Understanding the potential impact of a combination HIV prevention intervention in a hyper-endemic community

Who is Exposed to HIV Prevention Interventions? An Assessment of Associated Factors Among Adolescent Girls and Young Women in South Africa

This study examined the prevalence of HIV risk factors and their association with intervention exposure among adolescent girls and young women (AGYW) living in six South African districts in which a combination HIV-prevention intervention was being implemented. A cross-sectional household survey was conducted from 2017 to 2018 among a representative sample of AGYW aged 15-24 years living in the six districts. We used an electronic questionnaire for self-reported demographic and behavioural questions and blood samples were taken to confirm HIV status in the laboratory. Chi-Squared tests and multivariate binary logistic regression were used to examine associations between demographic characteristics, HIV acquisition and transmission risk factors and the likelihood of participating in any of the key components of the combination HIV-prevention intervention. Among the 4399 participants, 45.3% reported inconsistent condom use with casual partner and 46.6% with a main partner. Almost half of participants (47.8%) had participated in one or more components of the HIV-prevention intervention, and in a multivariate logistic regression, those reporting a higher number of HIV risk behaviours were no more (or less) likely to participate. Participants who were not in high school were significantly less likely to have participated in the intervention compared to those still in high school, when adjusting for age and HIV risk factors. The barriers to access and uptake of combination HIV prevention interventions among AGYW who are out of the education system need to be explored and combination HIV prevention interventions and implementation strategies need to be tailored to reach this population.

The Effect of HIV Programs in South Africa on National HIV Incidence Trends, 2000-2019

BACKGROUND

Recent studies have shown HIV incidence declines at a population level in several African countries. However, these studies have not directly quantified the extent to which incidence declines are attributable to different HIV programs.

METHODS

We calibrated a mathematical model of the South African HIV epidemic to age- and sex-specific data from antenatal surveys, household surveys, and death registration, using a Bayesian approach. The model was also parameterized using data on self-reported condom use, voluntary medical male circumcision (VMMC), HIV testing, and antiretroviral treatment (ART). Model estimates of HIV incidence were compared against the incidence rates that would have been expected had each program not been implemented.

RESULTS

The model estimated incidence in 15-49 year olds of 0.84% (95% CI: 0.75% to 0.96%) at the start of 2019. This represents a 62% reduction (95% CI: 55% to 66%) relative to 2000, a 47% reduction (95% CI: 42% to 51%) relative to 2010, and a 73% reduction (95% CI: 68% to 77%) relative to the incidence that would have been expected in 2019 in the absence of any interventions. The reduction in incidence in 2019 because of interventions was greatest for ART and condom promotion, with VMMC and behavior change after HIV testing having relatively modest impacts. HIV program impacts differed significantly by age and sex, with condoms and VMMC having greatest impact in youth, and overall incidence reductions being greater in men than in women.

CONCLUSIONS

HIV incidence in South Africa has declined substantially since 2000, with ART and condom promotion contributing most significantly to this decline.

Effects of community-based antiretroviral therapy initiation models on HIV treatment outcomes: A systematic review and meta-analysis

BACKGROUND

Antiretroviral therapy (ART) initiation in the community and outside of a traditional health facility has the potential to improve linkage to ART, decongest health facilities, and minimize structural barriers to attending HIV services among people living with HIV (PLWH). We conducted a systematic review and meta-analysis to determine the effect of offering ART initiation in the community on HIV treatment outcomes.

METHODS AND FINDINGS

We searched databases between 1 January 2013 and 22 February 2021 to identify randomized controlled trials (RCTs) and observational studies that compared offering ART initiation in a community setting to offering ART initiation in a traditional health facility or alternative community setting. We assessed risk of bias, reporting of implementation outcomes, and real-world relevance and used Mantel-Haenszel methods to generate pooled risk ratios (RRs) and risk differences (RDs) with 95% confidence intervals. We evaluated heterogeneity qualitatively and quantitatively and used GRADE to evaluate overall evidence certainty. Searches yielded 4,035 records, resulting in 8 included studies-4 RCTs and 4 observational studies-conducted in Lesotho, South Africa, Nigeria, Uganda, Malawi, Tanzania, and Haiti-a total of 11,196 PLWH. Five studies were conducted in general HIV populations, 2 in key populations, and 1 in adolescents. Community ART initiation strategies included community-based HIV testing coupled with ART initiation at home or at community venues; 5 studies maintained ART refills in the community, and 4 provided refills at the health facility. All studies were pragmatic, but in most cases provided additional resources. Few studies reported on implementation outcomes. All studies showed higher ART uptake in community initiation arms compared to facility initiation and refill arms (standard of care) (RR 1.73, 95% CI 1.22 to 2.45; RD 30%, 95% CI 10% to 50%; 5 studies). Retention (RR 1.43, 95% CI 1.32 to 1.54; RD 19%, 95% CI 11% to 28%; 4 studies) and viral suppression (RR 1.31, 95% CI 1.15 to 1.49; RD 15%, 95% CI 10% to 21%; 3 studies) at 12 months were also higher in the community-based ART initiation arms. Improved uptake, retention, and viral suppression with community ART initiation were seen across population subgroups-including men, adolescents, and key populations. One study reported no difference in retention and viral suppression at 2 years. There were limited data on adherence and mortality. Social harms and adverse events appeared to be minimal and similar between community ART initiation and standard of care. One study compared ART refill strategies following community ART initiation (community versus facility refills) and found no difference in viral suppression (RD -7%, 95% CI -19% to 6%) or retention at 12 months (RD -12%, 95% CI -23% to 0.3%). This systematic review was limited by few studies for inclusion, poor-quality observational data, and short-term outcomes.

CONCLUSIONS

Based on data from a limited set of studies, community ART initiation appears to result in higher ART uptake, retention, and viral suppression at 1 year compared to facility-based ART initiation. Implementation on a wider scale necessitates broader exploration of costs, logistics, and acceptability by providers and PLWH to ensure that these effects are reproducible when delivered at scale, in different contexts, and over time.

