Sexual mixing patterns and sex-differentials in teenage exposure to HIV infection in rural Zimbabwe

Intimate partner violence, behaviours associated with risk of HIV acquisition and condom use in married women in Manicaland, East Zimbabwe: An HIV prevention cascade analysis

BACKGROUND

Intimate partner violence (IPV) is widespread in the WHO African region with generalised HIV epidemics and may contribute to ongoing HIV transmission through its associations with behaviours associated with HIV acquisition risk and low use of prevention methods particularly in marital relationships.

METHODS

We conducted a male condom HIV prevention cascade analysis using data from a general-population survey in Manicaland, Zimbabwe (July 2018-December 2019) to develop an understanding of how interventions that reduce IPV might be built upon to also reduce HIV incidence. Multivariable logistic regression was used to measure associations between currently-married HIV-negative women's experience of IPV and: (1) being in the priority population for HIV prevention methods (i.e. married women engaging in behaviours associated with HIV acquisition risk or with a spouse who engages in similar behaviours or is living with HIV), and (2) male condom use by women in this priority population. Male condom HIV prevention cascades, with explanatory barriers for gaps between successive cascade bars (motivation, access and effective use), were compared for women in the priority population reporting and not reporting IPV.

RESULTS

We found a positive association between IPV and being in the priority population for HIV prevention methods (72.3% versus 58.5%; AOR = 2.26, 95% CI:1.74-2.93). Condom use was low (< 15%) for women in the priority population and did not differ between those reporting and not reporting IPV. The HIV prevention cascades for women reporting and not reporting IPV were similar; both showing large gaps in motivation and capacity to use male condoms effectively. Women reporting motivation and access to male condoms were more likely to report their partner being a barrier to condom use if they experienced IPV (84.8% versus 75.5%; AOR = 2.25, 95% CI:1.17-4.31).

CONCLUSION

The findings of this study support the case for trials of integrated IPV/HIV prevention interventions that are tailored to improve HIV risk perception among HIV-negative married women and to make condom provision more acceptable for this group.

The impact of COVID-19 on sexual risk behaviour for HIV acquisition in east Zimbabwe: An observational study

The Covid-19 pandemic and associated restrictions have the potential to alter sexual risk behaviours for HIV acquisition with important implications for HIV prevention programmes in sub-Saharan Africa. To date, no large-scale data have been published to substantiate hypothesised changes in sexual risk behaviours. We used longitudinal survey data to assess the impact of Covid-19 on sexual risk behaviours in east Zimbabwe. Data on sexual behaviours in HIV-negative adults aged 15-54 years were collected in two rounds of a general population open-cohort survey conducted in Manicaland, Zimbabwe shortly before (July 2018 to December 2019; N = 7316) and several months into the Covid-19 epidemic (February to July 2021; N = 6356). Descriptive statistics and logistic regression models of serial cross-sectional and prospective cohort data were used to assess changes in sexual risk behaviours. The proportion of females aged 15-19 years reporting sexual debut declined from 29.7% before Covid-19 to 20.3% during Covid-19 (adjusted odds ratio (AOR) = 0.49, 95% confidence interval (95% CI), 0.38-0.63). Fewer sexually-active females reported multiple sexual partners during Covid-19 (3.35% versus 6.07%; AOR = 0.55, 95% CI, 0.43-0.72). No population-level changes in male behaviour between survey rounds were recorded but the cohort analysis revealed a complex pattern of behaviour change with HIV risk behaviours increasing for some individuals and decreasing for others. Overall HIV risk behaviours remained high in a sub-Saharan African population with a generalised HIV epidemic over a period of Covid-19 lockdowns when movements and social contacts were restricted.

Timing of sexual debut and associated sociodemographic and HIV risk factors among young people in Eswatini

Young people in sub-Saharan Africa and specifically in Eswatini (previously Swaziland), continue to be disproportionately affected by HIV despite having equitable access to antiretroviral treatment. Early sexual debut is one of the many factors linked to HIV infection that is discussed in the context of general public health. Monitoring this behavior is essential for developing preventative, evidence-based interventions. This study aims to describe the early and/or typical sexual debut among young people in Eswatini and examines sociodemographic and HIV risk factors associated with early and typical sexual debut timing. We analyzed cross-sectional secondary data from the 2016/17 Swaziland HIV Incidence Measurement Survey (SHIMS), which had a representative sample of 2,383 young people aged 18-24. Respondents were selected using a two-stage stratified probability sampling design. We applied descriptive statistics and multivariable multinomial logistic regressions to examine the data. Out of the 2,383 respondents, 71.3% had sexual experience, with 4.1% and 26.5% reporting early sexual debut (<15 years) and typical sexual debut (<18 years), respectively. Our study found that age, sex, education, marital status, wealth, sexual partners in the past 12 months, and alcohol use were significantly associated with early and/or typical sexual debut. It is crucial to consider the sociodemographic factors and HIV risk factors of young people when designing programs and interventions aimed at preventing early sexual debut or transition. This approach is necessary to promote better sexual and reproductive health in alignment with sustainable development goals.

Age-disparate and intergenerational sex partnerships and HIV: the role of gender norms among adolescent girls and young women in Malawi

BACKGROUND

Age-mixing (age-disparate [5-9 years difference] and intergenerational [≥ 10 years difference]) partnerships are hypothesized drivers of HIV in adolescent girls and young women (AGYW; 15-24 years). These partnerships are often associated with increased gender inequities which undermine women's agency and assertiveness. We assessed whether age-mixing partnerships were associated with HIV in Malawi and if endorsement of inequitable gender norms modifies this relationship.

METHODS

We analyzed data from the Malawi Population-based HIV Impact Assessment, a nationally representative household survey conducted in 2015-2016. Participants underwent HIV testing and completed questionnaires related to actively endorsed gender norms and sexual risk behavior. We used multivariate logistic regression and multiplicative interaction to assess associations among AGYW who reported the age of their primary sex partner from the last year.

RESULTS

The analysis included 1,958 AGYW (mean age = 19.9 years, SD = 0.1), 459 (23.4%) and 131 (6.7%) of whom reported age-disparate and intergenerational partnerships, respectively. AGYW in age-mixing partnerships accounted for 13% of all AGYW and were older, more likely to reside in urban areas, to be married or cohabitating with a partner, and to have engaged in riskier sexual behavior compared with AGYW in age-concordant partnerships (p < 0.05). HIV prevalence among AGYW in age-disparate and intergenerational partnerships was 6.1% and 11.9%, respectively, compared with 3.2% in age-concordant partnerships (p < 0.001). After adjusting for residence, age, education, employment, wealth quintile, and ever been married or cohabitated as married, AGYW in age-disparate and intergenerational partnerships had 1.9 (95% CI: 1.1-3.5) and 3.4 (95% CI: 1.6-7.2) greater odds of HIV, respectively, compared with AGYW in age-concordant partnerships. Among the 614 (31% of the study group) who endorsed inequitable gender norms, AGYW in age-disparate and intergenerational partnerships had 3.5 (95% CI: 1.1-11.8) and 6.4 (95% CI: 1.5-27.8) greater odds of HIV, respectively, compared with AGYW in age-concordant partnerships.

CONCLUSIONS

In this Malawi general population survey, age-mixing partnerships were associated with increased odds of HIV among AGYW. These findings highlight inequitable gender norms as a potential focus for HIV prevention and could inform interventions targeting structural, cultural, and social constraints of this key group.

Batswana Adolescents' Attitudes Toward Sex With Older Adults: Psychometric Properties of the Attitudes Toward Transactional Sex Scale

A programmatic series of studies developed and evaluated the Attitudes toward Transactional Sex Scale (ATTS) to measure adolescents' attitudes toward engaging in a sexual encounter initiated by an older adult offering desired objects such as cell phone, clothes, cash, or car rides in exchange for sex. Qualitative interviews informed the initial item generation followed by a series of studies assessing the psychometric properties of the measure. Study 1 evaluated the ATTS in a sample of 186 Batswana adolescents and assessed the factor structure, item-to-whole correlations, internal consistency, and convergent validity. In Study 2, the ATTS was administered to a cross-validation sample (N = 387). Confirmatory factor analysis, convergent validity, and internal consistency were consistent with the findings from the original sample. Discriminant validity was also assessed in Study 2. A subset of the sample (N = 119) completed the measure on two occasions and yielded satisfactory test-retest reliability. The resulting instrument appears to have sound psychometric properties and can be used to measure adolescents' attitudes toward accepting such adult sexual initiation that are implicated in the disproportionate burden of HIV among adolescents and young adults in sub-Saharan Africa. No existing measure with known psychometric properties has previously been available.

Protective factors for adolescent sexual risk behaviours and experiences linked to HIV infection in South Africa: a three-wave longitudinal analysis of caregiving, education, food security, and social protection

BACKGROUND

Structural interventions are endorsed to enhance biomedical and behavioural HIV prevention programmes for adolescents. Aiming to inform future interventions, we evaluated longitudinal associations between six protective factors that link closely to existing structural HIV prevention interventions, and five sexual risk behaviours for HIV transmission in a cohort of adolescents in South Africa.

METHODS

We used three rounds of data between 2014-2018 on 1046 adolescents living with HIV and 473 age-matched community peers in South Africa's Eastern Cape (Observations = 4402). We estimated sex-specific associations between six time-varying protective factors - number of social grants, education enrolment, days with enough food, caregiver supervision, positive caregiving, and adolescent-caregiver communication; and five HIV risk behaviours - multiple sexual partners, transactional sex, age-disparate sex, condomless sex, and sex on substances. HIV risk behaviours were analysed separately in multivariable random effects within-between logistic regression models that accounted for correlation of repeated observations on the same individual. We calculated prevalence ratios (PR), contrasting adjusted probabilities of HIV risk behaviours at 'No' and 'Yes' for education enrolment, and average and maximum values for the other five protective factors.

