Heterosexual HIV-1 infectiousness and antiretroviral use: systematic review of prospective studies of discordant couples

Effectiveness of Frequent Viral Load Testing Plus Additional Interventions to Prevent HIV Transmission in Heterosexual, Serodiscordant Couples - Yunnan Province, China, 2019-2021

What is already known about this topic?

HIV transmission among serodiscordant couples remains a persistent issue in China. However, the practice of combining counseling with antiretroviral therapies (ART) to enhance ART adherence is not widely implemented or recommended in Chinese health guidelines.

What is added by this report?

This randomized controlled trial suggests that increased follow-up, counseling, and awareness of HIV risk can enhance ART compliance, thereby maximizing treatment efficacy.

What are the implications for public health practice?

Early testing and counseling of serodiscordant couples, following the identification of a human immunodeficiency virus (HIV) positive spouse, is crucial for initiating ART and reducing the risk of seroconversion in the uninfected partner. Implementing a combination of ART and adjunct counseling in China is advisable.

Attitudes Toward and Experiences With Discussing Pre-exposure Prophylaxis With Sexual Partners Among US Adolescents and Young Adults Living With HIV

PURPOSE

Sexual partners of youth living with HIV are a key population for pre-exposure prophylaxis (PrEP). Among youth engaged in HIV medical care, we examined awareness of PrEP and experiences with and attitudes toward discussing PrEP with sexual partners.

METHODS

We recruited 25 15-24-year olds from an adolescent/young adult HIV clinic to complete individual interviews. Interviews assessed demographics, PrEP knowledge, sexual behaviors, and experiences with, intentions toward, barriers, and facilitating factors to discussing PrEP with partners. Transcripts were analyzed using framework analysis.

RESULTS

Mean age was 18.2 years. Twelve participants were cis-female, 11 cis-male, and two transgender female. Seventeen participants (68%) identified as Black, non-Hispanic. Nineteen acquired HIV sexually. Of 22 participants who had ever had sex, eight reported condomless sex in the prior 6 months. Most youth (17/25) were aware of PrEP. Only 11 participants had discussed PrEP with a partner; 16 reported high intention to discuss PrEP with future partners. Barriers to discussing PrEP with partners included participant-related barriers (i.e., discomfort disclosing HIV status), partner-related barriers (i.e., not open to or unfamiliar with PrEP), relationship-related barriers (i.e., new relationship, lack of trust), and stigma about HIV. Facilitating factors included positive relationship factors, educating partners about PrEP, and partners being receptive to learning about PrEP.

DISCUSSION

Although many youth living with HIV were aware of PrEP, fewer had discussed PrEP with a partner. PrEP use by partners of these youth may be improved by educating all youth about PrEP and offering opportunities for partners to meet with clinicians to discuss PrEP.

Lived Experience and Risk Reduction Behaviors Among Sero-Negative Discordant Male Partners Living with HIV-Positive Women in Addis Ababa, Ethiopia, 2019: A Qualitative Phenomenological Study

Objective

This study aimed to explore lived experience and risk reduction behaviors among sero-negative, discordant male partners living with HIV-positive women in Addis Ababa, Ethiopia, 2019.

Methods

A phenomenological study was conducted to explore lived experience and risk reduction behaviors. The study participants were purposively selected 13 sero-negative male partners living with HIV-positive women. An in-depth interview was used to explore important information. A semi-structured interview guide was used to execute the in-depth interview. The in-depth interview was analyzed thematically through the support of ATLAS-ti 7 software.

Results

Scientific explanation of discordant result is not well understood rather, it is associated with religious, cultural, natural resistance, and passive carrier explanations. Sero-negative partners faced several challenges and lived dilemmatic life related to partner mood or behavioral change, maintaining the marital relationship, the desire of child, psychosocial, sexual life, and lack of support system. Risk reduction behaviors like condom use, safe sex practice, preventing sexually transmitted infection, avoiding substance use, continuous checkup and follow-up were not well reflected in their lived experience and were poorly understood. Personalized use of sharp materials to avoid blood contact and support of a partner in the proper use of ART drugs were positively reported risk reduction behaviors.

Conclusion

Sero-negative partners need special attention just as HIV-positive partners in couples with the discordant result. Life suffering is not limited to HIV-positive partners, rather sero-negative partners also faced several challenges and dilemmatic life. HIV transmission risk reduction behavior is not well established and understood.

Human Immunodeficiency Virus transmission by HIV Risk Group and Along the HIV Care Continuum: A Contrast of 6 US Cities

BACKGROUND

Understanding the sources of HIV transmission provides a basis for prioritizing HIV prevention resources in specific geographic regions and populations. This study estimated the number, proportion, and rate of HIV transmissions attributable to individuals along the HIV care continuum within different HIV transmission risk groups in 6 US cities.

METHODS

We used a dynamic, compartmental HIV transmission model that draws on racial behavior-specific or ethnic behavior-specific and risk behavior-specific linkage to HIV care and use of HIV prevention services from local, state, and national surveillance sources. We estimated the rate and number of HIV transmissions attributable to individuals in the stage of acute undiagnosed HIV, nonacute undiagnosed HIV, HIV diagnosed but antiretroviral therapy (ART) naïve, off ART, and on ART, stratified by HIV transmission group for the 2019 calendar year.

RESULTS

Individuals with undiagnosed nonacute HIV infection accounted for the highest proportion of total transmissions in every city, ranging from 36.8% (26.7%-44.9%) in New York City to 64.9% (47.0%-71.6%) in Baltimore. Individuals who had discontinued ART contributed to the second highest percentage of total infections in 4 of 6 cities. Individuals with acute HIV had the highest transmission rate per 100 person-years, ranging from 76.4 (58.9-135.9) in Miami to 160.2 (85.7-302.8) in Baltimore.

CONCLUSION

These findings underline the importance of both early diagnosis and improved ART retention for ending the HIV epidemic in the United States. Differences in the sources of transmission across cities indicate that localized priority setting to effectively address diverse microepidemics at different stages of epidemic control is necessary.

Antiretroviral Treatment Sharing among Female sex Workers Living with HIV in eThekwini (Durban), South Africa: Drivers and Implications for Treatment Success

In South Africa, 62% of female sex workers (FSW) are estimated to be living with HIV. Qualitative research indicates that FSW share antiretroviral therapy (ART) with peers to surmount treatment barriers. We quantitatively described ART sharing, its correlates, and its relationship with viral suppression (VS) among FSW living with HIV in eThekwini, South Africa. Among FSW on ART (n = 890), 30% ever shared (gave and/or received) ART. Sharing ART was more likely among those with higher levels of alcohol use, illicit drug use, depression severity, and physical/sexual violence in the adjusted model. There was a positive, dose-response relationship between number of pills given to peers in the last 30 days and VS likelihood (aPR: 1.05, 95% CI: 1.02, 1.08; p < 0.01). Giving pills may strengthen peer relationships, which may facilitate ART adherence. ART distribution through peer networks holds promise as a context-appropriate intervention for improving ART adherence among FSW in this setting.

Barriers to HIV treatment adherence among adults living with HIV in the eastern Dominican Republic

Despite access to nationally supplied antiretroviral treatment, viral load suppression rates remain suboptimal in the Dominican Republic. Counseling and support services are available but mainly targeted to those identified as having the most need. At Clínica de Familia La Romana (CFLR) in La Romana, all patients undergo a structured baseline interview including exploration of expected barriers to care. We conducted a retrospective cohort study of a random sample of patients at CFLR with treatment initiation between 1 January 2015 and 1 December 2017 to determine if self-identified barriers to HIV care predict viral load suppression. Viral load suppression occurred in 63% of the 203 patients evaluated. Lack of food (n = 19) was significantly associated with lack of viral suppression (OR 3.0, 95% CI 1.14-7.87). Nondisclosure of HIV status (n = 24) showed evidence for a protective effect (OR 0.33; 95% CI 0.11-1.0). Further steps should be taken to address food insecurity as well as to understand associated barriers to care among individuals with food insecurity.

Adherence and Its Associated Factors Among Adult HIV-Infected Patients on Antiretroviral Therapy in South Western Ethiopia, 2020

BACKGROUND

Good adherence to antiretroviral therapy (ART) suppresses the viral load, reconstitutes the immune system, and decreases opportunistic infections among HIV-positive patients. However, adherence to ART is still challenging in developing countries such as Ethiopia. The study, therefore, aimed to assess adherence and its associated factors among HIV-positive patients on ART in southern Ethiopia in 2020.

MATERIALS AND METHODS

A cross-sectional study was conducted among 329 randomly selected participants. A structured questionnaire was used to collect the data through a face-to-face interview from January 23 to February 23, 2020. Data were entered into Epidata 3.1 and exported to SPSS version 21 for analysis. Bivariate and multivariate logistic regressions were used for analysis. A p-value of less than 0.05 was considered significant in a multivariate logistic regression analysis.

RESULTS

In total, 274 patients (83.3%) had good adherence to ART, while 16.7% did not adhere. Age between 39 and 49 years old (AOR=0.068, 95% CI 0.008, 0.578), urban residency (AOR=5.186, 95% CI 1.732, 15.529), an educational status of being unable to read and write (AOR=0.097, 95% CI 0.012, 0.771), an educational status of reading and writing with no formal education (AOR=0.056, 95% CI 0.006, 0.532), comorbidity (AOR=0.042, 95% CI 0.013, 0.139), disclosure (AOR=3.583, 95% CI 1.008, 12.739), WHO clinical stage II (AOR=0.098, 95% CI 0.021, 0.453), and CD4 count ≥500 cells/mm³ (AOR=5.634, 95% CI 1.203, 26.383) were significantly associated with adherence to ART among patients.

