Acquisition of tenofovir-susceptible, emtricitabine-resistant HIV despite high adherence to daily pre-exposure prophylaxis: a case report

Oral HIV pre-exposure prophylaxis use and resistance-associated mutations among men who have sex with men and transgender persons newly diagnosed with HIV in the Netherlands: results from the ATHENA cohort, 2018 to 2022

BackgroundIn the Netherlands, HIV pre-exposure prophylaxis (PrEP) has been available since 2019. However, the extent of PrEP use prior to HIV diagnosis and development of PrEP-resistance-associated mutations (RAMs) is not known.AimWe assessed prior PrEP use and potential transmission of PrEP RAMs among men who have sex with men (MSM) and transgender persons (TGP) with a new HIV diagnosis in the Netherlands.MethodsData on prior PrEP use between 1 January 2018 and 31 December 2022 were available from the Dutch national ATHENA cohort. We assessed proportion of prior PrEP use, detected PrEP associated RAMs and assessed potential onward transmission of RAMs between 2010 and 2022 using a maximum likelihood tree.ResultsData on prior PrEP use were available for 583/1,552 (36.3%) individuals, with 16% (94/583) reporting prior PrEP use. In 489 individuals reporting no prior PrEP use, 51.5% did not use PrEP due to: low HIV-risk perception (29%), no access (19.1%), personal preference (13.1%), and being unaware of PrEP (19.1%). For PrEP users, 13/94 (13.8%) harboured a M184V/I mutation, of whom two also harboured a K65R mutation. In people with a recent HIV infection, detection of PrEP RAMs increased from 0.23% (2/862) before 2019 to 4.11% (9/219) from 2019. We found no evidence of onward transmission of PrEP RAMs.ConclusionThe prevalence of PrEP-associated RAMs has increased since PrEP became available in the Netherlands. More widespread access to PrEP and retaining people in PrEP programmes when still at substantial risk is crucial to preventing new HIV infections.

Rapid Biphasic Decay of Intact and Defective HIV DNA Reservoir During Acute Treated HIV Disease

Despite antiretroviral therapy (ART), HIV persists in latently-infected cells ("the reservoir") which decay slowly over time. Here, leveraging >500 longitudinal samples from 67 people with HIV (PWH) treated during acute infection, we developed a novel mathematical model to predict reservoir decay from peripheral CD4+ T cells. Nonlinear generalized additive models demonstrated rapid biphasic decay of intact DNA (week 0-5: t1/2~2.83 weeks; week 5-24: t1/2~15.4 weeks) that extended out to 1 year. These estimates were ~5-fold faster than prior decay estimates among chronic treated PWH. Defective DNA had a similar biphasic pattern, but data were more variable. Predicted intact and defective decay rates were faster for PWH with earlier timing of ART initiation, higher initial CD4+ T cell count, and lower pre-ART viral load. These data add to our limited understanding of HIV reservoir decay at the time of ART initiation, informing future curative strategies targeting this critical time.

Tenofovir Activation Is Diminished in the Brain and Liver of Creatine Kinase Brain-Type Knockout Mice

Tenofovir (TFV) is a nucleotide reverse transcriptase inhibitor prescribed for the treatment and prevention of human immunodeficiency virus infection and the treatment of chronic hepatitis B virus infection. Here, we demonstrate that creatine kinase brain-type (CKB) can form tenofovir-diphosphate (TFV-DP), the pharmacologically active metabolite, in vitro and identify nine missense mutations (C74S, R96P, S128R, R132H, R172P, R236Q, C283S, R292Q, and H296R) that diminish this activity. Additional characterization of these mutations reveals that five (R96P, R132H, R236Q, C283S, and R292Q) have ATP dephosphorylation catalytic efficiencies less than 20% of those of the wild type (WT), and seven (C74S, R96P, R132H, R172P, R236Q, C283S, and H296P) induce thermal instabilities. To determine the extent CKB contributes to TFV activation in vivo, we generated a CKB knockout mouse strain, Ckbtm1Nnb. Using an in vitro assay, we show that brain lysates of Ckbtm1Nnb male and female mice form 70.5 and 77.4% less TFV-DP than wild-type brain lysates of the same sex, respectively. Additionally, we observe that Ckbtm1Nnb male mice treated with tenofovir disoproxil fumarate for 14 days exhibit a 22.8% reduction in TFV activation in the liver compared to wild-type male mice. Lastly, we utilize mass spectrometry-based proteomics to elucidate the impact of the knockout on the abundance of nucleotide and small molecule kinases in the brain and liver, adding to our understanding of how the loss of CKB may be impacting tenofovir activation in these tissues. Together, our data suggest that disruptions in CKB may lower levels of active drugs in the brain and liver.

Prevention, treatment and cure of HIV infection

The development of antiretroviral therapy for the prevention and treatment of HIV infection has been marked by a series of remarkable successes. However, the efforts to develop a vaccine have largely failed, and efforts to discover a cure are only now beginning to gain traction. In this Review, we describe recent progress on all fronts - pre-exposure prophylaxis, vaccines, treatment and cure - and we discuss the unmet needs, both current and in the coming years. We describe the emerging arsenal of drugs, biologics and strategies that will hopefully address these needs. Although HIV research has largely been siloed in the past, this is changing, as the emerging research agenda is marked by multiple cross-discipline synergies and collaborations. As the limitations of antiretroviral drugs as a means to truly end the epidemic are becoming more apparent, there is a great need for continued efforts to develop an effective preventative vaccine and a scalable cure, both of which remain formidable challenges.

