High Prevalence of HIV Drug Resistance Among Newly Diagnosed Infants Aged <18 Months: Results From a Nationwide Surveillance in Nigeria

Virologic Outcomes and ARV Switch Profiles 2 Years After National Rollout of Dolutegravir to Children Less Than 15 Years in Southern Mozambique

BACKGROUND

Dolutegravir (DTG) was scaled up globally to optimize treatment for children living with HIV. We evaluated the rollout and virological outcomes after DTG introduction in Mozambique.

METHODS

Data from children 0-14 years with visits from September 2019 to August 2021 were extracted from records in 16 facilities in 12 districts. Among children ever on DTG, we report treatment switches, defined as changes in anchor drug, regardless of changes to nucleoside reverse transcriptase inhibitor (NRTI) backbones. Among those on DTG for ≥6 months, we described viral load suppression rates by children newly initiating and switching to DTG and by the NRTI backbone at the time of the DTG switch.

RESULTS

Overall, 3,347 children were ever on DTG-based treatment (median age 9.5 years; 52.8% female). Most children (3,202, 95.7%) switched to DTG from another antiretroviral regimen. During the 2-year follow-up, 9.9% never switched from DTG; 52.7% had 1 regimen change, of which 97.6% were switched to DTG. However, 37.2% of children experienced ≥2 anchor drug changes. Overall median time on DTG was 18.6 months; nearly all children ≥5 years (98.6%) were on DTG at the last visit. Viral suppression was 79.7% (63/79) for children newly initiating DTG and 85.8% (1,775/2,068) for those switching to DTG. Suppression rates were 84.8% and 85.7% among children who switched and maintained NRTI backbones, respectively.

CONCLUSIONS

Viral suppression rates of ≥80% with minor variations by backbone were achieved during the 2-year DTG rollout. However, there were multiple anchor drug switches for over one-third of children, which may be attributable in part to drug stockouts. Long-term pediatric HIV management will only be successful with immediate and sustainable access to optimized child-friendly drugs and formulations.

"I feel drug resistance testing allowed us to make an informed decision": qualitative insights on the role of HIV drug resistance mutation testing among children and pregnant women living with HIV in western Kenya

BACKGROUND

Pregnant women and children living with HIV in Kenya achieve viral suppression (VS) at lower rates than other adults. While many factors contribute to these low rates, the acquisition and development of HIV drug resistance mutations (DRMs) are a contributing factor. Recognizing the significance of DRMs in treatment decisions, resource-limited settings are scaling up national DRM testing programs. From provider and patient perspectives, however, optimal ways to operationalize and scale-up DRM testing in such settings remain unclear.

METHODS

Our mixed methods study evaluates the attitudes towards, facilitators to, and barriers to DRM testing approaches among children and pregnant women on antiretroviral therapy (ART) in five HIV treatment facilities in Kenya. We conducted 68 key informant interviews (KIIs) from December 2019 to December 2020 with adolescents, caregivers, pregnant women newly initiating ART or with a high viral load, and providers, laboratory/facility leadership, and policy makers. Our KII guides covered the following domains: (1) DRM testing experiences in routine care and through our intervention and (2) barriers and facilitators to routine and point-of-care DRM testing scale-up. We used inductive coding and thematic analysis to identify dominant themes with convergent and divergent subthemes.

RESULTS

The following themes emerged from our analysis: (1) DRM testing and counseling were valuable to clinical decision-making and reassuring to patients, with timely results allowing providers to change patient ART regimens faster; (2) providers and policymakers desired an amended and potentially decentralized DRM testing process that incorporates quicker sample-to-results turn-around-time, less burdensome procedures, and greater patient and provider "empowerment" to increase comfort with testing protocols; (3) facility-level delays, deriving from overworked facilities and sample tracking difficulties, were highlighted as areas for improvement.

CONCLUSIONS

DRM testing has the potential to considerably improve patient health outcomes. Key informants recognized several obstacles to implementation and desired a more simplified, time-efficient, and potentially decentralized DRM testing process that builds provider comfort and confidence with DRM testing protocols. Further investigating the implementation, endurance, and effectiveness of DRM testing training is critical to addressing the barriers and areas of improvement highlighted in our study.

TRIAL REGISTRATION

NCT03820323.

