Risk Factors for HIV Acquisition in High Risk Women in a Generalised Epidemic Setting

HIV incidence among women engaging in sex work in sub-Saharan Africa: a systematic review and meta-analysis

BACKGROUND

Women who engage in sex work in sub-Saharan Africa have a high risk of acquiring HIV infection. HIV incidence has declined among all women in sub-Saharan Africa, but trends among women who engage in sex work are poorly characterised. We synthesised data on HIV incidence among women who engage in sex work in sub-Saharan Africa and compared these with the total female population to understand relative incidence and trends over time.

METHODS

We searched MEDLINE, Embase, Global Health, and Google Scholar from Jan 1, 1990, to Feb 28, 2024, and grey literature for studies that reported empirical estimates of HIV incidence among women who engage in sex work in any sub-Saharan Africa country. We calculated incidence rate ratios (IRRs) compared with total female population incidence estimates matched for age, district, and year, did a meta-analysis of IRRs, and used a continuous mixed-effects model to estimate changes in IRR over time.

FINDINGS

From 32 studies done between 1985 and 2020, 2194 new HIV infections were observed among women who engage in sex work over 51 490 person-years. Median HIV incidence was 4·3 per 100 person years (IQR 2·8-7·0 per 100 person-years). Incidence among women who engage in sex work was eight times higher than matched total population women (IRR 7·8 [95% CI 5·1-11·8]), with larger relative difference in western and central Africa (19·9 [9·6-41·0]) than in eastern and southern Africa (4·9 [3·4-7·1]). There was no evidence that IRRs changed over time (IRR per 5 years: 0·9 [0·7-1·2]).

INTERPRETATION

Across sub-Saharan Africa, HIV incidence among women who engage in sex work remains disproportionately high compared with the total female population. However, constant relative incidence over time indicates HIV incidence among women who engage in sex work has declined at a similar rate. Location-specific data for women who engage in sex work incidence are sparse, but improved surveillance and standardisation of incidence measurement approaches could fill these gaps. Sustained and enhanced HIV prevention for women who engage in sex work is crucial to address continuing inequalities and ensure declines in new HIV infections.

FUNDING

Bill & Melinda Gates Foundation, UK Research and Innovation, National Institutes of Health.

TRANSLATION

For the French translation of the abstract see Supplementary Materials section.

HIV incidence among women engaging in sex work in sub-Saharan Africa: a systematic review and meta-analysis

Introduction

HIV incidence among women in sub-Saharan Africa (SSA) has declined steadily, but it is unknown whether new infections among women who engage in sex work (WESW) have declined at a similar rate. We synthesised estimates of HIV incidence among WESW in SSA and compared these to the wider female population to understand levels and trends in incidence over time.

Methods

We searched Medline, Embase, Global Health, Popline, Web of Science, and Google Scholar from January 1990 to October 2022, and grey literature for estimates of HIV incidence among WESW in SSA. We included studies reporting empirical estimates in any SSA country. We calculated incidence rate ratios (IRR) compared to age-district-year matched total female population incidence estimates. We conducted a meta-analysis of IRRs and used a continuous mixed-effects model to estimate changes in IRR over time.

Results

From 32 studies between 1985 and 2020, 2,194 new HIV infections were observed in WESW over 51,000 person-years (py). Median HIV incidence was 4.3/100py (IQR 2.8-7.0/100py), declining from a median of 5.96/100py between 1985 and 1995 to a median of 3.2/100py between 2010 and 2020. Incidence among WESW was nine times higher than in matched total population women (RR 8.6, 95%CI: 5.7-12.9), and greater in Western and Central Africa (RR 22.4, 95%CI: 11.3-44.3) than in Eastern and Southern Africa (RR 5.3, 95%CI: 3.7-7.6). Annual changes in log IRRs were minimal (-0.1% 95%CI: -6.9 to +6.8%).

Conclusions

Across SSA, HIV incidence among WESW remains disproportionately high compared to the total female population but showed similar rates of decline between 1990 and 2020. Improved surveillance and standardisation of approaches to obtain empirical estimates of sex worker incidence would enable a clearer understanding of whether we are on track to meet global targets for this population and better support data-driven HIV prevention programming.

Improving HIV pre-exposure prophylaxis persistence among adolescent girls and young women: Insights from a mixed-methods evaluation of community, hybrid, and facility service delivery models in Namibia

Introduction

Despite the potential for community-based approaches to increase access to pre-exposure prophylaxis (PrEP) for adolescent girls and young women (AGYW), there is limited evidence of whether and how they improve PrEP persistence. We compared PrEP persistence among AGYW receiving services through community and hybrid models in Namibia to facility-based services. We subsequently identify potential mechanisms to explain how and why community and hybrid models achieved (or not) improved persistence to inform further service delivery innovation.

Methods

Data were collected from PrEP service delivery to AGYW over two-years in Namibia's Khomas Region. We used Kaplan-Meier analysis to estimate survival curves for PrEP persistence beyond three-months after initiation and report the cumulative probability of persistence at one- and three-months. Persistence was defined as any PrEP use within three months after initiation followed by a PrEP refill or previously prescribed supply of at least 30 days at the three-month visit. Interviews were conducted with 28 AGYW and 19 providers and analyzed using a deductive-inductive thematic approach.

Results

From October 2017 through September 2019, 372 (18.7%) AGYW received services through a facility model, 302 (15.1%) through a community model, and 1,320 (66.2%) through a hybrid model. PrEP persistence at one- and three-months was 41.2% and 34.9% in the community model and 6.2% and 4.8% in the hybrid model compared to 36.8% and 26.7% in the facility model. Within the community and hybrid models, we identified three potential mechanisms related to PrEP persistence. Individualized service delivery offered convenience and simplicity which enabled AGYW to overcome barriers to obtaining refills but did not work as well for highly mobile AGYW. Consistent interactions and shared experiences fostered social connectedness with providers and with peers, building social networks and support systems for PrEP use. PrEP and HIV-related stigma, however, was widely experienced outside of these networks. Community-to-facility referral for PrEP refill triggered apprehension towards unfamiliar PrEP services and providers in AGYW, which discouraged persistence.

Conclusion

Service delivery approaches that offer convenience and simplicity and foster social connectedness may reduce access barriers and increase social support enabling AGYW to self-manage their PrEP use and achieve improved PrEP persistence.

Bottlenecks and Solutions During Implementation of the DREAMS Program for Adolescent Girls and Young Women in Namibia

BACKGROUND

We synthesize implementation bottlenecks experienced while implementing the DREAMS (Determined, Resilient, Empowered, AIDS-free, Mentored, and Safe) program, an HIV prevention intervention for adolescent girls and young women (AGYW), in Namibia from 2017 to 2019. Bottlenecks were organized into the following 4 AGYW program components.

PROGRAM ACCESS

Enrollment was slowed by the time-intensive nature of screening and other baseline data collection requirements, delays in acquiring parental consent, and limited time for after-school activities. Solutions included obtaining advance consent and providing 1-stop service delivery and transportation assistance.

HEALTH EDUCATION

We experienced difficulty identifying safe spaces for AGYW to meet. A lack of tailored curricula also impeded activities. Governments, stakeholders, and partners can plan ahead to help DREAMS identify appropriate safe spaces. Curricula should be identified and adapted before implementation.

HEALTH SERVICES

Uneven availability of government-provided commodities (e.g., condoms, preexposure prophylaxis [PrEP], family planning products) and lack of AGYW-centered PrEP delivery approaches impacted services. Better forecasting of commodity needs and government commitment to supply chain strengthening will help ensure adequate program stock.