Tenofovir Activation is Diminished in the Brain and Liver of Creatine Kinase Brain-Type Knockout Mice

Tenofovir (TFV) is a nucleotide reverse transcriptase inhibitor prescribed for the treatment and prevention of human immunodeficiency virus infection, and the treatment of chronic hepatitis B virus infection. Here, we demonstrate that creatine kinase brain-type (CKB) can form tenofovir-diphosphate (TFV-DP), the pharmacologically active metabolite, in vitro, and identify nine missense mutations (C74S, R96P, S128R, R132H, R172P, R236Q, C283S, R292Q, and H296R) that diminish this activity. Additional characterization of these mutations reveal that five (R96P, R132H, R236Q, C283S, and R292Q) have ATP dephosphorylation catalytic efficiencies less than 20% of wild-type (WT), and seven (C74S, R96P, R132H, R172P, R236Q, C283S, and H296P) induce thermal instabilities. To determine the extent CKB contributes to TFV activation in vivo, we generated a CKB knockout mouse strain, Ckbtm1Nnb. Using an in vitro assay, we show that brain lysates of Ckbtm1Nnb male and female mice form 70.5% and 77.4% less TFV-DP than wild-type brain lysates of the same sex, respectively. Additionally, we observe that Ckbtm1Nnb male mice treated with tenofovir disoproxil fumarate for 14 days exhibit a 22.8% reduction in TFV activation in liver compared to wild-type male mice. Lastly, we utilize mass spectrometry-based proteomics to elucidate the impact of the knockout on the abundance of nucleotide and small molecule kinases in the brain and liver, adding to our understanding of how loss of CKB may be impacting tenofovir activation in these tissues. Together, our data suggest that disruptions in CKB may lower levels of active drug in brain and liver.

Breakthrough HIV-1 infection in setting of cabotegravir for HIV pre-exposure prophylaxis

OBJECTIVE

We describe the first case of HIV-1 infection in the setting of long-acting injectable cabotegravir (CAB-LA) for HIV pre-exposure prophylaxis to occur in the real world.

DESIGN

Case report.

METHODS

Electronic medical records were reviewed to assess patient history and CAB-LA administration details. Plasma fourth-generation HIV-1/2 Ag/Ab combination immunoassay and HIV-1 RNA quantitative PCR were performed at each injection visit.

RESULTS

We report a 28-year-old sex-diverse person assigned male at birth who acquired HIV-1 infection 91 days after transitioning from tenofovir alafenamideemtricitabine to CAB-LA despite on-time dosing and appropriate laboratory monitoring.

CONCLUSION

This patient's history suggests HIV infection despite on-time and appropriate CAB-LA injections. To our knowledge, this is the first case of CAB-LA pre-exposure prophylaxis failure outside the setting of a clinical trial and highlights diagnostic and management challenges that may occur with such breakthrough infections.

Human Immunodeficiency Virus Seroconversion Among Men Who Have Sex With Men Who Use Event-Driven or Daily Oral Pre-Exposure Prophylaxis (CohMSM-PrEP): A Multi-Country Demonstration Study From West Africa

BACKGROUND

Data on human immunodeficiency virus (HIV) seroconversion among men who have sex with men (MSM) using pre-exposure prophylaxis (PrEP) in West Africa are needed. This study aimed to document HIV seroconversion and associated determinants, PrEP adherence, plasma drug concentrations, and HIV drug resistance in MSM using event-driven or daily PrEP in Burkina Faso, Côte d'Ivoire, Mali, and Togo.

METHODS

A prospective cohort study was conducted in 2017-2021 among HIV-seronegative MSM aged 18 or over who were at high risk of HIV infection. Participants could choose between event-driven and daily PrEP, switch regimens, and discontinue or restart PrEP. The determinants of HIV incidence were investigated using a multivariate mixed-effects Poisson regression analysis.

RESULTS

A total of 647 participants were followed for a total time of 1229.3 person-years. Of 5371 visits, event-driven PrEP was chosen in 3873 (72.1%), and daily PrEP in 1400 (26.1%). HIV incidence was 2.4 per 100 person-years (95% confidence interval [CI] 1.5-3.6) for event-driven PrEP, and 0.6 per 100 person-years (95% CI .1-2.3) for daily PrEP (adjusted incidence rate ratio 4.40, 95% CI 1.00-19.36, P = .050). Adequate adherence was lower with event-driven than daily PrEP (44.3% vs 74.9%, P < .001). Plasma drug concentrations were undetectable in 92 (97.9%) of the 94 measures taken for 23 participants who seroconverted. Only 1 participant had resistance to PrEP drugs.

CONCLUSIONS

HIV seroconversions mainly occurred in participants who chose event-driven PrEP. The study's data highlighted major difficulties with adherence to this regimen. Improving adherence to event-driven PrEP constitutes a major research and public health priority in this context.

Lessons Learned From the Implementation of a Pilot Study on Self-collected Specimen Return by Sexual Minority Men (Project Caboodle!): Qualitative Exploration

BACKGROUND

Self-collection of specimens at home and their return by mail might help reduce some of the barriers to HIV and bacterial sexually transmitted infection (STI) screening encountered by gay, bisexual, and other men who have sex with men (GBMSM). To evaluate the benefits and challenges of bringing this approach to scale, researchers are increasingly requesting GBMSM to return self-collected specimens as part of web-based sexual health studies. Testing self-collected hair samples for preexposure prophylaxis drug levels may also be a viable option to identify GBMSM who face adherence difficulties and offer them support.

OBJECTIVE

Project Caboodle! sought to evaluate the acceptability and feasibility of self-collecting at home and returning by mail 5 specimens (a finger-stick blood sample, a pharyngeal swab, a rectal swab, a urine specimen, and a hair sample) among 100 sexually active GBMSM in the United States aged between 18 and 34 years. In this manuscript, we aimed to describe the key lessons learned from our study's implementation and to present recommendations offered by participants to maximize the rates of self-collected specimen return.

METHODS

Following the specimen self-collection phase, a subset of 25 participants (11 who returned all 5 specimens, 4 who returned between 1 and 4 specimens, and 10 who did not return any specimens) was selected for in-depth interviews conducted via a videoconferencing platform. During the session, a semistructured interview guide was used to discuss the factors influencing decisions regarding returning self-collected specimens for laboratory processing. The transcripts were analyzed using template analysis.

RESULTS

University branding of web-based and physical materials instilled a sense of trust in participants and increased their confidence in the test results. Shipping the specimen self-collection box in plain unmarked packaging promoted discretion during transit and on its receipt. Using different colored bags with matching color-coded instructions to self-collect each type of specimen minimized the potential for confusion. Participants recommended including prerecorded instructional videos to supplement the written instructions, providing information on the importance of triple-site bacterial STI testing, and adding a reminder of the types of testing that would and would not be conducted on hair samples. Participants also suggested tailoring the specimen self-collection box to include only the tests that they might be interested in completing at that time, adding real-time videoconferencing to the beginning of the study to introduce the research team, and sending personalized reminders following the delivery of the specimen self-collection box.

