Despite the success of antiretroviral therapy, a subset of people with HIV experience low-level viraemia (LLV), a challenging condition with inconsistent definitions and management across settings. We conducted a scoping review of the literature and developed international consensus recommendations through a modified Delphi process involving a multidisciplinary panel of experts. Available evidence shows wide variability in definitions of persistent LLV, most commonly encompassing repeated viral loads between 50 and 1000 copies per mL. Outcomes associated with LLV are heterogeneous. Despite associations between LLV at 50-200 copies per mL and virological failure of more than 1000 copies per mL, resistance emergence or adverse clinical outcomes are inconsistent; stronger evidence links LLV of 200-1000 copies per mL to these endpoints. Based on these findings, we propose a pragmatic management framework that includes prompt confirmation of LLV, assessment of adherence and drug interactions, consideration of resistance testing (especially at viral loads of 200-1000 copies per mL), a broader clinical evaluation, individualised treatment optimisation (according to viral load strata, the genetic barrier to resistance of current and potential antiretroviral regimens, and the HIV resistance profile), and individual prevention strategies for viral loads of 200-1000 copies per mL. This international guidance aims to support clinicians in identifying when LLV requires action, reduce variability in clinical practice, and inform management strategies across diverse health-care settings.

[This corrects the article DOI: 10.1371/journal.ppat.1008307.].

Introduction Oxford Nanopore Technologies (ONT) offer sequencing with low-capital-layout sequencing options, which could assist in expanding HIV drug resistance testing to resource limited settings. However, sequence analysis remains time time-consuming and reliant on skilled personnel. Moreover, current ONT bioinformatic pipelines provide a single consensus sequence that is not equivalent to Sanger sequencing, as drug resistance is often detected in mixed populations. We have therefore investigated an integrated bioinformatic pipeline, Nano-RECall, for seamless drug resistance of low read coverage ONT sequence data from affordable Flongle or MinION flow cells. Methods We compared Sanger sequencing to ONT sequencing of the same HIV-1 subtype C polymerase chain reaction (PCR) amplicons, respectively using RECall and the novel Nano-RECall bioinformatics pipelines. Amplicons were from separate assays a) Applied Biosystems HIV-1 Genotyping Kit (ThermoFisher) spanning protease (PR) to reverse transcriptase (RT) (PR-RT) (n=46) and b) homebrew integrase (IN) (n=21). We investigated optimal read-depth by assessing the coefficient of variation (CV) of nucleotide proportions for various read-depths; and between replicates of 400 reads. The agreement between Sanger sequences and ONT sequences were assessed at nucleotide level, and at codon level for Stanford HIV drug resistance database mutations. Results The coefficient of variation of ONT minority variants plateaued after a read depth of 400-fold implying limited benefit of additional depth and replicates of 400 reads showed a CV of ∼6 % for a representative position. The average sequence similarity between ONT and Sanger sequences was 99.3% (95% CI: 99.1-99.4%) for PR-RT and 99.6% (95% CI: 99.4-99.7%) for INT. Drug resistance mutations did not differ for 21 IN sequences; 16 mutations were detected by both ONT- and Sanger sequencing. For the 46 PR and RT sequences, 245 mutations were detected by either ONT or Sanger, of these 238 (97.1%) were detected by both. Conclusions The Nano-RECall pipeline, freely available as a downloadable application on a Windows computer, provides Sanger-equivalent HIV drug resistance interpretation. This novel pipeline combined with a simple workflow and multiplexing samples on ONT flow-cells would contribute to making HIV drug resistance sequencing feasible for resource limited settings.

Resistance to antiretroviral drugs used to treat HIV is an important and evolving concern, particularly in low- and middle-income countries (LMICs) which have been impacted to the greatest extent by the HIV pandemic. Efforts to monitor the emergence and transmission of resistance over the past decade have shown that drug resistance-especially to the nucleoside analogue and non-nucleoside reverse transcriptase inhibitors-can (and have) increased to levels that can jeopardize the efficacy of available treatment options at the population level. The global shift to integrase-based regimens as the preferred first-line therapy as well as technological advancements in the methods for detecting resistance have had an impact in broadening and diversifying the landscape of and use case for HIV drug resistance testing. This review estimates the potential demand for HIV drug resistance tests, and surveys current testing methodologies, with a focus on their application in LMICs.