CONCLUSION

The adherence of patients to ART is relatively low compared to other studies conducted in different regions. Age 39-49 years, educational status, comorbidity, and WHO clinical staging were negatively associated with ART adherence. Residency, disclosure, and current CD4 category greater than or equal to 500 cells/mm³ were positively associated with adherence. Good counseling to patients from rural areas, with low educational status, and with low CD4 counts, and on the importance of disclosure, is recommended and should be given by professionals.

Transitions: Novel Study Methods to Understand Early HIV Risk Among Adolescent Girls and Young Women in Mombasa, Kenya, and Dnipro, Ukraine

Transitions aims to understand the human immunodeficiency virus (HIV) risk at critical transition points in the sexual life course of adolescent girls and young women (AGYW) who engage in casual sex, transactional sex, and sex work. In this article, we present the Transitions study methods. The Transitions study has the following objectives: (1) to describe how the characteristics and length of the transition period and access gap vary across two epidemiological contexts (Mombasa, Kenya, and Dnipro, Ukraine); (2) to understand how the risk of HIV varies by length and characteristics of the transition period and access gap across epidemiologic contexts; and (3) to assess the extent to which HIV infections acquired during the transition period and access gap could mitigate the population-level impact of focused interventions for female sex workers and explore the potential marginal benefit of expanding programs to reach AGYW during the transition period and access gap. Cross-sectional biobehavioral data were collected from young women aged 14 to 24 years who were recruited from locations in Mombasa County, Kenya, and Dnipro, Ukraine, where sex work took place. Data are available for 1,299 Kenyan and 1,818 Ukrainian participants. The survey addressed the following areas: timing of transition events (first sex, first exchange of sex for money or other resources, self-identification as sex workers, entry into formal sex work, access to prevention program services); sexual behaviors (condom use, anal sex, sex under the influence of drugs or alcohol); partnerships (regular and first-time clients, regular and first-time transactional sex partners, and husbands and boyfriends); alcohol use; injection and non-injection illicit drug use; experience of violence; access to HIV prevention and treatment program; testing for sexually transmitted and blood-borne infections and HIV; and reproductive health (pregnancies, abortions, contraceptives). HIV and hepatitis C virus prevalence data were based on rapid test results. Mathematical modeling will be used to generate projections of onward HIV transmission at specific transition points in the sexual life course of AGYW. Taken together, these data form a novel data resource providing comprehensive behavioral, structural, and biological data on a high-risk group of AGYW in two distinct sociocultural and epidemiologic contexts.

Association between HIV stigma and antiretroviral therapy adherence among adults living with HIV: baseline findings from the HPTN 071 (PopART) trial in Zambia and South Africa

OBJECTIVES

Adherence to antiretroviral therapy (ART) leads to viral suppression for people living with HIV (PLHIV) and is critical for both individual health and reducing onward HIV transmission. HIV stigma is a risk factor that can undermine adherence. We explored the association between HIV stigma and self-reported ART adherence among PLHIV in 21 communities in the HPTN 071 (PopART) trial in Zambia and the Western Cape of South Africa.

METHODS

We conducted a cross-sectional analysis of baseline data collected between 2013 and 2015, before the roll-out of trial interventions. Questionnaires were conducted, and consenting participants provided a blood sample for HIV testing. Poor adherence was defined as self-report of not currently taking ART, missing pills over the previous 7 days or stopping treatment in the previous 12 months. Stigma was categorised into three domains: community, health setting and internalised stigma. Multivariable logistic regression was used for analysis.

RESULTS

Among 2020 PLHIV self-reporting ever taking ART, 1888 (93%) were included in multivariable analysis. Poor ART adherence was reported by 15.8% (n = 320) of participants, and 25.7% (n = 519) reported experiencing community stigma, 21.5% (n = 434) internalised stigma, and 5.7% (n = 152) health setting stigma. PLHIV who self-reported previous experiences of community and internalised stigma more commonly reported poor ART adherence than those who did not (aOR 1.63, 95% CI 1.21 -2.19, P = 0.001 and aOR 1.31, 95% CI 0.96-1.79, P = 0.09).

CONCLUSIONS

HIV stigma was associated with poor ART adherence. Roll-out of universal treatment will see an increasingly high proportion of PLHIV initiated on ART. Addressing HIV stigma could make an important contribution to supporting lifelong ART adherence.

Antiretroviral therapy and the risk of sexual transmission of HIV: a systematic review and meta-analysis

OBJECTIVES

The aim of this study was to evaluate the effect of antiretroviral therapy (ART) with or without condom use on the risk of sexual transmission of HIV.

METHODS

A search of the literature was conducted in the PubMed, Web of Science, Cochrane, SCOPUS and EMBASE databases for studies dating back to 2008. The results were summarized as relative risks and incidence rates with 95% confidence intervals (CIs). The effect sizes were pooled using random-effects models and heterogeneity was evaluated using the Cochrane Q test and I² .

RESULTS

Of the 1424 studies retrieved in the initial search, 10 met the eligibility requirements. ART was associated with a 52% reduction in transmission risk compared to no ART, with a relative risk of 0.48 (95% CI 0.439-0.525) (Q = 0.524; I² = 0.0%; overall effect Z = 15.99, P < 0.0001). ART vs. no ART caused a reduction in the risk from 5.6 person-years (95% CI 3.26-9.62 person-years) (Q = 0.771; I² = 0.0%; overall effect Z = 6.25, P < 0.0001) in the untreated group to 0.85 person-years (95% CI 0.28-2.99 person-years) (Q = 0.038; I² = 76.7%; overall effect Z = 0.11, P = 0.772) in the treated group, but not significantly so, which is equivalent to an 84% reduction in the risk of sexual transmission. In accordance with the Swiss National AIDS Commission declaration, ART with suppressed viral loads was associated with a minimal risk of transmission, with a median time at risk of 0.00 person-years (95% CI 0.00-0.00 person-years) (Q = 1.00; I² = 0.0%; overall effect Z = 6.80, P < 0.0001).

CONCLUSIONS

ART and condom use were found to cause a significant reduction in the risk of sexual transmission of HIV in both homosexual and heterosexual populations, based on previous systematic reviews and meta-analyses.

Virological and immunological impact of integrase inhibitor-based regimens initiated during primary HIV-1 infection

DESIGN

Current international guidelines recommend either boosted protease inhibitor (PI/r)-based or integrase inhibitors (INSTI)-based regimens during primary HIV infection (PHI), even though the latter have only demonstrated their superiority at the chronic stage. We compared the effectiveness of INSTI-based versus PI/r-based combined antiretroviral therapy (cART) initiated during PHI.

METHODS

This study was conducted among patients who initiated cART between 2013 and 2017, using data from the ANRS-PRIMO cohort and the Dat'AIDS study. Cumulative proportions of patients reaching viral suppression (HIV-1 RNA <50 copies/ml) were calculated using Turnbull's estimator for interval-censored data. CD4 cells and CD4/CD8 ratio increases were estimated using mixed linear models. Results were adjusted for the data source.

RESULTS

Among the 712 study patients, 299 received an INSTI-based cART. Patients' baseline characteristics were similar between groups. Viral suppression was reached more rapidly in INSTI-treated versus PI/r-treated patients (P < 0.01), with cumulative proportions of 32 versus 6% at 4 weeks, 72 versus 31% at 12 weeks, 91 versus 78% at 24 weeks and about 95% in both groups at 48 weeks. At 4 weeks, INSTI-treated patients had gained on average 40 CD4 cells/μl (P = 0.05) over PI/r-treated ones; mean CD4 counts were similar in the two groups at 48 weeks. The CD4/CD8 ratio followed the same pattern. Results were similar when restricted to a comparison between dolutegravir-based versus darunavir-based cART.

CONCLUSION

On the basis of this study and available literature, we recommend the use of INSTI-based cART for treatment initiation during PHI, as it leads to faster viral suppression and immune restoration.

The impact of localized implementation: determining the cost-effectiveness of HIV prevention and care interventions across six United States cities

OBJECTIVE

Effective interventions to reduce the public health burden of HIV/AIDS can vary in their ability to deliver value at different levels of scale and in different epidemiological contexts. Our objective was to determine the cost-effectiveness of HIV treatment and prevention interventions implemented at previously documented scales of delivery in six US cities with diverse HIV microepidemics.

DESIGN

Dynamic HIV transmission model-based cost-effectiveness analysis.

METHODS

We identified and estimated previously documented scale of delivery and costs for 16 evidence-based interventions from the US CDC's Compendium of Evidence-Based Interventions and Best Practices for HIV Prevention. Using a model calibrated for Atlanta, Baltimore, Los Angeles, Miami, New York City and Seattle, we estimated averted HIV infections, quality-adjusted life years (QALY) gained and incremental cost-effectiveness ratios (healthcare perspective; 3% discount rate, 2018$US), for each intervention and city (10-year implementation) compared with the status quo over a 20-year time horizon.

RESULTS

Increased HIV testing was cost-saving or cost-effective across cities. Targeted preexposure prophylaxis for high-risk MSM was cost-saving in Miami and cost-effective in Atlanta ($6123/QALY), Baltimore ($18 333/QALY) and Los Angeles ($86 117/QALY). Interventions designed to improve antiretroviral therapy initiation provided greater value than other treatment engagement interventions. No single intervention was projected to reduce HIV incidence by more than 10.1% in any city.