CONCLUSIONS

Our results offer valuable insights into aspects that facilitated participant engagement in self-collected specimen return, as well as areas for potential improvement to maximize return rates. Our findings can help guide the design of future large-scale studies and public health programs for home-based HIV, bacterial STI, and preexposure prophylaxis adherence testing.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/13647.

Characteristics of Human Immunodeficiency Virus (HIV) Seroconversions in a Large Prospective Implementation Cohort Study of Oral HIV Preexposure Prophylaxis in Men Who Have Sex with Men (EPIC-NSW)

BACKGROUND

Most human immunodeficiency virus (HIV) seroconversions in people who have initiated preexposure prophylaxis (PrEP) occur in the context of insufficient adherence. We describe participants who seroconverted after being dispensed PrEP in a large PrEP implementation study in Australia.

METHODS

Expanded PrEP Implementation in Communities in New South Wales was an implementation study of daily oral PrEP in individuals aged ≥18 years at high risk for acquiring HIV. HIV seroconversions were defined as a positive HIV test by either antigen, antibody, or detectable HIV viral load after enrollment. Insufficient adherence, measured by dispensing logs or participant self-report, was defined as <4 PrEP doses per week.

RESULTS

A total of 9596 participants were enrolled and dispensed PrEP between 1 March 2016 and 30 April 2018; 30 were diagnosed with HIV by 31 March 2019. The median (interquartile range [IQR]) age was 31 (25-38) years, all identified as male, 29 (97%) identified as gay or homosexual, and 20 (69%) lived in a postcode with a low concentration of gay male residents. The median (IQR) days from first PrEP dispensing to diagnosis was 409 (347-656). There was no evidence that participants who seroconverted had been sufficiently adherent to PrEP. Nineteen (63%) participants who seroconverted were diagnosed with chlamydia, gonorrhoea, syphilis, or new hepatitis C infection. One participant had resistance to emtricitabine (M184V mutation) at diagnosis.

CONCLUSIONS

Participants who seroconverted were insufficiently adherent to PrEP despite being at high risk for acquiring HIV. Understanding the reasons for poor PrEP adherence in individuals who subsequently acquire HIV is critical to improving PrEP effectiveness.

Study Evaluating Self-Collected Specimen Return for HIV, Bacterial STI, and Potential Pre-Exposure Prophylaxis Adherence Testing Among Sexual Minority Men in the United States

Web-based HIV and sexually transmitted infection (STI) prevention studies are increasingly requesting gay, bisexual, and other men who have sex with men (GBMSM) to return self-collected specimens for laboratory processing. Some studies have solicited self-collected extragenital swabs for gonorrhea and chlamydia testing, but to date, none have solicited self-collected hair samples for pre-exposure prophylaxis (PrEP) adherence testing. Project Caboodle! offered 100 racially/ethnically diverse GBMSM aged 18 to 34 years residing across the United States a choice to self-collect at home and return by mail any of the following: a finger-stick blood sample (for HIV testing), a pharyngeal swab, a rectal swab and a urine specimen (for gonorrhea and chlamydia testing), and a hair sample (to visually assess its adequacy for PrEP drug level testing). Despite not incentivizing specimen return, 51% mailed back at least one type of specimen within 6 weeks (1% returned three specimens, 11% returned four specimens and 39% returned all five specimens). The majority of returned specimens were adequate for laboratory processing. Significantly more participants without a college education (p = .0003) and those who were working full-time or part-time (p = .0070) did not return any specimens. In addition, lower levels of HIV-related knowledge (p = .0390), STI-related knowledge (p = .0162), concern about contracting HIV (p = .0484), and concern about contracting STIs (p = .0108) were observed among participants who did not return any specimens. Self-collection of specimens holds promise as a remote monitoring strategy that could supplement testing in clinical settings, but a better understanding of why some GBMSM may choose to fully, partially, or not engage in this approach is warranted.

Am I Positive? Improving HIV Testing in the Era of Pre-Exposure Prophylaxis (PrEP) and Immediate Anti-Retroviral Therapy (iART) using Machine Learning

Background

Human immunodeficiency virus (HIV) testing is the first step in the HIV prevention cascade. The Centers for Disease Control and Prevention HIV laboratory diagnostic testing algorithm was developed before preexposure prophylaxis (PrEP) and immediate antiretroviral therapy (iART) became standards of care. PrEP and iART have been shown to delay antibody development and affect the performance of screening HIV assays. Quantitative results from fourth-generation HIV testing may be helpful to disambiguate HIV testing.

Methods

We retrospectively reviewed 38 850 results obtained at an urban, academic medical center. We assessed signal-to-cutoff (s/co) distribution among positive and negative tests, in patients engaged and not engaged in an HIV prevention program, and evaluated changes in patients with multiple results. Classification and regression tree (CART) analysis was used to determine a threshold cutoff, and logistic regression was used to identify predictors of true positive tests.

Results

Ninety-seven percent of patients with a negative HIV test had a result that was ≤0.2 s/co. For patients tested more than once, we found differences in s/co values did not exceed 0.2 s/co for 99.2% of results. CART identified an s/co value, 38.78, that in logistic regression on a unique validation cohort remained associated with the likelihood of a true-positive HIV result (odds ratio, 2.49).

Conclusions

Machine-learning methods may be used to improve HIV screening by automating and improving interpretations, incorporating them into robust algorithms, and improving disease prediction. Further investigation is warranted to confirm if s/co values combined with a patient's risk profile will allow for better clinical decision making for individuals on PrEP or eligible for iART.

Casting a Wide Net: HIV Drug Resistance Monitoring in Pre-Exposure Prophylaxis Seroconverters in the Global Evaluation of Microbicide Sensitivity Project

Global Evaluation of Microbicide Sensitivity projects in 4 countries demonstrated the feasibility of establishing an HIV drug resistance monitoring program for pre-exposure prophylaxis (PrEP). These projects will provide valuable information on seroconversions in the context of PrEP use and will serve to inform Ministries of Health and policy makers on the need for long-term surveillance approaches.

Background:

Evidence of HIV drug resistance (HIVDR) in individuals using oral pre-exposure prophylaxis (PrEP) who acquire HIV is limited to clinical trials and case studies. More data are needed to understand the risk of HIVDR with oral PrEP during PrEP rollout. Mechanisms to collect these data vary, and are dependent on cost, scale of PrEP distribution, and in-country infrastructure for the identification, collection, and testing of samples from PrEP seroconverters.

