Prevalence of HIV-1 drug resistance in treated patients with viral load >50 copies/mL in 2009: a French nationwide study

Epidemiological and virological characteristics of people living with HIV on antiretroviral treatment for more than 6 months in virological failure in Brazzaville, Republic of Congo

Introduction. Virological failure is one of the main causes of failing to treat, and better management of HIV infection requires understanding and controlling the factors that contribute to this phenomenon. The main objective was to characterize the patients of the active file of the Brazzaville Outpatient Treatment Center in virological failure to identify predictive factors leading to virological failure. Methods. Conducted between June and December 2020, this was a cross-sectional study. Patients enrolled were HIV-1-infected patients from the Brazzaville Outpatient Treatment Center receiving a potent combination therapy for at least 6 months but experiencing virological failure. Viral load was measured using the automated Abbott Real-time HIV-1 m2000rt System. Sociodemographic and clinical data were collected from a computerized patient record software called Santia. For the identification of the independent predictors of virological failure, statistical analysis was performed. Results. A total of 109 patients with virological failure were recruited. The median age of the patients was 45 years (interquartile range: 37-52 years) and women were more represented (74%). More than half of the patients had World Health Organization stage IV HIV and the median duration of antiretroviral treatment was 96 months. The most followed treatment regimen was AZT+3TC+EFV (or nevirapine) with 48%, while the median viral load was 12985 copies ml-1. Conclusion. In our study, we did not identify any sociodemographic or clinical variables predictive of virological failure. However, we felt that it would be desirable to carry out a study with temporal follow-up and the possibility of sequencing in order to identify the different circulating genotypes and resistance mutations.

Long-term follow-up of HIV-1 multi-drug-resistant treatment-experienced participants treated with etravirine, raltegravir and boosted darunavir: towards drug-reduced regimen? ANRS CO3 Aquitaine Cohort 2007-2018

OBJECTIVE

To assess the efficacy of raltegravir, etravirine and darunavir/ritonavir (TRIO regimen) in treatment-experienced patients with human immunodeficiency virus-1 (HIV-1) infection by describing the proportion of patients who experienced virological failure (VF) at Week 24. The secondary objectives were to assess the HIV-1 plasma viral load (pVL) after Week 24, the proportion of patients who were receiving dual therapy or monotherapy at the last visit, and the number of deaths.

METHODS

Patients from the ANRS CO3 Aquitaine Cohort who were prescribed the TRIO regimen between February 2007 and September 2018 were classified into two groups based on their pVL at study inclusion: the virological failure group (VFG; pVL >50 copies/mL) and the virologically suppressed group (VSG; pVL <50 copies/mL). The impact of baseline pVL and genotypic susceptibility score (GSS) on VF was analysed.

RESULTS

In total, 184 patients were enrolled in this study, with 123 (66.8%) in the VFG and 61 (33.2%) in the VSG. The median length of follow-up was 7.5 (interquartile range 4.1-9.6) years, and 29 (15.8%) patients died. Thirty-seven (25.5%) patients experienced VF at Week 24, including 32/145 (32.7%) in the VFG and 5/47 (10.6%) in the VSG (P<0.01). Resistance-associated mutations were detected in integrase, reverse transcriptase and protease for 7/37 (18.9%), 3/37 (8.1%) and 1/37 (2.7%) patients, respectively. High pVL and GSS at baseline were independently associated with VF. At the last visit, 76/184 (41.3%) patients were still receiving the TRIO regimen, while 55/184 (29.9%) were receiving dual therapy and 1/184 (0.5%) was receiving protease inhibitor monotherapy. Among the 56 patients receiving dual therapy or monotherapy, 51 (96.2%) had pVL <50 copies/mL.

CONCLUSION

Despite a high level of mutation resistance at baseline, long-term virological follow-up was favourable and one-third of patients were eligible for drug-reducing strategies.