CONCLUSION

Combination implementation strategies should be tailored to local epidemiological contexts to provide the most value. Complementary strategies addressing factors hindering access to HIV care will be necessary to meet targets for HIV elimination in the United States.

Development and Calibration of a Dynamic HIV Transmission Model for 6 US Cities

Background. Heterogeneity in HIV microepidemics across US cities necessitates locally oriented, combination implementation strategies to prioritize resources. We calibrated and validated a dynamic, compartmental HIV transmission model to establish a status quo treatment scenario, holding constant current levels of care for 6 US cities. Methods. Built off a comprehensive evidence synthesis, we adapted and extended a previously published model to replicate the transmission, progression, and clinical care for each microepidemic. We identified a common set of 17 calibration targets between 2012 and 2015 and used the Morris method to select the most influential parameters for calibration. We then applied the Nelder-Mead algorithm to iteratively calibrate the model to generate 2000 best-fitting parameter sets. Finally, model projections were internally validated with a series of robustness checks and externally validated against published estimates of HIV incidence, while the face validity of 25-year projections was assessed by a Scientific Advisory Committee (SAC). Results. We documented our process for model development, calibration, and validation to maximize its transparency and reproducibility. The projected outcomes demonstrated a good fit to calibration targets, with a mean goodness-of-fit ranging from 0.0174 (New York City [NYC]) to 0.0861 (Atlanta). Most of the incidence predictions were within the uncertainty range for 5 of the 6 cities (ranging from 21% [Miami] to 100% [NYC]), demonstrating good external validity. The face validity of the long-term projections was confirmed by our SAC, showing that the incidence would decrease or remain stable in Atlanta, Los Angeles, NYC, and Seattle while increasing in Baltimore and Miami. Discussion. This exercise provides a basis for assessing the incremental value of further investments in HIV combination implementation strategies tailored to urban HIV microepidemics.

Risk of sexual transmission of human immunodeficiency virus with antiretroviral therapy, suppressed viral load and condom use: a systematic review

BACKGROUND

The Public Health Agency of Canada reviewed sexual transmission of HIV between serodiscordant partners to support examination of the criminal justice system response to HIV nondisclosure by the Department of Justice of Canada. We sought to determine HIV transmission risk when an HIV-positive partner takes antiretroviral therapy, has a suppressed viral load or uses condoms.

METHODS

We conducted an overview and systematic review update by searching MEDLINE and other databases (Jan. 1, 2007, to Mar. 13, 2017; and Nov. 1, 2012, to Apr. 27, 2017, respectively). We considered reviews and studies about absolute risk of sexual transmission of HIV between serodiscordant partners to be eligible for inclusion. We used A Measurement Tool to Assess Systematic Reviews (AMSTAR) for review quality, Quality in Prognosis Studies (QUIPS) instrument for study risk of bias and then the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to assess the quality of evidence across studies. We calculated HIV incidence per 100 person-years with 95% confidence intervals (CIs). We assigned risk categories according to potential for and evidence of HIV transmission.

RESULTS

We identified 12 reviews. We selected 1 review to estimate risk of HIV transmission for condom use without antiretroviral therapy (1.14 transmissions/100 person-years, 95% CI 0.56-2.04; low risk). We identified 11 studies with 23 transmissions over 10 511 person-years with antiretroviral therapy (0.22 transmissions/ 100 person-years, 95% CI 0.14-0.33; low risk). We found no transmissions with antiretroviral therapy and a viral load of less than 200 copies/mL across consecutive measurements 4 to 6 months apart (0.00 transmissions/100 person-years, 95% CI 0.00-0.28; negligible risk regardless of condom use).

INTERPRETATION

Based on high-quality evidence, there is a negligible risk of sexual transmission of HIV when an HIV-positive sex partner adheres to antiretroviral therapy and maintains a suppressed viral load of less than 200 copies/mL measured every 4 to 6 months. Sexual transmissions of HIV have occurred when viral load was more than 200 copies/mL with antiretroviral therapy or condoms alone were used, although the risk remains low. These findings will help to support patient and clinician decision-making, affect public health case management and contact tracing, and inform justice system responses to HIV nondisclosure.

Natural Conception is Safe for HIV-Serodiscordant Couples with Persistent Suppressive Antiretroviral Therapy for the Infected Partner

Background: Sustained use of antiretroviral treatment to achieve a suppressed viral load in persons living with HIV is associated with zero or near-zero risk of sexual and vertical HIV transmission. This has led to an increasing number of HIV-serodiscordant couples (SDCs) who wish to have children. The aim of this study was to describe the most recent results of a protocol for reproductive counseling directed at HIV-SDCs who desire natural conception and to identify some of the factors influencing reproductive success. Methods: Two hundred fourteen couples were enrolled. Sociodemographic/behavioral and clinical data were collected. CD4+ lymphocyte count, HIV viral load, serology/viral load of hepatitis B/C viruses, syphilis serology, and other sexually transmitted infection diagnosis in both members of couple; spermiogram in men, HIV proviral and viral load in semen of male HIV-infected partners, and urine luteinizing hormone qualitative test in women were performed. Unprotected vaginal intercourses, pregnancies achieved, and their outcomes were recorded. Results: After almost 10,000 sexual relations, a total of 188 pregnancies was achieved, 62% of couples became pregnant once or several times with no HIV transmission to either the partner or the offspring. Younger age of woman, no fertility disorders in both members of couple, and no treatment with efavirenz in men were factors related with reproductive success. Conclusions: Natural conception, under controlled conditions, can be offered to SDCs who wish to have children as a safe method of conception and its effectiveness seems to be related to factors not different from those of the general population.

Developing a dynamic HIV transmission model for 6 U.S. cities: An evidence synthesis

BACKGROUND

Dynamic HIV transmission models can provide evidence-based guidance on optimal combination implementation strategies to treat and prevent HIV/AIDS. However, these models can be extremely data intensive, and the availability of good-quality data characterizing regional microepidemics varies substantially within and across countries. We aim to provide a comprehensive and transparent description of an evidence synthesis process and reporting framework employed to populate and calibrate a dynamic, compartmental HIV transmission model for six US cities.

METHODS

We executed a mixed-method evidence synthesis strategy to populate model parameters in six categories: (i) initial HIV-negative and HIV-infected populations; (ii) parameters used to calculate the probability of HIV transmission; (iii) screening, diagnosis, treatment and HIV disease progression; (iv) HIV prevention programs; (v) the costs of medical care; and (vi) health utility weights for each stage of HIV disease progression. We identified parameters that required city-specific data and stratification by gender, risk group and race/ethnicity a priori and sought out databases for primary analysis to augment our evidence synthesis. We ranked the quality of each parameter using context- and domain-specific criteria and verified sources and assumptions with our scientific advisory committee.

FINDINGS

To inform the 1,667 parameters needed to populate our model, we synthesized evidence from 59 peer-reviewed publications and 24 public health and surveillance reports and executed primary analyses using 11 data sets. Of these 1,667 parameters, 1,517 (91%) were city-specific and 150 (9%) were common for all cities. Notably, 1,074 (64%), 201 (12%) and 312 (19%) parameters corresponded to categories (i), (ii) and (iii), respectively. Parameters ranked as best- to moderate-quality evidence comprised 39% of the common parameters and ranged from 56%-60% across cities for the city-specific parameters. We identified variation in parameter values across cities as well as within cities across risk and race/ethnic groups.

CONCLUSIONS

Better integration of modelling in decision making can be achieved by systematically reporting on the evidence synthesis process that is used to populate models, and by explicitly assessing the quality of data entered into the model. The effective communication of this process can help prioritize data collection of the most informative components of local HIV prevention and care services in order to reduce decision uncertainty and strengthen model conclusions.

Genetic Cluster Analysis for HIV Prevention

PURPOSE OF REVIEW

This review summarizes the use of genetic similarity clusters to understand HIV transmission and inform prevention efforts.

RECENT FINDINGS

Recent emphases include the development of real-time cluster identification in order to interrupt transmission chains, the use of clusters to estimate rates of transmission along the HIV care cascade, and the extension of cluster analyses to understand transmission in the generalized epidemics of sub-Saharan Africa. Importantly, this recent empirical work has been accompanied by theoretical work that elucidates the processes that underlie HIV genetic similarity clusters; multiple studies suggest that clusters are not necessarily enriched with individuals with high transmission rates, but rather can reflect variation in sampling times within a population, with individuals sampled early in infection more likely to cluster. Analyses of genetic similarity clusters have great promise to inform HIV epidemiology and prevention. Future emphases should include the collection of additional sequence data from underrepresented populations, such as those in sub-Saharan Africa, and further development and evaluation of clustering methods.

Effects of antiretroviral therapy in HIV-positive adults on new HIV infections among young women: a systematic review protocol

BACKGROUND

The HIV/AIDS pandemic has struck regions, countries, and populations in different ways. With the introduction of antiretroviral drugs, people living with HIV (PLHIV) have a much better prognosis, even though there are still many new infections in young women. The role of widespread antiretroviral therapy (ART) on the incidence of HIV in young women is unknown.

