Antiretroviral Resistance Research Articles

Antiretroviral drug use and HIV drug resistance among young women in rural South Africa: HPTN 068

Antiretroviral drug use and HIV drug resistance among young women in rural South Africa: HPTN 068

HIV-1 Antiretroviral Resistance in Cuba, 2009-2014.

INTRODUCTION By the end of 2017, there were more than 28,000 individuals living with HIV in Cuba, over 80% receiving antiretroviral therapy, which dramatically reduces viral replication, improves immune status and decreases risk of transmission. These results could be jeopardized by emergence of HIV-1 drug resistance. In 2009, a test for HIV-1 genotypic resistance was introduced in routine clinical practice in Cuba. OBJECTIVE Investigate antiretroviral resistance and its relation to subtype distribution in HIV-1 treatment-naïve and previously treated patients in Cuba. METHODS Resistance and HIV-1 subtype distribution were determined in 342 antiretroviral treatment-naïve patients and 584 previously treated for HIV-1 whose blood specimens were sent to the Pedro Kourí Tropical Medicine Institute during 2009-2014. Transmitted drug resistance was determined using the Calibrated Population Resistance Tool v.6. Drug resistance analysis was conducted using the algorithm Rega v9.1.0. RESULTS Prevalence of transmitted drug resistance was 11.4%, and 41% of mutated viruses exhibited dual-class resistance to nucleoside reverse transcriptase inhibitor and non-nucleoside reverse transcriptase inhibitor. Overall, 84.9% of patients had ≥1 resistance mutation, 80% had ≥1 nucleoside reverse transcriptase inhibitor mutation, 71.4% had ≥1 non-nucleoside reverse transcriptase inhibitor mutation and 31.7% had ≥1 protease inhibitor mutation. K65R and K101E mutations were significantly more frequent in subtype C, L210W in CRF19_cpx, and M47V/I in CRF BGs (20, 23, 24). Full class resistance to nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors and multidrug resistance were detected in 21.2%, 32.4%, 8% and 4.1% of patients, respectively. Average percentage resistance to nucleoside reverse transcriptase inhibitor, protease inhibitor, full class resistance to nucleoside reverse transcriptase inhibitor, protease inhibitor and multidrug resistance increased in patients failing two or more regimens. Nevertheless, after 2011, a declining trend was observed in the frequency of multidrug resistance and full class resistance to nucleoside reverse transcriptase inhibitors and protease inhibitors. CONCLUSIONS Detected levels of transmitted drug resistance highlight the need for a national surveillance study in treatment-naïve patients. Resistance prevalence is high in previously treated patients but appears to be decreasing over time. The frequency of resistance mutations in recombinant forms of HIV in Cuba needs further study. KEYWORDS Antiretroviral therapy, highly active antiretroviral therapy, HIV, anti-HIV agents, drug resistance, multiple drug resistance, Cuba.

No Difference in Prevalence of Transmitted Drug Resistance between Injection Drug Users and Non-Injection Drug Users: A Cross-Sectional Study among Antiretroviral Treatment-Naïve HIV Patients

Objectives: The epidemiological evidence is inconsistent about whether HIV-positive injection drug users (IDUs) are at higher risk of developing antiretroviral resistance than any other HIV-positive populations. This study aims to investigate and compare transmitted drug resistance (TDR) between IDUs and non-IDUs in Lingshan County, an HIV-hit region in Guangxi, China, where IDU and heterosexual transmission were the two dominant transmission routes and roughly equally contributed to the local HIV transmission. Methods: A cross-sectional study was conducted among newly diagnosed and antiretroviral-treatment (ART)-naïve HIV-1 patients from Lingshan County. The pol gene of HIV-1 from the individuals was sequenced followed by genotyping and TDR analysis. Results: Two dominant transmission routes, heterosexual contact and IDU, accounted for 49.2 and 45.9% of 183 HIV-1 infection cases, respectively. Three genotypes, including CRF08_BC (70.6%), CRF01_AE (24.4%), and CRF07_BC (5.0%), and three unique recombinant forms (1.6%), were identified. There was a significant difference in genotype distribution among the different transmission routes (F = 21.814, p < 0.001). The overall TDR prevalence was 5.5%. There were no significant differences in TDR prevalence among the different transmission routes (F = 1.420, p = 0.439). Conclusions: Injection drug use has little impact on TDR prevalence compared with other routes of transmission.