HIV-1C in-House RNA-Based Genotyping Assay for Detection of Drug Resistance Mutations in Samples with Low-Level Viral Loads

Purpose

Monitoring HIV-1 drug resistance mutations (DRM) in treated patients on combination antiretroviral therapy (cART) with a detectable HIV-1 viral load (VL) is important for the selection of appropriate cART. Currently, there is limited data on HIV DRM at low-level viremia (LLV) (VL 401-999 copies/mL) due to the use of a threshold of VL ≥1000 copies/mL for HIV DRM testing. We here assess the performance of an in-house HIV drug resistance genotyping assay using plasma for the detection of DRM at LLV.

Methods

We used a total of 96 HIV plasma samples from the population-based Botswana Combination Prevention Project (BCPP). The samples were stratified by VL groups: 50 samples had LLV, defined as 401-999 copies/mL, and 46 had ≥1000 copies/mL. HIV pol (PR and RT) region was amplified and sequenced using an in-house genotyping assay with BigDye sequencing chemistry. Known HIV DRMs were identified using the Stanford HIV Drug Resistance Database. Genotyping success rate between the two groups was estimated and compared using the comparison of proportions test.

Results

The overall genotyping success rate was 79% (76/96). For VL groups, the genotyping success was 72% (36/50) at LLV and 87% (40/46) at VL ≥1000 copies/mL. Among generated sequences, the overall prevalence of individuals with at least 1 major or intermediate-associated DRM was 24% (18/76). The proportions of NNRTI-, NRTI- and PI-associated resistance mutations were 28%, 24%, and 0%, respectively. The most predominant mutations detected were K103N (18%) and M184V (12%) in NNRTI- and NRTI-associated mutations, respectively. The prevalence of DRM was 17% (6/36) at LLV and 30% (12/40) at VL ≥1000 copies/mL.

Conclusion

The in-house HIV genotyping assay successfully genotyped 72% of LLV samples and was able to detect 17% of DRM amongst them. Our results highlight the possibility and clinical significance of genotyping HIV among individuals with LLV.

Genetic Diversity and Acquired Drug Resistance Mutations Detected by Deep Sequencing in Virologic Failures among Antiretroviral Treatment Experienced Human Immunodeficiency Virus-1 Patients in a Pastoralist Region of Ethiopia

Purpose

This study was conducted to investigate the drug resistance mutations and genetic diversity of HIV-1 in ART experienced patients in South Omo, Ethiopia.

Patients and Methods

A cross-sectional study conducted on 253 adult patients attending ART clinics for ≥6 months in South Omo. Samples with VL ≥1000 copies/mL were considered as virological failures (VF) and their reverse transcriptase gene codons 90–234 were sequenced using Illumina MiSeq. MinVar was used for the identification of the subtypes and drug resistance mutations. Phylogenetic tree was constructed by neighbor-joining method using the maximum likelihood model.

Results

The median duration of ART was 51 months and 18.6% (47/253) of the patients exhibited VF. Of 47 viraemic patients, the genome of 41 were sequenced and subtype C was dominant (87.8%) followed by recombinant subtype BC (4.9%), M-09-CPX (4.9) and BF1 (2.4%). Of 41 genotyped subjects, 85.4% (35/41) had at least one ADR mutation. Eighty-one percent (33/41) of viraemic patients harbored NRTI resistance mutations, and 48.8% (20/41) were positive for NNRTI resistance mutations, with 43.9% dual resistance mutations. Among NRTI resistance mutations, M184V (73.2%), K219Q (63.4%) and T215 (56.1%) complex were the most mutated positions, while the most common NNRTI resistance mutations were K103N (24.4%), K101E, P225H and V108I 7.5% each. Active tuberculosis (aOR=13, 95% CI= 3.46–29.69), immunological failure (aOR=3.61, 95% CI=1.26–10.39), opportunistic infections (aOR=8.39, 95% CI= 1.75–40.19), and poor adherence were significantly associated with virological failure, while rural residence (aOR 2.37; 95% CI: 1.62–9.10, P= 0.05), immunological failures (aOR 2.37; 95% CI: 1.62–9.10, P= 0.05) and high viral load (aOR 16; 95% CI: 5.35 51.59, P <0.001) were predictors of ADR mutation among the ART experienced and viraemic study subjects.

Conclusion

The study revealed considerable prevalence of VF and ADR mutation with the associated risk indicators. Regular virological monitoring and drug resistance genotyping methods should be implemented for better ART treatment outcomes of the nation.

