Accumulation of HIV-1 drug resistance after continued virological failure on first-line ART in adults and children in sub-Saharan Africa

Pretreatment and Acquired Drug Resistance in Children With Human Immunodeficiency Virus Type 1 in Jos, Nigeria

We determined pretreatment and acquired human immunodeficiency virus (HIV) drug resistance among children with HIV type 1 (HIV-1) in Jos, Nigeria. The majority (71%) of those who failed first-line antiretroviral therapy were on a nevirapine-containing regimen. The prevalence of pretreatment (48%) and acquired (76%) HIV drug resistance mutations was high in our study. Wider access to HIV drug resistance testing after treatment failure is necessary to optimize second-line treatment options among children with HIV in Nigeria.

Predictors of Treatment Adherence and Virological Failure Among People Living with HIV Receiving Antiretroviral Therapy in a South African Rural Community: A Sub-study of the ITREMA Randomised Clinical Trial

A large proportion of people living with HIV (PLHIV) in sub-Saharan Africa reside in rural areas. Knowledge of enablers and barriers of adherence to antiretroviral treatment (ART) in these populations is limited. We conducted a cohort study of 501 adult PLHIV on ART at a rural South African treatment facility as a sub-study of a clinical trial (ClinicalTrials.gov NCT03357588). Socio-economic, psychosocial and behavioral characteristics were assessed as covariates of self-reported adherence difficulties, suboptimal pill count adherence and virological failure during 96 weeks of follow-up. Male gender was an independent risk factor for all outcomes. Food insecurity was associated with virological failure in males. Depressive symptoms were independently associated with virological failure in both males and females. Household income and task-oriented coping score were protective against suboptimal pill-count adherence. These results underscore the impact of low household income, food insecurity and depression on outcomes of ART in rural settings and confirm other previously described risk factors. Recognition of these factors and targeted adherence support strategies may improve patient health and treatment outcomes.

High viral suppression and detection of dolutegravir-resistance associated mutations in treatment-experienced Tanzanian adults living with HIV-1 in Dar es Salaam

To curb HIV infection rate in Tanzania, antiretroviral therapy (ART) has been scaled up since 2006, and in 2019, the country shifted to regimen including dolutegravir as a default first line. We assessed the success of ART and the contribution of HIV drug resistance (HIVDR) to unsuppressed viral loads. Between February and May 2023 a cross-sectional survey with random sampling was conducted in the six clinics in an urban cohort in Dar es Salaam. Patients with unsuppresed viral loads (local criteria viral load (VL) ≥ 1000 copies/mL) were tested for HIVDR mutations using the WHO adapted protocol for plasma samples. Mutations were interpreted using the Stanford HIVDR database. In total 600 individuals participated in this survey, the majority were female (76.83%), mean age ([Formula: see text] standard deviation) was 44.0 ([Formula: see text] 11.6) years. The median duration on ART (interquartile range) was 6.5 (3.9-10.2) years. Approximately 99% were receiving tenofovir + lamivudine + dolutegravir as a fixed dose combination. VL testing was successful in 99.67% (598/600) of survey patients and only 33 had VL ≥ 1000 copies/mL, resulting in a viral suppression level of 94.48% (565/598, 95% CI 92.34-96.17%). For 23 samples, protease and reverse transcriptase (RT) genotyping were successful, with 13 sequences containing RT inhibitor surveillance drug resistance mutations (SDRMs) (56.5%). No SDRM against protease inhibitors were detected. Thirty samples were successfully genotyped for integrase with 3 sequences (10.08%) containing integrase strand transfer inhibitor (INSTI) SDRMs. In samples successfully genotyped in the three genetic regions, 68.18% (16/22) had a genotypic susceptibility score (GSS) ≥ 2.5 for the concurrent regimen, implying factors beyond drug resistance caused the unsuppressed viral load. For five patients, GSS indicated that HIVDR may have caused the unsuppressed viral load. All three patients with INSTI resistance mutations were highly resistant to dolutegravir and accumulated nucleoside and non-nucleoside RT inhibitor HIVDR mutations. Although in this cohort the last 95 UNAIDS target was almost achieved, HIVDR mutations, including INSTIs resistance mutations were detected in HIV-positive individuals taking ART for at least one year. We recommend the design and implementation of high-impact interventions to prevent the increase of HIVDR, failure of dolutegravir and address the non-resistance factors in the study area.

HIV Drug Resistance Patterns and Characteristics Associated with Clinically Significant Drug Resistance among Children with Virologic Failure on Antiretroviral Treatment in Kenya: Findings from the Opt4Kids Randomized Controlled Trial

Increasing HIV drug resistance (DR) among children with HIV (CHIV) on antiretroviral treatment (ART) is concerning. CHIV ages 1-14 years enrolled from March 2019 to December 2020 from five facilities in Kisumu County, Kenya, were included. Children were randomized 1:1 to control (standard-of-care) or intervention (point-of-care viral load (POC VL) testing every three months with targeted genotypic drug resistance testing (DRT) for virologic failure (VF) (≥1000 copies/mL)). A multidisciplinary committee reviewed CHIV with DRT results and offered treatment recommendations. We describe DR mutations and present logistic regression models to identify factors associated with clinically significant DR. We enrolled 704 children in the study; the median age was 9 years (interquartile range (IQR) 7, 12), 344 (49%) were female, and the median time on ART was 5 years (IQR 3, 8). During the study period, 106 (15%) children had DRT results (84 intervention and 22 control). DRT detected mutations associated with DR in all participants tested, with 93 (88%) having major mutations, including 51 (54%) with dual-class resistance. A history of VF in the prior 2 years (adjusted odds ratio (aOR) 11.1; 95% confidence interval (CI) 6.3, 20.0) and less than 2 years on ART at enrollment (aOR 2.2; 95% CI 1.1, 4.4) were associated with increased odds of major DR. DR is highly prevalent among CHIV on ART with VF in Kenya. Factors associated with drug resistance may be used to determine which children should be prioritized for DRT.

Clinical and Immunological Profiles of HIV/AIDS Patients With First-Line Antiretroviral Treatment Failure Attending a Tertiary Care Hospital

Objectives Highly active antiretroviral therapy (HAART) has decreased morbidity and mortality among HIV/AIDS-infected patients; however, many patients experience treatment failure. The present study aims to evaluate HIV-infected patients' clinical and immunological profiles with first-line antiretroviral treatment (ART) failure (immunological and clinical) at tertiary care hospitals in Northeast India and explore related treatment failure factors. Methods The hospital-based observational study was conducted among HIV-infected patients with first-line ART failure attending a tertiary care hospital from July 1, 2019, to June 30, 2020. The type of first-line ART failure was defined as a clinical, immunological, or virological failure as decided by the State AIDS Clinical Expert Panel (SACEP) meeting. Data were analyzed with Windows MS Excel (Microsoft Corporation, Redmond, Washington) and Statistical Package for the Social Sciences (SPSS) version 21 (IBM Corp., Armonk, NY). Results Among the 90 HIV-infected patients experiencing first-line ART treatment failure, the majority, 38 (42.2%), were in the age group of 30-40 years, 64 (71.1%) were males, and 70 (77.8%) were of average weight. Tuberculosis was the most typical opportunistic infection, affecting 11 (12.2%) patients. Most patients (38.9%) were initially presented at clinical stage 3. Maximum failures were experienced by patients with baseline CD4 ranging from 100-200 cells/mm3, with 38 (42.2%) patients, and by patients on efavirenz (64.5%) and tenofovir-based regimens (56.6%). Failures occurred more for 24-30 months and were common among patients with adherence below 90%. Conclusion Treatment failure was more common among young male patients and those with normal body mass index (BMI). Low baseline CD4 count and poor adherence were influential in the occurrence of treatment failure. First-line ART failure was higher in tenofovir- and efavirenz-based regimens.

Added Value of Next Generation Sequencing in Characterizing the Evolution of HIV-1 Drug Resistance in Kenyan Youth

Drug resistance remains a global challenge in children and adolescents living with HIV (CALWH). Characterizing resistance evolution, specifically using next generation sequencing (NGS) can potentially inform care, but remains understudied, particularly in antiretroviral therapy (ART)-experienced CALWH in resource-limited settings. We conducted reverse-transcriptase NGS and investigated short-and long-term resistance evolution and its predicted impact in a well-characterized cohort of Kenyan CALWH failing 1st-line ART and followed for up to ~8 years. Drug resistance mutation (DRM) evolution types were determined by NGS frequency changes over time, defined as evolving (up-trending and crossing the 20% NGS threshold), reverting (down-trending and crossing the 20% threshold) or other. Exploratory analyses assessed potential impacts of minority resistance variants on evolution. Evolution was detected in 93% of 42 participants, including 91% of 22 with short-term follow-up, 100% of 7 with long-term follow-up without regimen change, and 95% of 19 with long-term follow-up with regimen change. Evolving DRMs were identified in 60% and minority resistance variants evolved in 17%, with exploratory analysis suggesting greater rate of evolution of minority resistance variants under drug selection pressure and higher predicted drug resistance scores in the presence of minority DRMs. Despite high-level pre-existing resistance, NGS-based longitudinal follow-up of this small but unique cohort of Kenyan CALWH demonstrated continued DRM evolution, at times including low-level DRMs detected only by NGS, with predicted impact on care. NGS can inform better understanding of DRM evolution and dynamics and possibly improve care. The clinical significance of these findings should be further evaluated.

HIV virologic response, patterns of drug resistance mutations and correlates among adolescents and young adults: A cross-sectional study in Tanzania

BACKGROUND

The emergence of HIV drug resistance mutations (DRMs) is of significant threat to achieving viral suppression (VS) in the quest to achieve global elimination targets. We hereby report virologic outcomes and patterns of acquired DRMs and its associated factors among adolescents and young adults (AYA) from a broader HIV drug resistance surveillance conducted in Tanzania.

METHODS

Data of AYA was extracted from a cross-sectional study conducted in 36 selected facilities using a two-stage cluster sampling design. Dried blood spot (DBS) samples were collected and samples with a viral load (VL) ≥1000 copies/mL underwent genotyping for the HIV-1 pol gene. Stanford HIV database algorithm predicted acquired DRMs, Fisher's exact test and multivariable logistic regression assessed factors associated with DRMs and VS, respectively.

