Treatment as prevention: translating efficacy trial results to population effectiveness

Comparative Effectiveness of Community-Based vs Clinic-Based Healthy Choices Motivational Intervention to Improve Health Behaviors Among Youth Living With HIV: A Randomized Clinical Trial

IMPORTANCE

Youth living with HIV make up one-quarter of new infections and have high rates of risk behaviors but are significantly understudied. Effectiveness trials in real-world settings are needed to inform program delivery.

OBJECTIVE

To compare the effectiveness of the Healthy Choices intervention delivered in a home or community setting vs a medical clinic.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial was conducted from November 1, 2014, to January 31, 2018, with 52 weeks of follow-up. Participants, recruited from 5 adolescent HIV clinics in the United States, were youths and young adults living with HIV aged 16 to 24 years who were fluent in English, were currently prescribed HIV medication, had a detectable viral load, and had used alcohol in the past 12 weeks. Individuals with an active psychosis that resulted in an inability to complete questionnaires were excluded. Data were analyzed from May to December, 2019.

INTERVENTIONS

Participants were randomized to receive the Healthy Choices intervention in either a home or clinic setting. Four 30-minute individual sessions based on motivational interviewing to improve (1) medication adherence and (2) drinking behavior were delivered during 10 weeks by trained community health workers. In session 1, participants chose which behavior to discuss first. Using motivational interviewing strategies, the community health worker elicited motivational language, guided the development of an individualized change plan while supporting autonomy, delivered feedback, and addressed knowledge gaps. Session 2 focused on the second target behavior. In subsequent sessions, community health workers reviewed the individualized change plan, monitored progress, guided problem solving, and helped maintain changes made.

MAIN OUTCOMES AND MEASURES

Primary outcomes were viral load and alcohol use change trajectories during 52 weeks of follow-up. Alcohol use severity and frequency were measured using the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) (scores range from 0 to 33, with higher scores indicating greater severity of alcohol-related problems) and number of drinks consumed each day over a 30-day period, with timeline followback.

RESULTS

A total of 183 young people living with HIV (145 male [79.2%]; mean [SD] age, 21.4 [1.9] y) were randomized to the home setting (n = 90) or clinical setting (n = 93). Using growth-curve analysis, both groups showed declines in viral load after the intervention: among participants with available viral load information, in the home group, 12 participants (21%) had an undetectable viral load at 16 weeks, 12 (22%) at 28 weeks, and 10 (20%) at 52 weeks; in the clinic group, 16 participants (24%) had an undetectable viral load at 16 weeks, 20 (39%) at 28 weeks, and 18 (35%) at 52 weeks. However, the clinic group maintained gains, whereas those counseled at home had a significantly different and increasing trajectory during follow-up (unstandardized β = -0.07; 95% CI,-0.14 to -0.01; P = .02). A similar pattern was observed in ASSIST scores during follow-up, with reduced ASSIST scores in the clinic group (unstandardized β = -0.44; 95% CI,-0.81 to -0.07; P = .02).

CONCLUSIONS AND RELEVANCE

In this trial, the Healthy Choices intervention resulted in improvements in viral load and alcohol use over 12 months. Unexpectedly, the clinic setting outperformed home-based delivery for viral suppression. Although cross-sectional differences in ASSIST scores were nonsignificant, clinic delivery did improve the trajectory of ASSIST scores during follow-up. Thus, clinics may be the more effective site for interventions aimed at viral load reduction for young people living with HIV.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01969461.

HIV testing and engagement in care among highly vulnerable female sex workers: implications for treatment as prevention models

BACKGROUND

Although emerging Treatment as Prevention models can be effective in reducing HIV incidence among high-risk populations, many HIV infected individuals remain undiagnosed or fail to engage in HIV care.

METHODS

This study examined the factors associated with HIV testing and care among a population of substance using female sex workers.