SOCIAL SERVICES

The availability of only centralized care following gender-based violence (GBV) and the limited number of government social workers to manage GBV cases constrained service provision. Triaging GBV cases-i.e., referring high-risk cases to government social workers and providing DREAMS-specific social services for other cases-can ensure proper caseload management.

CONCLUSION

These bottlenecks highlight practical implementation issues and higher-level considerations for AGYW-centered HIV prevention programs. The critical need for multilayered programming for HIV/GBV prevention in AGYW cannot be addressed simply with additional funds but requires multilevel collaboration and forecasting. The urgency to achieve results must be balanced with the need for adequate implementation preparedness.

Differentiating the incidence and burden of HIV by age among women who sell sex: a systematic review and meta-analysis

INTRODUCTION

Young women who sell sex (YWSS) are at heightened risk of HIV acquisition and transmission and are among the least engaged in HIV services. There is insufficient epidemiologic evidence characterizing the burden of HIV among YWSS, particularly as compared to older WSS. These data are needed to design and tailor effective HIV prevention and treatment programmes for this population.

METHODS

We conducted two parallel systematic reviews and meta-analyses to define both the immediate and long-term HIV risks for YWSS, including among women engaged in sex work, survival sex and transactional sex. In the first review, we identified and synthesized published studies of HIV incidence comparing estimates for cisgender women ≤24 years of age versus >24. In the second review, we identified and synthesized studies of HIV prevalence, comparing estimates for cisgender women who initiated selling sex <18 versus ≥18 years. In both reviews, we completed a search of four databases for articles in any language and any geographic area published from 1 January 1980 until 12 February 2021. Included articles were assessed for quality and a random effects model was used to calculate pooled effect estimates for each review.

RESULTS AND DISCUSSION

We identified 12 studies for the HIV incidence review and 18 studies for the HIV prevalence review. In a meta-analysis, HIV incidence was elevated in younger (5.3 per 100 person-years [PY]; 95% confidence interval [CI]: 3.5, 7.1) compared to older women (2.8 per 100 PY; 95% CI: 1.7, 3.9), although CIs overlapped. HIV prevalence among those who initiated selling sex <18 years of age (28.8; 95% CI: 18.9, 38.7) was higher than those who initiated later (20.5; 95% CI: 12.4, 28.6).

CONCLUSIONS

These companion reviews offer an important perspective on the relative HIV risk of engaging in selling sex at a younger age. Our findings highlight the unique and intersectional challenges YWSS face, and the importance of ensuring that health services are tailored to meet their specific needs. Research and programming should routinely stratify data into meaningful age bands to differentiate and intervene within this population.

An analysis of the relationship between HIV risk self-perception with sexual behaviour and HIV status in South African older adults

Objective: To examine how older adults perceive their own risk of acquiring HIV; and how this perception correlates with their sexual behaviour and HIV status.Methods: We used cross-sectional survey data for 435 adults aged 50 years and older from South Africa. All participants completed a questionnaire on their basic socio-demographic and economic factors, self-reported health, sexual behaviour, HIV knowledge and attitudes, and self-perceived risk of HIV acquisition. In addition, anthropometrical measurements (weight, height, blood pressure, cholesterol) and HIV testing were conducted. Multinomial logistic regressions were used to determine the association between self-perceived HIV risk (categorised as "not at risk", at "low risk", at "high risk" and "didn't know") and being sexually active and testing HIV-positive, controlling for socio-demographic, behavioural and health-related factors.Results: Of the 435 respondents, 9.4% perceived themselves as at high risk of HIV infection, 18.9% as at low risk and 53.6% believed they were not at risk of HIV. Most respondent who perceived themselves as at low risk or not-at-risk at all of HIV were not sexually active. Older adults that were sexually active were more likely to consider themselves as at high risk of acquiring HIV (relative risk ratio [RRR] 2.05; 95% confidence interval (CI) 1.05-4.00; p = 0.036), as well as to test HIV positive (RRR 10.5; 95% CI 3.8-29.1; p < 0.001). Self-perceived HIV risk was significantly associated with age, sex, population group, and a greater awareness about HIV and how it is transmitted.Conclusions: Older persons who perceived themselves as at high risk of HIV were closely associated with sexual activity and testing HIV positive. Therefore, there is an urgent need for older persons, particularly those who remain sexually active, to screen and test for HIV routinely. Furthermore, there should be policy and programme interventions, such as the development of a simple risk-assessment tool for older adults to determine their risk for HIV. Older persons have been neglected in sexual health and HIV programmes. There is, therefore, a need to encourage older persons to take up appropriate HIV risk reduction and prevention behaviours.

Pregnancy rates and outcomes in a longitudinal HIV cohort in the context of evolving antiretroviral treatment provision in South Africa

BACKGROUND

In South Africa, women continue to face a high burden of Human Immunodeficiency Virus (HIV) infection and the possible complications thereof during pregnancy. We assessed pregnancy incidence rates and outcomes in a longitudinal HIV cohort study over a 15-year period.

METHODS

We evaluated pregnancies among women ≥ 18 years between 2004 and 2019 in the CAPRISA 002 study. We analysed pregnancy rates following HIV acquisition, CD4 counts and HIV viral load dynamics and pregnancy outcomes. We used linear regression to assess if the mean CD4 and log10 viral load close to delivery increases or decreases linearly across three different timepoints.

RESULTS

In total 245 women enrolled into the HIV negative study phase, 225 into the HIV infection phase and 232 in the antiretroviral therapy (ART) phase. Median follow-up time was 2.0 years [Interquartile Range (IQR) 0.8-2.0] during the HIV negative phase, 2.6 years; (IQR) 1.2-4.8] during HIV infection and 3.7 years (IQR 1.8-5.0) on ART, with maximum follow-up time of 2, 10 and 6 years respectively. Overall, 169 pregnancies occurred in 140 women, of which 16 pregnancies were observed during acute or early HIV infection [Incidence Rate (IR) 8.0 per 100 women-years; 95% confidence interval (CI): 4.6-12.9], 48 during established infection [IR 9.3; (CI 6.8-12.3)] and 68 on ART [IR 8.9; (CI: 7.0 - 11.4)]. Birth outcomes from 155/169 (91.7%) pregnancies were 118 (76.1%) full term live births, 17 (10.9%) premature live births, 9 (5.8%) therapeutic/elective miscarriages, 8 (5.1%) spontaneous miscarriages and 3 (1.9%) spontaneous foetal deaths or stillbirths. Six mother-to-child transmission events occurred, with four documented prior to 2008. Over time, mean CD4 count in pregnant women increased from 395 cells/µL (2004-2009) to 543 cells/µL (2010-2014) and to 696 cells/µL (2015-2019), p < 0.001. Conversely, the viral load declined from 4.2 log10 copies/ml to 2.5 log10 copies/ml and to 1.2 log10 copies/ml (p < 0.001) for the corresponding periods.

CONCLUSIONS

Pregnancy rates following HIV acquisition were high, emphasising a need for timeous ART provision and contraception counselling in women recently diagnosed with HIV. CD4 count and HIV viral load trajectories reflect improvements in treatment guidance for pregnant women over time.