Human Immunodeficiency Virus Antiretroviral Resistance and Transmission in Mother-Infant Pairs Enrolled in a Large Perinatal Study.

The presence of antiretroviral drug-associated resistance mutations (DRMs) may be particularly problematic in human immunodeficiency virus (HIV)-infected pregnant women as it can lead to mother-to-child transmission (MTCT) of resistant HIV strains. This study evaluated the prevalence and the effect of antiretroviral DRMs in previously untreated mother-infant pairs. A case-control design of 1:4 (1 transmitter to 4 nontransmitters) was utilized to evaluate DRMs as a predictor of HIV MTCT in specimens obtained from mother-infant pairs. ViroSeq HIV-1 genotyping was performed on mother-infant specimens to assess for clinically relevant DRMs. One hundred forty infants acquired HIV infection; of these, 123 mother-infant pairs (88%) had specimens successfully amplified using ViroSeq and assessed for drug resistance genotyping. Additionally, 483 of 560 (86%) women who did not transmit HIV to infants also had samples evaluated for DRMs. Sixty-three of 606 (10%) women had clinically relevant DRMs; 12 (2%) had DRMs against >1 drug class. Among 123 HIV-infected infants, 13 (11%) had clinically relevant DRMs, with 3 (2%) harboring DRMs against >1 drug class. In univariate and multivariate analyses, DRMs in mothers were not associated with increased HIV MTCT (adjusted odds ratio, 0.8 [95% confidence interval, .4-1.5]). Presence of DRMs in transmitting mothers was strongly associated with DRM presence in their infants (P < .001). Preexisting DRMs were common in untreated HIV-infected pregnant women, but did not increase the risk of HIV MTCT. However, if women with DRMs are not virologically suppressed, they may transmit resistant mutations, thus complicating infant management.

Characterization of HIV-1 Near Full-Length Proviral Genome Quasispecies from Patients with Undetectable Viral Load Undergoing First-Line HAART Therapy.

Increased access to highly active antiretroviral therapy (HAART) by human immunodeficiency virus postive (HIV+) individuals has become a reality worldwide. In Brazil, HAART currently reaches over half of HIV-infected subjects. In the context of a remarkable HIV-1 genetic variability, highly related variants, called quasispecies, are generated. HIV quasispecies generated during infection can influence virus persistence and pathogenicity, representing a challenge to treatment. However, the clinical relevance of minority quasispecies is still uncertain. In this study, we have determined the archived proviral sequences, viral subtype and drug resistance mutations from a cohort of HIV+ patients with undetectable viral load undergoing HAART as first-line therapy using next-generation sequencing for near full-length virus genome (NFLG) assembly. HIV-1 consensus sequences representing NFLG were obtained for eleven patients, while for another twelve varying genome coverage rates were obtained. Phylogenetic analysis showed the predominance of subtype B (83%; 19/23). Considering the minority variants, 18 patients carried archived virus harboring at least one mutation conferring antiretroviral resistance; for six patients, the mutations correlated with the current ARVs used. These data highlight the importance of monitoring HIV minority drug resistant variants and their clinical impact, to guide future regimen switches and improve HIV treatment success.