A review of network simulation models of hepatitis C virus and HIV among people who inject drugs

Network modelling is a valuable tool for simulating hepatitis C virus (HCV) and HIV transmission among people who inject drugs (PWID) and assessing the potential impact of treatment and harm-reduction interventions. In this paper, we review literature on network simulation models, highlighting key structural considerations and questions that network models are well suited to address. We describe five approaches (Erdös-Rényi, Stochastic Block, Watts-Strogatz, Barabási-Albert, and Exponential Random Graph Model) used to model partnership formation with emphasis on the strengths of each approach in simulating different features of real-world PWID networks. We also review two important structural considerations when designing or interpreting results from a network simulation study: (1) dynamic vs. static network and (2) injection only vs. both injection and sexual networks. Dynamic network simulations allow partnerships to evolve and disintegrate over time, capturing corresponding shifts in individual and population-level risk behaviour; however, their high level of complexity and reliance on difficult-to-observe data has driven others to develop static network models. Incorporating both sexual and injection partnerships increases model complexity and data demands, but more accurately represents HIV transmission between PWID and their sexual partners who may not also use drugs. Network models add the greatest value when used to investigate how leveraging network structure can maximize the effectiveness of health interventions and optimize investments. For example, network models have shown that features of a given network and epidemic influence whether the greatest community benefit would be achieved by allocating hepatitis C or HIV treatment randomly, versus to those with the most partners. They have also demonstrated the potential for syringe services and "buddy sharing" programs to reduce disease transmission.

Using mHealth to Deliver a Home-Based Testing and Counseling Program to Improve Linkage to Care and ART Adherence in Rural South Africa

Community-based HIV testing and counseling (HTC) programs have become an important part of the healthcare system in South Africa and other low- and middle-income countries with a high HIV prevalence and strained primary healthcare system. Current HTC programs excel at identifying people living with HIV (PLH) but leave gaps in linkage to care and antiretroviral therapy (ART) as most HTC programs do not have the capacity to ensure that linkage has occurred. This article presents the protocol for an mHealth study, that is, pilot testing a mobile platform in KwaZulu-Natal (KZN), South Africa, to improve linkage to care and ART adherence after home-based HTC. Testing data are shared with designated clinics. PLH are identified using fingerprint scans, mobile numbers, or South African IDs. If PLH do not present at a designated clinic after testing HIV positive, study field staff are sent SMS alerts to prompt follow-up visits. Similarly, if PLH do not refill ART prescriptions after their initial 1-month dose runs out, SMS alerts that are sent to field staff. This paper presents the mHealth study protocol and baseline sample characteristics (N = 101 PLH). Analyses will summarize rates of linkage to care and ART prescription refills. Cost-effectiveness analyses will examine the costs and benefits of linkage and ART adherence using our mHealth system. Linkage to care rates will be compared between our study and a historical control, that is, provided by a prior HTC program that was conducted in KZN without our mHealth system (n = 615).

Completion of the tuberculosis care cascade in a community-based HIV linkage-to-care study in South Africa and Uganda

INTRODUCTION

Tuberculosis (TB) is the leading cause of HIV-associated mortality in Africa. As HIV testing, linkage to care and antiretroviral treatment initiation intensify to meet UNAIDS targets, it is not known what effect these efforts will have on TB detection and prevention. We aimed to characterize the TB care cascade of screening, diagnostic testing, treatment and provision of isoniazid preventive therapy (IPT) in a study of community-based HIV screening and linkage to care and determine whether symptom screening results affected progress along the cascade.

METHODS

Between June 2013 and March 2015, HIV-infected adults enrolled in the Linkages study, a multi-site, community-based, randomized HIV screening and linkage-to-care study in South Africa and Uganda. All participants were screened for TB symptoms at entry after testing positive for HIV and referred to local clinics for care. During the 9 month follow-up, participants were periodically surveyed about clinic linkage and initiation of HIV care as well as subsequent TB testing, treatment, or IPT. We compared outcomes between persons with and without a positive symptom screen at baseline using descriptive statistics and Poisson regression to calculate relative risks of outcomes along the care cascade.

RESULTS AND DISCUSSION

Of the 1,325 HIV-infected adults enrolled, 26% reported at least one TB symptom at the time of HIV diagnosis. Loss of appetite and fever were the most commonly reported symptoms on a TB symptom screen. Despite 92% HIV linkage success, corresponding TB linkage was incomplete. Baseline TB symptoms were associated with an increased risk of a TB diagnosis (relative risk 3.23, 95% CI 1.51 to 6.91), but only 34% of symptomatic persons had sputum TB testing. Fifty-five percent of participants diagnosed with TB started TB treatment. In South Africa, only 18% of asymptomatic participants initiated IPT after linkage to HIV care, and presence of symptoms was not associated with IPT initiation (relative risk 0.86 95% CI 0.6 to 1.23).

CONCLUSIONS

HIV linkage to care interventions provide an opportunity to improve completion of the TB care cascade, but will require additional support to realize full benefits.

Phylogeography of HIV-1 suggests that Ugandan fishing communities are a sink for, not a source of, virus from general populations

Although fishing communities (FCs) in Uganda are disproportionately affected by HIV-1 relative to the general population (GP), the transmission dynamics are not completely understood. We earlier found most HIV-1 transmissions to occur within FCs of Lake Victoria. Here, we test the hypothesis that HIV-1 transmission in FCs is isolated from networks in the GP. We used phylogeography to reconstruct the geospatial viral migration patterns in 8 FCs and 2 GP cohorts and a Bayesian phylogenetic inference in BEAST v1.8.4 to analyse the temporal dynamics of HIV-1 transmission. Subtype A1 (pol region) was most prevalent in the FCs (115, 45.1%) and GP (177, 50.4%). More recent HIV transmission pairs from FCs were found at a genetic distance (GD) <1.5% than in the GP (Fisher’s exact test, p = 0.001). The mean time depth for pairs was shorter in FCs (5 months) than in the GP (4 years). Phylogeographic analysis showed strong support for viral migration from the GP to FCs without evidence of substantial viral dissemination to the GP. This suggests that FCs are a sink for, not a source of, virus strains from the GP. Targeted interventions in FCs should be extended to include the neighbouring GP for effective epidemic control.

