High-Level Cross-Resistance to Didanosine Observed in South African Children Failing an Abacavir- or Stavudine-Based 1st-Line Regimen

Background

The knowledge-base of emerging drug resistance profiles in children exposed to abacavir-based antiretroviral regimens in South Africa is very limited. This study investigated the suitability of didanosine-based 2^nd-line regimens for children in the context of antiretroviral drug resistance patterns emerging after 1^st-line virologic failure.

Methods

A retrospective dataset of 354 antiretroviral drug resistant genotypes from children failing either abacavir (n = 81) or stavudine (n = 273) based 1^st-line regimens, was analysed. Samples were sent to the HIV genotyping laboratory at Charlotte Maxeke Johannesburg Academic Hospital, for routine testing. Pol sequences were submitted to the Stanford HIV drug resistance database for genotypic predictions.

Results

Children were exposed to abacavir or stavudine-based 1^st-line regimens for an average of 21 and 36 months, respectively. The frequency of reduced susceptibility to didanosine was substantial in the abacavir-exposed group (69.1%).This reduced susceptibility was commonly attributed to L74V/I (n = 44) and to a lesser extent K65R (n = 10) mutations. Didanosine resistance was observed in 43.2% of patients exposed to stavudine-based regimens. In contrast, most children remained susceptible to stavudine regardless of exposure to abacavir (77.8%) or stavudine (74.7%). At least 80% of children remained susceptible to zidovudine irrespective of stavudine or abacavir-exposure. The presence of the K65R mutation was more common after abacavir pressure (12.3% vs 1.8%).

Conclusion

Analysis revealed that didanosine-based 2^nd-line regimens have limitations for South African children, given the high frequency of mutations that confer cross-resistance to didanosine; especially after abacavir-exposure. This data has influenced South African paediatric treatment guidelines, which now recommend zidovudine-based 2^nd-line regimens.     

HIV Drug Resistance Early Warning Indicators in Namibia for Public Health Action

Background

HIV drug resistance (HIVDR) testing is not routinely available in many resource-limited settings, therefore antiretroviral therapy (ART) program and site factors known to be associated with emergence of HIVDR should be monitored to optimize the quality of patient care and minimize the emergence of preventable HIVDR.

Methods

In 2010, Namibia selected five World Health Organization Early Warning Indicators (EWIs) and scaled-up monitoring from 9 to 33 ART sites: ART prescribing practices, Patients lost to follow-up (LTFU) at 12 months, Patients switched to a second-line regimen at 12 months, On-time antiretroviral (ARV) drug pick-up, and ARV drug-supply continuity.

Results

Records allowed reporting on three of the five selected EWIs. 22 of 33 (67%) sites met the target of 100% initiated on appropriate first-line regimens. 17 of 33 (52%) sites met the target of ≤20% LTFU. 15 of 33 (45%) sites met the target of 0% switched to a second-line regimen.

Conclusions

EWI monitoring directly resulted in public health action which will optimize the quality of care, specifically the strengthening of ART record systems, engagement of ART sites, and operational research for improved adherence assessment and ART patient defaulter tracing.     

Nevirapine-Associated Early Hepatotoxicity: Incidence,Risk Factors,and Associated Mortality in a Primary Care ART Programme in South Africa

Background

The majority of antiretroviral treatment programmes in sub-Saharan Africa are scaling up antiretroviral treatment using a fixed dose first-line antiretroviral regimen containing stavudine, lamivudine, and nevirapine. One of the primary concerns with the use of this regimen is nevirapine-associated hepatotoxicity.

Methodology/Principal Findings

Study participants were 1809 HIV-infected, antiretroviral naïve adults initiating nevirapine-based antiretroviral therapy between November 2002 and December 2006. The primary outcome was early hepatotoxicity. Secondary outcomes were associations with hepatotoxicity and mortality at six months. The cumulative proportion of early hepatotoxicity ranged from 1.0–2.0% giving an incidence-rate at 102 days of 3.6–7.6 per 100 person-years. Median time to hepatotoxicity was 32 (IQR 28–58) days. At 12 weeks, only 8% of patients had alanine aminotransferase monitoring at all the time-points recommended by national guidelines. No association was found between age, gender, baseline CD4 count, concurrent tuberculosis infection, prior participation in a prevention of mother-to-child-transmission program, or baseline weight and early hepatotoxicity. There was no association between early hepatotoxicity and mortality.

