Antiretroviral Therapy for the Prevention of HIV-1 Transmission

Viral Infections and Obesity

PURPOSE OF REVIEW

Obesity is a multifactorial disease that is now endemic throughout most of the world. Although addressing proximate causes of obesity (excess energy intake and reduced energy expenditure) have been longstanding global health priorities, the problem has continued to worsen at the global level.

RECENT FINDINGS

Numerous microbial agents cause obesity in various experimental models-a phenomena known as infectobesity. Several of the same agents alter metabolic function in human cells and are associated with human obesity or metabolic dysfunction in humans. We address the evidence for a role in the genesis of obesity for viral agents in five broad categories: adenoviridae, herpesviridae, phages, transmissible spongiform encephalopathies (slow virus), and other encephalitides and hepatitides. Despite the importance of this topic area, there are many persistent knowledge gaps that need to be resolved. We discuss factors motivating further research and recommend that future infectobesity investigation should be more comprehensive, leveraged, interventional, and patient-centered.

Tenofovir alafenamide, emtricitabine, elvitegravir, and cobicistat combination therapy for the treatment of HIV

INTRODUCTION

Tenofovir alafenamide (TAF) is a novel prodrug of the nucleotide analogue reverse-transcriptase inhibitor, tenofovir. TAF has been co-formulated with emtricitabine (FTC), elvitegravir (EVG) and the EVG metabolic enhancer, cobicistat (COBI) as a single-tablet regimen being the first TAF-containing antiretroviral combination available. Areas covered: This article summarizes the available information on the pharmacology of the novel compound TAF and overviews TAF/FTC/EVG/COBI use for HIV-1 infected patients, with specific focus on clinical efficacy and safety data. Information sources include peer-reviewed scientific literature, conference proceedings and publically available regulatory reports. Compared to tenofovir disoproxil fumarate, TAF results in higher concentrations of the active metabolite tenofovir diphosphate within lymphoid cells, whereas plasma tenofovir exposure is about 90% lower. The efficacy and safety of TAF/FTC/EVG/COBI in treatment-naïve HIV-infected patients has been assessed in phase-III randomized trials, showing non-inferior virological suppression in comparison with TDF/FTC/EVG/COBI, and significantly lower renal and bone toxicity. In addition, TAF/FTC/EVG/COBI has demonstrated efficacy and safety as a switching strategy in suppressed HIV-1 infected individuals, including those with mild or moderate renal impairment. Expert commentary: Approval of the single-tablet TAF/FTC/EVG/COBI regimen is an important advance in HIV therapy, as it is associated with very high efficacy and a better kidney and bone safety profile compared to TDF-containing regimens due to the incorporation of TAF.

Pre-exposure prophylaxis prescribing and retention in care among heterosexual women at a community-based comprehensive sexual health clinic

In the United States, heterosexual women account for 20% of new HIV infections. As a user-controlled HIV prevention method, pre-exposure prophylaxis (PrEP) has substantial potential to reduce new infections among women. However, among women, PrEP is vastly underutilized. To guide efforts to increase women-at-risk's PrEP use, we sought to describe the characteristics of women prescribed PrEP as well as their retention in PrEP care. We conducted a chart review of women who received care at a comprehensive sexual health clinic within a large urban health care system. Referral sources included the health care system's clinics and HIV testing program, as well as local community-based organizations. From 1 December 2014 to 5 August 2016, 554 women received care at the clinic. During this period, 21 heterosexual women (3.8%) received at least one prescription for daily oral PrEP. For women prescribed PrEP, median age was 35 years old (range: 20-52). The majority (66.7%) were either Latina or non-Latina Black and most (81.2%) had public health insurance. The most common PrEP indication was being in a known sero-discordant partnership (85.7%). Of women in such partnerships, 83.3% reported their male partner was currently taking antiretroviral medications (ARVs) and 16.7% reported trying to conceive with their partner (not mutually exclusive). Of women with ARV-using partners, 66.7% reported that their partners were virally suppressed. Retention in PrEP care at three months was 61.1% and, at six months, 37.5%. Further study is necessary to expand PrEP to women whose risk factors extend beyond being in a known sero-discordant partnership, and to understand the reasons for the observed drop-off in PrEP care visits in real-world settings.

