David Hoos

Antiretroviral Therapy in Prevention of HIV and TB: Update on Current Research Efforts

There is considerable scientific evidence supporting the use of antiretroviral therapy (ART) in prevention of human immunodeficiency virus (HIV) and tuberculosis (TB) infections. The complex nature of the HIV and TB prevention responses, resource constraints, remaining questions about cost and feasibility, and the need to use a solid evidence base to make policy decisions, and the implementation challenges to translating trial data to operational settings require a well-organised and coordinated response to research in this area. To this end, we aimed to catalogue the ongoing and planned research activities that evaluate the impact of ART plus other interventions on HIV- and/or TB-related morbidity, mortality, risk behaviour, HIV incidence and transmission. Using a limited search methodology, 50 projects were identified examining ART as prevention, representing 5 regions and 52 countries with a global distribution. There are 24 randomised controlled clinical trials with at least 12 large randomised individual or community cluster trials in resource-constrained settings that are in the planning or early implementation stages. There is considerable heterogeneity between studies in terms of methodology, interventions and geographical location. While the identified studies will undoubtedly advance our understanding of the efficacy and effectiveness of ART for prevention, some key questions may remain unanswered or only partially answered. The large number and wide variety of research projects emphasise the importance of this research issue and clearly demonstrate the potential for synergies, partnerships and coordination across funding agencies.

Program-level and contextual-level determinants of low-median CD4+ cell count in cohorts of persons initiating ART in eight sub-Saharan African countries.

Objective:In sub-Saharan Africa, many patients initiate antiretroviral therapy (ART) at CD4+ cell counts much lower than those recommended in national guidelines. We examined program-level and contextual-level factors associated with low median CD4+ cell count at ART initiation in populations initiating ART. Design:Multilevel analysis of aggregate and program-level service delivery data. Methods:We examined data on 1690 cohorts of patients initiating ART during 2004–2008 in eight sub-Saharan African countries. Cohorts with median CD4+ less than 111 cells/&mgr;l (the lowest quartile) were classified as having low median CD4+ cell count at ART initiation. Cohort information was combined with time-updated program-level data and subnational contextual-level data, and analyzed using multilevel models. Results:The 1690 cohorts had median CD4+ cell count of 136 cells/&mgr;l and included 121 504 patients initiating ART at 267 clinics. Program-level factors associated with low cohort median CD4+ cell count included urban setting [adjusted odds ratio (AOR) 2.1; 95% confidence interval (CI) 1.3–3.3], lower provider-to-patient ratio (AOR 2.2; 95% CI 1.3–4.0), no PMTCT program (AOR 3.6; 95% CI 1.0–12.8), outreach services for ART patients only vs. both pre-ART and ART patients (AOR 2.4; 95% CI 1.5–3.9), fewer vs. more adherence support services (AOR 1.6; 95% CI 1.0–2.5), and smaller cohort size (AOR 2.5; 95% CI 1.4–4.5). Contextual-level factors associated with low cohort median CD4+ cell count included initiating ART in areas where a lower proportion of the population heard of AIDS, tested for HIV recently, and a higher proportion believed ‘limiting themselves to one HIV-uninfected sexual partner reduces HIV risk’. Conclusion:Determinants of CD4+ cell count at ART initiation in populations initiating ART operate at multiple levels. Structural interventions targeting points upstream from ART initiation along the continuum from infection to diagnosis to care engagement are needed.

Factors Associated with Late Antiretroviral Therapy Initiation among Adults in Mozambique