Conclusions

The cumulative proportion of early hepatotoxicity in nevirapine based antiretroviral therapy was low in this resource-constrained setting. Hepatotoxicity was not associated with mortality. Frequent routine monitoring of alanine aminotransferase proved difficult to implement in this public sector primary care programme. Focused monitoring in the first month may be a more cost-effective and pragmatic option in settings with limited resources. Correlation with clinical signs and symptoms may allow future alanine aminotransferase testing to be dictated by clinical criteria.     

Incidence and Predictors of First Line Antiretroviral Regimen Modification in Western Kenya

Background

Limited antiretroviral treatment regimens in resource-limited settings require long-term sustainability of patients on the few available options. We evaluated the incidence and predictors of combined antiretroviral treatment (cART) modifications, in an outpatient cohort of 955 patients who initiated cART between January 2009 and January 2011 in western Kenya.

Methods

cART modification was defined as either first time single drug substitution or switch. Incidence rates were determined by Poisson regression and risk factor analysis assessed using multivariate Cox regression modeling.

Results

Over a median follow-up period of 10.7 months, 178 (18.7%) patients modified regimens (incidence rate (IR); 18.6 per 100 person years [95% CI: 16.2–21.8]). Toxicity was the most common cited reason (66.3%). In adjusted multivariate Cox piecewise regression model, WHO disease stage III/IV (aHR; 1.82, 95%CI: 1.25–2.66), stavudine (d4T) use (aHR; 2.21 95%CI: 1.49–3.30) and increase in age (aHR; 1.02, 95%CI: 1.0–1.04) were associated with increased risk of treatment modification within the first year post-cART. Zidovudine (AZT) and tenofovir (TDF) use had a reduced risk for modification (aHR; 0.60 95%CI: 0.38–0.96 and aHR; 0.51 95%CI: 0.29–0.91 respectively). Beyond one year of treatment, d4T use (aHR; 2.75, 95% CI: 1.25–6.05), baseline CD4 counts ≤350 cells/mm³ (aHR; 2.45, 95%CI: 1.14–5.26), increase in age (aHR; 1.05 95%CI: 1.02–1.07) and high baseline weight >60kg aHR; 2.69 95% CI: 1.58–4.59) were associated with risk of cART modification.

Conclusions

Early treatment initiation at higher CD4 counts and avoiding d4T use may reduce treatment modification and subsequently improve sustainability of patients on the available limited options.     

Stavudine Toxicity in Adult Longer-Term ART Patients in Blantyre, Malawi

Background

Stavudine is an effective and inexpensive antiretroviral drug, but no longer recommended by WHO for first-line antiretroviral regimens in resource-limited settings due to toxicity concerns. Because of the high cost of alternative drugs, it has not been feasible to replace stavudine in most adults in the Malawi ART programme. We aimed to provide policy makers with a detailed picture of stavudine toxicities in Malawians on longer-term ART, in order to facilitate prioritization of stavudine replacement among other measures to improve the quality of ART programmes.

Methods

Prospective cohort of Malawian adults who had just completed one year of stavudine containing ART in an urban clinic, studying peripheral neuropathy, lipodystrophy, diabetes mellitus, high lactate syndromes, pancreatitis and dyslipidemia during 12 months follow up. Stavudine dosage was 30 mg irrespective of weight. Cox regression was used to determine associations with incident toxicities.