The Risk of Sexually Transmitted Infection and Its Influence on Condom Use among Pregnant Women in the Kintampo North Municipality of Ghana

Sexually transmitted infection (STI) affects the reproductive health of both men and women worldwide. Condoms are important part of the available preventive strategies for STI control. The lack of proper risk-perception continues to impede women's ability to negotiate condom use with their partners. This paper is the outcome of secondary analysis of data collected in a cross-sectional survey that explored the perception of risk of STI and its influence on condom use among 504 pregnant women attending antenatal clinic at two health facilities in the Kintampo North Municipality. Consecutively, three Focus Group Discussions were conducted among 22 pregnant women which was analyzed using thematic analysis technique. Multivariate logistic regression analysis was used to identify possible predictors of condom use and risk of STI. Respondents mean age was 26.0 ± 5.9 years. 47% of respondents self-identified themselves as high risk for contracting STI, 50% of whom were married. High risk status (OR = 2.1, 95% CI: 1.1-4.4), ability to ask for condoms during sex (OR = 0.3, 95% CI: 0.1-0.73), and partner's approval of condom use (OR = 0.2, 95% CI: 0.01-0.05) were independent predictors of condom use. Condom use (OR 2.9 (1.5-5.7); p = 0.001) and marital status (engaged, OR 2.6 (1.5-4.5); p = 0.001) were independent predictors of risk of STI. Women who self-identified themselves as high risk for STI successfully negotiated condom use with their partners. This is however influenced by partner's approval and ability to convince partner to use condoms. Self-assessment of STI risk by women and the cooperation of male partners remain critical.

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.

Basis and Statistical Design of the Passive HIV-1 Antibody Mediated Prevention (AMP) Test-of-Concept Efficacy Trials

BACKGROUND

Anti-HIV-1 broadly neutralizing antibodies (bnAbs) have been developed as potential agents for prevention of HIV-1 infection. The HIV Vaccine Trials Network and the HIV Prevention Trials Network are conducting the Antibody Mediated Prevention (AMP) trials to assess whether, and how, intravenous infusion of the anti-CD4 binding site bnAb, VRC01, prevents HIV-1 infection. These are the first test-of-concept studies to assess HIV-1 bnAb prevention efficacy in humans.

METHODS

The AMP trials are two parallel phase 2b HIV-1 prevention efficacy trials conducted in two cohorts: 2700 HIV-uninfected men and transgender persons who have sex with men in the United States, Peru, Brazil, and Switzerland; and 1500 HIV-uninfected sexually active women in seven countries in sub-Saharan Africa. Participants are randomized 1:1:1 to receive an intravenous infusion of 10 mg/kg VRC01, 30 mg/kg VRC01, or a control preparation every 8 weeks for a total of 10 infusions. Each trial is designed (1) to assess overall prevention efficacy (PE) pooled over the two VRC01 dose groups vs. control and (2) to assess VRC01 dose and laboratory markers as correlates of protection (CoPs) against overall and genotype- and phenotype-specific infection.

RESULTS

Each AMP trial is designed to have 90% power to detect PE > 0% if PE is ≥ 60%. The AMP trials are also designed to identify VRC01 properties (i.e., concentration and effector functions) that correlate with protection and to provide insight into mechanistic CoPs. CoPs are assessed using data from breakthrough HIV-1 infections, including genetic sequences and sensitivities to VRC01-mediated neutralization and Fc effector functions.

CONCLUSIONS

The AMP trials test whether VRC01 can prevent HIV-1 infection in two study populations. If affirmative, they will provide information for estimating the optimal dosage of VRC01 (or subsequent derivatives) and identify threshold levels of neutralization and Fc effector functions associated with high-level protection, setting a benchmark for future vaccine evaluation and constituting a bridge to other bnAb approaches for HIV-1 prevention.

Combination antiretroviral therapy and cancer risk

PURPOSE OF REVIEW

To review the newest research about the effects of combination antiretroviral therapy (cART) on cancer risk.

