Causal Structural Learning on MPHIA Individual Dataset

The Population-based HIV Impact Assessment (PHIA) is an ongoing project that conducts nationally representative HIV-focused surveys for measuring national and regional progress toward UNAIDS' 90-90-90 targets, the primary strategy to end the HIV epidemic. We believe the PHIA survey offers a unique opportunity to better understand the key factors that drive the HIV epidemics in the most affected countries in sub-Saharan Africa. In this article, we propose a novel causal structural learning algorithm to discover important covariates and potential causal pathways for 90-90-90 targets. Existing constrained-based causal structural learning algorithms are quite aggressive in edge removal. The proposed algorithm preserves more information about important features and potential causal pathways. It is applied to the Malawi PHIA (MPHIA) data set and leads to interesting results. For example, it discovers age and condom usage to be important for female HIV awareness; the number of sexual partners to be important for male HIV awareness; and knowing the travel time to HIV care facilities leads to a higher chance of being treated for both females and males. We further compare and validate the proposed algorithm using BIC and using Monte Carlo simulations, and show that the proposed algorithm achieves improvement in true positive rates in important feature discovery over existing algorithms.

HIV Care Cascade Among Adolescents in a "Test and Treat" Community-Based Intervention: HPTN 071 (PopART) for Youth Study

PURPOSE

The PopART for Youth (P-ART-Y) study was nested within the HPTN 071 (PopART) trial, a three-arm community randomized trial in 21 communities in Zambia and South Africa. The P-ART-Y study evaluated the acceptability and uptake of a combination HIV prevention package among young people. We report on the HIV care cascade for adolescents aged 10-19 years from 14 communities receiving the full HIV prevention package in Zambia and South Africa.

METHODS

Adolescents were offered participation in the PopART intervention, which included universal home-based HIV testing, linkage to care, antiretroviral therapy (ART) adherence, and other services. Data were collected from September 2016 to December 2017, covering the third round (R3) of the intervention.

RESULTS

We enumerated (listed) 128,241 adolescents (Zambia: 95,295 and South Africa: 32,946). Of the adolescents offered HIV testing, 81.9% accepted in Zambia and 70.3% in South Africa. Knowledge of HIV status was higher among older adolescents and increased from 31.4% before R3 to 88.3% at the end of R3 in Zambia and from 28.3% to 79.5% in South Africa. Overall, there were 1,710 (1.9%) adolescents identified as living with HIV by the end of R3 (515 new diagnoses and 1,195 self-reported). Of the new diagnoses, 335 (65.0%) were girls aged 15-19 years. The median time to initiate ART was 5 months. ART coverage before and after R3 increased from 61.3% to 78.7% in Zambia and from 65.6% to 87.8% in South Africa, with boys having higher uptake than girls in both countries.

CONCLUSIONS

The PopART intervention substantially increased coverage toward the first and second UNAIDS 90-90-90 targets in adolescents.

Prevalence of nonsuppressed viral load and associated factors among HIV-positive adults receiving antiretroviral therapy in Eswatini, Lesotho, Malawi, Zambia and Zimbabwe (2015 to 2017): results from population-based nationally representative surveys

INTRODUCTION

The global target for 2020 is that ≥90% of people living with HIV (PLHIV) receiving antiretroviral therapy (ART) will achieve viral load suppression (VLS). We examined VLS and its determinants among adults receiving ART for at least four months.

METHODS

We analysed data from the population-based HIV impact assessment (PHIA) surveys in Eswatini, Lesotho, Malawi, Zambia and Zimbabwe (2015 to 2017). PHIA surveys are nationally representative, cross-sectional household surveys. Data collection included structured interviews, home-based HIV testing and laboratory testing. Blood samples from PLHIV were analysed for HIV RNA, CD4 counts and recent exposure to antiretroviral drugs (ARVs). We calculated representative estimates for the prevalence of VLS (viral load <1000 copies/mL), nonsuppressed viral load (NVL; viral load ≥1000 copies/mL), virologic failure (VF; ARVs present and viral load ≥1000 copies/mL), interrupted ART (ARVs absent and viral load ≥1000 copies/mL) and rates of switching to second-line ART (protease inhibitors present) among PLHIV aged 15 to 59 years who participated in the PHIA surveys in Eswatini, Lesotho, Malawi, Zambia and Zimbabwe, initiated ART at least four months before the survey and were receiving ART at the time of the survey (according to self-report or ARV testing). We calculated odds ratios and incidence rate ratios for factors associated with NVL, VF, interrupted ART, and switching to second-line ART.