Objectives: We evaluated the added value of infection control-guided, on demand, and locally performed severe acute respiratory coronavirus virus 2 (SARS-CoV-2) genomic sequencing to support outbreak investigation and control in acute-care settings.Design and setting: This 18-month prospective molecular epidemiology study was conducted at a tertiary-care hospital in Montreal, Canada. When nosocomial transmission was suspected by local infection control, viral genomic sequencing was performed locally for all putative outbreak cases. Molecular and conventional epidemiology data were correlated on a just-in-time basis to improve understanding of coronavirus disease 2019 (COVID-19) transmission and reinforce or adapt control measures.Results: Between April 2020 and October 2021, 6 outbreaks including 59 nosocomial infections (per the epidemiological definition) were investigated. Genomic data supported 7 distinct transmission clusters involving 6 patients and 26 healthcare workers. We identified multiple distinct modes of transmission, which led to reinforcement and adaptation of infection control measures. Molecular epidemiology data also refuted (n = 14) suspected transmission events in favor of community acquired but institutionally clustered cases.Conclusion: SARS-CoV-2 genomic sequencing can refute or strengthen transmission hypotheses from conventional nosocomial epidemiological investigations, and guide implementation of setting-specific control strategies. Our study represents a template for prospective, on site, outbreak-focused SARS-CoV-2 sequencing. This approach may become increasingly relevant in a COVID-19 endemic state where systematic sequencing within centralized surveillance programs is not available.Trial registration: clinicaltrials.gov identifier: NCT05411562

Background & Aims:Direct-acting antiviral (DAA) regimens provide a cure in >95% of patients with chronic HCV infection. However, in some patients in whom therapy fails, resistance-associated substitutions (RASs) can develop, limiting retreatment options and risking onward resistant virus transmission. In this study, we evaluated RAS prevalence and distribution, including novel NS5A RASs and clinical factors associated with RAS selection, among patients who experienced DAA treatment failure. Methods:SHARED is an international consortium of clinicians and scientists studying HCV drug resistance. HCV sequence linked metadata from 3,355 patients were collected from 22 countries. NS3, NS5A, and NS5B RASs in virologic failures, including novel NS5A substitutions, were examined. Associations of clinical and demographic characteristics with RAS selection were investigated. Results:The frequency of RASs increased from its natural prevalence following DAA exposure: 37% to 60% in NS3, 29% to 80% in NS5A, 15% to 22% in NS5B for sofosbuvir, and 24% to 37% in NS5B for dasabuvir. Among 730 virologic failures, most were treated with first-generation DAAs, 94% had drug resistance in ≥1 DAA class: 31% single-class resistance, 42% dual-class resistance (predominantly against protease and NS5A inhibitors), and 21% triple-class resistance. Distinct patterns containing ≥2 highly resistant RASs were common. New potential NS5A RASs and adaptive changes were identified in genotypes 1a, 3, and 4. Following DAA failure, RAS selection was more frequent in older people with cirrhosis and those infected with genotypes 1b and 4. Conclusions:Drug resistance in HCV is frequent after DAA treatment failure. Previously unrecognized substitutions continue to emerge and remain uncharacterized. Lay summary:Although direct-acting antiviral medications effectively cure hepatitis C in most patients, sometimes treatment selects for resistant viruses, causing antiviral drugs to be either ineffective or only partially effective. Multidrug resistance is common in patients for whom DAA treatment fails. Older patients and patients with advanced liver diseases are more likely to select drug-resistant viruses. Collective efforts from international communities and governments are needed to develop an optimal approach to managing drug resistance and preventing the transmission of resistant viruses.