RECENT FINDINGS

HIV+ persons are at increased risk of cancer. As this risk is higher for malignancies driven by viral and bacterial coinfections, classifying malignancies into infection-related and infection-unrelated has been an emerging trend. Cohorts have detected major reductions in the incidence of Kaposi sarcoma and non-Hodgkin lymphoma (NHL) following cART initiation among immunosuppressed HIV+ persons. However, recent randomized data indicate that cART reduces risk of Kaposi sarcoma and NHL also during early HIV infection before overt immunosuppression occurs. Long-term effects of cART exposure on cancer risk are not well defined; according to basic and epidemiological research, there might be specific associations of each cART class with distinct patterns of cancer risk.

SUMMARY

The relationship between cART exposure and cancer risk is complex and nuanced. It is an intriguing fact that, whether initiated during severe immunosuppression or not, cART reduces risk of Kaposi sarcoma and NHL. Further research should identify mediators of the benefit of immediate cART initiation in reducing cancer risk, understand the relationship between long-term cART exposure and cancer incidence and assess whether adjuvant anti-inflammatory therapies can reduce cancer risk during treated HIV infection.

A longitudinal cohort study of HIV 'treatment as prevention' in gay, bisexual and other men who have sex with men: the Treatment with Antiretrovirals and their Impact on Positive And Negative men (TAIPAN) study protocol

BACKGROUND

Australia has increased coverage of antiretroviral treatment (ART) over the past decade, reaching 73% uptake in 2014. While ART reduces AIDS-related deaths, accumulating evidence suggests that it could also bolster prevention efforts by reducing the risk of HIV transmission ('treatment as prevention'). While promising, evidence of community-level impact of treatment as prevention on reducing HIV incidence among gay and bisexual men is limited. We describe a study protocol that aims to determine if scale up of testing and treatment for HIV leads to a reduction in community viraemia and, in turn, if this reduction is temporally associated with a reduction in HIV incidence among gay and bisexual men in Australia's two most populous states.

METHODS

Over the period 2009 to 2017, we will establish two cohorts making use of clinical and laboratory data electronically extracted retrospectively and prospectively from 73 health services and laboratories in the states of New South Wales and Victoria. The 'positive cohort' will consist of approximately 13,000 gay and bisexual men (>90% of all people living with HIV). The 'negative cohort' will consist of at least 40,000 HIV-negative gay and bisexual men (approximately half of the total population). Within the negative cohort we will use standard repeat-testing methods to calculate annual HIV incidence. Community prevalence of viraemia will be defined as the proportion of men with a viral load ≥200RNA copies/mm³, which will combine viral load data from the positive cohort and viraemia estimates among those with an undiagnosed HIV infection. Using regression analyses and adjusting for behavioural and demographic factors associated with infection, we will assess the temporal association between the community prevalence of viraemia and the incidence of HIV infection. Further analyses will make use of these cohorts to assess incidence and predictors of treatment initiation, repeat HIV testing, and viral suppression.

DISCUSSION

This study will provide important information on whether 'treatment as prevention' is associated with a reduction in HIV incidence at a community level among gay and bisexual men.

"Since both of us are using antiretrovirals, we have been supportive to each other": facilitators and barriers of pre-exposure prophylaxis use in heterosexual HIV serodiscordant couples in Kisumu, Kenya

Introduction

Since 2015, the World Health Organization recommends pre-exposure prophylaxis (PrEP) for all persons at substantial risk for HIV, including HIV-uninfected partners in serodiscordant relationships in resource-limited settings. As PrEP moves from clinical trials to real-world use, understanding facilitators of and barriers to PrEP initiation and adherence is critical to successful PrEP implementation and rollout.

Methods

We conducted 44 in-depth individual or couple interviews with 63 participants (30 without HIV and 33 with HIV) enrolled in the Partners Demonstration Project in Kisumu, Kenya, between August and September 2014. The semi-structured interviews discussed the following: 1) perceived advantages and disadvantages of antiretroviral therapy (ART)/PrEP; 2) reasons for accepting or declining ART/PrEP and 3) influence of prevention of transmission to partner or infant on ART/PrEP use. Transcripts from the interviews were iteratively analyzed using inductive content analysis.