FINDINGS

We analyzed data of 578 AYA on antiretroviral therapy (ART) for 9-15 and ≥ 36 months; among them, 91.5% and 88.2% had VS (VL<1000copies/mL) at early and late time points, respectively. Genotyping of 64 participants (11.2%) who had VL ≥1000 copies/ml detected 71.9% of any DRM. Clinically relevant DRMs were K103N, M184V, M41L, T215Y/F, L210W/L, K70R, D67N, L89V/T, G118R, E138K, T66A, T97A and unexpectedly absent K65R. Participants on a protease inhibitor (PI) based regimen were twice as likely to not achieve VS compared to those on integrase strand transfer inhibitors (INSTI). The initial VL done 6 months after ART initiation of ≥1000copies/mL was the primary factor associated with detecting DRMs (p = .019).

CONCLUSIONS

VS amongst AYA is lower than the third UNAIDs target. Additionally, a high prevalence of ADR and high levels of circulating clinically relevant DRMs may compromise the long-term VS in AYA. Furthermore, the first VL result of ≥1000copies/ml after ART initiation is a significant risk factor for developing DRMs. Thus, strict VL monitoring for early identification of treatment failure and genotypic testing during any ART switch is recommended to improve treatment outcomes for AYA.

Prevalence of HIV drug resistance in Nigeria: results from a cross-sectional, population-based survey of Nigerian adults with unsuppressed viral load

BACKGROUND

HIV drug resistance (HIVDR) surveillance is an important tool to monitor threats to progress towards epidemic control. The characterization of HIVDR in Nigeria at the national level is needed to inform both clinical decisions and population-level HIV policy strategies. This study uses data obtained from the Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS) to describe the prevalence and distribution of HIVDR in Nigeria.

METHODS

NAIIS was a cross-sectional, population-based survey of households throughout Nigeria in 2018. NAIIS was designed to provide estimates of HIV prevalence and related health indicators from a nationally representative sample. The study population included participants aged 15-64 years who tested positive for HIV, had a viral load at least 1000 copies/ml, and had available HIV drug resistance genotypes. HIV isolates were genotyped to detect drug resistance mutations. Individual characteristics of study participants associated with HIVDR were identified using a weighted multivariable logistic regression model.

RESULTS

Of 1355 respondents with available HIV genotypes, 293 (19%) had evidence of drug-resistant mutations (DRMs) that conferred resistance to at least one antiretroviral drug. The majority of DRMs observed conferred resistance to NNRTIs (17.6%) and NRTIs (11.2%). HIVDR was associated with being ART-experienced, longer duration on ART, and lower CD4+ count but not sociodemographic characteristics.

CONCLUSION

The population level DRM prevalence in Nigeria was consistent with what would be expected in a mature HIV treatment landscape. The continued roll out of dolutegravir-anchored regimens should mitigate the impact of NNRTI resistance on population viral load suppression and progress towards epidemic control.

Prevalence of drug resistant HIV-1 forms in patients without any history of antiretroviral therapy in the Republic of Guinea

To study the structure of human immunodeficiency virus (HIV)-1 drug resistance (DR) in patients with newly diagnosed infection. Residents of the Republic of Guinea (N = 2168) were tested for HIV using enzyme-linked immunosorbent assay (ELISA). Individuals with a positive result were further examined for the presence of viral load in blood plasma. HIV was analyzed using Sanger sequencing. The obtained sequences were genotyped using REGA (version 3.0) and analyzed in MEGA 7. Analysis for the presence of DR mutations was performed using the Stanford University HIV DR Database. Serological markers of HIV were detected in 239 people, which represents 11.02% of the entire sample. HIV RNA was detected in 58 people. The following subtypes were seen: HIV CRF02_AG (41.9%); A1 (29.1%); A3 (12.9%); URF A1_G (12.9%); and G (3.2%). In 25% of patients, at least one significant mutation was encountered leading directly to HIV DR. The mutations encountered cause resistance to NRTI and NNRTI; one case of multiple resistance was identified. Major resistance to protease inhibitor was not seen. The detection of HIV-1 mutations associated with DR, in individuals who have never received antiretroviral therapy, is a cause for concern. It suggests that: new infections are occurring with strains that already have resistance; and the expansion of resistance is not always directly associated with selective drug pressure. Among the likely reasons for the high prevalence of primary HIV DR in the Republic of Guinea, drug availability is probably the key. The consequence of this is the lack of adherence of patients to treatment, the formation and transmission of resistant variants of the virus in the population. These findings suggest the need to test patients for resistant virus variants before initiating treatment.

Rate of virological failure and HIV-1 drug resistance among HIV-infected adolescents in routine follow-up on health facilities in Cameroon

The objective of this study was to determine the rates of virological failure (VF) and HIV drug resistance (HIVDR) amongst adolescents on antiretroviral Therapy (ART). A retrospectively designed study was conducted in 10 healthcare centers for adolescents living with HIV (ALHIV) in the two main cities of Cameroon (Yaoundé and Douala), from November 2018 to May 2019. Sociodemographic, clinical, therapeutic and laboratory parameters were collected from medical records. All enrolled ALHIV had viral load (VL) measurements following the national guidelines. All patients with a VL ≥ 1000 copies/ml were called to perform genotyping tests. The chi-square test was used to determine the factors associated with VF. Out of the 1316 medical records of ALHIV, we included 1083 ALHIV having a VL result. Among them, 276 (25.5%) were experiencing VF, and VF was significantly higher in ALHIV with suboptimal adherence (p<0.001), older adolescents (p<0.05), those who lived outside the city where they were receiving ART (p<0.006), severely immunocompromised (p<0.01) and started ART at infancy (p<0.02). Among the 45/276 (16.3%) participants with an available genotyping resistance testing (GRT) result, the overall rate of HIVDR was 93.3% (42/45). The most common mutations were K103N (n = 21/42, 52.3%) resulting in high-level resistance to Efavirenz and Nevirapine, followed by M184V (n = 20/42, 47.6%) and thymidine analog mutations (n = 15/42, 35.7%) associated with high-level resistance to Lamivudine and Zidovudine respectively. The high rate of VF and HIVDR among ALHIV regularly followed in health facilities in Cameroon highlights the need to develop interventions adapted to an adolescent-centered approach to preserve future ART options.

Minimal Cross-resistance to Tenofovir in Children and Adolescents Failing ART Makes Them Eligible for Tenofovir-Lamivudine-Dolutegravir Treatment

BACKGROUND

Fixed-dose combination of dolutegravir (DTG) with tenofovir disoproxil fumarate (TDF) and lamivudine (3TC) likely improves adherence and has a favorable resistance profile. We evaluated predicted efficacy of TLD (TDF-3TC-DTG) in children and adolescents failing abacavir (ABC), zidovudine (AZT), or TDF containing regimens.

METHODS

Drug resistance mutations were analyzed in a retrospective dataset of individuals <19 years of age, failing ABC (n = 293) AZT (n = 288) or TDF (n = 69) based treatment. Pol sequences were submitted to Stanford HIVdb v8.9. Genotypic susceptibility scores were calculated for various DTG-containing regimens.

RESULTS

Genotypes were assessed for 650 individuals with a median age of 14 years (IQR 10-17 years). More individuals failed a protease inhibitor (PI)-based (78.3%) than a non-nucleoside reverse transcriptase inhibitors (NNRTI)-based (21.7%) regimen. Most individuals in the AZT group (n = 288; 94.4%) failed a PI-based regimen, compared with 71.0% and 64.2% in the TDF (n = 69) and ABC group (n = 293). Genotypic sensitivity scores <2 to TLD were observed in 8.5% and 9.4% of ABC- and AZT-exposed individuals, compared with 23.2% in the TDF group. The M184V mutation was most often detected in the ABC group (70.6%) versus 60.0% and 52.4% in TDF and AZT groups. The presence of K65R was rare (n = 13, 2.0%) and reduced TLD susceptibility was commonly caused by accumulation of nucleoside reverse transcriptase inhibitor (NRTI) mutations.

CONCLUSIONS

Cross-resistance to TDF was limited, further reducing concerns about use of transition to TLD in children and adolescents. The NADIA trial has subsequently shown that patients failing a TDF/3TC/EFV regimen can safely be transitioned to a TLD regimen but we do not have data for patients failing an ABC/3TC/NNRTI or PI regimens. Frequent virological monitoring is recommended after switch to DTG, especially in children continuing ABC in the backbone. Clinical studies correlating predicted resistance with clinical outcomes, especially in settings without access to genotyping, are required.

Magnitude and predictors of HIV-Drug resistance in Africa: A protocol for systematic review and meta-analysis

Introduction

Human Immunodeficiency Virus (HIV) is continued to be a major public health problem in low-income countries and more importantly in Africa. For the last decade, access to Antiretroviral Therapy (ART) and its impact in improving quality of life and reducing HIV-related morbidity and mortality has significantly been improved in Africa. Nevertheless, the emergency of HIV drug resistance (HIVDR) has posed challenges in achieving optimal ART treatment outcomes and is alarmingly increasing globally in general and in Africa in particular. Comprehensive epidemiological data on the magnitude of HIVDR and HIVDR mutations, and predictors of HIVDR are, however, limited in Africa.

Objective

The main objective of this systematic review will be to estimate the pooled proportion of HIVDR and HIVDR mutations, and identify factors associated with HIVDR among people living with HIV/AIDS (PLWH) in Africa.

Method

Published Literature from 2000 until 30 October 2021 will be searched in PubMed/Medline Ovid, HINARI, SCOPUS, EMBASE, CINAHL, Web of Sciences, and Cochrane electronic databases. Initially, the literature will be screened based on title/abstract and followed by full-text appraisal for methodological quality using JBI critical appraisal tools. Data will be extracted from eligible articles after the full-text appraisal. Heterogeneity will be qualitatively assessed by a visual Funnel plot and quantitatively measured by an index of heterogeneity (I² statistics). Random-effects model will be fitted to estimate the proportion of HIVDR and each HIVDR mutations. Sub-group and sensitivity analyses will be conducted to reduce heterogeneity. Meta-regression will be done by median year of sampling per study to observe the pattern of changes over time. Publication bias will be assessed by egger’s statistics. In case of publication bias, Trim and Fill analysis will be conducted to overcome small-study effect. Data analysis will be performed using Stata version 14.

