HIV treatment as prevention: optimising the impact of expanded HIV treatment programmes

CXCR4 Targeting Nanoplatform for Transcriptional Activation of Latent HIV-1 Infected T Cells

Antiretroviral drugs are limited in their ability to target latent retroviral reservoirs in CD4+ T cells, highlighting the need for a T cell-targeted drug delivery system that activates the transcription of inactivated viral DNA in infected cells. Histone deacetylase inhibitors (HDACi) disrupt chromatin-mediated silencing of the viral genome and are explored in HIV latency reversal. But single drug formulations of HDACi are insufficient to elicit therapeutic efficacy, warranting combination therapy. Furthermore, protein kinase C activators (PKC) have shown latency reversal activity in HIV by activating the NF-κB signaling pathway. Combining HDACi (SAHA) with PKC (PMA) activators enhances HIV reservoir activation by promoting chromatin decondensation and subsequent transcriptional activation. In this study, we developed a mixed nanomicelle (PD-CR4) drug delivery system for simultaneous targeting of HIV-infected CD4+ T cells with two drugs, suberoylanilide hydroxamic acid (SAHA) and phorbol 12-myristate 13-acetate (PMA). SAHA is a HDACi that promotes chromatin decondensation, while PMA is a PKC agonist that enhances transcriptional activation. The physicochemical properties of the formulated PD-CR4 nanoparticles were characterized by NMR, CMC, DLS, and TEM analyses. Further, we investigated in vitro safety profiles, targeting efficacy, and transcriptional activation of inactivated HIV reservoir cells. Our results suggest that we successfully prepared a targeted PD system with dual drug loading. We have compared latency reversal efficacy of a single drug nanoformulation and combination drug nanoformulation. Final PD-SP-CR4 successfully activated infected CD4+ T cell reservoirs and showed enhanced antigen release from HIV reservoir T cells, compared with the single drug treatment group as expected. To summarize, our data shows PD-SP-CR4 has potential T cell targeting efficiency and efficiently activated dormant CD4+ T cells. Our data indicate that a dual drug-loaded particle has better therapeutic efficacy than a single loaded particle as expected. Hence, PD-CR4 can be further explored for HIV therapeutic drug delivery studies.

Historical visit attendance as predictor of treatment interruption in South African HIV patients: Extension of a validated machine learning model

Retention of antiretroviral (ART) patients is a priority for achieving HIV epidemic control in South Africa. While machine-learning methods are being increasingly utilised to identify high risk populations for suboptimal HIV service utilisation, they are limited in terms of explaining relationships between predictors. To further understand these relationships, we implemented machine learning methods optimised for predictive power and traditional statistical methods. We used routinely collected electronic medical record (EMR) data to evaluate longitudinal predictors of lost-to-follow up (LTFU) and temporal interruptions in treatment (IIT) in the first two years of treatment for ART patients in the Gauteng and North West provinces of South Africa. Of the 191,162 ART patients and 1,833,248 visits analysed, 49% experienced at least one IIT and 85% of those returned for a subsequent clinical visit. Patients iteratively transition in and out of treatment indicating that ART retention in South Africa is likely underestimated. Historical visit attendance is shown to be predictive of IIT using machine learning, log binomial regression and survival analyses. Using a previously developed categorical boosting (CatBoost) algorithm, we demonstrate that historical visit attendance alone is able to predict almost half of next missed visits. With the addition of baseline demographic and clinical features, this model is able to predict up to 60% of next missed ART visits with a sensitivity of 61.9% (95% CI: 61.5-62.3%), specificity of 66.5% (95% CI: 66.4-66.7%), and positive predictive value of 19.7% (95% CI: 19.5-19.9%). While the full usage of this model is relevant for settings where infrastructure exists to extract EMR data and run computations in real-time, historical visits attendance alone can be used to identify those at risk of disengaging from HIV care in the absence of other behavioural or observable risk factors.

Factors Associated with Health Care Providers' Preference for Forgoing an Oral Lead-In Phase When Initiating Long-Acting Injectable Cabotegravir and Rilpivirine in the SOLAR Clinical Trial

Cabotegravir and rilpivirine long-acting (LA) antiretroviral therapy (ART) demonstrated similar safety and efficacy in maintaining viral suppression among participants switching from daily oral to LA ART in the Extension Phase of the FLAIR trial. The Phase IIIb SOLAR study comparing efficacy and safety of daily oral versus LA ART every 2 months allowed participants and health care providers (HCPs) to choose an oral lead-in (OLI) before LA initiation or proceed by immediately starting with injections (SWI). We conducted an online survey among SOLAR HCPs (n = 110) in 13 countries to assess reasons for choosing OLI versus SWI. Logistic regression was used to identify factors influencing this decision. Thirty-two percent of HCPs reported a future preference to use OLI, whereas 54% reported a future preference for SWI. HCPs had greater odds of reporting future intentions for SWI if they were from Continental Europe versus North America [adjusted odds ratio (aOR): 3.83, p < 0.05], from sites with a greater number of participants who initiated LA ART without OLI (aOR: 1.56, p < 0.01), and those who reported comfort with the medication safety profile (aOR: 6.39, p < 0.01). HCPs who participated in LA ART trials before SOLAR had decreased odds of reporting a preference for SWI compared to those with no prior LA ART trial experience (aOR: 0.11; p < 0.01). Results indicated higher intentions to SWI over OLI among HCPs initiating participants on LA ART. A major factor associated with SWI was provider comfort with safety data, reinforcing the role of continued training regarding an SWI approach.

High Level of HIV Drug Resistance and Virologic Nonsuppression Among Female Sex Workers in Ethiopia: A Nationwide Cross-Sectional Study

OBJECTIVE

To determine viral load (VL) nonsuppression (VLN) rates, HIV drug resistance (HIVDR) prevalence, and associated factors among female sex workers (FSWs) in Ethiopia.

METHODS

A cross-sectional biobehavioral survey was conducted among FSWs in 11 cities in Ethiopia in 2014. Whole blood was collected, and HIVDR genotyping was performed. Logistic regression analysis was performed to identify factors associated with VLN and HIVDR.

RESULTS

Among 4900 participants, 1172 (23.9%) were HIV-positive and 1154 (98.5%) had a VL result. Participants were categorized into antiretroviral therapy (ART) (n = 239) and ART-naive (n = 915) groups based on self-report. From the 521 specimens (ART, 59; ART-naive, 462) with VL ≥1000 copies/mL, genotyping was successful for 420 (80.6%) and 92 (21.9%) had drug resistance mutations (DRMs). Pretreatment drug resistance (PDR) was detected in 16.5% (63/381) of the ART-naive participants. Nucleoside reverse transcriptase inhibitor (NRTI), non-NRTIs (NNRTIs), and dual-class DRMs were detected in 40 (10.5%), 55 (14.4%), and 35 (9.2%) of the participants, respectively. Among 239 participants on ART, 59 (24.7%) had VLN. Genotyping was successfully performed for 39 (66.1%). DRMs were detected in 29 (74.4%). All 29 had NNRTI, 23 (79.3%) had NRTI or dual-class DRMs. VLN was associated with age 35 years or older, CD4+ T-cell count <350 cells/mm3, and being forced into selling sex. PDR and acquired drug resistance were associated with CD4+ T-cell count <350 cells/mm3 (P < 0.001).