Methods:

The Global Evaluation of Microbicide Sensitivity (GEMS) project, in collaboration with country stakeholders, initiated HIVDR monitoring among new HIV seroconverters with prior PrEP use in Eswatini, Kenya, South Africa, and Zimbabwe. Standalone protocols were developed to assess HIVDR among a national sample of PrEP users. In addition, HIVDR testing was incorporated into existing demonstration projects for key populations.

Lessons learned:

Countries are supportive of conducting a time-limited evaluation of HIVDR during the early stages of PrEP rollout. As PrEP rollout expands, the need for long-term HIVDR monitoring with PrEP will need to be balanced with maintaining national HIV drug resistance surveillance for pretreatment and acquired drug resistance. Laboratory capacity is a common obstacle to setting up a monitoring system.

Conclusions:

Establishing HIV resistance monitoring within PrEP programs is feasible. Approaches to drug resistance monitoring may evolve as the PrEP programs mature and expand. The methods and implementation support offered by GEMS assisted countries in developing methods to monitor for drug resistance that best fit their PrEP program needs and resources.

Sex Hormone Therapy and Tenofovir Diphosphate Concentration in Dried Blood Spots: Primary Results of the Interactions Between Antiretrovirals And Transgender Hormones Study

BACKGROUND

Sex hormone and preexposure prophylaxis (PrEP) drug interactions among transgender women (TGW), transgender men (TGM), and cisgender men (CGM) are not fully understood.

METHODS

TGM and TGW on at least 6 months of stable sex hormone therapy containing testosterone or estradiol (respectively) were enrolled in a 4-week study of directly observed dosing of daily oral coformulated emtricitabine and tenofovir disoproxil fumarate (FTC/TDF). TFV-DP in dried blood spots and sex hormones in serum were measured at weekly intervals. TFV-DP was compared with 2- and 4-week samples from Directly Observed Therapy Dried Blood Spots (DOT-DBS) Study (NCT02022657).

RESULTS

From May 2017 to June 2018, 24 TGM and 24 TGW were enrolled. Testosterone (total and free) and estradiol concentrations were comparable before and after 4 weeks of PrEP use in TGM and TGW, respectively. Historical controls included 17 cisgender women (CGW) and 15 CGM. TFV-DP concentrations at week 4 were comparable between TGW and TGM (mean difference, -6%; 95% confidence interval [CI], -21% to 12%; P = .47), comparable between TGW and CGM (mean difference, -12%; 95% CI, -27% to 7%; P = .21) and were lower among TGM compared with CGW (mean difference, -23%; 95% CI, -36% to -7%; P = .007). All persons in all groups were projected to reach the TFV-DP threshold that has been associated with high protection from human immunodeficiency virus.

CONCLUSIONS

CGM, TGM, and TGW had comparable TFV-DP concentrations in dried blood spots after 4 weeks of directly observed daily FTC/TDF PrEP use. Serum hormone concentrations were not affected by FTC/TDF PrEP use.

CLINICAL TRIALS REGISTRATION

NCT04050371.

High Acceptability of Donating Hair and Other Biological Samples for Research Among People Living with HIV in an Outpatient Clinic in Lagos, Nigeria

Willingness to donate hair samples is a rate-limiting step for assaying antiretroviral (ARV) concentrations in hair, an emerging technique for HIV prevention and treatment monitoring. We surveyed ethnically diverse Nigerians to determine their willingness to donate hair for biomedical research. A cross-sectional survey of people living with HIV on ARV therapy (ART) was conducted at the HIV clinic of Nigerian Institute of Medical Research, using systematic sampling. The researcher-administered questionnaire was designed to capture sociodemographic data, length of time on ART, and willingness to donate hair. Univariate analysis was performed on sociodemographic characteristics, and independent-samples t-test and chi-square tests were used for bivariate analysis. Multivariable logistic regression analysis was performed to assess factors associated with willingness to donate hair samples, with a significance level of 0.05. Of the 398 participants enrolled in the study, 258 (64.8%) were female, the average age was 40 years (±9.8), and the average time spent on ART was 7.3 years (±4.2). More than half (64.8%) of the respondents were willing to donate hair samples for biomedical research and they were 1.5 times more likely to donate hair than blood. For one-third of the participants, the anticipated benefit from the eventual research findings was the primary motivation to donate hair samples. Fear of use of hair for rituals was the most common stated reason for unwillingness to donate hair samples (21.2%). In an ethnically diverse, urban-based Nigerian study population, nearly two-thirds of the participants were willing to donate hair samples for biomedical research. These findings support the feasibility of hair sampling for future HIV clinical research conducted within Nigeria.

Long-term protection from HIV infection with oral HIV pre-exposure prophylaxis in gay and bisexual men: findings from the expanded and extended EPIC-NSW prospective implementation study

BACKGROUND

Daily pre-exposure prophylaxis (PrEP) is effective in preventing HIV, but few long-term data are available on effectiveness and adherence in real-world settings. Here, we report trends in HIV incidence over 3 years in individuals at high risk who were prescribed PrEP in New South Wales (NSW), as well as adherence before the transition to subsidised PrEP.

METHODS

Expanded PrEP Implementation in Communities-New South Wales (EPIC-NSW) was a pragmatic, prospective, single-arm, implementation study of daily, oral PrEP in 31 sites (sexual health clinics, general practices, and a hospital) in NSW, Australia. Eligible participants were HIV-negative adults (aged ≥18 years) who were at high risk of HIV infection as defined in local PrEP guidelines. Participants were prescribed coformulated (once-daily, oral tablet) tenofovir disoproxil fumarate (300 mg) and emtricitabine (200 mg) as HIV PrEP and were followed up with HIV testing, sexually transmitted infection testing, and PrEP dispensing. Originally planned for 3700 participants followed for 1 year, the study was expanded so that all eligible participants in the state could obtain PrEP and extended until publicly subsidised PrEP became available in Australia. The primary outcome was new HIV infection among all participants who were dispensed PrEP at least once and had at least one follow-up HIV test result. Adherence was estimated by medication possession ratio (MPR), defined as the proportion of PrEP pills dispensed in 90 days, assuming daily dosing. This study is registered with ClinicalTrials.gov, NCT02870790.

