Antiretroviral therapy in prevention of HIV and TB: update on current research efforts

Promoting HIV care continuum outcomes among people who use drugs and alcohol: a systematic review of randomized trials evaluating behavioral HIV care interventions published from 2011 to 2023

BACKGROUND

Substance use remains a robust predictor of HIV infection and a serious impediment to HIV care continuum progression for people living with HIV. The primary research question of this systematic review is focused on understanding the extent to which behavioral HIV care interventions have been efficacious in helping people who live with HIV and who use substances along the HIV care continuum.

METHODS

Using PubMed and ProQuest databases, we performed a systematic review of randomized trials of behavioral HIV care continuum interventions among people who use substances published from 2011 to August 2023, since the beginning of the treatment-as-prevention era.

RESULTS

We identified 11 studies (total participants: N = 5635), ten intentionally targeting substance-using populations. Four studies involved samples using ≥ 1 substance (e.g., alcohol, opioids, stimulants, marijuana); four involved injection drug use; one involved methamphetamine use; and one involved alcohol use. One study targeted a population with incidental substance use (i.e., alcohol, injection drug use, non-injection drug use reported in most participants). Each study defined one or more HIV care outcomes of interest. Viral suppression was an outcome targeted in 9/11 studies, followed by uptake of antiretroviral therapy (ART; 7/11), ART adherence (6/11), retention in care (5/11), and linkage to care (3/11). While most (nine) of the studies found significant effects on at least one HIV care outcome, findings were mostly mixed. Mediated (2/11) and moderated (2/11) effects were minimally examined.

CONCLUSIONS

The results from this systematic review demonstrate mixed findings concerning the efficacy of previous HIV care interventions to improve HIV care continuum outcomes among people who use substances. However, heterogeneity of study components (e.g., diversity of substances used/assessed, self-report vs. objective measures, attrition) prevent broad deductions or conclusions about the amenability of specific substance-using populations to HIV care intervention. More coordinated, comprehensive, and targeted efforts are needed to promote and disentangle intervention effects on HIV care continuum outcomes among substance-using populations.

Half-life time prediction of developing first-line antiretroviral treatment failure and its risk factors among TB and HIV co-infected children in Northwest Ethiopia; multi setting historical follow-up study

BACKGROUND

Even though treatment failure is higher among TB and HIV infected children in a resource-limited setting, there is no prior evidence in general and in the study area in particular. Hence, this study was aimed at determining the half-life time prediction of developing first-line antiretroviral treatment failure and its risk factors among TB and HIV co-infected children.

METHODS

A historical follow-up study was employed among 239 TB and HIV co-infected children from January 2010-December 2020. The data was entered into Epi data version 4.2.2 and exported to STATA 14.0 Software for analysis. The Kaplan-Meier plot was used to estimate the half-life time to develop treatment failure. The required assumption was fulfilled for each predictor variable. Additionally, those variables having a p-value ≤0.25 in the bivariable analysis were fitted into a multivariable Cox-proportional hazards regression model. P-value, < 0.05 was used to declare a significant association.

RESULTS

A total of 239 TB and HIV co-infected children were involved in this study. The overall half-life time to develop first treatment failure was found to be 101 months, with a total of 1027.8 years' follow-up period. The incidence rate and proportion of developing first-line treatment failure were 5.5 per 100 PPY (Person-Year) [CI (confidence interval): 3.7, 6.9] 100 PPY and 23.8% (CI; 18.8, 29.7) respectively. Factors such as hemoglobin 10 mg/dl [AHR (Adjusted Hazard Ratio): 3.2 (95% CI: 1.30, 7.73), severe acute malnutrition [AHR: 3.8 (95% CI: 1.51, 79.65), World Health Organization stage IV [AHR: 2.4 (95% CI: 1.15, 4.93)], and cotrimoxazole prophylaxis non user [AHR: 2.3 (95% CI: 1.14, 4.47)] were found to be a risk factor to develop treatment failure.

CONCLUSION

In this study, the half-life time to develop first-line treatment failure was found to be very low. In addition, the incidence was found to be very high. The presence of hemoglobin 10 mg/dl, severe acute malnutrition, World Health Organization stage, and non-use of cotrimoxazole prophylaxis were discovered to be risk factors for treatment failure. Further prospective cohort and qualitative studies should be conducted to improve the quality of care in paediatric ART clinics to reduce the incidence or burden of first line treatment failure among TB and HIV co-infected children.

Transmitted drug resistance to Tenofovir/Emtricitabine among persons with newly diagnosed HIV infection in Shenyang city, Northeast China from 2016 to 2018

BACKGROUND

To assess transmitted drug resistance (TDR) to tenofovir (TDF)/emtricitabine (FTC), using as pre-exposure prophylaxis, among newly diagnosed human immunodeficiency virus-1 (HIV-1)-infected residents in Shenyang city, northeast China.

METHODS

Demographic and epidemiological information of all newly diagnosed HIV-1 infected residents in Shenyang city from 2016 to 2018 were anonymously collected from the local HIV epidemic database. HIV-1 pol sequences were amplified from RNA in cryopreserved plasma samples and sequenced directly. Viral subtypes were inferred with phylogenetic analysis and drug resistance mutations (DRMs) were determined according to the Stanford HIVdb algorithm. Recent HIV infection was determined with HIV Limiting Antigen avidity electro immunoassay.

RESULTS

A total of 2176 sequences (92.4%, 2176/2354) were obtained; 70.9% (1536/2167) were CRF01_AE, followed by CRF07_BC (18.0%, 391/2167), subtype B (4.7%, 102/2167), other subtypes (2.6%, 56/2167), and unique recombinant forms (3.8%, 82/2167). The prevalence of TDR was 4.9% (107/2167), among which, only 0.6% (13/2167) was resistance to TDF/FTC. Most of these subjects had CRF01_AE strains (76.9%, 10/13), were unmarried (76.9%, 10/13), infected through homosexual contact (92.3%, 12/13), and over 30 years old (median age: 33). The TDF/FTC DRMs included K65R (8/13), M184I/V (5/13), and Y115F (2/13). Recent HIV infection accounted for only 23.1% (3/13). Most cases were sporadic in the phylogenetic tree, except two CRF01_AE sequences with K65R (Bootstrap value: 99%).

CONCLUSIONS

The prevalence of TDR to TDF/FTC is low among newly diagnosed HIV-infected cases in Shenyang, suggesting that TDR may have little impact on the protective effect of the ongoing CROPrEP project in Shenyang city.

Prisoners' access to HIV services in southern Malawi: a cross-sectional mixed methods study

BACKGROUND

The prevalence of Human Immunodeficiency Virus (HIV) among prisoners remains high in many countries, especially in Africa, despite a global decrease in HIV incidence. Programs to reach incarcerated populations with HIV services have been implemented in Malawi, but the success of these initiatives is uncertain. We explored which challenges prisoners face in receiving essential HIV services and whether HIV risk behavior is prevalent in prisons.

METHODS

We conducted a mixed-methods (qualitative and quantitative), cross-sectional study in 2018 in six prisons in Southern Malawi, two large central prisons with on-site, non-governmental organization (NGO) supported clinics and 4 smaller rural prisons. Four hundred twelve prisoners were randomly selected and completed a structured questionnaire. We conducted in-depth interviews with 39 prisoners living with HIV, which we recorded, transcribed and translated. We used descriptive statistics and logistic regression to analyze quantitative data and content analysis for qualitative data.

RESULTS

The majority of prisoners (93.2%) were male, 61.4% were married and 63.1% were incarcerated for 1-5 years. Comprehensive services were reported to be available in the two large, urban prisons. Female prisoners reported having less access to general medical services than males. HIV risk behavior was reported infrequently and was associated with incarceration in urban prisons (adjusted odds ratio [aOR] 18.43; 95% confidence interval [95%-CI] 7.59-44.74; p = < 0.001) and not being married (aOR 17.71; 95%-CI 6.95-45.13; p = < 0.001). In-depth interviews revealed that prisoners living with HIV experienced delays in referrals for more severe illnesses. Prisoners emphasized the detrimental impact of poor living conditions on their personal health and their ability to adhere to antiretroviral therapy (ART).

CONCLUSIONS

Malawian prisoners reported adequate knowledge about HIV services albeit with gaps in specific areas. Prisoners from smaller, rural prisons had suboptimal access to comprehensive HIV services and female prisoners reported having less access to health care than males. Prisoners have great concern about their poor living conditions affecting general health and adherence to ART. These findings provide guidance for improvement of HIV services and general health care in Malawian institutionalized populations such as prisoners.

Novel community health worker strategy for HIV service engagement in a hyperendemic community in Rakai, Uganda: A pragmatic, cluster-randomized trial

BACKGROUND

Effective implementation strategies are needed to increase engagement in HIV services in hyperendemic settings. We conducted a pragmatic cluster-randomized trial in a high-risk, highly mobile fishing community (HIV prevalence: approximately 38%) in Rakai, Uganda, to assess the impact of a community health worker-delivered, theory-based (situated Information, Motivation, and Behavior Skills), motivational interviewing-informed, and mobile phone application-supported counseling strategy called "Health Scouts" to promote engagement in HIV treatment and prevention services.