RESULTS

We included 9200 adults receiving ART of whom 88.8% had VLS and 11.2% had NVL including 8.2% who experienced VF and 3.0% who interrupted ART. Younger age, male sex, less education, suboptimal adherence, receiving nevirapine, HIV non-disclosure, never having married and residing in Zimbabwe, Lesotho or Zambia were associated with higher odds of NVL. Among people with NVL, marriage, female sex, shorter ART duration, higher CD4 count and alcohol use were associated with lower odds for VF and higher odds for interrupted ART. Many people with VF (44.8%) had CD4 counts <200 cells/µL, but few (0.31% per year) switched to second-line ART.

CONCLUSIONS

Countries are approaching global VLS targets for adults. Treatment support, in particular for younger adults, and people with higher CD4 counts, and switching of people to protease inhibitor- or integrase inhibitor-based regimens may further reduce NVL prevalence.

Integrating and Interpreting Findings from the Latest Treatment as Prevention Trials

PURPOSE OF REVIEW

In 2018-2019, studies were published assessing the effectiveness of reducing HIV incidence by expanding HIV testing, linkage to HIV treatment, and assistance to persons living with HIV to adhere to their medications (the "90-90-90" strategy). These tests of "treatment as prevention" (TasP) had complex results.

RECENT FINDINGS

The TasP/ANRS 12249 study in South Africa, the SEARCH study in Kenya and Uganda, and one comparison (arms A to C) of the HPTN 071 (PopART) study in South Africa and Zambia did not demonstrate a community impact on HIV incidence. In contrast, the Botswana Ya Tsie study and the second comparison (arms B to C) of PopART indicated significant ≈ 30% reductions in HIV incidence in the intervention communities where TasP was expanded. We discuss the results of these trials and outline future research and challenges. These include the efficient expansion of widespread HIV testing, better linkage to care, and viral suppression among all persons living with HIV. A top implementation science priority for the next decade is to determine what strategies to use in specific local contexts.

District-level strategies to control the HIV epidemic in Zimbabwe: a practical example of precision public health

Objective

We conducted a descriptive cross-sectional study using survey and programme data to assess district-level performance along the HIV care cascade (HIV testing target achievement, linkage to ART and ART coverage) in order to formulate district-specific recommendations, taking into consideration prevalence and yield of testing.

Results

Data from 60 districts were analysed. Forty-eight districts (80.0%) surpassed 90% of their 2018 HIV testing targets. Linkage to ART was less than 90% in 40 districts (83.3%). Thirty districts (50.0%) had ART coverage above 90%. Of the 30 districts with suboptimal (< 90%) ART coverage, 18 districts had achieved high HIV testing target but with suboptimal linkage to ART, 6 had achieved high HIV testing targets and high linkage to ART, 4 had both suboptimal HIV testing target achievement and linkage to ART and 2 had suboptimal HIV testing target achievement and high linkage to ART. Priority should be given to districts with suboptimal ART coverage. Remediation strategies should be tailored to address the poorly performing stage of the cascade in each of the districts.

How to Evolve the Response to the Global HIV Epidemic With New Metrics and Targets Based on Pre-Treatment CD4 Counts

PURPOSE OF THE REVIEW

Early diagnosis and treatment of HIV following seroconversion improves individual and population health. Using published data on pre-treatment CD4 cell counts, we benchmarked the level of immunodeficiency at HIV diagnosis and ART initiation in the "real world" against those of the treatment and control arms of landmark controlled trials that successfully reduced HIV-related deaths (INSIGHT/START) and onward HIV transmission (HPTN 052).

RECENT FINDINGS

The median CD4 count in the treatment vs. control arms of the INSIGHT/START trial and HPTN 052 were 650 vs. 408 cells/μL and 442 vs. 221 cells/μL, respectively. In the real world, recent global estimates of the median CD4 count at start of ART range from 234 to 350 cells/μL, and only 25% of those initiating ART do so early (i.e., with CD4 > 500 cells/μL). Recent global data on trends in the median CD4 count at diagnosis and ART initiation are not encouraging. We identify a critical need for new targets and metrics for persons newly diagnosed with HIV, newly enrolling in HIV care, and newly initiating ART, based on pre-treatment CD4 counts, to help increase the focus of implementation efforts on achieving earlier diagnosis, linkage to care, and ART initiation.