RESULTS

Recent HIV testing was associated with higher education level, having a regular health care provider or clinic, recent crack use, and higher sexual risk behaviors; HIV treatment utilization was associated with higher levels of social support, having a regular health care provider or clinic, housing stability and insurance coverage. Qualitative data revealed HIV-related stigma, denial, social isolation, and substance use as barriers to HIV testing and treatment; social support and accessibility of services were key enablers.

CONCLUSIONS

Improving HIV testing and linkage to treatment among female sex workers will require structural initiatives to reduce stigma and increase service seeking support.

Palliative HIV care: opportunities for biomedical and behavioral change

Advances in treatment are contributing to substantial increases in life expectancy for individuals living with HIV, prompting a need to develop care models for the effective management of HIV as a chronic illness. With many individuals continuing to experience symptoms and complications that add to the disease burden across the spectrum of HIV disease, the discussion herein explores the complementary role that early palliative care can play in HIV primary care as a strategy for enhancing long-term quality of life. After first defining the concept of early palliative care, its scope in the context of current clinical realities in HIV treatment and implications for HIV care models is described. After reviewing the emerging extant research literature on HIV palliative care outcomes, a program description is offered as an illustration of how palliative care integration with HIV primary care can be achieved.

Role of oral pre-exposure prophylaxis (PrEP) in current and future HIV prevention strategies

Treatment as prevention is expected to have a major role in reducing HIV incidence, but other prevention interventions will also be required to bring the epidemic under control, particularly among key populations. One or more forms of pre-exposure prophylaxis (PrEP) will likely play a critical role. Oral PrEP with emtricitabine-tenofovir (Truvada®) is currently available in the US and some other countries, but uptake has been slow. We review the concerns that have contributed to this slow uptake and discuss current and future research in this critical area of HIV prevention research.

Modeling scenarios for the end of AIDS

At the end of 2012, 3 decades after the human immunodeficiency virus (HIV) was first identified, neither a cure nor a fully preventive vaccine was available. Despite multiple efforts, the epidemic remains an exceptional public health challenge. At the end of 2012, it was estimated that, globally, 35 million people were living with HIV, 2.3 million had become newly infected, and 1.6 million had died from AIDS-related causes. Despite substantial prevention efforts and increases in the number of individuals on highly active antiretroviral therapy (HAART), the epidemic burden continues to be high. Here, we provide a brief overview of the epidemiology of HIV transmission, the work that has been done to date regarding HIV modeling in different settings around the world, and how to finance the response to the HIV epidemic. In addition, we suggest discussion topics on how to move forward with the prevention agenda and highlight the role of treatment as prevention (TasP) in curbing the epidemic.

Phylogenetic studies of transmission dynamics in generalized HIV epidemics: an essential tool where the burden is greatest?

Efficient and effective HIV prevention measures for generalized epidemics in sub-Saharan Africa have not yet been validated at the population level. Design and impact evaluation of such measures requires fine-scale understanding of local HIV transmission dynamics. The novel tools of HIV phylogenetics and molecular epidemiology may elucidate these transmission dynamics. Such methods have been incorporated into studies of concentrated HIV epidemics to identify proximate and determinant traits associated with ongoing transmission. However, applying similar phylogenetic analyses to generalized epidemics, including the design and evaluation of prevention trials, presents additional challenges. Here we review the scope of these methods and present examples of their use in concentrated epidemics in the context of prevention. Next, we describe the current uses for phylogenetics in generalized epidemics and discuss their promise for elucidating transmission patterns and informing prevention trials. Finally, we review logistic and technical challenges inherent to large-scale molecular epidemiological studies of generalized epidemics and suggest potential solutions.