High prevalence of HIV and non-communicable disease (NCD) risk factors in rural KwaZulu-Natal, South Africa

INTRODUCTION

South Africa faces epidemics of HIV and non-communicable diseases (NCDs). The aim of this study was to characterize the prevalence of non-communicable disease risk factors and depression, stratified by HIV status, in a community with a high burden of HIV.

METHODS

We conducted a home-based HIV counselling and testing study in KwaZulu-Natal, South Africa between November 2011 and June 2012. Contiguous households were approached and all adults ≥18 years old were offered an HIV test. During follow-up visits in January 2015, screening for HIV, depression, obesity, blood glucose, cholesterol and blood pressure were conducted using point-of-care tests.

RESULTS

Of the 570 participants located and screened; 69% were female and 33% were HIV-positive. NCD risk factor prevalence was high in this sample; 71% were overweight (body mass index (BMI) 25 to 29.9 kg/m² ) or obese (BMI≥30 kg/m² ), 4% had hyperglycaemia (plasma glucose >11.0 mmol/l/200 mg/dl), 33% had hypertension (HTN, >140/90 mmHg), 20% had hyperlipidaemia (low density cholesterol >5.2 mmol/l/193.6 mg/dl) and 12% had major depressive symptoms (nine item Patient Health Questionnaire ≥10). Of the 570 participants, 87% had one or more of HIV, hyperglycaemia, HTN, hyperlipidaemia and/or depression. Over half (56%) had two or more. Older age and female gender were significantly associated with the prevalence of both HIV infection and NCD risk factors. Around 80% of both HIV-positive and negative persons had one of the measured risk factors (i.e. obesity, hyperglycaemia, hyperlipidaemia, HTN), or depression.

CONCLUSIONS

In a community-based sample of adults in KwaZulu-Natal, South Africa, the prevalence of both HIV infection and NCD risk factors were high. This study is among the first to quantify the substantial burden of NCD risk factors and depression in this non-clinic based population.

HIV Prevention Efforts and Incidence of HIV in Uganda

BACKGROUND

To assess the effect of a combination strategy for prevention of human immunodeficiency virus (HIV) on the incidence of HIV infection, we analyzed the association between the incidence of HIV and the scale-up of antiretroviral therapy (ART) and medical male circumcision in Rakai, Uganda. Changes in population-level viral-load suppression and sexual behaviors were also examined.

METHODS

Between 1999 and 2016, data were collected from 30 communities with the use of 12 surveys in the Rakai Community Cohort Study, an open, population-based cohort of persons 15 to 49 years of age. We assessed trends in the incidence of HIV on the basis of observed seroconversion data, participant-reported use of ART, participant-reported male circumcision, viral-load suppression, and sexual behaviors.

RESULTS

In total, 33,937 study participants contributed 103,011 person-visits. A total of 17,870 persons who were initially HIV-negative were followed for 94,427 person-years; among these persons, 931 seroconversions were observed. ART was introduced in 2004, and by 2016, ART coverage was 69% (72% among women vs. 61% among men, P<0.001). HIV viral-load suppression among all HIV-positive persons increased from 42% in 2009 to 75% by 2016 (P<0.001). Male circumcision coverage increased from 15% in 1999 to 59% by 2016 (P<0.001). The percentage of adolescents 15 to 19 years of age who reported never having initiated sex (i.e., delayed sexual debut) increased from 30% in 1999 to 55% in 2016 (P<0.001). By 2016, the mean incidence of HIV infection had declined by 42% relative to the period before 2006 (i.e., before the scale-up of the combination strategy for HIV prevention) - from 1.17 cases per 100 person-years to 0.66 cases per 100 person-years (adjusted incidence rate ratio, 0.58; 95% confidence interval [CI], 0.45 to 0.76); declines were greater among men (adjusted incidence rate ratio, 0.46; 95% CI, 0.29 to 0.73) than among women (adjusted incidence rate ratio, 0.68; 95% CI, 0.50 to 0.94).

CONCLUSIONS

In this longitudinal study, the incidence of HIV infection declined significantly with the scale-up of a combination strategy for HIV prevention, which provides empirical evidence that interventions for HIV prevention can have a population-level effect. However, additional efforts are needed to overcome disparities according to sex and to achieve greater reductions in the incidence of HIV infection. (Funded by the National Institute of Allergy and Infectious Diseases and others.).

Combined interventions to reduce HIV incidence in KwaZulu-Natal: a modelling study

BACKGROUND

Combined prevention interventions, including early antiretroviral therapy initiation, may substantially reduce HIV incidence in hyperendemic settings. Our aim was to assess the potential short-term impact of combined interventions on HIV spreading in the adult population of Mbongolwane and Eshowe (KwaZulu-Natal, South Africa) using sex- and age-specific scenarios, and age-targeted interventions.

METHODS

A mathematical model was used with data on adults (15-59 years) from the Mbongolwane and Eshowe HIV Impact in Population Survey to compare the effects of various interventions on the HIV incidence rate. These interventions included increase in antiretroviral therapy (ART) coverage with extended eligibility criteria, increase in voluntary medical male circumcision (VMMC), and implementation of pre-exposure prophylaxis (PrEP) among women.

RESULTS

With no additional interventions to the ones in place at the time of the survey (ART at CD4 < 350 and VMMC), incidence will decrease by 24% compared to the baseline rate. The implementation of "ART at CD4<500" or "ART for all" would reduce further the incidence rate by additional 8% and 15% respectively by 4 years and 20% and 34% by 10 years. Impacts would be higher with age-targeted scenarios than without.

CONCLUSIONS

In Mbongolwane and Eshowe, implementation of the new South African guidelines, recommending ART initiation regardless of CD4 count, would accelerate incidence reduction. In this setting, combining these guidelines, VMMC, and PrEP among young women could be an effective strategy in reducing the incidence to low levels.