METHODS

We will conduct a comprehensive search of MEDLINE (PubMed), Excerpta Medica database (EMBASE), Scopus, Google Scholar, Cochrane Central Register of Controlled Trials (CENTRAL), World Health Organization's (WHO's) library database, Latin American and Caribbean Health Sciences Literature (LILACS), conference abstracts, and gray literature sources to identify any relevant literature. We will include randomized and non-randomized clinical trials and cohort studies in which ART was offered to adults aged 18 and above reporting outcomes in females aged 15 to 24 years. The outcomes of interest are HIV incidence, ART initiation, adherence, retention, and viral load suppression. We will screen titles, abstracts, and the full texts of relevant articles in duplicate. Disagreements will be resolved by consensus. We will extract data on the risk of HIV infection in younger females after the use of ART in the adult population.

DISCUSSION

To our knowledge, this is the first systematic review to look at the impact of ART use among adults on HIV incidence in young women. The results of this review will be used in a modeling study to simulate the effects of using ART as an effective tool to prevent sexual transmission of HIV to young women. Our findings will inform the treatment-as-prevention (TasP) strategy to reduce new HIV infections among young women.

SYSTEMATIC REVIEW REGISTRATION

The systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO), registration number CRD42018099174 .

Appraising the value of evidence generation activities: an HIV modelling study

Introduction

The generation of robust evidence has been emphasised as a priority for global health. Evidence generation spans a wide range of activities including clinical trials, surveillance programmes and health system performance measurement. As resources for healthcare and research are limited, the desirability of research expenditure should be assessed on the same basis as other healthcare resources, that is, the health gains from research must be expected to exceed the health opportunity costs imposed as funds are diverted to research rather than service provision.

Methods

We developed a transmission and costing model to examine the impact of generating additional evidence to reduce uncertainties on the evolution of a generalised HIV epidemic in Zambia.

Results

We demonstrate three important points. First, we can quantify the value of additional evidence in terms of the health gain it is expected to generate. Second, we can quantify the health opportunity cost imposed by research expenditure. Third, the value of evidence generation depends on the budgetary policies in place for managing HIV resources under uncertainty. Generating evidence to reduce uncertainty is particularly valuable when decision makers are required to strictly adhere to expenditure plans and when transfers of funds across geographies/programmes are restricted.

Conclusion

Better evidence can lead to health improvements in the same way as direct delivery of healthcare. Quantitative appraisals of evidence generation activities are important and should reflect the impact of improved evidence on population health, evidence generation costs and budgetary policies in place.

Does per-act HIV-1 transmission risk through anal sex vary by gender? An updated systematic review and meta-analysis

Quantifying HIV-1 transmission risk per-act of anal intercourse (AI) is important for HIV-1 prevention. We updated previous reviews by searching Medline and Embase to 02/2018. We derived pooled estimates of receptive AI (URAI) and insertive AI (UIAI) risk unprotected by condoms using random-effects models. Subgroup analyses were conducted by gender, study design, and whether antiretroviral treatment (ART) had been introduced by the time of the study. Two new relevant studies were identified, one of which met inclusion criteria, adding three new cohorts and increasing number of individuals/partnerships included from 1869 to 14 277. Four studies, all from high-income countries, were included. Pooled HIV-1 risk was higher for URAI (1.25%, 95% CI 0.55%-2.23%, N = 5, I²  = 87%) than UIAI (0.17%, 95 % CI 0.09%-0.26%, N = 3, I²  = 0%). The sole heterosexual URAI estimate (3.38%, 95% CI 1.85%-4.91%), from a study of 72 women published in a peer-reviewed journal, was significantly higher than the men-who-have-sex-with-men (MSM) pooled estimate (0.75%, 95% CI 0.56%-0.98%, N = 4, P < 0.0001) and higher than the only other heterosexual estimate identified (0.4%, 95% CI 0.08%-2.0%, based on 59 women, excluded for being a pre-2013 abstract). Pooled per-act URAI risk varied by study design (retrospective-partner studies: 2.56%, 95% CI 1.20%-4.42%, N = 2 (one MSM, one heterosexual); prospective studies: 0.71%, 95% CI 0.51%-0.93%, N = 3 MSM, P < 0.0001). URAI risk was lower for studies conducted in the ART era (0.75%, 95% CI 0.52%-1.03%) than pre-ART (1.67%, 95% CI 0.44%-3.67%) but not significantly so (P = 0.537). Prevention messages must emphasize that HIV-1 infectiousness through AI remains high, even in the ART era. Further studies, particularly among heterosexual populations and in resource-limited settings, are required to elucidate whether AI risk differs by gender, region and following population-level ART scale-up.

Success factors for universal access to antiretroviral treatments in South Africa

This article studies the epidemiological and economic impacts of a universal testing and treatment policy of Human Immunodeficiency Virus (HIV) in South Africa. A model of disease transmission is built to simulate several implementation scenarios of the policy. Different behavioral responses in the general population are considered. The results show that the success of a large-scale HIV testing and treatment program in South Africa depends on its implementation conditions. The policy can lead to a reduction of the HIV epidemic, even in the case of a large relapse in preventive behaviors in the general population, if implementation conditions are favorable. This is the case if the number of infected individuals who are infectious is greatly reduced. From an economic point of view, taking into account the positive externality of antiretroviral (ARV) treatments changes the traditional framework of cost-benefit analyses. A large-scale testing and treatment program would be cost-saving in the case of favorable implementation conditions, even following a large increase in risk behaviors after the scaling up of ARV treatments. By contrast, the analysis stresses out the potential perverse effects of scaling up ARV treatments in South Africa if the intervention is set up without ensuring enough resources for patients' monitoring and the availability of effective ARV drugs. Indeed, if the number of treated patients rises while adherence of patients to treatments decreases and the rate of loss to follow-up increases, the policy could extend the pool of infectious patients and lead to a long-term amplification of the epidemic.

Couple serostatus patterns in sub-Saharan Africa illuminate the relative roles of transmission rates and sexual network characteristics in HIV epidemiology

HIV prevalence has surpassed 30% in some African countries while peaking at less than 1% in others. The extent to which this variation is driven by biological factors influencing the HIV transmission rate or by variation in sexual network characteristics remains widely debated. Here, we leverage couple serostatus patterns to address this question. HIV prevalence is strongly correlated with couple serostatus patterns across the continent; in particular, high prevalence countries tend to have a lower ratio of serodiscordancy to concordant positivity. To investigate the drivers of this continental pattern, we fit an HIV transmission model to Demographic and Health Survey data from 45,041 cohabiting couples in 25 countries. In doing so, we estimated country-specific HIV transmission rates and sexual network characteristics reflective of pre-couple and extra-couple sexual contact patterns. We found that variation in the transmission rate could parsimoniously explain between-country variation in both couple serostatus patterns and prevalence. In contrast, between-country variation in pre-couple or extra-couple sexual contact rates could not explain the observed patterns. Sensitivity analyses suggest that future work should examine the robustness of this result to between-country variation in how heterogeneous infection risk is within a country, or to assortativity, i.e. the extent to which individuals at higher risk are likely to partner with each other.

High Burden of HIV, Syphilis and HSV-2 and Factors Associated with HIV Infection Among Female Sex Workers in Tanzania: Implications for Early Treatment of HIV and Pre-exposure Prophylaxis (PrEP)

This paper estimates population-based prevalence of HIV, syphilis, HSV-2 and factors influencing HIV infection using a national sample of 1914 female sex workers (FSWs) in 7 regions in Tanzania. Additionally, HIV incidence was estimated by comparing biological HIV results with self-reported HIV status. The average HIV prevalence among FSWs in all 7 regions was 28%, ranging from 14% in Tabora to 38% in Shinyanga. HIV incidence was found to be 13 per 100 person-years. Syphilis prevalence was 8% with significantly higher burden found in Iringa (11%), Mbeya (13%), and Shinyanga (12%). Nearly 60% of the study population was infected with HSV-2. The high HIV prevalence and incidence coupled with suboptimal condom use indicate an urgent need to roll out the "Treat-All" approach and provide antiretroviral therapy to FSWs living with HIV regardless of their CD4 count. In addition, antiretroviral-based prevention technologies such as oral pre-exposure prophylaxis and microbicides should be piloted and evaluated.

Economic and public health consequences of delayed access to medical care for migrants living with HIV in France

In 2013, migrants accounted for 46% of newly diagnosed cases of HIV (human immunodeficiency virus) infection in France. These populations meet with specific obstacles leading to late diagnosis and access to medical care. Delayed access to care (ATC) for HIV-infected migrants reduces their life expectancy and quality of life. Given the reduction of infectivity under antiretroviral (ARV) treatment, delayed ATC for HIV-infected migrants may also hinder the control of the HIV epidemic. The objective of this study is to measure the public health and economic consequences of delayed ATC for migrants living with HIV in France. Using a healthcare payer perspective, our model compares the lifetime averted infections and costs of early vs. late ATC for migrants living with HIV in France. Early and late ATC are defined by an entry into care with a CD4 cell count of 350 and 100/mm³, respectively. Our results show that an early ATC is dominant, even in the worst-case scenario. In the most favorable scenario, early ATC generates an average net saving of €198,000 per patient, and prevents 0.542 secondary infection. In the worst-case scenario, early ATC generates an average net saving of €32,000 per patient, and prevents 0.299 secondary infection. These results are robust to various adverse changes in key parameters and to a definition of late ATC as an access to care at a CD4 level of 200/mm³. In addition to individual health benefits, improving ATC for migrants living with HIV proves efficient in terms of public health and economics. These results stress the benefit of ensuring early ATC for all individuals living with HIV in France.

