were adherent to nPEP and 431 prescription decisions were made in accordance with the guideline. Tourists (aRR, 2.29 [1.90-2.74]; p<0.001) and men who have sex with men/bisexual men (aRR, 1.32 [1.09-1.59]; p = 0.004) were significant predictors of LTFU. Absence of side effects (aRR, 1.14 [1.02-1.27]; p = 0.024) and nPEP treatment with TDF/FTC/ATV/r (aRR, 1.15 [1.03-1.29]; p = 0.017) were positively associated with nPEP adherence. Stigma, types of antiretroviral regimen, side effects, and patients' perception of risk and treatment benefits derived qualitatively further reinforced corresponding quantitative findings.

CONCLUSION

Tailored socio-behavioral interventions are needed to address inherent differences within heterogeneous populations requesting nPEP, stigma, and patients' perceptions of nPEP in order to improve follow-up and its adherence.

[From evidence to action: challenges for the Brazilian Unified National Health System in offering pre-exposure prophylaxis (PrEP) for HIV to persons with the greatest vulnerability]

Pre-exposure prophylaxis (PrEP) has been considered a promising strategy for controlling the global HIV epidemic. However, it is necessary to translate the knowledge accumulated from clinical trials and demosntration studies to the reality of health services and the groups most vulnerable to infection in order to achieve broad coverage with PrEP. The article proposes a reflection on this challenge, focusing on three dimensions: users of prophylaxis, with an emphasis on the contexts of sexual practices and the potential exposures to HIV; the advantages of prophylaxis as compared to other methods and the challenges for protective and safe use; and health services, considering the organizational principles to ensure greater success in the supply and incorporation of PrEP as part of combination prevention strategies. The following principles were analyzed: uniqueness of care, freedom of choice and non-hierarchization of prevention methods, sexual risk management, scheduling flexibility, and complementary and multidisciplinary care. These principles can foster organization of the health service and care, facilitating linkage and retention in care. Some comments were offered on the relative incompatibility between the existing structure of services and the Brazilian Ministry of Health guidelines for offering PrEP. The conclusion was that the success of PrEP as a public health policy depends on two essential factors: ensuring that health services are culturally diverse settings, free of discrimination, and the intensification of community-based interventions, including social networks, in order to reduce inequalities in access to PrEP and health services as a whole.

The effect of prevention methods on reducing sexual risk for HIV and their potential impact on a large-scale: a literature review

A spectrum of diverse prevention methods that offer high protection against HIV has posed the following challenge: how can national AIDS policies with high coverage for prevention and treatment make the best use of new methods so as to reverse the current high, and even rising, incidence rates among specific social groups? We conducted a narrative review of the literature to examine the prevention methods and the structural interventions that can have a higher impact on incidence rates in the context of socially and geographically concentrated epidemics. Evidence on the protective effect of the methods against sexual exposure to HIV, as well as their limits and potential, is discussed. The availability and effectiveness of prevention methods have been hindered by structural and psychosocial barriers such as obstacles to adherence, inconsistent use over time, or only when individuals perceive themselves at higher risk. The most affected individuals and social groups have presented limited or absence of use of methods as this is moderated by values, prevention needs, and life circumstances. As a result, a substantial impact on the epidemic cannot be achieved by one method alone. Programs based on the complementarity of methods, the psychosocial aspects affecting their use and the mitigation of structural barriers may have the highest impact on incidence rates, especially if participation and community mobilization are part of their planning and implementation.

Prescription of Postexposure Prophylaxis for HIV-1 in the Emergency Room: Correct Transmission Risk Assessment Remains Challenging

BACKGROUND

Limited data are available about the accuracy of postexposure prophylaxis (PEP) prescription in the emergency rooms. Here, we evaluated PEP prescription decision making with respect to the risk of sexual HIV transmission and the exposed person's fear vis-à-vis HIV.

METHODS

Using a risk assessment algorithm, we retrospectively evaluated the adequacy of PEP prescription for all persons presenting at the emergency room of the University Hospital Zurich after consensual sex from 2007 to 2013. We used logistic regression to identify factors that correlate with risk-concordant and risk-discordant decisions.