Factors associated with changes in uptake of HIV testing among young women (aged 15-24) in Tanzania from 2003 to 2012

Background

This study explored the factors associated with changes in HIV testing uptake among young women in Tanzania, based on an analysis of data from the 2003–2004 Tanzania HIV/AIDS Indicator Survey, and the 2007–2008 and 2011–2012 Tanzania HIV/AIDS and Malaria Indicator Surveys.

Methods

The study population consisted of young women aged 15–24 years at the time of the survey. Multivariate decomposition analysis was used to assess factors associated with changes in HIV testing uptake between the 2003–2004 and 2007–2008 surveys, and between the 2007–2008 and 2011–2012 surveys.

Results

HIV testing uptake among the study population was 7 % in 2003–2004, 31 % in 2007–2008 and 40 % in 2011–2012. The time period of the survey had a substantial effect on the uptake of HIV testing independent of other covariates. The characteristics that were significantly associated with a higher chance of HIV testing uptake across the surveys were age (20–24), education level (primary and secondary), ever being married, having at least one lifetime sexual partner, having a sexually transmitted infection or associated symptoms, and receiving antenatal care.

Conclusions

Changes in the study participants’ characteristics in the 2003–2004 survey compared with the 2007–2008 survey were associated with a decrease in HIV testing uptake. Comparing the 2007–2008 survey with the 2011–2012 survey shows that the changes in the participants’ characteristics contributed to 22 % of the changes in HIV testing uptake, while 78 % of the changes were attributed to coefficients.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-016-0180-3) contains supplementary material, which is available to authorized users.

Prevention and treatment produced large decreases in HIV incidence in a model of people who inject drugs

In the United States, people who inject drugs continue to be at greatly increased risk of HIV infection. To estimate the effectiveness of various prevention scenarios, we modeled HIV transmission in a dynamic network of drug users and people who did not use drugs that was based on the New York Metropolitan Statistical Area population. We compared the projected HIV incidence in 2020 and 2040 if current approaches continue to be used to the incidence if one or more of the following hypothetical interventions were applied: increased HIV testing, improved access to substance abuse treatment, increased use of needle and syringe programs, scaled-up treatment as prevention, and a "high impact" combination scenario, consisting of all of the strategies listed above. No strategy completely eliminated HIV transmission. The high-impact combination strategy produced the largest decrease in HIV incidence-a 62 percent reduction compared to the status quo. Our results suggest that increased resources for and investments in multiple HIV prevention approaches will be required to eliminate HIV transmission among people who inject drugs.

Estimating the impact of universal antiretroviral therapy for HIV serodiscordant couples through home HIV testing: insights from mathematical models

INTRODUCTION

Antiretroviral therapy (ART) prevents HIV transmission within HIV serodiscordant couples (SDCs), but slow implementation and low uptake has limited its impact on population-level HIV incidence. Home HIV testing and counselling (HTC) campaigns could increase ART uptake among SDCs by incorporating couples' testing and ART referral. We estimated the reduction in adult HIV incidence achieved by incorporating universal ART for SDCs into home HTC campaigns in KwaZulu-Natal (KZN), South Africa, and southwestern (SW) Uganda.

METHODS

We constructed dynamic, stochastic, agent-based network models for each region. We compared adult HIV incidence after 10 years under three scenarios: (1) "Current Practice," (2) "Home HTC" with linkage to ART for eligible persons (CD4 <350) and (3) "ART for SDCs" regardless of CD4, delivered alongside home HTC.

RESULTS

ART for SDCs reduced HIV incidence by 38% versus Home HTC: from 1.12 (95% CI: 0.98-1.26) to 0.68 (0.54-0.82) cases per 100 person-years (py) in KZN, and from 0.56 (0.50-0.62) to 0.35 (0.30-0.39) cases per 100 py in SW Uganda. A quarter of incident HIV infections were averted over 10 years, and the proportion of virally suppressed HIV-positive persons increased approximately 15%.

CONCLUSIONS

Using home HTC to identify SDCs and deliver universal ART could avert substantially more new HIV infections than home HTC alone, with a smaller number needed to treat to prevent new HIV infections. Scale-up of home HTC will not diminish the effectiveness of targeting SDCs for treatment. Increasing rates of couples' testing, disclosure, and linkage to care is an efficient way to increase the impact of home HTC interventions on HIV incidence.

Potential impact of multiple interventions on HIV incidence in a hyperendemic region in Western Kenya: a modelling study

BACKGROUND

Multiple prevention interventions, including early antiretroviral therapy initiation, may reduce HIV incidence in hyperendemic settings. Our aim was to predict the short-term impact of various single and combined interventions on HIV spreading in the adult population of Ndhiwa subcounty (Nyanza Province, Kenya).

METHODS

A mathematical model was used with data on adults (15-59 years) from the Ndhiwa HIV Impact in Population Survey to compare the impacts on HIV prevalence, HIV incidence rate, and population viral load suppression of various interventions. These interventions included: improving the cascade of care (use of three guidelines), increasing voluntary medical male circumcision (VMMC), and implementing pre-exposure prophylaxis (PrEP) use among HIV-uninfected women.

RESULTS

After four years, improving separately the cascade of care under the WHO 2013 guidelines and under the treat-all strategy would reduce the overall HIV incidence rate by 46 and 58 %, respectively, vs. the baseline rate, and by 35 and 49 %, respectively, vs. the implementation of the current Kenyan guidelines. With conservative and optimistic scenarios, VMMC and PrEP would reduce the HIV incidence rate by 15-25 % and 22-28 % vs. the baseline, respectively. Combining the WHO 2013 guidelines with VMMC would reduce the HIV incidence rate by 35-56 % and combining the treat-all strategy with VMMC would reduce it by 49-65 %. Combining the WHO 2013 guidelines, VMMC, and PrEP would reduce the HIV incidence rate by 46-67 %.