CONCLUSIONS

The high VLN and HIVDR rates among FSWs underscore the need for targeted interventions to improve ART access and virologic monitoring to maximize the benefit of ART and limit the spread of HIV and HIVDR.

Assessing the Relationship Between HIV Quality of Care and Treatment Literacy on ART Adherence and Viral Suppression Among Female Sex Workers Living in the Dominican Republic

This study assessed the relationship between the quality of HIV care and treatment literacy on antiretroviral therapy (ART) adherence and viral suppression among female sex workers (FSWs) living with HIV (n = 211) in Santo Domingo, Dominican Republic. Multivariable logistic regression results indicate better patient-provider communication (AOR 1.04; 95% CI 1.01-1.07) and respectful treatment (AOR 2.17; 95% CI 1.09-4.32) increase the odds of viral suppression, while higher costs reduce both the odds of ART adherence (AOR 0.57, 95% CI 0.34- 0.95) and being virally suppressed (AOR 0.59, 95% CI 0.41-0.85). Greater treatment literacy was associated with an increased odds of ART adherence (AOR 4.15 for understanding of viral load; 95% CI 1.50-11.52) and viral suppression (AOR 2.75 for understanding of CD4 count; 95% CI 1.31-5.80). Findings support investments in treatment education, effective and respectful patient-provider communication, dignified care, and cost-support for associated HIV care costs to facilitate FSWs' pathway towards viral suppression.

Immunogenetic determinants of heterosexual HIV-1 transmission: key findings and lessons from two distinct African cohorts

Immunogenetic studies in the past three decades have uncovered a broad range of human genetic factors that seem to influence heterosexual HIV-1 transmission in one way or another. In our own work that jointly evaluated both genetic and nongenetic factors in two African cohorts of cohabiting, HIV-1-discordant couples (donor and recipient pairs) at risk of transmission during quarterly follow-up intervals, relatively consistent findings have been seen with three loci (IL19, HLA-A, and HLA-B), although the effect size (i.e., odds ratio or hazards ratio) of each specific variant was quite modest. These studies offered two critical lessons that should benefit future research on sexually transmitted infections. First, in donor partners, immunogenetic factors (e.g., HLA-B*57 and HLA-A*36:01) that operate directly through HIV-1 viral load or indirectly through genital coinfections are equally important. Second, thousands of single-nucleotide polymorphisms previously recognized as "causal" factors for human autoimmune disorders did not appear to make much difference, which is somewhat puzzling as these variants are predicted or known to influence the expression of many immune response genes. Replicating these observations in additional cohorts is no longer feasible as the field has shifted its focus to early diagnosis, universal treatment, and active management of comorbidities.

Treatment as Prevention: Concepts and Challenges for Reducing HIV Incidence

Four of the largest HIV prevention trials have been conducted in sub-Saharan Africa, enrolling hundreds of thousands of participants in catchment areas of millions of people. The trials have focused on community-level interventions to increase diagnosis and initiation of antiretroviral therapy (ART) to improve health and reduce HIV transmission. Universal test-and-treat strategies are deployed to achieve viral suppression thereby reducing risk to uninfected persons, known as treatment as prevention (TasP).

A Qualitative Exploration of Family, Work, Community, and Health Service Influences on HIV Treatment Uptake and Adherence Among Female Sex Workers in Three Cities in Indonesia

Qualitative data were collected from 34 Indonesian female sex workers to understand their engagement with HIV treatment. Influences that enhanced treatment initiation and adherence included women's desires to stay healthy to continue working to provide for families; awareness of the biomedical benefits of treatment; support from bosses, outreach workers, and peer support groups; and flexible, nonjudgmental HIV service provision. Influences inhibiting treatment initiation and adherence included concerns about unwanted disclosure in the workplace and side effects of medication on women's capacity to earn money through sex work; geographical location of services; discrimination and confidentiality concerns in HIV care services. To improve HIV treatment initiation and adherence among Indonesian female sex workers, future responses should explore health promotion messages that engage with women's family and livelihood obligations; increased funding for community-based peer outreach workers; community-based treatment initiation and supply; and advocacy in work environments to secure support for treatment initiatives.

Predictors of lost to follow-up in a "test and treat" programme among adult women with high-risk sexual behavior in Kampala, Uganda

BACKGROUND

Immediate uptake of antiretroviral therapy (ART) after an HIV-positive diagnosis (Test and Treat) is now being implemented in Uganda. Data are limited on lost to follow-up (LTFU) in high-risk cohorts that have initiated 'Test and Treat'. We describe LTFU in a cohort of women of high-risk sexual behaviour who initiated ART under "Test and Treat".

METHODS

We performed a retrospective cohort study of participant records at the Good Health for Women Project (GHWP) clinic, a clinic in Kampala for women at high-risk of HIV-infection. We included HIV positive women ≥18 years who initiated ART at GHWP between August 2014 and March 2018. We defined LTFU as not taking an ART refill for ≥3 months from the last clinic appointment among those not registered as dead or transferred to another clinic. We used the Kaplan-Meier technique to estimate time to LTFU after ART initiation. Predictors of LTFU were assessed using a multivariable Cox proportional hazards model.

RESULTS

The mean (±SD) age of the 293 study participants was 30.3 (± 6.5) years, with 274 (94%) reporting paid sex while 38 (13%) had never tested for HIV before enrolment into GHWP. LTFU within the first year of ART initiation was 16% and the incidence of LTFU was estimated at 12.7 per 100 person-years (95%CI 9.90-16.3). In multivariable analysis, participants who reported sex work as their main job at ART initiation (Adjusted Hazards Ratio [aHR] =1.95, 95%CI 1.10-3.45), having baseline WHO clinical stage III or IV (aHR = 2.75, 95% CI 1.30-5.79) were more likely to be LTFU.

CONCLUSION

LTFU in this cohort is high. Follow up strategies are required to support women on Test and Treat to remain on treatment, especially those who engage in sex work and those who initiate ART at a later stage of disease.

Cost-effectiveness of option B+ in prevention of mother-to-child transmission of HIV in Yunnan Province, China

BACKGROUND

Although Option B+ may be more costly than Options B, it may provide additional health benefits that are currently unclear in Yunnan province. We created deterministic models to estimate the cost-effectiveness of Option B+.

METHODS

Data were used in two deterministic models simulating a cohort of 2000 HIV+ pregnant women. A decision tree model simulated the number of averted infants infections and QALY acquired for infants in the PMTCT period for Options B and B+. The minimum cost was calculated. A Markov decision model simulated the number of maternal life year gained and serodiscordant partner infections averted in the ten years after PMTCT for Option B or B+. ICER per life year gained was calculated. Deterministic sensitivity analyses were conducted.

RESULTS

If fully implemented, Option B and Option B+ averted 1016.85 infections and acquired 588,01.02 QALYs.The cost of Option B was US$1,229,338.47, the cost of Option B+ was 1,176,128.63. However, when Options B and B+ were compared over ten years, Option B+ not only improved mothers'ten-year survival from 69.7 to 89.2%, saving more than 3890 life-years, but also averted 3068 HIV infections between serodiscordant partners. Option B+ yielded a favourable ICER of $32.99per QALY acquired in infants and $5149per life year gained in mothers. A 1% MTCT rate, a 90% coverage rate and a 20-year horizon could decrease the ICER per QALY acquired in children and LY gained in mothers.