High Prevalence of Drug Resistance Mutations Among Patients Failing First-Line Antiretroviral Therapy and Predictors of Virological Response 24 Weeks After Switch to Second-Line Therapy in São Paulo State, Brazil

Universal antiretroviral treatment with sustained viral suppression benefits patients and reduces HIV transmission. Effectiveness of therapy may be limited by antiretroviral drug resistance. Information on the resistance profile at treatment failure and its impact on antiretroviral drugs may subsidize subsequent treatment strategies. Partial pol sequences from 319 patients failing first-line therapy were analyzed for resistance associated mutations (RAMs) and HIV subtype. Demographic data, CD4 T cell count, viral load, and antiretroviral regimens and mutational profile at first-line failure were also investigated for associations to the response to second-line regimens. RAMs at the reverse transcriptase gene were frequent. Most sequences (88%) showed at least one mutation. A higher number of reverse transcriptase RAMs were associated to lower CD4 T cell counts and the use of tenofovir/lamivudine in first line. Among 205 with follow-up data, 76.6% were virally suppressed (below 200 copies/ml) after 24 weeks of second-line therapy. Most cases initiated second line with a regimen genotypic susceptibility score ≥2, but it did not predict viral suppression, that was independently associated with higher CD4 T cell counts and with the presence of nucleos(t)ide analog reverse transcriptase inhibitor (NRTI) RAMs. This study documented extensive resistance at first-line failure in this area in Brazil, highlights the risks of low CD4 T cell counts to second-line therapy, and supports the notion that recycled NRTIs may contribute to viral suppression even when genotypic resistance is present.

Virological response, HIV-1 drug resistance mutations and genetic diversity among patients on first-line antiretroviral therapy in N\u2019Djamena, Chad: findings from a cross-sectional study

BackgroundThe national antiretroviral therapy in the Republic of Chad provides free of charge antiretroviral regimens and therapeutic monitoring for patients receiving antiretroviral therapy nationwide. For a successful programmatic uptake, these efforts merit to be supported by thorough assessments of antiretroviral therapy response and HIV-1 drug resistance surveillance, especially with risks of cross-resistance due to the gradual stavudine phasing out in such national settings. We therefore evaluated the virological response to antiretroviral therapy, HIV-1 drug resistance emergence and circulating HIV-1 clades in a Chad context. A cross-sectional and prospective study was conducted among 116 patients (41 [δ ± 6.87] years, 59% female) receiving first-line antiretroviral therapy for ≥ 6 months in Ndjamena, Chad, in 2011–2012, enrolled consecutively. To ensure accuracy, plasma viral load was concomitantly measured using Abbott Real-Time and Cobas AmpliPrep/TaqMan (v2.0), and virological failure defined as ≥ 1000 HIV-1 RNA copies/ml. Plasma from patients experiencing virological failure were processed for sequencing of HIV-1 protease-reverse transcriptase using the ANRS-AC.11 resistance testing protocol; drug resistant mutations were interpreted using the ANRS-AC11 algorithm; and phylogenetic analysis was performed using MEGA.v.6.ResultsMajority of patients was receiving zidovudine plus lamivudine plus nevirapine (46%), stavudine plus lamivudine plus nevirapine (41%) and tenofovir plus emtricitabine plus efavirenz (11%), for a median time-on-treatment of 5 [IQR 4–7] years. The rate of virological failure was 43% (50/116), with 86% (43/50) sequencing performance. Overall, 32% (37/116) patients presented ≥ one major drug resistant mutation(s), with 29% (34/116) to nucleos(t)ide reverse transcriptase inhibitors (67% [29/43] M184V/I, 30% [13/43] T215Y/F, 19% [8/43] V75A/F/I/L/M, 9% [4/43] K70P/R/W, 9% [4/43] K219E/N/Q and 5% [2/43] A62V); 86% (37/43) to non-nulceos(t)ide reverse transcriptase inhibitors (30% [13/43] K103N/S/E, 26% [11/43] Y181C/V/F/L, 2% [1/43] L100I, 2% [1/43] F227L, 2% [1/43] P225H); and 2% (1/43) to protease inhibitors (M46I, I54V, V82S). Six HIV-1 subtypes were found: 30% circulating recombinant form (CRF02_AG), 30% J, 16% G, 9% A, 9% D, 5% F.ConclusionsIn Chad, almost half of patients are failing first-line antiretroviral therapy after 5 years, with considerable drug resistant mutations at failure. Absence of K65R supports the use of tenofovir-containing regimens as preferred first-line and as suitable drug for second-line combinations, in this setting with significant HIV-1 genetic diversity.