Results

253 patients were enrolled, median age 36 years, 62.5% females. Prevalence rates (95%-confidence interval) of toxicities after one year on stavudine were: peripheral neuropathy 21.3% (16.5–26.9), lipodystrophy 14.7% (2.4–8.1), high lactate syndromes 0.0% (0–1.4), diabetes mellitus 0.8% (0–2.8), pancreatitis 0.0% (0–1.5). Incidence rates per 100 person-years (95%-confidence interval) during the second year on stavudine were: peripheral neuropathy 19.8 (14.3–26.6), lipodystrophy 11.4 (7.5–16.3), high lactate syndromes 2.1 (0.7–4.9), diabetes mellitus 0.4 (0.0–1.4), pancreatitis 0.0 (0.0–0.2). Prevalence of hypercholesterolemia and hypertriglyceridemia increased from 12.1% to 21.1% and from 29.5% to 37.6% respectively between 12 and 24 months. 5.5% stopped stavudine, 1.3% died and 4.0% defaulted during follow up. Higher age was an independent risk factor for incident peripheral neuropathy and lipodystrophy.

Conclusion

Stavudine associated toxicities continued to accumulate during the second year of ART, especially peripheral neuropathy and lipodystrophy and more so at increasing age. Our findings support investments for replacing stavudine in first-line regimens in sub-Saharan Africa.     

Week 120 Efficacy of Tenofovir,Lamivudine and Lopinavir/r-Based Second-Line Antiretroviral Therapy in Treatment-Experienced HIV Patients

Background

Tenofovir (TDF) and ritonavir-boosted lopinavir (LPV/r) were not introduced to China as second-line medications until 2009. The efficacy and safety of TDF/3TC/LPV/r based second-line regimen have not been evaluated in Chinese HIV patients who failed first-line regimens.

Methods

This was a multicenter cohort study recruiting patients from Beijing, Shanghai, Guangdong, and Henan provinces between November 2008 and January 2010. Eighty HIV infected patients failing first-line regimens with serum creatinine lower than 1.5 times the upper limit of normal received TDF+ lamivudine (3TC)+ LPV/r were followed up for 120 weeks. CD4 cell count, viral load, and estimated glomerular filtration rate (eGFR) were monitored at each visit.

Results

At baseline, 31.2% and 48.8% of patients had moderate/high-level resistance to TDF and 3TC, respectively; while 2.5% of patients had only low-level resistance to LPV/r. During 120 weeks of follow-up, virological suppression rate reached over 70% (<40 copies/ml) and 90% (<400 copies/ml), and median CD4 cell count increased from 157 cells/μL at baseline to 307 cells/μL at week 120. Baseline drug-resistance mutations had no impact on the efficacy of second-line antiretroviral therapy. Median eGFR dropped from 104.7 ml/min/1.73m² at baseline to 95.6 ml/min/1.73m² at week 24 and then recovered after week 96.

Conclusion

This study for the first time demonstrated that TDF+ 3TC+ LPV/r was efficacious as second-line regimen with acceptable nephrotoxicity profiles in patients who failed zidovudine or stavudine based first-line regimens in China.

Trial Registration

ClinicalTrials.gov NCT00872417     

Sustained Virological Response on Second-Line Antiretroviral Therapy following Virological Failure in HIV-Infected Patients in Rural South Africa

Objective

This study aims to describe the virological, immunological and clinical efficacy of protease inhibitor (PI)-based second-line antiretroviral therapy (ART) in rural South Africa.

Methods

An observational cohort study was performed on 210 patients (including 39 children) who initiated PI-based second-line therapy at least 12 months prior to data collection. Biannual clinical, immunological and virological monitoring was performed. Primary endpoints were adequate virological response (plasma HIV-1 RNA<400 copies/ml), full virological suppression (plasma HIV-1 RNA<50 copies/ml) and treatment failure (virological failure (plasma HIV-1 RNA>1000 after initial virological response) or on-going viremia (plasma HIV-1 RNA never<400 copies/ml for more than six months)). Data were analyzed by an on-treatment (OT) and intention-to-treat (ITT) approach. Analyses were primarily performed on the group of patients who switched following first-line virological failure.