French HIV experts on early antiretroviral treatment for prevention: uncertainty and heterogeneity

Early use of highly active antiretroviral treatment (ART) in people living with HIV for HIV prevention has gained legitimacy but remains controversial. Nineteen French HIV experts with diverse specializations (over half of whom were clinicians) were qualitatively interviewed on their views about ART irrespective of CD4 count of more than 500 cells/mm3 for purposes of HIV prevention, which is not systematically recommended in France. Content analysis identified 2 broad categories: individual considerations (subcategories: patient health and well-being; patient preparedness and choice) and collective considerations (subcategories:HIV transmission risk; impact on the epidemic; cost). Uncertainty surrounded many experts' considerations, and unity was lacking on key issues (eg, candidacy for early preventive treatment, expected clinical- and population-level effects). An umbrella theme labeled "Weighing the merits of early ART in the face of uncertainties was identified. Our analyses raise doubts about the current acceptability of widespread implementation of early ART for HIV prevention in France.

Antiretroviral therapy for refugees and internally displaced persons: a call for equity

Joshua Mendelsohn and colleagues discuss the moral, legal, and public health principles and recent evidence that strongly suggest that refugees and internally displaced people should have equal access to HIV treatment and support as host nationals and give detailed recommendations for refugees and internally displaced people accessing antiretroviral therapy in stable settings. Please see later in the article for the Editors' Summary

Sexual risk behaviour and viral suppression among HIV-infected adults receiving medical care in the United States

OBJECTIVE

To describe the prevalence and association of sexual risk behaviours and viral suppression among HIV-infected adults in the United States.

DESIGN

Cross-sectional analysis of weighted data from a probability sample of HIV-infected adults receiving outpatient medical care. The facility and patient response rates were 76 and 51%, respectively.

METHODS

We analysed 2009 interview and medical record data. Sexual behaviours were self-reported in the past 12 months. Viral suppression was defined as all viral load measurements in the medical record during the past 12 months less than 200 copies/ml.

RESULTS

An estimated 98 022 (24%) HIV-infected adults engaged in unprotected vaginal or anal sex; 50 953 (12%) engaged in unprotected vaginal or anal sex with at least one partner of negative or unknown HIV status; 23 933 (6%) did so while not virally suppressed. Persons who were virally suppressed were less likely than persons who were not suppressed to engage in vaginal or anal sex [prevalence ratio, 0.88; 95% confidence interval (CI), 0.82-0.93]; unprotected vaginal or anal sex (prevalence ratio, 0.85; 95% CI, 0.73-0.98); and unprotected vaginal or anal sex with a partner of negative or unknown HIV status (prevalence ratio, 0.79; 95% CI, 0.64-0.99).

CONCLUSION

The majority of HIV-infected adults receiving medical care in the U.S. did not engage in sexual risk behaviours that have the potential to transmit HIV, and of the 12% who did, approximately half were not virally suppressed. Persons who were virally suppressed were less likely than persons who were not suppressed to engage in sexual risk behaviours.

The role of viral introductions in sustaining community-based HIV epidemics in rural Uganda: evidence from spatial clustering, phylogenetics, and egocentric transmission models

BACKGROUND

It is often assumed that local sexual networks play a dominant role in HIV spread in sub-Saharan Africa. The aim of this study was to determine the extent to which continued HIV transmission in rural communities--home to two-thirds of the African population--is driven by intra-community sexual networks versus viral introductions from outside of communities.

METHODS AND FINDINGS

We analyzed the spatial dynamics of HIV transmission in rural Rakai District, Uganda, using data from a cohort of 14,594 individuals within 46 communities. We applied spatial clustering statistics, viral phylogenetics, and probabilistic transmission models to quantify the relative contribution of viral introductions into communities versus community- and household-based transmission to HIV incidence. Individuals living in households with HIV-incident (n = 189) or HIV-prevalent (n = 1,597) persons were 3.2 (95% CI: 2.7-3.7) times more likely to be HIV infected themselves compared to the population in general, but spatial clustering outside of households was relatively weak and was confined to distances <500 m. Phylogenetic analyses of gag and env genes suggest that chains of transmission frequently cross community boundaries. A total of 95 phylogenetic clusters were identified, of which 44% (42/95) were two individuals sharing a household. Among the remaining clusters, 72% (38/53) crossed community boundaries. Using the locations of self-reported sexual partners, we estimate that 39% (95% CI: 34%-42%) of new viral transmissions occur within stable household partnerships, and that among those infected by extra-household sexual partners, 62% (95% CI: 55%-70%) are infected by sexual partners from outside their community. These results rely on the representativeness of the sample and the quality of self-reported partnership data and may not reflect HIV transmission patterns outside of Rakai.