Introduction : Cabotegravir (CAB) is an integrase strand transfer inhibitor (INSTI) formulated as a long-acting injectable drug approved for pre-exposure prophylaxis and use with a long acting rilpivirine formulation for maintenance therapy in patients with virological suppression. However, there has been no comprehensive review of the genetic mechanisms of CAB resistance. Methods : Studies reporting the selection of drug resistance mutations (DRMs) by CAB and the results of in vitro CAB susceptibility testing were reviewed. The impact of integrase mutations on CAB susceptibility was assessed using regularized regression analysis. Results : The most commonly selected mutations in the 24 persons developing virological failure while receiving CAB included Q148R (n=15), N155H (n=7), and E138K (n=5). T97A, G118R, G140A/R/S, and R263K each developed in 1-2 persons. With the exception of T97A, G118R, and G140A/R, these DRMs were also selected in vitro while G140R was selected in the SIV macaque model. Although these DRMs are similar to those occurring in persons receiving the related INSTI dolutegravir, Q148R was more likely to occur with CAB while G118R and R263K were more likely to occur with dolutegravir. Regularized regression analysis identified 15 DRMs significantly associated with reduced CAB susceptibility including seven primary DRMs which reduced susceptibility on their own including G118R, F121C, Q148H/K/R, N155H, and R263K, and eight accessory DRMs including M50I, L74F/M, T97A, E138K, and G140A/C/S. Isolates with Q148H/K/R in combination with L74M, E138A/K, G140A/S, and N155H often had >10-fold reduced CAB susceptibility. M50I, L74M, and T97A are polymorphic mutations that alone did not appear to increase the risk of virological failure in persons receiving a CAB-containing regimen. Conclusions : Careful patient screening is required to prevent CAB from being used during active virus replication. Close virological monitoring is required to minimize CAB exposure to active replication to prevent the emergence of DRMs associated with cross-resistance to other INSTIs.

BackgroundPrevention and management of COVID-19 nosocomial outbreaks is essential to protect patients and healthcare workers, and to maintain clinical care activities. The COVID-19 pandemic exposed challenges faced by conventional hospital epidemiology for identification of healthcare associated infections.MethodsThis is a prospective molecular epidemiology study based at a tertiary care hospital in Montreal, Canada. When nosocomial transmission was suspected by local infection control teams’ investigations, SARS-CoV-2 viral genomic sequencing was performed locally for all putative outbreak cases. Molecular and conventional epidemiology data were rapidly produced and correlated just-in-time to improve understanding of COVID-19 transmission and reinforce or adapt control measures.FindingsBetween April 2020 and October 2021, six outbreaks including 59 nosocomial infections as per the epidemiological definition were investigated. Genomic data supported seven distinct transmission clusters involving 6 patients and 26 healthcare workers. Multiple distinct modes of transmission were identified leading to reinforcement and adaptation of infection control measures. Molecular epidemiology data also refuted (n=14) suspected transmission envents in favor of community acquired but institutionnaly clustered cases.InterpretationOur findings confirm that SARS-CoV-2 genomic sequencing can refute or strenghten transmission hypotheses from conventional nosocomial epidemiological investigations, and guide implementation of setting-specific control strategies. Our study represents a template for prospective, on site, outbreak-focused SARS-CoV-2 sequencing, an approach which may become increasingly relevant in a COVID endemic state where systematic sequencing within centralized surveillance programs is not available.Trial Registration Details: This study protocol was made publicly available on ClinicalTrials.gov under ID NCT05411562.Funding Information: Fonds de Recherche Santé Québec - Réseau SIDA-Maladies Infectieuses (Ref.70142). Centre Hospitalier de l’Université de Montréal (CHUM). Declaration of Interests: All other authors declare no competing interests. Although many co-authors participate on local and national COVID-19 response advisory committees, the presented views on COVID-19 diagnostics and outbreak management are those of the authors and not those of the Public Agency of Canada (PHAC), the Quebec National Institute of Public Health (INSPQ), the Quebec Ministry 450 of Health and Social Services (MSSS) or Quebec Nosocomial Infections Committee (CINQ). SGL is supported by the Fonds de Recherche Santé Québec. CT is supported by the Pfizer-Université de Montréal Chair on HIV translational research. Ethics Approval Statement: This study was performed using clinical information and samples provided to our IPAC service and clinical microbiology laboratory as part of routine outbreak investigations. The study did not require individual informed consent but was approved by CHUM’s Ethic Commitee (Ref. 2021- 9253, 20.270).