Ethics and dissemination

As the data sources are published papers, the protocol will not require an ethical approval letter. The final report of the review will be published in a peer-reviewed journal.

Drug resistance profiles and influencing factors among HIV-infected children and adolescents receiving long-term ART: a multicentre observational study in China

OBJECTIVES

To analyse the characteristics and determinants of drug resistance mutations (DRMs) in HIV-infected children and adolescents on long-term ART in China.

METHODS

An observational cohort study was conducted in five centres. All participants younger than 15 years at ART initiation were screened, and those identified as having virological failure (VF) with viral load (VL) ≥ 400 copies/mL were included for genotypic resistance testing. Logistic regression analysis was performed and the accumulation of major mutations was analysed in a subgroup of resistant individuals with complete VL results since HIV diagnosis.

RESULTS

Among 562 eligible participants, protease and RT regions were successfully amplified for 93 who failed treatment with a median of 10.0 years ART. Sixty-eight (73.1%) harboured ≥1 major mutations. NRTI, NNRTI and dual-class resistance accounted for 48.4%, 63.4% and 38.7%, respectively. Only 3.2% were resistant to PIs. Age at ART initiation [adjusted OR (aOR) = 0.813, 95% CI 0.690-0.957], subtype B (aOR = 4.378, 95% CI 1.414-13.560) and an initial NNRTI-based regimen (aOR = 3.331, 95% CI 1.180-9.402) were independently associated with DRMs. Among 40 resistant participants with additional VL data, 55.0% had continued VF on a suboptimal regimen and the estimated duration of VF was positively correlated with the total number of major mutations (r = 0.504, P = 0.001).

CONCLUSIONS

The development of DRMs was common in children and adolescents receiving long-term treatment, and continued VF was prevalent in those with resistance. Timely genotypic testing and new child-friendly formulations are therefore urgently required.

Archiving of mutations in HIV-1 cellular reservoirs among vertically infected adolescents is contingent with clinical stages and plasma viral load: Evidence from the EDCTP-READY study

INTRODUCTION

Globally, HIV-related adolescent deaths have increased about 50%, especially for those who are vertically infected. This could be driven by archived drug resistance mutations (DRMs) as children grow up, which might jeopardize antiretroviral therapy (ART). Our objective was to compare HIV-1 genotypic variation between plasma RNA and proviral DNA of vertically infected adolescents (aged 10-19 years) failing ART.

METHODS

A comparative study was conducted in 2019 among 296 adolescents with perinatal HIV infection (ALPHI) failing ART in health facilities of the Centre Region of Cameroon. The WHO clinical stage, CD4 count and plasma viral load (PVL) were measured. For those failing ART (PVL ≥ 1000 copies/mL), RNA (plasma) and proviral DNA (buffy coat) were sequenced in the pol gene at Chantal BIYA International Reference Centre (CIRCB), Yaoundé, Cameroon. HIV-1 subtypes and DRMs were interpreted using Stanford HIVdb v.8.8 and MEGA-X.

RESULTS

Of the 30% (89/296) failing ART, 81 had both RNA and DNA sequences generated and three were excluded for APOBEC mutations: the mean age was 16 ± 3 years; female-to-male ratio was 3:5; median PVL was 46 856 copies/mL [interquartile range (IQR): 19 898-271 410]; median CD4 count was 264 cells/μL (IQR: 131-574); and 42% were at WHO clinical stage 3/4. Subtype concordance between RNA and DNA viral strains was 100%, with CRF02_AG being predominant (65%) and two potential new recombinants found (A1/G/K; F1/G). Adolescents with DRMs were significantly higher in plasma than in proviral DNA (92% vs. 86%, p < 0.0001). Prevalent DRMs by drug class (RNA vs. DNA respectively) were at position M184 (74% vs. 67%) for nucleoside reverse transcriptase inhibitors (NRTIs), K103 (63% vs. 59%) for non-NRTIs, and V82, L76 and M46 (2% vs. 2%) for protease inhibitors. A total of 35% (27/78) of adolescents had concordant DRM profiles in RNA and DNA, while 27% (21/78) had DRMs only in proviral DNA. The presence of archived DRMs was associated with advanced clinical stage 3/4 (OR = 0.14, p = 0.0003) and PVL < 5 Log (Copies/mL) (OR: 4.88, p = 0.006).

CONCLUSIONS

Although plasma RNA remains more sensitive for detecting HIV-1 DRMs, about a quarter of ALPHI experiencing ART failure in an African setting might have archived DRMs in viral reservoirs, indicating clinically occult resistance. Thus, to ensure effective ART success, proviral DNA profiling (alongside RNA genotyping) would provide additional DRMs for adolescents with advanced clinical stages and/or moderate PVL.

Participants Switching to Second-Line Antiretroviral Therapy with Susceptible Virus Display Inferior Adherence and Worse Outcomes: An Observational Analysis

Evidence on the impact of human immunodeficiency virus (HIV) drug resistance on regimens following treatment failure is varied and inconclusive. Differential medication adherence may explain this variation. We aimed to test the association between drug resistance at first-line antiretroviral therapy (ART) switch and adherence to and virologic failure on subsequent ART. We conducted a secondary analysis of data from an open-labeled randomized trial of second-line ART (ACTG A5234). ART susceptibility was determined from study entry plasma using the Stanford Drug Resistance database version 8.7. Adherence was measured with microelectronic monitors. Three adherence variables and rates of virologic failure (HIV-1 RNA ≥1000 copies/mL) on second-line ART were compared between participants with and without resistance at first-line ART failure. Of 214 participants switching to second-line ART with baseline resistance results, 113 (53%) were men, mean age was 39 years (standard deviation 10.3), and 37 (17%) had susceptible virus at study entry. Cumulative genotypic susceptibility score (cGSS) was inversely associated with adherence, adjusted odds ratio (aOR) 0.15, 95% confidence interval (CI) (0.05-0.40), p < 0.001. The aOR of virologic failure for a one-unit increase in cGSS was 1.72, 95% CI (1.22-2.41), p < 0.001. Participants switched to second-line ART without resistance displayed inferior adherence and had higher rates of virologic failure. Therefore, these individuals warrant additional adherence interventions to help them achieve virologic success. Clinical Trial Registration number: NCT00608569.

Drug Resistance in HIV-Positive Adults During the Initial Year of Antiretroviral Treatment at Ethiopian Health Centers

Background

The increasing prevalence of antiretroviral drug resistance in Sub-Saharan Africa threatens the success of HIV programs. We have characterized patterns of drug resistance mutations (DRMs) during the initial year of antiretroviral treatment (ART) in HIV-positive adults receiving care at Ethiopian health centers and investigated the impact of tuberculosis on DRM acquisition.

Methods

Participants were identified from a cohort of ART-naïve individuals aged ≥18 years, all of whom had been investigated for active tuberculosis at inclusion. Individuals with viral load (VL) data at 6 and/or 12 months after ART initiation were selected for this study. Genotypic testing was performed on samples with VLs ≥500 copies/mL obtained on these occasions and on pre-ART samples from those with detectable DRMs during ART. Logistic regression analysis was used to investigate the association between DRM acquisition and tuberculosis.

Results

Among 621 included individuals (110 [17.5%] with concomitant tuberculosis), 101/621 (16.3%) had a VL ≥500 copies/mL at 6 and/or 12 months. DRMs were detected in 64/98 cases with successful genotyping (65.3%). DRMs were detected in 7/56 (12.5%) pre-ART samples from these individuals. High pre-ART VL and low mid-upper arm circumference were associated with increased risk of DRM acquisition, whereas no such association was found for concomitant tuberculosis.

Conclusions

Among adults receiving health center–based ART in Ethiopia, most patients without virological suppression during the first year of ART had detectable DRM. Acquisition of DRM during this period was the dominant cause of antiretroviral drug resistance in this setting. Tuberculosis did not increase the risk of DRM acquisition.

Who's slipping through the cracks? A comprehensive individual, clinical and health system characterization of people with virological failure on first-line HIV treatment in Uganda and South Africa

OBJECTIVES

HIV virological failure remains a major threat to programme success in sub-Saharan Africa. While HIV drug resistance (HIVDR) and inadequate adherence are the main drivers of virological failure, the individual, clinical and health system characteristics that lead to poor outcomes are not well understood. The objective of this paper is to identify those characteristics among people failing first-line antiretroviral therapy (ART).

METHODS

We enrolled a cohort of adults in HIV care experiencing virological failure on first-line ART at five sites and used standard statistical methods to characterize them with a focus on three domains: individual/demographic, clinical, and health system, and compared each by country of enrolment.

RESULTS

Of 840 participants, 51% were women, the median duration on ART was 3.2 years [interquartile range (IQR) 1.1, 6.4 years] and the median CD4 cell count prior to failure was 281 cells/µL (IQR 121, 457 cells/µL). More than half of participants [53%; 95% confidence interval (CI) 49-56%] stated that they had > 90% adherence and 75% (95% CI 72-77%) took their ART on time all or most of the time. Conversely, the vast majority (90%; 95% CI 86-92%) with a completed genotypic drug resistance test had any HIV drug resistance. This population had high health system use, reporting a median of 3 (IQR 2.6) health care visits and a median of 1 (IQR 1.1) hospitalization in the preceding 6 months.

CONCLUSIONS

Patients failing first-line ART in sub-Saharan Africa generally report high rates of adherence to ART, have extremely high rates of HIV drug resistance and utilize significant health care resources. Health systems interventions to promptly detect and manage treatment failure will be a prerequisite to establishing control of the HIV epidemic.

High rate of virological failure and HIV drug resistance in semi-rural Gabon and implications for dolutegravir-based regimen efficacy

BACKGROUND

The projected UNAIDS goal of ending AIDS by 2030 requires significant global efforts to improve current and future ART strategies. In this study, we assessed viral load (VL) suppression and acquired drug resistance, as well as future efficacy of dolutegravir-based combinations for patients living in semi-rural regions of Gabon.