CONCLUSIONS

Our findings suggest that HIV introductions into communities are common and account for a significant proportion of new HIV infections acquired outside of households in rural Uganda, though the extent to which this is true elsewhere in Africa remains unknown. Our results also suggest that HIV prevention efforts should be implemented at spatial scales broader than the community and should target key populations likely responsible for introductions into communities.

Expansion of HAART coverage is associated with sustained decreases in HIV/AIDS morbidity, mortality and HIV transmission: the "HIV Treatment as Prevention" experience in a Canadian setting

Background

There has been renewed call for the global expansion of highly active antiretroviral therapy (HAART) under the framework of HIV treatment as prevention (TasP). However, population-level sustainability of this strategy has not been characterized.

Methods

We used population-level longitudinal data from province-wide registries including plasma viral load, CD4 count, drug resistance, HAART use, HIV diagnoses, AIDS incidence, and HIV-related mortality. We fitted two Poisson regression models over the study period, to relate estimated HIV incidence and the number of individuals on HAART and the percentage of virologically suppressed individuals.

Results

HAART coverage, median pre-HAART CD4 count, and HAART adherence increased over time and were associated with increasing virological suppression and decreasing drug resistance. AIDS incidence decreased from 6.9 to 1.4 per 100,000 population (80% decrease, p = 0.0330) and HIV-related mortality decreased from 6.5 to 1.3 per 100,000 population (80% decrease, p = 0.0115). New HIV diagnoses declined from 702 to 238 cases (66% decrease; p = 0.0004) with a consequent estimated decline in HIV incident cases from 632 to 368 cases per year (42% decrease; p = 0.0003). Finally, our models suggested that for each increase of 100 individuals on HAART, the estimated HIV incidence decreased 1.2% and for every 1% increase in the number of individuals suppressed on HAART, the estimated HIV incidence also decreased by 1%.

Conclusions

Our results show that HAART expansion between 1996 and 2012 in BC was associated with a sustained and profound population-level decrease in morbidity, mortality and HIV transmission. Our findings support the long-term effectiveness and sustainability of HIV treatment as prevention within an adequately resourced environment with no financial barriers to diagnosis, medical care or antiretroviral drugs. The 2013 Consolidated World Health Organization Antiretroviral Therapy Guidelines offer a unique opportunity to further evaluate TasP in other settings, particularly within generalized epidemics, and resource-limited setting, as advocated by UNAIDS.

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.

Clinical uncertainties, health service challenges, and ethical complexities of HIV "test-and-treat": a systematic review

Despite the HIV "test-and-treat" strategy's promise, questions about its clinical rationale, operational feasibility, and ethical appropriateness have led to vigorous debate in the global HIV community. We performed a systematic review of the literature published between January 2009 and May 2012 using PubMed, SCOPUS, Global Health, Web of Science, BIOSIS, Cochrane CENTRAL, EBSCO Africa-Wide Information, and EBSCO CINAHL Plus databases to summarize clinical uncertainties, health service challenges, and ethical complexities that may affect the test-and-treat strategy's success. A thoughtful approach to research and implementation to address clinical and health service questions and meaningful community engagement regarding ethical complexities may bring us closer to safe, feasible, and effective test-and-treat implementation.