METHODS AND FINDINGS

The study community was divided into 40 contiguous, randomly allocated clusters (20 intervention clusters, n = 1,054 participants at baseline; 20 control clusters, n = 1,094 participants at baseline). From September 2015 to December 2018, the Health Scouts were deployed in intervention clusters. Community-wide, cross-sectional surveys of consenting 15 to 49-year-old residents were conducted at approximately 15 months (mid-study) and at approximately 39 months (end-study) assessing the primary programmatic outcomes of self-reported linkage to HIV care, antiretroviral therapy (ART) use, and male circumcision, and the primary biologic outcome of HIV viral suppression (<400 copies/mL). Secondary outcomes included HIV testing coverage, HIV incidence, and consistent condom use. The primary intent-to-treat analysis used log-linear binomial regression with generalized estimating equation to estimate prevalence risk ratios (PRR) in the intervention versus control arm. A total of 2,533 (45% female, mean age: 31 years) and 1,903 (46% female; mean age 32 years) residents completed the mid-study and end-study surveys, respectively. At mid-study, there were no differences in outcomes between arms. At end-study, self-reported receipt of the Health Scouts intervention was 38% in the intervention arm and 23% in the control arm, suggesting moderate intervention uptake in the intervention arm and substantial contamination in the control arm. At end-study, intention-to-treat analysis found higher HIV care coverage (PRR: 1.06, 95% CI: 1.01 to 1.10, p = 0.011) and ART coverage (PRR: 1.05, 95% CI: 1.01 to 1.10, p = 0.028) among HIV-positive participants in the intervention compared with the control arm. Male circumcision coverage among all men (PRR: 1.05, 95% CI: 0.96 to 1.14, p = 0.31) and HIV viral suppression among HIV-positive participants (PRR: 1.04, 95% CI: 0.98 to 1.12, p = 0.20) were higher in the intervention arm, but differences were not statistically significant. No differences were seen in secondary outcomes. Study limitations include reliance on self-report for programmatic outcomes and substantial contamination which may have diluted estimates of effect.

CONCLUSIONS

A novel community health worker intervention improved HIV care and ART coverage in an HIV hyperendemic setting but did not clearly improve male circumcision coverage or HIV viral suppression. This community-based, implementation strategy may be a useful component in some settings for HIV epidemic control.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02556957.

'Then her neighbour will not know her status': how health providers advocate antiretroviral therapy under universal test and treat

Introduction

Universal test and treat (UTT)-antiretroviral therapy (ART) for all HIV-positive individuals regardless of CD4 count-is the WHO's recommended treatment guideline. UTT has implications for health providers' workload in areas of high HIV prevalence and for understandings of ART and HIV. This article explores health providers' experiences of implementing UTT in Hhohho Region, Eswatini.

Methods

Between March 2015 and October 2016, in-depth interviews were conducted with health providers implementing UTT. Interviews were transcribed verbatim and translated into English for qualitative content analysis.

Results

Twenty-five providers from eight facilities were interviewed. Respondents encouraged early ART by promoting its overall health benefits, and the possibility of avoiding disclosure and HIV-related stigma in the community. Some health providers downplayed UTT's preventive benefits to avoid discouraging condom use. Respondents suggested that initiating ART immediately after testing could improve linkage-to-care, but recognized that overly hasty initiation might affect adherence. Viral load testing was seen as a potentially useful tool to monitor clients' response to ART.

Conclusions

Health providers appropriated stigma to encourage early ART. This suggests an attentiveness to the social burden of HIV/AIDS, but potentially exacerbates discrimination and conflicts with efforts to reduce HIV-related stigma.

False starts in 'test and start': a qualitative study of reasons for delayed antiretroviral therapy in Swaziland

Background

Test and start, antiretroviral therapy (ART) for all HIV-positive individuals, is a WHO-recommended treatment guideline. In Swaziland, test and start has been evaluated through the MaxART implementation study. This article examines why, in MaxART, some newly diagnosed HIV-positive clients delayed initiating ART.

Methods

Thirteen HIV-positive clients who delayed ART for ≥90 d after testing were identified from the MaxART study database and interviewed. Interviews were audio recorded, transcribed and translated into English for qualitative content analysis.

Results

Respondents had often tested positive several times before initiating ART, with the initial diagnosis sometimes completely unexpected. Repeat testing-and delayed ART-was linked to a desire to come to terms with their diagnosis and prepare for a lifelong treatment course. Clients previously enrolled in pre-ART, particularly with high CD4 counts, had internalized past messages about ART as being non-essential and taking care of oneself through other means. Concerns about ART-related adverse events were weighed against these messages. Worries about inadvertent disclosure and its impact on social and economic relationships also discouraged initiation.

Conclusion

Although potentially reducing logistical barriers, expedited ART initiation does not necessarily accommodate some clients' need for time to come to terms with the diagnosis and the prospect of lifelong treatment.

Redemption of the "spoiled identity:" the role of HIV-positive individuals in HIV care cascade interventions

Introduction

The concept of “therapeutic citizenship” has drawn attention to ways in which public testimony, the “story‐telling in the public sphere” undertaken by people living with HIV (PLHIV), has shaped the global response to the epidemic. This paper presents qualitative findings from two large studies in eastern Africa that reveal how the advent of population‐based HIV testing campaigns and efforts to accelerate antiretroviral “treatment for all” has precipitated a rapidly expanding therapeutic citizenship “project,” or social movement. The title of this paper refers to Goffman's original conceptualization of stigma as a social process through which a person's identity is rendered “spoiled.”

Methods

Data were derived from qualitative studies embedded within two clinical trials, Sustainable East African Research in Community Health (SEARCH) (NCT# 01864603) in Kenya and Uganda, and START‐ART (NCT# 01810289) in Uganda, which aimed to offer insights into the pathways through which outcomes across the HIV care continuum can be achieved by interventions deployed in the studies, any unanticipated consequences, and factors that influenced implementation. Qualitative in‐depth semi‐structured interviews were conducted among cohorts of adults in 2014 through 2015; across both studies and time periods, 217 interviews were conducted with 166 individuals. Theoretically informed, team‐based analytic approaches were used for the analyses.

Results

Narratives from PLHIV, who have not always been conceptualized as actors but rather usually as targets of HIV interventions, revealed strongly emergent themes related to these individuals' use of HIV biomedical resources and discourses to fashion a new, empowered subjecthood. Experiencing the benefits of antiretroviral therapy (ART) emboldens many individuals to transform their “spoiled” identities to attain new, valorized identities as “advocates for ART” in their communities. We propose that the personal revelation of what some refer to as the “gospel of ARVs,” the telling of personal stories about HIV in the public sphere and actions to accompany other PLHIV on their journey into care, is driven by its power to redeem the “spoiled identity:” it permits PLHIV to overcome self‐stigma and regain full personhood within their communities.

Conclusions

PLHIV are playing an unanticipated but vital role in the successful implementation of HIV care cascade interventions.

Effect of isoniazid preventive therapy on risk of death in west African, HIV-infected adults with high CD4 cell counts: long-term follow-up of the Temprano ANRS 12136 trial

BACKGROUND

Temprano ANRS 12136 was a factorial 2 × 2 trial that assessed the benefits of early antiretroviral therapy (ART; ie, in patients who had not reached the CD4 cell count threshold used to recommend starting ART, as per the WHO guidelines that were the standard during the study period) and 6-month isoniazid preventive therapy (IPT) in HIV-infected adults in Côte d'Ivoire. Early ART and IPT were shown to independently reduce the risk of severe morbidity at 30 months. Here, we present the efficacy of IPT in reducing mortality from the long-term follow-up of Temprano.

METHODS

For Temprano, participants were randomly assigned to four groups (deferred ART, deferred ART plus IPT, early ART, or early ART plus IPT). Participants who completed the trial follow-up were invited to participate in a post-trial phase. The primary post-trial phase endpoint was death, as analysed by the intention-to-treat principle. We used Cox proportional models to compare all-cause mortality between the IPT and no IPT strategies from inclusion in Temprano to the end of the follow-up period.

FINDINGS

Between March 18, 2008, and Jan 5, 2015, 2056 patients (mean baseline CD4 count 477 cells per μL) were followed up for 9404 patient-years (Temprano 4757; post-trial phase 4647). The median follow-up time was 4·9 years (IQR 3·3-5·8). 86 deaths were recorded (Temprano 47 deaths; post-trial phase 39 deaths), of which 34 were in patients randomly assigned IPT (6-year probability 4·1%, 95% CI 2·9-5·7) and 52 were in those randomly assigned no IPT (6·9%, 5·1-9·2). The hazard ratio of death in patients who had IPT compared with those who did not have IPT was 0·63 (95% CI, 0·41 to 0·97) after adjusting for the ART strategy (early vs deferred), and 0·61 (0·39-0·94) after adjustment for the ART strategy, baseline CD4 cell count, and other key characteristics. There was no evidence for statistical interaction between IPT and ART (p_interaction=0·77) or between IPT and time (p_interaction=0·94) on mortality.

INTERPRETATION

In Côte d'Ivoire, where the incidence of tuberculosis was last reported as 159 per 100 000 people, 6 months of IPT has a durable protective effect in reducing mortality in HIV-infected people, even in people with high CD4 cell counts and who have started ART.

FUNDING

National Research Agency on AIDS and Viral Hepatitis (ANRS).