RESULTS

We documented 975 persons with a total of 1051 visits for PEP: 83% were men, 71% were Swiss, and 37% were men who have sex with men. In 74% of visits, the decisions were concordant with the risk evaluation algorithm (22% discordant, 4% unknown). In 61% (644/1051) PEP was prescribed; however, in 12% (76/644) the prescriptions were without indication of HIV transmission risk and were attributed to the exposed person's request. Importantly, in 10% (101/1051) of all visits, there were potential risks but PEP was not prescribed, either because of physician's decision or exposed person's refusal. The presence of the source partner strongly correlated with appropriately withholding PEP (adjusted odds ratio for giving PEP 0.05; 95% confidence interval: 0.03 to 0.08).

CONCLUSIONS

We found that 22% of PEP decisions were risk discordant because of exposed person's request, incorrect estimation of the sexual transmission risk by the physician, or exposed person's refusal to accept PEP. Emergency physicians may benefit from specialized risk assessment training and patients from education in HIV transmission risk awareness.

Two, three, and four-drug regimens for HIV post-exposure prophylaxis in a North American sexual assault victim population

BACKGROUND/OBJECTIVES

Due to perceived increased tolerability and compliance, and decreased cost, recent trends in practice are moving towards using fewer drugs for HIV post-exposure prophylaxis. However, there is limited literature to assess this is in the North American sexual assault victim population.

METHODS

This retrospective before-and-after cohort study compared patients seen at a sexual assault care facility before and after the introduction of two and three-drug post-exposure prophylaxis regimens. Our primary outcome was completion of the 28-day regimen. Secondary objectives included HIV seroconversion rates and patient reported side effects.

RESULTS

Six-hundred-thirty charts from a 2-year period were reviewed, and 429 met inclusion criteria. There was no difference in completion rates of post-exposure prophylaxis between the two cohorts (50.5% vs. 51.6%). However, there were fewer reported side effects (72.2% vs. 17.6%) in the later cohort. We subsequently compared all patients in either cohort who received four-drug therapy (N=128) versus those who received two or three-drug regimens (N=47). The two or three-drug regimen group had a higher completion rate (66.0% vs. 42.2%; p=0.03), and a lower rate of reported side effects (19.1% vs. 53.9%), specifically for nausea (12.8% vs. 36.7%), constipation (0% vs. 7.9%), diarrhea (2.1% vs. 21.1%), mood changes (0% vs. 10.9%), headache (2.1% vs. 16.4%), and fatigue (6.4% vs. 26.6%). There were no HIV seroconversions in either group.

CONCLUSION

Two and three-drug HIV post-exposure prophylaxis regimens are better tolerated by patients and associated with greater compliance than four-drug therapy, and could be considered in the sexual assault victim population.

Constructing the cascade of HIV care: methods for measurement

PURPOSE OF REVIEW

Although the concept of the HIV treatment cascade has reached nearly ubiquitous acceptance in international HIV policy and research, methods for estimating it vary drastically. These variations become increasingly important as the focus of the HIV response shifts from emergency response to long-term outcomes and financial and organizational sustainability. We review the history of the cascade and the current literature and develop the first comprehensive typology of cascade scope and methods.

RECENT FINDINGS

We define the cascade scope in terms of both breadth (range from first to final event) and depth (given breadth, number of cascade stages that analyzed). We distinguish cascade measurement according to four dimensions: denominator-denominator linkage (data used for cascade construction are linked at the individual level across stages); denominator-numerator linkage (data are linked at the individual level within each stage); single vs. multiple populations from which data sources are drawn; and longitudinal vs. cross-sectional design.

SUMMARY

Everything else equal, we would prefer broader and deeper cascades, denominator-denominator linkage, denominator-numerator linkage, single population, and longitudinal data over their respective alternatives. Increased investments in population-based cohorts and data linkage are required to complement clinical cohorts for 'broad' longitudinal cascade analyses.