Results

Our study identified three key factors that may facilitate initiation of PrEP in this population. First, participants using PrEP felt reduced stress and increased trust in their HIV serodiscordant relationships. Second, greater community-wide knowledge of PrEP was thought to likely increase PrEP acceptance. Third, greater education and counselling by providers on PrEP use was also considered to likely increase the adoption of PrEP. We also identified three key barriers to initiation of and adherence to PrEP. First, most participants who declined PrEP expressed doubts about the relative additional effectiveness of PrEP in combination with other prevention tools. Second, perceived stigma related to PrEP use was an important barrier to PrEP initiation. Third, many struggled with overcoming perceived side effects or logistical challenges of taking daily PrEP, particularly when they themselves were not ill.

Conclusions

Leveraging the facilitators and overcoming barriers to PrEP uptake may enhance the successful rollout of PrEP among HIV serodiscordant couples in Kenya and other areas in sub-Saharan Africa, thereby reducing sexual transmission of HIV. Further research focused on how best to provide counselling on combination HIV prevention tools in the context of PrEP use is a crucial next step to delivering PrEP.

Fixed-dose combination emtricitabine/tenofovir/efavirenz initiated during acute HIV infection; 96-week efficacy and durability

BACKGROUND

Updated guidelines recommend immediate antiretroviral treatment (ART) during acute HIV infection (AHI), but efficacy data on regimens during AHI are limited.

METHODS

We provide final data on a prospective, single-arm 96-week open-label study of once-daily emtricitabine/tenofovir/efavirenz initiated during AHI. The primary endpoint was the proportion of responders with HIV RNA less than 200 copies/ml by week 24. We examined time to viral suppression, retention, and CD8 cell activation through week 96 in relation to baseline characteristics.

RESULTS

Between January 2005 and December 2011, 92 AHI participants enrolled. Most participants (78%) were men who have sex with men (MSM), and 42% were young MSM (18-25 years of age). Two participants withdrew leaving 90 patients for analysis. Eighty-one (90%) remained on therapy and achieved viral suppression to less than 200 copies/ml by week 24, and 71 (79%) to less than 50 copies/ml at week 48. The median time from ART initiation to suppression less than 200 copies/ml was 65 days (range 7-523) and to less than 50 copies/ml was 105 days (range 14-523). The frequency of immune activation declined from a median of 67% to 16% through week 96. Retention on study was maintained in 92% of participants at week 48 and in 83% through week 96. Among 75 participants retained through week 96, 92% were suppressed to less than 50 copies/ml. Among 39 young MSM, 79% completed a week 96 visit and 67% were suppressed at week 96.

CONCLUSION

ART during AHI resulted in rapid and sustained viral suppression with high rates of retention in care and on ART in this cohort including a large proportion of young MSM.

Using Population-Size Estimation and Cross-sectional Survey Methods to Evaluate HIV Service Coverage Among Key Populations in Burkina Faso and Togo

OBJECTIVES

The objective of our study was to measure progress toward the UNAIDS 90-90-90 HIV care targets among key populations in urban areas of 2 countries in West Africa: Burkina Faso and Togo.

METHODS

We recruited female sex workers (FSWs) and men who have sex with men (MSM) through respondent-driven sampling. From January to July 2013, 2738 participants were enrolled, tested for HIV, and completed interviewer-administered surveys. We used population-size estimation methods to calculate the number of people who were engaged in the HIV continuum of care.

RESULTS

HIV prevalence ranged from 0.6% (2 of 329) of MSM in Kara, Togo, to 32.9% (115 of 350) of FSWs in Bobo Dioulasso, Burkina Faso. Of those confirmed to be HIV infected, a range of 0.0% (0 of 2) of MSM in Kara to 55.7% (64 of 115) of FSWs in Bobo Dioulasso were using ART. Based on population estimates, the percentage gap between HIV-infected people who should be using ART (per the 90-90-90 targets) and those who reported using ART ranged from 31.5% among FSWs in Bobo Dioulasso to 100.0% among MSM in Kara.