CONCLUSIONS

Option B+ is a cost-effective treatment for comprehensive HIV prevention for infants and serodiscordant partners and life-long treatment for mothers in Yunnan province, China. Option B+ could be implemented in Yunnan province, especially as the goals of elimination mother-to-child transmission of HIV and "90-90-90" achieved, Option B+ would be more attractive.

Using Contact Patterns to Inform HIV Interventions in Persons Who Inject Drugs in Northern Vietnam

OBJECTIVES

Population mixing patterns can greatly inform allocation of HIV prevention interventions such as treatment as prevention or preexposure prophylaxis. Characterizing contact patterns among subgroups can help identify the specific combinations of contact expected to result in the greatest number of new infections.

SETTING

Baseline data from an intervention to reduce HIV-related risk behaviors in male persons who inject drugs (PWID) in the Northern Vietnamese province of Thai Nguyen were used for the analysis.

METHODS

Egocentric network data were provided by PWID who reported any drug-injection equipment sharing in the previous 3 months. Age-dependent mixing was assessed to explore its epidemiological implications on risk of HIV transmission risk (among those HIV-infected) and HIV acquisition risk (among those not infected) in PWID.

RESULTS

A total of 1139 PWID collectively reported 2070 equipment-sharing partnerships in the previous 3 months. Mixing by age identified the 30-34 and 35-39 years age groups as the groups from whom the largest number of new infections was transmitted, making them primary targets for treatment as prevention. Among the uninfected, 25-29, 30-35, and 35-39 years age groups had the highest HIV acquisition rate, making them the primary targets for preexposure prophylaxis.

CONCLUSIONS

Collection and analysis of contact patterns in PWID is feasible and can greatly inform infectious disease dynamics and targeting of appropriate interventions. Results presented also provide much needed empirical data on mixing to improve mathematical models of disease transmission in this population.

A primer on multiscale modelling of infectious disease systems

The development of multiscale models of infectious disease systems is a scientific endeavour whose progress depends on advances on three main frontiers: (a) the conceptual framework frontier, (b) the mathematical technology or technical frontier, and (c) the scientific applications frontier. The objective of this primer is to introduce foundational concepts in multiscale modelling of infectious disease systems focused on these three main frontiers. On the conceptual framework frontier we propose a three-level hierarchical framework as a foundational idea which enables the discussion of the structure of multiscale models of infectious disease systems in a general way. On the scientific applications frontier we suggest ways in which the different structures of multiscale models can serve as infrastructure to provide new knowledge on the control, elimination and even eradication of infectious disease systems, while on the mathematical technology or technical frontier we present some challenges that modelers face in developing appropriate multiscale models of infectious disease systems. We anticipate that the foundational concepts presented in this primer will be central in articulating an integrated and more refined disease control theory based on multiscale modelling - the all-encompassing quantitative representation of an infectious disease system.

Do female sex workers have lower uptake of HIV treatment services than non-sex workers? A cross-sectional study from east Zimbabwe

OBJECTIVE

Globally, HIV disproportionately affects female sex workers (FSWs) yet HIV treatment coverage is suboptimal. To improve uptake of HIV services by FSWs, it is important to identify potential inequalities in access and use of care and their determinants. Our aim is to investigate HIV treatment cascades for FSWs and non-sex workers (NSWs) in Manicaland province, Zimbabwe, and to examine the socio-demographic characteristics and intermediate determinants that might explain differences in service uptake.

METHODS

Data from a household survey conducted in 2009-2011 and a parallel snowball sample survey of FSWs were matched using probability methods to reduce under-reporting of FSWs. HIV treatment cascades were constructed and compared for FSWs (n=174) and NSWs (n=2555). Determinants of service uptake were identified a priori in a theoretical framework and tested using logistic regression.

RESULTS

HIV prevalence was higher in FSWs than in NSWs (52.6% vs 19.8%; age-adjusted OR (AOR) 4.0; 95% CI 2.9 to 5.5). In HIV-positive women, FSWs were more likely to have been diagnosed (58.2% vs 42.6%; AOR 1.62; 1.02-2.59) and HIV-diagnosed FSWs were more likely to initiate ART (84.9% vs 64.0%; AOR 2.33; 1.03-5.28). No difference was found for antiretroviral treatment (ART) adherence (91.1% vs 90.5%; P=0.9). FSWs' greater uptake of HIV treatment services became non-significant after adjusting for intermediate factors including HIV knowledge and risk perception, travel time to services, physical and mental health, and recent pregnancy.

CONCLUSION

FSWs are more likely to take up testing and treatment services and were closer to achieving optimal outcomes along the cascade compared with NSWs. However, ART coverage was low in all women at the time of the survey. FSWs' need for, knowledge of and proximity to HIV testing and treatment facilities appear to increase uptake.

A Prospective Study of Intimate Partner Violence as a Risk Factor for Detectable Plasma Viral Load in HIV-Positive Women Engaged in Transactional Sex in Mombasa, Kenya

We conducted a prospective cohort study to evaluate intimate partner violence (IPV) as a risk factor for detectable plasma viral load in HIV-positive female sex workers (FSWs) on antiretroviral therapy (ART) in Kenya. IPV in the past year was defined as ≥1 act of physical, sexual, or emotional violence by the index partner (i.e. boyfriend/husband). The primary outcome was detectable viral load (≥180 copies/ml). In-depth interviews and focus groups were included to contextualize results. Analyses included 195 women (570 visits). Unexpectedly, IPV was associated with significantly lower risk of detectable viral load (adjusted relative risk 0.21, 95 % CI 0.05-0.84, p-value = 0.02). Qualitative findings revealed that women valued emotional and financial support from index partners, despite IPV. IPV was not a major barrier to ART adherence. The observed association between IPV and lower risk of detectable viral load in FSWs may be due to unmeasured personal and relationship factors, warranting further research.

Effect of pre-exposure prophylaxis and combination HIV prevention for men who have sex with men in the UK: a mathematical modelling study

BACKGROUND

HIV transmission in men who have sex with men (MSM) in the UK has shown no sign of decreasing in the past decade. Additional prevention measures are needed. We aimed to estimate the effect of various potential interventions implemented individually and in combination on prevention of HIV infection.

METHODS

We extended a deterministic partnership-based mathematical model for HIV transmission, informed by detailed behavioural and surveillance data, to assess the effect of seven different HIV interventions implemented in MSM (aged 15-64 years) in the UK during 2014-20, including increasing rates of HIV testing, test-and-treat programmes, pre-exposure prophylaxis (PrEP), and sexual behavioural changes. We did sensitivity analyses on risk compensation.

FINDINGS

We predicted a baseline of 16 955 new infections (IQR 13 156-21 669) in MSM in the UK during 2014-20. At a coverage of ≤50%, testing twice a year outperformed all other interventions. Of all intervention combinations, only the combined effect of test and treat and annual HIV testing (61·8%, IQR 47·2-81·8, of total incidence) was greater than the sum of effects of the two interventions individually (32·6%, 23·7-46·0, and 23·9%, 16·5-33·3, respectively). Simultaneous PrEP, expansion of HIV testing, and initiation of test-and-treat programme in 25% of high-activity MSM could save 7399 (IQR 5587-9813) UK MSM from HIV infection (43·6%, IQR 32·9-57·9, of total incidence). An increase in unsafe sex or sexual partners to 50% or more could substantially reduce the effect of interventions, but is unlikely to negate the prevention benefit completely.