INTRODUCTION:Entry inhibitors are a relatively new class of antiretroviral therapy and are typically indicated in heavily treatment experienced individuals living with HIV. Despite this, there is no formal definition of 'heavily treatment experienced'. Interpretation of this term generally includes acknowledgement of multidrug resistance and reflects the fact that patients in need of further treatment options may have experienced multiple lines of therapy. However, it fails to recognize treatment limiting factors including contraindications, age-associated comorbidities, and difficulty adhering to regimens.METHODS:This manuscript follows a roundtable discussion and aims to identify the unmet needs of those living with HIV who are in need of further treatment options, to broaden the definition of heavily treatment experienced and to clarify the use of newer agents, with an emphasis on the potential role of entry inhibitors, in this population.RESULTS/CONCLUSIONS:Within the entry inhibitor class, mechanisms of action differ between agents; resistance to one subclass does not confer resistance to others. Combinations of entry inhibitors should be considered in the same regimen, and if lack of response is seen to one entry inhibitor another can be tried. When selecting an entry inhibitor, physicians should account for patient preferences and needs as well as agent-specific clinical characteristics. Absence of documented multidrug resistance should not exclude an individual from treatment with an entry inhibitor; entry inhibitors are a valuable treatment option for all individuals who are treatment limited or treatment exhausted. We should advocate for additional clinical trials that help define the role of entry inhibitors in people with exhausted/limited ART options other than drug resistance.

The advent of direct-acting antivirals (DAAs) has transformed the treatment landscape of hepatitis C [...].

SARS-CoV-2 whole genome sequencing is a molecular biology tool performed to support many aspects of the response to the pandemic. Freezing of primary clinical nasopharyngeal swabs and shipment to reference laboratories is usually required for sequencing. Cobas PCR Media transport medium facilitates high throughput SARS-CoV-2 RT-PCR analyses on cobas platforms. The manufacturer doesn't recommend freezing this transport medium because of risks of degrading molecular templates and impairing test results. Our objective was to compare the quality and results of SARS-CoV-2 genomic sequencing when performed on fresh or frozen samples in cobas PCR Media. Viral genome sequencing was performed using Oxford Nanopore Technologies MinION platform. Sequencing performance, quality and results did not significantly differ between fresh and frozen samples (n = 10). Freezing of cobas PCR Media does not negatively affect SARS-CoV-2 RNA sequencing results and it is therefore a suitable transport medium for outsourcing sequencing analyses to reference laboratories.

Most individuals chronically infected with hepatitis C virus (HCV) are asymptomatic during the initial stages of infection and therefore the precise timing of infection is often unknown. Retrospective estimation of infection duration would improve existing surveillance data and help guide treatment. While intra-host viral diversity quantifications such as Shannon entropy have previously been utilized for estimating duration of infection, these studies characterize the viral population from only a relatively short segment of the HCV genome. In this study intra-host diversities were examined across the HCV genome in order to identify the region most reflective of time and the degree to which these estimates are influenced by high-risk activities including those associated with HCV acquisition. Shannon diversities were calculated for all regions of HCV from 78 longitudinally sampled individuals with known seroconversion timeframes. While the region of the HCV genome most accurately reflecting time resided within the NS3 gene, the gene region with the highest capacity to differentiate acute from chronic infections was identified within the NS5b region. Multivariate models predicting duration of infection from viral diversity significantly improved upon incorporation of variables associated with recent public, unsupervised drug use. These results could assist the development of strategic population treatment guidelines for high-risk individuals infected with HCV and offer insights into variables associated with a likelihood of transmission.