Impact of early antiretroviral therapy eligibility on HIV acquisition: household-level evidence from rural South Africa

Objectives:

We investigate the effect of immediate antiretroviral therapy (ART) eligibility on HIV incidence among HIV-uninfected household members.

Design:

Regression discontinuity study arising from a population-based cohort.

Methods:

Household members of patients seeking care at the Hlabisa HIV Treatment and Care Programme in rural KwaZulu-Natal South Africa between January 2007 and August 2011 with CD4⁺ cell counts up to 350 cells/μl were eligible for inclusion if they had at least two HIV tests and were HIV-uninfected at the time the index patient linked to care (N = 4115). Regression discontinuity was used to assess the intention-to-treat effect of immediate versus delayed ART eligibility on HIV incidence among household members. Exploiting the CD4⁺ cell count-based threshold rule for ART initiation (CD4⁺ < 200 cells/μl until August 2011), we used Cox proportional hazards models to compare outcomes for household members of patients who presented for care with CD4⁺ cell counts just above versus just below the ART initiation threshold.

Results:

Characteristics of household members of index patients initiating HIV care were balanced between those with an index patient immediately eligible for ART (N = 2489) versus delayed for ART (N = 1626). There were 337 incident HIV infections among household members, corresponding to an HIV incidence of 2.4 infections per 100 person-years (95% confidence interval 2.5–3.1). Immediate eligibility for treatment reduced HIV incidence in households by 47% in our optimal estimate (hazard ratio = 0.53, 95% confidence interval 0.30–0.96), and by 32–60% in alternate specifications of the model.

Conclusion:

Immediate eligibility of ART led to substantial reductions in household-level HIV incidence.

Families Living with Blood-Borne Viruses: The Case for Extending the Concept of "Serodiscordance"

The concept of “serodiscordance” (mixed infection status) is primarily associated with epidemiological concerns about HIV transmission risk in couples. We make the case for extending this concept to include families with mixed HIV and viral hepatitis status. Social research on couples with mixed HIV and hepatitis C status has laid an important foundation for illuminating how experiences of serodiscordance within intimate partnerships are much broader than concerns about risk. This body of work attests to serodiscordance holding promise as a valuable concept for understanding viral infections as socially situated and intensely relational phenomena. However, serodiscordance is still limited as a concept because of its near universal focus on couples. It is rarely applied to wider relationships, including family networks beyond the couple. Despite evidence in the literature that families are affected by blood-borne viruses in multiple social, emotional, financial, and generational ways, the concept of serodiscordance does not capture these broader dynamics. Making serodiscordance more inclusive is an important step in recognising the diverse ways families' everyday lives, relationships, and futures can be entangled with HIV, hepatitis C, and hepatitis B, and for understanding how today's era of effective treatment options might shape the “family life” of viral infections.

Improving ART programme retention and viral suppression are key to maximising impact of treatment as prevention - a modelling study

Background

UNAIDS calls for fewer than 500,000 new HIV infections/year by 2020, with treatment-as-prevention being a key part of their strategy for achieving the target. A better understanding of the contribution to transmission of people at different stages of the care pathway can help focus intervention services at populations where they may have the greatest effect. We investigate this using Uganda as a case study.

Methods

An individual-based HIV/ART model was fitted using history matching. 100 model fits were generated to account for uncertainties in sexual behaviour, HIV epidemiology, and ART coverage up to 2015 in Uganda. A number of different ART scale-up intervention scenarios were simulated between 2016 and 2030. The incidence and proportion of transmission over time from people with primary infection, post-primary ART-naïve infection, and people currently or previously on ART was calculated.

Results

In all scenarios, the proportion of transmission by ART-naïve people decreases, from 70% (61%–79%) in 2015 to between 23% (15%–40%) and 47% (35%–61%) in 2030. The proportion of transmission by people on ART increases from 7.8% (3.5%–13%) to between 14% (7.0%–24%) and 38% (21%–55%). The proportion of transmission by ART dropouts increases from 22% (15%–33%) to between 31% (23%–43%) and 56% (43%–70%).

Conclusions

People who are currently or previously on ART are likely to play an increasingly large role in transmission as ART coverage increases in Uganda. Improving retention on ART, and ensuring that people on ART remain virally suppressed, will be key in reducing HIV incidence in Uganda.

Evaluation of the performance of Abbott m2000 and Roche COBAS Ampliprep/COBAS Taqman assays for HIV-1 viral load determination using dried blood spots and dried plasma spots in Kenya

BACKGROUND

Routine HIV viral load testing is not widely accessible in most resource-limited settings, including Kenya. To increase access to viral load testing, alternative sample types like dried blood spots (DBS), which overcome the logistic barriers associated with plasma separation and cold chain shipment need to be considered and evaluated. The current study evaluated matched dried blood spots (DBS) and dried plasma spots (DPS) against plasma using the Abbott M 2000 (Abbott) and Roche Cobas Ampliprep/Cobas TaqMan (CAP/CTM) quantitative viral load assays in western Kenya.

METHODS

Matched plasma DBS and DPS were obtained from 200 HIV-1 infected antiretroviral treatment (ART)-experienced patients attending patient support centers in Western Kenya. Standard quantitative assay performance parameters with accompanying 95% confidence intervals (CI) were assessed at the assays lower detection limit (400cps/ml for CAP/CTM and 550cps/ml for Abbott) using SAS version 9.2. Receiver operating curves (ROC) were further used to assess viral-load thresholds with best assay performance (reference assay CAP/CTM plasma).

RESULTS

Using the Abbott test, the sensitivity and specificity, respectively, for DPS were (97.3%, [95%CI: 93.2-99.2] and 98.1% [95%CI: 89.7-100]) and those for DBS (93.9% [95%CI: 88.8-97.2] and 88.0% [95%CI: 82.2-92.4]). The correlation and agreement using paired plasma and DPS/DBS were strong, with r2 = 90.5 and rc = 68.1. The Bland-Altman relative percent change was 95.3 for DPS, (95%CI: 90.4-97.7) and 73.6 (95%CI: 51.6-86.5) for DBS. Using the CAP/CTM assay, the sensitivity for DBS was significantly higher compared to DPS (100.0% [95% CI: 97.6-100.0] vs. 94.7% [95%CI: 89.8-97.7]), while the specificity for DBS was lower: 4%, [95% CI: 0.4-13.7] compared to DPS: 94.0%, [95% CI: 83.5-98.7]. When compared under different clinical relevant thresholds, the accuracy for the Abbott assay was 95% at the 1000cps/ml cut-off with a sensitivity and specificity of 96.6% [95% CI 91.8-98.7] and 90.4% [95% CI 78.2-96.4] respectively. The optimum threshold was at 3000 cps/ml with an accuracy of 95.5%, sensitivity and specificity of 94.6% [95%CI 89.3-97.5] and 98.1% [95%CI 88.4-99.9]) respectively. The best threshold for CAP/CTM was at 4000 copies /mL, with 92.5% accuracy (sensitivity of 96.0% [95%CI 91.0-98.3] and specificity of 82.7% [95%CI 69.2-91.3]).

CONCLUSIONS

There was similar performance between matched DBS, DPS and plasma using the Abbott test, and good correlation for matched DPS and plasma using the CAPCTM test. The findings suggest that DBS and DPS may be reliably used as alternative specimens to plasma to measure HIV-1 VL using Abbott, and DPS may be reliably used with CAP/CTM in resource-limited settings.

Optimal costs of HIV pre-exposure prophylaxis for men who have sex with men

Introduction

Men who have sex with men (MSM) are disproportionately affected by HIV due to their increased risk of infection. Oral pre-exposure prophylaxis (PrEP) is a highly effictive HIV-prevention strategy for MSM. Despite evidence of its effectiveness, PrEP uptake in the United States has been slow, in part due to its cost. As jurisdictions and health organizations begin to think about PrEP scale-up, the high cost to society needs to be understood.

Methods

We modified a previously-described decision-analysis model to estimate the cost per quality-adjusted life-year (QALY) gained, over a 1-year duration of PrEP intervention and lifetime time horizon. Using updated parameter estimates, we calculated: 1) the cost per QALY gained, stratified over 4 strata of PrEP cost (a function of both drug cost and provider costs); and 2) PrEP drug cost per year required to fall at or under 4 cost per QALY gained thresholds.

Results

When PrEP drug costs were reduced by 60% (with no sexual disinhibition) to 80% (assuming 25% sexual disinhibition), PrEP was cost-effective (at <$100,000 per QALY averted) in all scenarios of base-case or better adherence, as long as the background HIV prevalence was greater than 10%. For PrEP to be cost saving at base-case adherence/efficacy levels and at a background prevalence of 20%, drug cost would need to be reduced to $8,021 per year with no disinhibition, and to $2,548 with disinhibition.

Conclusion

Results from our analysis suggest that PrEP drug costs need to be reduced in order to be cost-effective across a range of background HIV prevalence. Moreover, our results provide guidance on the pricing of generic emtricitabine/tenofovir disoproxil fumarate, in order to provide those at high risk for HIV an affordable prevention option without financial burden on individuals or jurisdictions scaling-up coverage.