METHODS

Eligible study participants were adults receiving ART and recruited between 2018 and 2019 in Franceville, Gabon. VL testing was conducted to assess VL suppression and HIV drug resistance (HIVDR) testing was performed to identify resistance mutations and assess their impact on ongoing and future ART regimens.

RESULTS

We recruited 219 participants overall. The median time on ART was 27 months and 216/219 participants were on first-line ART. VL suppression (VL < 1000 copies/mL) was 57.1% (95% CI 50.5-63.8) overall; 59.4% (51.4-67.5) and 52.2% (40.3-64.2) for women and men, respectively. The overall prevalence of HIVDR was 21.9% among the study population and 67.2% among those who failed ART. Presence of both NRTI and NNRTI mutations was found in 84.6% of sequences with drug resistance mutations, and full activity of a dolutegravir-based first-line regimen including tenofovir disoproxil fumarate/lamivudine/dolutegravir was expected only for 5/39 patients with a resistant virus.

CONCLUSIONS

This study shows a very low rate of VL suppression in a semi-rural context in Africa. Moreover, the high burden of HIVDR has affected both current and newly recommended ART strategies. Better management of ART in resource-limited settings is still a challenging ambition.

High level of HIV drug resistance informs dolutegravir roll-out and optimized NRTI backbone strategy in Mozambique

Background

HIV drug resistance (HIV-DR) is rising in sub-Saharan Africa in both ART-naive and ART-experienced patients.

Objectives

To estimate the level of acquired DR (ADR) and pre-treatment DR (PDR) across selected urban and rural sites in Southern Africa, in Mozambique.

Methods

We conducted two cross-sectional surveys among adult HIV patients (October 2017–18) assessing ADR and PDR. In the (ADR) survey, those on NNRTI-based first-line ART for ≥6 months were recruited (three sites). In the PDR survey, those ART-naive or experienced with ≥3 months of treatment interruption prior were enrolled (eight sites).

Results

Among 1113 ADR survey participants 83% were receiving tenofovir (TDF)/lamivudine (3TC)/efavirenz (EFV). The median time on ART was 4.5 years (Maputo) and 3.2 years (Tete), 8.3% (95% CI 6.2%-10.6%, Maputo) and 15.5% (Tete) had a VL ≥ 1000 copies/mL, among whom 66% and 76.4% had NNRTI+NRTI resistance, and 52.8% and 66.7% had 3TC+TDF-DR. Among those on TDF regimens, 31.1% (Maputo) and 42.2% (Tete) were still TDF susceptible, whereas 24.4% and 11.5% had TDF+zidovudine (ZDV)-DR. Among those on ZDV regimens, 25% and 54.5% had TDF+ZDV-DR. The PDR survey included 735 participants: NNRTI-PDR was 16.8% (12.0–22.6) (Maputo) and 31.2% (26.2–36.6) (Tete), with a higher proportion (≥50%) among those previously on ART affected by PDR.

Conclusions

In Mozambique, viral failure was driven by NNRTI and NRTI resistance, with NRTI DR affecting backbone options. NNRTI-PDR levels surpassed the WHO 10% ‘alert’ threshold. Replacing NNRTI first-line drugs is urgent, as is frequent viral load monitoring and resistance surveillance. Changing NRTI backbones when switching to second-line regimens may need reconsideration.

Predictors of Virologic Failure Among a Cohort of HIV-infected Children in Southern Ethiopia

BACKGROUND

Optimal care for children with HIV infection includes timely assessment of treatment failure. Using HIV viral load to define treatment failure remains a challenge in resource-limited settings.

METHODS

Children with HIV infection who were already on or starting first-line antiretroviral therapy were enrolled and followed over time. We examined clinical and immunologic predictors of virologic failure (VF), defined as consecutive viral load measurements > 1000 copies/mL (VF). Children were followed every 6 months with clinical assessments, immunologic assays and viral load testing until treatment failure or up to 18 months.

RESULTS

Of the 484 children with complete data, we observed a prevalence of 15% who had VF at enrollment, and 18 who developed VF over 10.5 person-years of follow-up for an incidence of 4.97 [95% CI: 3.04-7.70) per 100 person-years. Lower adherence, lower CD4 T-cell count, lower white blood cells count, lower platelets and a lower glomerular filtration rate were all associated with increased VF. However, in a multivariable analysis, renal function (estimated glomerular filtration rate < 90 mL/min), odds ratio: 11.5 (95% CI: 1.5-63.7), and lower adherence, odds ratio: 3.9 (95% CI: 1.1-13.4), were the only factors associated with development of VF.

CONCLUSIONS

We identified a significant risk of VF in children with HIV infection in a prospective cohort study in southern Ethiopia and limited predictive value of clinical variables for VF. This provides further evidence that rapid and reliable viral load testing is needed to adequately address the HIV epidemic, along with implementation of adherence interventions in sub-Saharan Africa.

Access to HIV Viral Load Testing and Antiretroviral Therapy Switch Practices: A Multicountry Prospective Cohort Study in Sub-Saharan Africa

Poor access to HIV viral load (VL) testing prevents the timely monitoring of HIV treatment adherence and efficacy. Factors enabling clinical benefits of VL testing when added to local standards of care, can inform the development of more cost-effective routine VL scale-up plans. We compared antiretroviral therapy (ART) switch practices in 13 clinics across 6 countries, with full (N = 8), phasing-in (N = 3) or no onsite access (N = 2) to VL. The analysis used data from the Pan-African Studies to Evaluate Resistance (PASER), observing virological and drug resistance outcomes among adults receiving first- or second-line ART between 2008 and 2015. Study plasma viral load (sVL) determined at baseline, every 12 months thereafter and at the time of switch served for retrospectively validating switch decisions, categorized into "necessary," "unnecessary," and "missed." Virological failure was defined as two consecutive sVL ≥1,000 HIV-RNA copies/mL. One thousand nine hundred ninety-five of the 2,420 (82.4%) study participants had continuous virological suppression during the median 30 months of follow-up. Among the 266 virological failures (11.0%), the proportion of necessary switches were similar in clinics with full (37%), phasing-in (25%), or no access (39%) to local VL testing. Documented utilization of local VL results for the switch decision was associated with higher percentage of necessary switch (87.6% vs. 67.9%). Shorter time to necessary switch was associated with higher rates of long-term virological suppression, regardless of access to local viral load. Availability of HIV VL testing capacity does not systematically result in adequate switch practices or better virological outcomes. Systems supporting sufficient test demand execution, and actual utilization of results for patient management need strengthening.

Patterns of acquired HIV-1 drug resistance mutations and predictors of virological failure in Moshi, Northern Tanzania

Emergence of HIV drug resistance poses a serious risk of inactivity to all currently approved antiretroviral drugs. Profiles of HIV drug resistance mutations (HIVDRM) and virological failure (VF) are not extensively studied in Tanzania. This study aimed to determine HIVDRM and predictors of VF in HIV-infected individuals failing first-line HIV drugs in Moshi, Northern Tanzania. A case-control study was conducted at Kilimanjaro Christian Medical Centre, Mawenzi, Pasua and Majengo health facilities with HIV-care and treatment clinics from October, 2017 to August, 2018. Cases and controls were HIV-infected individuals with VF and viral suppression (VS) respectively. HIV-1 reverse transcriptase and protease genes were amplified and sequenced. Stanford University's HIV drug resistance database and REGA subtyping tool 3.0 determined HIVDRM and HIV-1 subtypes respectively. Odds ratios (OR) with 95% confidence interval (95% CI) investigated predictors of VF. P-value < 5% was considered statistically significant. A total of 124 participants were recruited, of whom 63 (50.8%) had VF, 61 (49.2%) had VS and 82 (66.1%) were females. Median [IQR] age and duration on ART were 45 [35-52] years and 72 [48-104] months respectively. Twenty-five out of 26 selected samples from cases were successfully sequenced. Twenty-four samples (96%) had at least one major mutation conferring resistance to HIV drugs, with non-nucleoside analogue reverse transcriptase inhibitor (NNRTI)-resistance associated mutations as the majority (92%). Frequent NNRTI-resistance associated mutations were K103N (n = 11), V106M (n = 5) and G190A (n = 5). Prevalent nucleoside analogue reverse transcriptase inhibitors-resistance associated mutations were M184V (n = 17), K70R (n = 7) and D67N (n = 6). Dual-class resistance was observed in 16 (64%) samples. Thirteen samples (52%) had at least one thymidine analogue-resistance associated mutation (TAM). Three samples (12%) had T69D mutation with at least 1 TAM. Two samples (8%) had at least one mutation associated with protease inhibitor resistance. Age [aOR = 0.94, 95% CI (0.90-0.97), p < 0.001] and occupation [aOR = 0.35, 95% CI (0.12-1.04), p = 0.059] associated with VF. In conclusion, HIV drug resistance is common among people failing antiretroviral therapy. Resistance testing will help to guide switching of HIV drugs.

High Levels of Acquired HIV Drug Resistance Following Virological Nonsuppression in HIV-Infected Women from a High-Risk Cohort in Uganda

HIV drug resistance (HIVDR) is of increasing health concern, especially among key populations. We investigated the prevalence of virological suppression (VS), prevalence and correlates of HIVDR in HIV-infected women, enrolled in a high-risk cohort. We enrolled 267 women initiated on first-line antiretroviral therapy (ART) between 2015 and 2018. Participants' plasma samples were analyzed for HIV RNA viral load (VL) and genotypic resistance testing was performed on those with VL nonsuppression (defined as VL ≥1,000 copies/mL). We used the Stanford HIVDR database-algorithm to assess HIVDR mutations and logistic regression to assess risk factors for VL nonsuppression and HIVDR. We observed an overall VS prevalence of 76.0% (203/267) and detected respective acquired drug resistance prevalence to non-nucleoside reverse transcriptase inhibitors (NNRTIs) and nucleoside reverse transcriptase inhibitors (NRTIs) of 81.3% [confidence interval (CI) 67.4-91.1] and 45.8% (CI 31.4-60.8) among the 48 successfully genotyped VL nonsuppressors. NNRTI mutations were observed in 81.3% (39/48) of the genotyped participants and 45.8% (22/48) had both NRTI and NNRTI mutations. The mutation K103N was detected in 62.5% (30/48) of participants, 41.7% (20/48) had M184V/I, 14.6% had K65R, and 12.5% (6/48) had thymidine analog mutations (TAMs). None of the analyzed potential risk factors, including age and duration on ART, was significantly correlated with VL nonsuppression or HIVDR. Although high levels of NNRTI mutations support the transition to dolutegravir, the presence of NRTI mutations, especially TAMs, may compromise dolutegravir-based regimens or other second-line ART options. The moderate VS prevalence and high HIVDR prevalence therefore call for timely ART switching and intensive adherence counseling.