CONCLUSIONS

The impacts of the WHO 2013 guidelines and the treat-all strategy were relatively close; their implementation is desirable to reduce HIV spread. Combining several strategies is promising in adult populations of hyperendemic areas but requires regular, reliable, and costly monitoring.

Uptake of antiretroviral therapy and male circumcision after community-based HIV testing and strategies for linkage to care versus standard clinic referral: a multisite, open-label, randomised controlled trial in South Africa and Uganda

BACKGROUND

Male circumcision decreases HIV acquisition by 60%, and antiretroviral therapy (ART) almost eliminates HIV transmission from HIV-positive people who are virally suppressed; however, coverage of these interventions has lagged behind targets. We aimed to assess whether community-based HIV testing with counsellor support and point-of-care CD4 cell count testing would increase uptake of ART and male circumcision.

METHODS

We did this multisite, open-label, randomised controlled trial in six research-naive communities in rural South Africa and Uganda. Eligible HIV-positive participants (aged ≥16 years) were randomly assigned (1:1:1) in a factorial design to receive lay counsellor clinic linkage facilitation, lay counsellor follow-up home visits, or standard-of-care clinic referral, and then (1:1) either point-of-care CD4 cell count testing or referral for CD4 testing. HIV-negative uncircumcised men (aged 16-49 years) who could receive secure mobile phone text messages were randomly assigned (1:1:1) to receive text message reminders, lay counsellor visits, or standard clinic referral. The study biostatistician generated the randomisation schedule via a computer-generated random number program with varying block sizes (multiples of six or three) stratified by country. Primary outcomes for HIV-positive people were obtaining a CD4 cell count, linkage to an HIV clinic, ART initiation, and viral suppression at 9 months, and for HIV-negative uncircumcised men were visiting a circumcision facility and uptake of male circumcision at 3 months. We assessed social harms as a safety outcome throughout the study. We did the primary analyses by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT02038582.

FINDINGS

Between June 6, 2013, and March 11, 2015, 15 332 participants were tested. 2339 (15%) participants tested HIV positive, of whom 1325 (57%) were randomly assigned to receive lay counsellor clinic linkage facilitation (n=437), lay counsellor follow-up home visits (n=449), or standard clinic referral (n=439), and then point-of-care CD4 cell testing (n=206, n=220, and n=213, respectively) or referral for CD4 testing (n=231, n=229, and n=226, respectively). 12 993 (85%) participants tested HIV negative, of whom 750 (6%) uncircumcised men were randomly assigned to receive clinic referral (n=230), text message reminders (n=288), or lay counsellor follow-up visits (n=232). 1218 (93%) of 1303 HIV-positive participants were linked to care, but only 488 (37%) participants initiated ART. Overall, 635 (50%) of 1272 HIV-positive individuals achieved viral suppression at 9 months: 219 (52%) of 419 participants in the clinic facilitation group, 202 (47%) of 431 participants in the lay counsellor follow-up group, and 214 (51%) of 422 participants in the clinic referral group, with no significant differences between groups (p=0·668 for clinic facilitation and p=0·273 for lay counsellor follow-up vs clinic referral). 523 (72%) of 734 HIV-negative men visited a circumcision facility, with no difference between groups. 62 (28%) of 224 men were circumcised in the male circumcision clinic referral group compared with 137 (48%) of 284 men in the text message reminder group (relative risk 1·72, 95% CI 1·36-2·17; p<0·0001) and 106 (47%) of 226 men in the lay counsellor follow-up group (1·67, 1·29-2·14; p=0·0001). No cases of study-related social harm were reported, including probing about partnership separation, unintended disclosure, gender-based violence, and stigma.

INTERPRETATION

All the community-based strategies achieved high rates of linkage of HIV-positive people to HIV clinics, roughly a third of whom initiated ART, and of those more than 80% were virally suppressed at 9 months. Uptake of male circumcision was almost two-times higher in men who received text message reminders or lay counsellor visits than in those who received standard-of-care clinic referral. Clinic barriers to ART initiation should be addressed in future strategies to increase the proportion of HIV-positive people accessing treatment and achieving viral suppression.

FUNDING

National Institute of Allergy and Infectious Diseases, National Institutes of Health.

Current issues in the design and analysis of stepped wedge trials

The use of stepped wedge designs in cluster-randomized trials and implementation studies has increased rapidly in recent years but there remains considerable debate regarding the merits of the design. We discuss three key issues in the design and analysis of stepped wedge trials - time-on-treatment effects, treatment effect heterogeneity and cohort studies.

Combination HIV prevention interventions: the potential of integrated behavioral and biomedical approaches

Combination HIV prevention interventions that integrate efficacious behavioral and biomedical strategies offer the potential to reduce new HIV infections. We overview the efficacy data for three biomedical HIV prevention approaches, namely microbicides, pre-exposure prophylaxis (PrEP), and HIV vaccination; review factors associated with differential acceptability and uptake of these methods; and suggest strategies to optimize the effectiveness and dissemination of combination HIV prevention approaches. A narrative review was conducted highlighting key efficacy data for microbicides, PrEP, and an HIV vaccination and summarizing acceptability data for each of the three biomedical HIV prevention approaches. Recommendations for the integration and dissemination of combined behavioral and biomedical HIV prevention approaches are provided. To date, microbicides and an HIV vaccination have demonstrated limited efficacy for the prevention of HIV. However, PrEP has demonstrated efficacy in reducing HIV incident infections. A diverse array of factors influences both hypothetical willingness and actual usage of each biomedical prevention method. Strategies to effectively integrate and evaluate combination HIV prevention interventions are urgently needed.

Estimation and Short-Term Prediction of the Course of the HIV Epidemic Using Demographic and Health Survey Methodology-Like Data

BACKGROUND

Mathematical models have played important roles in the understanding of epidemics and in the study of the impacts of various behavioral or medical measures. However, modeling accurately the future spread of an epidemic requires context-specific parameters that are difficult to estimate because of lack of data. Our objective is to propose a methodology to estimate context-specific parameters using Demographic and Health Survey (DHS)-like data that can be used in mathematical modeling of short-term HIV spreading.