Objective: Dolutegravir (DTG) is now a preferred component of first-line antiretroviral therapy (ART). However, prevalence data on natural resistance to integrase inhibitors [integrase strand transfer inhibitors (INSTIs)] in circulating non-subtype B HIV-1 in sub-Saharan Africa is scarce. Our objective is to report prevalence of pre-treatment integrase polymorphisms associated with resistance to INSTIs in an ART-naive cohort with diverse HIV-1 subtypes. Design: We retrospectively examined HIV-1 integrase sequences from Uganda. Methods: Plasma samples were derived from the Uganda AIDS Rural Treatment Outcomes (UARTO) cohort, reflecting enrollment from 2002 to 2010, prior to initiation of ART. HIV-1 integrase was amplified using nested-PCR and Sanger-sequenced (HXB2 4230-5093). Stanford HIVdb v8.8 was used to infer clinically significant INSTI-associated mutations. Human leukocyte antigen (HLA) typing was performed for all study participants. Results: Plasma samples from 511 ART-naive individuals (subtype: 48% A1, 39% D) yielded HIV-1 integrase genotyping results. Six out of 511 participants (1.2%) had any major INSTI-associated mutations. Of these, two had E138T (subtype A1), three had E138E/K (subtype D), and one had T66T/I (subtype D). No participants had mutations traditionally associated with high levels of INSTI resistance. HLA genotypes A∗02:01/05/14, B∗44:15, and C∗04:07 predicted the presence of L74I, a mutation recently observed in association with long-acting INSTI cabotegravir virologic failure. Conclusion: We detected no HIV-1 polymorphisms associated with high levels of DTG resistance in Uganda in the pre-DTG era. Our results support widespread implementation of DTG but careful monitoring of patients on INSTI with virologic failure is warranted to determine if unique mutations predict failure for non-B subtypes of HIV-1.

Despite the effectiveness of direct-acting antiviral agents in treating hepatitis C virus (HCV), cases of treatment failure have been associated with the emergence of resistance-associated substitutions. To better guide clinical decision-making, we developed and validated a near-whole-genome HCV genotype-independent next-generation sequencing strategy. HCV genotype 1–6 samples from direct-acting antiviral agent treatment-naïve and -treated HCV-infected individuals were included. Viral RNA was extracted using a NucliSens easyMAG and amplified using nested reverse transcription-polymerase chain reaction. Libraries were prepared using Nextera XT and sequenced on the Illumina MiSeq sequencing platform. Data were processed by an in-house pipeline (MiCall). Nucleotide consensus sequences were aligned to reference strain sequences for resistance-associated substitution identification and compared to NS3, NS5a, and NS5b sequence data obtained from a validated in-house assay optimized for HCV genotype 1. Sequencing success rates (defined as achieving >100-fold read coverage) approaching 90% were observed for most genotypes in samples with a viral load >5 log10 IU/mL. This genotype-independent sequencing method resulted in >99.8% nucleotide concordance with the genotype 1-optimized method, and 100% agreement in genotype assignment with paired line probe assay-based genotypes. The assay demonstrated high intra-run repeatability and inter-run reproducibility at detecting substitutions above 2% prevalence. This study highlights the performance of a freely available laboratory and bioinformatic approach for reliable HCV genotyping and resistance-associated substitution detection regardless of genotype.

Next generation sequencing (NGS) is a trending new standard for genotypic HIV-1 drug resistance (HIVDR) testing. Many NGS HIVDR data analysis pipelines have been independently developed, each with variable outputs and data management protocols. Standardization of such analytical methods and comparison of available pipelines are lacking, yet may impact subsequent HIVDR interpretation and other downstream applications. Here we compared the performance of five NGS HIVDR pipelines using proficiency panel samples from NIAID Virology Quality Assurance (VQA) program. Ten VQA panel specimens were genotyped by each of six international laboratories using their own in-house NGS assays. Raw NGS data were then processed using each of the five different pipelines including HyDRA, MiCall, PASeq, Hivmmer and DEEPGEN. All pipelines detected amino acid variants (AAVs) at full range of frequencies (1~100%) and demonstrated good linearity as compared to the reference frequency values. While the sensitivity in detecting low abundance AAVs, with frequencies between 1~20%, is less a concern for all pipelines, their specificity dramatically decreased at AAV frequencies <2%, suggesting that 2% threshold may be a more reliable reporting threshold for ensured specificity in AAV calling and reporting. More variations were observed among the pipelines when low abundance AAVs are concerned, likely due to differences in their NGS read quality control strategies. Findings from this study highlight the need for standardized strategies for NGS HIVDR data analysis, especially for the detection of minority HIVDR variants.

