The case for viral load testing in adolescents in resource-limited settings

INTRODUCTION

The success of HIV treatment programmes globally has resulted in children with perinatally acquired HIV reaching adolescence in large numbers. The number of adolescents living with HIV is growing further due to persisting high HIV incidence rates among adolescents in low- and middle-income settings, particularly in sub-Saharan Africa. Although expanding access to HIV viral load monitoring is necessary to achieve the 90-90-90 targets across the HIV care continuum, implementation is incomplete. We discuss the rationale for prioritizing viral load monitoring among adolescents and the associated challenges.

DISCUSSION

Adolescents with HIV are a complex group to treat successfully due to extensive exposure to antiretroviral therapy for those with perinatally acquired HIV and the challenges in sustained medication adherence in this age group. Given the high risk of treatment failure among adolescents and the limited drug regimens available in limited resource settings, HIV viral load monitoring in adolescents could prevent unnecessary and costly switches to second-line therapy in virologically suppressed adolescents. Because adolescents living with HIV may be heavily treatment experienced, have suboptimal treatment adherence, or may be on second or even third-line therapy, viral load testing would allow clinicians to make informed decisions about increased counselling and support for adolescents together with the need to maintain or switch therapeutic regimens.

CONCLUSIONS

Given scarce resources, prioritization of viral load testing among groups with a high risk of virological failure may be required. Adolescents have disproportionately high rates of virological failure, and targeting this age group for viral load monitoring may provide valuable lessons to inform broader scale-up.

Incidence and associated factors of pulmonary tuberculosis in HIV-infected children after highly active antiretroviral therapy (HAART) in China: a retrospective study

China is a country with high tuberculosis (TB) incidence but relatively low HIV prevalence. However, due to difficulties in diagnosis and reporting, true burden of HIV-associated TB in children is unknown. The objective of this study was to describe the incidence of pulmonary TB (PTB) after antiretroviral therapy (ART) and to study risk factors. A retrospective study was performed based on routinely collected data from China national pediatric free antiretroviral treatment database. A total of 3365 children under 15 years on ART from July 2005 to October 2012 were included. Multivariable logistic regression was used to detect associated factors. Two thousand nine hundred and ninety (89%) children got infected from HIV-positive mother, with median age of 6.7 (4.1, 10.0) years at highly active antiretroviral therapy (HAART) initiation in this program. Seventy-seven (2.3%) children were diagnosed with PTB after ART during 7.3 years cohort observation. Median time of occurrence was 212 (30-514) days. Overall incidence was 0.83 (0.65-1.01)/100 person-years (py), with the peak of 3.6/100 py in the first 3 months after antiretroviral treatment. WHO stage IV at baseline showed 2 (95% CI 1.0-6.8) times more risk for developing TB. Late clinical stage at ART initiation was shown to relate with TB incidence. PTB coinfection leads to higher mortality. Early diagnosis and treatment of HIV are highly required to reduce HIV-associated morbidity and mortality due to TB.

Antiretroviral drug resistance profiles and response to second-line therapy among HIV type 1-infected Ugandan children

We sought to determine the pattern of resistance-associated mutations (RAMs) among HIV-1-infected children failing first-line antiretroviral therapy (ART) and ascertain their response to second-line regimens in 48 weeks of follow-up. The design involved a cohort study within an HIV care program. We studied records of 142 children on ART with virological failure to first-line ART and switched to second-line ART with prior genotypic resistance testing. The pattern of RAMs was determined in frequency runs and the factors associated with accumulation of≥3 thymidine analogue mutations (TAMs) and K103N were determined using multivariate logistic models. Changes in weight, height, CD4, and viral load at weeks 24 and 48 after switch to second-line therapy were determined using descriptive statistics. The children were mean age 10.9±4.6 years and 55.6% were male. The commonest nucleoside reverse transcriptase inhibitor (NRTI) RAM was M184V in 129/142 (90.8%) children. TAMs,≥3 TAMs, 69 insertion complex, K65R/N, and Q151M were observed in 43.0%, 10.6%, 18.3%, 2.8%, and 2.1% of the children, respectively. The commonest nonnucleoside reverse transcriptase inhibitor (NNRTI) RAM was K103N in 72/142 (50.7%) children. The starting ART regimen was associated with accumulation of both≥3 TAMs (p=0.046) and K103N (p<0.0001), while a history of poor adherence was associated with K103N accumulation (p=0.0388). After 24 weeks and 48 weeks of follow-up on lopinavir-ritonavir based second-line ART, 86/108 (79.6%) and 84.5% (87/103) of the children had viral loads<400 copies/ml, respectively. The mean CD4 absolute count increased by 173 cells/μl and 267cells/μl at weeks 24 and 48, respectively. Increments were also observed in mean weight (1.6 kg and 4.3 kg) and height (1.8 cm and 5.8 cm) at weeks 24 and 48, respectively. Multiple RAMs were observed among HIV-1-infected children with virological failure on first-line ART with M184V and K103N most frequent. The children responded favorably to boosted PI-based second-line ART.