METHODS AND FINDINGS

The model splits the population according to sex, age, HIV status, and antiretroviral treatment status. To estimate context-specific parameters, we used individuals' histories included in DHS-like data and a statistical analysis that used decomposition of the Poisson likelihood. To predict the course of the HIV epidemic, sex- and age-specific differential equations were used. This approach was applied to recent data from Kenya. The approach allowed the estimation of several key epidemiological parameters. Women had a higher infection rate than men and the highest infection rate in the youngest age groups (15-24 and 25-34 years) whereas men had the highest infection rate in age group 25-34 years. The immunosuppression rates were similar between age groups. The treatment rate was the highest in age group 35-59 years in both sexes. The results showed that, within the 15-24 year age group, increasing male circumcision coverage and antiretroviral therapy coverage at CD4 ≤ 350/mm3 over the current 70% could have short-term impacts.

CONCLUSIONS

The study succeeded in estimating the model parameters using DHS-like data rather than literature data. The analysis provides a framework for using the same data for estimation and prediction, which can improve the validity of context-specific predictions and help designing HIV prevention campaigns.

Cost-effectiveness of community-based strategies to strengthen the continuum of HIV care in rural South Africa: a health economic modelling analysis

BACKGROUND

Home HIV counselling and testing (HTC) achieves high coverage of testing and linkage to care compared with existing facility-based approaches, particularly among asymptomatic individuals. In a modelling analysis we aimed to assess the effect on population-level health and cost-effectiveness of a community-based package of home HTC in KwaZulu-Natal, South Africa.

METHODS

We parameterised an individual-based model with data from home HTC and linkage field studies that achieved high coverage (91%) and linkage to antiretroviral therapy (80%) in rural KwaZulu-Natal, South Africa. Costs were derived from a linked microcosting study. The model simulated 10,000 individuals over 10 years and incremental cost-effectiveness ratios were calculated for the intervention relative to the existing status quo of facility-based testing, with costs discounted at 3% annually.

FINDINGS

The model predicted implementation of home HTC in addition to current practice to decrease HIV-associated morbidity by 10–22% and HIV infections by 9–48% with increasing CD4 cell count thresholds for antiretroviral therapy initiation. Incremental programme costs were US$2·7 million to $4·4 million higher in the intervention scenarios than at baseline, and costs increased with higher CD4 cell count thresholds for antiretroviral therapy initiation; antiretroviral therapy accounted for 48–87% of total costs. Incremental cost-effectiveness ratios per disability-adjusted life-year averted were $1340 at an antiretroviral therapy threshold of CD4 count lower than 200 cells per μL, $1090 at lower than 350 cells per μL, $1150 at lower than 500 cells per μL, and $1360 at universal access to antiretroviral therapy.

INTERPRETATION

Community-based HTC with enhanced linkage to care can result in increased HIV testing coverage and treatment uptake, decreasing the population burden of HIV-associated morbidity and mortality. The incremental cost-effectiveness ratios are less than 20% of South Africa's gross domestic product per person, and are therefore classed as very cost effective. Home HTC can be a viable means to achieve UNAIDS' ambitious new targets for HIV treatment coverage.

FUNDING

National Institutes of Health, Bill & Melinda Gates Foundation, Wellcome Trust.

A lifecycle approach to HIV prevention in African women and children

Effective biomedical and structural HIV prevention approaches are being implemented throughout sub-Saharan Africa. A "lifecycle approach" to HIV prevention recognizes the interconnectedness of the health of women, children and adolescents, and prioritizes interventions that have benefits across these populations. We review new biomedical prevention strategies for women, adolescents and children, structural prevention approaches, and new modalities for eliminating infant HIV infection, and discuss the implications of a lifecycle approach for the success of these methods. Some examples of the lifecycle approach include evaluating education and HIV prevention strategies among adolescent girls not only for their role in reducing risk of HIV infection and early pregnancy, but also to promote healthy adolescents who will have healthier future children. Similarly, early childhood interventions such as exclusive breastfeeding not only prevent HIV, but also contribute to better child and adolescent health outcomes. The most ambitious biomedical infant HIV prevention effort, Option B+, also represents a lifecycle approach by leveraging the prevention benefits of optimal HIV treatment for mothers; maternal survival benefits from Option B+ may have ultimately more health impact on children than the prevention of infant HIV in isolation. The potential for synergistic and additive benefits of lifecycle interventions should be considered when scaling up HIV prevention efforts in sub-Saharan Africa.

HIV treatment as prevention: contradictory perspectives from dynamic mathematical models

The preventative effects of antiretroviral therapy for people with HIV have been debated since they were first raised. Models commenced studying the preventive effects of treatment in the 1990s, prior to initial public reports. However, the outcomes of the preventive effects of antiretroviral use were not consistent. Some outcomes of dynamic models were based on unfeasible assumptions, such as no consideration of drug resistance, behavior disinhibition, or economic inputs in poor countries, and unrealistic input variables, for example, overstated initiation time, adherence, coverage, and efficacy of treatment. This paper reviewed dynamic mathematical models to ascertain the complex effects of ART on HIV transmission. This review discusses more conservative inputs and outcomes relative to antiretroviral use in HIV infections in dynamic mathematical models. ART alone cannot eliminate HIV transmission.

Modeling the implementation of universal coverage for HIV treatment as prevention and its impact on the HIV epidemic

The Joint United Nations Programme on HIV/AIDS (UNAIDS) recently updated its global targets for antiretroviral therapy (ART) coverage for HIV-positive persons under which 90 % of HIV-positive people are tested, 90 % of those are on ART, and 90 % of those achieve viral suppression. Treatment policy is moving toward treating all HIV-infected persons regardless of CD4 cell count-otherwise known as treatment as prevention-in order to realize the full therapeutic and preventive benefits of ART. Mathematical models have played an important role in guiding the development of these policies by projecting long-term health impacts and cost-effectiveness. To guide future policy, new mathematical models must consider the barriers patients face in receiving and taking ART. Here, we describe the HIV care cascade and ART delivery supply chain to examine how mathematical modeling can provide insight into cost-effective strategies for scaling-up ART coverage in sub-Saharan Africa and help achieve universal ART coverage.