FINDINGS

Between March 1, 2016, and April 30, 2018, we enrolled 9709 participants. 9596 participants were dispensed PrEP, of whom 9448 (98·3%) were gay or bisexual men. Participants were followed up until March 31, 2019, with at least one follow-up HIV test available in 9520 (99·2%) participants. Mean MPR declined from 0·93 to 0·64 from the first to the ninth quarter. There were 30 HIV seroconversions over 18 628 person-years, an incidence of 1·61 per 1000 person-years (95% CI 1·13-2·30). Being younger, living in a postcode with fewer gay men, reporting more risk behaviours at baseline, and having an MPR of less than 0·6 were each univariately associated with increased HIV incidence. In the final year of follow-up, when PrEP was mostly purchased rather than provided free by the study, HIV incidence remained low at 2·24 per 1000 person-years (1·46-3·44).

INTERPRETATION

HIV incidence remained low over up to 3 years of follow-up, including during a transition from study-provided to publicly subsidised PrEP. In a setting of affordable PrEP and associated health-care services, very low HIV incidence of 1 to 2 per 1000 person-years can be maintained in gay and bisexual men who were previously at high risk.

FUNDING

New South Wales Ministry of Health, Australian Capital Territory Health Directorate, Gilead Sciences.

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.

Infection with antiretroviral-susceptible HIV in an individual adherent to pre-exposure prophylaxis: strategies for treatment initiation

HIV pre-exposure prophylaxis (PrEP) is effective at preventing sexual acquisition of HIV, and failures in clinical trials are largely attributable to medication nonadherence. We report here a case of infection with a fully susceptible strain of HIV in an individual adherent to PrEP as demonstrated by pharmacy records and intracellular tenofovir diphosphate levels. At diagnosis, the viral load was 90 copies/mL precluding initial genotype testing due to low copy number. While PrEP failure is rare, this case underscores the importance of regular HIV testing for patient on PrEP and prompts discussion regarding the approach to treatment following failure where an initial genotype is not yet available or not possible due to low viral load. Few other case reports of PrEP failure exist in the literature and approaches to treatment varied widely. We suggest the initial viral copy number may guide next steps and discuss the risks and benefits of stopping PrEP, escalating therapy with integrase inhibitors or boosted protease inhibitors, or switching to non-nucleoside antiretroviral treatment regimens.

Raman-based metabonomics unravels metabolic changes related to a first-line tenofovir-based treatment in a small cohort of South African HIV-infected patients

In addition to immunological disorders, human immunodeficiency virus (HIV) also causes metabolic abnormalities. Though successful in viral suppression and immune restoration, continued use of antiretroviral therapy (ART) has also been linked to the development of several metabolic ailments. Currently, the only clinical markers used to manage and monitor the development of HIV-induced metabolic disorders, disease progression as well as observing individual's response to antiviral treatment are CD4 count, viral loads and several other single variable colometric assays. Despite the common use of these clinical markers, these markers remain unreliable and limited in the ability to monitor the development of metabolic disorders as well as monitor treatment response. Given these limitations, it is imperative to discover and develop reliable biological markers for overall HIV disease management. Here, Raman spectroscopy was used to profile metabolic changes in the plasma of 22 HIV⁺ receiving a first-line tenofovir-based combination antiretroviral therapy compared to their 8 HIV⁺ ART^- and 10 HIV^- counterparts. Multivariate statistical analysis was performed in order to classify the samples into their respective groups and to identify significantly altered metabolites between the control and experimental groups. Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) discriminant analysis identified significant differences (p < 0.05) in 9 different metabolites. Alterations were identified in spectral regions associated with glucose (1124 cm^-1), lipids/phospholipids (1116 cm^-1, 1098 cm^-1, 1077 cm^-1), proteins (1120 cm^-1), nucleic acids (1081 cm^-1) and phenylalanine (1103 cm^-1). Pathway analysis also revealed 3 significantly altered pathways. This study presented the reproducible nature of Raman spectroscopy in distinguishing between HIV-infected (treated and untreated) and uninfected blood plasma and allowed for the detection and identification of treatment induced metabolite changes. The results obtained in the study may, therefore, give insights into understanding the metabolic effect of HIV therapy.

Point-of-care and Near Real-time Testing for Antiretroviral Adherence Monitoring to HIV Treatment and Prevention

PURPOSE OF REVIEW

In this report, we review the need for point-of-care (POC) or near real-time testing for antiretrovirals, progress in the field, evidence for guiding implementation of these tests globally, and future directions in objective antiretroviral therapy (ART) or pre-exposure prophylaxis (PrEP) adherence monitoring.

RECENT FINDINGS

Two cornerstones to end the HIV/AIDS pandemic are ART, which provides individual clinical benefits and eliminates forward transmission, and PrEP, which prevents HIV acquisition with high effectiveness. Maximizing the individual and public health benefits of these powerful biomedical tools requires high and sustained antiretroviral adherence. Routine monitoring of medication adherence in individuals receiving ART and PrEP may be an important component in interpreting outcomes and supporting optimal adherence. Existing practices and subjective metrics for adherence monitoring are often inaccurate or unreliable and, therefore, are generally ineffective for improving adherence. Laboratory measures of antiretroviral concentrations using liquid chromatography tandem mass spectrometry have been utilized in research settings to assess medication adherence, although these are too costly and resource-intensive for routine use. Newer, less costly technologies such as antibody-based methods can provide objective drug-level measurement and may allow for POC or near-patient adherence monitoring in clinical settings. When coupled with timely and targeted counseling, POC drug-level measures can support adherence clinic-based interventions to ART or PrEP in near real time.

HIV incidence after pre-exposure prophylaxis initiation among women and men at elevated HIV risk: A population-based study in rural Kenya and Uganda

BACKGROUND

Oral pre-exposure prophylaxis (PrEP) is highly effective for HIV prevention, but data are limited on HIV incidence among PrEP users in generalized epidemic settings, particularly outside of selected risk groups. We performed a population-based PrEP study in rural Kenya and Uganda and sought to evaluate both changes in HIV incidence and clinical and virologic outcomes following seroconversion on PrEP.