Incidence of Tuberculosis Among HIV-Positive Individuals Initiating Antiretroviral Treatment at Higher CD4 Counts in the HPTN 071 (PopART) Trial in South Africa

INTRODUCTION

Antiretroviral treatment (ART) guidelines recommend life-long ART for all HIV-positive individuals. This study evaluated tuberculosis (TB) incidence on ART in a cohort of HIV-positive individuals starting ART regardless of CD4 count in a programmatic setting at 3 clinics included in the HPTN 071 (PopART) trial in South Africa.

METHODS

A retrospective cohort analysis of HIV-positive individuals aged ≥18 years starting ART, between January 2014 and November 2015, was conducted. Follow-up was continued until 30 May 2016 or censored on the date of (1) incident TB, (2) loss to follow-up from HIV care or death, or (3) elective transfer out; whichever occurred first.

RESULTS

The study included 2423 individuals. Median baseline CD4 count was 328 cells/μL (interquartile range 195-468); TB incidence rate was 4.41/100 person-years (95% confidence interval [CI]: 3.62 to 5.39). The adjusted hazard ratio of incident TB was 0.27 (95% CI: 0.12 to 0.62) when comparing individuals with baseline CD4 >500 and ≤500 cells/μL. Among individuals with baseline CD4 count >500 cells/μL, there were no incident TB cases in the first 3 months of follow-up. Adjusted hazard of incident TB was also higher among men (adjusted hazard ratio 2.16; 95% CI: 1.41 to 3.30).

CONCLUSIONS

TB incidence after ART initiation was significantly lower among individuals starting ART at CD4 counts above 500 cells/μL. Scale-up of ART, regardless of CD4 count, has the potential to significantly reduce TB incidence among HIV-positive individuals. However, this needs to be combined with strengthening of other TB prevention strategies that target both HIV-positive and HIV-negative individuals.

Impact of a community health worker HIV treatment and prevention intervention in an HIV hotspot fishing community in Rakai, Uganda (mLAKE): study protocol for a randomized controlled trial

Background

Effective yet practical strategies are needed to increase engagement in HIV treatment and prevention services, particularly in high-HIV-prevalence hotspots. We designed a community-based intervention called “Health Scouts” to promote uptake and adherence to HIV services in a highly HIV-prevalent fishing community in Rakai, Uganda. Using a situated Information, Motivation, and Behavioral skills theory framework, the intervention consists of community health workers, called Health Scouts, who use motivational interviewing strategies and mobile health tools to promote engagement in HIV treatment and prevention services.

Methods/design

The Health Scout intervention is being evaluated through a pragmatic, parallel, cluster-randomized controlled trial with an allocation ratio of 1:1. The study setting is a single high-HIV-prevalence fishing community in Rakai, Uganda divided into 40 contiguous neighborhood clusters each containing about 65 households. Twenty clusters received the Health Scout Intervention; 20 clusters received standard of care. The Health Scout intervention is delivered within the community at the household level, targeting all residents aged 15 years or older. The primary programmatic outcomes are self-reported HIV care, antiretroviral therapy, and male circumcision coverage; the primary biologic outcome is population-level HIV viremia prevalence. Follow-up is planned for about 3 years.

Discussion

HIV treatment and prevention service engagement remains suboptimal in HIV hotspots. New, community-based implementation approaches are needed. If found to be effective in this trial, the Health Scout intervention may be an important component of a comprehensive HIV response.

Trial registration

ClinicalTrials.gov, ID: NCT02556957. Registered on 20 September 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2243-6) contains supplementary material, which is available to authorized users.

Access for all: contextualising HIV treatment as prevention in Swaziland

This article explores how notions of the individual and population are evoked in two ongoing HIV treatment as prevention (TasP) implementation studies in Swaziland. By contrasting policy discourses with lived kinship experiences of people living with HIV, we seek to understand how TasP unfolds in the Swazi context. Data collection consisted of eight focus group discussions with people living with HIV who were members of support groups to examine their perspectives about TasP. In addition, 18 key informant interviews were conducted with study team members, national-level policy-makers and NGO representatives involved in the design of health communication messages about TasP in Swaziland. Thematic analysis was used to identify recurrent themes in transcripts and field notes. Policy-makers and people living with HIV actively resisted framing HIV treatment as a prevention technology but promoted it as (earlier) access to treatment for all. TasP was not conceptualised in terms of individual or societal benefits, which are characteristic of international public health debates; rather its locally situated meanings were embedded in kinship experiences, concerns about taking responsibility for one's own health and others, local biomedical knowledge about drug resistance, and secrecy. The findings from this study suggest that more attention is needed to understand how the global discourse of TasP becomes shaped in practice in different cultural contexts.

Traditional health practitioners' management of HIV/AIDS in rural South Africa in the era of widespread antiretroviral therapy

BACKGROUND

Traditional health practitioners (THPs) have been identified as a key local resource in the fight against human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) in South Africa. However, their approaches to the treatment of people living with HIV (PLHIV) have been met with scepticism by some biomedical practitioners amid increasing access to antiretroviral therapy (ART).

OBJECTIVE

In light of this ambivalence, this study aims to document and identify treatment approaches of THPs to the management of illness among PLHIV in the current era of widespread access to ART.

METHODS

The study was conducted as part of a larger trial of Treatment as Prevention (TasP) in rural northern Kwa-Zulu Natal, intended to treat PLHIV regardless of CD4 count. Nine THPs were enrolled using purposive and snowballing techniques. Repeat group discussions, triangulated with community walks and photovoice techniques, were conducted. A thematic analysis approach was used to analyse the data.

RESULTS

Eight of the nine THPs had received training in biomedical aspects of HIV. THPs showed a multilayered decision-making process in managing illness among PLHIV, influenced by the attributes and choices of the THPs. THPs assessed and managed illness among PLHIV based on THP training in HIV/AIDS, THP type, as well as knowledge and experience in the traditional healing practice. Management of illness depended on the patients' report of their HIV status or willingness to test for HIV.

CONCLUSIONS

THPs' approaches to illness in PLHIV appear to be shifting in light of increasing exposure to HIV/AIDS-related information. Importantly, disclosure of HIV status plays a major role in THPs' management of illness among PLHIV, as well as linkage to HIV testing and care for their patients. Therefore, THPs can potentially enhance the success of ART for PLHIV when HIV status is known.

Antiretroviral treatment regardless of CD4 count: the universal answer to a contextual question

After a period where it was recommended to start antiretroviral therapy (ART) early, the CD4 threshold for treating asymptomatic adults dropped to 200/mm³ at the beginning of the 2000s. This was mostly due to a great prudence with regards to drug toxicity. The ART-start CD4 threshold in most international guidelines was then raised to 350/mm³ in 2006–2009 and to 500/mm³ in 2009–2013. Between 2012 and 2015, international guidelines went the last step further and recommended treating all HIV-infected adults regardless of their CD4 count. This ultimate step was justified by the results of three randomized controlled trials, HPTN 052, Temprano ANRS 12136 and START. These three trials assessed the benefits and risks of starting ART immediately upon inclusion (“early ART”) versus deferring ART until the current starting criteria were met (“deferred ART”). Taken together, they recruited 8427 HIV-infected adults in 37 countries. The primary outcome was severe morbidity, a composite outcome that included all-cause deaths, AIDS diseases, and non-AIDS cancers in the three trials. The trial results were mutually consistent and reinforcing. The overall risk of severe morbidity was significantly 44–57 % lower in patients randomized to early ART as compared to deferred ART. Early ART also decreased the risk of AIDS, tuberculosis, invasive bacterial diseases and Kaposi’s sarcoma considered separately. The incidence of severe morbidity was 3.2 and 3.5 times as high in HPTN052 and Temprano as in START, respectively. This difference is mostly due to the geographical context of morbidity. The evidence is now strong that initiating ART at high CD4 counts entails individual benefits worldwide, and that this is all the more true in low resource contexts where tuberculosis and other bacterial diseases are highly prevalent. These benefits in addition to population benefits consisting of preventing HIV transmission demonstrated in HPTN052, justify the recommendation that HIV-infected persons should initiate ART regardless of CD4 count. This recommendation faces many challenges, including the fact that switching from “treat at 500 CD4/mm³” to “treat everyone” not only requires more tests and more drugs, but also more people to support patients and help them remain in care.

HIV Epidemic in Asia: Implications for HIV Vaccine and Other Prevention Trials

An overall decrease of HIV prevalence is now observed in several key Asian countries due to effective prevention programs. The decrease in HIV prevalence and incidence may further improve with the scale-up of combination prevention interventions. The implementation of future prevention trials then faces important challenges. The opportunity to identify heterosexual populations at high risk such as female sex workers may rapidly wane. With unabating HIV epidemics among men who have sex with men (MSM) and transgender (TG) populations, an effective vaccine would likely be the only option to turn the epidemic. It is more likely that efficacy trials will occur among MSM and TG because their higher HIV incidence permits smaller and less costly trials. The constantly evolving patterns of HIV-1 diversity in the region suggest close monitoring of the molecular HIV epidemic in potential target populations for HIV vaccine efficacy trials. CRF01_AE remains predominant in southeast Asian countries and MSM populations in China. This relatively steady pattern is conducive to regional efficacy trials, and as efficacy warrants, to regional licensure. While vaccines inducing nonneutralizing antibodies have promise against HIV acquisition, vaccines designed to induce broadly neutralizing antibodies and cell-mediated immune responses of greater breadth and depth in the mucosal compartments should be considered for testing in MSM and TG. The rationale and design of efficacy trials of combination prevention modalities such as HIV vaccine and preexposure prophylaxis (PrEP) remain hypothetical, require high adherence to PrEP, are more costly, and present new regulatory challenges. The prioritization of prevention interventions should be driven by the HIV epidemic and decided by the country-specific health and regulatory authorities. Modeling the impact and cost-benefit may help this decision process.