North-South Corridor Demonstration Project: Ethical and Logistical Challenges in the Design of a Demonstration Study of Early Antiretroviral Treatment for Long Distance Truck Drivers along a Transport Corridor through South Africa, Zimbabwe, and Zambia

Background. Long-distance truck drivers are at risk of acquiring and transmitting HIV and have suboptimal access to care. New HIV prevention strategies using antiretroviral drugs to reduce transmission risk (early antiretroviral therapy (ART) at CD4 count >350 cells/μL) have shown efficacy in clinical trials. Demonstration projects are needed to evaluate “real world” programme effectiveness. We present the protocol for a demonstration study to evaluate the feasibility, acceptability, and cost of an early ART intervention for HIV-positive truck drivers along a transport corridor across South Africa, Zimbabwe, and Zambia, as part of an enhanced strategy to improve treatment adherence and retention in care. Methods and Analysis. This demonstration study would follow an observational cohort of truck drivers receiving early treatment. Our mixed methods approach includes quantitative, qualitative, and economic analyses. Key ethical and logistical issues are discussed (i.e., choice of drug regimen, recruitment of participants, and monitoring of adherence, behavioural changes, and adverse events). Conclusion. Questions specific to the design of tailored early ART programmes are amenable to operational research approaches but present substantial ethical and logistical challenges. Addressing these in demonstration projects can inform policy decisions regarding strategies to reduce health inequalities in access to HIV prevention and treatment programmes.

Minimal interference: A basis for selecting ART for prevention with positives

Given international interest in "treatment as prevention" (TasP) and the pertinence of optimizing antiretroviral treatment (ART) regimens for TasP, 19 French HIV experts were interviewed on their criteria for ART if used specifically for prevention with HIV-positive persons. Through content analysis of the interview material, nine criteria were identified. The most endorsed criteria, collectively, suggest a choice of treatment based on "minimal interference" where negative impacts of ART are minimized and ease of treatment integration maximized in the lives of people living with HIV/AIDS (PLHIV) for both the short and long term. These criteria were the tolerance, side effects, and/or toxicity profile of ART, simplicity (e.g., of treatment schedule, dosage form) and the individualization of treatment (e.g., adapted to lifestyle). While virologic efficacy (i.e., a durable, undetectable viral load) was also deemed important, several experts specified that it was virtually assured with current treatments. To a much lesser extent, experts endorsed diffusion of ART into the genital compartments, a strong genetic barrier (against resistance), validated treatments (as opposed to new classes of ART), a rapid reduction in HIV viral load, and treatment cost. Pharmacologically, minimal interference calls for further improvements in the tolerance, side effects and toxicity profile of ART and in the simplicity of ART administration. Clinically, it means avoiding a one-size-fits-all approach to ART in TasP and engagement with and of PLHIV in ART selection and side effects management. Strategically, it emphasises keeping the health and quality of life of PLHIV at the forefront of a TasP-oriented public health intervention.

Human viral diseases: what is next for antiviral drug discovery?

For the treatment of human immunodeficiency virus (HIV) infections for which there are ample drugs available, the immediate future lies in a once-daily combination pill containing three or four active ingredients. This strategy may also be envisaged for the treatment of hepatitis C virus (HCV) infections as soon as we have at hand the appropriate direct-acting antiviral agents (DAAs) to be combined. A combination drug therapy is generally not entertained for other viruses. Yet, new drugs are at the horizon for the treatment of herpes simplex virus (HSV), varicella-zoster virus (VZV), poxvirus, hepatitis B virus (HBV), influenza and enveloped viruses-at-large.

Behavioral factors in assessing impact of HIV treatment as prevention

The recent NIH HPTN 052 study of using HIV treatment to prevent HIV transmission in serostatus discordant heterosexual partnerships has garnered much attention. In subsequent discussions, however, the topic of HIV-related risk behavior has been nearly absent. Here, we identify the critical roles that HIV-related risk behavior plays in determining the unmet needs, optimal targeting, and ultimate impact of treatment as prevention. We describe the size of the population at risk of HIV and three subgroups of persons living with HIV (PLWH) based on awareness of serostatus and risk behavior, and the corresponding HIV transmission rates to seronegative partners. For each of the subgroups of PLWH, we identify which approach is most relevant ("testing and linkage to care," "treatment as prevention," and/or "treatment as clinical care"). We observe that the impact of "treatment as prevention" on HIV incidence will depend heavily on which subgroup of PLWH is targeted for services.