Results

Median duration of follow-up after switch to second-line treatment was 20 months [IQR 11–35]. 191 patients had switched to second-line ART due to first-line virological failure. 139/191 of them (72.8%, ITT) were in care and on treatment at the end of follow-up and 11/191 (5.8%, ITT) had died. After twelve months, an adequate virological response was seen in 92/128 patients (71.9%, OT), of which 78/128 (60.9%, OT) experienced full virological suppression. Virological response remained stable after 24 months. Virological efficacy was similar amongst adult and pediatric patients. As in first-line ART, we observed a lack of correlation between virological failure and WHO-defined immunological failure.

Conclusions

Good virological outcomes following first-line failure can be achieved with PI-based, second-line antiretroviral therapy in both adult and pediatric patients in rural South Africa. Retention rates were high and virological outcomes were sustainable during the two-year follow-up period, although persisting low-level viremia occurred in a subset of patients. The observed viro-immunological dissociation emphasizes the need for virological monitoring.     

Persistent Difficulties in Switching to Second-Line ART in Sub-Saharan Africa — A Systematic Review and Meta-Analysis

Objectives

Switching to second-line antiretroviral therapy (ART) largely depends on careful clinical assessment and access to biological measurements. We performed a systematic review and meta-analysis to estimate the incidence of switching to second-line ART in sub-Saharan Africa and its main programmatic determinants.

Methods

We searched 2 databases for studies reporting the incidence rate of switching to second-line ART in adults living in sub-Saharan Africa. Data on the incidence rate of switching were pooled, and random-effect models were used to evaluate the effect of factors measured at the programme level on this incidence rate.

Results

Nine studies (157,340 patients) in 21 countries were included in the meta-analysis. All studies considered patients under first-line ART and conditions to initiate ART were similar across studies. Overall, 3,736 (2.4%) patients switched to second-line ART. Incidence rate of switch was in mean 2.65 per 100 person-years (PY) (95% confidence interval: 2.01–3.30); it ranged from 0.42 to 4.88 per 100 PY and from 0 to 4.80 per 100 PY in programmes with and without viral load monitoring, respectively. No factors measured at the programme level were associated with the incidence rate of switching to second-line ART.

Conclusion

The low incidence rate of switching to second-line ART suggests that the monitoring of patients under ART is challenging and that access to second-line ART is ineffective; efforts should be made to increase access to second-line ART to those in need by providing monitoring tools, education and training, as well as a more convenient regimen.     

Raltegravir Cerebrospinal Fluid Concentrations in HIV-1 Infection

Introduction

Raltegravir is an HIV-1 integrase inhibitor currently used in treatment-experienced HIV-1-infected patients resistant to other drug classes. In order to assess its central nervous system penetration, we measured raltegravir concentrations in cerebrospinal fluid (CSF) and plasma in subjects receiving antiretroviral treatment regimens containing this drug.

Methods

Raltegravir concentrations were determined by liquid chromatography tandem mass spectrometry in 25 paired CSF and plasma samples from 16 HIV-1-infected individuals. The lower limit of quantitation was 2.0 ng/ml for CSF and 10 ng/ml for plasma.

Results

Twenty-four of the 25 CSF samples had detectable raltegravir concentrations with a median raltegravir concentration of 18.4 ng/ml (range, <2.0–126.0). The median plasma raltegravir concentration was 448 ng/ml (range, 37–5180). CSF raltegravir concentrations correlated with CSF:plasma albumin ratios and CSF albumin concentrations.

Conclusions

Approximately 50% of the CSF specimens exceeded the IC₉₅ levels reported to inhibit HIV-1 strains without resistance to integrase inhibitors. In addition to contributing to control of systemic HIV-1 infection, raltegravir achieves local inhibitory concentrations in CSF in most, but not all, patients. Blood-brain and blood-CSF barriers likely restrict drug entry, while enhanced permeability of these barriers enhances drug entry.     

Effectiveness of Multidrug Antiretroviral Regimens to Prevent Mother-to-Child Transmission of HIV-1 in Routine Public Health Services in Cameroon

Background

Multidrug antiretroviral (ARV) regimens including HAART and short-course dual antiretroviral (sc-dARV) regimens were introduced in 2004 to improve Prevention of Mother-to-Child Transmission (PMTCT) in Cameroon. We assessed the effectiveness of these regimens from 6–10 weeks and 12 months of age, respectively.