Optimizing an HIV testing program using a system dynamics model of the continuum of care

Realizing the full individual and population-wide benefits of antiretroviral therapy for human immunodeficiency virus (HIV) infection requires an efficient mechanism of HIV-related health service delivery. We developed a system dynamics model of the continuum of HIV care in Vancouver, Canada, which reflects key activities and decisions in the delivery of antiretroviral therapy, including HIV testing, linkage to care, and long-term retention in care and treatment. To measure the influence of operational interventions on population health outcomes, we incorporated an HIV transmission component into the model. We determined optimal resource allocations among targeted and routine testing programs to minimize new HIV infections over five years in Vancouver. Simulation scenarios assumed various constraints informed by the local health policy. The project was conducted in close collaboration with the local health care providers, Vancouver Coastal Health Authority and Providence Health Care.

Stakeholder Engagement in HIV Cure Research: Lessons Learned from Other HIV Interventions and the Way Forward

Clinical and basic science advances have raised considerable hope for achieving an HIV cure by accelerating research. This research is dominated primarily by issues about the nature and design of current and future clinical trials. Stakeholder engagement for HIV cure remains in its early stages. Our analysis examines timing and mechanisms of historical stakeholder engagement in other HIV research areas for HIV-uninfected individuals [vaccine development and pre-exposure prophylaxis (PrEP)], and HIV-infected individuals (treatment as prevention, prevention of mother-to-child transmission, and treatment of acute HIV infection) and articulate a plan for HIV cure stakeholder engagement. The experience from HIV vaccine development shows that early engagement of stakeholders helped manage expectations, mitigating the failure of several vaccine trials, while paving the way for subsequent trials. The relatively late engagement of HIV stakeholders in PrEP research may partly explain some of the implementation challenges. The treatment-related stakeholder engagement was strong and community-led from the onset and helped translation from research to implementation. We outline five steps to initiate and sustain stakeholder engagement in HIV cure research and conclude that stakeholder engagement represents a key investment in which stakeholders mutually agree to share knowledge, benefits, and risk of failure. Effective stakeholder engagement prevents misconceptions. As HIV cure research advances from early trials involving subjects with generally favorable prognosis to studies involving greater risk and uncertainty, success may depend on early and deliberate engagement of stakeholders.

Factors Associated with Timing of Initiation of Antiretroviral Therapy among HIV-1 Infected Adults in the Niger Delta Region of Nigeria

Introduction

Based on growing evidence mainly from countries outside Sub-Saharan Africa, the World Health Organisation (WHO) now recommends initiation of antiretroviral therapy (ART) in HIV-infected individuals in developing countries when CD4 cell count (CD4+) is ≤ 500cells/ul. Nigeria accounts for about 14% of the estimated HIV/AIDS burden in Sub-Saharan Africa. We evaluated the factors associated with timing of initiation of ART among treatment-ineligible HIV-infected adults from Nigeria.

Methods

We retrospectively reviewed the hospital records of ART ineligible HIV-infected adults who enrolled into HIV care between January 2008 and December 2012 at two major tertiary hospitals in Bayelsa State, South-South Nigeria. Demographic, clinical and laboratories data were obtained at presentation, at each subsequent visit at 6 monthly intervals and at time of initiation of ART. Cox proportional regression and Kaplan-Meier survival analysis were used to evaluate independent predictors of time to initiation of ART.

Results

Amongst the 280 study participants, 70.6% were females, 62.6% had CD4+ ≥500cells/ul, 48.4% had WHO HIV Stage 1 disease and 34.3% were lost to follow up. In a cohort of 180 participants followed up for ≥3months, participants with CD4+ of 351-500cells/ul and stage 2 disease were more likely to start ART earlier than those with CD4+ > 500cells/ul (Hazard ratio [HR]-1.7, 95% confidence interval [CI] of 1.0-2.9) and stage 1 disease (HR-2.3 (95% CI-1.3-4.2) respectively. HIV-infected adults with faster CD4+ decay required earlier ART initiation, especially in the first year of follow up.

Conclusion

ART-ineligible HIV-infected adults on follow up in South-South Nigeria are more likely to require earlier initiation of ART if they have stage 2 HIV disease or CD4+ ≤500cells/ul at presentation. Our findings suggest faster progression of HIV-disease in these groups of individuals and corroborate the growing evidence in support for earlier initiation of ART.

Adaptive pair-matching in randomized trials with unbiased and efficient effect estimation

In randomized trials, pair-matching is an intuitive design strategy to protect study validity and to potentially increase study power. In a common design, candidate units are identified, and their baseline characteristics used to create the best n/2 matched pairs. Within the resulting pairs, the intervention is randomized, and the outcomes measured at the end of follow-up. We consider this design to be adaptive, because the construction of the matched pairs depends on the baseline covariates of all candidate units. As a consequence, the observed data cannot be considered as n/2 independent, identically distributed pairs of units, as common practice assumes. Instead, the observed data consist of n dependent units. This paper explores the consequences of adaptive pair-matching in randomized trials for estimation of the average treatment effect, conditional the baseline covariates of the n study units. By avoiding estimation of the covariate distribution, estimators of this conditional effect will often be more precise than estimators of the marginal effect. We contrast the unadjusted estimator with targeted minimum loss based estimation and show substantial efficiency gains from matching and further gains with adjustment. This work is motivated by the Sustainable East Africa Research in Community Health study, an ongoing community randomized trial to evaluate the impact of immediate and streamlined antiretroviral therapy on HIV incidence in rural East Africa.

Costs of health resource utilization among HIV-positive individuals in British Columbia, Canada: results from a population-level study

BACKGROUND

Through delayed HIV disease progression, highly active antiretroviral therapy (HAART) may reduce direct medical costs, thus at least partially offsetting therapy costs. Recent findings regarding the secondary preventive benefits of HAART necessitate careful consideration of funding allocations for HIV/AIDS care. Our objective is to estimate non-HAART direct medical costs at different levels of disease progression and over time in British Columbia, Canada.

METHODS

We considered the population of individuals with HIV/AIDS within a set of linked disease registries and health administrative databases (N = 11,836) from 1996 to 2010. Costs of hospitalization, physician billing, diagnostic testing and non-HAART medications were calculated in 2010 Canadian dollars. Effects of covariates on quarterly costs were assessed with a two-part model with logit for probability of non-zero costs and a generalized linear model (GLM). Net effects of CD4 strata on direct non-HAART medical costs were evaluated over time during the study period.

RESULTS

Compared with person-quarters in which CD4 >500/mm(3), costs were Can$185 (95 % confidence interval [CI] 132-239) greater for CD4 350-500/mm(3), Can$441 (95 % CI 366-516) greater for CD4 200-350/mm(3) and Can$1,173 (95 % CI 1,051-1,294) greater when CD4 <200/mm(3). Prior to HIV care initiation, individuals incurred costs Can$385 (95 % CI 283-487) greater than in periods with CD4 >500/mm(3). Hospitalization comprised the majority of the increment in costs amongst those with no measured CD4. Evaluated at CD4 state conditional means, those with CD4 <200/mm(3) incurred quarterly costs of Can$5,781 (95 % CI 4,716-6,846) versus Can$1,307 (95 % CI 1,154-1,460; p < 0.001) for CD4 ≥500/mm(3) in 2010.

CONCLUSION

Non-HAART direct medical costs were substantially lower for individuals during periods of sustained virologic suppression and high CD4 count. HIV treatment and prevention evaluations require detailed health resource use data to inform funding allocation decisions.

[Study of human immunodeficiency virus transmission chains in Andalusia: analysis from baseline antiretroviral resistance sequences]

INTRODUCTION AND OBJECTIVE

Protease and reverse transcriptase HIV-1 sequences provide useful information for patient clinical management, as well as information on resistance to antiretrovirals. The aim of this study is to evaluate transmission events, transmitted drug resistance, and to georeference subtypes among newly diagnosed patients referred to our center.

METHODS

A study was conducted on 693 patients diagnosed between 2005 and 2012 in Southern Spain. Protease and reverse transcriptase sequences were obtained for resistance to cART analysis with Trugene(®) HIV Genotyping Kit (Siemens, NAD). MEGA 5.2, Neighbor-Joining, ArcGIS and REGA were used for subsequent analysis.

RESULTS

The results showed 298 patients clustered into 77 different transmission events. Most of the clusters were formed by pairs (n=49), of men having sex with men (n=26), Spanish (n=37), and below 45 years of age (73.5%). Urban areas from Granada, and the coastal areas of Almeria and Granada showed the greatest subtype heterogeneity. Five clusters were formed by more than 10 patients, and 15 clusters had transmitted drug resistance.

CONCLUSIONS

The study data demonstrate how the phylogenetic characterization of transmission clusters is a powerful tool to monitor the spread of HIV, and may contribute to design correct preventive measures to minimize it.