Correction to: HIV-1 genetic diversity, geographical linkages and antiretroviral drug resistance among individuals from Pakistan.

Unfortunately, the co-author's name Nouman Mughal was incorrectly published in the original article and the same is corrected here in this erratum.

Upward trends of acquired drug resistances in Ethiopian HIV-1C isolates: A decade longitudinal study.

BackgroundThe emergence, accumulation and spread of HIV-1 drug resistance strains in Africa could compromise the effectiveness of HIV treatment programs. This study was aimed at determining the incidence of virological failure and acquired drug resistance mutations overtime and identifying the most common mutational pathways of resistance in a well characterized HIV-1C infected Ethiopian cohort.MethodsA total of 320 patients (220 ART naïve and 100 on first lines ART) were included and followed. ART initiation and patients’ monitoring was based on the WHO clinical and immunological parameters. HIV viral load measurement and genotypic drug resistance testing were done at baseline (T0-2008) and after on average at a median time of 30 months on ART at three time points (T1-2011, T2-2013, T3-2015).FindingsThe incidence of virological failure has increased overtime from 11 at T1 to 17 at T2 and then to 30% at T3. At all time point’s almost all of the patients with virological failure and accumulated drug resistance mutations had not met the WHO clinical and immunologic failure criteria and continued the failing regimen. A steep increase in the incidence and accumulation of major acquired NRTI and NNRTI drug resistance mutations have been observed (from 40% at T1 to 64% at T2 and then to 66% at T3). The most frequent NRTIs drug resistance associated mutations are mainly the lamivudine-induced mutation M184V which was detected in 4 patients at T1 and showed a 2 fold increase in the following time points (T2: n = 8) and at (T3: n = 12) and the thymidine analogue mutations (such as D67N, K70R and K219E) which were not-detected at baseline T0 and T1 but were increased progressively to 10 at T2 and to 17 at T3. The most frequent NNRTIs associated mutations were K103N, V106M and Y188C.ConclusionsAn upward trend in the incidence of virological failure and accumulation of NRTI and NNRTI associated acquired antiretroviral drug resistance mutations are observed. The data suggest the need for virological monitoring, resistance testing for early detection of failure and access for TDF and PI containing drugs. Population-level and patient targeted interventions to prevent the spread of mutant variants is warranted.

Comparison of antiretroviral drug resistance among treatment-naive and treated HIV-infected individuals in Shiraz, Iran.

The use of anti-retroviral therapy has been effective in controlling the spread of HIV-1, and has prolonged life expectancy, but this success can be affected by the emergence of drug resistance. The main goal of this study was to investigate drug resistance in the reverse transcriptase (RT), and protease (PR) genes among HIV-1 infected individuals. We systematically selected 59 HIV-1 infected individuals from Shiraz Voluntary Counseling and Testing Center (29 treatment- naïve and 30 treated). In this study intravenous drug users older than 18 were included in this study. Using specific primers, nested RT-PCR was performed on RNA extracted from patient samples. The genes targeted for RT and PCR were successfully amplified and sequenced. The sequences of these two genes were compared with mutations related to drug resistance against nucleotide reverse transcriptase inhibitors (NRTI), non-nucleotide reverse transcriptase inhibitors (NNRTI) and protease inhibitors (PI) using the latest database from the International AIDS society - USA, Stanford University, and the patterns were recorded. Among treatment-naïve, the detected NRTI and NNRTI resistance mutations were V179T, V75M and E138A. V179T causes high level resistance to Efavirenze and Nevirapin. V75M causes intermediate resistance to Stavudine. Regarding NRTI and NNRTI resistance mutations among treated patients, the most frequent mutation (7%) was M184V, which causes high level resistance to zidovudin and emtricitabine. The interesting result from this study was the detection of NRTI and NNRTI resistance mutations before the initiation of treatment, which signifies the transmission of resistant strains of virus between individuals. This mutation highlights the importance of drug resistance HIV-1 genotyping before commencing treatment.

Alternative Sample Types for HIV-1 Antiretroviral Drug Resistance Testing.