High Levels of Concomitant Behavioral Health Disorders Among Patients Presenting for HIV Non-occupational Post-exposure Prophylaxis at a Boston Community Health Center Between 1997 and 2013

A paucity of information regarding mental health exists for patients presenting for HIV non-occupational post-exposure prophylaxis (nPEP). We reviewed electronic medical records of 894 adult nPEP patients seen at a large Boston community health center between 1997 and 2013. Of 821 patients with consensual sexual exposures, 88.3 % were men who have sex with men, and 40.0 % had a mental health diagnosis. Diagnoses included: depression (24.4 %), anxiety (21.9 %), attention deficit disorder (7.8 %), post-traumatic stress disorder (3.3 %), and psychotic disorders (3.3 %). Of 129 patients with substance use disorders, alcohol dependence (65.9 %) and crystal methamphetamine (43.4 %) predominated. Unprotected receptive anal intercourse was associated with psychotic disorders (aOR = 4.86; 95 %CI:1.76-13.5) and substance use disorders (aOR = 1.89; 95 %CI:1.28-2.80). Substance use at the time of exposure was associated with: depression (aOR = 1.95; 95 %CI:1.36-2.80), anxiety (aOR = 2.22; 95 %CI:1.51-3.25), attention deficit disorder (aOR = 1.96; 95 %CI:1.18-3.27), and substance use disorder (aOR = 4.78; 95 %CI:3.30-6.93). Mental illness should be screened for and addressed at nPEP visits to optimize HIV risk-reduction.

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.

Adherence to Post-Exposure Prophylaxis (PEP) and Incidence of HIV Seroconversion in a Major North American Cohort

Background

There is limited evidence on the efficacy of post-exposure prophylaxis (PEP) for sexual exposures. We sought to determine the factors associated with adherence to treatment and describe the incidence of PEP failures in a Montreal clinic.

Methods

We prospectively assessed all patients consulting for PEP following sexual exposures from October 2000 to July 2014. Patients were followed at 4 and 16 weeks after starting PEP. Treatment adherence was determined by self-report at week 4. Multivariable logistic regression was used to estimate the factors predicting adherence to treatment.

Results

3547 PEP consults were included. Patients were mainly male (92%), MSM (83%) and sought PEP for anal intercourse (72%). Seventy-eight percent (n = 2772) of patients received a prescription for PEP, consisting of Tenofovir/Emtracitabine (TVD) + Lopinavir/Ritonavir (LPV) in 74% of cases, followed by Zidovudine/Lamivudine (CBV) + LPV (10%) and TVD + Raltegravir (RAL) (8%). Seventy percent of patients were adherent to treatment. Compared to TVD+LPV, patients taking CBV+LPV were less likely to adhere to treatment (OR 0.58, 95% CI 0.44–0.75), while no difference was observed for patients taking TVD+RAL (OR 1.15, 95% CI 0.83–1.59). First-time PEP consults, older and male patients were also more adherent to treatment. Ten treated patients seroconverted (0.37%) during the study period, yet only 1 case can be attributed to PEP failure (failure rate = 0.04%).

Conclusion

PEP regimen was associated with treatment adherence. Patients were more likely to be adherent to TVD-based regimens. Ten patients seroconverted after taking PEP; however, only 1 case was a PEP failure as the remaining patients continued to engage in high-risk behavior during follow-up. One month PEP is an effective preventive measure to avoid HIV infection.

Pre-exposure and postexposure prophylaxes and the combination HIV prevention methods (The Combine! Study): protocol for a pragmatic clinical trial at public healthcare clinics in Brazil

INTRODUCTION

Few results from programmes based on combination prevention methods are available. We propose to analyse the degree of protection provided by postexposure prophylaxis (PEP) for consensual sexual activity at healthcare clinics, its compensatory effects on sexual behaviour; and the effectiveness of combination prevention methods and pre-exposure prophylaxis (PrEP), compared with exclusively using traditional methods.