INTERPRETATION

PrEP could prevent a large number of new HIV infections if other key strategies including HIV testing and treatment are simultaneously expanded and improved. Without PrEP, HIV incidence in MSM in the UK is unlikely to decrease substantially by the end of this decade.

FUNDING

Health Protection Agency (now Public Health England).

The HIV Care Continuum among Female Sex Workers: A Key Population in Lilongwe, Malawi

OBJECTIVE

The HIV care continuum among female sex workers (FSW), a key population, has not been well characterized, especially within the generalized epidemics of sub-Saharan Africa. This was the first study to characterize the HIV care continuum among FSW in Lilongwe, Malawi.

METHODS

From July through September 2014, we used venue-based sampling to enroll 200 adult FSW in Lilongwe, Malawi into a cross-sectional evaluation assessing HIV care continuum outcomes. Seropositive FSW, identified using HIV rapid testing, received rapid CD4 counts in addition to viral loads using dried blood spots. We calculated proportions of HIV-infected FSW who had history of care, were on ART, and had suppressed viral load and we used Poisson regression to estimate the associations of demographic characteristics and transmission risk behaviors with each outcome.

RESULTS

HIV seroprevalence was 69% (n = 138). Among all FSW the median age was 24 years (IQR: 22-28). Among the 20% who were newly diagnosed and reported previously testing negative, the median time since last HIV test was 11 months (interquartile range: 3-17). The majority (69%) of HIV-infected FSW had a history of HIV care, 52% reported current ART use, and 45% were virally suppressed. Of the FSW who reported current ART use, 86% were virally suppressed. Transmission risk behaviors were not associated with continuum outcomes.

CONCLUSIONS

FSW in Lilongwe were predominately young and have a high HIV prevalence. Only half of HIV-infected FSW reported current ART use, but the majority of those on ART were virally suppressed. To reduce ongoing transmission and improve health outcomes, increased HIV testing, care engagement, and ART coverage is urgently needed among FSW. Universal testing and treatment strategies for all FSW in Malawi must be strongly considered.

Hepatitis C virus treatment as prevention in people who inject drugs: testing the evidence

PURPOSE OF REVIEW

The majority of hepatitis C virus (HCV) infections in the United Kingdom and many developing countries were acquired through injecting. New clinical guidance suggests that HCV treatment should be offered to people with a transmission risk - such as people who inject drugs (PWID) - irrespective of severity of liver disease. We consider the strength of the evidence base and potential problems in evaluating HCV treatment as prevention among PWID.

RECENT FINDINGS

There is good theoretical evidence from dynamic models that HCV treatment for PWID could reduce HCV chronic prevalence and incidence among PWID. Economic evaluations from high-income settings have suggested HCV treatment for PWID is cost-effective, and that in many settings HCV treatment of PWID could be more cost-effective than treating those at an equivalent stage with no ongoing transmission risk. Epidemiological studies of older interferon treatments have suggested that PWID can achieve similar treatment outcomes to other patient groups treated for chronic HCV. Impact and cost-effectiveness of HCV treatment is driven by the potential 'prevention benefit' of treating PWID. Model projections suggest that more future infections, end stage liver disease, and HCV-related deaths will be averted than lost through reinfection of PWID treated successfully for HCV. However, there is to date no empirical evidence from trials or observational studies that test the model projections and 'prevention benefit' hypothesis. In part this is because of uncertainty in the evidence base but also there is unlikely to have been a change in HCV prevalence due to HCV treatment because PWID HCV treatment rates historically in most sites have been low, and any scale-up and switch to the new direct acting antiviral has not yet occurred. There are a number of key uncertainties in the data available on PWID that need to be improved and addressed to evaluate treatment as prevention. These include estimates of the prevalence of PWID, measurements of HCV chronic prevalence and incidence among PWID, and how to interpret reinfection rates as potential outcome measures.

SUMMARY

Eliminating HCV through scaling up treatment is a theoretical possibility. But empirical data are required to demonstrate that HCV treatment can reduce HCV transmission, which will require an improved evidence base and analytic framework for measuring PWID and HCV prevalence.

Disability and Living with HIV: Baseline from a Cohort of People on Long Term ART in South Africa

BACKGROUND

Through access to life saving antiretroviral treatment (ART) in southern Africa, HIV has been reconceptualised as a chronic disease. This comes with new challenges of HIV-related co-morbidities and disabilities. We still lack an understanding of the types and scope of disabilities experienced by people on long term ART and how this impacts health, adherence, and livelihood. This paper describes the results of a cohort study examining the new health- and disability-related needs of the millions of people on ART in the region.

METHODS

Data was collected from a cohort of people who had been on ART for six months or longer in a semi-urban public health care setting in South Africa. 1042 adults (18 and older) participated in the cross-sectional study which investigated disabilities/activity limitations, health, ART adherence, depression symptoms, and livelihood. We analysed the associations between these constructs using descriptive statistics, and bivariate and multivariate analyses.

RESULTS

A large number of participants (35.5%) obtained a weighted score of two or more on the WHODAS 2.0 indicating possible activity limitations. A positive relationship was found between activity limitations and depression symptoms, adherence, and worse health outcomes, while none was found for BMI or CD4 count. These associations varied by type of activity limitations and, in some cases, by gender.

CONCLUSION

Activity limitations are potentially experienced by a large portion of people on ART in southern Africa which impacts health and ART adherence negatively. These results highlight the importance of better understanding the new health-related needs of people who are on long term ART, as well as the nuances of the disability they experience. This is urgently needed in order to enable HIV-endemic countries to better prepare for the new health-related needs of the millions of people on ART in southern Africa.

Partner notification in the context of HIV: an interest-analysis

Codes of confidentiality play an essential role in the intimate discourses in many learned professions. Codes with various prescriptions exist. The Hippocratic Oath for example, prescribes rewards to the secret keeper, for keeping secret what ought to be kept secret, and punishments for failing. In public health practice, partner notification, arguably is one endeavor that tests the durability of this secret keeping doctrine of the health professional. We present an interest-analysis of partner notification in the context of HIV service rendition. Using principles-based analysis, the interests of the individual, the state/public health, and the bioethicist's are discussed. The public health interests in partner notification, which are usually backed by state statutes and evidence, are premised on the theory that partners are entitled to knowledge. This theory posits that knowledge empowers individuals to avoid continuing risks; knowledge of infection allows for early treatment; and that knowledgeable partners can adapt their behavior to prevent further transmission of infection to others. However, persons infected with HIV often have counter interests. For instance, an infected person may desire to maintain the privacy of their health status from unnecessary disclosure because of the negative impacts of disclosure, or because notification without a matching access to HIV prevention and treatment services is detrimental. The interest of the bioethicist in this matter is to facilitate a resolution of these conflicted interests. Our analysis concludes that governmental interests are not absolute in comparison with the interests of the individual. We reiterate that any effort to morally balance the benefits of partner notification with its burdens ought to first recognize the multivalent nature of the interests at play.