Development and Evaluation of Nanoparticles-in-Film Technology to Achieve Extended In Vivo Exposure of MK-2048 for HIV Prevention

MK-2048 is a second-generation integrase inhibitor active against HIV, which has been applied vaginally using ring formulations. In this work, a nanoparticle-in-film technology was developed as a discrete pre-exposure prophylactic product option against HIV for an extended duration of use. A film platform loaded with poly (lactic-co-glycolic acid) nanoparticles (PNP) encapsulating MK-2048 was engineered. MK-2048 PNPs were loaded into films that were manufactured via the solvent casting method. Physicochemical and mechanical properties, in vitro efficacy, Lactobacillus compatibility, in vitro and ex vivo permeability, and in vivo pharmacokinetics in macaques were evaluated. PNPs with a mean diameter of 382.2 nm and −15.2 mV zeta potential were obtained with 95.2% drug encapsulation efficiency. PNP films showed comparable in vitro efficacy to free MK-2048 (IC50 0.46 vs. 0.54 nM) and were found to have no impact on Lactobacillus. MK-2048 encapsulated in PNPs showed an increase in permeability (>4-fold) compared to the free MK-2048 in MDCKII cell lines. Furthermore, PNPs had higher ectocervical tissue permeability (1.7-fold) compared to free MK-2048. PNP films showed sustained drug levels for at least 3 weeks in the macaque vaginal fluid. This work demonstrates the synergy of integrating nanomedicine and polymeric film technology to achieve sustained vaginal drug delivery.

Comparison of Female Genital Tract Cytokine and Microbiota Signatures Induced by Initiation of Intramuscular DMPA and NET-EN Hormonal Contraceptives - a Prospective Cohort Analysis

Background

Cervicovaginal inflammation, bacterial microbiota and hormonal contraceptives all influence sexual and reproductive health. To date, the effects of intramuscular depo-medroxyprogesterone acetate (DMPA-IM) versus injectable norethisterone enanthate (NET-EN) on vaginal microbiota or cytokines have not been compared back-to-back, although in-vitro data suggest that DMPA-IM and NET-EN have different pharmacokinetic and biologic activities. This study aimed at comparing the effects of DMPA-IM versus NET-EN initiation on cervicovaginal cytokines and microbiota in women at high risk for sexually transmitted infections (STIs) assigned to the respective contraceptives.

Methods

We collected socio-demographic characteristics and vaginal samples from women initiating DMPA-IM (ECHO Trial; n = 53) and NET-EN (UChoose Trial; n = 44) at baseline and after two consecutive injections to assess cytokine concentrations by Luminex, vaginal microbiota by 16S rRNA gene sequencing, STIs, bacterial vaginosis (BV) and candidiasis.

Results

Cytokine concentrations did not change significantly after initiating DMPA-IM or NET-EN, although NET-EN versus DMPA-IM-associated profiles were distinct. While the abundance of bacterial taxa associated with optimal and non-optimal microbiota fluctuated with DMPA-IM use, overall community composition did not significantly change with either contraceptive. HSV-2 serology, chlamydial infection, gonorrhoea and candidiasis did not influence the associations between contraceptive type and cervicovaginal cytokines or microbiota.

Conclusions

Both DMPA-IM and NET-EN use did not lead to broad inflammatory or microbiota changes in the female genital tract of sub-Saharan African women. This suggests that NET-EN is likely a viable option for contraception in African women at high risk of BV and STIs.

HIV Prevention Program Eligibility Among Adolescent Girls and Young Women - Namibia, 2019

The U.S. President's Emergency Plan for AIDS Relief (PEPFAR) relies on comprehensive and reliable population data to implement interventions to reduce HIV transmission in high-incidence areas among populations disproportionately affected by the HIV epidemic. Adolescent girls and young women in sub-Saharan Africa account for a disproportionate number of new HIV infections compared with their male peers (1). The DREAMS (Determined, Resilient, Empowered, AIDS-free, Mentored, and Safe) program includes multisectoral, layered interventions aimed at reducing factors that contribute to vulnerability to HIV infection among adolescent girls and young women in PEPFAR-supported sub-Saharan African countries (1). Namibia, a southern African country with a population of approximately 2.55 million among whom approximately 8% live with HIV infection, had their DREAMS program first implemented in 2017* (2,3). Data from the 2019 Namibia Violence Against Children and Youth Survey (VACS), the most recent and comprehensive nationally representative data source available to study the epidemiology of violence and other HIV risk factors, were used to estimate the percentage of adolescent girls and young women aged 13-24 years who would be eligible for DREAMS program services. The prevalence of individual DREAMS eligibility criteria, which comprise known age-specific risk factors associated with HIV acquisition, were estimated by age group. Among all adolescent girls and young women in Namibia, 62% were eligible for DREAMS based on meeting at least one criterion. Common eligibility criteria included adverse childhood experiences, specifically exposure to physical, emotional, and sexual violence and being an orphan;^† and high-risk behaviors, such as early alcohol use,^§ recent heavy alcohol use,^¶ and infrequent condom use.** Using VACS data to estimate the prevalence of HIV risk factors and identify adolescent girls and young women at elevated risk for HIV acquisition in countries like Namibia with high HIV-incidence can inform programs and policies aimed at improving the well-being of these adolescent girls and young women and help control the HIV epidemics in these countries.

What's in a Name? A Mixed Method Study on How Young Women Who Sell Sex Characterize Male Partners and Their Use of Condoms

INTRODUCTION

Young women who sell sex (YWSS) are at disproportionate risk of HIV. Reducing YWSS' vulnerability requires engaging their male sexual partners. To achieve this, we need to understand the characteristics and dynamics of their sexual partnerships to inform effective interventions.

METHODS

We conducted a mixed-methods study to compare YWSS' qualitative descriptions of male partners with categories reported in a behavioral survey. Data were drawn from enrollment into an evaluation of the DREAMS initiative in Zimbabwe in 2017. As part of a respondent-driven sampling survey, we recruited 40 seed participants from 2 intervention and 4 comparison sites. We conducted semistructured interviews with 19 "seeds," followed by a behavioral survey with 2387 YWSS. We interpreted quantitative and qualitative data together to understand how YWSS perceived male sexual partners, assess how well survey variables related to narrative descriptions, and describe patterns of risk behavior within partnerships.

RESULTS

Qualitative data suggest survey categories "husband" and "client" reflect YWSS' perceptions but "regular partner/boyfriend" and "casual partner" do not. In interviews, use of the term "boyfriend" was common, describing diverse relationships with mixed emotional and financial benefits. More than 85% of male partners provided money to YWSS, but women were less likely to report condomless sex with clients than regular partners (11% vs 37%) and more likely to report condomless sex with partners who ever forced them to have sex (37% vs 21%).

CONCLUSIONS

Reducing HIV risk among YWSS requires prevention messages and tools that recognize diverse and changing vulnerability within and between sexual relationships with different male partners.

A Systematic Review of HIV Interventions for Young Women in Sub-Saharan Africa

Adolescent girls and young women (AGYW) ages (15-24 years old) in Southern and Eastern Africa account for nearly 30% of all new HIV infections. We conducted a systematic review of studies examining the effectiveness of behavioral, structural, and combined (behavioral + structural) interventions on HIV incidence and risky sexual behaviors among AGYW. Following PRISMA guidelines, we searched PubMed, CINAHL, Web of Science, and Global Health. Twenty-two studies met inclusion criteria conducted in Eastern and Southern Africa and comprised behavioral, structural, or combined (behavioral and structural) interventions. All findings are based on 22 studies. HIV incidence was significantly reduced by one structural intervention. All three types of interventions improved condom use among AGYW. Evidence suggests that structural interventions can reduce HIV incidence, while behavioral and combined interventions require further investigation.