Initiation of antiretroviral therapy and viral suppression after home HIV testing and counselling in KwaZulu-Natal, South Africa, and Mbarara district, Uganda: a prospective, observational intervention study

OBJECTIVE

Antiretroviral therapy (ART) significantly decreases HIV-associated morbidity, mortality, and HIV transmission through HIV viral load suppression. In high HIV prevalence settings, outreach strategies are needed to find asymptomatic HIV positive persons, link them to HIV care and ART, and achieve viral suppression.

METHODS

We conducted a prospective intervention study in two rural communities in KwaZulu-Natal, South Africa, and Mbabara district, Uganda. The intervention included home HIV testing and counseling (HTC), point-of-care CD4 count testing for HIV positive persons, referral to care, and one month then quarterly lay counselor follow-up visits. The outcomes at 12 months were linkage to care, and ART initiation and viral suppression among HIV positive persons eligible for ART (CD4≤350 cells/μL).

FINDINGS

3,393 adults were tested for HIV (96% coverage), of whom 635 (19%) were HIV positive. At baseline, 36% of HIV positive persons were newly identified (64% were previously known to be HIV positive) and 40% were taking ART. By month 12, 619 (97%) of HIV positive persons visited an HIV clinic, and of 123 ART eligible participants, 94 (76%) initiated ART by 12 months. Of the 77 participants on ART by month 9, 59 (77%) achieved viral suppression by month 12. Among all HIV positive persons, the proportion with viral suppression (<1,000 copies/mL) increased from 50% to 65% (p=<0.001) at 12 months.

INTERPRETATION

Community-based HTC in rural South Africa and Uganda achieved high testing coverage and linkage to care. Among those eligible for ART, a high proportion initiated ART and achieved viral suppression, indicating high adherence. Implementation of this HTC approach by existing community health workers in Africa should be evaluated to determine effectiveness and costs.

Growth patterns and scaling laws governing AIDS epidemic in Brazilian cities

Brazil holds approximately 1/3 of population living infected with AIDS (acquired immunodeficiency syndrome) in Central and South Americas, and it was also the first developing country to implement a large-scale control and intervention program against AIDS epidemic. In this scenario, we investigate the temporal evolution and current status of the AIDS epidemic in Brazil. Specifically, we analyze records of annual absolute frequency of cases for more than 5000 cities for the first 33 years of the infection in Brazil. We found that (i) the annual absolute frequencies exhibit a logistic-type growth with an exponential regime in the first few years of the AIDS spreading; (ii) the actual reproduction number decaying as a power law; (iii) the distribution of the annual absolute frequencies among cities decays with a power law behavior; (iv) the annual absolute frequencies and the number of inhabitants have an allometric relationship; (v) the temporal evolution of the annual absolute frequencies have different profile depending on the average annual absolute frequencies in the cities. These findings yield a general quantitative description of the AIDS infection dynamics in Brazil since the beginning. They also provide clues about the effectiveness of treatment and control programs against the infection, that has had a different impact depending on the number of inhabitants of cities. In this framework, our results give insights into the overall dynamics of AIDS epidemic, which may contribute to select empirically accurate models.

Evaluating social outcomes of HIV/AIDS interventions: a critical assessment of contemporary indicator frameworks

Introduction

Contemporary HIV-related theory and policy emphasize the importance of addressing the social drivers of HIV risk and vulnerability for a long-term response. Consequently, increasing attention is being given to social and structural interventions, and to social outcomes of HIV interventions. Appropriate indicators for social outcomes are needed in order to institutionalize the commitment to addressing social outcomes. This paper critically assesses the current state of social indicators within international HIV/AIDS monitoring and evaluation frameworks.

Methods

We analyzed the indicator frameworks of six international organizations involved in efforts to improve and synchronize the monitoring and evaluation of the HIV/AIDS response. Our analysis classifies the 328 unique indicators according to what they measure and assesses the degree to which they offer comprehensive measurement across three dimensions: domains of the social context, levels of change and organizational capacity.

Results and discussion

The majority of indicators focus on individual-level (clinical and behavioural) interventions and outcomes, neglecting structural interventions, community interventions and social outcomes (e.g. stigma reduction; community capacity building; policy-maker sensitization). The main tool used to address social aspects of HIV/AIDS is the disaggregation of data by social group. This raises three main limitations. Indicator frameworks do not provide comprehensive coverage of the diverse social drivers of the epidemic, particularly neglecting criminalization, stigma, discrimination and gender norms. There is a dearth of indicators for evaluating the social impacts of HIV interventions. Indicators of organizational capacity focus on capacity to effectively deliver and manage clinical services, neglecting capacity to respond appropriately and sustainably to complex social contexts.

Conclusions

Current indicator frameworks cannot adequately assess the social outcomes of HIV interventions. This limits knowledge about social drivers and inhibits the institutionalization of social approaches within the HIV/AIDS response. We conclude that indicator frameworks should expand to offer a more comprehensive range of social indicators for monitoring and evaluation and to include indicators of organizational capacity to tackle social drivers. While such expansion poses challenges for standardization and coordination, we argue that the complexity of interventions producing social outcomes necessitates capacity for flexibility and local tailoring in monitoring and evaluation.