Prevalence of HIV-1 drug resistance in treated patients with viral load >50 copies/mL: a 2014 French nationwide study

Background

Surveillance of HIV-1 resistance in treated patients with a detectable viral load (VL) is important to monitor, in order to assess the risk of spread of resistant viruses and to determine the proportion of patients who need new antiretroviral drugs with minimal cross-resistance.

Methods

The HIV-1 protease and reverse transcriptase (RT) and integrase genes were sequenced in plasma samples from 782 consecutive patients on failing antiretroviral regimens, seen in 37 specialized centres in 2014. The genotyping results were interpreted using the ANRS v24 algorithm. Prevalence rates were compared with those obtained during a similar survey conducted in 2009.

Results

The protease and RT sequences were obtained in 566 patients, and the integrase sequence in 382 patients. Sequencing was successful in 60%, 78%, 78% and 87% of patients with VLs of 51-200, 201-500, 501-1000 and >1000 copies/mL, respectively. Resistance to at least one antiretroviral drug was detected in 56.3% of samples. Respectively, 3.9%, 8.7%, 1.5% and 3.4% of patients harboured viruses that were resistant to any NRTI, NNRTI, PI and integrase inhibitor (INI). Resistance rates were lower in 2014 than in 2009. Resistance was detected in 48.5% of samples from patients with a VL between 51 and 200 copies/mL.

Conclusion

In France in 2014, 90.0% of patients in AIDS care centres were receiving antiretroviral drugs and 12.0% of them had VLs >50 copies/mL. Therefore, this study suggests that 6.7% of treated patients in France might transmit resistant strains. Resistance testing may be warranted in all treated patients with VL > 50 copies/mL.

Visual analogue scale (VAS) measurement of antiretroviral adherence in people living with HIV (PLWH): a meta-analysis

Effective treatment of HIV hinges upon maintaining adequate antiretroviral therapy adherence. Accurate, cost-effective measurement of medication adherence is needed to best respond to the HIV pandemic. The visual analogue scale (VAS) appears to be a simple and easy to use measure of adherence but the current literature on its use is mixed. This meta-analysis (1) describes VAS concordance with other measures of medication adherence and viral load; and (2) examines how research methods moderate the reported strength of the VAS-viral load relationship. Literature searches were conducted electronically and by hand with a total of 20 studies included in the present study. The VAS showed large strength associations with most other measures of adherence and a smaller association with viral load. More rigorous methodological quality significantly improved the VAS-viral load effect size. We conclude with optimization recommendations for VAS use in clinical practice and research design.

HIV-1 low copy viral sequencing-A prototype assay

In HIV-1 patients with low viral burden, sequencing is often problematic, yet important. This study presents a sensitive, sub-type independent system for sequencing of low level viremia. Sequencing data from 32 HIV-1 infected patients with low level viremia were collected longitudinally. A combination of ViroSeq® HIV-1 Genotyping System and an in-house nesting protocol was used. Eight sub-types were represented. The success-rate of amplification of both PR and RT in the same sample was 100% in samples with viral loads above 100 copies/ml. Below 100 copies/ml, this study managed to amplify both regions in 7/13 (54%) samples. The assays were able to amplify either PR or RT in all sub-types included but one sub-type A specimen. In conclusion, this study presents a promising, simple assay to increase the ability to perform HIV-1 resistance testing at low level viremia. This is a prototype assay and the method needs further testing to evaluate clinical performance.

Antiretroviral-naive and -treated HIV-1 patients can harbour more resistant viruses in CSF than in plasma

OBJECTIVES

The neurological disorders in HIV-1-infected patients remain prevalent. The HIV-1 resistance in plasma and CSF was compared in patients with neurological disorders in a multicentre study.

METHODS

Blood and CSF samples were collected at time of neurological disorders for 244 patients. The viral loads were >50 copies/mL in both compartments and bulk genotypic tests were realized.