Modelling the evolution of HIV-1 virulence in response to imperfect therapy and prophylaxis

Average HIV-1 virulence appears to have evolved in different directions in different host populations since antiretroviral therapy first became available, and models predict that HIV drugs can select for either higher or lower virulence, depending on how treatment is administered. However, HIV virulence evolution in response to "leaky" therapy (treatment that imperfectly suppresses viral replication) and the use of preventive drugs (pre-exposure prophylaxis) has not been explored. Using adaptive dynamics, we show that higher virulence can evolve when antiretroviral therapy is imperfectly effective and that this evolution erodes some of the long-term clinical and epidemiological benefits of HIV treatment. The introduction of pre-exposure prophylaxis greatly reduces infection prevalence, but can further amplify virulence evolution when it, too, is leaky. Increasing the uptake rate of these imperfect interventions increases selection for higher virulence and can lead to counterintuitive increases in infection prevalence in some scenarios. Although populations almost always fare better with access to interventions than without, untreated individuals could experience particularly poor clinical outcomes when virulence evolves. These findings predict that antiretroviral drugs may have underappreciated evolutionary consequences, but that maximizing drug efficacy can prevent this evolutionary response. We suggest that HIV virulence evolution should be closely monitored as access to interventions continues to improve.

"I Do Not Take My Medicine while Hiding" - A Longitudinal Qualitative Assessment of HIV Discordant Couples' Beliefs in Discordance and ART as Prevention in Uganda

BACKGROUND

HIV negative members of serostatus discordant couples are at high risk for HIV acquisition, but few interventions are in place to target them in sub-Saharan Africa.

METHODS

In this study, we interviewed 28 couples, 3 times over a period of one year to understand their perceptions and attitudes around discordance, their relationship dynamics, their HIV risk behaviour, their beliefs and attitudes about antiretroviral therapy (ART) and their views of the community perceptions of discordance and treatment for HIV.

RESULTS

Findings revealed that at baseline there were multiple complex explanations and interpretations about discordance among discordant couples and their surrounding community. Shifts in beliefs and attitudes about discordance, HIV risk reduction and ART over time were enabled through re-testing negative members of discordant couples and repeat counselling but some beliefs remain solidly embedded in cultural imperatives of the importance of childbearing as well as culturally determined and enforced gender roles.

CONCLUSIONS

Interventions that aim to target discordant couples must embrace the complex and dynamic understandings of HIV diagnosis and treatment in context of fluid relationships, and changing beliefs about HIV risk and treatment.

Beyond Risk Compensation: Clusters of Antiretroviral Treatment (ART) Users in Sexual Networks Can Modify the Impact of ART on HIV Incidence

Introduction

Concerns about risk compensation—increased risk behaviours in response to a perception of reduced HIV transmission risk—after the initiation of ART have largely been dispelled in empirical studies, but other changes in sexual networking patterns may still modify the effects of ART on HIV incidence.

Methods

We developed an exploratory mathematical model of HIV transmission that incorporates the possibility of ART clusters, i.e. subsets of the sexual network in which the density of ART patients is much higher than in the rest of the network. Such clusters may emerge as a result of ART homophily—a tendency for ART patients to preferentially form and maintain relationships with other ART patients. We assessed whether ART clusters may affect the impact of ART on HIV incidence, and how the influence of this effect-modifying variable depends on contextual variables such as HIV prevalence, HIV serosorting, coverage of HIV testing and ART, and adherence to ART.

Results

ART homophily can modify the impact of ART on HIV incidence in both directions. In concentrated epidemics and generalized epidemics with moderate HIV prevalence (≈ 10%), ART clusters can enhance the impact of ART on HIV incidence, especially when adherence to ART is poor. In hyperendemic settings (≈ 35% HIV prevalence), ART clusters can reduce the impact of ART on HIV incidence when adherence to ART is high but few people living with HIV (PLWH) have been diagnosed. In all contexts, the effects of ART clusters on HIV epidemic dynamics are distinct from those of HIV serosorting.

Conclusions

Depending on the programmatic and epidemiological context, ART clusters may enhance or reduce the impact of ART on HIV incidence, in contrast to serosorting, which always leads to a lower impact of ART on HIV incidence. ART homophily and the emergence of ART clusters should be measured empirically and incorporated into more refined models used to plan and evaluate ART programmes.

Level of viral suppression and the cascade of HIV care in a South African semi-urban setting in 2012

OBJECTIVE

In 2012, 7 years after the introduction of antiretroviral treatment (ART) in the South African township of Orange Farm, we measured the proportion of HIV-positive people who were virally suppressed, especially among high-risk groups (women 18-29 years and men 25-34 years).

DESIGN

A community-based cross-sectional representative survey was conducted among 3293 men and 3473 women.

METHODS

Study procedures included a face-to-face interview and collection of blood samples that were tested for HIV, 11 antiretroviral drugs and HIV-viral load.

RESULTS

HIV prevalence was 17.0% [95% confidence interval: 15.7-18.3%] among men and 30.1% [28.5-31.6%] among women. Overall, 59.1% [57.4-60.8%] of men and 79.5% [78.2-80.9%] of women had previously been tested for HIV. When controlling for age, circumcised men were more likely to have been tested compared with uncircumcised men (66.1 vs 53.6%; P < 0.001). Among HIV+, 21.0% [17.7-24.6%] of men and 30.5% [27.7-33.3%] of women tested positive for one or more antiretroviral drugs. Using basic calculations, we estimated that, between 2005 and 2012, ART programs prevented between 46 and 63% of AIDS-related deaths in the community. Among antiretroviral-positive, 91.9% [88.7-94.3%] had viral suppression (viral load <400 copies/ml). The proportion of viral suppression among HIV+ was 27.0% [24.3-29.9%] among women and 17.5% [14.4-20.9%] among men. These proportions were lower among the high-risk groups: 15.6% [12.1-19.7%] among women and 8.4% [5.0-13.1%] among men.

CONCLUSION

In Orange Farm, between 2005 and 2012, ART programs were suboptimal and, among those living with HIV, the proportion with viral suppression was still low, especially among the young age groups. However, our study showed that, in reality, antiretroviral drugs are highly effective in viral suppression at an individual level.

Declining HIV Prevalence in Parallel With Safer Sex Behaviors in Burkina Faso: Evidence From Surveillance and Population-Based Surveys

HIV prevalence among pregnant women ages 15–49 declined from 7.1% to 2.0% in urban areas between 1998 and 2014, and from 2.0% to 0.5% in rural areas between 2003 and 2014; similar declines were reported in the Demographic and Health Surveys. During the same time period, individuals reported safer sex behaviors, including delayed sexual debut and reduced number of sex partners among youth, as well as increased condom use at last sex with nonmarital partners among men and women ages 15–49.

Objective:

To investigate trends in HIV prevalence and changes in reported sexual behaviors between 1998 and 2014 in Burkina Faso.

Methods:

We obtained data on HIV prevalence from antenatal care (ANC) surveillance sites (N = 9) that were consistently included in surveillance between 1998 and 2014. We also analyzed data on HIV prevalence and reported sex behaviors from 3 population-based surveys from the Demographic and Health Surveys (DHS), conducted in 1998–99, 2003, and 2010. Sex behavior indicators comprised never-married youth who have never had sex; sex with more than 1 partner; sex with a nonmarital, non-cohabiting partner; condom use at last sex with a nonmarital, non-cohabiting partner; and sex before age 15. We calculated survey-specific HIV prevalence with 95% confidence intervals (CIs) and used the chi-square test or chi-square test for trend to compare HIV prevalence across survey years and to analyze trends in reported sex behaviors.

Results:

HIV prevalence among pregnant women ages 15–49 decreased by 72% in urban areas, from 7.1% in 1998 to 2.0% in 2014, and by 75% in rural areas, from 2.0% in 2003 to 0.5% in 2014. HIV declined most in younger age groups, which is a good reflection of recent incidence, with declines of 55% among 15–19-year-olds, 72% among 20–24-year-olds, 40% among 25–29-year-olds, and 7% among those ≥30 years old (considering urban and rural data combined). Data reported in the DHS corroborated these declines in HIV prevalence: between 2003 and 2010, HIV prevalence dropped significantly—by 89% among girls ages 15–19, from 0.9% (95% CI, 0.2 to 1.6) to 0.1% (95% CI, 0.0 to 0.4), and by 78% among young women ages 20–24, from 1.8% (95% CI, 1.6 to 3.0) to 0.4% (95% CI, 0.0 to 0.7). During the same time period, people reported safer sex behaviors. For example, significantly higher percentages of never-married youth reported they had never had sex, lower percentages of sexually active youth reported multiple sex partners, and lower percentages of youth reported having sex before age 15. In addition, the percentage of men ages 20–49 reporting sex with a nonmarital, non-cohabiting partner declined significantly, while condom use at last sex with such a partner increased significantly among both men and women ages 15–49.

Conclusions:

Both ANC surveillance and population-based surveys report sharp declines in HIV prevalence in Burkina Faso between 1998 and 2014, accompanied by improvements in reported risky sex behaviors.

A curative regimen would decrease HIV prevalence but not HIV incidence unless targeted to an ART-naïve population

HIV curative strategies currently under development aim to eradicate latent provirus, or prevent viral replication, progression to AIDS, and transmission. The impact of implementing curative programs on HIV epidemics has not been considered. We developed a mathematical model of heterosexual HIV transmission to evaluate the independent and synergistic impact of ART, HIV prevention interventions and cure on HIV prevalence and incidence. The basic reproduction number was calculated to study the potential for the epidemic to be eliminated. We explored scenarios with and without the assumption that patients enrolled into HIV cure programs need to be on antiretroviral treatment (ART). In our simulations, curative regimes had limited impact on HIV incidence if only ART patients were eligible for cure. Cure implementation had a significant impact on HIV incidence if ART-untreated patients were enrolled directly into cure programs. Concurrent HIV prevention programs moderately decreased the percent of ART treated or cured patients needed to achieve elimination. We project that widespread implementation of HIV cure would decrease HIV prevalence under all scenarios but would only lower rate of new infections if ART-untreated patients were targeted. Current efforts to identify untreated HIV patients will gain even further relevance upon availability of an HIV cure.