Potential impact of existing interventions and of antiretroviral use in female sex workers on transmission of HIV in Burkina Faso: a modeling study

BACKGROUND

The impact and cost-effectiveness of antiretroviral treatment (ART) as prevention is likely to vary depending on the local context. Burkina Faso has a concentrated mature HIV epidemic where female sex workers (FSW) are thought to have driven HIV transmission.

METHODS

A dynamic HIV transmission model was developed using data from the Yerelon FSW cohort in Bobo-Dioulasso and population surveys. Compared with current ART provision [status quo (SQ)], the model estimated the proportion of HIV infections averted or incremental life-years gained per additional person-year of ART over 20 years for ART targeting different subgroups or expanding eligibility to all HIV-infected individuals compared with SQ.

RESULTS

Modeling suggests that condom use within commercial sex has averted 40% of past HIV infections. Continuing SQ averts 35%-47% of new infections over 20 years compared with no ART. Expanding ART eligibility to all HIV-infected individuals and increasing recruitment (80% per year) could avert a further 65% of new infections, whereas targeting full-time FSW or all FSWs achieved less impact but was more efficient in terms of life-years gained per 100 person-years of ART. Local HIV elimination is possible with expanded ART provision to FSWs but requires condom use within commercial sex to be maintained at high levels.

CONCLUSIONS

Increasing FSW recruitment onto ART could be a highly efficient method for reducing HIV transmission in concentrated epidemic settings but should not be undertaken at the expense of existing interventions for FSWs. Specialized clinics providing multiple interventions for FSWs should be a fundamental component of prevention in concentrated epidemics.

Retention and risk factors for loss to follow-up of female and male sex workers on antiretroviral treatment in Ivory Coast: a retrospective cohort analysis

BACKGROUND

Antiretroviral therapy (ART) for HIV-infected sex workers is an important HIV prevention strategy. However, sex workers may have additional challenges for retention in ART care. The objectives of this study were to assess retention of sex workers on ART in a routine setting in Ivory Coast and identify risk factors for loss to follow-up (LTFU).

METHODS

The design was a retrospective cohort study. An analysis of clinic files was conducted in 2 sites providing ART services to sex workers in Ivory Coast. Demographic, behavior, and clinical data of female and male sex workers on ART were abstracted onto a standardized anonymous data collection form. Data collection took place between May 11 and 28, 2010.

RESULTS

A total of 376 female and 38 male sex workers were included in the analysis. The retention probability was 75% at 6 months, 68% at 12 months, 55% at 24 months, and 47% at 36 months. Attrition was mainly because of LTFU. Factors significantly associated with LTFU in bivariate analysis were lower schooling level, later calendar year of starting ART, and not receiving initial adherence counseling. Later year of starting ART and not receiving adherence counseling at ART initiation remained significantly associated with LTFU in a multivariate Cox regression model.

CONCLUSIONS

To improve the retention of sex workers on ART, there is a need for more in-depth investigation of the role of pre-ART counseling and the increasing rates of LTFU with each calendar year.

Scaling up of HIV treatment for men who have sex with men in Bangkok: a modelling and costing study

BACKGROUND

Despite the high prevalence of HIV in men who have sex with men (MSM) in Bangkok, little investment in HIV prevention for MSM has been made. HIV testing and treatment coverage remains low. Through a pragmatic programme-planning approach, we assess possible service linkage and provision of HIV testing and antiretroviral treatment (ART) to MSM in Bangkok, and the most cost-effective scale-up strategy.

METHODS

We obtained epidemiological and service capacity data from the Thai National Health Security Office database for 2011. We surveyed 13 representative medical facilities for detailed operational costs of HIV-related services for sexually active MSM (defined as having sex with men in the past 12 months) in metropolitan Bangkok. We estimated the costs of various ART scale-up scenarios, accounting for geographical accessibility across Bangkok. We used an HIV transmission population-based model to assess the cost-effectiveness of the scenarios.

FINDINGS

For present HIV testing (23% [95% CI 17-36] of MSM at high risk in 2011) and ART provision (20% of treatment-eligible MSM at high risk on ART in 2011) to be sustained, a US$73·8 million ($51·0 million to $97·0 million) investment during the next decade would be needed, which would link an extra 43,000 (27,900-58,000) MSM at high risk to HIV testing and 5100 (3500-6700) to ART, achieving an ART coverage of 44% for MSM at high risk in 2022. An additional $55·3 million investment would link an extra 46,700 (30,300-63,200) MSM to HIV testing and 12,600 (8800-16,600) to ART, achieving universal ART coverage of this population by 2022. This increased investment is achievable within present infrastructure capacity. Consequently, an estimated 5100 (3600-6700) HIV-related deaths and 3700 (2600-4900) new infections could be averted in MSM by 2022, corresponding to a 53% reduction in deaths and a 35% reduction in infections from 2012 levels. The expansion would cost an estimated $10,809 (9071-13,274) for each HIV-related death, $14,783 (12,389-17,960) per new infection averted, and $351 (290-424) per disability-adjusted life-year averted.

INTERPRETATION

Spare capacity in Bangkok's medical facilities can be used to expand ART access for MSM with large epidemiological benefits. The expansion needs increased funding directed to MSM services, but given the epidemiological trends, is probably cost effective. Our modelling approach and outcomes are likely to be applicable to other settings.

FUNDING

World Bank Group and Australian National Health and Medical Research Council.

Influence of the timing of antiretroviral therapy on the potential for normalization of immune status in human immunodeficiency virus 1-infected individuals

IMPORTANCE

In individuals with human immunodeficiency virus 1 (HIV-1) infection who are receiving antiretroviral therapy (ART), factors that promote full immune recovery are not well characterized.

OBJECTIVE

To investigate the influence of the timing of ART relative to HIV-1 infection on normalization of CD4+ T-cell counts, AIDS risk, and immune function.

DESIGN, SETTING, AND PARTICIPANTS

Participants in the observational US Military HIV Natural History Study with documented estimated dates of seroconversion (EDS) who achieved virologic suppression with ART were evaluated. Markers indicative of immune activation, dysfunction, and responsiveness were determined. Responses to hepatitis B virus (HBV) vaccine, an indicator of in vivo immune function, were also assessed. The timing of ART was indexed to the EDS and/or entry into the cohort. The CD4+ counts in HIV-1-uninfected populations were surveyed.

MAIN OUTCOMES AND MEASURES

Normalization of CD4+ counts to 900 cells/μL or higher, AIDS development, HBV vaccine response, as well as T-cell activation, dysfunction, and responsiveness.

RESULTS

The median CD4+ count in HIV-1-uninfected populations was approximately 900 cells/μL. Among 1119 HIV-1-infected participants, CD4+ normalization was achieved in 38.4% vs 28.3% of those initiating ART within 12 months vs after 12 months from the EDS (P = .001). Incrementally higher CD4+ recovery (<500, 500-899, and ≥900 cells/μL) was associated with stepwise decreases in AIDS risk and reversion of markers of immune activation, dysfunction, and responsiveness to levels approximating those found in HIV-1-uninfected persons. Participants with CD4+ counts of 500 cells/μL or higher at study entry (adjusted odds ratio [aOR], 2.00; 95% CI, 1.51-2.64; P < .001) or ART initiation (aOR, 4.08; 95% CI, 3.14-5.30; P < .001) had significantly increased CD4+ normalization rates compared with other participants. However, even among individuals with a CD4+ count of 500 cells/μL or higher at both study entry and before ART, the odds of CD4+ normalization were 80% lower in those initiating ART after 12 months from the EDS and study entry (aOR, 0.20; 95% CI, 0.07-0.53; P = 001). Initiation of ART within 12 months of EDS vs later was associated with a significantly lower risk of AIDS (7.8% vs 15.3%; P = .002), reduced T-cell activation (percent CD4+HLA-DR+ effector memory T cells, 12.0% vs 15.6%; P = .03), and increased responsiveness to HBV vaccine (67.9% vs 50.9%; P = .07).