RESULTS

On 244 patients, 89 and 155 were antiretroviral (ARV) naive and ARV treated, respectively. In ARV-naive patients, detection of mutations in CSF and not in plasma were reported for the reverse transcriptase (RT) gene in 2/89 patients (2.2%) and for the protease gene in 1/89 patients (1.1%). In ARV-treated patients, 19/152 (12.5%) patients had HIV-1 mutations only in the CSF for the RT gene and 30/151 (19.8%) for the protease gene. Two mutations appeared statistically more prevalent in the CSF than in plasma: M41L (P=0.0455) and T215Y (P=0.0455).

CONCLUSIONS

In most cases, resistance mutations were present and similar in both studied compartments. However, in 3.4% of ARV-naive and 8.8% of ARV-treated patients, the virus was more resistant in CSF than in plasma. These results support the need for genotypic resistance testing when lumbar puncture is performed.

French 2013 guidelines for antiretroviral therapy of HIV-1 infection in adults

Introduction

These guidelines are part of the French Experts’ recommendations for the management of people living with HIV/AIDS, which were made public and submitted to the French health authorities in September 2013. The objective was to provide updated recommendations for antiretroviral treatment (ART) of HIV-positive adults. Guidelines included the following topics: when to start, what to start, specific situations for the choice of the first session of antiretroviral therapy, optimization of antiretroviral therapy after virologic suppression, and management of virologic failure.

Methods

Ten members of the French HIV 2013 expert group were responsible for guidelines on ART. They systematically reviewed the most recent literature. The chairman of the subgroup was responsible for drafting the guidelines, which were subsequently discussed within, and finalized by the whole expert group to obtain a consensus. Recommendations were graded for strength and level of evidence using predefined criteria. Economic considerations were part of the decision-making process for selecting preferred first-line options. Potential conflicts of interest were actively managed throughout the whole process.

Results

ART should be initiated in any HIV-positive person, whatever his/her CD4 T-cell count, even when >500/mm³. The level of evidence of the individual benefit of ART in terms of mortality or progression to AIDS increases with decreasing CD4 cell count. Preferred initial regimens include two nucleoside reverse transcriptase inhibitors (tenofovir/emtricitabine or abacavir/lamivudine) plus a non-nucleoside reverse transcriptase inhibitor (efavirenz or rilpivirine), or a ritonavir-boosted protease inhibitor (atazanavir or darunavir). Raltegravir, lopinavir/r, and nevirapine are recommended as alternative third agents, with specific indications and restrictions. Specific situations such as HIV infection in women, primary HIV infection, severe immune suppression with or without identified opportunistic infection, and person who injects drugs are addressed. Options for optimization of ART once virologic suppression is achieved are discussed. Evaluation and management of virologic failure are described, the aim of any intervention in such situation being to reduce plasma viral load to <50 copies/ml.

Conclusion

These guidelines recommend that any HIV-positive individual should be treated with ART. This recommendation was issued both for the patient’s own sake and for promoting treatment as prevention.

Text message intervention designs to promote adherence to antiretroviral therapy (ART): a meta-analysis of randomized controlled trials

BACKGROUND

The efficacy of antiretroviral therapy depends on patient adherence to a daily medication regimen, yet many patients fail to adhere at high enough rates to maintain health and reduce the risk of transmitting HIV. Given the explosive global growth of cellular-mobile phone use, text-messaging interventions to promote adherence are especially appropriate. This meta-analysis synthesized available text messaging interventions to promote antiretroviral therapy adherence in people living with HIV.

METHODS

We performed Boolean searches of electronic databases, hand searches of recent year conference abstracts and reverse searches. Included studies (1) targeted antiretroviral therapy adherence in a sample of people living with HIV, (2) used a randomized-controlled trial design to examine a text messaging intervention, and (3) reported at least one adherence measurement or clinical outcome.

RESULTS

Eight studies, including 9 interventions, met inclusion criteria. Text-messaging interventions yielded significantly higher adherence than control conditions (OR = 1.39; 95% CI = 1.18, 1.64). Sensitivity analyses of intervention characteristics suggested that studies had larger effects when interventions (1) were sent less frequently than daily, (2) supported bidirectional communication, (3) included personalized message content, and (4) were matched to participants' antiretroviral therapy dosing schedule. Interventions were also associated with improved viral load and/or CD4+ count (k = 3; OR = 1.56; 95% CI = 1.11, 2.20).