High Drug Resistance Levels Compromise the Control of HIV Infection in Pediatric and Adult Populations in Bata, Equatorial Guinea

A lack of HIV viral load (VL) and HIV drug resistance (HIVDR) monitoring in sub-Saharan Africa has led to an uncontrolled circulation of HIV-strains with drug resistance mutations (DRM), compromising antiretroviral therapy (ART). This study updates HIVDR data and HIV-1 variants in Equatorial Guinea (EG), providing the first data on children/adolescents in the country. From 2019−2020, 269 dried blood samples (DBS) were collected in Bata Regional Hospital (EG) from 187 adults (73 ART-naïve/114 ART-treated) and 82 children/adolescents (25 HIV-exposed-ART-naïve/57 ART-treated). HIV-1 infection was confirmed in Madrid by molecular/serological confirmatory tests and ART-failure by VL quantification. HIV-1 pol region was identified as transmitted/acquired DRM, predicted antiretroviral susceptibility (Stanfordv9.0) and HIV-1 variants (phylogeny). HIV infection was confirmed in 88.1% of the individuals and virological failure (VL > 1000 HIV-1-RNA copies/mL) in 84.2/88.9/61.9% of 169 ART-treated children/adolescents/adults. Among the 167 subjects with available data, 24.6% suffered a diagnostic delay. All 125 treated had experienced nucleoside retrotranscriptase inhibitors (NRTI); 95.2% were non-NRTI (NNRTI); 22.4% had experienced integrase inhibitors (INSTI); and 16% had experienced protease inhibitors (PI). At sampling, they had received 1 (37.6%), 2 (32%), 3 (24.8%) or 4 (5.6%) different ART-regimens. Among the 43 treated children−adolescents/37 adults with sequence, 62.8/64.9% carried viruses with major-DRM. Most harbored DRM to NNRTI (68.4/66.7%), NRTI (55.3/43.3%) or NRTI+NNRTI (50/33.3%). One adult and one child carried major-DRM to PI and none carried major-DRM to INSTI. Most participants were susceptible to INI and PI. DRM was absent in 36.2% of treated patients with VL > 1000 cp/mL, suggesting adherence failure. TDR prevalence in 59 ART-naïve adults was high (20.3%). One-half (53.9%) of the 141 subjects with pol sequence carried CRF02_AG. The observed high rate of ART-failure and transmitted/acquired HIVDR could compromise the 95-95-95-UNAIDS targets in EG. Routine VL and resistance monitoring implementation are mandatory for early detection of ART-failure and optimal rescue therapy selection ART regimens based on PI, and INSTI can improve HIV control in EG.

Fc receptor engagement of HIV-1 Env-specific antibodies in mothers and infants predicts reduced vertical transmission

Introduction

Infants acquire maternal antibodies by Fc receptor transcytosis across the placenta during pregnancy. Fc receptors are expressed on immune cells and are important for activation of effector cell functions.

Methods

In this study, we evaluated Fc receptor engagement and ADCC activity of plasma binding antibodies from human immunodeficiency virus-1 (HIV) -infected mothers and to identify factors that may contribute to protection from HIV vertical transmission.

Results

HIV-specific binding and Fc receptor engagement of plasma antibodies varied between mothers by transmission status and infants by infection status. Non-transmitting (NT) mothers and HIV-uninfected infants had antibodies with higher neonatal Fc receptor (FcRn) and FcγR engagement, as compared to transmitting (T) mothers and HIV+ infants, respectively. A significant inverse correlation between plasma antibody FcRn and FcγR engagement was observed for T mothers, but not NT mothers. Conversely, a significant direct correlation was observed between plasma antibody FcRn and FcγR engagement for HIV- infants, but not for HIV+ infants. Consequently, we observed significantly higher plasma antibody ADCC potency and breadth in HIV- infants, as compared to HIV+ infants. However, no differences in overall ADCC potency and breadth were observed between mothers. FcRn-engagement of HIV-specific antibodies in both mothers and infants predicted a lack of vertical transmission of HIV.

Discussion

This study indicates that HIV-uninfected infants acquire HIV-specific antibodies with greater Fc receptor engagement and thus, greater ADCC capacity.

Point-of-care HIV viral load and targeted drug resistance mutation testing versus standard care for Kenyan children on antiretroviral therapy (Opt4Kids): an open-label, randomised controlled trial

BACKGROUND

Feasible, scalable, and cost-effective approaches to ensure virological suppression among children living with HIV are urgently needed. The aim of the Opt4Kids study was to determine the effect of point of care viral load and targeted drug resistance mutation testing in improving virological suppression among children on antiretroviral therapy (ART) in Kenya.