CONCLUSIONS AND RELEVANCE

Deferral of ART beyond 12 months of the EDS diminishes the likelihood of restoring immunologic health in HIV-1-infected individuals.

Reduced darunavir dose is as effective in maintaining HIV suppression as the standard dose in virologically suppressed HIV-infected patients: a randomized clinical trial

OBJECTIVES

Maximizing ART efficiency is of growing interest. This study assessed the efficacy, safety, pharmacokinetics and economics of a darunavir dose-reduction strategy.

METHODS

This was a multicentre, randomized, open-label clinical trial in HIV-infected patients with plasma HIV-1 RNA <50 copies/mL while receiving triple ART including 800 mg of darunavir once daily. Participants were randomized to continue 800 mg of darunavir (DRV800) or to 600 mg of darunavir (DRV600), both once daily. Treatment failure was defined as two consecutive HIV-1 RNA determinations >50 copies/mL or discontinuation of study treatment by week 48. The study was registered at https://www.clinicaltrialsregister.eu (trial number 2011-006272-39).

RESULTS

Fifty participants were allocated to each arm. The mean (SD) CD4+ T cell count at baseline was 562 (303) cells/mm(3) and HIV-1 RNA had been <50 copies/mL for a median (IQR) of 106.9 (43.4-227.9) weeks before enrolment. At week 48 no treatment failure had occurred in 45/50 (90%) DRV600 patients and in 47/50 (94%) DRV800 patients (difference -4%; 95% CI lower limit, -12.9%). When only patients with virological data were considered, that endpoint was met by 45/48 (94%) in the DRV600 arm and 47/49 (96%) in the DRV800 arm (difference -2.2%; 95% CI lower limit, -9.6%). Darunavir exposure was similar in the two arms. The average reduction in annual cost per successfully treated DRV600-arm patient was US$7273.

CONCLUSIONS

The efficacy of a darunavir daily dose of 600 mg seemed to be similar to the efficacy of the standard 800 mg dose in virologically suppressed HIV-infected patients on triple ART. This strategy can potentially translate to substantial savings in the cost of care of HIV-infected patients.

HIV treatment as prevention: contradictory perspectives from dynamic mathematical models

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

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

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

Individualized diagnosis interventions can add significant effectiveness in reducing human immunodeficiency virus incidence among men who have sex with men: insights from Southern California

PURPOSE

In this article, we examine the effectiveness of a variety of HIV diagnosis interventions in recently HIV-diagnosed men who have sex with men (MSM). These interventions use the preventive potential of postdiagnosis behavior change (PDBC), as measured by the reduction in the number of new infections. Empirical evidence for PDBC was presented in the behavioral substudy of the Southern California Acute Infection and Early Disease Research Program. In previous modeling work, we demonstrated the existing preventive effects of PDBC. However, a large proportion of new infections among MSM are either undiagnosed or diagnosed late, and the preventive potential of PDBC is not fully utilized.

METHODS

We derive empirical, stochastic, network-based models to examine the effectiveness of several diagnosis interventions that account for PDBC among MSM over a 10-year period. These interventions involve tests with shorter detection windows, more frequent testing, and individualized testing regimens.

RESULTS

We find that individualized testing interventions (i.e., testing individuals every three partners or 3 months, whichever is first, or every six partners or 6 months, whichever is first) result in significantly fewer new HIV infections than the generalized interventions we consider.

CONCLUSIONS

This work highlights the potential of individualized interventions for new public health policies in HIV prevention.

Antiretroviral therapy uptake, attrition, adherence and outcomes among HIV-infected female sex workers: a systematic review and meta-analysis

Purpose

We aimed to characterize the antiretroviral therapy (ART) cascade among female sex workers (FSWs) globally.

Methods

We systematically searched PubMed, Embase and MEDLINE in March 2014 to identify studies reporting on ART uptake, attrition, adherence, and outcomes (viral suppression or CD4 count improvements) among HIV-infected FSWs globally. When possible, available estimates were pooled using random effects meta-analyses (with heterogeneity assessed using Cochran's Q test and I² statistic).

Results

39 studies, reporting on 21 different FSW study populations in Asia, Africa, North America, South America, and Central America and the Caribbean, were included. Current ART use among HIV-infected FSWs was 38% (95% CI: 29%–48%, I² = 96%, 15 studies), and estimates were similar between high-, and low- and middle-income countries. Ever ART use among HIV-infected FSWs was greater in high-income countries (80%; 95% CI: 48%–94%, I² = 70%, 2 studies) compared to low- and middle-income countries (36%; 95% CI: 7%–81%, I² = 99%, 3 studies). Loss to follow-up after ART initiation was 6% (95% CI: 3%–11%, I² = 0%, 3 studies) and death after ART initiation was 6% (95% CI: 3%–11%, I² = 0%, 3 studies). The fraction adherent to ≥95% of prescribed pills was 76% (95% CI: 68%–83%, I² = 36%, 4 studies), and 57% (95% CI: 46%–68%, I² = 82%, 4 studies) of FSWs on ART were virally suppressed. Median gains in CD4 count after 6 to 36 months on ART, ranged between 103 and 241 cells/mm³ (4 studies).

Conclusions

Despite global increases in ART coverage, there is a concerning lack of published data on HIV treatment for FSWs. Available data suggest that FSWs can achieve levels of ART uptake, retention, adherence, and treatment response comparable to that seen among women in the general population, but these data are from only a few research settings. More routine programme data on HIV treatment among FSWs across settings should be collected and disseminated.

ARV-based HIV prevention for women - where we are in 2014

Women continue to be at special risk for HIV acquisition due to a complex mix of biological, behavioural, structural, cultural and social factors, with unacceptable rates of new infection. Scientific advances over the past decade have highlighted the use of antiretroviral (ARV) drugs as pre-exposure prophylaxis (PrEP) to prevent HIV acquisition (sexually, parenterally and vertically) and ARV treatment (ART) for HIV-positive patients to prevent onward transmission (treatment as prevention – TasP). This paper reviews the evidence base for PrEP and TasP, describes new products in development and the need to translate research findings into programmes with impact at the population level.

The HIV care cascade and antiretroviral therapy in female sex workers: implications for HIV prevention

To achieve viral suppression and fully benefit from antiretroviral therapy (ART), it is important that individuals with HIV know that they are HIV infected, link to and remain in HIV care, start and remain on ART and adhere to treatment. In HIV epidemics where female sex workers (FSWs) are key drivers of HIV transmission, the extent to which FSWs use ART and engage in the HIV care cascade could have a considerable impact on HIV transmission from FSWs to the wider population. In this article we review the spectrum of FSW engagement in the HIV care cascade, look at the impact of the HIV care cascade and ART use among FSWs on population-level HIV transmission and discuss HIV prevention for FSWs in the context of ART and the HIV care cascade.