RESULTS

The sample mean age was 15.29 (SD: 3.23) years and 58% were girls. Among girls, within-individuals, increases from mean to maximum scores in positive caregiving were associated with lower probability of transactional sex (PR = 0.79; 95%CI = 0.67-0.91); in caregiver supervision were associated with lower probability of transactional sex (PR = 0.75; 95%CI = 0.66-0.84), and age-disparate sex (PR = 0.84; 95%CI = 0.73-0.95); in adolescent-caregiver communication were associated with higher probability of transactional sex (PR = 1.70; 95%CI = 1.08-2.32); and in days with enough food at home were associated with lower probability of multiple sexual partners (PR = 0.89; 95%CI = 0.81-0.97), and transactional sex (PR = 0.82; 95%CI = 0.72-0.92). Change from non-enrolment in education to enrolment was associated with lower probability of age-disparate sex (PR = 0.49; 95%CI = 0.26-0.73). Between-individuals, relative to mean caregiver supervision scores, maximum scores were associated with lower probability of multiple sexual partners (PR = 0.59; 95%CI = 0.46-0.72), condomless sex (PR = 0.80; 95%CI = 0.69-0.91), and sex on substances (PR = 0.42; 95%CI = 0.26-0.59); and relative to non-enrolment, education enrolment was associated with lower probability of condomless sex (PR = 0.59; 95%CI = 0.39-0.78). Among boys, within-individuals, increases from mean to maximum scores in positive caregiving were associated with lower probability of transactional sex (PR = 0.77; 95%CI = 0.59-0.96), and higher probability of condomless sex (PR = 1.26; 95%CI = 1.08-1.43); in caregiver supervision were associated with lower probability of multiple sexual partners (PR = 0.73; 95%CI = 0.64-0.82), transactional sex (PR = 0.63; 95%CI = 0.50-0.76), age-disparate sex (PR = 0.67; 95%CI = 0.49-0.85), and sex on substances (PR = 0.61; 95%CI = 0.45-0.78), and in days with enough food at home were associated with lower probability of transactional sex (PR = 0.91; 95%CI = 0.84-0.98).

CONCLUSION

Effective structural interventions to improve food security and education enrolment among adolescent girls, and positive and supervisory caregiving among adolescent girls and boys are likely to translate into crucial reductions in sexual risk behaviours linked to HIV transmission in this population.

Gender differences in HIV knowledge among adolescents and young people in low-and middle-income countries: a systematic review

Objectives

This review seeks to critically analyze studies assessing gender differences in HIV-related knowledge among adolescents and young people in low- and middle-income countries.

Methods

Using PRISMA guidelines and searching Pubmed and Scopus online databases, the search strategy combined search keywords with Boolean operators: (HIV OR AIDS) AND (knowledge) AND (gender) AND (adolescents). AC and EG conducted the search and independently reviewed all articles in Covidence software; conflicts were resolved by GC. Articles were included if they evaluated differences in HIV knowledge in at least two groups ages 10-24 and were implemented in a low or middle-income country.

Results

The search resulted in 4,901 articles, of which fifteen studies, implemented in 15 countries, met selection criteria. Twelve evaluated differences in HIV knowledge in school settings; three evaluated participants in clinic settings. Adolescent males consistently scored higher in composite knowledge scores, as well as knowledge of HIV transmission, prevention, attitudes and sexual decision-making.

Conclusion

We found gender-based discrepancies between knowledge, perception of risk and HIV prevalence among youth globally, with boys consistently scoring higher in HIV knowledge. However, there is significant evidence that social and cultural contexts render girls at high risk of HIV infection, and the gaps in girls' knowledge and boys' roles in HIV risk must be addressed urgently. Future research should consider interventions that facilitate discussion and HIV knowledge building across genders.

Transactional sex among women in Sub-Saharan Africa: A systematic review and meta-analysis

INTRODUCTION

Transactional sex is casual sex between two people to receive material incentives in exchange for sexual favors. Transactional sex is associated with negative consequences, which increase the risk of sexually transmitted diseases, including HIV/AIDS, unintended pregnancy, unsafe abortion, and physiological trauma. In Sub-Saharan Africa, several primary studies have been conducted in various countries to examine the prevalence and associated factors of transactional sex among women. These studies had great discrepancies and inconsistent results. Hence, this systematic review and meta-analysis aimed to synthesize the pooled prevalence of the practice of transactional sex among women and its associated factors in Sub-Saharan Africa.

METHOD

Data source: PubMed, Google Scholar, HINARI, the Cochrane Library, and grey literature were searched from March 6 to April 24, 2022, and included studies conducted from 2000 to 2022. The pooled prevalence of transactional sex and associated factors was estimated using Random Effect Model. Stata (version 16.0) was used to analyze the data. The I-squared statistic, a funnel plot, and Egger's test were used to check for heterogeneity and publication bias, respectively. A subgroup analysis was done based on the study years, source of data, sample sizes, and geographical location.

RESULTS

The pooled prevalence of transactional sex among women in Sub-Saharan Africa was 12.55% (9.59%-15.52%). Early sexual debut (OR = 2.58, 95% CI: 1.56, 4.27), substance abuse (OR = 4.62, 95% CI: 2.62, 8.08), history of sexual experience (OR = 4.87, 95% CI: 2.37, 10.02), physical violence abuse (OR = 6.70, 95% CI: 3.32, 13.53), orphanhood (OR = 2.10, 95% CI: 1.27, 3.47), and sexual violence abuse (OR = 3.76, 95% CI: 1.08, 13.05) were significantly associated with transactional sex.

CONCLUSION

The prevalence of transactional sex among women in sub-Saharan Africa was high. Alcohol consumption, substance abuse, early sex debuts, having a history of sexual experiences, physical violence, and sexual violence increased the practice of transactional sex.

The role of structural factors for preventing HIV risk practices among adolescents in South Africa: A three-wave analysis of caregiving, education, food security, and social protection

BACKGROUND

Structural interventions are endorsed to enhance biomedical and behavioural HIV prevention programmes for adolescents. Aiming to inform future interventions, we evaluated longitudinal associations between six structural factors and five HIV risk practices in a cohort of adolescents in South Africa.

METHODS

We used three rounds of data between 2014-2018 on 1046 adolescents living with HIV and 483 age-matched community peers in South Africa's Eastern Cape (Observations = 4402). We used multivariable random effects within-between logistic regression to estimate sex-specific associations between six time-varying structural factors - number of social grants, education enrolment, days with enough food, caregiver supervision, positive caregiving, and adolescent-caregiver communication - and five HIV risk practices - multiple sexual partners, transactional sex, age-disparate sex, condomless sex, and sex on substances. We calculated probability differences, contrasting predicted probabilities at average and maximum values of structural factors associated with multiple risk practices.

FINDINGS

The sample mean age was 15.29 (SD: 3.23) years and 58% were female. In females, compared to average, maximum positive caregiving scores were associated with lower probability of transactional sex (-1.06 percentage points [ppts], 95%CI=-1.60; -0.52ppts), and age-disparate sex (-0.73ppts; 95%CI=-1.26; -0.19ppts); maximum caregiver supervision scores were associated with lower probability of multiple sexual partners (-3.11ppts; 95%CI=-3.87; -2.35ppts) transactional sex (-1.07ppts, 95%CI=-1.42; -0.71ppts), age-disparate sex (-0.67ppts; 95%CI=-1.08; -0.25ppts), condomless sex (-3.96ppts; 95%CI=-5.65; -2.26ppts), and sex on substances (-0.93ppts; 95%CI=-1.50; -0.37ppts); and, seven days with enough food was associated with lower probability of multiple sexual partners (-1.18ppts, 95%CI=-2.06; -0.30ppts), and transactional sex (-0.91ppts; 95%CI=-1.41; -0.42ppts). Relative to non-enrolment, education enrolment was associated with lower probability of age-disparate sex (-3.18ppts; 95%CI=-5.35; -1.01ppts), and condomless sex (-11.32ppts; 95%CI=-19.15; -3.49ppts). In males, compared to average, maximum caregiver supervision scores were associated with lower probability of multiple sexual partners (-2.83ppts; 95%CI=-3.66; -2.00ppts), transactional sex (-0.90ppts; 95%CI=-1.20; -0.60ppts), age-disparate sex (-0.46ppts; 95%CI=-0.77; -0.15ppts), and sex on substances (-1.42ppts; 95%CI=-2.06; -0.78ppts). No other structural factors were associated with multiple risk practices.

INTERPRETATION

Structural interventions to improve food security and education enrolment among adolescent girls, and positive and supervisory caregiving among adolescent girls and boys are likely to translate into crucial reductions in HIV risk.

Male partner age, viral load, and HIV infection in adolescent girls and young women: evidence from eight sub-Saharan African countries

OBJECTIVE

We aimed to elucidate the role of partnerships with older men in the HIV epidemic among adolescent girls and young women (AGYW) aged 15-24 years in sub-Saharan Africa.

DESIGN

Analysis of Population-based HIV Impact Assessments in Eswatini, Lesotho, Malawi, Namibia, Tanzania, Uganda, Zambia, and Zimbabwe.

METHODS

We examined associations between reported partner age and recent HIV infection among AGYW, incorporating male population-level HIV characteristics by age-band. Recent HIV infection was defined using the LAg avidity assay algorithm. Viremia was defined as a viral load of more than 1000 copies/ml, regardless of serostatus. Logistic regression compared recent infection in AGYW with older male partners to those reporting younger partners. Dyadic analysis examined cohabitating male partner age, HIV status, and viremia to assess associations with AGYW infection.

RESULTS

Among 17 813 AGYW, increasing partner age was associated with higher odds of recent infection, peaking for partners aged 35-44 (adjusted odds ratio = 8.94, 95% confidence interval: 2.63-30.37) compared with partners aged 15-24. Population-level viremia was highest in this male age-band. Dyadic analyses of 5432 partnerships confirmed the association between partner age-band and prevalent HIV infection (male spousal age 35-44-adjusted odds ratio = 3.82, 95% confidence interval: 2.17-6.75). Most new infections were in AGYW with partners aged 25-34, as most AGYW had partners in this age-band.

CONCLUSION

These results provide evidence that men aged 25-34 drive most AGYW infections, but partners over 9 years older than AGYW in the 35-44 age-band confer greater risk. Population-level infectiousness and male age group should be incorporated into identifying high-risk typologies in AGYW.

Characterization of HIV-1 Transmission Clusters Inferred from the Brazilian Nationwide Genotyping Service Database

The study of HIV-1 transmission networks inferred from viral genetic data can be used to clarify important factors about the dynamics of HIV-1 transmission, such as network growth rate and demographic composition. In Brazil, HIV transmission has been stable since the early 2000s and the study of transmission clusters can provide valuable data to understand the drivers of virus spread. In this work, we analyzed a nation-wide database of approximately 53,000 HIV-1 nucleotide pol sequences sampled from genotyped patients from 2008-2017. Phylogenetic trees were reconstructed for the HIV-1 subtypes B, C and F1 in Brazil and transmission clusters were inferred by applying genetic distances thresholds of 1.5%, 3.0% and 4.5%, as well as high (>0.9) cluster statistical support. An odds ratio test revealed that young men (15-24 years) and individuals with more years of education presented higher odds to cluster. The assortativity coefficient revealed that individuals with similar demographic features tended to cluster together, with emphasis on features, such as place of residence and age. We also observed that assortativity weakens as the genetic distance threshold increases. Our results indicate that the phylogenetic clusters identified here are likely representative of the contact networks that shape HIV transmission, and this is a valuable tool even in sites with low sampling density, such as Brazil.