Background Despite recent changes to expand the ART eligibility criteria in sub-Saharan Africa, many patients still initiate ART in the advanced stages of HIV infection, which contributes to increased early mortality rates, poor patient outcomes, and onward transmission. Methods To evaluate individual and clinic-level factors associated with late ART initiation in Mozambique, we conducted a retrospective sex-specific analysis of data from 36,411 adult patients who started ART between January 2005 and June 2009 at 25 HIV clinics in Mozambique. Late ART initiation was defined as CD4 count<100 cells/µL or WHO stage IV. Mixed effects models were used to identify patient- and clinic-level factors associated with late ART initiation. Results The proportion of patients initiating ART late decreased from 46% to 37% during 2005–2007, but remained constant (between 37–33%) from 2007–2009. Of those who initiated ART late (median CD4 = 57 cells/µL), 5% were known to have died and 54% were lost to clinic within 6 months of ART initiation (compared with 2% and 47% among other patients starting ART [median CD4 = 192 cells/µL]). In multivariate analysis, female sex and pregnancy at ART initiation (AORfemale_not_pregnant_vs._male = 0.66, 95%CI [0.62–0.69]; AORpregnant_vs._non_pregnant = 0.60, 95%CI [0.49–0.73]), younger and older age (AOR15–25_vs.26–30 = 0.86, 95%CI [0.79–0.94], AOR>45_vs.26–30 = 0.72, 95%CI [0.67–0.77]), entry into care via PMTCT (AORentry_through_PMTCT_vs.VCT = 0.42, 95%CI [0.35–0.50]), marital status (AORmarried/in union_vs.single = 0.87, 95%CI [0.83–0.92]), education (AORsecondary_or_higher_vs.primary = 0.87, 95%CI [0.83–0.93]) and year of ART initiation were associated with a lower likelihood of late ART initiation. Clinic-level factors independently associated with a lower likelihood of late ART initiation included CD4 machine on-site (AORCD4_machine_onsite_vs.offsite = 0.83, 95%CI [0.74–0.94]) and presence of PMTCT services onsite (AOR = 0.85, 95%CI [0.77–0.93]). Conclusion: The risk of starting ART late remained persistently high. Efforts are needed to ensure identification and enrollment of patients at earlier stages of HIV disease. Individual and clinic level factors identified may provide clues for upstream structural interventions.

The pricing and procurement of antiretroviral drugs: an observational study of data from the Global Fund

The Purchase price report released in August 2004 by the Global Fund to Fight AIDS, Tuberculosis, and Malaria (Global Fund) was the first publication of a significant amount of real transaction purchase data for antiretrovirals (ARVs). We did an observational study of the ARV transaction data in the Purchase price report to examine the procurement behaviour of principal recipients of Global Fund grants in developing countries. We found that, with a few exceptions for specific products (e.g. lamivudine) and regions (e.g. eastern Europe), prices in low-income countries were broadly consistent or lower than the lowest differential prices quoted by the research and development sector of the pharmaceutical industry. In lower middle-income countries, prices were more varied and in several instances (lopinavir/ritonavir, didanosine, and zidovudine/lamivudine) were very high compared with the per capita income of the country. In all low- and lower middle-income countries, ARV prices were still significantly high given limited local purchasing power and economic strength, thus reaffirming the need for donor support to achieve rapid scale-up of antiretroviral therapy. However, the price of ARVs will have to decrease to render scale-up financially sustainable for donors and eventually for governments themselves. An important first step in reducing prices will be to make available in the public domain as much ARV transaction data as possible to provide a factual basis for discussions on pricing. The price of ARVs has considerable implications for the sustainability of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) treatment in the developing world.

The President's Emergency Plan for AIDS Relief — Is the Emergency Over?

On July 16, the Senate approved legislation that would increase the funding for the Presidents Emergency Plan for AIDS Relief (PEPFAR) to

Reframing HIV Care: Putting People at the Centre of Antiretroviral Delivery

48 billion for the next 5 years. Drs. Wafaa El-Sadr and David Hoos examine PEPFARs achievements, limitations, and lessons for the future. Dr. Wafaa El-Sadr discusses PEPFARs successes in addressing the HIV epidemic in the developing world, its broader effect on health care systems, and common criticisms of the program. Dr. El-Sadr is the director of the International Center for AIDS Care and Treatment Programs and a professor of clinical medicine and epidemiology at Columbia University, New York.

In vivo efficacy of artemether-lumefantrine and chloroquine against Plasmodium vivax: a randomized open label trial in central Ethiopia.

The delivery of HIV care in the initial rapid scale‐up of HIV care and treatment was based on existing clinic‐based models, which are common in highly resourced settings and largely undifferentiated for individual needs. A new framework for treatment based on variable intensities of care tailored to the specific needs of different groups of individuals across the cascade of care is proposed here. Service intensity is characterised by four delivery components: (i) types of services delivered, (ii) location of service delivery, (iii) provider of health services and (iv) frequency of health services. How these components are developed into a service delivery framework will vary across countries and populations, with the intention being to improve acceptability and care outcomes. The goal of getting more people on treatment before they become ill will necessitate innovative models of delivering both testing and care. As HIV programmes expand treatment eligibility, many people entering care will not be ‘patients’ but healthy, active and productive members of society . To take the framework to scale, it will be important to: (i) define which individuals can be served by an alternative delivery framework; (ii) strengthen health systems that support decentralisation, integration and task shifting; (iii) make the supply chain more robust; and (iv) invest in data systems for patient tracking and for programme monitoring and evaluation.