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.

Levels of alcohol use and history of HIV testing among female sex workers in Mombasa, Kenya

HIV testing is a critical first step to accessing HIV care and treatment, particularly for high-risk groups such as female sex workers (FSWs). Alcohol use may be a barrier to accessing HIV services, including HIV testing. We analyzed data from a cross-sectional survey of 818 FSWs in Mombasa, Kenya, and estimated the association between different levels of alcohol use and having never tested for HIV. In multivariable analyses, higher levels of alcohol consumption were associated with having never tested for HIV (PR 1.60; 95% CI: 1.07, 2.40). Future interventions should explore whether reducing harmful drinking improves HIV testing among FSWs.

The costs and benefits of Option B+ for the prevention of mother-to-child transmission of HIV

OBJECTIVE

Most countries follow WHO 2010 guidelines for the prevention of mother-to-child transmission (PMTCT) of HIV using either Option A or B for women not yet eligible for antiretroviral therapy (ART). Both of these approaches involve the use of antiretrovirals during pregnancy and breastfeeding. Some countries have adopted a new strategy, Option B+, in which HIV-positive pregnant women are started immediately on ART and continued for life. Option B+ is more costly than Options A or B, but provides additional health benefits. In this article, we estimate the additional costs and effectiveness of Option B+.

METHODS

We developed a deterministic model to simulate births, breastfeeding, and HIV infection in women in four countries, Kenya, Zambia, South Africa, and Vietnam that differ in fertility rate, birth interval, age at first birth, and breastfeeding patterns, but have similar age at HIV infection. We estimated the total PMTCT costs and new child infections under Options A, B, and B+, and measured cost-effectiveness as the incremental PMTCT-related costs per child infection averted. We included adult sexual transmissions averted from ART, the corresponding costs saved, and estimated the total incremental cost per transmission (child and adult) averted.

RESULTS

When considering PMTCT-related costs and child infections, Option B+ was the most cost-effective strategy costing between $6000 and $23 000 per infection averted compared with Option A. Option B+ averted more child infections compared with Option B in all four countries and cost less than Option B in Kenya and Zambia. When including adult sexual transmissions averted, Option B+ cost less and averted more infections than Options A and B.

Exploring the population-level impact of antiretroviral treatment: the influence of baseline intervention context

OBJECTIVE

To compare the potential population-level impact of expanding antiretroviral treatment (ART) in HIV epidemics concentrated among female sex workers (FSWs) and clients, with and without existing condom-based FSW interventions.

DESIGN

Mathematical model of heterosexual HIV transmission in south India.

METHODS

We simulated HIV epidemics in three districts to assess the 10-year impact of existing ART programs (ART eligibility at CD4 cell count ≤350) beyond that achieved with high condom use, and the incremental benefit of expanding ART by either increasing ART eligibility, improving access to care, or prioritizing ART expansion to FSWs/clients. Impact was estimated in the total population (including FSWs and clients).

RESULTS

In the presence of existing condom-based interventions, existing ART programs (medium-to-good coverage) were predicted to avert 11-28% of remaining HIV infections between 2014 and 2024. Increasing eligibility to all risk groups prevented an incremental 1-15% over existing ART programs, compared with 29-53% when maximizing access to all risk groups. If there was no condom-based intervention, and only poor ART coverage, then expanding ART prevented a larger absolute number but a smaller relative fraction of HIV infections for every additional person-year of ART. Across districts and baseline interventions, for every additional person-year of treatment, prioritizing access to FSWs was most efficient (and resource saving), followed by prioritizing access to FSWs and clients.

CONCLUSION

The relative and absolute benefit of ART expansion depends on baseline condom use, ART coverage, and epidemic size. In south India, maximizing FSWs' access to care, followed by maximizing clients' access are the most efficient ways to expand ART for HIV prevention, across baseline intervention context.

Balancing efficiency, equity and feasibility of HIV treatment in South Africa - development of programmatic guidance

South Africa, the country with the largest HIV epidemic worldwide, has been scaling up treatment since 2003 and is rapidly expanding its eligibility criteria. The HIV treatment programme has achieved significant results, and had 1.8 million people on treatment per 2011. Despite these achievements, it is now facing major concerns regarding (i) efficiency: alternative treatment policies may save more lives for the same budget; (ii) equity: there are large inequalities in who receives treatment; (iii) feasibility: still only 52% of the eligible population receives treatment.Hence, decisions on the design of the present HIV treatment programme in South Africa can be considered suboptimal. We argue there are two fundamental reasons to this. First, while there is a rapidly growing evidence-base to guide priority setting decisions on HIV treatment, its included studies typically consider only one criterion at a time and thus fail to capture the broad range of values that stakeholders have. Second, priority setting on HIV treatment is a highly political process but it seems no adequate participatory processes are in place to incorporate stakeholders' views and evidences of all sorts.We propose an alternative approach that provides a better evidence base and outlines a fair policy process to improve priority setting in HIV treatment. The approach integrates two increasingly important frameworks on health care priority setting: accountability for reasonableness (A4R) to foster procedural fairness, and multi-criteria decision analysis (MCDA) to construct an evidence-base on the feasibility, efficiency, and equity of programme options including trade-offs. The approach provides programmatic guidance on the choice of treatment strategies at various decisions levels based on a sound conceptual framework, and holds large potential to improve HIV priority setting in South Africa.

Effect of early antiretroviral therapy on sexual behaviors and HIV-1 transmission risk among adults with diverse heterosexual partnership statuses in Côte d'Ivoire

Background. The effect of early initiation of antiretroviral therapy (ART; ie, at CD4⁺ T-cell counts >350 cells/mm³) on sexual behaviors and human immunodeficiency virus type 1 (HIV) transmission risk has not been documented in populations other than HIV-serodiscordant couples in stable relationships.

Methods. On the basis of data from a behavioral study nested in a randomized, controlled trial (Temprano-ANRS12136) of early ART, we compared proportions of risky sex (ie, unprotected sex with a partner of negative/unknown HIV status) reported 12 months after inclusion between participants randomly assigned to initiate ART immediately (hereafter, “early ART”) or according to ongoing World Health Organization criteria. Group-specific HIV transmission rates were estimated on the basis of sexual behaviors and viral load–specific per-act HIV transmission probabilities. The ratio of transmission rates was computed to estimate the protective effect of early ART.

Results. Among 957 participants (baseline median CD4⁺ T-cell count, 478 cells/mm³), 46.0% reported sexual activity in the past month; of these 46.0%, sexual activity for 41.5% involved noncohabiting partners. The proportion of subjects who engaged in risky sex was 10.0% in the early ART group, compared with 12.8% in the standard ART group (P = .17). After accounting for sexual behaviors and viral load, we estimated that the protective effect of early ART was 90% (95% confidence interval, 81%–95%).

Conclusion. Twelve months after inclusion, patients in the early and standard ART groups reported similar sexual behaviors. Early ART decreased the estimated risk of HIV transmission by 90%, suggesting a major prevention benefit among seronegative sex partners in stable or casual relationships with seropositive individuals.