METHODS AND ANALYSIS

A total of 3200 individuals aged 16 years or older presenting for PEP at 5 sexually transmitted disease (STD)/HIV clinics in 3 regions of Brazil will be allocated to one of two groups: the PEP group-individuals who come to the clinic within 72 h after a sexual exposure and start PEP; and the non-PEP group-individuals who come after 72 h but within 30 days of exposure and do not start PEP. Clinical follow-up will be conducted initially for 6 months and comprise educational interventions based on information and counselling for using prevention methods, including PrEP. In the second study phase, individuals who remain HIV negative will be regrouped according to the reported use of prevention methods and observed for 18 months: only traditional methods; combined methods; and PrEP. Effectiveness will be analysed according to the incidence of HIV, syphilis and hepatitis B and C and protected sexual behaviour. A structured questionnaire will be administered to participants at baseline and every 6 months thereafter. Qualitative methods will be employed to provide a comprehensive understanding of PEP-seeking behaviour, preventive choices and exposure to HIV.

ETHICS AND DISSEMINATION

This study will be conducted in accordance with the resolution of the School of Medicine Research Ethics Commission of Universidade de São Paulo (protocol no. 251/14). The databases will be available for specific studies, after management committee approval. Findings will be presented to researchers, health managers and civil society members by means of newspapers, electronic media and scientific journals and meetings.

Optimizing adherence to preexposure and postexposure prophylaxis: the need for an integrated biobehavioral approach

Preexposure prophylaxis (PrEP) and postexposure prophylaxis (PEP) has been shown to be effective in preventing transmission of human immunodeficiency virus (HIV). A dose-response relationship between adherence and HIV transmission is illustrated in the current PrEP literature, and adherence interventions for PrEP may be useful, although currently few effective programs have been developed and tested. There is a paucity of randomized controlled trials testing PEP adherence interventions, and further research is needed. We conclude by proposing the importance of tailoring adherence counseling to address psychosocial factors and mental health stressors that may negatively affect adherence.

State-level structural sexual stigma and HIV prevention in a national online sample of HIV-uninfected MSM in the United States

BACKGROUND

Stigmatizing social environments (of which 'structural stigma' is one component) negatively affect health-related outcomes. However, few studies have examined structural stigma related to sexual minority status as a risk factor for HIV outcomes among MSM.

METHODS

In August 2013, members of a large MSM social and sexual networking site in the United States completed a survey about HIV-prevention practices. A previously validated composite index provided values for state-level structural stigma, including density of same-sex couples, proportion of public high schools with Gay-Straight Alliances, state laws protecting sexual minorities, and public opinion toward homosexuality. Multivariable logistic generalized estimating equations assessed the relationship between structural stigma and condomless anal intercourse, use and awareness of antiretroviral-based HIV-prevention strategies (i.e. pre and postexposure prophylaxis, or PEP and PrEP), and comfort discussing male-male sex with primary care providers.

RESULTS

Among the 4098 HIV-uninfected MSM, lower state-level structural stigma was associated with decreased odds of condomless anal intercourse [adjusted odds ratio (aOR) 0.97 per one unit increase in structural stigma score, 95% confidence interval (CI) 0.94-0.99], increased odds of awareness of PEP (aOR 1.06, 95% CI 1.02-1.09), and PrEP (aOR 1.06, 95% CI 1.02-1.10), having taken PEP (aOR 1.15, 95% CI 1.05-1.26) and PrEP (aOR 1.21, 95% CI 1.01-1.44), and comfort discussing male-male sex with providers (aOR 1.08, 95% CI 1.05-1.11), after adjusting for social and state-level confounders.

CONCLUSION

MSM living in more stigmatizing environments had decreased use of antiretroviral-based HIV-prevention strategies compared to those in less stigmatizing environments. Legal reforms protecting sexual minorities should be evaluated as structural interventions that could reduce HIV risk among MSM.

Contingency management facilitates the use of postexposure prophylaxis among stimulant-using men who have sex with men

Compared to a control behavioral intervention, Contingency Management, an escalating voucher-based incentive system to reinforce stimulant abstinence, better supported MSM stimulant users in PEP course completion, decreased stimulant use, and a trend toward fewer condomless sexual acts.