Correlates of Sexually Transmitted Infections Among South African Women Using Individual- and Community-Level Factors: Results from Generalized Additive Mixed Models

South Africa has the highest burden of human immunodeficiency virus (HIV) infections in the world. There is also growing evidence that an individual's risk of contracting HIV is increased by the presence of other sexually transmitted infections (STIs). The primary objective of this study was to examine the association between the prevalence of STIs in a cohort of South African women who enrolled in HIV prevention trials (2002-2012). The current study linked the individual factors with the community-level characteristics using geo-referencing. These multi-level data were analyzed in generalized additive mixed models settings. In the multivariate logistic regression model, younger age (odds ratio [OR] 4.30, 95% CI 3.20, 5.77 and OR 2.72, 95% CI 2.02, 3.66 for age < 25 and 25-29, respectively); being single/not cohabiting (OR 4.57, 95% CI 3.18, 6.53), two + sex partners (OR 1.46, 95% CI 1.18,1.80); parity < 2 (OR 2.04, 95% CI 1.53, 2.72), parity = 2 (OR 1.85, 95% CI 1.37, 2.48), and using injectables (contraceptive) (OR 1.53, 95% CI 1.13, 2.06) were all significantly associated with increased prevalence of STIs. Women who resided in the communities with high proportions of female headed-households were also significantly at higher risk for STIs (OR 1.20, p = .0025). Because these factors may reflect characteristics of the larger groups who share similar cultural norms and social environments, they can provide considerable insight into the spread of STIs. Prevention strategies based on individual and community-level drivers of STIs are likely to be the most effective means of targeting and reaching those at greatest risk of infection. This strategy has the potential to play a significant role in the epidemic's trajectory.

Increases in HIV Incidence Following Receptive Anal Intercourse Among Women: A Systematic Review and Meta-analysis

Receptive anal intercourse (RAI) carries a greater per-act risk of HIV acquisition than receptive vaginal intercourse (RVI) and may influence HIV epidemics driven by heterosexual sex. This systematic review explores the association between RAI and incident HIV among women, globally. We searched Embase and Medline through September 2018 for longitudinal studies reporting crude (cRR) or adjusted (aRR) relative risks of HIV acquisition by RAI practice among women. Of 27,563 articles identified, 17 eligible studies were included. We pooled independent study estimates using random-effects models. Women reporting RAI were more likely to acquire HIV than women not reporting RAI (pooled cRR = 1.56 95% CI 1.03–2.38, N = 18, I² = 72%; pooled aRR = 2.23, 1.01–4.92, N = 5, I² = 70%). In subgroup analyses the association was lower for women in Africa (pooled cRR = 1.16, N = 13, I² = 21%) than outside Africa (pooled cRR = 4.10, N = 5, I² = 79%) and for high-risk (pooled aRR = 1.69, N = 4, I² = 63%) than general-risk women (pooled aRR = 8.50, N = 1). Interview method slightly influenced cRR estimates (p value = 0.04). In leave-one-out sensitivity analyses pooled estimates were generally robust to removing individual study estimates. Main limitations included poor exposure definition, incomplete adjustment for confounders, particularly condom use, and use of non-confidential interview methods. More and better data are needed to explain differences in risk by world region and risk population. Women require better counselling and greater choice in prevention modalities that are effective during RVI and RAI.

Recent levels and trends in HIV incidence rates among adolescent girls and young women in ten high-prevalence African countries: a systematic review and meta-analysis

BACKGROUND

The roll-out of antiretroviral therapy (ART) has changed contexts of HIV risk, but the influence on HIV incidence among young women is not clear. We aimed to summarise direct estimates of HIV incidence among adolescent girls and young women since ART and before large investments in targeted prevention for those in sub-Saharan Africa.

METHODS

We did a systematic review and meta-analysis. We searched MEDLINE, Embase, Web of Science, Global Health, and CINAHL for studies reporting HIV incidence data from serological samples collected among females aged 15-24 years in ten countries (Kenya, Lesotho, Malawi, Mozambique, South Africa, Swaziland, Tanzania, Uganda, Zambia, and Zimbabwe) that were selected for DREAMS investment in 2015. We only included articles published in English. Our main outcome was to summarise recent levels and trends in HIV incidence estimates collected between 2005 and 2015, published or received from study authors, by age and sex, and pooled by region.

FINDINGS

51 studies were identified from nine of the ten DREAMS countries; no eligible studies from Lesotho were identified. Directly observed HIV incidence rates were lowest among females aged 13-19 years in Kumi, Uganda (0·38 cases per 100 person-years); and directly observed HIV incidence rates were highest in KwaZulu-Natal, South Africa (7·79 per 100 person-years among females aged 15-19 years, and 8·63 in those aged 20-24 years), among fishing communities in Uganda (12·40 per 100 person-years in females aged 15-19 years and 4·70 in those aged 20-24 years), and among female sex workers aged 18-24 years in South Africa (13·20 per 100 person-years) and Zimbabwe (10·80). In pooled rates from the general population studies, the greatest sex differentials were in the youngest age groups-ie, females aged 15-19 years compared with male peers in both southern African (pooled relative risk 5·94, 95% CI 3·39-10·44) and eastern African countries (3·22, 1·51-6·87), and not significantly different among those aged 25-29 years in either region. Incidence often peaked earlier (during teenage years) among high-risk groups compared with general populations. Since 2005, HIV incidence among adolescent girls and young women declined in Rakai (Uganda) and Manicaland (Zimbabwe), and also declined among female sex workers in Kenya, but not in the highest-risk communities in South Africa and Uganda.

INTERPRETATION

Few sources of direct estimates of HIV incidence exist in high-burden countries and trend analyses with disaggregated data for age and sex are rare but indicate recent declines among adolescent girls and young women. In some of the highest-risk settings, however, little evidence exists to suggest ART availability and other efforts slowed transmission by 2016. Despite wide geographical diversity in absolute levels of incidence in adolescent girls and young women, risk relative to males persisted in all settings, with the greatest sex differentials in the youngest age groups. To end new infections among the growing population of adolescents in sub-Saharan Africa, prevention programmes must address gender inequalities driving excessive risk among adolescent girls.

FUNDING

This work was conducted as part of a planning grant funded by the Bill & Melinda Gates Foundation.

Targeted Pregnancy and Human Immunodeficiency Virus Prevention Risk-Reduction Counseling for Young Women: Lessons Learned from Biomedical Prevention Trials

Background

Women enrolled in human immunodeficiency virus (HIV) prevention efficacy trials receive counseling on prevention of HIV, sexually transmitted infections (STIs), and pregnancy during every visit. Incident pregnancy has an impact on efficacy outcomes. Incidence rates of pregnancy and HIV/STIs among women who became pregnant and associated risk factors were assessed.

Methods

Data from 9165 women participating in HIV prevention trials in KwaZulu-Natal, South Africa from 2002-2012 were combined. Demographic and behavioral predictors of incidence pregnancy and incidence HIV and STIs were determined using Cox regression models.

Results

Overall pregnancy incidence was 9.6 per 100 person-year (py) (95% confidence interval [Cl], 9.1-10.3). Human immunodeficiency virus incidence among pregnant women was 5.93 per 100 py (95% Cl, 4.73-7.44). Incidence of STIs among pregnant women for Chlamydia trachomatis, Trichomonas vaginalis, Neisseria gonorrhoeae, and Treponema pallidum (syphilis) were 10.87, 7.42, 3.92, and 1.43 per 100 py, respectively. In the adjusted analyses, we observed overlapping risk factors for HIV acquisition during pregnancy, ie, young age, not married/not cohabitating, and low parity. The risk of pregnancy and HIV acquisition is more than 3 times higher among young women (<20 years of age).

Conclusions

We identified overlapping risk factors for pregnancy and HIV incidence, suggesting an urgent need for appropriate, targeted, individual-centred counseling for women participating in HIV prevention trials.

Factors associated with vaccination completion and retention among HIV negative female sex workers enrolled in a simulated vaccine efficacy trial in Kampala, Uganda

BACKGROUND

Female sex workers (FSWs) at substantial risk of HIV are potentially a suitable group for HIV prevention trials including vaccine trials. Few HIV vaccine preparatory studies have been conducted among FSWs in Sub-Saharan Africa (SSA); data are therefore limited on acceptability of vaccine trial procedures. We determined vaccination completion and one-year retention among FSWs in Kampala, Uganda.