METHODS AND FINDINGS

During population-level HIV testing of individuals ≥15 years in 16 communities in the Sustainable East Africa Research in Community Health (SEARCH) study (NCT01864603), we offered universal access to PrEP with enhanced counseling for persons at elevated HIV risk (based on serodifferent partnership, machine learning-based risk score, or self-identified HIV risk). We offered rapid or same-day PrEP initiation and flexible service delivery with follow-up visits at facilities or community-based sites at 4, 12, and every 12 weeks up to week 144. Among participants with incident HIV infection after PrEP initiation, we offered same-day antiretroviral therapy (ART) initiation and analyzed HIV RNA, tenofovir hair concentrations, drug resistance, and viral suppression (<1,000 c/ml based on available assays) after ART start. Using Poisson regression with cluster-robust standard errors, we compared HIV incidence among PrEP initiators to incidence among propensity score-matched recent historical controls (from the year before PrEP availability) in 8 of the 16 communities, adjusted for risk group. Among 74,541 individuals who tested negative for HIV, 15,632/74,541 (21%) were assessed to be at elevated HIV risk; 5,447/15,632 (35%) initiated PrEP (49% female; 29% 15-24 years; 19% in serodifferent partnerships), of whom 79% engaged in ≥1 follow-up visit and 61% self-reported PrEP adherence at ≥1 visit. Over 7,150 person-years of follow-up, HIV incidence was 0.35 per 100 person-years (95% confidence interval [CI] 0.22-0.49) among PrEP initiators. Among matched controls, HIV incidence was 0.92 per 100 person-years (95% CI 0.49-1.41), corresponding to 74% lower incidence among PrEP initiators compared to matched controls (adjusted incidence rate ratio [aIRR] 0.26, 95% CI 0.09-0.75; p = 0.013). Among women, HIV incidence was 76% lower among PrEP initiators versus matched controls (aIRR 0.24, 95% CI 0.07-0.79; p = 0.019); among men, HIV incidence was 40% lower, but not significantly so (aIRR 0.60, 95% CI 0.12-3.05; p = 0.54). Of 25 participants with incident HIV infection (68% women), 7/25 (28%) reported taking PrEP ≤30 days before HIV diagnosis, and 24/25 (96%) started ART. Of those with repeat HIV RNA after ART start, 18/19 (95%) had <1,000 c/ml. One participant with viral non-suppression was found to have transmitted viral resistance, as well as emtricitabine resistance possibly related to PrEP use. Limitations include the lack of contemporaneous controls to assess HIV incidence without PrEP and that plasma samples were not archived to assess for baseline acute infection.

CONCLUSIONS

Population-level offer of PrEP with rapid start and flexible service delivery was associated with 74% lower HIV incidence among PrEP initiators compared to matched recent controls prior to PrEP availability. HIV infections were significantly lower among women who started PrEP. Universal HIV testing with linkage to treatment and prevention, including PrEP, is a promising approach to accelerate reductions in new infections in generalized epidemic settings.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01864603.

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.

Approaches to Objectively Measure Antiretroviral Medication Adherence and Drive Adherence Interventions

PURPOSE OF REVIEW

Traditional methods to assess antiretroviral adherence, such as self-report, pill counts, and pharmacy refill data, may be inaccurate in determining actual pill-taking to both antiretroviral therapy (ART) or pre-exposure prophylaxis (PrEP). HIV viral loads serve as surrogates of adherence on ART, but loss of virologic control may occur well after decreases in adherence and viral loads are not relevant to PrEP.

RECENT FINDINGS

Pharmacologic measures of adherence, electronic adherence monitors, and ingestible electronic pills all serve as more objective metrics of adherence, surpassing self-report in predicting outcomes. Pharmacologic metrics can identify either recent adherence or cumulative adherence. Recent dosing measures include antiretroviral levels in plasma or urine, as well as emtricitabine-triphosphate in dried blood spots (DBS) for those on tenofovir-emtricitabine-based therapy. A urine tenofovir test has recently been developed into a point-of-care test for bedside adherence monitoring. Cumulative adherence metrics assess adherence over weeks to months and include measurement of tenofovir-diphosphate in peripheral blood mononuclear cells or DBS, as well as ART levels in hair. Electronic adherence monitors and ingestible electronic pills can track pill bottle openings or medication ingestion, respectively. New and objective approaches in adherence monitoring can be used to detect nonadherence prior to loss of prevention efficacy or virologic control with PrEP or ART, respectively.

A review of reported cases of HIV pre-exposure prophylaxis failure with resultant breakthrough HIV infections

OBJECTIVES

Early randomized controlled trials (RCTs) have confirmed high efficacy of pre-exposure prophylaxis (PrEP) for preventing HIV infection in men who have sex with men (MSM) with high HIV exposure risk. Nevertheless, some PrEP failure cases have been reported despite adequate drug adherence. This review aims to summarize the common features of PrEP failure cases and discuss the implications of upscaling PrEP programmes.

METHODS

A search based on articles and clinical trials was conducted through Medline and OVID, with keywords for accessing publications reporting 'true' PrEP failure in the presence of documented adherence to daily regimen of co-formulated tenofovir disoproxil fumarate/emtricitabone.

RESULTS

Ten cases of 'true' PrEP failure were identified, all of which were preceded by continued practice of condomless anal sex, despite documented adherence. Dried blood spot and/or hair analyses provided supporting evidence of adherence in eight cases. There was strong association of PrEP failure with recurrent or multiple sexually transmitted diseases and infection with resistant HIV viruses. Seroconversion was usually atypical or delayed because of significantly suppressed viral load, making diagnosis a clinical challenge.

DISCUSSION

Although it is uncommon, 'true' PrEP failure can occur in a real-world situation, contrary to the outcome of early RCTs. Failure to identify HIV infection while on PrEP can potentially lead to the emergence of drug-resistant virus. To achieve effective HIV prevention, PrEP programmes should emphasize safer sexual practice in addition to drug adherence. Early identification of PrEP failure is crucial, which requires the development of highly sensitive assays and their clinical application.

Implementing a Status-Neutral Approach to HIV in the Asia-Pacific

PURPOSE OF REVIEW

Globally, "undetectable equals untransmittable (U=U)" and "pre-exposure prophylaxis (PrEP)" have become crucial elements in HIV treatment and prevention programs. We reviewed the implementation of U=U and PrEP among countries in the Asia-Pacific region.

RECENT FINDINGS

U=U and PrEP uptakes were limited and slow in the Asia-Pacific. Inadequate knowledge among health care practitioners and pervasive stigma towards individuals living with HIV and their sexual lives are key barriers for the integration of U=U into clinical practice. Paternalistic and hierarchical health care systems are major obstacles in PrEP implementation and scale-up. Countries with the most advanced PrEP implementation all use community-based, nurse-led, and key population-led service delivery models. To advance U=U and PrEP in the Asia-Pacific, strategies targeting changes to practice norm through wide-scale stakeholders' training and education, making use of online health care professional influencers, and utilizing financial mechanism should be further explored through implementation research.