Methodology/Findings

We conducted a retrospective cohort study covering the period from October 2004 to March 2008 in a reference hospital in Cameroon. HIV-positive pregnant women with CD4 ≤350 cells/mm³ received first-line HAART [regimen 1] while the others received ARV prophylaxis including sc-dARV or single dose nevirapine (sd-NVP). Sc-dARV included at least two drugs according to different gestational ages: zidovudine (ZDV) from 28–32 weeks plus sd-NVP [regimen 2], ZDV and lamuvidine (3TC) from 33–36 weeks plus sd-NVP [regimen 3]. When gestational age was ≥37 weeks, women received sd-NVP during labour [regimen 4]. Infants received sd-NVP plus ZDV and 3TC for 7 days or 30 days. Early diagnosis (6–10 weeks) was done, using b-DNA and subsequently RT-PCR. We determined early MTCT rate and associated risk factors using logistic regression. The 12-month HIV-free survival was assessed using Cox regression. Among 418 mothers, 335 (80%) received multidrug ARV regimens (1, 2, and 3) and MTCT rate with multidrug regimens was 6.6% [95%CI: 4.3–9.6] at 6 weeks, without any significant difference between regimens. Duration of mother''s ARV regimen <4 weeks [OR = 4.7, 95%CI: 1.3–17.6], mother''s CD4 <350 cells/mm³ [OR = 6.4, 95%CI: 1.8–22.5] and low birth weight [OR = 4.0, 95%CI: 1.4–11.3] were associated with early MTCT. By 12 months, mixed feeding [HR = 8.7, 95%CI: 3.6–20.6], prematurity [HR = 2.3, 95%CI: 1.2–4.3] and low birth weight were associated with children''s risk of progressing to infection or death.

Conclusions

Multidrug ARV regimens for PMTCT are feasible and effective in routine reference hospital. Early initiation of ARV during pregnancy and proper obstetrical care are essential to improve PMTCT.     

Multidrug-resistant tuberculosis treatment outcomes in Karakalpakstan, Uzbekistan: treatment complexity and XDR-TB among treatment failures

Background

A pilot programme to treat multidrug-resistant TB (MDR-TB) was implemented in Karakalpakstan, Uzbekistan in 2003. This region has particularly high levels of MDR-TB, with 13% and 40% among new and previously treated cases, respectively.

Methodology

This study describes the treatment process and outcomes for the first cohort of patients enrolled in the programme, between October 2003 and January 2005. Confirmed MDR-TB cases were treated with an individualised, second-line drug regimen based on drug susceptibility test results, while suspected MDR-TB cases were treated with a standardised regimen pending susceptibility results.

Principal Findings

Of 108 MDR-TB patients, 87 were started on treatment during the study period. Of these, 33 (38%) were infected with strains resistant to at least one second-line drug at baseline, but none had initial ofloxacin resistance. Treatment was successful for 54 (62%) patients, with 13 (15%) dying during treatment, 12 (14%) defaulting and 8 (8%) failing treatment. Poor clinical condition and baseline second-line resistance contributed to treatment failure or death. Treatment regimens were changed in 71 (82%) patients due to severe adverse events or drug resistance. Adverse events were most commonly attributed to cycloserine, ethionamide and p-aminosalicylic acid. Extensively drug resistant TB (XDR-TB) was found among 4 of the 6 patients who failed treatment and were still alive in November 2006.

Conclusions

While acceptable treatment success was achieved, the complexity of treatment and the development of XDR-TB among treatment failures are important issues to be addressed when considering scaling up MDR-TB treatment.     

The Prevalence of HIV-1 Drug Resistance among Antiretroviral Treatment Na?ve Individuals in Mainland China: A Meta-Analysis

Background

Surveillance of drug resistance in antiretroviral treatment-naïve patients in China is needed to ensure optimal treatment outcomes and control of the human immunodeficiency virus (HIV) epidemic.