METHODS

We conducted a prospective study that simulated a vaccine efficacy trial among HIV negative FSWs (18-49 years). Hepatitis B vaccine (Engerix B) was used to mimic an HIV vaccine product. Volunteers received 1 ml intramuscular injection at 0, 1 and 6 months, and made additional visits (3 days post-vaccination and months 3, 9 and 12). They were censored at that visit if diagnosed as HIV positive or pregnant. We collected socio-demographic, behavioral and clinical data at baseline, 6 and 12 months and fitted Poisson regression models with robust standard error to find factors associated with vaccination completion and retention.

RESULTS

We enrolled 290 volunteers (median age 27 years) of whom 230 reached a study end-point as follows: 7 became HIV infected, 11 became pregnant and 212 completed both the vaccination schedule and 12-month visit giving a retention of 77.9% (212/272). Vaccination completion was 82.4%. Non-retention at 1 year was more likely among those reporting symptoms of genital ulcer disease (GUD) in the past 3 months (IRR 1.90; 95% CI 1.09-3.32) and those < 35 years; (IRR 6.59; 95% CI 2.11-20.57). Non-completion of the vaccination schedule was associated with being < 35 years (IRR 13.10; 95% CI 1.89-90.92, reporting GUD symptoms (IRR 3.02; 95% CI 1.71-5.33) and reporting consistent condom use with new sexual partners (IRR 2.57; 95% CI 1.10-6.07).

CONCLUSIONS

FSWs are at substantial risk of HIV infection and yet willing to participate in HIV vaccine and prevention research; young FSWs should be empowered, and those reporting GUD symptoms need close follow up to improve participation in future HIV vaccine trials.

Viral suppression among persons living with HIV in Trinidad & Tobago: Implications for targeted prevention programmes

In Trinidad and Tobago, despite persons living with HIV (PLHIV) having access to subsidised treatment and care, only 47% PLHIV attain viral suppression. The study assessed the role of individual-level factors on viral suppression among PLHIV in Trinidad and Tobago. Data from 9,629 PLHIV who attended an HIV clinic between 2016 and 2018 were analysed. Cases were aged ≥18 who met the CDC HIV case definition. Viral suppression defined as a viral load of <200 copies/ml at last assessment. The chi-square test of association determined statistically significant relationships between individual factors and viral suppression. Logistic regression was used to estimate odds ratios (OR) for viral suppression. PLHIV who were males (OR = 0.76, 95% CI 0.67-0.87), men who have sex with men (MSM) (OR = 0.82, 95% CI 0.67-0.99), single/unmarried (OR = 0.69, 95% CI 0.55-0.87), aged 18-24 years (OR = 0.66, 95% CI 0.49-0.89), aged 25-49 years (OR = 0.81, 95% CI 0.70-0.94) were less likely to achieve viral suppression. These study findings demonstrate that retention/adherence programmes must urgently identify and target vulnerable PLHIV populations in Trinidad and Tobago to improve viral suppression. Further research examining community and societal factors, such as stigma and discrimination, is warranted.

Association of endogenous progesterone levels in young women using hormonal contraception with recent HIV-1 infection

BACKGROUND

A high endogenous progesterone luteal state in the menstrual cycle has been independently associated with Human Immunodeficiency Virus (HIV) incidence in epidemiological studies. Hormonal contraception particularly high dose Depot Medroxyprogesterone Acetate (DMPA) is also thought to increase the risk of HIV acquisition. Inconsistent reports of this association have led us to hypothesize that unsuppressed endogenous progesterone level in women who reported hormonal contraception (HC) use may be an explanation for increased vulnerability to HIV.

METHODS

This pilot study was a secondary cross-sectional analysis of data and laboratory testing of stored specimens collected from women who participated in the SAMRC HIV prevention MDP 301 trial during 2005-2009 in South Africa. Serum progesterone levels were measured in 39 women at the point of first positive HIV diagnosis during study follow-up and 36 women who remained HIV uninfected at the 52-week study exit visit.

RESULTS

Overall, the median (IQR) progesterone level in 49 women using hormonal contraception was 0.39 ng/ml (IQR 0.13-0.45) and 48 (97.9%) women had a progesterone level < 3.0 ng/ml suggestive of adequate progesterone suppression for contraceptive efficacy. After excluding the one woman with a progesterone level of > 3.0 ng/ml, the median progesterone level in women using DMPA remained marginally higher at 0.42 ng/ml (IQR 0.27-0.45) than women using Norethisterone Enanthate (NET-EN) (0.31 ng/ml; IQR 0.13-0.41, p = 0.061). For women using hormonal contraception, the median progesterone level did not differ between women with recent HIV infection or women who remained HIV negative (0.39 vs 0.38 ng/ml, p = 0.959). Similarly, the median progesterone level in women using DMPA or NET-EN did not differ by HIV status (0.43 vs 0.41 ng/ml, p = 0.905; 0.24 vs 0.31 ng/ml, p = 0.889).

CONCLUSION

Among women using hormonal contraception, DMPA or NET-EN we did not observe a significant difference in progesterone levels between women with recently acquired HIV infection and women who remained HIV negative. Our findings suggest that endogenous progesterone levels remain suppressed in the presence of hormonal contraception and are not likely to be associated with HIV acquisition.

Does Incident Circumcision Lead to Risk Compensation? Evidence From a Population Cohort in KwaZulu-Natal, South Africa

BACKGROUND

Voluntary medical male circumcision reduces men's risk of HIV acquisition and may thus increase HIV risk-related sexual behaviors through risk compensation. We analyze longitudinal data from one of Africa's largest population cohorts using fixed-effects panel estimation to measure the effect of incident circumcision on sexual behaviors.

SETTING

KwaZulu-Natal, South Africa.

METHODS

An open population cohort of men was followed from 2009 to 2015. Men self-reported their circumcision status and sexual behavior annually. We used linear regression models with individual-level fixed effects to measure the effect of incident circumcision on recent sex (past 12 months) and sexual behaviors that increase HIV risk (not using a condom at last sex, never using condoms with the most recent sexual partner, concurrent sexual partners at present, and multiple sexual partners in the past 12 months). We controlled for potential time-varying confounders: calendar year, age, education, and sexual debut.

RESULTS

The 5127 men in the cohort had a median age of 18 years (interquartile range 16-24) at cohort entry. Over the study period, almost 1 in 5 of these men (19.4%) became newly circumcised. Incident circumcision affected neither recent sex [percentage point (PP) change 0.0, 95% confidence interval: -1.2 to 1.3] nor sexual behaviors that increase HIV risk (PP -1.6, 95% confidence interval: -4.5 to 1.4).

CONCLUSIONS

The data from this study strongly reject the hypothesis that circumcision affects sexual risk-taking. Risk compensation should not serve as an argument against increased and accelerated scale-up of circumcision in this and similar communities in South Africa.

Sociobehavioral and community predictors of unsuppressed HIV viral load: multilevel results from a hyperendemic rural South African population

OBJECTIVE

Extensive antiretroviral therapy scale-up is expected to prevent onward transmission of HIV by reducing the overall community viral load. Despite multiple studies about predictors of detectable viral load derived from clinical setting, to date, no study has established such predictors using a population-based viral load survey in a sub-Saharan African hyperendemic setting to inform interventions designed to halt HIV transmission. We used one of Africa's largest prospective cohorts in rural KwaZulu-Natal Province, South Africa, to establish the key sociodemographic, behavioral and community predictors of unsuppressed viral load at the population level.

METHODS

We collected 5454 viral load measurements from a population-based viral load survey of 3892 women living with HIV from a rural population during 2011, 2013 and 2014. Multilevel logistic regression models were fitted to examine the risk predictors of unsuppressed viral load.