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.

Tail-phase safety, tolerability, and pharmacokinetics of long-acting injectable cabotegravir in HIV-uninfected adults: a secondary analysis of the HPTN 077 trial

BACKGROUND

Long-acting injectable cabotegravir is a novel integrase inhibitor currently in advanced clinical development for HIV prevention and treatment. We aimed to assess the terminal phase pharmacokinetics and safety of long-acting injectable cabotegravir in participants included in the HPTN 077 trial.

METHODS

HPTN 077 was a multicentre, double-blind, randomised, placebo-controlled phase 2a trial done at eight sites in Brazil, Malawi, South Africa, and the USA. Participants (aged 18-65 years), who were HIV-uninfected and at low-risk for HIV, were randomly assigned (3:1) to long-acting injectable cabotegravir (800 mg given three times at 12 week intervals or 600 mg given five times, administered at one 4 week interval, and every 8 weeks thereafter) or placebo. Participants were followed up to 76 weeks after final injection. In a prespecified analysis of secondary and exploratory outcomes, we assessed the safety, measured by the proportion of participants with grade 2 or worse adverse events, and pharmacokinetics, measured by apparent terminal phase half-life (t_1/2app) and estimated time to lower limit of quantification (LLOQ) of long-acting injectable cabotegravir during the injection phase (defined as the time between first injection and 12 weeks or 8 weeks after the last injection in cohort 1 or cohort 2 respectively) and tail phase (defined as the time between final injection and 52-76 weeks post-final injection). Safety was analysed in all participants who received at least one injection. Pharmacokinetic analyses included all participants who had received at least one injection and had at least three cabotegravir measurements higher than the LLOQ after the final injection. Pharmacokinetic outcomes were estimated using non-compartmental methods. The trial is completed, and was registered with ClinicalTrials.gov, NCT02178800.

FINDINGS

Between Feb 9, 2015, and May 27, 2016, 177 participants (134 participants in the cabotegravir group [74 participants in cohort 1; 60 participants in cohort 2] and 43 participants in the placebo group [25 participants in cohort 1; 18 participants in cohort 2) were enrolled and received at least one injection and thus were included in the safety analysis. The incidence of grade 2 or worse adverse events was significantly lower during the tail phase than the injection phase (p<0·0001). At 52-60 weeks after final injection, nine (23%) of 40 male participants had detectable cabotegravir concentrations and at week 76, four (13%) of 30 male participants had detectable cabotegravir concentrations compared with 52 (63%) of 82 female participants and 27 (42%) of 64 female participants at the same timepoints. The median time from the last injection to the time when cabotegravir concentration decreased below the LLOQ was 43·7 weeks (IQR 31·1-66·6; range 20·4-152·5) for male participants and 67·3 weeks (29·1-89·6; 17·7-225·5) for female participants (p=0·0003). t_1/2app was longer for female participants than male participants (geometric mean fold-change 1·33, 95% CI 1·06-1·68; p=0·014), and longer for participants with a high body-mass index (BMI) than those with a low BMI (1·31, 1·06-1·63; p=0·015).

INTERPRETATION

The clinical significance of the long pharmacokinetic tail of cabotegravir observed in female participants compared with male participants, and those with higher BMI compared with a lower BMI, need to be addressed in future trials.

FUNDING

National Institute of Allergy and Infectious Diseases.

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.

Tenofovir concentrations in hair strongly predict virologic suppression in breastfeeding women

BACKGROUND

Antiretroviral treatment (ART) adherence is often suboptimal in the perinatal period. We measured hair tenofovir (TFV) concentrations as a metric of adherence in postpartum women to understand patterns and predictors of adherence throughout this critical period. In addition, we examined the association between hair TFV concentrations and virologic outcomes.

METHODS

Between 12/2012 and 09/2016, hair samples were collected longitudinally from delivery through breastfeeding from women on ART in the Promoting Maternal and Infant Survival Everywhere study (NCT01061151) in sub-Saharan Africa. Hair TFV levels were measured using validated methods. Using generalized estimating equations, we estimated the association between hair TFV levels and virologic suppression (<400 copies/ml) over time and assessed predictors of hair TFV levels.

RESULTS

Hair TFV levels were measured at 370 visits in 71 women from delivery through a median of 14 months (interquartile range 12-15) of breastfeeding. Levels ranged from below detection (0.002) to 1.067 ng/mg (geometric mean: 0.047). After at least 90 days on ART, 69 women had at least one viral load measured (median 5 measures, range 1-9); 18 (26%) experienced viremia at least once. Each doubling of TFV level more than doubled odds of concurrent virologic suppression [odds ratio 2.35, 95% confidence interval (CI): 1.44-3.84, P = 0.0006] and was associated with 1.43 times the odds of future suppression (95% CI: 0.75-2.73, P = 0.28). Relative to the first 3 months after delivery, hair levels were highest in months 6-12 (1.42-fold higher, 95% CI: 1.09-1.85, P = 0.01).

CONCLUSION

Hair TFV levels strongly predicted concurrent virologic suppression among breastfeeding women. Objective adherence metrics can supplement virologic monitoring to optimize treatment outcomes in this important transition period.

Willingness to Donate Hair Samples for Research Among People Living with HIV/AIDS Attending a Tertiary Health Facility in Ibadan, Nigeria

The use of hair samples in biomedical research is a rapidly growing field. High acceptability rates for hair collection have been demonstrated in multiple settings. Each setting may have unique issues and, to our knowledge, no previous study has assessed the acceptability of hair sampling for HIV-related research in Nigeria. This study aimed to assess the willingness to donate hair for research among people living with HIV (PLWH). A cross-sectional study was conducted among 381 PLWH in a tertiary institution in Southwest Nigeria, using convenience sampling. An interviewer-administered questionnaire was used to collect data from consenting participants, including a question on willingness to donate hair for research. The mean age of respondents was 42.1 ± 10.5 years and more than three-quarters of the respondents were females. Two hundred and eighty-eight (75.8%) respondents had at least a tertiary education. Only 51.4% of the respondents were willing to donate their hair for research. Possible sample diversion for rituals was the major (60.5%) reason cited for unwillingness to donate hair. In multivariate analysis, respondents with primary education or less exhibited a trend toward being more willing to donate hair than those with secondary education or more (p = .091). Muslims were 1.7 times more willing to donate hair than Christians even after adjusting for other demographic covariates (95% confidence interval: 1.11-2.72); p = .016. There is a moderate willingness to donate hair for research among our population of PLWH in Nigeria. These results underscore the importance of cultural sensitivity and community education when introducing innovative HIV research techniques to new settings.