CONCLUSIONS

Text-messaging can support antiretroviral therapy adherence. Researchers should consider the adoption of less frequent messaging interventions with content and timing that is individually tailored and designed to evoke a reply from the recipient. Future research is needed in order to determine how best to optimize efficacy.

HIV-1 virologic failure and acquired drug resistance among first-line antiretroviral experienced adults at a rural HIV clinic in coastal Kenya: a cross-sectional study

Background

An increasing number of people on antiretroviral therapy (ART) in sub-Saharan Africa has led to declines in HIV related morbidity and mortality. However, virologic failure (VF) and acquired drug resistance (ADR) may negatively affect these gains. This study describes the prevalence and correlates of HIV-1 VF and ADR among first-line ART experienced adults at a rural HIV clinic in Coastal Kenya.

Methods

HIV-infected adults on first-line ART for ≥6 months were cross-sectionally recruited between November 2008 and March 2011. The primary outcome was VF, defined as a one-off plasma viral load of ≥400 copies/ml. The secondary outcome was ADR, defined as the presence of resistance associated mutations. Logistic regression and Fishers exact test were used to describe correlates of VF and ADR respectively.

Results

Of the 232 eligible participants on ART over a median duration of 13.9 months, 57 (24.6% [95% CI: 19.2 – 30.6]) had VF. Fifty-five viraemic samples were successfully amplified and sequenced. Of these, 29 (52.7% [95% CI: 38.8 – 66.3]) had at least one ADR, with 25 samples having dual-class resistance mutations. The most prevalent ADR mutations were the M184V (n = 24), K103N/S (n = 14) and Y181C/Y/I/V (n = 8). Twenty-six of the 55 successfully amplified viraemic samples (47.3%) did not have any detectable resistance mutation. Younger age (15–34 vs. ≥35 years: adjusted odd ratios [95% CI], p-value: 0.3 [0.1–0.6], p = 0.002) and unsatisfactory adherence (<95% vs. ≥95%: 3.0 [1.5–6.5], p = 0.003) were strong correlates of VF. Younger age, unsatisfactory adherence and high viral load were also strong correlates of ADR.

Conclusions

High levels of VF and ADR were observed in younger patients and those with unsatisfactory adherence. Youth-friendly ART initiatives and strengthened adherence support should be prioritized in this Coastal Kenyan setting. To prevent unnecessary/premature switches, targeted HIV drug resistance testing for patients with confirmed VF should be considered.

Reliability and clinical relevance of the HIV-1 drug resistance test in patients with low viremia levels

BACKGROUND

We evaluated reliability and clinical usefulness of genotypic resistance testing (GRT) in patients for whom combination antiretroviral therapy (cART) was unsuccessful with viremia levels 50-1000 copies/mL, for whom GRT is generally not recommended by current guidelines.

METHODS

The genotyping success rate was evaluated in 12 828 human immunodeficiency virus type 1 (HIV-1) plasma samples with viremia >50 copies/mL, tested using the commercial ViroSeq HIV-1 Genotyping System or a homemade system. Phylogenetic analysis was performed to test the reliability and reproducibility of the GRT at low-level viremia (LLV). Drug resistance was evaluated in 3895 samples from 2200 patients for whom treatment was unsuccessful (viremia >50 copies/mL) by considering the resistance mutations paneled in the 2013 International Antiviral Society list.

RESULTS

Overall, the success rate of amplification/sequencing was 96.4%. Viremia levels of 50-200 and 201-500 copies/mL afforded success rates of 67.2% and 88.1%, respectively, reaching 93.2% at 501-1000 copies/mL and ≥97.3% above 1000 copies/mL. A high homology among sequences belonging to the same subject for 96.4% of patients analyzed was found. The overall resistance prevalence was 74%. Drug resistance was commonly found also at LLV. In particular, by stratifying for different viremia ranges, detection of resistance was as follows: 50-200 copies/mL = 52.8%; 201-500 = 70%; 501-1000 = 74%; 1001-10 000 = 86.1%; 10 001-100 000 = 76.7%; and >100 000 = 63% (P < .001). Similar bell-shaped results were found when the GRT analysis was restricted to 2008-2012, although at a slightly lower prevalence.