Drug resistance profiles among HIV-1-infected children experiencing delayed switch and 12-month efficacy after using second-line antiretroviral therapy: an observational cohort study in rural China

OBJECTIVE

To analyze the genotypic resistance profiles of HIV-infected children from rural China who were experiencing virologic failure to first-line antiretroviral therapy regimens and to evaluate 1-year regimen efficacy after switching to second-line therapy.

METHODS

A prospective cohort study was performed. Seventy-six children from the first rural pilot program with HIV viral load >1000 copies per milliliter on 2 consecutive occasions were studied. We analyzed genotype results and observed second-line therapy efficacy to 12 months.

RESULTS

After 33.1 (23.3, 41.1) months on first-line treatment after enrollment into national program, 98.7% of genotyped patients developed high-level resistance to nevirapine and 81.6% of patients had high-level resistance to efavirenz. High-level resistance to lamivudine was observed in 82.9%, followed by 57.9% for stavudine and 52.6% for zidovudine. In the nonnucleoside reverse transcriptase inhibitor class, the most common mutations were K103N/S at 50% and Y181C/I at 48.7%. M184V/I was the most common nucleoside reverse transcriptase inhibitor resistance mutation at 77.6%, the mutation rate for ≥3 thymidine analogue mutations, Q151M, and K65R were 33%, 12%, and 9%, respectively. After 12 months of boosted protease inhibitor-based second-line therapy, CD4 counts had on average increased 256 cells per cubic millimeter compared with switch baseline and 83.1% of patients had undetectable viral loads (<50 copies/mL).

CONCLUSIONS

HIV-1-infected children who continued their first-line regimen regardless of virologic failure harbored multiple resistance mutations. Although the extent of resistance to nucleoside reverse transcriptase inhibitor class drugs would be expected to limit subsequent treatment options, the current second-line regimen remained effective during a 1-year observational period.

HIV-1-resistance-associated mutations after failure of first-line antiretroviral treatment among children in resource-poor regions: a systematic review

HIV-positive children are at high risk of drug resistance, which is of particular concern in settings where antiretroviral options are limited. In this Review we explore resistance rates and patterns among children in developing countries in whom antiretroviral treatment has failed. We did a systematic search of online databases and conference abstracts and included studies reporting HIV-1 drug resistance after failure of first-line paediatric regimens in children (<18 years) in resource-poor regions (Latin America, Africa, and Asia). We retrieved 1312 citations, of which 30 studies reporting outcomes in 3241 children were eligible. Viruses with resistance-associated mutations were isolated from 90% (95% CI 88-93%) of children. The prevalence of mutations associated with nucleoside reverse transcriptase inhibitors was 80%, with non-nucleoside reverse transcriptase inhibitors was 88%, and with protease inhibitors was 54%. Methods to prevent treatment failure, including adequate paediatric formulations and affordable salvage treatment options are urgently needed.