'Getting to zero' in Asia and the Pacific through more strategic use of antiretrovirals for HIV prevention

Encouraged by experimental trials demonstrating the efficacy of antiretrovirals (ARVs) in preventing HIV infection, countries across the Asia-Pacific region have committed to the achievement of ambitious targets tantamount to ending AIDS. The available data suggest that some countries still can make progress through targeted condom promotion and the expansion of harm-reduction interventions, but that none may realise its vision of ‘zero new HIV infections’ without more strategic use of ARVs as part of a combination of HIV prevention efforts targeting key populations. Low rates of HIV testing among men who have sex with men, people who inject drugs, sex workers and other key populations evidence low treatment coverage where treatment could have the greatest impact on curbing local epidemics. Studies have demonstrated the promise of adding ARV treatment and pre-exposure prophylaxis to the existing HIV prevention toolkit, but achieving population-level impact will require service-delivery approaches that overcome traditional prevention, care and treatment program distinctions. Priorities include: (1) innovative strategies to reach, test, treat and retain in services the individuals most likely to acquire or transmit HIV; (2) task shifting and enhanced partnerships between the public sector and civil society; (3) improved ‘cascade’ data systems to assess and promote service uptake and retention; and (4) policy and financing reform to enhance HIV testing and treatment access among key populations.

How much demand for New HIV prevention technologies can we really expect? Results from a discrete choice experiment in South Africa

Background

For the first time in the history of HIV, new bio-medical interventions have been shown to be effective in preventing HIV transmission. For these new HIV prevention technologies (NPTs) to have an impact on the epidemic, they must be widely used. This study uses a discrete choice experiment (DCE) to: understand the relative strength of women’s preferences for product characteristics, understand the implications for substitution away from male condoms, and inform realistic modelling of their potential impact and cost-effectiveness.

Methods

A DCE was conducted among 1017 women in urban South Africa. Women were presented with choices between potential women’s NPTs (microbicides, diaphragm, female condom) and ‘what I did last time’ (use or not use a condom) with different HIV and pregnancy prevention effectiveness’ and prices. Choice probabilities are estimated using the nested logit model and used to predict uptake.

Results

In this high HIV prevalence setting, HIV prevention effectiveness is the main driver of uptake followed by pregnancy prevention effectiveness. For example a microbicide with poor effectiveness would have niche appeal at just 11% predicted uptake, while a highly effective microbicide (95% effective against HIV and pregnancy) would have far wider appeal (56% predicted uptake). Though women who reported not using condoms were more likely to choose the NPTs, at current very high rates of male condom use in South Africa (60%), about half of microbicide uptake is projected to be among those currently not using condoms.

Conclusions

Women are very interested in NPTs, especially if highly effective in preventing HIV and pregnancy. Women in greatest need were also most likely to switch to the new products. Where products are not yet available for distribution, proxy data, such as that generated by DCEs, can bring realism to overly optimistic uptake scenarios found in many current impact models.

Antiretroviral therapy for prevention of HIV transmission: implications for Europe

The aim of this review is to summarise the evidence on the population-level effect of antiretroviral therapy (ART) in preventing HIV infections, and to discuss potential implications in the European context of recommending starting ART when the CD4 count is above 350 cells/mm3. The ability of ART to reduce the risk of HIV transmission has been reported in observational studies and in a randomised controlled trial (HPTN 052), in which ART initiation reduced HIV transmission by 96% within serodiscordant couples. As yet, there is no direct evidence for such an effect among men having sex with men or people who inject drugs. HPTN 052 led international organisations to develop recommendations with a higher CD4 threshold for ART initiation. However, there remains a lack of strong evidence of clinical benefit for HIV-positive individuals starting ART with CD4 count above 350 cells/mm3. The main goal of ART provision should be to increase ART coverage for all those in need, based on the current guidelines, and the offer of ART to those who wish to reduce infectivity; increased HIV testing is therefore a key requirement. Other proven prevention means such as condom use and harm reduction for people who inject drugs remain critical.

High HIV testing uptake and linkage to care in a novel program of home-based HIV counseling and testing with facilitated referral in KwaZulu-Natal, South Africa

OBJECTIVE

For antiretroviral therapy (ART) to have a population-level HIV prevention impact, high levels of HIV testing and effective linkages to HIV care among HIV-infected persons are required.

METHODS

We piloted home-based counseling and testing (HBCT) with point-of-care CD4 count testing and follow-up visits to facilitate linkage of HIV-infected persons to local HIV clinics and uptake of ART in rural KwaZulu-Natal, South Africa. Lay counselor follow-up visits at months one, three and six evaluated the primary outcome of linkage to care. Plasma viral load was measured at baseline and month six.

RESULTS

671 adults were tested for HIV (91% coverage) and 201 (30%) were HIV-infected, of which 73 (36%) were new diagnoses. By month three, 90% of HIV-infected persons not on ART at baseline had visited an HIV clinic and 80% of those eligible for ART at baseline by South African guidelines (CD4≤200 cells/μL at the time of the study) had initiated ART. Among HIV-infected participants who were eligible for ART at baseline, mean viral load decreased by 3.23 log10 copies/mL (p<0.001) and the proportion with viral load suppression increased from 20% to 80% between baseline and month six.

CONCLUSIONS

In this pilot of HBCT and linkages to care in KwaZulu-Natal, 91% of adults were tested for HIV. Linkage to care was ∼90% both among newly-identified HIV-infected persons as well as known HIVinfected persons who were not engaged in care. Among those eligible for ART, a high proportion initiated ART and achieved viral suppression, indicating high adherence and reduced infectiousness.

Integrated strategies for combination HIV prevention: principles and examples for men who have sex with men in the Americas and heterosexual African populations

Combination HIV prevention is of high priority for increasing the impact of partially efficacious HIV prevention interventions for specific populations and settings. Developing the package requires critical review of local epidemiology of HIV infection regarding most-impacted populations and those at high risk of HIV transmission and acquisition, drivers of HIV infection, and available interventions to address these risk factors. Interventions should be considered in terms of the evidence basis for efficacy, potential synergies, and feasibility of delivery at scale, which is important to achieve high coverage and impact, coupled with high acceptability to populations, which will impact uptake, adherence, and retention. Evaluation requires process measures of uptake, adherence, retention, and outcome measures of reduction in HIV infectiousness and acquisition. Three examples of combination prevention concepts are summarized for men who have sex with men in the Americas, young women in sub-Saharan Africa, and HIV serodiscordant couples.