Improvements in the South African HIV care cascade: findings on 90-90-90 targets from successive population-representative surveys in North West Province

INTRODUCTION

To achieve epidemic control of HIV by 2030, countries aim to meet 90-90-90 targets to increase knowledge of HIV-positive status, initiation of antiretroviral therapy (ART) and viral suppression by 2020. We assessed the progress towards these targets from 2014 to 2016 in South Africa as expanded treatment policies were introduced using population-representative surveys.

METHODS

Data were collected in January to March 2014 and August to November 2016 in Dr. Ruth Segomotsi Mompati District, North West Province. Each multi-stage cluster sample included 46 enumeration areas (EA), a target of 36 dwelling units (DU) per EA, and a single resident aged 18 to 49 per DU. Data collection included behavioural surveys, rapid HIV antibody testing and dried blood spot collection. We used weighted general linear regression to evaluate differences in the HIV care continuum over time.

RESULTS

Overall, 1044 and 971 participants enrolled in 2014 and 2016 respectively with approximately 77% undergoing HIV testing. Despite increases in reported testing, known status among people living with HIV (PLHIV) remained similar at 68.7% (95% Confidence Interval (CI) = 60.9-75.6) in 2014 and 72.8% (95% CI = 63.6-80.4) in 2016. Men were consistently less likely than women to know their status. Among those with known status, PLHIV on ART increased significantly from 80.9% (95% CI = 71.9-87.4) to 91.5% (95% CI = 84.4-95.5). Viral suppression (<5000 copies/mL using DBS) among those on ART increased significantly from 55.0% (95% CI = 39.6-70.4) in 2014 to 81.4% (95% CI = 72.0-90.8) in 2016. Among all PLHIV an estimated 72.0% (95% CI = 63.8-80.1) of women and 45.8% (95% CI = 27.0-64.7) of men achieved viral suppression by 2016.

CONCLUSIONS

Over a period during which fixed-dose combination was introduced, ART eligibility expanded, and efforts to streamline treatment were implemented, major improvements in the second and third 90-90-90 targets were achieved. Achieving the first 90 target will require targeted and improved testing models for men.

Research priorities to inform "Treat All" policy implementation for people living with HIV in sub-Saharan Africa: a consensus statement from the International epidemiology Databases to Evaluate AIDS (IeDEA)

INTRODUCTION

"Treat All" - the treatment of all people with HIV, irrespective of disease stage or CD4 cell count - represents a paradigm shift in HIV care that has the potential to end AIDS as a public health threat. With accelerating implementation of Treat All in sub-Saharan Africa (SSA), there is a need for a focused agenda and research to identify and inform strategies for promoting timely uptake of HIV treatment, retention in care, and sustained viral suppression and addressing bottlenecks impeding implementation.

METHODS

The Delphi approach was used to develop consensus around research priorities for Treat All implementation in SSA. Through an iterative process (June 2017 to March 2018), a set of research priorities was collectively formulated and refined by a technical working group and shared for review, deliberation and prioritization by more than 200 researchers, implementation experts, policy/decision-makers, and HIV community representatives in East, Central, Southern and West Africa.

RESULTS AND DISCUSSION

The process resulted in a list of nine research priorities for generating evidence to guide Treat All policies, implementation strategies and monitoring efforts. These priorities highlight the need for increased focus on adolescents, men, and those with mental health and substance use disorders - groups that remain underserved in SSA and for whom more effective testing, linkage and care strategies need to be identified. The priorities also reflect consensus on the need to: (1) generate accurate national and sub-national estimates of the size of key populations and describe those who remain underserved along the HIV-care continuum; (2) characterize the timeliness of HIV care and short- and long-term HIV care continuum outcomes, as well as factors influencing timely achievement of these outcomes; (3) estimate the incidence and prevalence of HIV-drug resistance and regimen switching; and (4) identify cost-effective and affordable service delivery models and strategies to optimize uptake and minimize gaps, disparities, and losses along the HIV-care continuum, particularly among underserved populations.

CONCLUSIONS

Reflecting consensus among a broad group of experts, researchers, policy- and decision-makers, PLWH, and other stakeholders, the resulting research priorities highlight important evidence gaps that are relevant for ministries of health, funders, normative bodies and research networks.