Estimating age specific prevalence and force of infection in Zimbabwe using combined cross-sectional surveys from 2005 to 2015

Objective

Age structured sexual mixing patterns have been noted to be associated with HIV prevalence and force of infection. Therefore, this study aimed to estimate the age dependent HIV force of infection using survey cross-sectional data from Zimbabwe.

Methods

We fit generalized additive models namely; linear, semi-parametric, non-parametric and non-proportional hazards models. Using the 2005-06, 2010-11 and 2015 Zimbabwe Demographic Health Surveys data. The Akaike Information Criteria was used to select the best model. The best model was then used to estimate the age dependent HIV prevalence and force-of-infection.

Results

Based on birth year cohort-specific prevalence, the female HIV prevalence reaches the highest peak at around 29 years of age, then declines thereafter. Males have a lower cohort specific prevalence between 15 and 30 years than females. Male cohort-specific prevalence slightly decreases between the ages of 33 and 39, then peaks around the age of 40. The cohort-specific FOI is greater in females than in males throughout all age categories. In addition, the cohort-specific HIV FOI peaked at ages 22 and 40 for females and males, respectively. The observed 18-year age difference between the HIV FOI peaks of males and females.

Conclusion

Our model was appealing because we did not assume that the FOI is stationary over time; however, we used serological survey data to distinguish the FOI's age-and-time effect. The cohort-specific FOI peaked 18 years earlier in females than males, indicative of age-mixing patterns. We recommend interventions that target younger females so as to reduce HIV transmission rates.

Effectiveness of Cash Transfer Delivered Along With Combination HIV Prevention Interventions in Reducing the Risky Sexual Behavior of Adolescent Girls and Young Women in Tanzania: Cluster Randomized Controlled Trial

BACKGROUND

Poverty and social inequality exacerbate HIV risk among adolescent girls and young women (AGYW) in sub-Saharan Africa. Cash transfers can influence the structural determinants of health, thereby reducing HIV risk.

OBJECTIVE

This study assessed the effectiveness of cash transfer delivered along with combination HIV prevention (CHP) interventions in reducing the risky sexual behavior of AGYW in Tanzania. The incidence of herpes simplex virus type 2 (HSV-2) infection was used as a proxy for sexual risk behavior.

METHODS

A cluster randomized controlled trial was conducted in 15 matched pairs of communities (1:1 intervention to control) across 3 strata (urban, rural high-risk, and rural low-risk populations) of the Shinyanga Region, Tanzania. The target population was out-of-school AGYW aged 15-23 years who had completed 10-hour sessions of social and behavior change communication. Eligible communities were randomly assigned to receive CHP along with cash transfer quarterly (intervention group) or solely CHP interventions (control group) with no masking. Study recruitment and baseline survey were conducted between October 30, 2017 and December 1, 2017. Participants completed an audio computer-assisted self-interview, HIV counselling and testing, and HSV-2 testing at baseline and during follow-up visits at 6, 12, and 18 months after the baseline survey. A Cox proportional hazards model with random effects specified at the level of clusters (shared frailty) adjusted for matching pairs and other baseline imbalances was fitted to assess the effects of cash transfer on the incidence of HSV-2 infection (primary outcome). Secondary outcomes included HIV prevalence at follow-up, self-reported intergenerational sex, and self-reported compensated sex. All secondary outcomes were measured at each study visit.

RESULTS

Of the 3026 AGYW enrolled in the trial (1482 in the intervention and 1544 in the control), 2720 AGYW (1373 in the intervention and 1347 in the control) were included in the final analysis. Overall, HSV-2 incidence was not significantly different at all follow-up points between the study arms in the adjusted analysis (hazard ratio 0.96, 95% CI 0.67-1.38; P=.83). However, HSV-2 incidence was significantly lower in the rural low-risk populations who received the cash transfer intervention (hazard ratio 0.45, 95% CI 0.29-0.71; P=.001), adjusted for potential confounders.

CONCLUSIONS

Although this trial showed no significant impact of the cash transfer intervention on HSV-2 incidence among AGYW overall, the intervention significantly reduced HSV-2 incidence among AGYW in rural low-risk communities. Factors such as lesser poverty and more asset ownership in urban and rural high-risk communities may have undermined the impact of cash transfer.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03597243; https://clinicaltrials.gov/show/NCT03597243.

Time to First Sexual Experience and Its Determinants among Female Youths in Ethiopia: Survival Analysis Based on EDHS 2016

Background

The first sexual experience is the most significant event in a woman's life. Early sexual experience has short- and long-term health and behavioral risks. Studying the estimated time for a female to have her first sexual debut is important to reduce its health, demographic, and socioeconomic consequences. Thus, this study is aimed at assessing the time to first sexual experience and its determinants in Ethiopia.

Methods

A survival analysis of time to first sexual experience was conducted among 6143 weighted study subjects. The data were extracted from EDHS 2016 using STATA version 16 software. A Kaplan-Meier survival curve was computed to estimate the time of first sexual experience. A log-rank test was used to compare the difference in survival curves. The Cox proportional hazard regression model was used to identify significant predictors. On multivariable analysis, variables having a p value of ≤ 0.05 are considered statically significant.

Results

The overall median survival time was 16 years. The significant determinants of time to first sexual experience are educational level (no education (AHR = 2.72, 95% CI: 2.16, 3.39), primary education (AHR = 2.17, 95% CI: 1.79, 2.63), and secondary education (AHR = 1.47, 95% CI: 1.21, 1.77)) and wealth index (poor (AHR = 1.15, 95% CI: 1.00, 1.32)).

Conclusion

About 50% of female youths have a sexual experience for the first time before their 16th birthday. The timing of the first sexual experience in Ethiopia was mainly influenced by educational level and wealth index. Universal access to education and poverty reduction should be the area of concern.

Acceptability and feasibility of leveraging community-based HIV counselling and testing platforms for same-day oral PrEP initiation among adolescent girls and young women in Eastern Cape, South Africa

INTRODUCTION

Community-based delivery of HIV pre-exposure prophylaxis (PrEP) to South African adolescent girls and young women's (AGYW) could increase access but needs evaluation. We integrated PrEP services via home-based services and pop-up tents into existing community-based HIV testing services (CB-HTS) in Eastern Cape Province, South Africa.

METHODS

After accessing CB-HTS via a "pop-up" tent or home-based services, HIV-negative AGYW aged 16-25 years were invited to complete a baseline questionnaire and referred for PrEP services at a community-based PrEP site co-located with pop-up HTS tents. A 30-day supply of PrEP was dispensed. PrEP uptake, time-to-initiation, cohort characteristics and first medication refill within 90 days were measured using descriptive statistics.

RESULTS

Of the 1164 AGYW who tested for HIV, 825 (74.3%) completed a questionnaire and 806 (97.7%) were referred for community-based PrEP. Of those, 624 (77.4%) presented for PrEP (482/483 [99.8%] from pop-up HTS and 142/323 [44.0%] from home-based HTS), of which 603 (96.6%) initiated PrEP. Of those initiating PrEP following home-based HTS, 59.1% initiated within 0-3 days, 25.6% within 4-14 days and 15.3% took ≥15 days to initiate; 100% of AGYW who used pop-up HTS initiated PrEP the same day. Among AGWY initiating PrEP, 37.5% had a detectable sexually transmitted infection (STI). Although AGYW reported a low self-perception of HIV risk, post-hoc application of HIV risk assessment measures to available data classified most study participants as high risk for HIV acquisition. Cumulatively, 329 (54.6%) AGYW presented for a first medication refill within 90 days of accepting their first bottle of PrEP.

CONCLUSIONS

Leveraging CB-HTS platforms to provide same-day PrEP initiation and refill services was acceptable to AGYW. A higher proportion of AGYW initiated PrEP when co-located with CB-HTS sites compared to those referred following home-based HTS, suggesting that proximity of CB-HTS and PrEP services facilitates PrEP uptake among AGYW. The high prevalence of STIs among those initiating PrEP necessitates the integration of STI and HIV prevention programs for AGYW. Eligibility for PrEP initiation should not be required among AHYW in high HIV burden communities. Community-based service delivery will be crucial to maintaining access to PrEP services during the COVID-19 pandemic and future health and humanitarian emergencies.

Incident HIV Infection Among Young Men Associated With Female Sexual Partner Types Identified Through Latent Class Analysis, Rakai, Uganda

BACKGROUND

Sexual partner characteristics are important determinants of HIV acquisition, but little is known about partner types of young men in sub-Saharan Africa.

METHODS

Sexually active men aged 15-24 years from 5 rounds (2005-2013) of the Rakai Community Cohort Study in Uganda reported characteristics of up to 4 past-year female partners. Partner types were identified using latent class analysis. HIV incidence rates (IRs) were calculated by partner-type combinations, and individual-level risk adjusted IR ratios (aIRRs) relative to the lowest incidence type were estimated using the Poisson regression with generalized estimating equations.

RESULTS

Young men (N = 1771) reported 4539 past-year female sexual partners. Three partner types were identified: type A: noncohabiting, student, medium duration partnerships; type B: cohabiting, nonstudent, longer duration partnerships; and type C: noncohabiting, nonstudent shorter duration partnerships. Type C partners engaged in the most HIV-related risk behaviors. Many men (29%) had more than 1 partner type/round. IR overall was 9.8/1000 person-years [95% confidence interval (CI): 4.7 to 20.6]. IR was 4.0 (95% CI: 1.2 to 12.7) for men with type A partners alone (41% of men). Relative to them, IR for those with type B partners alone (25%) was not significantly different. Men with type C partners alone (5%) had higher risk (aIRR = 3.2; 95% CI: 1.0 to 9.9), as did men with >1 partner type, including men with both type A and type B partners (12%; aIRR = 6.3; 95% CI: 2.5 to 15.9) and men with type C and other partner types (17%; aIRR = 4.3; 95% CI: 1.7 to 10.8).

CONCLUSIONS

Partner-type combination was strongly associated with HIV incidence; type C partners and having more than 1 partner type were the riskiest patterns.