Human Immunodeficiency Virus-1 Viral Load Is Elevated in Individuals With Reverse-Transcriptase Mutation M184V/I During Virological Failure of First-Line Antiretroviral Therapy and Is Associated With Compensatory Mutation L74I

BACKGROUND

M184V/I cause high-level lamivudine (3TC) and emtricitabine (FTC) resistance and increased tenofovir disoproxil fumarate (TDF) susceptibility. Nonetheless, 3TC and FTC (collectively referred to as XTC) appear to retain modest activity against human immunodeficiency virus-1 with these mutations possibly as a result of reduced replication capacity. In this study, we determined how M184V/I impacts virus load (VL) in patients failing therapy on a TDF/XTC plus nonnucleoside reverse-transcriptase inhibitor (NNRTI)-containing regimen.

METHODS

We compared VL in the absence and presence of M184V/I across studies using random effects meta-analysis. The effect of mutations on virus reverse-transcriptase activity and infectiousness was analyzed in vitro.

RESULTS

M184I/V was present in 817 (56.5%) of 1445 individuals with virologic failure (VF). Virus load was similar in individuals with or without M184I/V (difference in log10 VL, 0.18; 95% confidence interval, .05-.31). CD4 count was lower both at initiation of antiretroviral therapy and at VF in participants who went on to develop M184V/I. L74I was present in 10.2% of persons with M184V/I but absent in persons without M184V/I (P < .0001). In vitro, L74I compensated for defective replication of M184V-mutated virus.

CONCLUSIONS

Virus loads were similar in persons with and without M184V/I during VF on a TDF/XTC/NNRTI-containing regimen. Therefore, we did not find evidence for a benefit of XTC in the context of first-line failure on this combination.

Long-term virological outcomes, failure and acquired resistance in a large cohort of Ugandan children

OBJECTIVES

To evaluate long-term virological failure (VF) and drug resistance among HIV-infected Ugandan children on first-line ART.

METHODS

In a multicentre prospective cohort study, viral load (VL) and drug resistance mutations (DRMs) were investigated at baseline and 6 monthly intervals in children (age ≤ 12 years). VF (two consecutive VLs >1000 copies/mL or death after 6 months of ART) was defined as early VF (0-24 months of ART) or late VF (25-48 months of ART). An active regimen was defined as partially active if the genotypic susceptibility score (GSS) was <3.

RESULTS

Between 2010 and 2011, 316 children were enrolled. Viral suppression was achieved in 75.8%, 71.5%, 72.6% and 69.2% at 12, 24, 36 and 48 months. VF occurred in 111/286 (38.8%), of which 67.6% was early and 32.4% late VF. Early VF was associated with a partially active regimen at baseline (OR 6.0, 95% CI 1.9-18.5), poor adherence (OR 3.1, 95% CI 1.3-7.4) and immunodeficiency (OR 3.3, 95% CI 1.1-10.2). Late VF was associated with age >3 years (OR 2.5, 95% CI 1.0-6.6) and WHO stage 3/4 (OR 4.2, 95% CI 1.4-13.4). Acquired DRMs were detected in 27.0% before 24 months, versus 14.4% after 24 months (P < 0.001). A total of 92.2% of the children with early VF, versus 56.2% with late VF, had a partially active regimen (P < 0.001).

CONCLUSIONS

VF rates were high, occurred predominantly in the first 24 months and appeared to increase again in year four. Risk factors and patterns of early VF/DRMs were different from those of late VF/DRMs. Virological control may improve by close monitoring and prompt switching to second-line therapy in the first 24 months. Late VF may be prevented by early start of ART.

High predictive efficacy of integrase strand transfer inhibitors in perinatally HIV-1-infected African children in therapeutic failure of first- and second-line antiretroviral drug regimens recommended by the WHO

Objectives

The predictive efficacy of integrase (IN) strand transfer inhibitors (INSTIs) was investigated in HIV-infected children born to HIV-infected mothers in Africa.

Methods

Plasma was collected at the Complexe Pédiatrique of Bangui, Central African Republic, from INSTI-naive children (n = 8) and adolescents (n = 10) in virological failure (viral load >1000 copies/mL) after 5 years of first- and/or second-line combination ART (cART). IN, reverse transcriptase (RT) and protease (P) genes were genotyped and drug resistance mutations (DRMs) to INSTIs, NRTIs, NNRTIs and PIs were interpreted using the Stanford algorithm.

Results

Successful IN, RT and P genotypes were obtained for 18, 13 and 15 children (median age 11 years, range 5–18; 8 were female), respectively. Two (2/18; 11.1%) viruses from children treated with a first-line regimen had INSTI DRMs at codon 138 (E138K and E138T), which is known to harbour major resistance mutations, and also had the accessory mutations L74I, G140K, G140R and G163R. The majority (16/18; 88.9%) of HIV-1 IN sequences demonstrated full susceptibility to all major INSTIs with a high frequency of natural polymorphic mutations. Most (12/15; 80%) genotyped viruses harboured at least one major DRM conferring resistance to at least one of the WHO-recommended antiretroviral drugs (NNRTIs, NRTIs and PIs) prescribed in first- and second-line regimens.

Conclusions

INSTIs could be proposed in first-line regimens in the majority of African children or adolescents and may constitute relevant therapeutic alternatives as second- and third-line cART regimens in HIV-infected children and adolescents living in sub-Saharan Africa.

The relative contributions of HIV drug resistance, nonadherence and low-level viremia to viremic episodes on antiretroviral therapy in sub-Saharan Africa

INTRODUCTION

To achieve viral suppression among more than 90% of people on antiretroviral therapy (ART), improved understanding is warranted of the modifiable causes of HIV viremic episodes. We assessed the relative contributions of drug-resistance, nonadherence and low-level viremia (LLV) (viral load 50-999 cps/ml) on viremic episodes in sub-Saharan Africa.

METHODS

In a multicountry adult cohort initiating nonnucleoside reverse transcriptase inhibitor-based first-line ART, viremic episodes (viral load ≥1000 cps/ml) were classified as first, viral nonsuppression at 12 months; second, virological rebound at 24 months (after initial viral suppression at 12 months); third, failure to achieve viral resuppression at 24 months (after viremic episode at 12 months). We used adjusted odds ratios from multivariable logistic regression to estimate attributable fractions for each risk factor.

RESULTS

Of 2737 cohort participants, 1935 had data on pretreatment drug resistance (PDR) and at least 1 viral load outcome. Viral nonsuppression episodes [173/1935 (8.9%)] were attributable to nonadherence in 30% (35% in men vs. 24% in women) and to PDR to nonnucleoside reverse transcriptase inhibitors in 10% (15% in women vs. 6% in men). Notably, at contemporary PDR prevalences of 10-25%, PDR would explain 13-30% of viral nonsuppression. Virological rebound episodes [96/1515 (6.3%)] were mostly attributable to LLV (29%) and nonadherence (14%), and only rarely to PDR (1.1%). Failures to achieve viral resuppression [66/81 (81.5%)] were mostly attributable to the presence of acquired drug resistance (34%) and only rarely to nonadherence (2.4%).

CONCLUSION

Effective adherence interventions could substantially reduce viral nonsuppression (especially in men) and virological rebound (especially during LLV), but would have limited effect on improving viral resuppression. Alternative ART regimens could circumvent PDR and acquired resistance.

Sub-attomole detection of HIV-1 using padlock probes and rolling circle amplification combined with microfluidic affinity chromatography

Despite significant progress in diagnostics and disease management during the past decades, human immunodeficiency virus (HIV) infections are still responsible for nearly 1 million deaths every year, mostly in resource-limited settings. Thus, novel, accurate and cost-effective tools for viral load monitoring become crucial to allow specific diagnostics and the effective monitoring of the associated antiviral therapies. Herein, we report an effective combination of a (1) padlock probe (PLP)-mediated rolling circle amplification (RCA) bioassay and an (2) agarose bead-based microfluidic device for the affinity chromatography-based capture and detection of RCA products (RCPs) pre-labelled simultaneously with biotin and an organic fluorophore. This method allowed the efficient capture of ~1 μm-sized RCPs followed by their quantification either as discrete signals or an average fluorescence signal, thus being compatible with both high-resolution imaging for maximum sensitivity as well as simpler optical detection setups. A limit of detection < 30 fM was obtained for HIV-1 synthetic target with just a single round of RCA, comparable to recently reported procedures requiring technically complex amplification strategies such as hyperbranching and/or enzymatic digestion/amplification. Furthermore, targeting a set of five conserved regions in the HIV-1 gag gene, the method could specifically detect HIV-1 in 293T cell culture supernatants, as well as a set of 11 HIV-1 NIH reference samples with four different subtypes. The reported method provides simplicity of operation, unique versatility of signal transduction (i.e. average or discrete signals), and potential coupling with previously reported miniaturized photodetectors. These combined features hold promise for bringing RCA-based molecular diagnostics closer to the point-of-care.

Prevalence of pretreatment and acquired HIV-1 mutations associated with resistance to lamivudine or rilpivirine: a systematic review

BACKGROUND

Pretreatment and acquired drug resistance mutations (DRMs) can limit antiretroviral therapy effectiveness.

METHODS

We review prevalence of DRMs with resistance to nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs), focusing on lamivudine and rilpivirine, from 127 articles with >100,000 individuals with HIV-1 infection.