METHODS

In this open-label, individually randomised controlled trial, we enrolled children living with HIV aged 1-14 years and who were either newly initiating or already receiving ART at five study facilities in Kenya. Participants were randomly allocated 1:1 to receive the intervention of point-of-care viral load testing every 3 months, targeted drug resistance mutation testing, and clinical decision support (point-of-care testing) or to receive the standard care (control group), stratified by facility site and age groups (1-9 years vs 10-14 years). Investigators were masked to the randomised group. The primary efficacy outcome was virological suppression (defined as a viral load of <1000 copies per mL) by point-of-care viral load testing at 12 months after enrolment in all participants with an assessment. This study is registered with ClinicalTrials.gov, NCT03820323.

FINDINGS

Between March 7, 2019, and December 31, 2020, we enrolled 704 participants. Median age at enrolment was 9 years (IQR 7-12), 344 (49%) participants were female and 360 (51%) were male, and median time on ART was 5·8 years (IQR 3·1-8·6). 536 (76%) of 704 had documented virological suppression at enrolment. At 12 months after enrolment, the proportion of participants achieving virological suppression in the intervention group (283 [90%] of 313 participants with a 12 month point-of-care viral load test) did not differ from that in the control group (289 [92%] of 315; risk ratio [RR] 0·99, 95% CI 0·94-1·03; p=0·55). We identified 138 episodes of viraemia in intervention participants, of which 107 (89%) samples successfully underwent drug resistance mutation testing and 91 (85%) had major drug resistance mutations. The median turnaround time for viral load results was 1 day (IQR 0-1) in the intervention group and 15 days (10-21) in the control group.

INTERPRETATION

Point-of-care viral load testing decreased turnaround time and targeted drug resistance mutation testing identified a high prevalence of HIV drug resistance mutations in children living with HIV, but the combined approach did not increase rates of virological suppression. Further research in combination interventions, including point-of-care viral load and drug resistance mutation testing coupled with psychosocial support, is needed to optimise virological suppression for children living with HIV.

FUNDING

National Institutes of Mental Health of the US National Institutes of Health, Thrasher Research Fund.

Pretreatment HIV drug resistance among treatment naïve infants newly diagnosed with HIV in 2016 in Namibia: results of a nationally representative study

Background

The World Health Organization (WHO) recommends routine surveillance of pretreatment human immunodeficiency virus (HIV) drug resistance (HIVDR) in children <18 months of age diagnosed with HIV through early infant diagnosis (EID). In 2016, 262 children <18 months of age were diagnosed with HIV in Namibia through EID. Levels of HIVDR in this population are unknown.

Methods

In 2016, Namibia surveyed pretreatment HIVDR among children aged <18 months following WHO guidance. Reverse transcriptase, protease, and integrase regions of HIV-1 were genotyped from remnant dried blood spot specimens from all infants diagnosed with HIV in Namibia in 2016. HIVDR was predicted using the Stanford HIVdb algorithm.

Results

Of 262 specimens genotyped, 198 HIV-1 protease and reverse transcriptase sequences and 118 HIV-1 integrase sequences were successfully amplified and analyzed. The prevalence of efavirenz/nevirapine (EFV/NVP), abacavir (ABC), zidovudine, lamivudine/emtricitabine (3TC/FTC), and tenofovir (TDF) resistance was 62.6%, 17.7%, 5.6%, 15.7%, and 10.1%, respectively. No integrase inhibitor resistance was detected.

Conclusions

The high level of EFV/NVP resistance is unsurprising; however, levels of ABC and TDF resistance are among the highest observed to date in infants in sub-Saharan Africa. The absence of resistance to dolutegravir (DTG) is reassuring but underscores the need to further study the impact of ABC and 3TC/FTC resistance on pediatric protease inhibitor– and DTG-based regimens and accelerate access to other antiretroviral drugs. Results underscore the need for antiretroviral therapy optimization and prompt management of high viral loads in infants and pregnant and breastfeeding women.