Determining HIV risk for Adolescent Girls and Young Women (AGYW) in relationships with "Blessers" and age-disparate partners: a cross-sectional survey in four districts in South Africa

BACKGROUND

HIV incidence among adolescent girls and young women (AGYW) remains high, with their male partners a prominent factor in sustaining these elevated rates. Partnership characteristics remain important metrics for determining HIV risk, with evidence indicating that AGYW engaged in transactional and age-disparate relationships face greater HIV exposure. This study examines the risk posed to AGYW in a relationship with a "Blesser", defined as male who provides his female partner with their material needs or desires in exchange for a sexual relationship, an age-disparate (5 or more years older) partner, and the potential compounded risk of being a relationship with a partner or partners who are considered both a "Blesser" and age-disparate.

METHODS

A cross -sectional household based representative sample of AGYW (aged between 12-24 years) were enrolled in the study (n = 18 926) from the districts of City of Johannesburg and Ekurhuleni in the Gauteng province and the Districts of eThekwini and uMgungundlovu in the province of KwaZulu-Natal (KZN) in South Africa between March 13, 2017 to June 22, 2018. Participants completed a structured questionnaire and provided finger-prick blood samples for laboratory measurements. Our analysis used descriptive statistics and multiple binary logistic regressions accounting for survey weights, clustering and stratification.

FINDINGS

The median age of the sample was 21 years old (Interquartile range: 19-23) and nearly three quarters (73.7%) were currently attending school. Whilst all relationships exposed AGYW to potential HIV risk, multiple binary logistic regression analysis revealed that AGYW in a relationship with both a Blesser and an age-disparate partner were more likely to be HIV positive (AOR: 3.12, 95% CI: 1.76-5.53, p < 0.001), diagnosed with an STI (AOR: 4.60, 95% CI: 2.99-7.08, p < 0.001), had 2 or more sexual partners in the previous 12 months (AOR: 6.37, 95% CI: 3.85-10.54, p < 0.001), engaged in sexual activity at age 15 or younger (AOR: 3.67, 95% CI: 2.36-5.69, p < 0.001) and more likely to have ever been pregnant (AOR: 2.60, 95% CI: 1.24-5.45, p < 0.05) than those not in a relationship with either a Blesser or age-disparate partner.

CONCLUSION

Different relationships present different HIV risk to AGYW. AGYW who had engaged in relationships with both a Blesser and an age-disparate partner were at greater HIV risk when examined against these relationships independent of one another. The data reveals the compounded HIV risk of being in both a transactional and age-disparate relationship.

Association of HIV Intervention Uptake With HIV Prevalence in Adolescent Girls and Young Women in South Africa

IMPORTANCE

In South Africa, adolescent girls and young women aged 15 to 24 years are among the most high-risk groups for acquiring HIV. Progress in reducing HIV incidence in this population has been slow.

OBJECTIVE

To describe HIV prevalence and HIV risk behaviors among a sample of adolescent girls and young women and to model the association between exposure to multiple or layered interventions and key HIV biological and behavioral outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional survey was conducted between March 13, 2017, and June 22, 2018, in 2 districts in Gauteng province and in 2 districts in KwaZulu-Natal province in South Africa. A stratified cluster random sampling method was used. Participants included adolescent girls and young women aged 12 to 24 years who lived in each sampled household. Overall, 10 384 participants were enrolled in Gauteng province and 7912 in KwaZulu-Natal province. One parent or caregiver was interviewed in each household. Data analysis was performed from March 12, 2021, to March 1, 2022.

EXPOSURES

DREAMS (Determined, Resilient, Empowered, AIDS-free, Mentored, and Safe)-like interventions.

MAIN OUTCOMES AND MEASURES

The primary outcome was HIV prevalence. HIV status was obtained from laboratory-based testing of peripheral blood samples. Secondary outcomes included HIV testing and antiretroviral therapy uptake as well as numerous HIV risk variables that the DREAMS program sought to improve, such as pregnancy, sexually transmitted infection, intimate partner violence, and age-disparate sex.

RESULTS

The final sample included 18 296 adolescent girls and young women (median [IQR] age, 19 [15-21] years) in 10 642 households. Approximately half of participants (49.9%; n = 8414) reported engaging in sexual activity, and 48.1% (n = 3946) reported condom use at the most recent sexual encounter. KwaZulu-Natal province had a higher HIV prevalence than Gauteng province (15.1% vs 7.8%; P < .001). Approximately one-fifth of participants (17.6%; n = 3291) were not exposed to any interventions, whereas 43.7% (n = 8144) were exposed to 3 or more interventions. There was no association between exposure to DREAMS-like interventions and HIV status. Adolescent girls and young women who accessed 3 or more interventions were more likely to have undergone HIV testing (adjusted odds ratio, 2.39; 95% CI, 2.11-2.71; P < .001) and to have used condoms consistently in the previous 12 months (adjusted odds ratio, 1.68; 95% CI, 1.33-2.12; P < .001) than those who were not exposed to any interventions.

CONCLUSIONS AND RELEVANCE

Results of this study suggest that self-reported exposures to multiple or layered DREAMS-like interventions were associated with favorable behavioral outcomes. The beneficial aspects of layering HIV interventions warrant further research to support the sexual and reproductive health of adolescent girls and young women.

Examining Why Age-Disparate Relationships Influence Unsafe Sex Postpartum Among South African Women: Relationship Control and Physical Partner Violence as Explanatory Mechanisms

HIV incidence rates in South Africa are extremely high, particularly postpartum. However, there is limited knowledge of women's HIV risk behavior postpartum. Women in age-disparate relationships may be less able to negotiate safe sex postpartum than women whose partners are similar ages because they have less relationship power. The study's purpose is to test whether being in an age-disparate relationship predicts postpartum unsafe sex and to explore relationship control and intimate partner violence (IPV) as explanatory mechanisms. Data are obtained from 516 HIV-negative participants who completed a survey during pregnancy and at 14 weeks postpartum as part of a longitudinal study in Durban. Age variables, relationship control, and IPV during pregnancy were included in a multivariate model predicting unsafe sex postpartum. We also assessed whether the hypothesized mediators explained the association between being in an age-disparate relationship and unsafe sex postpartum by using indirect effect analysis with bootstrapping. Women's mean age was 24.34 years (range = 18.03-45.36); the mean difference in ages in relationships was 3.19 years (range = -6.1 to 30.1). More than a quarter reported unsafe sex postpartum (27%). Age-disparate relationship, lower relationship control, and higher IPV were each longitudinally associated with unsafe sex. Relationship control, but not IPV, mediated the association between age-disparate relationship and unsafe sex (indirect effect [B] = 0.01, 95% confidence interval [CI] = [0.0002, 0.0283]). Age disparity, relationship control, and IPV all contributed to unsafe sex postpartum. Interventions that reduce the formation of age-disparate relationships and increase women's relationship power in pregnancy are needed to reduce women's HIV risk in the postpartum period.

Psychosocial Support, Sexual Health, and HIV Risk among Older Men Who Have Sex with Younger Men

This study examines the extent to which older males are willing to offer psychosocial and sexual health promoting support to their younger male partners, as well as the individual and relationship-level factors associated with this willingness to provide support. In total, 324 men over the age of 45, who currently or previously had younger male sexual partners, completed an anonymous online survey. Results show that participants were most willing to provide emotional support to their younger male partners, followed by health-related encouragement, HIV/STI testing support, and financial support. Of note, HIV positive status and being in a "main partnership" were associated with greater willingness to provide financial support. These results suggest that older men are willing to provide psychosocial and health promotive support to younger male partners, which could be leveraged in targeted interventions to reduce HIV transmission.

The determinants and impacts of age-disparate relationships on women in Zimbabwe: A life course perspective

Age-disparate relationships (ADR) with older men have been studied mostly in the context of HIV and found to be associated with increased HIV prevalence among young women in sub-Saharan Africa. Less is known about the impact of ADR on the broader life course of women. The objectives of this study are to identify the factors associated with being in ADR and estimate the association between ADR and a set of life outcomes in Manicaland, Zimbabwe. We used data from a general population open-cohort survey from 1998 to 2013 in Manicaland. We applied binary logistic regression models to estimate the odds ratios for association between socio-demographic determinants and ADR and multinomial logistic regression models to estimate the association between ADR and women's life outcomes. We found that women with less education, younger age at first sex and first marriage were more likely to be in ADR, and women in ADR have male partners with less education and less skilled employment. In terms of life and relationship outcomes, women in ADR had mostly negative life outcomes compared to women not in ADR. Future policies and research on ADR in women should reflect these complexities and study a wider range of life outcomes, beyond the commonly studied narrower topics such as HIV.

Prevalence and factors associated with HIV-1 drug resistance mutations in treatment-experienced patients in Nairobi, Kenya: A cross-sectional study

ABSTRACT

An estimated 1.5 million Kenyans are HIV-seropositive, with 1.1 million on antiretroviral therapy (ART), with the majority of them unaware of their drug resistance status. In this study, we assessed the prevalence of drug resistance to nucleoside reverse transcriptase inhibitors (NRTIs), nucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors, and the variables associated with drug resistance in patients failing treatment in Nairobi, Kenya.This cross-sectional study utilized 128 HIV-positive plasma samples obtained from patients enrolled for routine viral monitoring in Nairobi clinics between 2015 and 2017. The primary outcome was human immunodeficiency virus type 1 (HIV-1) drug resistance mutation counts determined by Sanger sequencing of the polymerase (pol) gene followed by interpretation using Stanford's HIV Drug Resistance Database. Poisson regression was used to determine the effects of sex, viral load, age, HIV-subtype, treatment duration, and ART-regimen on the primary outcome.HIV-1 drug resistance mutations were found in 82.3% of the subjects, with 15.3% of subjects having triple-class ART resistance and 45.2% having dual-class resistance. NRTI primary mutations M184 V/I and K65R/E/N were found in 28.8% and 8.9% of subjects respectively, while NNRTI primary mutations K103N/S, G190A, and Y181C were found in 21.0%, 14.6%, and 10.9% of subjects. We found statistically significant evidence (P = .013) that the association between treatment duration and drug resistance mutations differed by sex. An increase of one natural-log transformed viral load unit was associated with 11% increase in drug resistance mutation counts (incidence rate ratio [IRR] 1.11; 95% CI 1.06-1.16; P < .001) after adjusting for age, HIV-1 subtype, and the sex-treatment duration interaction. Subjects who had been on treatment for 31 to 60 months had 63% higher resistance mutation counts (IRR 1.63; 95% CI 1.12-2.43; P = .013) compared to the reference group (<30 months). Similarly, patients on ART for 61 to 90 months were associated with 133% higher mutation counts than the reference group (IRR 2.33; 95% CI 1.59-3.49; P < .001). HIV-1 subtype, age, or ART-regimen were not associated with resistance mutation counts.Drug resistance mutations were found in alarmingly high numbers, and they were associated with viral load and treatment time. This finding emphasizes the importance of targeted resistance monitoring as a tool for addressing the problem.