Global HIV epidemiology: A guide for strategies in prevention and care

Global trends in HIV incidence are estimated typically by serial prevalence surveys in selected sentinel populations or less often in representative population samples. Incidence estimates are often modeled because cohorts are costly to maintain and are rarely representative of larger populations. From global trends, we can see reason for cautious optimism. Downward trends in generalized epidemics in Africa, concentrated epidemics in persons who inject drugs (PWID), some female sex worker cohorts, and among older men who have sex with men (MSM) have been noted. However, younger MSM and those from minority populations, as with black MSM in the United States, show continued transmission at high rates. Among the many HIV prevention strategies, current efforts to expand testing, linkage to effective care, and adherence to antiretroviral therapy are known as "treatment as prevention" (TasP). A concept first forged for the prevention of mother to child transmission, TasP generates high hopes that persons treated early will derive considerable clinical benefits and that lower infectiousness will reduce transmission in communities. With the global successes of risk reduction for PWID, we have learned that reducing marginalization of the at-risk population, implementation of nonjudgmental and pragmatic sterile needle and syringe exchange programs, and offering of opiate substitution therapy to help persons eschew needle use altogether can work to reduce the HIV epidemic. Never has the urgency of stigma reduction and guarantees of human rights been more urgent; a public health approach to at-risk populations requires that to avail themselves of prevention services and they must feel welcomed.

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.

Antiretroviral adherence interventions in Southern Africa: implications for using HIV treatments for prevention

There is concern that the expansion of ART (antiretroviral treatment) programmes to incorporate the use of treatment as prevention (TasP) may be associated with low levels of adherence and retention in care, resulting in the increased spread of drug-resistant HIV. We review research published over the past year that reports on interventions to improve adherence and retention in care in Southern Africa, and discuss these in terms of their potential to support the expansion of ART programmes for TasP. We found eight articles published since January 2012, seven of which were from South Africa. The papers describe innovative models for ART care and adherence support, some of which have the potential to facilitate the ongoing scale- up of treatment programmes for increased coverage and TasP. The extent to which interventions from South Africa can be effectively implemented in other, lower-resource Southern African countries is unclear.

Why the proportion of transmission during early-stage HIV infection does not predict the long-term impact of treatment on HIV incidence

Antiretroviral therapy (ART) reduces the infectiousness of HIV-infected persons, but only after testing, linkage to care, and successful viral suppression. Thus, a large proportion of HIV transmission during a period of high infectiousness in the first few months after infection ("early transmission") is perceived as a threat to the impact of HIV "treatment-as-prevention" strategies. We created a mathematical model of a heterosexual HIV epidemic to investigate how the proportion of early transmission affects the impact of ART on reducing HIV incidence. The model includes stages of HIV infection, flexible sexual mixing, and changes in risk behavior over the epidemic. The model was calibrated to HIV prevalence data from South Africa using a Bayesian framework. Immediately after ART was introduced, more early transmission was associated with a smaller reduction in HIV incidence rate--consistent with the concern that a large amount of early transmission reduces the impact of treatment on incidence. However, the proportion of early transmission was not strongly related to the long-term reduction in incidence. This was because more early transmission resulted in a shorter generation time, in which case lower values for the basic reproductive number (R0) are consistent with observed epidemic growth, and R0 was negatively correlated with long-term intervention impact. The fraction of early transmission depends on biological factors, behavioral patterns, and epidemic stage and alone does not predict long-term intervention impacts. However, early transmission may be an important determinant in the outcome of short-term trials and evaluation of programs.

Beneficial effect of isoniazid preventive therapy and antiretroviral therapy on the incidence of tuberculosis in people living with HIV in Ethiopia

BACKGROUND

IPT with or without concomitant administration of ART is a proven intervention to prevent tuberculosis among PLHIV. However, there are few data on the routine implementation of this intervention and its effectiveness in settings with limited resources.

OBJECTIVES

To measure the level of uptake and effectiveness of IPT in reducing tuberculosis incidence in a cohort of PLHIV enrolled into HIV care between 2007 and 2010 in five hospitals in southern Ethiopia.

METHODS

A retrospective cohort analysis of electronic patient database was done. The independent effects of no intervention, "IPT-only," "IPT-before-ART," "IPT-and-ART started simultaneously," "ART-only," and "IPT-after-ART" on TB incidence were measured. Cox-proportional hazards regression was used to assess association of treatment categories with TB incidence.

RESULTS

Of 7,097 patients, 867 were excluded because they were transferred-in; a further 823 (12%) were excluded from the study because they were either identified to have TB through screening (292 patients) or were on TB treatment (531). Among the remaining 5,407 patients observed, IPT had been initiated for 39% of eligible patients. Children, male sex, advanced disease, and those in Pre-ART were less likely to be initiated on IPT. The overall TB incidence was 2.6 per 100 person-years. As compared to those with no intervention, use of "IPT-only" (aHR = 0.36, 95% CI = 0.19-0.66) and "ART-only" (aHR = 0.32, 95% CI = 0.24-0.43) were associated with significant reduction in TB incidence rate. Combining ART and IPT had a more profound effect. Starting IPT-before-ART (aHR = 0.18, 95% CI = 0.08-0.42) or simultaneously with ART (aHR = 0.20, 95% CI = 0.10-0.42) provided further reduction of TB at ∼ 80%.

CONCLUSIONS

IPT was found to be effective in reducing TB incidence, independently and with concomitant ART, under programme conditions in resource-limited settings. The level of IPT provision and effectiveness in reducing TB was encouraging in the study setting. Scaling up and strengthening IPT service in addition to ART can have beneficial effect in reducing TB burden among PLHIV in settings with high TB/HIV burden.

Mortality and causes of death among HIV-infected individuals in the country of Georgia: 1989-2012

Since 2004, the country of Georgia has provided antiretroviral therapy (ART) to all patients in need. A nationwide retrospective cohort study was conducted to assess the effect of universal access to ART on patterns of mortality and causes of death among HIV-infected individuals in Georgia. All known HIV-infected adult individuals (age ≥18 years) diagnosed from 1989 through 2012 were included. Rates and causes of death were determined using routinely collected data from the national HIV/AIDS database. Causes of death were classified according to the Coding of Death in HIV (CoDe) protocol. Between 1989 and 2012, 3,554 HIV-infected adults were registered in Georgia contributing to 13,572 person-years (PY) of follow-up. A total of 779 deaths were registered during follow-up. The mortality rate peaked in 2004 with 10.74 deaths per 100 PY (95% CI: 7.92-14.24) and significantly decreased after the universal availability of ART to 4.02 per 100 PY (95% CI: 3.28-4.87) in 2012. In multivariate analysis the strongest predictor of mortality was having AIDS at the time of HIV diagnosis (hazard ratio: 5.69, 95% CI: 4.72-6.85). AIDS-related diseases accounted for the majority of deaths (n=426, 54.7%). Tuberculosis (TB) was the leading cause of death accounting for 21% of the total deaths reported. Universal access to ART significantly reduced mortality among HIV-infected patients in Georgia. However, overall mortality rates remain high primarily due to late diagnosis, and TB remains a significant cause of death. Improving rates of early HIV diagnosis and ART initiation may further decrease mortality as well as prevent new HIV and TB infections.

Changes in population HIV RNA levels in Mbarara, Uganda, during scale-up of HIV antiretroviral therapy access

OBJECTIVE

In a rural Ugandan community scaling up antiretroviral therapy (ART), we sought to determine if population-based HIV RNA levels [population viral load (VL)] decreased from 2011 to 2012.

DESIGN

Serial cross-sectional analyses (May 2011 and May 2012) of a defined study community of 6300 persons in a district with HIV prevalence of 8%.

METHODS

We measured HIV-1 RNA (VL) levels on all individuals testing positive for HIV during a 5-day high-throughput multidisease community health campaign in May 2012 that recruited two-thirds of the population. We aggregated individual-level VL results into population VL metrics including the proportion of individuals with an undetectable VL and compared these VL metrics to those we previously reported for this geographic region in 2011.

RESULTS

In 2012, 223 of 2179 adults were HIV-seropositive adults (10%). Overall, among 208 of 223 HIV-seropositive adults in whom VL was tested, 53% had an undetectable VL [95% confidence interval (CI): 46 to 60], up from 37% (95% CI: 30 to 45; P = 0.02) in 2011. Seven (3%) individuals had a VL of >100,000 copies/mL in 2012, down from 21 (13%) in 2011 (P = 0.0007). Mean log (VL) (geometric mean) was 3.18 log (95% CI: 3.06 to 3.29 log) in 2012, down from 3.62 log (95% CI: 3.46 to 3.78 log) in 2011 (P < 0.0001). Similar reductions in population VL were seen among men and women.

CONCLUSIONS

Reductions in population VL metrics and a substantial increase in the proportion of persons with an undetectable VL were observed in a rural Ugandan community from 2011 to 2012. These findings from a resource-limited setting experiencing rapid ART scale-up may reflect a population-level effectiveness of expanding ART access.

Concentrated HIV subepidemics in generalized epidemic settings

PURPOSE OF REVIEW

A relatively neglected topic to date has been the occurrence of concentrated epidemics within generalized epidemic settings and the potential role of targeted interventions in such settings. We review recent studies in high-risk groups as well as findings relating to geographical heterogeneity and the potential for targeting 'high-transmission zones' in the 10 countries with highest HIV prevalence.