Surveillance of Pretreatment Drug Resistance Among HIV-Infected Children in Ibadan, Nigeria

There are about 2.1 million children infected with HIV globally and about 120,000 deaths annually. Nigeria has one of the highest rates of pediatric HIV infection globally. Pretreatment HIV drug resistance data inform the choice of first- and second-line antiretroviral therapy (ART) regimens. This study investigated the prevalence of HIV drug-resistant strains among ART-naive children in Ibadan, Nigeria. A total of 20 children aged <15 years were enrolled. Demographic, clinical, and laboratory data were documented. Total nucleic acid was extracted from blood samples after which amplification of HIV-1 pol gene was done using polymerase chain reaction. Amplified gene was sequenced using big dye sequencing method. The sequenced HIV-1 pol gene was typed and analyzed for identification of mutations indicative of drug resistance across the different classes of ART. HIV-1 RNA pol gene was successfully amplified in 12/20 (60%) children. All were identified as HIV-1 and the subtypes were G and CRF 02AG, recombinant of 02_AG/G and recombinant of 02_AG/A1. Drug-resistant mutations (DRMs) were identified in 4/12 (33%). Three out of the four mutations were identified as non-nucleoside reverse transcriptase inhibitors DRM (K103N), whereas the fourth had nucleoside reverse transcriptase inhibitors DRM (M184V). Results from this preliminary study show that drug resistance among ART-naive children is a problem in Ibadan. Pretreatment drug resistance testing is desirable in children before initiation of ART to guide effective treatment.

Multilevel modelling and multiple group analysis of disparities in continuity of care and viral suppression among adolescents and youths living with HIV in Nigeria

INTRODUCTION

Substantial disparities in care outcomes exist between different subgroups of adolescents and youths living with HIV (AYLHIV). Understanding variation in individual and health facility characteristics could be key to identifying targets for interventions to reduce these disparities. We modelled variation in AYLHIV retention in care and viral suppression, and quantified the extent to which individual and facility characteristics account for observed variations.

METHODS

We included 1170 young adolescents (10-14 years), 3206 older adolescents (15-19 years) and 9151 young adults (20-24 years) who were initiated on antiretroviral therapy (ART) between January 2015 and December 2017 across 124 healthcare facilities in Nigeria. For each age group, we used multilevel modelling to partition observed variation of main outcomes (retention in care and viral suppression at 12 months after ART initiation) by individual (level one) and health facility (level two) characteristics. We used multiple group analysis to compare the effects of individual and facility characteristics across age groups.

RESULTS

Facility characteristics explained most of the observed variance in retention in care in all the age groups, with smaller contributions from individual-level characteristics (14%-22.22% vs 0%-3.84%). For viral suppression, facility characteristics accounted for a higher proportion of variance in young adolescents (15.79%), but not in older adolescents (0%) and young adults (3.45%). Males were more likely to not be retained in care (adjusted OR (aOR)=1.28; p<0.001 young adults) and less likely to achieve viral suppression (aOR=0.69; p<0.05 older adolescent). Increasing facility-level viral load testing reduced the likelihood of non-retention in care, while baseline regimen TDF/3TC/EFV or NVP increased the likelihood of viral suppression.

CONCLUSIONS

Differences in characteristics of healthcare facilities accounted for observed disparities in retention in care and, to a lesser extent, disparities in viral suppression. An optimal combination of individual and health services approaches is, therefore, necessary to reduce disparities in the health and well-being of AYLHIV.

HIV Drug Resistance in Children and Adolescents: Always a Challenge?

Purpose of Review

With the expanded roll-out of antiretrovirals for treatment and prevention of HIV during the last decade, the emergence of HIV drug resistance (HIVDR) has become a growing challenge. This review provides an overview of the epidemiology and trajectory of HIVDR globally with an emphasis on pediatric and adolescent populations.

Recent Findings

HIVDR is associated with suboptimal virologic suppression and treatment failure, leading to an increased risk of HIV transmission to uninfected people and increased morbidity and mortality among people living with HIV. High rates of HIVDR to non-nucleoside reverse transcriptase inhibitors globally are expected to decline with the introduction of the integrase strand transfer inhibitors and long-acting combination regimens, while challenge remains for HIVDR to other classes of antiretroviral drugs.

Summary

We highlight several solutions including increased HIV viral load monitoring, expanded HIVDR surveillance, and adopting antiretroviral regimens with a high-resistance barrier to decrease HIVDR. Implementation studies and programmatic changes are needed to determine the best approach to prevent and combat the development of HIVDR.

High nonnucleoside reverse transcriptase inhibitor resistance levels in HIV-1-infected Zambian mother-infant pairs

OBJECTIVE(S)

To elucidate relationships in antiretroviral resistance between HIV-1-infected mother-infant pairs by defining the resistance profiles in the mothers and infants and quantifying drug resistance prevalence in the pairs post-Option B+ implementation.

DESIGN

Collection of dried blood spots from mother-infant pairs during routine HIV-1 screens in Lusaka, Zambia from 2015 to 2018.