"You are not alone": a qualitative study to explore barriers to ART initiation and implications for a proposed community-based youth treatment club among young adults newly diagnosed with HIV in South Africa

In South Africa, despite universal antiretroviral therapy (ART) availability, 60% of persons living with HIV (PLWH) ages 15-24 are not on treatment. This qualitative study aimed to identify barriers to ART initiation and the implications for a proposed community-based Youth Treatment Club to improve ART initiation for young PLWH in limited-resource, high HIV-prevalence communities in Cape Town, South Africa. Recruiting participants at community testing sites from 2018 to 2019, we conducted semi-structured interviews, informed by Social Action Theory (SAT), with 20 young adults, ages 18- to 24-years-old, newly diagnosed with HIV, along with 10 healthcare providers. Through systematic qualitative analysis, we found that young PLWH face barriers to treatment initiation in three SAT domains: (1) stigmatizing social norms (social regulation processes); (2) challenges coping with a new diagnosis (self-regulation processes); and (3) anticipated stigma in the clinic environment (contextual factors). Participants shared that a proposed community-based Youth Treatment Club for newly diagnosed youth would be an acceptable strategy to promote ART initiation. They emphasized that it should include supportive peers, trained facilitator support for counseling and education, and a youth-friendly environment.

Reductions in HIV incidence are likely to increase the importance of key population programmes for HIV control in sub-Saharan Africa

INTRODUCTION

An efficient HIV response requires that resources be focussed on effective interventions for those most at risk of acquiring and transmitting infection. As HIV epidemics evolve the distribution of HIV across key and other populations will change. Here, the epidemiological concepts underpinning these changes are described and the importance of appropriate allocation of effective interventions is discussed.

DISCUSSION

In many sub-Saharan African countries HIV epidemics have been categorized as "generalized," and HIV testing, treatment and prevention interventions have focussed on the "general" population. As HIV epidemics are better controlled the relative importance of "key" populations will increase, dominating the ongoing burden of disease and providing the potential for repeated outbreaks of HIV if interventions are relaxed. The basic reproductive number (R0 ) describes the potential for an infectious disease to spread at the boundary of invasion or elimination, whereas the effective reproduction number (Rt ) describes the current potential for spread. Heterogeneity in risk means that while Rt is temporarily below one and prevalence declining, the R0 can remain above one, preventing eventual elimination. Patterns of HIV acquisition are often used to guide interventions but inadequately capture the transmission dynamics of the virus and the most efficient approach to controlling HIV. Risks for HIV acquisition are not identical to risks for HIV transmission and will change depending on the epidemiological context. In addition to the challenges in measuring HIV transmission dynamics, there is a tension between using epidemiology to drive the HIV response and the social and political realities constraining how programmes and providers can practically and appropriately focus on key populations and maintain political support. In addition to being well focussed, interventions need to be effective and cost-effective, which requires a better understanding of packages of interventions rather than specific tools.

CONCLUSIONS

Continued control of HIV will increasingly rely on resources, programmes and interventions supporting key populations. Current epidemiological and programmatic approaches for key populations in sub-Saharan Africa are insufficient with a need for an improved understanding of local epidemiology and the effectiveness of interventions.

Evaluating distributional regression strategies for modelling self-reported sexual age-mixing

The age dynamics of sexual partnership formation determine patterns of sexually transmitted disease transmission and have long been a focus of researchers studying human immunodeficiency virus. Data on self-reported sexual partner age distributions are available from a variety of sources. We sought to explore statistical models that accurately predict the distribution of sexual partner ages over age and sex. We identified which probability distributions and outcome specifications best captured variation in partner age and quantified the benefits of modelling these data using distributional regression. We found that distributional regression with a sinh-arcsinh distribution replicated observed partner age distributions most accurately across three geographically diverse data sets. This framework can be extended with well-known hierarchical modelling tools and can help improve estimates of sexual age-mixing dynamics.

Factors associated with age-disparate sexual partnerships among males and females in South Africa: a multinomial analysis of the 2012 national population-based household survey data

BACKGROUND

In South Africa, age-disparate to sexual relationships where the age difference between partners is 5 years or greater is an important contributor to the spread of HIV. However, little is known about the predictors of age-disparate sexual relationships. This study investigates factors associated with age-disparate sexual relationships among males and females in South Africa.

METHODS

This analysis used the 2012 nationally representative population-based household survey conducted using multi-stage stratified cluster sampling design. Multivariate multinomial stepwise logistic regression models were used to determine factors associated with age-disparate sexual relationships.

RESULTS

Of 15,717 participants, who responded to the question on age-disparate sexual relationships, 62% males versus 58.5% females had partners within 5 years older or younger, 34.7% of males versus 2.7% of females had partners at least 5 years younger and 3.3% of males versus 38.8% of females had partners at least 5 years older. Among both males and females predictors of age-disparate sexual relationships were education, employment, socioeconomic status, locality type, age at sexual debut, condom use at last sexual act and HIV status while race was also an additional predictor for among females. Including unprotected sex and risk of HIV infection among adolescent girls and young women with sexual partners 5 years older their age.

CONCLUSIONS

This study suggest that there is a need for reprioritizing the combination of behavioural and structural interventions to address risky sexual behaviours, unprotected sex, poverty, limited education and gender inequitable norms related to age-disparate sexual relationships and HIV.

Timing, number, and type of sexual partners associated with risk of oropharyngeal cancer

BACKGROUND

Case-control studies from the early 2000s demonstrated that human papillomavirus-related oropharyngeal cancer (HPV-OPC) is a distinct entity associated with number of oral sex partners. Using contemporary data, we investigated novel risk factors (sexual debut behaviors, exposure intensity, and relationship dynamics) and serological markers on odds of HPV-OPC.

METHODS

HPV-OPC patients and frequency-matched controls were enrolled in a multicenter study from 2013 to 2018. Participants completed a behavioral survey. Characteristics were compared using a chi-square test for categorical variables and a t test for continuous variables. Adjusted odds ratios (aOR) were calculated using logistic regression.

RESULTS

A total of 163 HPV-OPC patients and 345 controls were included. Lifetime number of oral sex partners was associated with significantly increased odds of HPV-OPC (>10 partners: odds ratio [OR], 4.3 [95% CI, 2.8-6.7]). After adjustment for number of oral sex partners and smoking, younger age at first oral sex (<18 vs >20 years: aOR, 1.8 [95% CI, 1.1-3.2]) and oral sex intensity (>5 sex-years: aOR, 2.8 [95% CI, 1.1-7.5]) remained associated with significantly increased odds of HPV-OPC. Type of sexual partner such as older partners when a case was younger (OR, 1.7 [95% CI, 1.1-2.6]) or having a partner who had extramarital sex (OR, 1.6 [95% CI, 1.1-2.4]) was associated with HPV-OPC. Seropositivity for antibodies to HPV16 E6 (OR, 286 [95% CI, 122-670]) and any HPV16 E protein (E1, E2, E6, E7; OR, 163 [95% CI, 70-378]) was associated with increased odds of HPV-OPC.

CONCLUSION

Number of oral sex partners remains a strong risk factor for HPV-OPC; however, timing and intensity of oral sex are novel independent risk factors. These behaviors suggest additional nuances of how and why some individuals develop HPV-OPC.

Characteristics and outcomes of adolescents living with perinatally acquired HIV within Southern Africa

BACKGROUND

Using data from 15 International epidemiology Databases to Evaluate AIDS in Southern Africa sites, we compared the characteristics and outcomes of adolescents living with perinatally acquired HIV (ALPH).

METHODS

We included ALPH entering care aged less than 13 years with at least one HIV care visit during adolescence (10-19 years). We compared the characteristics and cross-sectional outcomes: transfer out, loss to follow-up (no visit in the 12 months prior to database closure), mortality, and retention between those who entered care aged less than 10 vs. aged 10-13 years; and explored predictors of mortality after age 13 years using Cox Proportional Hazards models.

RESULTS

Overall, 16 229 (50% female) ALPH who entered HIV care aged less than 10 years and 8897 (54% female) aged 10-13 years were included and followed for 152 574 person-years. During follow-up, 94.1% initiated antiretroviral therapy, with those who entered care aged less than 10 more likely to have initiated antiretroviral therapy [97.9%, 95% confidence interval (CI) 97.6; 98.1%] than those who presented aged 10-13 years (87.3%, 95% CI 86.6; 88.0%). At the end of follow-up, 3% had died (entered care aged <10 vs. 10-13 years; 1.4 vs. 5.1%), 22% were loss to follow-up (16.2 vs. 33.4%), and 59% (66.4 vs. 45.4%) were retained. There was no difference in the risk of dying after the age of 13 years between adolescents entering care aged less than 10 vs. 10-13 years (adjusted hazard ratio 0.72; 95% CI 0.36; 1.42).

CONCLUSION

Retention outcomes for ALPH progressively worsened with increasing age, with these outcomes substantially worse among adolescents entering HIV care aged 10-13 vs. less than 10 years.

Risk of HIV infection among adolescent girls and young women in age-disparate relationships in sub-Saharan Africa

OBJECTIVE

To determine the association between age-disparate relationships and risk of HIV infection among adolescent girls and young women (AGYW) aged 15-24 years.

DESIGN

Systematic review and meta-analysis of published studies until January 5, 2020 in sub Saharan Africa (SSA).

METHODS

We searched several electronic databases, grey literature, and hand searched reference list of included studies to identify eligible studies for data abstraction. We assessed the quality of included studies using Newcastle-Ottawa Scale for nonrandomized studies. The DerSimonian-Laird random effects model was used to pool the overall results using risk ratios (RR), presented in a forest plot with 95% confidence interval (CI) and predictive interval. Heterogeneity was assessed with Cochrane's Q-test and quantified with I values. Publication bias was checked with funnel plots and Egger's test.

RESULTS

We included 24 studies with an overall sample size of 33 390. Data show that age-disparate relationships were significantly associated with unprotected sexual intercourse (pooled RR, 1.57; 95% CI, 1.34-1.83; 95% predictive interval, 1.22-2.02), and higher risk for HIV infection (pooled RR, 1.39; 95 CI, 1.21-1.60; 95% predictive interval, 0.80-2.42). Studies included in pooling risk of unprotected sexual intercourse were largely homogeneous (I-value= 0.0, P = 0.79) whereas those for HIV infection were heterogeneous (I- value = 89.0%, P < 0.01). We found no publication bias and no study influenced the meta-analytic results.