Progress of the National Pediatric Free Antiretroviral Therapy program in China

In 2003, the Chinese Government initiated a free antiretroviral therapy (ART) program focusing on adult AIDS patients. Pediatric antiretroviral (ARV) formulations were yet unavailable. It was not until July 2005, with the initiation of a two-stage program implemented by the Chinese Ministry of Health, that pediatric formulations became accessible in China. Initially, the pediatric ART program was piloted in six provinces with the highest incidences of pediatric HIV/AIDS. The pilot stage allowed the Chinese Center for Disease Control and Prevention (CCDC) to finalize entry criteria, treatment regimen, and patient monitoring and follow-up procedures. The second stage commenced at the end of 2006 when the program was scaled-up nationally. In order to guarantee treatment of pediatric patients, extensive training in the selection of appropriate ARV drug regimen and dosage was provided to doctors, often through on-site collaboration with domestic and international experts. The CCDC simultaneously established a pediatric ARV management system and a pediatric ART information system. CD4 count and other laboratory tests are being routinely performed on these pediatric patients. By the end of June 2009, 1529 pediatric patients had received ARV under the national program. However, challenges remain. Firstly, many children infected with HIV/AIDS live in rural areas where the treatment quality is hindered by the limited number of medical facilities and skilled medical workers. Secondly, much of the pediatric ARV drug supply depends on donation. An effort needs to be made by the Chinese Government to establish China's own drug procurement and supply system.

Drug resistance is widespread among children who receive long-term antiretroviral treatment at a rural Tanzanian hospital

Objectives

To assess long-term virological efficacy and the emergence of drug resistance in children who receive antiretroviral treatment (ART) in rural Tanzania.

Patients and methods

Haydom Lutheran Hospital has provided ART to HIV-infected individuals since 2003. From February through May 2009, a cross-sectional virological efficacy survey was conducted among children (<15 years) who had completed ≥6 months of first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-based ART. Genotypic resistance was determined in those with a viral load of >200 copies/mL.

Results

Virological response was measured in 19 of 23 eligible children; 8 of 19 were girls and median age at ART initiation was 5 years (range 2–14 years). Median duration of ART at the time of the survey was 40 months (range 11–61 months). Only 8 children were virologically suppressed (≤40 copies/mL), whereas 11 children had clinically relevant resistance mutations in the reverse transcriptase gene. The most frequent mutations were M184V (n = 11), conferring resistance to lamivudine and emtricitabine, and Y181C (n = 4), G190A/S (n = 4) and K103N (n = 4), conferring resistance to NNRTIs. Of concern, three children had thymidine analogue mutations, associated with cross-resistance to all nucleoside reverse transcriptase inhibitors. Despite widespread resistance, however, only one child experienced a new WHO stage 4 event and none had a CD4 cell count of <200 cells/mm³.

Conclusions

Among children on long-term ART in rural Tanzania, >50% harboured drug resistance. Results for children were markedly poorer than for adults attending the same programme, underscoring the need for improved treatment strategies for children in resource-limited settings.

Generic and low dose antiretroviral therapy in adults and children: implication for scaling up treatment in resource limited settings

Although access to antiretroviral therapy (ART) for the treatment of HIV has increased during the last decade, many patients are still in need of treatment. With limited funds to provide ART to millions of patients worldwide, there is a need for alternative ways to scale up ART in resource limited settings. This review provides an overview of pharmacokinetic, safety and efficacy studies of generic and reduced dose ART. The production of generic ART has greatly influenced the decline in drug prices and the increased in ART access. Generic ART has good pharmacokinetic profile, safety and efficacy. Toxicity is however the main cause for ART discontinuation. Several dose reduction studies have shown adequate pharmacokinetic parameters and short term efficacy with reduced dose ART. Ethnicity may affect drug metabolism; several pharmacokinetic studies have confirmed higher plasma ART concentration in Asians. Randomized efficacy trial of reduced versus standard ART is warranted.

Pediatric adherence to HIV antiretroviral therapy

More than 2 million children are infected with HIV globally. Pediatric antiretroviral therapy (ART) adherence is complex, and current levels are often suboptimal. As established treatment programs in developed settings struggle with chronic therapy and nascent treatment programs in resource-limited settings expand, the importance and challenges of good adherence to ART are becoming ever more clear. Adherence behavior is influenced by many factors, which may be categorized as characteristics of the child, the caregiver(s) and family, the regimen, and society and culture. Many of these influences complicate measurement of pediatric adherence, and there is no gold standard. This article provides a conceptual framework and evidence-based look at the factors influencing ART adherence in children and aims to identify areas for intervention for this vulnerable population in need.