METHODS

DNA was extracted from the dried blood spots, the HIV-1 pol region was amplified, and the purified proviral DNA was sequenced using Sanger sequencing. Drug resistance mutations (DRM) were identified in sequenced DNA using the Stanford HIVdb (https://hivdb.stanford.edu/).

RESULTS

DRM were detected in 45% (44/97) of samples, and these samples were found to harbor resistance to at least two antiretrovirals. The prevalence of nonnucleoside reverse transcriptase inhibitor resistance was significantly higher than that of other antiretroviral classes. DRM were detected disproportionately in infants (67%; 33/49) compared with mothers (23%; 11/48), but the magnitude of resistance did not differ when resistance was detected. The disparity in drug resistance profiles was reinforced in pairwise comparison of resistance profiles in mother-infant pairs.

CONCLUSION

While Option B+ is effective in reducing mother-to-child transmission, in cases where this regimen fails, high-level nonnucleoside reverse transcriptase inhibitor resistance is frequently detected in infants. This underscores the importance of pretreatment drug resistance screening in both mothers and infants and emphasizes the necessary change to protease inhibitor-based and integrase inhibitor-based regimens for treatment of HIV-1-infected infants and mothers.

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.

Pre-treatment drug resistance and HIV-1 subtypes in infants from Argentina with and without exposure to antiretroviral drugs for prevention of mother-to-child transmission

OBJECTIVES

To assess the prevalence and patterns of pre-treatment HIV drug resistance (PDR) and HIV-1 subtype in infants from Argentina with exposure to different antiretroviral drugs (ARVs) for the prevention of mother-to-child transmission (PMTCT).

PATIENTS AND METHODS

HIV-1 genotyping was performed in 115 infants (median age = 2.3 months) born between 2007 and 2014 to screen for drug resistance mutations (DRMs) before starting first-line ART. HIV-1 subtype was characterized by phylogenetic and recombination analysis.

RESULTS

Overall, DRMs were found in 34 of 115 infants (PDR level 30% to any ARV, 3.5% to PIs, 12% to NRTIs and 22% to NNRTIs). Of the 115 infants, 22 (19.1%) were ARV-unexposed. Another 93 were ARV-exposed: 28 (24.3%) to short-course zidovudine monotherapy ARV prophylaxis; 25 (21.7%) to nevirapine-based ARV prophylaxis; 12 (10.4%) to perinatal infant zidovudine prophylaxis + maternal combination ART with NNRTIs; and 28 (24.3%) to perinatal infant zidovudine prophylaxis+maternal combination ART with PIs. Transmitted drug resistance among ARV-unexposed infants was 32% (5% to PIs, 9% to NRTIs and 18% to NNRTIs). ART-exposed infants showed multi-class ARV resistance. Importantly, vertical transmission of a triple-class-resistant virus was confirmed in one case. Patterns of DRMs predicted high-level resistance to NNRTIs in a similar and high proportion (>50%) of infants with at least one DRM independently of ARV exposure. BF recombinants were found in 74%, subtype B in 20%, subtype C in 3% and novel AG and AB recombinants in 3%.

CONCLUSIONS

PDR in HIV-1-infected children from Argentina is among the highest reported, jeopardizing successful lifelong suppressive ART as well as the efficacy of current PMTCT regimens.

Association between HIV-1 subtype and drug resistance in Nigerian infants

Background

Many lines of evidence point to HIV-1 subtype-specific differences in the development of drug resistance mutations. While variation between subtype C and others has been extensively explored, there has been less emphasis on subtypes common to West Africa. We examined a previously described national survey of pretreatment drug resistance in HIV-1-infected Nigerian children aged <18 months, to explore the association between subtypes and patterns of resistance.

Methods

Five hundred and forty-nine dried blood spots, from 15 early infant diagnostic facilities in Nigeria, were amplified and HIV-1 polymerase was sequenced. Four hundred and twenty-four were analysed for surveillance drug resistance mutations (SDRMs). Associations between subtype and SDRMs were evaluated by Fisher's exact test and logistic regression analysis, controlling for geographical region and exposure.

Results

Using the sub-subtypes of HIV-1 G defined by Delatorre et al. (PLoS One 2014.