CONCLUSIONS

In patients failing cART with LLV, HIV-1 genotyping provides reliable and reproducible results that are informative about emerging drug resistance.

Performance of HIV-1 drug resistance testing at low-level viremia and its ability to predict future virologic outcomes and viral evolution in treatment-naive individuals

BACKGROUND

Low-level viremia (LLV; human immunodeficiency virus [HIV-1] RNA 50-999 copies/mL) occurs frequently in patients receiving antiretroviral therapy (ART), but there are few or no data available demonstrating that HIV-1 drug resistance testing at a plasma viral load (pVL) <1000 copies/mL provides potentially clinically useful information. Here, we assess the ability to perform resistance testing by genotyping at LLV and whether it is predictive of future virologic outcomes in patients beginning ART.

METHODS

Resistance testing by genotyping at LLV was attempted on 4915 plasma samples from 2492 patients. A subset of previously ART-naive patients was analyzed who achieved undetectable pVL and subsequently rebounded with LLV (n = 212). A genotypic sensitivity score (GSS) was calculated based on therapy and resistance testing results by genotyping, and stratified according to number of active drugs.

RESULTS

Eighty-eight percent of LLV resistance assays produced useable sequences, with higher success at higher pVL. Overall, 16 of 212 (8%) patients had pretherapy resistance. Thirty-eight of 196 (19%) patients without pretherapy resistance evolved resistance to 1 or more drug classes, primarily the nucleoside reverse transcriptase (14%) and/or nonnucleoside reverse transcriptase (9%) inhibitors. Patients with resistance at LLV (GSS <3) had a 2.1-fold higher risk of virologic failure (95% confidence interval, 1.2- to 3.7-fold) than those without resistance (P = .007). Progressively lower GSS scores at LLV were associated with a higher increase in pVL over time (P < .001). Acquisition of additional resistance mutations to a new class of antiretroviral drugs during LLV was not found in a subset of patients.

CONCLUSIONS

Routine HIV-1 genotyping of LLV samples can be performed with a reasonably high success rate, and the results appear predictive of future virologic outcomes.

Post-treatment HIV-1 controllers with a long-term virological remission after the interruption of early initiated antiretroviral therapy ANRS VISCONTI Study

Combination antiretroviral therapy (cART) reduces HIV-associated morbidities and mortalities but cannot cure the infection. Given the difficulty of eradicating HIV-1, a functional cure for HIV-infected patients appears to be a more reachable short-term goal. We identified 14 HIV patients (post-treatment controllers [PTCs]) whose viremia remained controlled for several years after the interruption of prolonged cART initiated during the primary infection. Most PTCs lacked the protective HLA B alleles that are overrepresented in spontaneous HIV controllers (HICs); instead, they carried risk-associated HLA alleles that were largely absent among the HICs. Accordingly, the PTCs had poorer CD8+ T cell responses and more severe primary infections than the HICs did. Moreover, the incidence of viral control after the interruption of early antiretroviral therapy was higher among the PTCs than has been reported for spontaneous control. Off therapy, the PTCs were able to maintain and, in some cases, further reduce an extremely low viral reservoir. We found that long-lived HIV-infected CD4+ T cells contributed poorly to the total resting HIV reservoir in the PTCs because of a low rate of infection of naïve T cells and a skewed distribution of resting memory CD4+ T cell subsets. Our results show that early and prolonged cART may allow some individuals with a rather unfavorable background to achieve long-term infection control and may have important implications in the search for a functional HIV cure.

Characterization of HIV-1 antiretroviral drug resistance after second-line treatment failure in Mali, a limited-resources setting

OBJECTIVES

We describe the outcomes of second-line drug resistance profiles and predict the efficacy of drugs for third-line therapy in patients monitored without the benefit of plasma HIV-1 RNA viral load (VL) or resistance testing.

METHODS

We recruited 106 HIV-1-infected patients after second-line treatment failure in Mali. VL was determined by the Abbott RealTime system and the resistance by the ViroSeq HIV-1 genotyping system. The resistance testing was interpreted using the latest version of the Stanford algorithm.