"You are wasting our drugs": health service barriers to HIV treatment for sex workers in Zimbabwe

Background

Although disproportionately affected by HIV, sex workers (SWs) remain neglected by efforts to expand access to antiretroviral treatment (ART). In Zimbabwe, despite the existence of well-attended services targeted to female SWs, fewer than half of women diagnosed with HIV took up referrals for assessment and ART initiation; just 14% attended more than one appointment. We conducted a qualitative study to explore the reasons for non-attendance and the high rate of attrition.

Methods

Three focus group discussions (FGD) were conducted in Harare with HIV-positive SWs referred from the ‘Sisters with a Voice’ programme to a public HIV clinic for ART eligibility screening and enrolment. Focus groups explored SWs’ experiences and perceptions of seeking care, with a focus on how managing HIV interacted with challenges specific to being a sex worker. FGD transcripts were analyzed by identifying emerging and recurring themes that were specifically related to interactions with health services and how these affected decision-making around HIV treatment uptake and retention in care.

Results

SWs emphasised supply-side barriers, such as being demeaned and humiliated by health workers, reflecting broader social stigma surrounding their work. Sex workers were particularly sensitive to being identified and belittled within the health care environment. Demand-side barriers also featured, including competing time commitments and costs of transport and some treatment, reflecting SWs’ marginalised socio-economic position.

Conclusion

Improving treatment access for SWs is critical for their own health, programme equity, and public health benefit. Programmes working to reduce SW attrition from HIV care need to proactively address the quality and environment of public services. Sensitising health workers through specialised training, refining referral systems from sex-worker friendly clinics into the national system, and providing opportunities for SW to collectively organise for improved treatment and rights might help alleviate the barriers to treatment initiation and attention currently faced by SW.

Future of phylogeny in HIV prevention

The success of the HIV Prevention Trials Network 052 trial has led to revisions in HIV-1 treatment guidelines. Antiretroviral therapy may reduce the risk of HIV-1 transmissions at the population level. The design of successful treatment as prevention interventions will be predicated on a comprehensive understanding of the spatial, temporal, and biological dynamics of heterosexual men who have sex with men and intravenous drug user epidemics. Viral phylogenetics can capture the underlying structure of transmission networks based on the genetic interrelatedness of viral sequences and cluster networks that could not be otherwise identified. This article describes the phylogenetic expansion of the Montreal men who have sex with men epidemic over the last decade. High rates of coclustering of primary infections are associated with 1 infection leading to 13 onward transmissions. Phylogeny substantiates the role of primary and recent stage infection in transmission dynamics, underlying the importance of timely diagnosis and immediate antiretroviral therapy initiation to avert transmission cascades.

Combination prevention: new hope for stopping the epidemic

HIV research has identified approaches that can be combined to be more effective in transmission reduction than any 1 modality alone: delayed adolescent sexual debut, mutual monogamy or sexual partner reduction, correct and consistent condom use, pre-exposure prophylaxis with oral antiretroviral drugs or vaginal microbicides, voluntary medical male circumcision, antiretroviral therapy (ART) for prevention (including prevention of mother to child HIV transmission [PMTCT]), treatment of sexually transmitted infections, use of clean needles for all injections, blood screening prior to donation, a future HIV prime/boost vaccine, and the female condom. The extent to which evidence-based modalities can be combined to prevent substantial HIV transmission is largely unknown, but combination approaches that are truly implementable in field conditions are likely to be far more effective than single interventions alone. Analogous to PMTCT, "treatment as prevention" for adult-to-adult transmission reduction includes expanded HIV testing, linkage to care, antiretroviral coverage, retention in care, adherence to therapy, and management of key co-morbidities such as depression and substance use. With successful viral suppression, persons with HIV are far less infectious to others, as we see in the fields of sexually transmitted infection control and mycobacterial disease control (tuberculosis and leprosy). Combination approaches are complex, may involve high program costs, and require substantial global commitments. We present a rationale for such investments and cite an ongoing research agenda that seeks to determine how feasible and cost-effective a combination prevention approach would be in a variety of epidemic contexts, notably that in a sub-Saharan Africa.

Can we stop AIDS with antiretroviral-based treatment as prevention?

Challenges to scaling up treatment as prevention (TasP) of HIV transmission are considerable in the developing-world context and include accessing at-risk populations, human resource shortages, adherence and retention in care, access to newer treatments, measurement of treatment effects, and long-term sustainable funding. Optimism about ending AIDS needs to be tempered by the realities of the logistic challenges of strengthening health systems in countries most affected and by balancing TasP with overall combination prevention approaches.

HIV treatment as prevention: modelling the cost of antiretroviral treatment--state of the art and future directions

Policy discussions about the feasibility of massively scaling up antiretroviral therapy (ART) to reduce HIV transmission and incidence hinge on accurately projecting the cost of such scale-up in comparison to the benefits from reduced HIV incidence and mortality. We review the available literature on modelled estimates of the cost of providing ART to different populations around the world, and suggest alternative methods of characterising cost when modelling several decades into the future. In past economic analyses of ART provision, costs were often assumed to vary by disease stage and treatment regimen, but for treatment as prevention, in particular, most analyses assume a uniform cost per patient. This approach disregards variables that can affect unit cost, such as differences in factor prices (i.e., the prices of supplies and services) and the scale and scope of operations (i.e., the sizes and types of facilities providing ART). We discuss several of these variables, and then present a worked example of a flexible cost function used to determine the effect of scale on the cost of a proposed scale-up of treatment as prevention in South Africa. Adjusting previously estimated costs of universal testing and treatment in South Africa for diseconomies of small scale, i.e., more patients being treated in smaller facilities, adds 42% to the expected future cost of the intervention.

HIV treatment as prevention: principles of good HIV epidemiology modelling for public health decision-making in all modes of prevention and evaluation

Public health responses to HIV epidemics have long relied on epidemiological modelling analyses to help prospectively project and retrospectively estimate the impact, cost-effectiveness, affordability, and investment returns of interventions, and to help plan the design of evaluations. But translating model output into policy decisions and implementation on the ground is challenged by the differences in background and expectations of modellers and decision-makers. As part of the PLoS Medicine Collection "Investigating the Impact of Treatment on New HIV Infections"--which focuses on the contribution of modelling to current issues in HIV prevention--we present here principles of "best practice" for the construction, reporting, and interpretation of HIV epidemiological models for public health decision-making on all aspects of HIV. Aimed at both those who conduct modelling research and those who use modelling results, we hope that the principles described here will become a shared resource that facilitates constructive discussions about the policy implications that emerge from HIV epidemiology modelling results, and that promotes joint understanding between modellers and decision-makers about when modelling is useful as a tool in quantifying HIV epidemiological outcomes and improving prevention programming.

HIV treatment as prevention: models, data, and questions--towards evidence-based decision-making

Antiretroviral therapy (ART) for those infected with HIV can prevent onward transmission of infection, but biological efficacy alone is not enough to guide policy decisions about the role of ART in reducing HIV incidence. Epidemiology, economics, demography, statistics, biology, and mathematical modelling will be central in framing key decisions in the optimal use of ART. PLoS Medicine, with the HIV Modelling Consortium, has commissioned a set of articles that examine different aspects of HIV treatment as prevention with a forward-looking research agenda. Interlocking themes across these articles are discussed in this introduction. We hope that this article, and others in the collection, will provide a foundation upon which greater collaborations between disciplines will be formed, and will afford deeper insights into the key factors involved, to help strengthen the support for evidence-based decision-making in HIV prevention.