Monitoring human immunodeficiency virus type 1 (HIV-1) drug resistance is critical for assessing ART effectiveness and treatment outcomes for HIV-1-infected individuals, including children, worldwide. Traditionally, testing for HIV-1 drug resistance has primarily been performed on plasma samples, and with commercially available, clinically validated assays that are costly and difficult to access. While plasma is the preferred sample for HIV-1 drug resistance genotyping, plasma analysis requires sophisticated laboratory equipment, personnel, space, and stringent storage conditions for maintenance of sample integrity and transport. With the limitations in feasibility and affordability of providing these ideal conditions for plasma genotyping in resource-constrained settings, the field has gained substantial experience with the dried blood spot (DBS) technique as an alternative. Moreover, DBS analysis can be used to comprehensively monitor the spread of the epidemic with applications to more-sensitive and quantitative technologies to assess HIV-1 globally.

HIV Antiretroviral Resistance and Transmission in Mother–Infant Pairs Enrolled in a Large Perinatal Study

BackgroundDetection of antiretroviral (ARV) resistance in HIV-infected individuals is not uncommon and may be particularly problematic in HIV-infected pregnant women as it can lead to infant infection with resistant strains. To better evaluate the effect of drug resistance mutations (DRMs) on HIV mother-to-child transmission (MTCT), we determined the prevalence of DRMs in a subset of mother–infant pairs enrolled in a multi-center trial of infant prophylaxis among women not receiving ARVs during the current pregnancy.MethodsA case–control design of 1:4 (1 transmitter to 4 nontransmitters) was utilized to evaluate ARV resistance as a predictor of HIV MTCT in specimens obtained from mother–infant pairs. Secondary objectives included identification of potential risk factors associated with the presence of DRMs. Viroseq HIV-1 Genotyping System was performed on mother–infant specimens to assess for mutations that might result in a substantial reduction in drug susceptibility and clinical outcome, as determined by the Stanford HIV Drug Resistance Database.ResultsOne hundred and forty infants were infected. Of these, 123 HIV infected mother–infant pairs and 483 of 560 women who did not transmit HIV had amplifiable HIV nucleic acid enabling ARV resistance testing. A wide variety of DRMs were detected (Figure 1). Sixty (10%) of 606 women had clinically relevant DRMs; 12 (2%) had DRMs against more than 1 ARV class. Among 123 HIV− infected infants, 13 (11%) had clinically relevant DRMs with 3 (2%) harboring DRMs against more than 1 ARV class. Of 13 infants with DRMs, 10 (77%) were infected in utero. In univariate and multivariate analyses, DRMs in mothers were not associated with increased risk of HIV MTCT (AOR 0.79, 95% CI 0.38–1.5). Log HIV viral load was the only predictor of MTCT (OR 1.4, 95% CI 1.2−1.6). The presence of DRMs in mothers who transmitted was strongly associated with the presence of DRMs in infants (P < 0.001).ConclusionIn infected pregnant women without ARV exposure during their current gestation, the presence of pre-existing DRMs with a wide diversity was noted. DRMs do not increase the risk of HIV MTCT. However, if women with DRMs are not virologically suppressed they are likely to transmit resistant mutations even without selective ARV pressure, thus complicating treatment options.Disclosures All authors: No reported disclosures.

Transmitted Drug Resistance in Treatment-naïve HIV-Infected VCT clients in Taiwan, 2007–2016