RESULTS

Among women living with HIV in this population, the prevalence of unsuppressed viral load was 69% in 2011, 58% in 2013 and 53% in 2014. Although time since HIV infection was associated with lower risk for virologic detection [adjusted odds ratio (aOR) = 0.91,0.87-0.94], young women (aOR = 2.59,1.47-4.55) with extensive external migration history (aOR = 1.25,1.02-1.54), greater number of sexual partners (aOR = 1.30,1.02-1.67), and longer history of residing in an HIV incidence hotspot community were more likely to experience unsuppressed viral load (aOR = 1.12,1.06-1.19).

CONCLUSION

Young women, number of sexual partners, transiency and longer residence in an HIV hotspot community are important determinants of unsuppressed viral load in a hyperendemic rural African setting. To substantially reduce the persistently high transmission potential in these settings, targeted interventions to address these risk factors will be essential for both individual and population health gains.

Incidence of unintended pregnancy among female sex workers in low-income and middle-income countries: a systematic review and meta-analysis

OBJECTIVES

To determine the incidence of unintended pregnancy among female sex workers (FSWs) in low-income and middle-income countries (LMICs).

DESIGN

We searched MEDLINE, PsychInfo, Embase and Popline for papers published in English between January 2000 and January 2016, and Web of Science and Proquest for conference abstracts. Meta-analysis was performed on the primary outcomes using random effects models, with subgroup analysis used to explore heterogeneity.

PARTICIPANTS

Eligible studies targeted FSWs aged 15-49 years living or working in an LMIC.

OUTCOME MEASURES

Studies were eligible if they provided data on one of two primary outcomes: incidence of unintended pregnancy and incidence of pregnancy where intention is undefined. Secondary outcomes were also extracted when they were reported in included studies: incidence of induced abortion; incidence of birth; and correlates/predictors of pregnancy or unintended pregnancy.

RESULTS

Twenty-five eligible studies were identified from 3866 articles. Methodological quality was low overall. Unintended pregnancy incidence showed high heterogeneity (I²>95%), ranging from 7.2 to 59.6 per 100 person-years across 10 studies. Study design and duration were found to account for heterogeneity. On subgroup analysis, the three cohort studies in which no intervention was introduced had a pooled incidence of 27.1 per 100 person-years (95% CI 24.4 to 29.8; I²=0%). Incidence of pregnancy (intention undefined) was also highly heterogeneous, ranging from 2.0 to 23.4 per 100 person-years (15 studies).

CONCLUSIONS

Of the many studies examining FSWs' sexual and reproductive health in LMICs, very few measured pregnancy and fewer assessed pregnancy intention. Incidence varied widely, likely due to differences in study design, duration and baseline population risk, but was high in most studies, representing a considerable concern for this key population. Evidence-based approaches that place greater importance on unintended pregnancy prevention need to be incorporated into existing sexual and reproductive health programmes for FSWs.

PROSPERO REGISTRATION NUMBER

CRD42016029185.

Sexual behavior experiences and characteristics of male-female partnerships among HIV positive adolescent girls and young women: Qualitative findings from Zimbabwe

Background

New HIV infections among sub-Saharan Africa's adolescent girls and young women (AGYW, ages 15–24) greatly exceed those of their male peers. In addition, AGYW tend to acquire HIV at a much earlier age. Understanding the factors associated with HIV infection in AGYW could inform effective prevention and treatment interventions for these populations and their male sexual partners.

Methods

This qualitative study, conducted October-November 2016, was a follow on to a quantitative survey that sought to characterize male sexual partners and sexual behaviors of sexually active HIV positive AGYW in Zimbabwe. The qualitative study explored sexual behavior experiences and characteristics of male-female partnerships among the same participants. We conducted in-depth interviews with purposively sampled AGYW (16–24 years). Audio recorded qualitative data were transcribed, translated into English, and thematically coded using NVivo.

Results

28 AGYW (n = 14 urban, n = 14 rural) took part in the in-depth interviews. 50% were 16–19 years old. Discussions with 10/11 (91%) AGYW who were reportedly infected through sex suggested that they had acquired HIV from their husbands or romantic partners. Accounts also suggested that the age difference between respondents and their male sexual partners was ≥5 years. Overall, respondents described two types of male partners: those older (''sugar daddies'', men ≥35 years old) and younger (<35 years). Respondents felt unable to suggest condom use to both older and younger partners. Evident in respondents' accounts was a general low HIV risk perception, particularly with younger men, which was largely due to poor HIV knowledge. Discussions suggested that an AGYW's relationship with either male partner was characterized by some form of violence.

Conclusions

Discussions highlighted the nature and characteristics of relationships between AGYW and their male sexual partners. Findings could inform interventions to engender risk perception among AGYW, promote female-controlled HIV prevention efforts and, foster risk-reduction among men.

Anal Intercourse Among Female Sex Workers in Côte d'Ivoire: Prevalence, Determinants, and Model-Based Estimates of the Population-Level Impact on HIV Transmission

Current evidence suggests that anal intercourse (AI) during sex work is common in sub-Saharan Africa, but there have been few studies in which the contribution of heterosexual AI to human immunodeficiency virus (HIV) epidemics has been investigated. Using a respondent-driven sampling survey of female sex workers (FSWs; n = 466) in Abidjan, Côte d'Ivoire, in 2014, we estimated AI prevalence and frequency. Poisson regressions were used to identify AI determinants. Approximately 20% of FSWs engaged in AI during a normal week (95% confidence interval: 15, 26). Women who performed AI were generally younger, had been selling sex for longer, were born in Côte d'Ivoire, and reported higher sex-work income, more frequent sex in public places, and violence from clients than women not reporting AI. Condom use was lower, condom breakage/slippage more frequent, and use of water-based lubricants was less frequently reported for AI than for vaginal intercourse. Using a dynamic transmission model, we estimated that 22% (95% credible interval: 11, 37% of new HIV infections could have been averted among FSWs during 2000-2015 if AI had been substituted for vaginal intercourse. Despite representing a small fraction of all sex acts, AI is an underestimated source of HIV transmission. Increasing availability and uptake of condoms, lubricants, and pre-exposure prophylaxis for women engaging in AI could help mitigate HIV risk.

Social inequalities and the context of vulnerabilities: HIV/AIDS awareness and prevention knowledge among married women

Worldwide, socioeconomically disadvantaged women bear disproportionate risks of HIV infection. To examine if the individual and community-level socioeconomic disadvantages further increase their vulnerabilities, we used Bangladesh Demographic and Health Surveys. Between 2004 and 2014, we found pronounced disparities in HIV/AIDS prevention knowledge among women based on their socioeconomic status and community context. We observed substantial growth of knowledge among all women while the greatest growth occurred among those living in the disadvantaged communities. There is a need for greater understanding of the social determinants to develop and implement HIV/AIDS education programs that would benefit all segments of the population.

Incidence rate estimation, periodic testing and the limitations of the mid-point imputation approach

Background

It is common to use the mid-point between the latest-negative and earliest-positive test dates as the date of the infection event. However, the accuracy of the mid-point method has yet to be systematically quantified for incidence studies once participants start to miss their scheduled test dates.

Methods

We used a simulation-based approach to generate an infectious disease epidemic for an incidence cohort with a high (80-100%), moderate (60-79.9%), low (40-59.9%) and poor (30-39.9%) testing rate. Next, we imputed a mid-point and random-point value between the participant's latest-negative and earliest-positive test dates. We then compared the incidence rate derived from these imputed values with the true incidence rate generated from the simulation model.