Background. Stimulant-using men who have sex with men (MSM) are at high risk of human immunodeficiency virus (HIV) acquisition. Contingency Management (CM) is a robust substance abuse intervention that provides voucher-based incentives for stimulant-use abstinence.

Methods. We conducted a randomized controlled trial of CM with postexposure prophylaxis (PEP) among stimulant-using MSM. Participants were randomized to CM or a noncontingent “yoked” control (NCYC) intervention and observed prospectively. Generalized linear models were used to estimate the effect of CM on PEP course completion, medication adherence, stimulant use, and sexual risk behaviors.

Results. At a single site in Los Angeles, 140 MSM were randomized to CM (n = 70) or NCYC (n = 70). Participants were 37% Caucasian, 37% African American, and 18% Latino. Mean age was 36.8 (standard deviation = 10.2) years. Forty participants (29%) initiated PEP after a high-risk sexual exposure, with a mean exposure-to-PEP time of 32.9 hours. PEP course completion was greater in the CM group vs the NCYC group (adjusted odds ratio [AOR] 7.2; 95% confidence interval {CI}, 1.1–47.9), with a trend towards improved medication adherence in the CM group (AOR, 4.3; 95% CI, 0.9–21.9).

Conclusions. CM facilitated reduced stimulant use and increased rates of PEP course completion, and we observed a trend toward improved adherence. Participants in the CM group reported greater reductions in stimulant use and fewer acts of condomless anal intercourse than the control group. This novel application of CM indicated the usefulness of combining a CM intervention with PEP to produce a synergistic HIV prevention strategy that may reduce substance use and sexual risk behaviors while improving PEP parameters.

Post-exposure prophylaxis use and recurrent exposure to HIV among men who have sex with men who use crystal methamphetamine

BACKGROUND

Men who have sex with men (MSM) who use crystal methamphetamine (CM) are at increased risk for HIV infection. Post-exposure prophylaxis (PEP) is a useful HIV prevention strategy if individuals are able to identify high-risk exposures and seek timely care, however to date there has been limited data on the use of PEP by CM users.

METHODS A

Retrospective cohort study of all PEP prescriptions (N=1130 prescriptions among 788 MSM) at Fenway Community Health in Boston, MA was undertaken. Multivariable models were used to assess the association between CM use during exposure (7.4% used CM during exposure) and chronically (7.4% of MSM were chronic CM users) and individual-level and event-level outcomes among MSM who used PEP at least once.

RESULTS

Compared to those who had not used CM, MSM PEP users who used CM more frequently returned for repeat PEP (aOR 5.13, 95% CI 2.82 to 9.34) and were significantly more likely to seroconvert over the follow-up period (aHR 3.61, 95% CI 1.51 to 8.60). MSM who used CM had increased odds of unprotected anal intercourse as the source of exposure (aOR 2.12, 95% CI 1.16 to 3.87) and knowing that their partner was HIV infected (aOR 2.27, 95% CI 1.42 to 3.64).

CONCLUSIONS

While MSM who use CM may have challenges accessing ART in general, these data highlight the fact that those who were able to access PEP subsequently remained at increased risk of HIV seroconversion. Counseling and/or substance use interventions during the PEP course should be considered for CM-using MSM.

Adherence to HIV postexposure prophylaxis: a systematic review and meta-analysis

INTRODUCTION

We evaluated variations in completion rates for HIV postexposure prophylaxis (PEP) according to the exposure type (occupational, nonoccupational, and sexual assault), patient, and programme characteristics.

METHODS

Four major databases were searched together with conference abstract databases from inception to 1 December 2013, updated in PubMed on 1 June 2014. Randomized and nonrandomized studies reporting completion rates for PEP were included regardless of exposure type, age, or geographical location and data pooled using random-effects meta-analysis.