CONCLUSIONS

HIV service coverage among MSM and FSWs in Burkina Faso and Togo was low in 2013. Interventions for improving engagement of these at-risk populations in the HIV continuum of care should include frequent, routine HIV testing and linkage to evidence-based HIV treatment services. Population-size estimates can be used to inform governments, policy makers, and funding agencies about where elements of HIV service coverage are most needed.

Risk Factor Associated with Negative Spouse HIV Seroconversion among Sero-Different Couples: A Nested Case-Control Retrospective Survey Study in 30 Counties in Rural China

Background

Antiretroviral therapy (ART) and condom use have been proven to reduce the risk of sexual transmission of human immunodeficiency virus (HIV) among HIV sero-different couples, but its full implementation remains a challenge. This study aims to assess HIV seroconversion rate of HIV-negative spouse and its associated risk factors among HIV sero-different couples in rural China.

Methods

An open cohort of HIV sero-different couples enrolled in 30 counties in China between October 1, 2010, and September 30, 2012, and followed-up to December 31, 2012, was constructed retrospectively. A nested case-control study of risk factors of HIV seroconversion among sero-different couples was conducted in April and May of 2013, based on the open cohort. Sero-different couples with the HIV-negative spouse seroconverting at least 3 months after the previous negative diagnosis during cohort observation period were labeled as “case couples”. The “control couples” were selected randomly from the same cohort that did not have the HIV-negative spouse seroconversion during the same period. The “case couples” and “control couples” were matched on gender, age, and region of residence. Sexual behaviors among HIV sero-different couples before and after the index spouses notifying their HIV infection status to their HIV-negative spouses were collected via face-to-face interview. Univariate and multivariate logistic regression models were used to assess factors associated with HIV seroconversion among HIV sero-different couples.

Results

Of 4481 HIV sero-different couples, a total of 53 seroconversions were observed within 5218 person-years of follow-up. The incidence rate was 1.02 (95%CI: 0.76–1.33) per 100 person-years. Forty “case couples” confirmed HIV-negative spouse seroconversions infected via marital sexual transmission, were matched to 80 “control couples”. Of the 120 couples, 81(67.5%) were receiving ART, and 70 (58.3%) reported consistently used condoms during intercourse after the index spouse was diagnosed HIV infection. Multivariate conditional logistic regression analysis showed that the desire to conceive a child (OR = 5.18, 95% CI: 1.19–22.58) significantly increased the odds of HIV seroconversion. Protective factors of spousal HIV seroconversion were currently receiving ART (OR = 0.09, 95% CI: 0.01–0.67) and consistent condom use (OR = 0.05, 95% CI: 0.01–0.28).

Conclusions

Intention to conceive a child is the most important risk factor for HIV seroconversion among sero-different couples. Specific efforts on scientific use of ART to assist sero-different couples to achieve their wish to conceive a healthy child are needed to minimize the risk of HIV transmission.

What Community-Based HIV Prevention Organizations Say About Their Role in Biomedical HIV Prevention

Community-based organizations (CBOs) are critical to delivery of effective HIV prevention because of their reach to key populations. This online survey of a national sample of CBOs assessed their awareness of, interest in, and resources needed to provide nonoccupational postexposure prophylaxis (nPEP), preexposure prophylaxis (PrEP), and HIV treatment as prevention (TasP). One hundred seventy-five CBOs participated: 87 clinical and 88 nonclinical CBOs. For nPEP, PrEP, and TasP, program managers reported that awareness was high (94%, 90%, 85%), meeting current client need was low (20%, 13%, 18%), and the likelihood of increasing their current provision with additional resources was somewhat high (62%, 64%, 62%). Clinical CBOs were more prepared to support expansion of these biomedical interventions than nonclinical CBOs. Meeting the information, training, and resource needs of CBOs is critical for effective collaboration to reduce the number of new HIV infections through expanded delivery of PrEP, nPEP, and TasP.