Results

The mid-point incidence rate estimates erroneously declined towards the end of the observation period once the testing rate dropped below 80%. This decline was in error of approximately 9%, 27% and 41% for a moderate, low and poor testing rate, respectively. The random-point method did not introduce any systematic bias in the incidence rate estimate, even for testing rates as low as 30%.

Conclusions

The mid-point assumption of the infection date is unjustified and should not be used to calculate the incidence rate once participants start to miss the scheduled test dates. Under these conditions, we show an artefactual decline in the incidence rate towards the end of the observation period. Alternatively, the single random-point method is straightforward to implement and produces estimates very close to the true incidence rate.

Changing Dynamics of HIV Transmission in Côte d'Ivoire: Modeling Who Acquired and Transmitted Infections and Estimating the Impact of Past HIV Interventions (1976-2015)

INTRODUCTION

Understanding the impact of past interventions and how it affected transmission dynamics is key to guiding prevention efforts. We estimated the population-level impact of condom, antiretroviral therapy (ART), and prevention of mother-to-child transmission activities on HIV transmission and the contribution of key risk factors on HIV acquisition and transmission.

METHODS

An age-stratified dynamical model of sexual and vertical HIV transmission among the general population, female sex workers (FSW), and men who have sex with men was calibrated to detailed prevalence and intervention data. We estimated the fraction of HIV infections averted by the interventions, and the fraction of incident infections acquired and transmitted by different populations over successive 10-year periods (1976-2015).

RESULTS

Overall, condom use averted 61% (95% credible intervals: 56%-66%) of all adult infections during 1987-2015 mainly because of increased use by FSW (46% of infections averted). In comparison, ART prevented 15% (10%-19%) of adult infections during 2010-2015. As a result, FSW initially (1976-1985) contributed 95% (91%-97%) of all new infections, declining to 19% (11%-27%) during 2005-2015. Older men and clients mixing with non-FSW are currently the highest contributors to transmission. Men who have sex with men contributed ≤4% transmissions throughout. Young women (15-24 years; excluding FSW) do not transmit more infections than they acquired.

CONCLUSIONS

Early increases in condom use, mainly by FSW, have substantially reduced HIV transmission. Clients of FSWs and older men have become the main source of transmission, whereas young women remain at increased risk. Strengthening prevention and scaling-up of ART, particularly to FSW and clients of female sex workers, is important.

A review of transition experiences in perinatally and behaviourally acquired HIV-1 infection; same, same but different?

Introduction: Despite sharing common psychosocial and developmental experiences, adolescents living with perinatally and behaviourally acquired HIV-1 infection are different in terms of timing of HIV infection and developmental stage at infection. Therefore, it is of interest to identify similarities and differences between these two groups of adolescents living with HIV in their experiences, facilitators and barriers during the transition process.

Methods: A detailed literature search of peer-reviewed published papers was conducted on PubMed to identify relevant original research or viewpoints published up to September 2016. Conference abstracts and other unpublished data sources were not included.

Results: Existing published literature, mainly using qualitative methods, explores the transition from paediatric to adult healthcare provision, as experienced by these two groups of young people. Reports highlight the variation and similarities in their experiences and challenges of transition. Findings from the USA and Europe predominate, while experience from Africa and Asia is lacking, despite the importance of these regions in the global epidemic.

Conclusions: Published transition data remain limited, and there are few studies focusing on behaviourally infected adolescents and key population groups (e.g. adolescents who use drugs, lesbian/gay/transgender individuals). Robust definitions of the transition process and standardized outcome measures are required to facilitate cross-study and geographic comparisons.

Incident HIV during pregnancy and early postpartum period: a population-based cohort study in a rural area in KwaZulu-Natal, South Africa

BACKGROUND

The evidence on the effect of pregnancy on acquiring HIV is conflicting, with studies reporting both higher and lower HIV acquisition risk during pregnancy when prolonged antiretroviral therapy was accessible. The aim of this study was to assess the pregnancy effect on HIV acquisition where antiretroviral therapy was widely available in a high HIV prevalence setting.

METHODS

This is a retrospective cohort study nested within a population-based surveillance to determine HIV incidence in HIV-uninfected women from 15 to 49 years from 2010 through 2015 in rural KwaZulu-Natal. HIV incidence per 100 person-years according to pregnancy status (not pregnant, pregnant, to eight weeks postpartum) were measured in 5260 HIV-uninfected women. Hazard ratios (HR) were estimated by Cox proportional hazards regression with pregnancy included as a time varying variable.

RESULTS

Overall, pregnancy HIV incidence was 4.5 per 100 person-years (95% CI 3.4-5.8), higher than non-pregnancy (4.0; 95% CI 3.7-4.3) and postpartum incidences (4.2 per 100 person-years; 95% CI 2.3-7.6). However, adjusting for age, and demographic factors, pregnant women had a lower risk of acquiring HIV (HR 0.4; 95% CI 0.2-0.9, P = 0.032) than non-pregnant women; there were no differences between postpartum and non-pregnant women (HR 1.2; 95% CI 0.4-3.2; P = 0.744). In models adjusting for the interaction of age and gravidity, pregnant women under 25 years with two or more pregnancies had a 2.3 times greater risk of acquiring HIV than their older counterparts (95% CI 1.3-4.3; P = 0.008).

CONCLUSIONS

Pregnancy had a protective effect on HIV acquisition. Elevated HIV incidence in younger women appeared to be driven by those with higher gravidity. The sexual and biological factors in younger women should be explored further in order to design appropriate HIV prevention interventions.

Population-level impact of an accelerated HIV response plan to reach the UNAIDS 90-90-90 target in Côte d'Ivoire: Insights from mathematical modeling

BACKGROUND

National responses will need to be markedly accelerated to achieve the ambitious target of the Joint United Nations Programme on HIV/AIDS (UNAIDS). This target aims for 90% of HIV-positive individuals to be aware of their status, for 90% of those aware to receive antiretroviral therapy (ART), and for 90% of those on treatment to have a suppressed viral load by 2020, with each individual target reaching 95% by 2030. We aimed to estimate the impact of various treatment-as-prevention scenarios in Côte d'Ivoire, one of the countries with the highest HIV incidence in West Africa, with unmet HIV prevention and treatment needs, and where key populations are important to the broader HIV epidemic.

METHODS AND FINDINGS

An age-stratified dynamic model was developed and calibrated to epidemiological and programmatic data using a Bayesian framework. The model represents sexual and vertical HIV transmission in the general population, female sex workers (FSW), and men who have sex with men (MSM). We estimated the impact of scaling up interventions to reach the UNAIDS targets, as well as the impact of 8 other scenarios, on HIV transmission in adults and children, compared to our baseline scenario that maintains 2015 rates of testing, ART initiation, ART discontinuation, treatment failure, and levels of condom use. In 2015, we estimated that 52% (95% credible intervals: 46%-58%) of HIV-positive individuals were aware of their status, 72% (57%-82%) of those aware were on ART, and 77% (74%-79%) of those on ART were virologically suppressed. Reaching the UNAIDS targets on time would avert 50% (42%-60%) of new HIV infections over 2015-2030 compared to 30% (25%-36%) if the 90-90-90 target is reached in 2025. Attaining the UNAIDS targets in FSW, their clients, and MSM (but not in the rest of the population) would avert a similar fraction of new infections (30%; 21%-39%). A 25-percentage-point drop in condom use from the 2015 levels among FSW and MSM would reduce the impact of reaching the UNAIDS targets, with 38% (26%-51%) of infections averted. The study's main limitation is that homogenous spatial coverage of interventions was assumed, and future lines of inquiry should examine how geographical prioritization could affect HIV transmission.