CONCLUSION

Age-disparate relationships among AGYW are associated with increased risk of unprotected sexual intercourse and HIV infection in SSA. HIV prevention interventions should target this sub-population.

Bayesian method for inferring the impact of geographical distance on intensity of communication

Spatially-embedded networks represent a large class of real-world networks of great scientific and societal interest. For example, transportation networks (such as railways), communication networks (such as Internet routers), and biological networks (such as fungal foraging networks) are all spatially embedded. Both the density of interactions (presence of edges) and intensity of interactions (edge weights) are typically found to decrease as a function of spatial separation of nodes in these networks. Communication and mobility of groups of individuals have also been shown to decline with their spatial separation, and the so-called gravity model postulates that this decline takes the form of a power-law holding at all distances. There is however some evidence that the rate of decline might change as the distance increases beyond a certain value, called a change point, but there have been few statistically principled methods for determining the existence and location of change points or assessing the change in intensity of interactions associated with them. We introduce such a method within the Bayesian paradigm and apply it to anonymized mobile call detail records (CDRs). Our results are potentially useful in settings where understanding social and spatial mixing of people is important, such as in the design of cluster randomized trials for studying interventions for infectious diseases, but we also anticipate the method to be useful for investigating more generally how distance may affect tie strengths in general in spatially embedded networks.

Urban-rural disparity in sociodemographic characteristics and sexual behaviors of HIV-positive adolescent girls and young women and their perspectives on their male sexual partners: A cross-sectional study in Zimbabwe

We conducted a cross sectional survey in Zimbabwe to describe urban-rural disparity in socio-demographic characteristics and sexual behaviors of HIV-positive adolescent girls and young women (AGYW) and their male sexual partners. Between September and November 2016, we interviewed 360 sexually active HIV positive AGYW, aged 15––24 years attending ART and PMTCT clinics in urban and rural health facilities in Harare and Mazowe district respectively. HIV positive AGYW in rural areas as compared to those in urban areas were older, less educated, more frequently married or cohabiting, had lower number of male sexual partners in their lifetime and in the last 12 months preceding the survey. They were mostly heterosexually infected, more likely to disclose their status to a family member and to be more adherent to ART (OR = 2.5–95% CI = 1.1–5.5). Most recent male sexual partners of HIV positive AGYW in urban areas as compared to those from rural areas were mainly current or former boyfriends, single, more educated, less likely to have a child with them and to engage in couple voluntary counseling and testing (CVCT). They were more likely to patronize dancing and drinking venues and involved in transactional sex (OR = 2.2–95% CI: 1.2–4). They were also more likely to be circumcised (OR = 2.3–95% CI: 1.3–4.1) and to use condom more consistently in the last 12 months preceding the survey. Our study findings called for the strengthening of HIV prevention interventions in urban areas among HIV positive AGYW who had more than one partner in their lifetime or are patronizing dancing and drinking venues. In Zimbabwe, promotion of CVCT, index testing, male circumcision and condom use should be sustained to engage male sexual partners of both urban and rural HIV positive AGYW in HIV prevention.

The sexual networks of female sex workers and potential HIV transmission risk: an entertainment venue-based study in Shaanxi, China

People involved in commercial sex are thought to be at high risk for human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) transmission. To explore the characteristics of female sex workers’ (FSWs) sexual networks and how FSWs and their sex partners could serve as ‘bridges’ in HIV/AIDS transmission, egocentric sexual networks (where a subject is asked to identify his or her sexual contacts and their relationships) of 66 FSWs in Xi'an city, Shaanxi Province of China, were studied. Convenience sampling was used to collect FSWs’ socio-demographic and sexual behavior data, which we analyzed using social network and descriptive statistical methods. Results show that some egocentric sexual networks were connected by sex partners, and these were integrated into several components of a sexual network. According to centrality indicators, FSWs and their commercial sex partners (especially regular clients) served as key nodes within high-risk groups and as bridges between high-risk groups and the general population. The cluster of high-risk groups with cohesive sub-networks had larger network size (P < 0.001), more complex network structures, and more high-risk members (P < 0.05) than other isolated networks. The sexual network of FSWs was characterized by multiple sexual relations (680), unstable relationships (50.15%), and a high rate of inconsistent condom use with non-commercial sex partners (31.22%). By linking commercial and non-commercial sexual networks, the FSWs and their clients can become effective bridges for HIV/AIDS spread from high-risk groups to the general population.

Population-level adult mortality following the expansion of antiretroviral therapy in Rakai, Uganda

There are limited data on the impact of antiretroviral therapy (ART) on population-level adult mortality in sub-Saharan Africa. We analysed data for 2000-14 from the Rakai Community Cohort Study (RCCS) in Uganda, where free ART was scaled up after 2004. Using non-parametric and parametric (Weibull) survival analysis, we estimated trends in average person-years lived between exact ages 15 and 50, per capita life-years lost to HIV, and the mortality hazards of people living with HIV (PLHIV). Between 2000 and 2014, average adult life-years lived before age 50 increased significantly, from 26.4 to 33.5 years for all women and from 28.6 to 33.8 years for all men. As of 2014, life-years lost to HIV had declined significantly, to 1.3 years among women and 0.4 years among men. Following the roll-out of ART, mortality reductions among PLHIV were initially larger in women than men, but this is no longer the case.

Systematic selection between age and household structure for models aimed at emerging epidemic predictions

Numerous epidemic models have been developed to capture aspects of human contact patterns, making model selection challenging when they fit (often-scarce) early epidemic data equally well but differ in predictions. Here we consider the invasion of a novel directly transmissible infection and perform an extensive, systematic and transparent comparison of models with explicit age and/or household structure, to determine the accuracy loss in predictions in the absence of interventions when ignoring either or both social components. We conclude that, with heterogeneous and assortative contact patterns relevant to respiratory infections, the model’s age stratification is crucial for accurate predictions. Conversely, the household structure is only needed if transmission is highly concentrated in households, as suggested by an empirical but robust rule of thumb based on household secondary attack rate. This work serves as a template to guide the simplicity/accuracy trade-off in designing models aimed at initial, rapid assessment of potential epidemic severity.

Models of emerging epidemics can be exceedingly helpful in planning the response, but early on model selection is a difficult task. Here, the authors explore the joint contribution of age stratification and household structure on epidemic spread, and provides a rule of thumb to guide model choice.

Sexual mixing in opposite-sex partnerships in Britain and its implications for STI risk: findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3)

Background

The extent to which individuals are similar to their sexual partners influences STI-transmission probabilities, yet there is a dearth of empirical data, especially those representative of the population.

Methods

Analyses of data reported by 10 759 sexually active people aged 16–74 y interviewed for a British national probability survey undertaken in 2010–12. Computer-assisted self-interviews asked about partner numbers and characteristics of participants’ three most recent partnerships (MRPs). Opposite-sex MRPs were weighted to represent all such partnerships in the past year (N = 16 451). Estimates of disassortative age mixing (≥±5-y difference), ethnic mixing (partner of a different ethnic group) and geographical mixing (partner from a different region/country when they first met) were calculated, stratified by gender, age group and partnership status (casual/steady). Multivariable regression examined how these disassortative mixing measures were associated with STI-risk measures: condom use at first sex together at the partnership-level and, at the participant-level, STI-risk perception and reporting STI diagnoses.

Results

Disassortative age mixing occurred in around one-third of opposite-sex partnerships, with men ≥5 y older in most cases, although this proportion varied by participant’s gender and age group. Ethnic mixing occurred less frequently (11.3% of men’s and 8.6% of women’s partnerships) as did geographical mixing (14.1 and 16.3%, respectively). Disassortative mixing was more common among casual vs steady partnerships. Condom use at first sex was less likely in women’s partnerships that were age-disassortative [adjusted odds ratio (AOR): 0.79, 95% confidence interval (CI): 0.69–0.95], whereas men reporting disassortative ethnic mixing were more likely to perceive themselves at STI risk (AOR: 1.76, 95% CI: 1.23–2.52) and report STI diagnoses (AOR: 2.37, 95% CI: 1.22–4.59).

Conclusions

Disassortative mixing, although uncommon among opposite-sex partnerships in Britain, is independently associated with STI risk, warranting consideration in STI-prevention efforts.

Evaluating DREAMS HIV prevention interventions targeting adolescent girls and young women in high HIV prevalence districts in South Africa: protocol for a cross-sectional study

BACKGROUND

Young women in sub-Saharan Africa remain at the epicentre of the HIV epidemic, with surveillance data indicating persistent high levels of HIV incidence. In South Africa, adolescent girls and young women (AGYW) account for a quarter of all new HIV infections. Determined, Resilient, Empowered, AIDS-free, Mentored and Safe (DREAMS) is a strategy introduced by the United States President's Emergency Plan for AIDS Relief (PEPFAR) aimed at reducing HIV incidence among AGYW in 10 countries in sub-Saharan Africa by 25% in the programme's first year, and by 40% in the second year. This study will assess the change in HIV incidence and reduction in risk associated behaviours that can be attributed to the DREAMS initiative in South Africa, using a population-based cross-sectional survey.

METHODS

Data will be collected from a household-based representative sample of AGYW (between the ages 12-24 years) in four high prevalence districts (more than 10% of the population have HIV in these districts) in South Africa in which DREAMS has been implemented. A stratified cluster-based sampling approach will be used to select eligible participants for a cross-sectional survey with 18,500, to be conducted over 2017/2018. A questionnaire will be administered containing questions on sexual risk behaviour, selected academic and developmental milestones, prevalence of gender based violence, whilst examining exposure to DREAMS programmes. Biological samples, including two micro-containers of blood and self-collected vulvovaginal swab samples, are collected in each survey to test for HIV infection, HIV incidence, sexually transmitted infections (STIs) and pregnancy. This study will measure trends in population level HIV incidence using the Limiting antigen (LAg) Avidity Enzyme Immuno-Assay (EIA) and monitor changes in HIV incidence.

DISCUSSION

Ending the HIV/AIDS pandemic by 2030 requires the continual monitoring and evaluation of prevention programmes, with the aim of optimising efforts and ensuring the achievement of epidemic control. This study will determine the impact DREAMS interventions have had on HIV incidence among AGYW in a 'real world, non-trial setting'.