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e98908) the most common subtypes were CRF02_AG (174, 41.0%), GWA-I (128, 30.2%), GWA-II (24, 5.7%), GCA (11, 2.6%), A (21, 5.0%) and CRF06_cpx (18, 4.2%). One hundred and ninety infants (44.8%) had ≥1 NNRTI mutation, 92 infants (21.7%) had ≥1 NRTI mutation and 6 infants (1.4%) had ≥1 PI mutation. By logistic regression, 67N was more common in GWA-II/GCA than CRF02_AG (OR 12.0, P = 0.006), as was 70R (OR 23.1, P = 0.007), 184I/V (OR 2.92, P = 0.020), the presence of ≥1 thymidine analogue mutation (TAM) (OR 3.87, P = 0.014), ≥1 type 2 TAM (OR 7.61, P = 0.001) and ≥1 NRTI mutation (OR 3.26, P = 0.005).

Conclusions

This dataset reveals differences among SDRMs by subtype; in particular, between the GWA-II and GCA subclades, compared with CRF02_AG and GWA-I.

Pretreatment HIV drug resistance among adults initiating ART in Namibia

Background

Continued use of standardized, first-line ART containing NNRTIs and NRTIs may contribute to ongoing emergence of HIV drug resistance (HIVDR) in Namibia.

Methods

A nationally representative cross-sectional survey was conducted during 2015-16 to estimate the prevalence of significant pretreatment HIV drug resistance (PDR) and viral load (VL) suppression rates 6-12 months after initiating standardized first-line ART. Consenting adult patients (≥18 years) initiating ART were interviewed about prior antiretroviral drug (ARV) exposure and underwent resistance testing using dried blood spot samples. PDR was defined as mutations causing low-, intermediate- and high-level resistance to ARVs according to the 2014 WHO Surveillance of HIV Drug Resistance in Adults Initiating ART. The prevalence of PDR was described by patient characteristics, ARV exposure and VL results. Results were weighted to be nationally representative.

Results

Successful genotyping was performed for 381 specimens; 144 (36.6%) specimens demonstrated HIVDR, of which 54 (12.7%) demonstrated PDR. Resistance to NNRTIs was most prevalent (11.9%). PDR was higher in patients with previous ARV exposure compared with no exposure (30.5% versus 9.6%) (prevalence ratio = 3.17; P < 0.01).

Conclusions

This survey demonstrated overall PDR at >10% among adults initiating ART in Namibia. Patients with prior ARV exposure had higher rates of PDR. Introducing a non-NNRTI-based regimen for first-line ART should be considered to maximize benefit of ART and minimize the emergence of HIVDR.

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.

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.

An evaluation of elvitegravir plus cobicistat plus tenofovir alafenamide plus emtricitabine as a single-tablet regimen for the treatment of HIV in children and adolescents

INTRODUCTION

Approximately 2.1 million of the estimated 36 million infected with HIV are children or adolescents. International guidelines for HIV-1 Infection suggest starting antiretrovirals (ARV) at the moment of diagnosis. Many factors limit the optimization of antiretroviral therapy in children and adolescents: lack of pediatric formulations, poor adherence, metabolic and pharmacokinetic changes associated withnormal child development and puberty. Areas covered: Three integrase inhibitors are approved by the US Food and Drug Administration and by European Medical Agency for children and adolescents with HIV-1 infection. Raltegravir is approved for children aged 4 weeks to 18 years, while dolutegravir and elvitegravir co-formulated with cobicistat, emtricitabine, and tenofovir alafenamide (E/C/FTC/TAF) are approved for children from 6 years of age. This article evaluates E/C/FTC/TAF as a treatment option. Expert opinion: E/C/FTC/TAF was well tolerated, and the antiretroviral activity and tolerability data of this combination support the use in children and adolescents. However, the studies regarding E/C/FTC/TAF in children and adolescents are scant. Consequently, additional studies investigating its safety and efficacy in children are paramount.

Validation and clinical application of a novel LC-MS method for quantification of dolutegravir in breast milk

Aim: A novel, sensitive and reproducible method for quantification of dolutegravir (DTG) in dried breast milk spots (DBMS) was developed and validated for use in clinical studies. Its application enabled measurement of DTG pharmacokinetics in breastfeeding mothers and their infants. Results/methodology: Sample extraction was by liquid-liquid extraction using tert-butyl methy-ether, with DTG-d5 as an internal standard. DTG was eluted on a reverse phase C18 Waters XBridge (3.5 μm: 2.1 × 50 mm) column using a gradient mobile phase consisting of 0.1% formic acid in deionised water or methanol. The assay was validated over a calibration range of 10-4000 ng/ml. Conclusion: Stability, inter and intra-assay variability were acceptable according to FDA and EMA bioanalytical method guidelines. The assay is robust, accurate, precise and can be reliably applied for analysis of clinical samples in trials from low resource settings.