RESULTS

Ninety-seven studies, reporting outcomes on 21 462 PEP initiations, were reviewed. Nonoccupational exposure to HIV was the main reason for PEP in 34 studies (n = 11 840), occupational exposure in 22 studies (n = 3058), sexual assault in 26 studies (n = 3093), and the remainder of studies (15 studies, n = 3471) reported outcomes for mixed exposures. Overall, 56.6% [95% confidence (CI) 50.9-62.2%; τ(2) 0.25] of people considered eligible for PEP completed the full standard 28-day course. Compared with the overall estimate of PEP completion, rates were highest for studies reporting PEP for nonoccupational exposures (65.6%, 95% CI 55.6-75.6%) and lowest for sexual assault (40.2%, 95% CI 31.2-49.2%); higher rates of PEP completion were also reported for MSM (67.2%, 95% CI 59.5-74.9%). Completion rates appeared to be lower for adolescents (36.6%, 95% CI 4.0-69.2%) compared with adults (59.1%, 95% CI 53.9-64.2%) or children (64.0%, 95% CI 41.2-86.8%).

CONCLUSION

Adherence to a full 28-day course of antiretroviral drugs prescribed for PEP is poor. Efforts should be made to simplify guidelines for prescribers and support adherence for people taking PEP, with particular attention needed for adolescents and victims of sexual assault.

Current perspectives in HIV post-exposure prophylaxis

The incidence of human immunodeficiency virus (HIV) infection continues to rise among core groups and efforts to reduce the numbers of new infections are being redoubled. Post-exposure prophylaxis (PEP) is the use of short-term antiretroviral therapy (ART) to reduce the risk of acquisition of HIV infection following exposure. Current guidelines recommend a 28-day course of ART within 36-72 hours of exposure to HIV. As long as individuals continue to be exposed to HIV there will be a role for PEP in the foreseeable future. Nonoccupational PEP, the vast majority of which is for sexual exposure (PEPSE), has a significant role to play in HIV prevention efforts. Awareness of PEP and its availability for both clinicians and those who are eligible to receive it are crucial to ensure that PEP is used to its full potential in any HIV prevention strategy. In this review, we provide current evidence for the use of PEPSE, assessment of the risk of HIV transmission, indications for PEP, drug regimens, and management of patients started on PEP. We summarize national and international guidelines for the use of PEPSE. We explore the place of PEP within the wider strategy of reducing HIV incidence rates in the era of treatment as prevention and pre-exposure prophylaxis. We also consider the implications of recent data from interventional and observational studies demonstrating significant reductions in the risk of HIV transmission within a serodiscordant relationship if the HIV-positive partner is taking effective ART upon PEP guidelines.

Global burden of HIV among men who engage in transactional sex: a systematic review and meta-analysis

BACKGROUND

Men who engage in transactional sex, the exchange of sex for money, goods, or other items of value, are thought to be at increased risk of HIV, but there have been no systematic attempts to characterize HIV burden in this population. We undertook a systematic review and meta-analysis to quantify the burden in this population compared with that of men in the general population to better inform future HIV prevention efforts.

METHODS

We searched seven electronic databases, national surveillance reports, and conference abstracts for studies of men who engage in transactional sex published between 2004-2013. Random effects meta-analysis was used to determine pooled HIV prevalence and prevalence ratios (PR) for the difference in HIV prevalence among men who engage in transactional sex as compared to general population men.

FINDINGS

Of 66 studies included representing 31,924 men who had engaged in transactional sex in 28 countries, pooled biological assay-confirmed HIV prevalence was 10.5% (95% CI = 9.4 to 11.5%). The highest pooled HIV prevalence was in Sub-Saharan Africa (31.5%, 95% CI = 21.6 to 41.5%), followed by Latin America (19.3%, 95% CI = 15.5 to 23.1%), North America (16.6%, 95% CI = 3.7 to 29.5%), and Europe (12.2%, 95% CI = 6.0 to 17.2%). Men who engaged in transactional sex had an elevated burden of HIV compared to the general male population (PR = 20.7, 95% CI = 16.8 to 25.5).

CONCLUSIONS

The global burden of HIV is disproportionately high among men who engage in transactional sex compared with the general male population. There is an urgent need to include this population in systematic surveillance as well as to scale-up access to quality HIV prevention programs.