Recently formed age-disparate partnerships are associated with elevated HIV-incidence among young women in South Africa

OBJECTIVE

Cross-sectional and cohort studies draw different conclusions on whether age-disparate partnerships increase HIV-acquisition risk for young women. We investigated whether age-disparities were associated with HIV-infection risk early in relationships. This could result in the exclusion of women who seroconverted during high-risk age-disparate partnerships from cohort studies of HIV incidence - which exclude HIV-positive women - and explain null findings in these studies.

DESIGN

Prospective cohort study.

METHODS

We used data on 15-24-year-old, HIV-negative women in heterosexual partnerships (N = 830) in KwaZulu-Natal, South Africa. The association between age-disparate partnering (i.e., male partner ≥5 years older) and subsequent HIV seroconversion was assessed using Cox hazard models. We examined heterogeneity in HIV-acquisition risk by duration of partnership (defined by quartiles) at cohort enrolment.

RESULTS

During 1139 person-years (mean: 1.4 years) of follow-up, 54 (6.5%) women seroconverted, a weighted HIV-incidence estimate of 4.41/100 person-years [95% confidence interval (CI): 3.30-6.06]. HIV-acquisition risk did not differ significantly between women in age-disparate vs. age-similar partnerships (adjusted hazard ratios: 1.10, 95% CI: 0.55-2.21). However, for women in the shortest partnership quartile (<1.09 years) at baseline, risk of HIV seroconversion was higher for women in age-disparate partnerships (adjusted hazard ratios: 3.13, 95% CI: 1.02-9.65, P = 0.047). HIV acquisition was not statistically different by partnership type among women in longer partnerships.

CONCLUSION

The association between age-disparate partnerships and HIV-acquisition risk is evident early in young women's relationships. Results provide a potential explanation for null findings in cohort studies, whose research designs may exclude women in such partnerships, and affirms the elevated risk of HIV acquisition for young women in age-disparate relationships.

Individual and Sexual Network Predictors of HIV Incidence Among Men Who Have Sex With Men in Nigeria

BACKGROUND

To date, HIV incidence studies among men who have sex with men (MSM) across sub-Saharan Africa have focused on studying sexual risk practices with less focus on sexual networks.

SETTING

TRUST/RV368 conducted in Abuja and Lagos, Nigeria, recruited MSM using respondent-driven sampling and followed HIV-negative men for incident infection over 4 years.

METHODS

Four-hundred forty-one HIV-uninfected MSM underwent a parallel rapid HIV testing algorithm every 3 months for up to 18 months. HIV incidence per 100 person-years (PY) and 95% confidence intervals (CIs) were estimated using Poisson regression. Individual and network characteristics were examined using multivariable Cox-proportional hazards regression adjusted and unadjusted for respondent-driven sampling weights.

RESULTS

Among cohort members with a median age of 23 years [interquartile range (IQR): 20-27], 81 HIV infections occurred over 527 PY (incidence 15.4/100 PY; 95% CI: 12.3 to 19.0). The incidence rate was highest among 16-19 year olds as compared to those 25 years or older (30.9/100 PY; 95% CI: 22.1 to 45.3 vs. 6.9/100 PY; 95% CI: 4.2 to 10.9, respectively). Individual determinants included receptive partnerships, condomless sex, no history of testing for HIV, and rectal gonorrhea. Sexual networks were larger and consisted of an older sexual partner, although there was no clustering by recruitment networks.

CONCLUSIONS

These HIV incidence data reinforce the unmet HIV prevention needs among young MSM in Nigeria. Even in the context of emerging HIV diagnostic and prevention strategies, structural challenges including stigma and criminalization of same-sex practices highlight the need for novel implementation approaches in the context of MSM-friendly services.

Characteristics of men who engage in cross-generational sexual behaviour in Nigeria

Cross-generational sexual relationships are a major route of transmitting HIV and STI between older and younger generations. However, previous research has focused mainly on the young women in these relationships. This study examined the characteristics of men engaging in non-marital sexual relationships with girls aged 15-19 in Nigeria. The data were drawn from the 2013 Nigeria Demographic and Health Survey, and the analysis was restricted to a sub-sample of 7557 men aged 30-49 who were sexually active in the 12 months prior to the survey. Data analysis was carried out using frequency distributions, chi-squared tests of association and binary logistic regression. It was found that 9.5% of men aged 30-49 reported engaging in cross-generational sexual relationships. Also, being older (OR = 0.35), married (OR = 0.37), having secondary or higher education (OR = 0.70; 0.59) and having sexual debut between ages 18 and 30 (OR = 0.73) were associated with a lower likelihood of having cross-generational sexual relationships. However, Muslim men (OR = 2.10), men from Igbo (OR = 1.90), Hausa/Fulani (OR = 8.47) and Northern and Southern minority tribes (OR = 4.73; 2.49), men living in rural areas (OR = 1.34), men who were over the age of 30 at sexual debut (OR = 2.67) and those with 2-4 and 5 or more lifetime sexual partners (OR = 1.43; 1.58) were significantly more likely to engage in cross-generational sexual relationships. Addressing the challenges of cross-generational sexual relationships can be an effective strategy to reduce the menace of HIV and STI transmission. Men who have low education, those aged 30-34 years, those who initiated sex at an older age, rural dwellers and those who have had several lifetime sexual partners need to be targeted while designing and implementing programmes and policies to reduce cross-generational sexual relationships in Nigeria. These interventions must also take into account the religious and cultural attitudes towards cross-generational sexual relationships, and further investigations should identify men's motives for engaging in the practice.

Brief Report: Age-Disparate Relationships and HIV Prevalence Among Never Married Women in Rakai, Uganda

BACKGROUND

Age-disparate relationships are associated with increased HIV prevalence. We determined whether the frequency of age-disparate relationships in never married women changed over time and whether they are associated with HIV prevalence in Rakai, Uganda.

METHODS

A total of 10,061 never married women, aged 15-49 years, in the Rakai Community Cohort Study provided information on the age of their male sexual partners from 1997 to 2013. Logistic regression was used to assess trends in age-disparate relationships (≥5 years) between never married women and their male partners. Log-binomial regression was used to estimate adjusted prevalence ratios (adjPR) of HIV prevalence associated with age-disparate relationships.

RESULTS

Two thousand nine hundred ninety-nine women (30%) had a male partner ≥5 years older, which remained stable over time. The prevalence of HIV among women in age-disparate relationships was 14%, 10% for women in relationships with men 0-4 years older (adjPR 1.36, 95% confidence interval: 1.22 to 1.53) not controlling women's age; however, after age adjustment, the impact of age-disparate relationships on HIV prevalence was attenuated. Age-disparate relationships were associated with increased HIV prevalence among women aged 15-17 years (adjPR 1.83, 95% confidence interval: 1.10 to 3.17), but not in other age groups.

CONCLUSIONS

The frequency of age-disparate relationships among never married women was unchanged over a 15-year period in Rakai, Uganda. Age-disparate relationships were associated with increased HIV prevalence among adolescents aged 15-17 years, but not older women.

Adolescent HIV treatment in South Africa's national HIV programme: a retrospective cohort study

BACKGROUND

The number of South African adolescents receiving HIV care and treatment in South Africa is growing. By use of routinely collected laboratory data from South Africa's National HIV Programme, we aimed to quantify the numbers of adolescents accessing HIV care and treatment over time, characterise the role of perinatal infection in these trends, and estimate proportions of adolescents seeking HIV care and antiretroviral therapy (ART) in South Africa's public sector.

METHODS

We did a retrospective, descriptive cohort study of children and adolescents aged 1-19 years accessing care in South Africa's public sector HIV treatment programme from 2005 to 2016 with a CD4 cell count or viral load recorded in South Africa's National Health Laboratory Service database. We estimated the total number of children and adolescents entering HIV care with a CD4 cell count or viral load test result by calendar period, as well as the proportion in care and receiving ART with at least one viral load test result. We stratified analyses by gender and by whether the patient entered care at younger than 15 years (probably perinatally infected) or at 15-19 years (probably infected in adolescence).

FINDINGS

We identified 730 882 patients aged 1-19 years at entry to care between Jan 1, 2005, and Dec 31, 2016. 209 205 (54%) of 388 439 patients entering care younger than 15 years and 301 242 (88%) of 342 443 patients entering care aged 15-19 were female. During the study period, the number of virologically monitored patients aged 15-19 years receiving ART increased from 7949 in 2005-08 to 80 918 in 2013-16. 92 783 (66%) of 140 028 patients aged 15-19 years seeking care started ART by 2016, well below UNAID's target of ART for 90% of those diagnosed. We project that the number of adolescents on ART will continue to rise.

INTERPRETATION

The many adolescents aged 15-19 years receiving ART reflect the ageing of children entering care at ages 1-14 years, and increases in care-seeking among horizontally infected adolescents aged 15-19 years. However, many adolescents seeking care do not start ART, suggesting an urgent need for interventions to increase uptake of ART and improve services for this population.

FUNDING

US National Institutes of Health, and the President's Emergency Plan for AIDS Relief through the US Agency for International Development.

Role of Male Sex Partners in HIV Risk of Adolescent Girls and Young Women in Mozambique

Adolescent girls and young women (AGYW) ages 15-24 years are disproportionately affected by HIV/AIDS, particularly in East and Southern Africa. One strategy to reduce HIV among AGYW, proposed through the Determined, Resilient, Empowered, AIDS-free, Mentored, and Safe (DREAMS) Initiative, is to prevent and manage HIV among their male sexual partners. To implement this strategy and reach men, programs need information about AGYW's potential sexual partners at the local level. To support DREAMS programming in Mozambique, we undertook a study to characterize this population of men in 3 districts with ongoing DREAMS programming. In mid-2017 we conducted 15 focus group discussions with AGYW (N=102) and a venue-based intercept survey of men (N=1,140). Male sexual partners of AGYW who took the survey were diverse in age, education level, and socioeconomic status. Older AGYW focus group participants sought partners who could provide for them financially. Multiple sexual partnerships and inconsistent condom use were widely reported, with AGYW emphasizing that gender norms disempowered them from negotiating condom use. Reported condom use varied by AGYW and male-partner demographic characteristics, as well as by their relationship type. Condom use rates were much higher than national and regional estimates. AGYW who were less educated/not-in-school, were pregnant, or single mothers were particularly disempowered in sexual relationships. Less educated men were less likely to use condoms than educated men, and condom use was least likely in marriage. Study findings underscore the importance of reaching the diversity of male sexual partners of AGYW with HIV services as part of a strategy to reduce HIV risk among AGYW. They also support an enhanced focus on female-controlled HIV prevention methods that do not require negotiation with a male partner and special efforts to reach out-of-school/less educated AGYW, as well as pregnant AGYW and single mothers.