RESULTS

Among the 106 patients, 93 had isolates successfully sequenced. The median age, VL and CD4 cells were respectively 35 years, 72 000 copies/mL and 146 cells/mm(3). Patients were exposed to a median of 4 years of treatment and to six antiretrovirals. We found 20% of wild-type viruses. Resistance to etravirine was noted in 38%, to lopinavir in 25% and to darunavir in 12%. The duration of prior nucleos(t)ide reverse transcriptase inhibitor exposure was associated with resistance to abacavir (P < 0.0001) and tenofovir (P = 0.0001), and duration of prior protease inhibitor treatment with resistance to lopinavir (P < 0.0001) and darunavir (P = 0.06).

CONCLUSION

Long duration of therapy prior to failure was associated with high levels of resistance and is directly related to limited access to VL monitoring and delayed switches to second-line treatment, precluding efficacy of drugs for third-line therapy. This study underlines the need for governments and public health organizations to recommend the use of VL monitoring and also the availability of darunavir and raltegravir for third-line therapies in the context of limited-resource settings.

Impact of low-level-viremia on HIV-1 drug-resistance evolution among antiretroviral treated-patients

BACKGROUND

Drug-resistance mutations (DRAM) are frequently selected in patients with virological failure defined as viral load (pVL) above 500 copies/ml (c/mL), but few resistance data are available at low-level viremia (LLV). Our objective was to determine the emergence and evolution of DRAM during LLV in HIV-1-infected patients while receiving antiretroviral therapy (ART).

METHODS

Retrospective analysis of patients presenting a LLV episode defined as pVL between 40 and 500 c/mL on at least 3 occasions during a 6-month period or longer while on the same ART. Resistance genotypic testing was performed at the onset and at the end of LLV period. Emerging DRAM was defined during LLV if never detected on baseline genotype or before.

RESULTS

48 patients including 4 naive and 44 pretreated (median 9 years) presented a LLV episode with a median duration of 11 months. Current ART included 2NRTI (94%), ritonavir-boosted PI (94%), NNRTI (23%), and/or raltegravir (19%). Median pVL during LLV was 134 c/mL. Successful resistance testing at both onset and end of the LLV episode were obtained for 37 patients (77%), among who 11 (30%) acquired at least 1 DRAM during the LLV period: for NRTI in 6, for NNRTI in 1, for PI in 4, and for raltegravir in 2. During the LLV period, number of drugs with genotypic resistance increased from a median of 4.5 to 6 drugs. Duration and pVL level of LLV episode, duration of previous ART, current and nadir CD4 count, number of baseline DRAM and GSS were not identified as predictive factors of resistance acquisition during LLV, probably due to limited number of patients.

CONCLUSION

Persistent LLV episodes below 500 c/ml while receiving ART is associated with emerging DRAM for all drug classes and a decreasing in further therapeutic options, suggesting to earlier consider resistance monitoring and ART optimization in this setting.

The global status of HIV drug resistance: clinical and public-health approaches for detection, treatment and prevention

Antiretroviral therapy (ART) scale-up in resource limited settings (RLS) has been successful, utilizing a standardized population-based approach to ART delivery. An unintended consequence of treatment scale-up is the inevitable emergence of HIV drug resistance (HIV DR) in populations even when patient adherence to ART is optimally supported. HIV DR has the potential to undermine the dramatic gains that ART has had in reducing the morbidity and mortality of HIV-infected patients in RLS. Sustaining and expanding ART coverage in RLS will depend upon the ability of ART programs to deliver ART in a way that minimizes the emergence of HIVDR. Fortunately, current evidence demonstrates that HIVDR in RLS has neither emerged nor been transmitted to the degree that had initially been feared. However, due to a lack of standardized methodologies, HIVDR data from RLS can be difficult to interpret and may not provide the programmatic evidence necessary for public health action. The World Health Organization has developed simple, standardized surveys that generate comparable results to assess acquired and transmitted HIVDR for routine public health implementation in RLS. These HIVDR surveys are designed to be implemented in conjunction with annual monitoring of program and site factors known to create situations favorable to the developments of HIV DR.