RESULTS

Estimated global prevalence of pretreatment resistance to any NRTI was 4% and to any NNRTI was 6%. Most prevalent DRMs resistant to lamivudine or rilpivirine were at positions E138 (4%), V179 (1%) and M184 (1%). Estimated acquired DRM prevalence was 58% for any NRTIs and 67% for any NNRTIs, most frequently at positions M184 (58%) and Y181 (21%).

CONCLUSIONS

This review suggests low risk of lamivudine- or rilpivirine-resistant mutations in treatment-naive, HIV-1-infected individuals.

Drug Resistance Among Adolescents and Young Adults with Virologic Failure of First-Line Antiretroviral Therapy and Response to Second-Line Treatment

Barriers to sustainable virologic suppression (VS) of HIV-infected adolescents and young adults include drug resistance mutations (DRMs) and limited treatment options, which may impact the outcome of second-line antiretroviral therapy (ART). We sequenced plasma viral RNA from 74 adolescents and young adults (16-24 years) failing first-line ART at Newlands Clinic, Zimbabwe between October 2015 and December 2016. We evaluated first-line nucleoside reverse transcriptase inhibitor (NRTI) susceptibility scores to first- and second-line regimens. Boosted protease inhibitor (bPI)-based ART was provided and viral load (VL) monitored for ≥48 weeks. Fisher's exact test was used to evaluate factors associated with VS on second-line regimens, defined as VL <1,000 copies/mL (VS_1,000) or <50 copies/mL (VS₅₀). The 74 participants on first-line ART had a median [interquartile range (IQR)] age of 18 (16-21) years and 42 (57%) were female. The mean (±standard deviation) duration on ART was 5.5 (±3.06) years and the median (IQR) log₁₀ VL was 4.26 (3.78-4.83) copies/mL. After switching to a second-line PI regimen, 88% suppressed to <1,000 copies/mL and 76% to <50 copies/mL at ≥48 weeks. A new NRTI was associated with increased VS₅₀ (p = .031). These 74 adolescents and young adults failing first-line ART demonstrated high levels (97%) of DRMs, despite enhanced adherence counseling. Switching to new NRTIs in second-line improved VS. With the widespread adoption of generic dolutegravir, lamivudine and tenofovir combinations in Africa, genotyping to determine NRTI susceptibility, may be warranted.

Evolution of HIV-1 drug resistance after virological failure of first-line antiretroviral therapy in Lusaka, Zambia

BACKGROUND

HIV viral load (VL) and resistance testing are limited in sub-Saharan Africa, so individuals may have prolonged time on failing first-line antiretroviral therapy (ART). Our objective was to describe the evolution of drug resistance mutations among adults failing first-line ART in Zambia.

METHODS

We analysed data from a trial of VL monitoring in Lusaka, Zambia. From 2006 to 2011, 12 randomized sites provided either routine VL monitoring (intervention) or discretionary (control) after ART initiation. Samples were collected prospectively following the same schedule in each arm but analysed retrospectively in the control group. For those with virological failure (VF; >400 copies/ml), HIV genotyping was performed retrospectively on baseline (BL) and on all subsequent specimens until censored due to study completion, withdrawal or death.

RESULTS

Of 1,973 enrollees, 165 (8.4%) developed VF. 464 genotype results were available including 132 (80%) at BL, 116 (70%) at VF and 125 (76%) had at least one result between VF and censoring. Major nucleoside reverse transcriptase inhibitor (NRTI) or non-nucleoside reverse transcriptase inhibitor (NNRTI) mutations increased from 26% (BL) to 82% (VF) to 89% at last genotype (LG). M184 mutations increased from 2% to 59% to 71%; K65R from 2% to 11% to 13%; 2 or more thymidine analogue mutations from 1% to 3% to 12%. Among those on a failing tenofovir disoproxil fumarate (TDF)-based regimen, TDF resistance increased from 42% to 58%.

CONCLUSIONS

We found substantial resistance to NRTIs and NNRTIs at VF with incremental increases after VF while still on a failing first-line ART; this resistance may compromise attainment of the UNAIDS 90-90-90 goals.

Prevalence of pretreatment HIV drug resistance in West African and Southeast Asian countries

Background

ART in the developing world has moved to a new era with the WHO recommendation to test and immediately treat HIV-positive individuals. A high frequency of pretreatment HIV drug resistance (PDR) can compromise ART efficacy. Our study presents updated estimates of PDR in seven countries from West Africa (Burkina Faso, Cameroon, Côte d’Ivoire, Mali and Togo) and Southeast Asia (Thailand and Vietnam).

Methods

Eligible study participants were adult ART initiators, recruited from December 2015 to November 2016 in major ART clinics in each country. HIV drug resistance (HIVDR) tests were performed for all specimens and interpretation was done using the Stanford algorithm.

Results

Overall, 1153 participants were recruited and 1020 nt sequences were generated. PDR frequency among all initiators was 15.9% (95% CI: 13.8%–18.3%) overall, ranging from 9.6% and 10.2% in Burkina Faso and Thailand, respectively, 14.7% in Vietnam, 15.4% in Mali, 16.5% in Côte d’Ivoire and 19.3% in Cameroon, to 24.6% in Togo. The prevalence of NNRTI resistance mutations was 12%; NRTI and PI PDR prevalences were 4% and 3%, respectively.

Conclusions

Our study shows that in most countries PDR exceeded 10%, warranting the conduct of nationally representative surveys to confirm this trend. In the meantime, actions to prevent drug resistance, including transition from NNRTIs to more robust drug classes should be urgently implemented.

The role of drug resistance in poor viral suppression in rural South Africa: findings from a population-based study

BACKGROUND

Understanding factors driving virological failure, including the contribution of HIV drug resistance mutations (DRM), is critical to ensuring HIV treatment remains effective. We examine the contribution of drug resistance mutations for low viral suppression in HIV-positive participants in a population-based sero-prevalence survey in rural South Africa.

METHODS

We conducted HIV drug resistance genotyping and ART analyte testing on dried blood spots (DBS) from HIV-positive adults participating in a 2014 survey in North West Province. Among those with virologic failure (> 5000 copies/mL), we describe frequency of DRM to protease inhibitors (PI), nucleoside reverse transcriptase inhibitors (NRTI), and non-nucleoside reverse transcriptase inhibitors (NNRTI), report association of resistance with antiretroviral therapy (ART) status, and assess resistance to first and second line therapy. Analyses are weighted to account for sampling design.

RESULTS

Overall 170 DBS samples were assayed for viral load and ART analytes; 78.4% of men and 50.0% of women had evidence of virologic failure and were assessed for drug resistance, with successful sequencing of 76/107 samples. We found ≥1 DRM in 22% of participants; 47% were from samples with detectable analyte (efavirenz, nevirapine or lopinavir). Of those with DRM and detectable analyte, 60% showed high-level resistance and reduced predicted virologic response to ≥1 NRTI/NNRTI typically used in first and second-line regimens.

CONCLUSIONS

DRM and predicted reduced susceptibility to first and second-line regimens were common among adults with ART exposure in a rural South African population-based sample. Results underscore the importance of ongoing virologic monitoring, regimen optimization and adherence counseling to optimize durable virologic suppression.

Incidence and Predictors of Treatment Failure Among Children Receiving First-Line Antiretroviral Treatment in General Hospitals of Two Zones, Tigray, Ethiopia, 2019

Background

Despite many efforts undertaken to control the human immunodeficiency virus epidemic, it remains to be the major global public health challenge. With expanding access to pediatric antiretroviral therapy, children are more likely to experience treatment failure. All previous studies conducted in Ethiopia estimated treatment failure using only clinical and CD4 criteria. Thus, the ART failure rate is expected to be underestimated in our country.

Objectives of the Study

To assess the incidence and predictors of treatment failure among children receiving first-line ART in general hospitals of Mekelle and Southern Zones of Tigray region, Ethiopia, 2019.

Methods

Retrospective follow up study was employed. The sample size was estimated based on a Log rank test using Stata V-13 and all 404 charts were taken for review. Data were collected by extraction tool; entered using Epi-data manager; cleaned and analyzed by Stata V-14. Data were described using the Kaplan-Meier curve, Log rank test, life table, and crude hazard ratios and analyzed using adjusted hazard ratios and p-value by Cox proportional hazard regression. Any variable at P <0.05 in the bi–variable analysis was taken to multi–variate analysis and significance was declared at P≤ 0.05. Data were presented using tables, charts, and texts.

Results

The incidence rate of ART failure was 8.68 (95% CI 7.1 to 10.6) per 1000 person-month observations with a total of 11,061.5 person-month observations. Children who had tuberculosis at baseline [AHR=2.27; 95% CI 1.12–4.57], advanced recent WHO stage [AHR=5.21; 95% CI 2.75–9.88] and sub-optimal ART adherence [AHR=2.84, 95% CI 1.71–4.72] were at higher hazard for first-line treatment failure. Besides this having a long duration of ART follow up [AHR=0.85; 95% CI 0.82–0.87] was found to be protective against treatment failure.

Conclusion and Recommendation

The incidence of first-line ART failure was grown as a major public health concern. Treatment failure was predicted by the duration of follow up, advanced recent WHO stage, sub-optimal adherence, as well as the presence of tuberculosis at baseline. Hence, it is better to give priority for strengthening the focused evaluation of the WHO clinical stage and tuberculosis co-infection at baseline with continuous adherence monitoring.

Measuring retention in care for HIV-positive pregnant women in Prevention of Mother-to-Child Transmission of HIV (PMTCT) option B+ programs: the Mozambique experience

BACKGROUND

Failure to retain HIV-positive pregnant women on antiretroviral therapy (ART) leads to increased mortality for the mother and her child. This study evaluated different retention measures for women's engagement along the continuum of care for prevention of mother-to-child transmission (PMTCT) option B+ services in Mozambique.

METHODS

We compared 'point' retention (patient's presence in care 12-month post-ART initiation or any time thereafter) with the following definitions: alive and in care 12 month post-ART initiation (Ministry of Health; MOH); attendance at a health facility up to 15-month post-ART initiation (World Health Organization; WHO); alive and in treatment at 1-, 2-, 3-, 6-, 9-, and 12-month post-ART initiation (Inter-Agency Task Team; IATT); and alive and in care 12-month post-ART initiation with ≥75% appointment adherence during follow-up (i.e. 'appointment adherence' retention) or with ≥75% of appointments met on time during follow-up (i.e. 'on-time adherence' retention). Kaplan-Meier survival curves were produced to assess variability in retention rates. We used 'on-time adherence' retention as our reference to estimate sensitivity, specificity, and proportion of misclassified patients.