Sexual Partner Types and Incident HIV Infection Among Rural South African Adolescent Girls and Young Women Enrolled in HPTN 068: A Latent Class Analysis

BACKGROUND

Sexual partners are the primary source of incident HIV infection among adolescent girls and young women (AGYW) in sub-Saharan Africa. Identifying partner types at greatest risk of HIV transmission could guide the design of tailored HIV prevention interventions.

METHODS

We conducted a secondary analysis of data from AGYW (aged 13-23 years) enrolled in a randomized controlled trial of cash transfers for HIV prevention in South Africa. Annually, AGYW reported behavioral and demographic characteristics of their 3 most recent sexual partners, categorized each partner using prespecified labels, and received HIV testing. We used latent class analysis (LCA) to identify partner types from reported characteristics, and generalized estimating equations to estimate the relationship between both LCA-identified and prespecified partner types and incident HIV infection.

RESULTS

Across 2140 AGYW visits, 1034 AGYW made 2968 partner reports and 63 AGYW acquired HIV infection. We identified 5 LCA partner types, which we named monogamous HIV-negative peer partner; one-time protected in-school peer partner; out-of-school older partner; anonymous out-of-school peer partner; and cohabiting with children in-school peer partner. Compared to AGYW with only monogamous HIV-negative peer partners, AGYW with out-of-school older partners had 2.56 times the annual risk of HIV infection (95% confidence interval: 1.23 to 5.33), whereas AGYW with anonymous out-of-school peer partners had 1.72 times the risk (95% confidence interval: 0.82 to 3.59). Prespecified partner types were not associated with incident HIV.

CONCLUSION

By identifying meaningful combinations of partner characteristics and predicting the corresponding risk of HIV acquisition among AGYW, LCA-identified partner types may provide new insights for the design of tailored HIV prevention interventions.

Barriers of Mucosal Entry of HIV/SIV

Most new HIV infections, over 80%, occur through sexual transmission. During sexual transmission, the virus must bypass specific female and male reproductive tract anatomical barriers to encounter viable target cells. Understanding the generally efficient ability of these barrier to exclude HIV and the precise mechanisms of HIV translocation beyond these genital barriers is essential for vaccine and novel therapeutic development. In this review, we explore the mucosal, barriers of cervico-vaginal and penile tissues that comprise the female and male reproductive tracts. The unique cellular assemblies f the squamous and columnar epithelium are illustrate highlighting their structure and function. Each anatomical tissue offers a unique barrier to virus entry in healthy individuals. Unfortunately barrier dysfunction can lead to HIV transmission. How these diverse mucosal barriers have the potential to fail is considered, highlighting those anatomical areas that are postulated to offer a weaker barrier and are; therefore, more susceptible to viral ingress. Risk factors, such as sexually transmitted infections, microbiome dysbiosis, and high progestin environments are also associated with increased acquisition of HIV. How these states may affect the integrity of mucosal barriers leading to HIV acquisition are discussed suggesting mechanisms of transmission and revealing potential targets for intervention.

Adolescent lives matter: preventing HIV in adolescents

Purpose of review

Many of the almost 2 million HIV infections that occurred globally in the last year occurred among adolescents and young people, particularly those from East and Southern Africa and within key populations. Global HIV epidemic control will require that new infections among these youth populations be curtailed. This review examines the most effective prevention approaches to reach these adolescent populations in the next 5 years.

Recent findings

Adolescents are in transition and are developmentally unique. They have specific needs and challenges, which if not addressed will result in less than successful interventions. Tailored, layered, combination prevention packages that take into account specific adolescent needs and involve biomedical, behavioural and structural components are recommended. These packages should be designed for and with the meaningful input of adolescents, and involve their peers in their implementation and execution. Where possible, age-appropriate health and social interventions that go beyond HIV should be bundled and offered in a variety of community-based venues that are already acceptable to and frequented by adolescents.

Summary

It is urgent that we reach adolescents globally with the most effective HIV prevention approaches. HIV prevention investment in this population has immediate and longer-term benefits.

Coital frequency and condom use in age-disparate partnerships involving women aged 15 to 24: evidence from a cross-sectional study in KwaZulu-Natal, South Africa

OBJECTIVE

This study examines the role of age-disparate partnerships on young women's HIV risk by investigating coital frequency and condom use within age-disparate partnerships involving women aged 15 to 24.

DESIGN

A community-based, cross-sectional study was conducted.

SETTING

Participants were randomly selected using a two-stage random sampling method in uMgungundlovu district, KwaZulu-Natal, South Africa, between June 2014 and June 2015.

PARTICIPANTS

A total of 1306 15-24-year-old women in an ongoing heterosexual partnership were included in the analysis. Participants had to be a resident in the area for 12 months, and able to provide informed consent and speak one of the local languages (Zulu or English).

PRIMARY AND SECONDARY OUTCOME MEASURES

Sexual frequency was assessed by asking participants how many times they had sex with each partner in the past 12 months. The degree of condomless sex within partnerships was assessed in the survey by asking participants how often they used a condom with their partners.

RESULTS

Age-disparate partnerships were associated with a higher order category (once, 2-5, 6-10, 11-20, >20) of coital frequency (adjusted OR (aOR) 1.32, p<0.05, 95% CI 1.02 to 1.71) and with sex on more than 10 occasions (aOR 1.48, p<0.01, 95% CI 1.12 to 1.96) compared with age-similar partnerships. Age-disparate partnerships were also more likely to involve sex on more than 10 occasions with inconsistent condom use (aOR 1.43, p<0.05, 95% CI 1.04 to 1.96) in the previous 12 months.

CONCLUSION

The finding that increased sexual activity is positively associated with age-disparate partnerships adds to the evidence that age-disparate partnerships pose greater HIV risk for young women. Our study results indicate that interventions to reduce risky sexual behaviour within age-disparate partnerships remain relevant to reducing the high HIV incidence rates among adolescent girls and young women.

Towards UNAIDS Fast-Track goals: targeting priority geographic areas for HIV prevention and care in Zimbabwe

INTRODUCTION

Zimbabwe has made substantial progress towards the Joint United Nations Programme on HIV/AIDS (UNAIDS) targets of 90-90-90 by 2020, with 73% of people living with HIV diagnosed, 87% of those diagnosed on antiretroviral therapy (ART) and 86% of those on ART virally suppressed. Despite this exceptional response, more effort is needed to completely achieve the UNAIDS targets. Here, we conducted a detailed spatial analysis of the geographical structure of the HIV epidemic in Zimbabwe to include geographical prioritization as a key component of their overall HIV intervention strategy.

METHODS

Data were obtained from Zimbabwe Demographic and Health Survey (ZDHS) conducted in 2015 as well as estimations from the Zimbabwe Population-Based HIV Impact Assessment (ZIMPHIA) 2016 report, and other published literature. Data were used to produce high-resolution maps of HIV prevalence. Using these maps combined with the population density maps, we mapped the HIV-infected population lacking ART coverage and viral suppression.

RESULTS

HIV maps for both sexes illustrated similar geographical variation of HIV prevalence within the country. HIV-infected populations lacking ART coverage and viral suppression were concentrated in the main cities and urban settlements such as Bulawayo, Harare, Ruwa and Chitungwiza.

CONCLUSION

Our study showed extensive local variation in HIV disease burden across Zimbabwe for both women and men. The high-resolution maps generated here identified areas wherein high density of HIV-infected individuals are lacking ART coverage and viral suppression. These results suggest that there is need to tailor HIV programmes to address specific local needs to efficiently achieve epidemic control in Zimbabwe.

Age-disparate partnerships and incident HIV infection in adolescent girls and young women in rural South Africa

OBJECTIVE

Adolescent girls and young women (AGYW) have a much higher risk of HIV infection than young men of the same age. One hypothesis for this disparity is AGYW are more likely to be in sexual partnerships with older men with HIV; however, evidence has been inconclusive.

DESIGN

We used longitudinal data from a randomized trial in South Africa (HPTN 068) to determined whether partner age difference is associated with incident HIV infection in AGYW.

METHODS

Age difference was examined continuously and dichotomously (≥5 years). We examined inverse probability of exposure weighted survival curves and calculated time-specific risk differences and risk ratios over 5.5 years of follow-up. We also used a marginal structural Cox model to estimate hazard ratios over the entire study period.

RESULTS

Risk of HIV was higher in AGYW with an age-disparate partnership versus not and the risk difference was largest at later time points. At 5.5 years, AGYW with an age-disparate partnership had a 12.6% (95% confidence interval 1.9-23.3) higher risk than AGYW with no age-disparate partnerships. The weighted hazard ratio was 1.91 (95% confidence interval 1.33-2.74), an association that remained after weighting for either transactional or condomless sex, and after examining continuous age-differences.

CONCLUSION

Age-disparate partnerships increased risk of HIV infection, even after accounting for transactional sex and condomless sex. The relationship between age-disparate partnerships and HIV infection may be explained by increased exposure to infection from men in a higher HIV prevalence pool rather than differences in sexual behaviour within these partnerships.

Economy, migrant labour and sex work: interplay of HIV epidemic drivers in Zimbabwe over three decades

BACKGROUND

HIV took off rapidly in Zimbabwe during the 1980s. Yet, between 1998 and 2003, as the economy faltered, HIV prevalence declined abruptly and without clear explanation.

METHODS

We reviewed epidemiological, behavioural, and economic data over three decades to understand changes in economic conditions, migrant labour and sex work that may account for observed fluctuations in Zimbabwe's HIV epidemic. Potential biases related to changing epidemic paradigms and data sources were examined.

RESULTS

Early studies describe rural poverty, male migrant labour and sex work as conditions facilitating HIV/sexually transmitted infection (STI) transmission. By the mid-1990s, as Zimbabwe's epidemic became more generalized, research focus shifted to general population household surveys. Yet, less than half as many men than women were found at home during surveys in the 1990s, increasing to 80% during the years of economic decline. Other studies suggest that male demand for sex work fell abruptly as migrant workers were laid off, picking up again when the economy rebounded after 2009. Numbers of clients reported by sex workers, and their STI rates, followed similar patterns reaching a nadir in the early 2000s. Studies from 2009 describe a return to more active sex work, linked to increasing client demand, as well as a revitalized programme reaching sex workers.

CONCLUSION

The importance of the downturn in migrant labour and resultant changes in sex work may be underestimated as drivers of Zimbabwe's rapid HIV incidence and prevalence declines. Household surveys underrepresent populations at the highest risk of HIV/STI acquisition and transmission, and these biases vary with changing economic conditions.