Sexual risk behaviors among HIV-patients receiving antiretroviral therapy in Southern Thailand: roles of antiretroviral adherence and serostatus disclosure

The objective of this study was to examine the extent of unprotected sex among patients already established in HIV-medical care and their associated factors. Sexually active patients who were receiving antiretroviral therapy (ART) from five public hospitals in Trang province, Southern Thailand, were interviewed. Of 279 studied patients, 37.3% had unprotected sex in the prior 3 months and 27.2% did not disclose their serostatus to sexual partners. The median duration interquartile range (IQR) of using ART was 47 (27-60) months and 26.7% were non-adherent to ART (i.e., taking less than 95% of the prescribed doses). More than one-third had the perception that ART use would protect against HIV transmission even with unprotected sex. About 36.6% reported that they were unaware of their current CD4 counts and nearly one-third did not receive any safe sex counseling at each medical follow-up. After adjustment for potential confounders, non-adherence to ART and HIV-nondisclosure were strongly associated with an increase in the risk of unprotected sex with the adjusted odds ratio (aOR) of 5.03 (95% CI 2.68-9.44) and 3.89 (95% CI 1.57-9.61), respectively. In contrast, the risk for engaging in unprotected sex was less likely among patients having a negative-serostatus partner (aOR = 0.30; 95% CI 0.12-0.75), a longer duration of the use of ART (aOR = 0.98; 95%CI 0.97-0.99) and an unawareness of their current CD4 levels (aOR = 0.54; 95% CI 0.30-0.99). To maximize the benefits from ART, there should be a bigger emphasis on the "positive prevention" program and more efforts are needed to target the population at risk for unprotected sex. Strategies to encourage adherence to ART and for disclosure of serostatus are also required.

Socioeconomic marginalization and plasma HIV-1 RNA nondetectability among individuals who use illicit drugs in a Canadian setting

OBJECTIVE

Given that people who use illicit drugs (PWUD) often engage in prohibited income generation to support their basic needs, we sought to examine the role of these activities in shaping antiretroviral therapy (ART) adherence and plasma HIV RNA-1 viral load suppression among HIV-infected PWUD.

DESIGN

Longitudinal analyses among HIV-positive, ART-exposed PWUD in the AIDS Care Cohort to evaluate Exposure to Survival Services prospective cohort study (2005-2013).

METHODS

Generalized linear mixed-effects and mediation analyses examined the relationship between prohibited income generation (e.g., sex work, drug dealing, theft, street-based income) and virologic suppression (plasma viral load ≤50 copies/ml plasma) adjusting for adherence and potential confounders.

RESULTS

Among 687 HIV-infected PWUD, 391 (56.9%) individuals reported prohibited income generation activity during the study period. In multivariate analyses, prohibited income generation remained independently and negatively associated with virologic suppression (adjusted odds ratio: 0.68, 95% confidence interval: 0.52-0.88) following adjustment for hypothesized confounders, including high-intensity drug use, ART adherence and homelessness. Although partially mediated by ART adherence, the relationship between prohibited income generation and virologic suppression was maintained in mediation analyses (Sobel statistic = -1.95, P = 0.05).

CONCLUSION

Involvement in prohibited income generation decreases the likelihood of virologic suppression directly and indirectly through its negative association with ART adherence. These findings suggest that linkages between socioeconomic marginalization, the criminalization of illicit drug use, and insufficient employment opportunities may produce barriers to access and retention in care. Programmatic and policy interventions that decrease socioeconomic vulnerability may therefore reduce HIV-related morbidity, mortality, and onward transmission.

Are couple-based interventions more effective than interventions delivered to individuals in promoting HIV protective behaviors? A meta-analysis

Despite several advantages to bringing couples together to learn how to protect themselves and new-born children from the risk of HIV infection, most interventions are designed for individuals or groups, not for dyads. This meta-analysis provides a direct test of whether couple-based interventions are more effective in promoting HIV protective behaviors than interventions delivered to individuals. We conducted systematic searches of five electronic databases and 60 journals. Eligible studies were controlled trials or prospective cohort designs; evaluated a couple-based intervention compared to an individual-level intervention; assessed at least one HIV prevention outcome (e.g., protective sex, drug use, HIV testing, medication adherence, and sexually transmitted infections [STI]); and were published between 1988 and 2014. Fifteen interventions, including 21,882 participants from China, Kenya, Rwanda, Tanzania, Trinidad, Zambia, and the USA, were evaluated. The results of random-effects models showed statistically significant intervention effects for protective sex (OR = 1.60, 95% CI = 1.21, 2.11), HIV testing (OR = 1.79, 95% CI = 1.31, 2.45), and Nevirapine uptake (OR = 1.51, 95% CI = 1.02, 2.24). The evidence demonstrates the usefulness of couple-based interventions in protecting individuals, partners, and new-born children from the risk of HIV transmission and infection.

Predictors of couple HIV counseling and testing among adult residents of Bukomero sub-county, Kiboga district, rural Uganda

Background

Studies have shown that couple HIV counseling and testing (CHCT) increased rates of sero-status disclosure and adoption of safer sexual behaviors with better linkage to treatment and care. However, current evidence suggests that new HIV infections are occurring among heterosexual couples in stable relationships where the majority of the individuals are not aware of their partner’s serostatus. This study examined the predictors of CHCT uptake among married or cohabiting couples of Bukomero sub-county Kiboga district in Uganda.

Methods

This cross-sectional correlational study was conducted among 323 individuals who were either married or cohabiting, aged 18–49 years. Participants were enrolled from randomly selected households in Bukomero sub-county. Data were collected using an interviewer-administered questionnaire on socio-demographics, self-rating on awareness of CHCT benefits, couple discussion about HIV testing and CHCT practices. Couples were compared between those who had reported to have tested as a couple and those who had not. Binary logistic regression was performed to determine the adjusted odds ratio [aOR] and 95 % confidence intervals [CI] for CHCT uptake and the other independent variables.

Results

Of the participants 288 (89.2 %) reported to have ever taken an HIV test only 99 (34.4 %) did so as a couple. The predictors of testing for HIV as a couple were discussing CHCT with the partner (adjusted odds ratio 4.95[aOR], 95 % confidence interval [CI]:1.99–12.98; p < 0.001), awareness of CHCT benefits (aOR 3.23; 95 % CI 1.78–5.87; p < 0.001) and having time to test as a couple (aOR 2.61; 95 % CI 1.22–5.61; p <0.05).

Conclusion

Uptake of HIV counseling and testing among couples was low. Discussing CHCT with partner, awareness of CHCT benefits, and availability of time to test as a couple were predictive of CHCT uptake. Thus CHCT campaigns should emphasize communication and discussion of HIV counseling and testing among partners.

Sexual behaviour of people living with HIV attending a tertiary care government hospital in Kathmandu, Nepal: a cross sectional study

Background

Clinical improvements that follow antiretroviral therapy (ART) may lead to increase or resumption of high risk activities that could unintentionally result in HIV transmission. The objective was to investigate whether treatment status is a significant predictor of sexual risk behaviour (unprotected sex).

Methods

A cross sectional study was conducted among 160 people living with HIV (PLHIV) (89 ART experienced and 71 ART naïve) attending Sukraraj Tropical and Infectious Disease Hospital in Kathmandu, Nepal. A structured questionnaire was used for data collection. Logistic regression with stepwise modeling was used to obtain adjusted odds ratios (OR) with 95 % CI.

Results

In this study, 92 % of sexually active respondents reported sex with a regular partner. ART experienced PLHIV were significantly more likely to report consistent condom use with their regular partners compared to ART naïve PLHIV (83 vs. 53 %; P = 0.006) during the past six months. In multivariate analysis, sex (OR = 4.59, 95 % CI: 1.15–18.39), treatment status (OR = 4.76, 95 % CI: 1.29–17.52) and alcohol consumption during last sex with regular partners (OR = 14.75, 95 % CI: 2.75–79.29) were significantly associated with unprotected sex.

Conclusion

ART naïve PLHIV were five times more likely to exhibit sexual risk behaviour (have unprotected sex) than ART experienced PLHIV. Thus the study provided no evidence to suggest that ART experienced PLHIV exhibit greater sexual risk behaviour compared to ART naïve PLHIV. Prevention programmes need to emphasize on counselling to PLHIV and their regular partners with focused interventions such as couple counselling and education programmes.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-015-1559-0) contains supplementary material, which is available to authorized users.

Condom effectiveness in reducing heterosexual HIV transmission: a systematic review and meta-analysis of studies on HIV serodiscordant couples

OBJECTIVE

This systematic review and meta-analysis aimed to reassess the effectiveness of condoms in reducing heterosexual transmission of HIV.

METHODS

Medline, Scopus, and the ISI Web of Science databases were searched up to June 2014. Eligible studies were synthesized using random-effects models.