RESULTS

Considering the 'point' retention definition, 16,840 HIV-positive pregnant women enrolled in option B+ PMTCT services were identified as 'retained in care' 12-month post-ART initiation. Of these, 60.3% (95% CI 59.6-61.1), 84.8% (95% CI 84.2-85.3), and 16.4% (95% CI 15.8-17.0) were classified as 'retained in care' using MOH, WHO, and IATT definitions, respectively, and 1.2% (95% CI 1.0-1.4) were classified as 'retained in care' using the '≥75% on-time adherence' definition. All definitions provided specificity rates of ≥98%. The sensitivity rates were 3.0% with 78% of patients misclassified according to the WHO definition and 4.3% with 54% of patients misclassified according to the MOH definition. The 'point' retention definition misclassified 97.6% of patients. Using IATT and 'appointment adherence' retention definitions, sensitivity rates (9.0 and 11.7%, respectively) were also low; however, the proportion of misclassified patients was smaller (15.9 and 18.3%, respectively).

CONCLUSION

More stringent definitions indicated lower retention rates for PMTCT programs. Policy makers and program managers should include attendance at follow-up visits when measuring retention in care to better guide planning, scale-up, and monitoring of interventions.

Advances in Developing CAR T-Cell Therapy for HIV Cure

Acquired immune deficiency syndrome (AIDS), which is caused by HIV infection, is an epidemic disease that has killed millions of people in the last several decades. Although combination antiretroviral therapy (cART) has enabled tremendous progress in suppressing HIV replication, it fails to eliminate HIV latently infected cells, and infected individuals remain HIV positive for life. Lifelong antiretroviral therapy is required to maintain control of virus replication, which may result in significant problems, including long-term toxicity, high cost, and stigma. Therefore, novel therapeutic strategies are urgently needed to eliminate the viral reservoir in the host for HIV cure. In this review, we compare several potential strategies regarding HIV cure and focus on how we might utilize chimeric antigen receptor-modified T cells (CAR T) as a therapy to cure HIV infection.

High turnaround times and low viral resuppression rates after reinforced adherence counselling following a confirmed virological failure diagnostic algorithm in HIV-infected patients on first-line antiretroviral therapy from Tanzania

OBJECTIVE

Early identification of confirmed virological failure is paramount to avoid accumulation of drug resistance in patients on antiretroviral therapy (ART). Scale-up of HIV-RNA monitoring in Africa and timely switch to second-line regimens are challenged.

METHODS

A WHO adapted confirmed virological treatment screening algorithm (HIV-RNA screening, enhanced adherence counselling, confirmatory HIV-RNA testing) was evaluated in HIV-infected patients on first-line ART from Tanzania. The main endpoints included viral resuppression and virological failure rates, retention and turnaround time of the screening algorithm until second-line ART initiation. Secondary endpoints included risk factors for virological treatment failure and patterns of genotypic drug resistance.

RESULTS

HIV-RNA >1000 copies/ml at first screening was detected in 58/356 (16.3%) patients (median time-on-treatment 6.3 years, 25% immunological treatment failure). Adjusted risk factors for virological failure were age <30 years (RR 5.2 [95% CI: 2.5-10.8]), years on ART ≥3 years (RR 3.0 [1.0-8.9]), CD4-counts <200 cells/µl (RR 9.3 [4.0-21.8]) and poor self-reported treatment adherence (RR 2.0 [1.2-3.4]). Resuppression of HIV-RNA <1000 copies/ml was observed in 5/50 (10%) cases after enhanced adherence counselling. Confirmatory testing within 3 months was performed in only 46.6% and switch to second-line ART within 6 months in 60.4% of patients. Major NNRTI-mutation were detected in all of 30 patients, NRTI mutations in 96.7% and ≥3 thymidine-analogue mutations in 40%. No remaining NRTI options were predicted in 57% and limited susceptibility in 23% of patients.

CONCLUSION

We observed low levels of viral resuppression following adherence counselling, associated with high levels of accumulated drug resistance. High visit burden and turnaround times for confirmed virological failure diagnosis further delayed switching to second-line treatment which could be improved using novel point-of-care viral load monitoring systems.

The Impact of HIV-1 Drug Escape on the Global Treatment Landscape

The rising prevalence of HIV drug resistance (HIVDR) could threaten gains made in combating the HIV epidemic and compromise the 90-90-90 target proposed by United Nations Programme on HIV/AIDS (UNAIDS) to have achieved virological suppression in 90% of all persons receiving antiretroviral therapy (ART) by the year 2020. HIVDR has implications for the persistence of HIV, the selection of current and future ART drug regimens, and strategies of vaccine and cure development. Focusing on drug classes that are in clinical use, this Review critically summarizes what is known about the mechanisms the virus utilizes to escape drug control. Armed with this knowledge, strategies to limit the expansion of HIVDR are proposed.

Drug resistance outcomes of long-term ART with tenofovir disoproxil fumarate in the absence of virological monitoring

Objectives

The resistance profiles of patients receiving long-term ART in sub-Saharan Africa have been poorly described. This study obtained a sensitive assessment of the resistance patterns associated with long-term tenofovir-based ART in a programmatic setting where virological monitoring is yet to become part of routine care.

Methods

We studied subjects who, after a median of 4.2 years of ART, replaced zidovudine or stavudine with tenofovir disoproxil fumarate while continuing lamivudine and an NNRTI. Using deep sequencing, resistance-associated mutations (RAMs) were detected in stored samples collected at tenofovir introduction (T0) and after a median of 4.0 years (T1).

Results

At T0, 19/87 (21.8%) subjects showed a detectable viral load and 8/87 (9.2%) had one or more major NNRTI RAMs, whereas 82/87 (94.3%) retained full tenofovir susceptibility. At T1, 79/87 (90.8%) subjects remained on NNRTI-based ART, 5/87 (5.7%) had introduced lopinavir/ritonavir due to immunological failure, and 3/87 (3.4%) had interrupted ART. Whilst 68/87 (78.2%) subjects maintained or achieved virological suppression between T0 and T1, a detectable viral load with NNRTI RAMs at T0 predicted lack of virological suppression at T1. Each treatment interruption, usually reflecting unavailability of the dispensary, doubled the risk of T1 viraemia. Tenofovir, lamivudine and efavirenz selected for K65R, K70E/T, L74I/V and Y115F, alongside M184V and multiple NNRTI RAMs; this resistance profile was accompanied by high viral loads and low CD4 cell counts.

Conclusions

Viraemia on tenofovir, lamivudine and efavirenz led to complex resistance patterns with implications for continued drug activity and risk of onward transmission.

HIV-1 Drug Resistance Among Ugandan Adults Attending an Urban Out-Patient Clinic

BACKGROUND

Little is known about prevalence of drug resistance among HIV-infected Ugandans, a setting with over 15 years of public sector access to antiretroviral therapy (ART) and where virological monitoring was only recently introduced.

SETTING

This study was conducted in the adults' out-patient clinic of the Infectious Diseases Institute, Kampala, Uganda.

METHODS

HIV genotyping was performed in ART-naive patients and in treatment-experienced patients on ART for ≥6 months with virological failure (≥1000 copies/mL).

RESULTS

A total of 152 ART-naive and 2430 ART-experienced patients were included. Transmitted drug resistance was detected in 9 (5.9%) patients. After a median time on ART of 4.7 years [interquartile range: 2.5-8.7], 190 patients (7.8%) had virological failure with a median viral load of 4.4 log10 copies per milliliter (interquartile range: 3.9-4.9). In addition, 146 patients had a viral load between 51 and 999 copies per milliliter. Most patients with virological failure (142, 74.7%) were on first-line ART. For 163 (85.8%) ART-experienced patients, genotype results were available. Relevant drug-resistance mutations were observed in 135 (82.8%), of which 103 (63.2%) had resistance to 2 drug classes, and 11 (6.7%) had resistance to all drug classes available in Uganda.

CONCLUSION

The prevalence of transmitted drug resistance was lower than recently reported by the WHO. With 92% of all patients virologically suppressed on ART, the prevalence of virological failure was low when a cutoff of 1000 copies per milliliter is applied, and is in line with the third of the 90-90-90 UNAIDS targets. However, most failing patients had developed multiclass drug resistance.

Simplifying switch to second-line antiretroviral therapy in sub Saharan Africa: predicted effect of using a single viral load to define efavirenz-based first-line failure

Background:

Many individuals failing first-line antiretroviral therapy (ART) in sub-Saharan Africa never initiate second-line ART or do so after significant delay. For people on ART with a viral load more than 1000 copies/ml, the WHO recommends a second viral load measurement 3 months after the first viral load and enhanced adherence support. Switch to a second-line regimen is contingent upon a persistently elevated viral load more than 1000 copies/ml. Delayed second-line switch places patients at increased risk for opportunistic infections and mortality.

Methods:

To assess the potential benefits of a simplified second-line ART switch strategy, we use an individual-based model of HIV transmission, progression and the effect of ART which incorporates consideration of adherence and drug resistance, to compare predicted outcomes of two policies, defining first-line regimen failure for patients on efavirenz-based ART as either two consecutive viral load values more than 1000 copies/ml, with the second after an enhanced adherence intervention (implemented as per current WHO guidelines) or a single viral load value more than 1000 copies/ml. We simulated a range of setting-scenarios reflecting the breadth of the sub-Saharan African HIV epidemic, taking into account potential delays in defining failure and switch to second-line ART.