Update on HIV Preexposure Prophylaxis: Effectiveness, Drug Resistance, and Risk Compensation

PURPOSE OF REVIEW

In 2019, the US government launched an initiative to decrease new HIV infections by 90% over the next decade. Studies have demonstrated the efficacy of HIV preexposure prophylaxis (PrEP) for high-risk populations, and the United States Preventative Services Task Force has issued a grade A recommendation for PrEP, indicating substantial net benefit. However, questions have been raised about the effectiveness of PrEP in clinical settings and whether PrEP use might promote antiretroviral drug resistance and increased sexual risk behaviors, which could increase transmission of bacterial sexually transmitted infections. In this narrative review, we summarize recent evidence of the effectiveness of PrEP when provided in clinical and community settings, the emergence of antiretroviral drug resistance during PrEP use, and associations between PrEP use and increased sexual risk behaviors. We also review novel PrEP modalities that are being developed to optimize PrEP acceptability, adherence, and effectiveness.

RECENT FINDINGS

Studies suggest that PrEP is effective when provided in clinical settings. However, PrEP uptake and impact have been limited in the USA thus far, and major disparities in access to PrEP exist. In addition, there is evidence that drug resistance can occur with PrEP use, particularly with inadvertent PrEP use during undiagnosed acute HIV infection. Risk compensation can also occur with PrEP use and has been associated with increased sexually transmitted infections. Promising new modalities for PrEP could expand options. PrEP has strong potential to decrease HIV incidence. However, disparities in access must be addressed to ensure equity and impact for PrEP. While drug resistance and risk compensation can occur with PrEP use, these are not valid reasons to withhold PrEP from patients given its substantial protective benefits.

A generalizable method for estimating duration of HIV infections using clinical testing history and HIV test results

OBJECTIVE

To determine the precision of new and established methods for estimating duration of HIV infection.

DESIGN

A retrospective analysis of HIV testing results from serial samples in commercially available panels, taking advantage of extensive testing previously conducted on 53 seroconverters.

METHODS

We initially investigated four methods for estimating infection timing: method 1, 'Fiebig stages' based on test results from a single specimen; method 2, an updated '4th gen' method similar to Fiebig stages but using antigen/antibody tests in place of the p24 antigen test; method 3, modeling of 'viral ramp-up' dynamics using quantitative HIV-1 viral load data from antibody-negative specimens; and method 4, using detailed clinical testing history to define a plausible interval and best estimate of infection time. We then investigated a 'two-step method' using data from both methods 3 and 4, allowing for test results to have come from specimens collected on different days.

RESULTS

Fiebig and '4th gen' staging method estimates of time since detectable viremia had similar and modest correlation with observed data. Correlation of estimates from both new methods (3 and 4), and from a combination of these two ('two-step method') was markedly improved and variability significantly reduced when compared with Fiebig estimates on the same specimens.

CONCLUSION

The new 'two-step' method more accurately estimates timing of infection and is intended to be generalizable to more situations in clinical medicine, research, and surveillance than previous methods. An online tool is now available that enables researchers/clinicians to input data related to method 4, and generate estimated dates of detectable infection.

Acceptability and Feasibility of Self-Collecting Biological Specimens for HIV, Sexually Transmitted Infection, and Adherence Testing Among High-Risk Populations (Project Caboodle!): Protocol for an Exploratory Mixed-Methods Study

BACKGROUND

Men who have sex with men (MSM) in the United States experience a disproportionate burden of HIV and bacterial sexually transmitted infections (STIs), such as gonorrhea and chlamydia. Screening levels among MSM remain inadequate owing to barriers to testing such as stigma, privacy and confidentiality concerns, transportation issues, insufficient clinic time, and limited access to health care. Self-collection of specimens at home and their return by mail for HIV and bacterial STI testing, as well as pre-exposure prophylaxis (PrEP) adherence monitoring, could be a resource-efficient option that might mitigate some of these barriers.

OBJECTIVE

Project Caboodle! is a mixed-methods study that explores the acceptability and feasibility of self-collecting and returning a bundle of 5 different specimens for HIV and bacterial STI testing, as well as PrEP adherence monitoring, among sexually active HIV-negative or unknown status MSM in the United States aged 18 to 34 years.

METHODS

Participants will be recruited using age, race, and ethnicity varied advertising on social networking websites and mobile gay dating apps. In Phase 1, we will send 100 participants a box containing materials for self-collecting and potentially returning a finger-stick blood sample (for HIV testing), pharyngeal swab, rectal swab, and urine specimen (for gonorrhea and chlamydia testing), and hair sample (to assess adequacy for potential PrEP adherence monitoring). Specimen return will not be incentivized, and participants can choose to mail back all, some, or none of the specimens. Test results will be delivered back to participants by trained counselors over the phone. In Phase 2, we will conduct individual in-depth interviews using a video-based teleconferencing software (VSee) with 32 participants from Phase 1 (half who returned all specimens and half who returned some or no specimens) to examine attitudes toward and barriers to completing various study activities.

RESULTS

Project Caboodle! was funded in May 2018, and participant recruitment began in March 2019. The processes of designing a study logo, creating advertisements, programming Web-based surveys, and finalizing step-by-step written instructions accompanied by color images for specimen self-collection have been completed. The boxes containing 5 self-collection kits affixed with unique identification stickers are being assembled, and shipping procedures (for mailing out boxes to participants and for specimen return by participants using prepaid shipping envelopes) and payment procedures for completing the surveys and in-depth interviews are being finalized.

CONCLUSIONS

Self-collection of biological specimens at home and their return by mail for HIV and bacterial STI testing, as well as PrEP adherence monitoring, might offer a practical and convenient solution to improve comprehensive prevention efforts for high-risk MSM. The potentially reduced time, expense, and travel associated with this approach could facilitate a wider implementation of screening algorithms and remote monitoring strategies.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/13647.