RESULTS

Twenty-five studies with 10,676 HIV serodiscordant heterosexual couples were analyzed. The risk of HIV transmission was considerably lower among couples that were always using condoms compared to never-users (RR: 0.29, 95% CI: 0.20-0.43) or inconsistent users (RR:  0.23, 0.13-0.40). The protective effect was slightly higher when the male rather than the female partner was infected (RR: 0.31, 0.20-0.48; vs. RR: 0.44, 0.24-0.80), and very high in Asian settings (RR: 0.06, 0.01-0.46).

CONCLUSIONS

Though imperfect, condoms reduce HIV transmission by more than 70% when used consistently by HIV serodiscordant heterosexual couples. Social, cultural and biological differences need to be studied further to inform projection modelers and policy makers.

Use of antiretroviral therapy in households and risk of HIV acquisition in rural KwaZulu-Natal, South Africa, 2004–12: a prospective cohort study

BACKGROUND

Studies of HIV-serodiscordant couples in stable sexual relationships have provided convincing evidence that antiretroviral therapy can prevent the transmission of HIV. We aimed to quantify the preventive effect of a public-sector HIV treatment and care programme based in a community with poor knowledge and disclosure of HIV status, frequent migration, late marriage, and multiple partnerships. Specifically, we assessed whether an individual's hazard of HIV acquisition was associated with antiretroviral therapy coverage among household members of the opposite sex.

METHODS

In this prospective cohort study, we linked patients' records from a public-sector HIV treatment programme in rural KwaZulu-Natal, South Africa, with population-based HIV surveillance data collected between 2004 and 2012. We used information about coresidence to construct estimates of HIV prevalence and antiretroviral therapy coverage for each household. We then regressed the time to HIV seroconversion for 14,505 individuals, who were HIV-uninfected at baseline and individually followed up over time regarding their HIV status, on opposite-sex household antiretroviral therapy coverage, controlling for household HIV prevalence and a range of other potential confounders.

FINDINGS

2037 individual HIV seroconversions were recorded during 54,845 person-years of follow-up. For each increase of ten percentage points in opposite-sex household antiretroviral therapy coverage, the HIV acquisition hazard was reduced by 6% (95% CI 2–9), after controlling for other factors. This effect size translates into large reductions in HIV acquisition hazards when household antiretroviral therapy coverage is substantially increased. For example, an increase of 50 percentage points in household antiretroviral therapy coverage (eg, from 20% to 70%) reduced the hazard of HIV acquisition by 26% (95% CI 9–39).

INTERPRETATION

Our findings provide further evidence that antiretroviral therapy significantly reduces the risk of onward transmission of HIV in a real-world setting in sub-Saharan Africa. Awareness that antiretroviral therapy can prevent transmission to coresident sexual partners could be a powerful motivator for HIV testing and antiretroviral treatment uptake, retention, and adherence.

FUNDING

Wellcome Trust and National Institute of Child Health and Human Development (US National Institutes of Health).

Advances in HIV prevention for serodiscordant couples

Serodiscordant couples play an important role in maintaining the global HIV epidemic. This review summarizes biobehavioral and biomedical HIV prevention options for serodiscordant couples focusing on advances in 2013 and 2014, including World Health Organization guidelines and best evidence for couples counseling, couple-based interventions, and the use of antiviral agents for prevention. In the past few years, marked advances have been made in HIV prevention for serodiscordant couples and numerous ongoing studies are continuously expanding HIV prevention tools, especially in the area of pre-exposure prophylaxis. Uptake and adherence to antiviral therapy remains a key challenge. Additional research is needed to develop evidence-based interventions for couples, and especially for male-male couples. Randomized trials have demonstrated the prevention benefits of antiretroviral-based approaches among serodiscordant couples; however, residual transmission observed in recognized serodiscordant couples represents an important and resolvable challenge in HIV prevention.

Seasonal PrEP for partners of migrant miners in southern Mozambique: a highly focused PrEP intervention

Introduction

To be used most effectively, pre-exposure prophylaxis (PrEP) should be prioritized to those at high risk of acquisition and would ideally be aligned with time periods of increased exposure. Identifying such time periods is not always straightforward, however. Gaza Province in southern Mozambique is characterized by high levels of HIV transmission and circular labour migration to mines in South Africa. A strong seasonal pattern in births is observable, reflecting an increase in conception in December. Given the potential for increased HIV transmission between miners returning in December and their partners in Gaza Province, PrEP use by the latter would be a useful means of HIV prevention, especially for couples who wish to conceive.

Methods

A mathematical model was used to represent population-level adult heterosexual HIV transmission in Gaza Province. Increased HIV acquisition among partners of miners in December, coinciding with the miners’ return from South Africa, is represented. In addition to a PrEP intervention, the scale-up of treatment and recent scale-up of male circumcision that have occurred in Gaza are represented.

Results

Providing time-limited PrEP to the partners of migrant miners, as opposed to providing PrEP all year, would improve the cost per infection averted by 7.5-fold. For the cost per infection averted to be below US$3000, at least 85% of PrEP users would need to be good adherers and PrEP would need to be cheaper than US$115 per person per year. Uncertainty regarding incidence of HIV transmission among partners of miners each year in December has a strong influence on estimates of cost per infection averted.

Conclusions

Providing time-limited PrEP to partners of migrant miners in Gaza Province during periods of increased exposure would be a novel strategy for providing PrEP. This strategy would allow for a better prioritized intervention, with the potential to improve the efficiency of a PrEP intervention considerably, as well as providing important reproductive health benefits.

The effect of sexually transmitted co-infections on HIV viral load amongst individuals on antiretroviral therapy: a systematic review and meta-analysis

Background

Antiretroviral therapy (ART) markedly reduces HIV transmission, and testing and treatment programs have been advocated as a method for decreasing transmission at the population level. Little is known, however, about the extent to which sexually transmitted infections (STIs), which increase the HIV infectiousness of untreated individuals, may decrease the effectiveness of treatment as prevention.

Methods

We searched major bibliographic databases to August 12^th, 2014 and identified studies reporting differences in HIV transmission rate or in viral load between individuals on ART who either were or were not co-infected with another STI. We used hierarchical Bayesian models to estimate viral load differences between individuals with and without STI co-infections.

Results

The search strategy retrieved 1630 unique citations of which 14 studies (reporting on 4607 HIV viral load measurements from 2835 unique individuals) met the inclusion criteria. We did not find any suitable studies that estimated transmission rates directly in both groups. Our meta-analysis of HIV viral load measurements among treated individuals did not find a statistically significant effect of STI co-infection; viral loads were, on average, 0.11 log10 (95 % CI −0.62 to 0.83) higher among co-infected versus non-co-infected individuals.

Conclusions

Direct evidence about the effects of STI co-infection on transmission from individuals on ART is very limited. Available data suggests that the average effect of STI co-infection on HIV viral load in individuals on ART is less than 1 log10 difference, and thus unlikely to decrease the effectiveness of treatment as prevention. However, there is not enough data to rule out the possibility that particular STIs pose a larger threat.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-0961-5) contains supplementary material, which is available to authorized users.

Macaque models of enhanced susceptibility to HIV

There are few nonhuman primate models of enhanced HIV susceptibility. Such models can improve comprehension of HIV acquisition risk factors and provide rigorous testing platforms for preclinical prevention strategies. This paper reviews past, current, and proposed research on macaque HIV acquisition risk models and identifies areas where modeling is significantly lacking. We compare different experimental approaches and provide practical considerations for designing macaque susceptibility studies. Modifiable (mucosal and systemic coinfections, hormonal contraception, and rectal lubricants) and non-modifiable (hormonal fluctuations) risk factors are highlighted. Risk acquisition models via vaginal, rectal, and penile challenge routes are discussed. There is no consensus on the best statistical model for evaluating increased susceptibility, and additional research is required. The use of enhanced susceptibility macaque models would benefit multiple facets of the HIV research field, including basic acquisition and pathogenesis studies as well as the vaccine and other biomedical preventions pipeline.

Potential impact of existing interventions and of antiretroviral use in female sex workers on transmission of HIV in Burkina Faso: a modeling study

BACKGROUND

The impact and cost-effectiveness of antiretroviral treatment (ART) as prevention is likely to vary depending on the local context. Burkina Faso has a concentrated mature HIV epidemic where female sex workers (FSW) are thought to have driven HIV transmission.

METHODS

A dynamic HIV transmission model was developed using data from the Yerelon FSW cohort in Bobo-Dioulasso and population surveys. Compared with current ART provision [status quo (SQ)], the model estimated the proportion of HIV infections averted or incremental life-years gained per additional person-year of ART over 20 years for ART targeting different subgroups or expanding eligibility to all HIV-infected individuals compared with SQ.

RESULTS

Modeling suggests that condom use within commercial sex has averted 40% of past HIV infections. Continuing SQ averts 35%-47% of new infections over 20 years compared with no ART. Expanding ART eligibility to all HIV-infected individuals and increasing recruitment (80% per year) could avert a further 65% of new infections, whereas targeting full-time FSW or all FSWs achieved less impact but was more efficient in terms of life-years gained per 100 person-years of ART. Local HIV elimination is possible with expanded ART provision to FSWs but requires condom use within commercial sex to be maintained at high levels.

CONCLUSIONS

Increasing FSW recruitment onto ART could be a highly efficient method for reducing HIV transmission in concentrated epidemic settings but should not be undertaken at the expense of existing interventions for FSWs. Specialized clinics providing multiple interventions for FSWs should be a fundamental component of prevention in concentrated epidemics.