RECENT FINDINGS

Our review of recent studies confirmed earlier findings that, even in the context of generalized epidemics, MSM have a substantially higher prevalence than the general population. Estimates of prevalence of HIV among people who inject drugs (PWID) in sub-Saharan African countries are rarely available and, when they are, often outdated. We identified recent studies of sex workers in Kenya and Uganda. In all three cases - MSM, PWID, and sex workers - HIV prevalence estimates are mostly based on convenience. Moreover, good estimates of the total size of these populations are not available. Our review of recent studies of high-risk populations defined on the basis of geography showed high levels of both new and existing infections in Kenya (slums), South Africa (peri-urban communities), and Uganda (fishing villages).

SUMMARY

Recent empirical findings combined with evidence from phylogenetic studies and supported by mathematical models provide a clear rationale for testing the feasibility, acceptability, and effectiveness of targeted HIV prevention approaches in hyperendemic populations to supplement measures aimed at the general population.

Tuberculosis screening in high human immunodeficiency virus prevalence settings: turning promise into reality

Twenty years of sky-high tuberculosis (TB) incidence rates and high TB mortality in high human immunodeficiency virus (HIV) prevalence countries have so far not been matched by the same magnitude or breadth of responses as seen in malaria or HIV programmes. Instead, recommendations have been narrowly focused on people presenting to health facilities for investigation of TB symptoms, or for HIV testing and care. However, despite the recent major investment and scale-up of TB and HIV services, undiagnosed TB remains highly prevalent at community level, implying that diagnosis of TB remains slow and incomplete. This maintains high transmission rates and exposes people living with HIV to high rates of morbidity and mortality. More intensive use of TB screening, with broader definitions of target populations, expanded indications for screening both inside and outside of health facilities, and appropriate selection of new diagnostic tools, offers the prospect of rapidly improving population-level control of TB. Diagnostic accuracy of suitable (high throughput) algorithms remains the major barrier to realising this goal. In the present study, we review the evidence available to guide expanded TB screening in HIV-prevalent settings, ideally through combined TB-HIV interventions that provide screening for both TB and HIV, and maximise entry to HIV and TB care and prevention. Ideally, we would systematically test, treat and prevent TB and HIV comprehensively, offering both TB and HIV screening to all health facility attendees, TB households and all adults in the highest risk communities. However, we are still held back by inadequate diagnostics, financing and paucity of population-impact data. Relevant contemporary research showing the high need for potential gains, and pitfalls from expanded and intensified TB screening in high HIV prevalence settings are discussed in this review.

Data needs for evidence-based decisions: a tuberculosis modeler's 'wish list'

Infectious disease models are important tools for understanding epidemiology and supporting policy decisions for disease control. In the case of tuberculosis (TB), such models have informed our understanding and control strategies for over 40 years, but the primary assumptions of these models--and their most urgent data needs--remain obscure to many TB researchers and control officers. The structure and parameter values of TB models are informed by observational studies and experiments, but the evidence base in support of these models remains incomplete. Speaking from the perspective of infectious disease modelers addressing the broader TB research and control communities, we describe the basic structure common to most TB models and present a 'wish list' that would improve the evidence foundation upon which these models are built. As a comprehensive TB research agenda is formulated, we argue that the data needs of infectious disease models--our primary long-term decision-making tools--should figure prominently.

The impact of HIV treatment as prevention in the presence of other prevention strategies: lessons learned from a review of mathematical models set in resource-rich countries

OBJECTIVE

We aimed to assess the potential prevention benefits of HIV treatment as prevention (TasP) in resource-rich countries and examine the potential interactions between TasP and other prevention strategies by reviewing mathematical models of TasP.

METHOD

Multiple databases were searched for mathematical models published in the previous 5 years (from July 2007 to July 2012). The nine models located were set in Canada, Australia and the United States.

RESULTS

These models' predictions suggested that the impact of expanding treatment rates on expected new infections could range widely, from no decrease to a decrease of 76%, depending on the time horizon, assumptions and the form of TasP modeled. Increased testing, reducing sexually transmitted infections and reducing risky practices were also predicted to be important strategies for decreasing expected new infections. Sensitivity analysis suggests that current uncertainties such as the effectiveness of highly active antiretroviral therapy outside of heterosexual transmission, less than ideal adherence, and risk compensation, could impact on the success of TasP at the population level.

CONCLUSION

The results from large scale pilots and community randomized controlled trials will be useful in demonstrating how well this prevention approach works in real world settings, and in identifying the factors that are needed to support its effectiveness.

Challenges and potential barriers to the uptake of antiretroviral-based prevention in Asia and the Pacific region

Evidence has emerged over the past few years on the effectiveness of antiretroviral-based prevention technologies to prevent (i) HIV transmission while decreasing morbidity and mortality in HIV-infected persons, and (ii) HIV acquisition in HIV-uninfected individuals through pre-exposure prophylaxis (PrEP). Only few of the planned studies on treatment as prevention (TasP) are conducted in Asia. TasP might be more feasible and effective in concentrated rather than in generalised epidemics, as resources for HIV testing and antiretroviral treatment could focus on confined and much smaller populations than in the generalised epidemics observed in sub-Saharan Africa. Several countries such as Cambodia, China, Thailand and Vietnam, are now paving the way to success. Similar challenges arise for both TasP and PrEP. However, the operational issues for PrEP are amplified by the need for frequent retesting and ensuring adherence. This paper describes challenges for the implementation of antiretroviral-based prevention and makes the case that TasP and PrEP implementation research in Asia is much needed to provide insights into the feasibility of these interventions in populations where firm evidence of ‘real world’ effectiveness is still lacking.

Predicting the population impact of increased HIV testing and treatment in Australia

Introduction The treatment as prevention strategy has gained popularity as a way to reduce the incidence of HIV by suppressing viral load such that transmission risk is decreased. The effectiveness of the strategy also requires early diagnosis.

METHODS

Informed by data on the influence of diagnosis and treatment on reducing transmission risk, a model simulated the impact of increasing testing and treatment rates on the expected incidence of HIV in Australia under varying assumptions of treatment efficacy and risk compensation. The model utilises Australia's National HIV Registry data, and simulates disease progression, testing, treatment, transmission and mortality.

RESULTS

Decreasing the average time between infection and diagnosis by 30% is expected to reduce population incidence by 12% (~126 cases per year, 95% confidence interval (CI): 82-198). Treatment of all people living with HIV with CD4 counts <500cellsμL(-1) is expected to reduce new infections by 30.9% (95% CI: 15.9-37.6%) at 96% efficacy if no risk compensation occurs. The number of infections could increase up to 12.9% (95% CI: 20.1-7.4%) at 26% efficacy if a return to prediagnosis risk levels occur.

CONCLUSION

Treatment as prevention has the potential to prevent HIV infections but its effectiveness depends on the efficacy outside trial settings among men who have sex with men and the level of risk compensation. If antiretroviral therapy has high efficacy, risk compensation will not greatly change the number of infections. If the efficacy of antiretroviral therapy is low, risk compensation could lead to increased infections.

Outcomes among HIV-1 infected individuals first starting antiretroviral therapy with concurrent active TB or other AIDS-defining disease

Background

Tuberculosis (TB) is common among HIV-infected individuals in many resource-limited countries and has been associated with poor survival. We evaluated morbidity and mortality among individuals first starting antiretroviral therapy (ART) with concurrent active TB or other AIDS-defining disease using data from the “Prospective Evaluation of Antiretrovirals in Resource-Limited Settings” (PEARLS) study.

Methods

Participants were categorized retrospectively into three groups according to presence of active confirmed or presumptive disease at ART initiation: those with pulmonary and/or extrapulmonary TB (“TB” group), those with other non-TB AIDS-defining disease (“other disease”), or those without concurrent TB or other AIDS-defining disease (“no disease”). Primary outcome was time to the first of virologic failure, HIV disease progression or death. Since the groups differed in characteristics, proportional hazard models were used to compare the hazard of the primary outcome among study groups, adjusting for age, sex, country, screening CD4 count, baseline viral load and ART regimen.

Results

31 of 102 participants (30%) in the “TB” group, 11 of 56 (20%) in the “other disease” group, and 287 of 1413 (20%) in the “no disease” group experienced a primary outcome event (p = 0.042). This difference reflected higher mortality in the TB group: 15 (15%), 0 (0%) and 41 (3%) participants died, respectively (p<0.001). The adjusted hazard ratio comparing the “TB” and “no disease” groups was 1.39 (95% confidence interval: 0.93–2.10; p = 0.11) for the primary outcome and 3.41 (1.72–6.75; p<0.001) for death.

Conclusions

Active TB at ART initiation was associated with increased risk of mortality in HIV-1 infected patients.

HIV-1 disease progression during highly active antiretroviral therapy: an application using population-level data in British Columbia: 1996-2011

BACKGROUND

Accurately estimating rates of disease progression is of central importance in developing mathematical models used to project outcomes and guide resource allocation decisions. Our objective was to specify a multivariate regression model to estimate changes in disease progression among individuals on highly active antiretroviral treatment in British Columbia, Canada, 1996-2011.

METHODS

We used population-level data on disease progression and antiretroviral treatment utilization from the BC HIV Drug Treatment Program. Disease progression was captured using longitudinal CD4 and plasma viral load testing data, linked with data on antiretroviral treatment. The study outcome was categorized into (CD4 count ≥ 500, 500-350, 350-200, <200 cells/mm, and mortality). A 5-state continuous-time Markov model was used to estimate covariate-specific probabilities of CD4 progression, focusing on temporal changes during the study period.