Methods

A systematic literature search was conducted in English and Chinese through PubMed (English), China National Knowledge Infrastructure (Chinese), Chinese Biomedical Literature Database (Chinese), and Wanfang (Chinese). Random effects models were used to calculate the pooled prevalence of transmitted drug resistance and subgroup analyses examined prevalence estimates across time periods, study locations, and study populations.

Results

Analysis of data from 71 studies (47 in Chinese and 24 in English) yielded a pooled prevalence of transmitted HIV drug resistance to any antiretroviral drug class of 3.64% (95% confidence interval [CI]: 3.00%–4.32%). Rates were significantly high at initial stage of free ART program from 2003 to 2005 (5.18%, 95%CI: 3.13%–7.63%), and were much lower among studies conducted in 2006–2008 (3.02%, 95%CI: 2.03%–4.16%). A slight increase was observed again in the most recent study period from 2009 to 2012 (3.68%, 95%CI: 2.78%–4.69%). Subgroup analysis revealed highest prevalence levels of transmitted drug resistance in Beijing city, and Henan and Hubei provinces (above 5%), and although differences in prevalence rates among risk groups were negligible, men who have sex with men were unique in their relatively large portion of protease inhibitor resistance, a second-line drug of limited availability in China.

Conclusions

Overall prevalence of transmitted HIV drug resistance in China is classified as “low” by the World Health Organization. However regional and temporal variability suggest a more complex epidemic for which closer HIV drug resistance surveillance is needed. A nationwide HIV drug resistance surveillance system to monitor both treatment-experienced and treatment-naïve patients will be a cornerstone to ensure the effectiveness of treatment scale-up, particularly as China seeks to expand a national policy of antiretroviral treatment as prevention.     

Impact of Previous Virological Treatment Failures and Adherence on the Outcome of Antiretroviral Therapy in 2007

Background

Combination antiretroviral treatment (cART) has been very successful, especially among selected patients in clinical trials. The aim of this study was to describe outcomes of cART on the population level in a large national cohort.

Methods

Characteristics of participants of the Swiss HIV Cohort Study on stable cART at two semiannual visits in 2007 were analyzed with respect to era of treatment initiation, number of previous virologically failed regimens and self reported adherence. Starting ART in the mono/dual era before HIV-1 RNA assays became available was counted as one failed regimen. Logistic regression was used to identify risk factors for virological failure between the two consecutive visits.

Results

Of 4541 patients 31.2% and 68.8% had initiated therapy in the mono/dual and cART era, respectively, and been on treatment for a median of 11.7 vs. 5.7 years. At visit 1 in 2007, the mean number of previous failed regimens was 3.2 vs. 0.5 and the viral load was undetectable (<50 copies/ml) in 84.6% vs. 89.1% of the participants, respectively. Adjusted odds ratios of a detectable viral load at visit 2 for participants from the mono/dual era with a history of 2 and 3, 4, >4 previous failures compared to 1 were 0.9 (95% CI 0.4–1.7), 0.8 (0.4–1.6), 1.6 (0.8–3.2), 3.3 (1.7–6.6) respectively, and 2.3 (1.1–4.8) for >2 missed cART doses during the last month, compared to perfect adherence. From the cART era, odds ratios with a history of 1, 2 and >2 previous failures compared to none were 1.8 (95% CI 1.3–2.5), 2.8 (1.7–4.5) and 7.8 (4.5–13.5), respectively, and 2.8 (1.6–4.8) for >2 missed cART doses during the last month, compared to perfect adherence.

Conclusions

A higher number of previous virologically failed regimens, and imperfect adherence to therapy were independent predictors of imminent virological failure.     

Development and Validation of a Composite Programmatic Assessment Tool for HIV Therapy

Background

We developed and validated a new and simple metric, the Programmatic Compliance Score (PCS), based on the IAS-USA antiretroviral therapy management guidelines for HIV-infected adults, as a predictor of all-cause mortality, at a program-wide level. We hypothesized that non-compliance would be associated with the highest probability of mortality.