CONCLUSIONS

Maximizing the impact of the UNAIDS targets will require rapid scale-up of interventions, particularly testing, ART initiation, and limiting ART discontinuation. Reaching clients of FSW, as well as key populations, can efficiently reduce transmission. Sustaining the high condom-use levels among key populations should remain an important prevention pillar.

Antiretroviral Therapy to Prevent HIV Acquisition in Serodiscordant Couples in a Hyperendemic Community in Rural South Africa

We assessed the role of antiretroviral therapy (ART) on human immunodeficiency virus (HIV) acquisition in serodiscordant couples in KwaZulu-Natal, South Africa. ART use was associated with a 77% reduction in HIV acquisition risk, suggesting ART is highly effective for prevention in population-based settings.

Background. Antiretroviral therapy (ART) was highly efficacious in preventing human immunodeficiency virus (HIV) transmission in stable serodiscordant couples in the HPTN-052 study, a resource-intensive randomized controlled trial with near-perfect ART adherence and mutual HIV status disclosure among all participating couples. However, minimal evidence exists of the effectiveness of ART in preventing HIV acquisition in stable serodiscordant couples in “real-life” population-based settings in hyperendemic communities of sub-Saharan Africa, where health systems are typically resource-poor and overburdened, adherence to ART is often low, and partners commonly do not disclose their HIV status to each other.

Methods. Data arose from a population-based open cohort in KwaZulu-Natal, South Africa. A total of 17 016 HIV-uninfected individuals present between January 2005 and December 2013 were included. Interval-censored time-updated proportional hazards regression was used to assess how the ART status affected HIV transmission risk in stable serodiscordant relationships.

Results. We observed 1619 HIV seroconversions in 17 016 individuals, over 60 349 person-years follow-up time. During the follow-up period, 1846 individuals had an HIV-uninfected and 196 had an HIV-infected stable partner HIV incidence was 3.8/100 person-years (PY) among individuals with an HIV-infected partner (95% confidence interval [CI], 2.3–5.6), 1.4/100 PY (.4–3.5) among those with HIV-infected partners receiving ART, and 5.6/100 PY (3.5–8.4) among those with HIV-infected partners not receiving ART. Use of ART was associated with a 77% decrease in HIV acquisition risk among serodiscordant couples (adjusted hazard ratio, 0.23; 95% CI, .07–.80).

Conclusions. ART initiation was associated with a very large reduction in HIV acquisition in serodiscordant couples in rural KwaZulu-Natal. However, this “real-life” effect was substantially lower than the effect observed in the HPTN-052 trial. To eliminate HIV transmission in serodiscordant couples, additional prevention interventions are probably needed.

Individual and Population Level Impact of Key HIV Risk Factors on HIV Incidence Rates in Durban, South Africa

We aimed to estimate the individual and joint impact of age, marital status and diagnosis with sexually transmitted infections (STIs) on HIV acquisition among young women at a population level in Durban, KwaZulu-Natal, South Africa. A total of 3,978 HIV seronegative women were recruited for four biomedical intervention trials from 2002-2009. Point and interval estimates of partial population attributable risk (PAR) were used to quantify the proportion of HIV seroconversions which can be prevented if a combination of risk factors is eliminated from a target population. More than 70% of the observed HIV acquisitions were collectively attributed to the three risk factors: younger age (<25 years old), unmarried and not cohabiting with a stable/regular partner and diagnosis with STIs. Addressing these risks requires targeted structural, behavioural, biomedical and cultural interventions in order to impact on unacceptably high HIV incidence rates among young women and the population as a whole.

Killer-cell Immunoglobulin-like Receptor (KIR) gene profiles modify HIV disease course, not HIV acquisition in South African women

BACKGROUND

Killer-cell Immunoglobulin-like Receptors (KIR) interact with Human Leukocyte Antigen (HLA) to modify natural killer- and T-cell function. KIR are implicated in HIV acquisition by small studies that have not been widely replicated. A role for KIR in HIV disease progression is more widely replicated and supported by functional studies.

METHODS

To assess the role of KIR and KIR ligands in HIV acquisition and disease course, we studied at-risk women in South Africa between 2004-2010. Logistic regression was used for nested case-control analysis of 154 women who acquired vs. 155 who did not acquire HIV, despite high exposure. Linear mixed-effects models were used for cohort analysis of 139 women followed prospectively for a median of 54 months (IQR 31-69) until 2014.

RESULTS

Neither KIR repertoires nor HLA alleles were associated with HIV acquisition. However, KIR haplotype BB was associated with lower viral loads (-0.44 log10 copies/ml; SE = 0.18; p = 0.03) and higher CD4+ T-cell counts (+80 cells/μl; SE = 42; p = 0.04). This was largely explained by the protective effect of KIR2DL2/KIR2DS2 on the B haplotype and reciprocal detrimental effect of KIR2DL3 on the A haplotype.

CONCLUSIONS

Although neither KIR nor HLA appear to have a role in HIV acquisition, our data are consistent with involvement of KIR2DL2 in HIV control. Additional studies to replicate these findings are indicated.

Human papillomavirus prevalence in South African women and men according to age and human immunodeficiency virus status

BACKGROUND

Both cervical cancer and human immunodeficiency virus (HIV) are major public health problems in Sub-Saharan Africa. The objectives of the study were to investigate human papillomavirus (HPV) prevalence according to age, HIV status and gender.

METHODS

Participants were 208 HIV-negative women, 278 HIV-positive women, 325 HIV-negative men and 161 HIV-positive men between the ages of 18-66 years. HPV types were determined in cervical and penile cells by Roche Linear Array HPV genotyping assay.

RESULTS

HPV prevalence was 36.7 % (76/207; 95 % confidence intervals (CI): 30.4-43.4 %) in HIV-negative women, with the highest prevalence of 61.0 % (25/41; 95 % CI: 45.7-74.4 %) in women aged 18-25 years. HPV prevalence was 74.0 % (205/277; 95 % CI: 68.5-78.8 %) in HIV-positive women, with the highest prevalence of 86.4 % (38/44; 95 % CI: 72.9-94.0 %) in women aged 18-25 years. HPV prevalence was found to decrease with increasing age in HIV-negative women (P = 0.0007), but not in HIV-positive women (P = 0.898). HPV prevalence was 50.8 % (159/313; 95 % CI: 45.3-56.3 %) in HIV-negative men, with the highest prevalence of 77.0 % (27/35; 95 % CI: 60.7-88.2 %) in men aged 18-25 years. HPV prevalence was 76.6 % (121/158; 95 % CI: 69.2-82.9 %) in HIV-positive men, with the highest prevalence of 87.5 % (7/8; 95 % CI: 50.8-99.9 %) in men 18-25 years of age. HPV prevalence was found to decrease with increasing age in HIV-negative men (P = 0.004), but not in HIV-positive men (P = 0.385). HIV-positive women had a significantly higher prevalence of one or more HPV type(s) in the bivalent (HPV-16/18: 20 % 55/277, 9 % 12/207; P <0.001), quadrivalent (HPV-6/11/16/18: 26 % 71/277, 12 % 24/207; P = 0.001) and nonavalent vaccine (HPV-6/11/16/18/31/33/52/56/58: 65 % 181/277, 24 % 50/207; P <0.001) compared to HIV-negative women. Similar observation were observed in men for bivalent (20 % 32/158, 10 % 30/313; P = 0.001), quadrivalent (35 % 56/158, 13 % 41/313; P <0.001) and nonavalent vaccine (75 % 119/158, 28 % 87/313; P <0.001).

CONCLUSIONS

This study demonstrated high HPV prevalence among HIV-positive women and men in all age groups. The high prevalence of HPV types found in bivalent, quadrivalent and nonavalent vaccines in South African HIV-positive and HIV-negative women and men demonstrate that this population will greatly benefit from current HPV vaccines.