The ability of HIV-1 to evolve resistance to combined antiretroviral therapies (cARTs) has stimulated research into alternative means of controlling this infection. We assayed >60 modulators of RNA alternative splicing (AS) to identify new inhibitors of HIV-1 RNA processing-a segment of the viral lifecycle not targeted by current drugs-and discovered compound N-[4-chloro-3-(trifluoromethyl)phenyl]-7-nitro-2,1,3-benzoxadiazol-4-amine (5342191) as a potent inhibitor of both wild-type (Ba-L, NL4-3, LAI, IIIB, and N54) and drug-resistant strains of HIV-1 (IC50: ~700 nM) with no significant effect on cell viability at doses tested. 5342191 blocks expression of four essential HIV-1 structural and regulatory proteins (Gag, Env, Tat, and Rev) without affecting total protein synthesis of the cell. This response is associated with altered unspliced (US) and singly-spliced (SS) HIV-1 RNA accumulation (~60% reduction) and transport to the cytoplasm (loss of Rev) whereas parallel analysis of cellular RNAs revealed less than a 0.7% of host alternative splicing (AS) events (0.25-0.67% by ≥ 10-20%), gene expression (0.01-0.46% by ≥ 2-5 fold), and protein abundance (0.02-0.34% by ≥ 1.5-2 fold) being affected. Decreased expression of Tat, but not Gag/Env, upon 5342191 treatment was reversed by a proteasome inhibitor, suggesting that this compound alters the synthesis/degradation of this key viral factor. Consistent with an affect on HIV-1 RNA processing, 5342191 treatment of cells altered the abundance and phosphorylation of serine/arginine-rich splicing factor (SRSF) 1, 3, and 4. Despite the activation of several intracellular signaling pathways by 5342191 (Ras, MEK1/2-ERK1/2, and JNK1/2/3), inhibition of HIV-1 gene expression by this compound could be reversed by pre-treatment with either a G-protein α-subunit inhibitor or two different MEK1/2 inhibitors. These observations demonstrate enhanced sensitivity of HIV-1 gene expression to small changes in host RNA processing and highlights the potential of modulating host intracellular signaling as an alternative approach for controlling HIV-1 infection.

Next-generation sequencing (NGS) is increasingly used for HIV-1 drug resistance genotyping. NGS methods have the potential for a more sensitive detection of low-abundance variants (LAV) compared to standard Sanger sequencing (SS) methods. A standardized threshold for reporting LAV that generates data comparable to those derived from SS is needed to allow for the comparability of data from laboratories using NGS and SS. Ten HIV-1 specimens were tested in ten laboratories using Illumina MiSeq-based methods. The consensus sequences for each specimen using LAV thresholds of 5%, 10%, 15%, and 20% were compared to each other and to the consensus of the SS sequences (protease 4–99; reverse transcriptase 38–247). The concordance among laboratories’ sequences at different thresholds was evaluated by pairwise sequence comparisons. NGS sequences generated using the 20% threshold were the most similar to the SS consensus (average 99.6% identity, range 96.1–100%), compared to 15% (99.4%, 88.5–100%), 10% (99.2%, 87.4–100%), or 5% (98.5%, 86.4–100%). The average sequence identity between laboratories using thresholds of 20%, 15%, 10%, and 5% was 99.1%, 98.7%, 98.3%, and 97.3%, respectively. Using the 20% threshold, we observed an excellent agreement between NGS and SS, but significant differences at lower thresholds. Understanding how variation in NGS methods influences sequence quality is essential for NGS-based HIV-1 drug resistance genotyping.

Abstract BackgroundSeventeen years after the start of the IBAARV (Beninese initiative for access to antiretrovirals), transmitted drug resistance mutations in ARV naïve patients and HIV-1 genetic diversity were investigated in Benin.Methods353 plasma samples were collected between October and December 2017 in nineteen facilities care in Benin from HIV-1 positive and ARV naive individuals. Pol (protease + partial RT) region was amplified and sequenced in 248 samples.ResultsDrug resistance mutations were detected in (27/248; 10.9%) according to the WHO SDRM 2009 list, with predominance of mutations directed to NNRTIs drugs (24/248; 10%).Phylogenetic and recombination analyses showed a predominance of CRF02_AG strains (165/248; 66.5%) and a high genetic diversity with five other variants and 39 URFs (15.7%) which contained portions of strains that co-circulate in Benin. Eight recent transmission chains revealed active ongoing transmission of HIV-1 strains among ARV naïve patients.ConclusionsOur study showed a high primary drug resistance rate and a complex genetic diversity. Regular monitoring of primary drug resistance is required to adapt HIV-1 treatment strategies and adoption of new WHO recommendations in Benin.