Findings:

The use of a single viral load more than 1000 copies/ml to define ART failure would lead to a higher proportion of persons with nonnucleoside reverse-transcriptase inhibitor resistance switched to second-line ART [65 vs. 48%; difference 17% (90% range 14–20%)], resulting in a median 18% reduction in the rate of AIDS-related death over setting scenarios (90% range 6–30%; from a median of 3.1 to 2.5 per 100 person-years) over 3 years. The simplified strategy also is predicted to reduce the rate of AIDS conditions by a median of 31% (90% range 8–49%) among people on first-line ART with a viral load more than 1000 copies/ml in the past 6 months. For a country of 10 million adults (and a median of 880 000 people with HIV), we estimate that this approach would lead to a median of 1322 (90% range 67–3513) AIDS deaths averted per year over 3 years. For South Africa this would represent around 10 215 deaths averted annually.

Interpretation:

As a step towards reducing unnecessary mortality associated with delayed second-line ART switch, defining failure of first-line efavirenz-based regimens as a single viral load more than 1000 copies/ml should be considered.

Drug resistance from preferred antiretroviral regimens for HIV infection in South Africa: A modeling study

BACKGROUND

Tenofovir-containing regimens comprise the preferred first-line antiretroviral therapy (ART) in many countries including South Africa, where utilization of second-line regimens is limited. Considerable HIV drug resistance has occurred among persons failing tenofovir-containing first-line ART. We evaluated drug resistance at the population level using mathematical modeling.

SETTING

Heterosexual HIV epidemic in KwaZulu-Natal, South Africa.

METHODS

We constructed a stochastic individual-based model and simulated scenarios of ART implementation, either CD4-based (threshold < 500 cells/mL) or Fast-track (81% coverage by 2020), with consideration of major drug-associated mutations (M184V, K65R and non-nucleoside reverse transcriptase inhibitor (NNRTI)). Using base case and uncertainty analyses, we assessed (majority) drug resistance levels.

RESULTS

By 2030, the median total resistance (proportion of HIV-infected persons with drug resistance) is predicted to reach 31.4% (interquartile range (IQR): 16.5%-50.2%) with CD4-based ART, decreasing to 14.5% (IQR: 7.7%-25.8%) with Fast-track implementation. In both scenarios, we find comparably high prevalence (~80%) of acquired NNRTI-associated, M184V and K65R mutations. Over 48% of individuals with acquired resistance harbor dual, 44% triple and 7% just single drug mutations. Drug-resistant HIV is predicted to comprise 40% (IQR: 27%-50%) of incident infections, while 70% of prevalent transmitted resistance is NNRTI-associated. At 2018, the projected total resistance is 15% (IQR: 7.5%-25%), with 18% (IQR: 13%-24%) of incident infections from transmitted drug-resistant HIV.

CONCLUSIONS

WHO-recommended preferred first-line ART could lead to substantial drug resistance. Effective surveillance of HIV drug resistance and utilization of second-line as well as alternative first-line regimens is crucial.

Pretreatment HIV drug resistance in low- and middle-income countries

Pretreatment HIV drug resistance (PDR) has been increasing with scale-up of antiretroviral therapy (ART) in low- and middle-income countries. Delay in responding to rising levels of PDR is projected to fuel a worldwide increase in mortality, HIV incidence and ART costs. Strategies to curb the rise in PDR include using antiretrovirals (ARVs) with high-genetic barrier to resistance in first-line therapy and for prophylaxis in HIV exposed infants, enhancing HIV drug resistance surveillance in populations initiating, receiving ART, and in those on pre-exposure prophylaxis, universal access and effective use of viral-load tests, improving adherence and retention and minimizing ART programmatic quality gaps. In this review, we assess the drivers of PDR, and potential strategies to mitigate its rise in prevalence and impact in low- and middle-income countries.

High Levels of HIV-1 Drug Resistance in Children Who Acquired HIV Infection Through Mother to Child Transmission in the Era of Option B+, Haiti, 2013 to 2014

BACKGROUND

The main objective of this study was to determine the frequency and patterns of HIV drug resistance-associated mutations among children under 18 months of age born to HIV-1-positive mothers enrolled in the prevention of mother-to-child transmission services in Haiti.

METHODS

Between January 1, 2013 and December 31, 2014, HIV-positive remnant dried blood spots collected from children under 18 months of age for Early Infant Diagnosis at the National Public Health Laboratory were used for HIV-1 genotyping. HIV drug resistance mutations were analyzed using the Stanford Drug Resistance HIVdb program.

RESULTS

Of the 3555 dried blood spots collected for Early Infant Diagnosis, 360 (10.1%) were HIV-positive and 355 were available for genotyping. Of these, 304 (85.6%) were successfully genotyped and 217 (71.4%) had ≥1 drug resistance mutation. Mutations conferring resistance to nucleoside reverse transcriptase inhibitor (NRTIs) and non-NRTIs were present in 40.5% (123) and 69.1% (210), respectively. The most frequent mutations were K103N/S (48.0%), M184V (37.5%), G190A/S (15.1%), and Y181C/G/V (14.1%). Predicted drug resistance analysis revealed that 68.8% of the children had high-level resistance to non-NRTIs and 11.5% had intermediate to high-level resistance to abacavir.

CONCLUSIONS

This study showed high rates of resistance to NRTIs and non-NRTIs among newly HIV-diagnosed children in Haiti, suggesting that in the era of "Option B+" (initiation of lifelong combination antiretroviral therapy to pregnant women with HIV), the majority of children who acquire HIV infection through mother-to-child transmission of HIV have resistant HIV. These results have led the National HIV Program to revise the pediatric guidelines to include protease inhibitors in first-line regimens for all HIV-positive newborns.

Outcomes of protease inhibitor-based antiretroviral therapy amongst children and associated-factors in Yaoundé, Cameroon

Background

There are limited data on protease inhibitor (PI)-based antiretroviral therapy (ART) amongst children in resource-limited settings, for informing on optimal paediatric regimens.

Objective

To evaluate therapeutic response to PI-based ART amongst HIV-infected Cameroonian children.

Methods

A retrospective study was conducted amongst children aged 2–18 years receiving a PI-based ART at the Essos Hospital Centre (EHC), Yaounde, Cameroon. Primary end points were therapeutic success on PI-based ART, defined as clinical success (WHO I/II clinical stage), immunological success (CD4 ≥ 500/mm³) and viral suppression (viral load [VL]<1000 copies/ml). Factors associated with therapeutic success were assessed in uni- and multivariate analysis using SPSS software v.2.0; with p<0.05 considered statistically significant.

Results

A total of 71 eligible children on PI-based ART were enrolled (42 on initial and 29 on substituted regimens), with a median age of 8 [IQR: 5–12] years and mean duration on ART of 7 years. Following therapeutic responses, all (100%) experienced clinical success, 95.2% experienced immunological success (91.7% on initial and 97.2% on substituted PI/r-based regimens) and 74.7% viral suppression. In univariate analysis, viral suppression was associated with: younger age (p<0.0001), living with parents as opposed to guardians (p = 0.049), and the educational level (p<0.0001). In multivariate analysis, only the age ranges of 10–14 years (OR: 0.22 [0.07–0.73]) and 15–18 years (OR: 0.08 [0.02–0.57]), were determinants of poor viral suppression.

Conclusion

Among these Cameroonian children, PI-based ART confers favourable clinical and immunological outcomes. The poor rate of viral suppression was mainly attributed to adolescence (10–18 years).

Antiretroviral Resistance Patterns in Children with HIV Infection

PURPOSE OF REVIEW

To provide an update on the patterns of HIV drug resistance in children, including pretreatment drug resistance (PDR) and acquired drug resistance (ADR), focusing on children in low- and middle-income countries (LMICs) for whom empiric first-line (FL) and second-line (SL) antiretroviral regimens are usually recommended.

RECENT FINDINGS

High levels of PDR, particularly to non-nucleoside reverse transcriptase inhibitors (NNRTIs), and poor treatment outcomes on NNRTI-based FL antiretroviral therapy (ART) have been widely reported among infants and young children. There is a paucity of recent data on the use of protease inhibitor (PI)-based FL and SL regimens in children, but studies have reported poor tolerability, adherence problems and the development of PI resistance. Limited access to virological monitoring and HIV drug resistance testing contributes to delays in identifying treatment failure due to ADR and delays in switching to SL regimens in children. Implementation of FL ART regimens that have a higher barrier to developing resistance and are safe and well tolerated is required in order to attain global treatment targets. Although PI-based regimens may be effective as FL or SL treatment in children, lack of appropriate formulations leading to poor tolerability, drug-drug interactions, and cost considerations have negatively impacted their use among children in LMICs. There is hope that dolutegravir-based regimens recommended for children by the World Health Organization will be widely implemented once child-friendly formulations are available, and dosing and safety studies currently underway are completed, and that this will significantly improve treatment outcomes.

HIV Drug Resistance in Adults Receiving Early vs. Delayed Antiretroviral Therapy: HPTN 052

INTRODUCTION

We evaluated HIV drug resistance in adults who received early vs. delayed antiretroviral therapy (ART) in a multinational trial [HIV Prevention Trials Network (HPTN) 052, enrollment 2005-2010]. In HPTN 052, 1763 index participants were randomized to start ART at a CD4 cell count of 350-550 cells/mm (early ART arm) or <250 cells/mm (delayed ART arm). In May 2011, interim study results showed benefit of early ART, and all participants were offered ART regardless of CD4 cell count; the study ended in 2015.

METHODS

Virologic failure was defined as 2 consecutive viral loads >1000 copies/mL >24 weeks after ART initiation. Drug resistance testing was performed for pretreatment (baseline) and failure samples from participants with virologic failure.

RESULTS

HIV genotyping results were obtained for 211/249 participants (128 early ART arm and 83 delayed ART arm) with virologic failure. Drug resistance was detected in 4.7% of participants at baseline; 35.5% had new resistance at failure. In univariate analysis, the frequency of new resistance at failure was lower among participants in the early ART arm (compared with delayed ART arm, P = 0.06; compared with delayed ART arm with ART initiation before May 2011, P = 0.032). In multivariate analysis, higher baseline viral load (P = 0.0008) and ART regimen (efavirenz/lamivudine/zidovudine compared with other regimens, P = 0.024) were independently associated with higher risk of new resistance at failure.

CONCLUSIONS

In HPTN 052, the frequency of new drug resistance at virologic failure was lower in adults with early ART initiation. The main factor associated with reduced drug resistance with early ART was lower baseline viral load.