RESULTS

A total of 210,083 CD4 measurements among 7421 individuals with HIV/AIDS were included in the study. Results of the multivariate model suggested that current highly active antiretroviral treatment at baseline, lower baseline CD4 (<200 cells/mm), and extended durations of elevated plasma viral load were each associated with accelerated progression. Immunological improvement was accelerated significantly from 2004 onward, with 23% and 46% increases in the probability of CD4 improvement from the fourth CD4 stratum (CD4 < 200) in 2004-2008 and 2008-2011, respectively.

CONCLUSION

Our results demonstrate the impact of innovations in antiretroviral treatment and treatment delivery at the population level. These results can be used to estimate a transition probability matrix flexible to changes in the observed mix of clients in different clinical stages and treatment regimens over time.

Antiretroviral treatment of HIV-1 prevents transmission of HIV-1: where do we go from here?

Antiretroviral drugs that inhibit viral replication were expected to reduce transmission of HIV by lowering the concentration of HIV in the genital tract. In 11 of 13 observational studies, antiretroviral therapy (ART) provided to an HIV-infected index case led to greatly reduced transmission of HIV to a sexual partner. In the HPTN 052 randomised controlled trial, ART used in combination with condoms and counselling reduced HIV transmission by 96·4%. Evidence is growing that wider, earlier initiation of ART could reduce population-level incidence of HIV. However, the full benefits of this strategy will probably need universal access to very early ART and excellent adherence to treatment. Challenges to this approach are substantial. First, not all HIV-infected individuals can be located, especially people with acute and early infection who are most contagious. Second, the ability of ART to prevent HIV transmission in men who have sex with men (MSM) and people who use intravenous drugs has not been shown. Indeed, the stable or increased incidence of HIV in MSM in some communities where widespread use of ART has been established emphasises the concern that not enough is known about treatment as prevention for this crucial population. Third, although US guidelines call for immediate use of ART, such guidelines have not been embraced worldwide. Some experts do not believe that immediate or early ART is justified by present evidence, or that health-care infrastructure for this approach is sufficient. These concerns are very difficult to resolve. Ongoing community-based prospective trials of early ART are likely to help to establish the population-level benefit of ART, and-if successful-to galvanise treatment as prevention.

Modelling the strategic use of antiretroviral therapy for the treatment and prevention of HIV

Nathan Ford and Gottfried Hirnschall reflect on recent research by Jan Hontelez and colleagues published in this week's PLOS Medicine. The authors argue that the future HIV modeling efforts should focus on helping programs make choices about which interventions need to be prioritized in order to achieve the levels of enrollment and retention in care required to maximize the prevention benefit of ART. Please see later in the article for the Editors' Summary.

The cascade of HIV care in British Columbia, Canada, 1996-2011: a population-based retrospective cohort study

BACKGROUND

The cascade of HIV care has become a focal point for implementation efforts to maximise the individual and public health benefits of antiretroviral therapy. We aimed to characterise longitudinal changes in engagement with the cascade of HIV care in British Columbia, Canada, from 1996 to 2011.

METHODS

We used estimates of provincial HIV prevalence from the Public Health Agency of Canada and linked provincial population-level data to define, longitudinally, the numbers of individuals in each of the eight stages of the cascade of HIV care (HIV infected, diagnosed, linked to HIV care, retained in HIV care, highly active antiretroviral therapy (HAART) indicated, on HAART, adherent to HAART, and virologically suppressed) in British Columbia from 1996 to 2011. We used sensitivity analyses to determine the sensitivity of cascade-stage counts to variations in their definitions.

FINDINGS

13,140 people were classified as diagnosed with HIV/AIDS in British Columbia during the study period. We noted substantial improvements over time in the proportions of individuals at each stage of the cascade of care. Based on prevalence estimates, the proportion of unidentified HIV-positive individuals decreased from 49·0% (estimated range 36·2-57·5%) in 1996 to 29·0% (11·6-40·7%) in 2011, and the proportion of HIV-positive people with viral suppression reached 34·6% (29·0-43·1%) in 2011.

INTERPRETATION

Careful mapping of the cascade of care is crucial to understanding what further efforts are needed to maximise the beneficial effects of available interventions and so inform efforts to contain the spread of HIV/AIDS.

FUNDING

British Columbia Ministry of Health, US National Institute on Drug Abuse (National Institutes of Health).

Steps towards preventive HIV treatment in Fujian, China: problems identified via an assessment of initial antiretroviral therapy provision

BACKGROUND

At the end of 2009, a total of 501 AIDS patients were receiving antiretroviral therapy (ART) in Fujian Province in China, yet there were no assessments to determine treatment efficacy and HIV-1 preventive potency under the current health care delivery system.

METHODS

During the period of 2005-2009, we assessed the outcomes of initial ART by following up 381 patients for 12 months in Fujian Province. CD4⁺ T-lymphocyte (CD4) count, plasma viral load (VL), and patient characteristics were analysed. The results were compared between 4 groups divided by the baseline CD4 values at the 25, 50 (median), and 75 percentiles.

FINDINGS

Over three-quarters of the subjects reported heterosexual contact as the probable route of transmission. After 12 months of ART, CD4 recovery varied between the 4 groups (P < 0.001), but VL sharply declined regardless of the baseline CD4 count (P = 0.136). Although this VL decline indicates the potency of ART as an HIV-1 prevention tool, the time between positive diagnosis and ART initiation suggests serious delay in both diagnosis and treatment; the medians of periods for the lowest and highest baseline CD4 quartiles were 1.2 and 9.6 months, respectively.

CONCLUSION

Current limitations in VL determination make it difficult to assess the efficacy of initial ART, and delays in diagnosis and treatment suggest that subjects contributed to HIV-1 transmission while they were not receiving ART. The current National Free ART scheme does not provide free treatment for sexually transmitted infection (STI), and there is no link between ART and the STI care delivery system. This may interfere with the HIV-1 preventive potency of ART. We highly recommend establishing a collaborating mechanism with STI care, strengthening the VL determination system, and promoting HIV tests and early ART initiation.

Can combination prevention strategies reduce HIV transmission in generalized epidemic settings in Africa? The HPTN 071 (PopART) study plan in South Africa and Zambia

The HIV Prevention Trials Network (HPTN) is conducting the HPTN 071 (PopART) study in 21 communities in Zambia and South Africa with support from a consortium of funders. HPTN 071 (PopART) is a community-randomized trial of a combination prevention strategy to reduce HIV incidence in the context of the generalized epidemic of southern Africa. The full PopART intervention strategy is anchored in home-based HIV testing and facilitated linkage of HIV-infected persons to care through community health workers and universal antiretroviral therapy for seropositive persons regardless of CD4+ cell count or HIV viral load. To further reduce the risk of HIV acquisition among uninfected individuals, the study aims to expand voluntary medical male circumcision, diagnosis and treatment of sexually transmitted infections, behavioral counseling, and condom distribution. The full PopART intervention strategy also incorporates promotion of other interventions designed to reduce HIV and tuberculosis transmission, including optimization of the prevention of mother-to-child HIV transmission and enhanced individual and public health tuberculosis services. Success for the PopART strategy depends on the ability to increase coverage for the study interventions whose uptake is a necessary antecedent to a prevention effect. Processes will be measured to assess the degree of penetration of the interventions into the communities. A randomly sampled population cohort from each community will be used to measure the impact of the PopART strategy on HIV incidence over 3 years. We describe the strategy being tested and progress to date in the HPTN 071 (PopART) study.

The potential impact of expanding antiretroviral therapy and combination prevention in Vietnam: towards elimination of HIV transmission

BACKGROUND

Few studies have assessed the effects of antiretroviral therapy (ART) to prevent HIV transmission in Asian HIV epidemics. Vietnam has a concentrated HIV epidemic with the highest prevalence among people who inject drugs. We investigated the impact of expanded HIV testing and counseling (HTC) and early ART, combined with other prevention interventions on HIV transmission.

METHODS

A deterministic mathematical model was developed using HIV prevalence trends in Can Tho province, Vietnam. Scenarios included offering periodic HTC and immediate ART with and without targeting subpopulations and examining combined strategies with methadone maintenance therapy and condom use.

RESULTS

From 2011 to 2050, maintaining current interventions will incur an estimated 18,115 new HIV infections and will cost US $22.1 million (reference scenario). Annual HTC and immediate treatment, if offered to all adults, will reduce new HIV infections by 14,513 (80%) and will cost US $76.9 million. Annual HTC and immediate treatment offered only to people who inject drugs will reduce new infections by 13,578 (75%) and will cost only US $23.6 million. Annual HTC and immediate treatment for key populations, combined with scale-up of methadone maintenance therapy and condom use, will reduce new infections by 14,723 (81%) with similar costs (US $22.7 million). This combination prevention scenario will reduce the incidence to less than 1 per 100,000 in 14 years and will result in a relative cost saving after 19 years.

CONCLUSIONS

Targeted periodic HTC and immediate ART combined with other interventions is cost-effective and could lead to potential elimination of HIV in Can Tho.

Towards universal voluntary HIV testing and counselling: a systematic review and meta-analysis of community-based approaches

BACKGROUND

Effective national and global HIV responses require a significant expansion of HIV testing and counselling (HTC) to expand access to prevention and care. Facility-based HTC, while essential, is unlikely to meet national and global targets on its own. This article systematically reviews the evidence for community-based HTC.