In vivo efficacy of artemether-lumefantrine against uncomplicated Plasmodium falciparum malaria in Central Ethiopia

Background In vivo efficacy assessments of antimalarials are essential for ensuring effective case management. In Ethiopia, chloroquine (CQ) without primaquine is the first-line treatment for Plasmodium vivax in malarious areas, but artemether-lumefantrine (AL) is also commonly used. Methods and Findings In 2009, we conducted a 42-day efficacy study of AL or CQ for P. vivax in Oromia Regional State, Ethiopia. Individuals with P. vivax monoinfection were enrolled. Primary endpoint was day 28 cure rate. In patients with recurrent parasitemia, drug level and genotyping using microsatellite markers were assessed. Using survival analysis, uncorrected patient cure rates at day 28 were 75.7% (95% confidence interval (CI) 66.8–82.5) for AL and 90.8% (95% CI 83.6–94.9) for CQ. During the 42 days of follow-up, 41.6% (47/113) of patients in the AL arm and 31.8% (34/107) in the CQ arm presented with recurrent P. vivax infection, with the median number of days to recurrence of 28 compared to 35 days in the AL and CQ arm, respectively. Using microsatellite markers to reclassify recurrent parasitemias with a different genotype as non-treatment failures, day 28 cure rates were genotype adjusted to 91.1% (95% CI 84.1–95.1) for AL and to 97.2% (91.6–99.1) for CQ. Three patients (2.8%) with recurrent parasitemia by day 28 in the CQ arm were noted to have drug levels above 100 ng/ml. Conclusions In the short term, both AL and CQ were effective and well-tolerated for P. vivax malaria, but high rates of recurrent parasitemia were noted with both drugs. CQ provided longer post-treatment prophylaxis than AL, resulting in delayed recurrence of parasitemia. Although the current policy of species-specific treatment can be maintained for Ethiopia, the co-administration of primaquine for treatment of P. vivax malaria needs to be urgently considered to prevent relapse infections. Trial Registration ClinicalTrials.gov NCT01052584

Antiretroviral therapy for prevention of HIV transmission: potential role for people who inject drugs in Central Asia.

BackgroundIn vivo efficacy assessments of the first-line treatments for Plasmodium falciparum malaria are essential for ensuring effective case management. In Ethiopia, artemether-lumefantrine (AL) has been the first-line treatment for uncomplicated P. falciparum malaria since 2004.MethodsBetween October and November 2009, we conducted a 42-day, single arm, open label study of AL for P. falciparum in individuals >6 months of age at two sites in Oromia State, Ethiopia. Eligible patients who had documented P. falciparum mono-infection were enrolled and followed according to the standard 2009 World Health Organization in vivo drug efficacy monitoring protocol. The primary and secondary endpoints were PCR uncorrected and corrected cure rates, as measured by adequate clinical and parasitological response on days 28 and 42, respectively.ResultsOf 4426 patients tested, 120 with confirmed falciparum malaria were enrolled and treated with AL. Follow-up was completed for 112 patients at day 28 and 104 patients at day 42. There was one late parasitological failure, which was classified as undetermined after genotyping. Uncorrected cure rates at both day 28 and 42 for the per protocol analysis were 99.1% (95% CI 95.1-100.0); corrected cure rates at both day 28 and 42 were 100.0%. Uncorrected cure rates at day 28 and 42 for the intention to treat analysis were 93.3% (95% CI 87.2-97.1) and 86.6% (95% CI 79.1-92.1), respectively, while the corrected cure rates at day 28 and 42 were 94.1% (95% CI 88.2-97.6) and 87.3% (95% CI 79.9-92.7), respectively. Using survival analysis, the unadjusted cure rate was 99.1% and 100.0% adjusted by genotyping for day 28 and 42, respectively. Eight P. falciparum patients (6.7%) presented with Plasmodium vivax infection during follow-up and were excluded from the per protocol analysis. Only one patient had persistent parasitaemia at day 3. No serious adverse events were reported, with cough and nausea/vomiting being the most common adverse events.ConclusionsAL remains a highly effective and well-tolerated treatment for uncomplicated falciparum malaria in the study setting after several years of universal access to AL. A high rate of parasitaemia with P. vivax possibly from relapse or new infection was observed.Trial RegistrationNCT01052584

Getting the balance right: Scaling-up treatment and prevention

Interest in the use of antiretroviral therapy (ART) for prevention stems from mounting evidence from research studies demonstrating that ART is associated with a decrease in sexual HIV transmission among serodiscordant couples and, perhaps, in other populations at risk. There is paucity of data on the efficacy of ART for prevention in key populations, including persons who inject drugs (PWID). In this paper, we examine the current status of HIV services for PWID in Central Asia, the use of ART by this population and explore ART for prevention for PWID in this context. We also discuss research and implementation questions with relevance to such a strategy in the region.