Methods and Findings

3543 antiretroviral-naive HIV-infected patients aged ≥19 years who initiated antiretroviral therapy between January 1, 2000 and August 31, 2009 in British Columbia (BC), Canada, were followed until August 31, 2010. The PCS is composed by six non-performance indicators based on the IAS-USA guidelines: (1) having <3 CD4 count tests in the first year after starting antiretroviral therapy; (2) having <3 plasma viral load tests in the first year after starting antiretroviral therapy; (3) not having drug resistance testing done prior to starting antiretroviral therapy; (4) starting on a non-recommended antiretroviral therapy regimen; (5) starting therapy with CD4 <200 cells/mm³; and (6) not achieving viral suppression within 6 months since antiretroviral therapy initiation. The sum of these six indicators was used to develop the PCS score - higher score indicates poorer performance. The main outcome was all-cause mortality. Each PCS component was independently associated with mortality. In the mortality analysis, the odds ratio (OR) for PCS ≥4 versus 0 was 22.37 (95% CI 10.46–47.84).

Conclusions

PCS was strongly associated with all-cause mortality. These results lend independent validation to the IAS-USA treatment guidelines for HIV-infected adults. Further efforts are warranted to enhance the PCS as a means to further improve clinical outcomes. These should be specifically evaluated and targeted at healthcare providers and patients.     

Long-term costs and health impact of continued global fund support for antiretroviral therapy

Background

By the end of 2011 Global Fund investments will be supporting 3.5 million people on antiretroviral therapy (ART) in 104 low- and middle-income countries. We estimated the cost and health impact of continuing treatment for these patients through 2020.

Methods and Findings

Survival on first-line and second-line ART regimens is estimated based on annual retention rates reported by national AIDS programs. Costs per patient-year were calculated from country-reported ARV procurement prices, and expenditures on laboratory tests, health care utilization and end-of-life care from in-depth costing studies. Of the 3.5 million ART patients in 2011, 2.3 million will still need treatment in 2020. The annual cost of maintaining ART falls from $1.9 billion in 2011 to $1.7 billion in 2020, as a result of a declining number of surviving patients partially offset by increasing costs as more patients migrate to second-line therapy. The Global Fund is expected to continue being a major contributor to meeting this financial need, alongside other international funders and domestic resources. Costs would be $150 million less in 2020 with an annual 5% decline in first-line ARV prices and $150–370 million less with a 5%–12% annual decline in second-line prices, but $200 million higher in 2020 with phase out of stavudine (d4T), or $200 million higher with increased migration to second-line regimens expected if all countries routinely adopted viral load monitoring. Deaths postponed by ART correspond to 830,000 life-years saved in 2011, increasing to around 2.3 million life-years every year between 2015 and 2020.

Conclusions

Annual patient-level direct costs of supporting a patient cohort remain fairly stable over 2011–2020, if current antiretroviral prices and delivery costs are maintained. Second-line antiretroviral prices are a major cost driver, underscoring the importance of investing in treatment quality to improve retention on first-line regimens.     

Hidden Drug Resistant HIV to Emerge in the Era of Universal Treatment Access in Southeast Asia

Background

Universal access to first-line antiretroviral therapy (ART) for HIV infection is becoming more of a reality in most low and middle income countries in Asia. However, second-line therapies are relatively scarce.

Methods and Findings

We developed a mathematical model of an HIV epidemic in a Southeast Asian setting and used it to forecast the impact of treatment plans, without second-line options, on the potential degree of acquisition and transmission of drug resistant HIV strains. We show that after 10 years of universal treatment access, up to 20% of treatment-naïve individuals with HIV may have drug-resistant strains but it depends on the relative fitness of viral strains.

Conclusions

If viral load testing of people on ART is carried out on a yearly basis and virological failure leads to effective second-line therapy, then transmitted drug resistance could be reduced by 80%. Greater efforts are required for minimizing first-line failure, to detect virological failure earlier, and to procure access to second-line therapies.