METHODS AND FINDINGS

PubMed was searched on 4 March 2013, clinical trial registries were searched on 3 September 2012, and Embase and the World Health Organization Global Index Medicus were searched on 10 April 2012 for studies including community-based HTC (i.e., HTC outside of health facilities). Randomised controlled trials, and observational studies were eligible if they included a community-based testing approach and reported one or more of the following outcomes: uptake, proportion receiving their first HIV test, CD4 value at diagnosis, linkage to care, HIV positivity rate, HTC coverage, HIV incidence, or cost per person tested (outcomes are defined fully in the text). The following community-based HTC approaches were reviewed: (1) door-to-door testing (systematically offering HTC to homes in a catchment area), (2) mobile testing for the general population (offering HTC via a mobile HTC service), (3) index testing (offering HTC to household members of people with HIV and persons who may have been exposed to HIV), (4) mobile testing for men who have sex with men, (5) mobile testing for people who inject drugs, (6) mobile testing for female sex workers, (7) mobile testing for adolescents, (8) self-testing, (9) workplace HTC, (10) church-based HTC, and (11) school-based HTC. The Newcastle-Ottawa Quality Assessment Scale and the Cochrane Collaboration's "risk of bias" tool were used to assess the risk of bias in studies with a comparator arm included in pooled estimates. 117 studies, including 864,651 participants completing HTC, met the inclusion criteria. The percentage of people offered community-based HTC who accepted HTC was as follows: index testing, 88% of 12,052 participants; self-testing, 87% of 1,839 participants; mobile testing, 87% of 79,475 participants; door-to-door testing, 80% of 555,267 participants; workplace testing, 67% of 62,406 participants; and school-based testing, 62% of 2,593 participants. Mobile HTC uptake among key populations (men who have sex with men, people who inject drugs, female sex workers, and adolescents) ranged from 9% to 100% (among 41,110 participants across studies), with heterogeneity related to how testing was offered. Community-based approaches increased HTC uptake (relative risk [RR] 10.65, 95% confidence interval [CI] 6.27-18.08), the proportion of first-time testers (RR 1.23, 95% CI 1.06-1.42), and the proportion of participants with CD4 counts above 350 cells/µl (RR 1.42, 95% CI 1.16-1.74), and obtained a lower positivity rate (RR 0.59, 95% CI 0.37-0.96), relative to facility-based approaches. 80% (95% CI 75%-85%) of 5,832 community-based HTC participants obtained a CD4 measurement following HIV diagnosis, and 73% (95% CI 61%-85%) of 527 community-based HTC participants initiated antiretroviral therapy following a CD4 measurement indicating eligibility. The data on linking participants without HIV to prevention services were limited. In low- and middle-income countries, the cost per person tested ranged from US$2-US$126. At the population level, community-based HTC increased HTC coverage (RR 7.07, 95% CI 3.52-14.22) and reduced HIV incidence (RR 0.86, 95% CI 0.73-1.02), although the incidence reduction lacked statistical significance. No studies reported any harm arising as a result of having been tested.

CONCLUSIONS

Community-based HTC achieved high rates of HTC uptake, reached people with high CD4 counts, and linked people to care. It also obtained a lower HIV positivity rate relative to facility-based approaches. Further research is needed to further improve acceptability of community-based HTC for key populations. HIV programmes should offer community-based HTC linked to prevention and care, in addition to facility-based HTC, to support increased access to HIV prevention, care, and treatment.

REVIEW REGISTRATION

International Prospective Register of Systematic Reviews CRD42012002554 Please see later in the article for the Editors' Summary.

Outcomes and impact of HIV prevention, ART and TB programs in Swaziland--early evidence from public health triangulation

INTRODUCTION

Swaziland's severe HIV epidemic inspired an early national response since the late 1980s, and regular reporting of program outcomes since the onset of a national antiretroviral treatment (ART) program in 2004. We assessed effectiveness outcomes and mortality trends in relation to ART, HIV testing and counseling (HTC), tuberculosis (TB) and prevention of mother to child transmission (PMTCT).

METHODS

Data triangulated include intervention coverage and outcomes according to program registries (2001-2010), hospital admissions and deaths disaggregated by age and sex (2001-2010) and population mortality estimates from the 1997 and 2007 censuses and the 2007 demographic and health survey.

RESULTS

By 2010, ART reached 70% of the estimated number of people living with HIV/AIDS with CD4<350/mm(3), with progressively improving patient retention and survival. As of 2010, 88% of health facilities providing antenatal care offered comprehensive PMTCT services. The HTC program recorded a halving in the proportion of adults tested who were HIV-infected; similarly HIV infection rates among HIV-exposed babies halved from 2007 to 2010. Case fatality rates among hospital patients diagnosed with HIV/AIDS started to decrease from 2005-6 in adults and especially in children, contrasting with stable case fatality for other causes including TB. All-cause child in-patient case fatality rates started to decrease from 2005-6. TB case notifications as well as rates of HIV/TB co-infection among notified TB patients continued a steady increase through 2010, while coverage of HIV testing and CPT for co-infected patients increased to above 80%.

CONCLUSION

Against a background of high, but stable HIV prevalence and decreasing HIV incidence, we documented early evidence of a mortality decline associated with the expanded national HIV response since 2004. Attribution of impact to specific interventions (versus natural epidemic dynamics) will require additional data from future household surveys, and improved routine (program, surveillance, and hospital) data at district level.

When to start antiretroviral therapy: the need for an evidence base during early HIV infection

BACKGROUND

Strategies for use of antiretroviral therapy (ART) have traditionally focused on providing treatment to persons who stand to benefit immediately from initiating the therapy. There is global consensus that any HIV+ person with CD4 counts less than 350 cells/μl should initiate ART. However, it remains controversial whether ART is indicated in asymptomatic HIV-infected persons with CD4 counts above 350 cells/μl, or whether it is more advisable to defer initiation until the CD4 count has dropped to 350 cells/μl. The question of when the best time is to initiate ART during early HIV infection has always been vigorously debated. The lack of an evidence base from randomized trials, in conjunction with varying degrees of therapeutic aggressiveness and optimism tempered by the risks of drug resistance and side effects, has resulted in divided expert opinion and inconsistencies among treatment guidelines.

DISCUSSION

On the basis of recent data showing that early ART initiation reduces heterosexual HIV transmission, some countries are considering adopting a strategy of universal treatment of all HIV+ persons irrespective of their CD4 count and whether ART is of benefit to the individual or not, in order to reduce onward HIV transmission. Since ART has been found to be associated with both short-term and long-term toxicity, defining the benefit:risk ratio is the critical missing link in the discussion on earlier use of ART. For early ART initiation to be justified, this ratio must favor benefit over risk. An unfavorable ratio would argue against using early ART.

SUMMARY

There is currently no evidence from randomized controlled trials to suggest that a strategy of initiating ART when the CD4 count is above 350 cells/μl (versus deferring initiation to around 350 cells/μl) results in benefit to the HIV+ person and data from observational studies are inconsistent. Large, clinical endpoint-driven randomized studies to determine the individual health benefits versus risks of earlier ART initiation are sorely needed.

The marginal willingness-to-pay for attributes of a hypothetical HIV vaccine

This paper estimates the marginal willingness-to-pay for attributes of a hypothetical HIV vaccine using discrete choice modeling. We use primary data from 326 respondents from Bangkok and Chiang Mai, Thailand, in 2008-2009, selected using purposive, venue-based sampling across two strata. Participants completed a structured questionnaire and full rank discrete choice modeling task administered using computer-assisted personal interviewing. The choice experiment was used to rank eight hypothetical HIV vaccine scenarios, with each scenario comprising seven attributes (including cost) each of which had two levels. The data were analyzed in two alternative specifications: (1) best-worst; and (2) full-rank, using logit likelihood functions estimated with custom routines in Gauss matrix programming language. In the full-rank specification, all vaccine attributes are significant predictors of probability of vaccine choice. The biomedical attributes of the hypothetical HIV vaccine (efficacy, absence of VISP, absence of side effects, and duration of effect) are the most important attributes for HIV vaccine choice. On average respondents are more than twice as likely to accept a vaccine with 99% efficacy, than a vaccine with 50% efficacy. This translates to a willingness to pay US$383 more for a high efficacy vaccine compared with the low efficacy vaccine. Knowledge of the relative importance of determinants of HIV vaccine acceptability is important to ensure the success of future vaccination programs. Future acceptability studies of hypothetical HIV vaccines should use more finely grained biomedical attributes, and could also improve the external validity of results by including more levels of the cost attribute.

Examining the evidence on the causal effect of HAART on transmission of HIV using the Bradford Hill criteria

In recent years, evidence has accumulated regarding the ability of HAART to prevent HIV transmission. Early supportive evidence was derived from observational, ecological and population-based studies. More recently, a randomized clinical trial showed that immediate use of HAART led to a 96% decrease in HIV transmission events within HIV serodiscordant heterosexual couples. However, the generalizability of the effect of HAART, and the population-level impact on HIV transmission continues to generate substantial debate. We, therefore, conducted a review of the evidence regarding the preventive effect of HAART on HIV transmission within the context of the Bradford Hill criteria for causality. Taken together, we find the accumulated evidence supporting HIV treatment as prevention meets each of the Bradford Hill criteria for causality. We conclude that the opportunity cost of inaction while waiting for additional evidence on the generalizability of effect in other risk groups is too high. Efforts should be redoubled to mobilize the financial capital and political will to optimize implementation of HIV Treatment as Prevention strategies on a wide scale.