Monitoring progress towards the first UNAIDS target: understanding the impact of people living with HIV who re-test during HIV-testing campaigns in rural Mozambique

INTRODUCTION

Awareness of HIV-infection goes beyond diagnosis, and encompasses understanding, acceptance, disclosure and initiation of the HIV-care. We aimed to characterize the HIV-positive population that underwent repeat HIV-testing without disclosing their serostatus and the impact on estimates of the first UNAIDS 90 target.

METHODS

This analysis was nested in a prospective cohort established in southern Mozambique which conducted three HIV-testing modalities: voluntary counselling and testing (VCT), provider-initiated counselling and testing (PICT) and home-based testing (HBT). Participants were given the opportunity to self-report their status to lay counsellors and HIV-positive diagnoses were verified for previous enrolment in care. This study included 1955 individuals diagnosed with HIV through VCT/PICT and 11,746 participants of a HBT campaign. Those who did not report their serostatus prior to testing, and were found to have a previous HIV-diagnosis, were defined as non-disclosures. Venue-stratified descriptive analyses were performed and factors associated with non-disclosure were estimated through log-binomial regression.

RESULTS

In the first round of 2500 adults randomized for HBT, 1725 were eligible for testing and 18.7% self-reported their HIV-positivity. Of those tested with a positive result, 38.9% were found to be non-disclosures. Similar prevalence of non-disclosures was found in clinical-testing modalities, 29.4% (95% CI 26.7 to 32.3) for PICT strategy and 13.0% (95% CI 10.9 to 15.3) for VCT. Prior history of missed visits (adjusted prevalence ratio (APR) 4.2, 95% CI 2.6 to 6.8), younger age (APR 2.5, 95% CI 1.4 to 4.4) and no prior history of treatment ((APR) 1.4, 95% CI 1.0 to 2.1) were significantly associated with non-disclosure as compared to patients who self-reported. When considering non-disclosures as people living with HIV (PLWHIV) aware of their HIV-status, the proportion of PLWHIV aware increased from 78.3% (95% CI 74.2 to 81.6) to 86.8% (95% CI 83.4 to 89.6).

CONCLUSION

More than one-third of individuals testing HIV-positive did not disclose their previous positive HIV-diagnosis to counsellors. This proportion varied according to testing modality and age. In the absence of an efficient and non-anonymous tracking system for HIV-testers, repeat testing of non-disclosures leads to wasted resources and may distort programmatic indicators. Developing interventions that ensure appropriate psychosocial support are needed to encourage this population to disclose their status and optimize scarce resources.

A tale of two countries: progress towards UNAIDS 90-90-90 targets in Botswana and Australia

UNAIDS 90-90-90 targets and Fast-Track commitments are presented as precursors to ending the AIDS epidemic by 2030, through effecting a 90% reduction in new HIV infections and AIDS-related deaths from 2010 levels (HIV epidemic control). Botswana, a low to middle-income country with the third-highest HIV prevalence, and Australia, a low-prevalence high-income country with an epidemic concentrated among men who have sex with men (MSM), have made significant strides towards achieving the UNAIDS 90-90-90 targets. These two countries provide lessons for different epidemic settings. This paper discusses the lessons that can be drawn from Botswana and Australia with respect to their success in HIV testing, treatment, viral suppression and other HIV prevention strategies for HIV epidemic control. Botswana and Australia are on target to achieving the 90-90-90 targets for HIV epidemic control, made possible by comprehensive HIV testing and treatment programmes in the two countries. As of 2015, 70% of all people assumed to be living with HIV had viral suppression in Botswana and Australia. However, HIV incidence remains above one per cent in the general population in Botswana and in MSM in Australia. The two countries have demonstrated that rapid HIV testing that is accessible and targeted at key and vulnerable populations is required in order to continue identifying new HIV infections. All citizens living with HIV in both countries are eligible for antiretroviral therapy (ART) and viral load monitoring through government-funded programmes. Notwithstanding their success in reducing HIV transmission to date, programmes in both countries must continue to be supported at current levels to maintain epidemic suppression. Scaled HIV testing, linkage to care, universal ART, monitoring patients on treatment over and above strengthened HIV prevention strategies (e.g. male circumcision and pre-exposure prophylaxis) will all continue to require funding. The progress that Botswana and Australia have made towards meeting the 90-90-90 targets is commendable. However, in order to reduce HIV incidence significantly towards 2030, there is a need for sustained HIV testing, linkage to care and high treatment coverage. Botswana and Australia provide useful lessons for developing countries with generalized epidemics and high-income countries with concentrated epidemics.