BackgroundThe transmission of drug-resistant HIV-1 strains might compromise the efficacy of antiretroviral treatment. The aim of this study was to monitor the prevalence of transmitted drug resistance (TDR) in Taiwan, where free highly active antiretroviral therapy (HAART) was provided since 1997.MethodsA cohort study on TDR was conducted in antiretroviral therapy -naïve HIV-1 ¡Vinfected voluntary counseling and testing (VCT) clients from 2007 to 2016 in southern Taiwan. Genotypic drug resistance testing to PR/RT (pol gene) were determined by ViroSeqTM system and drug resistance testing to integrase inhibitors (INSTI) was done by in house PCR. Antiretroviral resistance was interpreted using the HIVdb program of the Stanford University HIV Drug Resistance Database. The patients classified as having low-level resistance, intermediate resistance and high-level resistance were defined as having drug resistance. Resistance-associated mutations were defined by the presence of at least one mutation included in the 2017 drug resistance mutation list of the International AIDS Society-USA consensus guidelines.ResultsA total of 29384 individuals received a free HIV anonymously screening test during 2007 to 2016. The positive rate for HIV-1 infection was 2%. Sequences were obtained from 407 individuals, of whom 90% were infected by MSM, and 10% were infected by heterosexually. Subtype B HIV-1 strains were found in 97%, subtype C in 0.3% and subtype CRF01_AE in 2.7%. A total of 6% was found to harbor drug resistance strains. The most common NRTI resistance associated mutation was D67N, M184V, K219N, Y118I and T215S/P. The most common NNRTI resistance associated mutation was Y181C, K103N, V179D and Y318F. No any one harbored resistance to INSTI inhibitors (n = 188).ConclusionThe resistance prevalence (6%) in this study supported the WHO guideline to prescribe pol resistance testing before initiation of HAART therapy in the treatment naïve patients.Disclosures All authors: No reported disclosures.

HIV-1 genetic diversity, geographical linkages and antiretroviral drug resistance among individuals from Pakistan.

Worldwide antiretroviral therapy (ART) has reduced the mortality and morbidity rates in individuals with HIV infection. However, the increasing occurrence of drug resistance is limiting treatment options. In recent years, Pakistan has witnessed a concentrated epidemic of HIV. It is very important to identify geographical linkages and mutations that generate selective pressure and drive resistance of HIV in our population. The aim of this work was to identify genetic diversity and drug resistance patterns of HIV in Pakistan, using available sequences and bioinformatics tools, which may help in selecting effective combination of available drugs. A total of 755 Pakistani HIV gag, pol and env sequences were retrieved from the Los Alamos HIV database. Sequences were aligned with reference sequences of different subtypes. For geographical linkages, sequences of predominant subtypes were aligned with sequences of the same subtypes from different countries. Phylogenetic trees were constructed using the maximum-likelihood method in MEGA 7 software. For drug resistance analysis, sequences were entered into the Stanford University HIV Drug Resistance Database. Phylogenetic trees for studying genetic diversity showed that 82% of the sequences were of subtype A, while the rest of the sequences were of subtypes B (9.5%), K (2%), D (2%) and AE (1%). Moreover, trees that were constructed to examine geographical linkages showed close clustering of strains with those of the neighboring countries Afghanistan and India, as well as some African countries. A search for drug resistance mutations showed that 93% of the sequences had no major or minor mutations. The remaining 7% of the sequences contained a major mutation, Y115F, which causes the virus to exhibit low to intermediate resistance against lamivudine and emtricitabine. Our data indicate that HIV subtype A is the major subtype, while subtypes K, D and AE are also present in our country, suggesting gradual viral evolution and possible entry of different subtypes from neighboring countries. These data suggest that HIV is still sensitive to most of the antiretroviral drugs used in Pakistan.

Prevalence and trends in transmitted and acquired antiretroviral drug resistance, Washington, DC, 1999\u20132014

BackgroundDrug resistance limits options for antiretroviral therapy (ART) and results in poorer health outcomes among HIV-infected persons. We sought to characterize resistance patterns and to identify predictors of resistance in Washington, DC.MethodsWe analyzed resistance in the DC Cohort, a longitudinal study of HIV-infected persons in care in Washington, DC. We measured cumulative drug resistance (CDR) among participants with any genotype between 1999 and 2014 (n = 3411), transmitted drug resistance (TDR) in ART-naïve persons (n = 1503), and acquired drug resistance (ADR) in persons with genotypes before and after ART initiation (n = 309). Using logistic regression, we assessed associations between patient characteristics and transmitted resistance to any antiretroviral.ResultsPrevalence of TDR was 20.5%, of ADR 40.5%, and of CDR 45.1% in the respective analysis groups. From 2004 to 2013, TDR prevalence decreased for nucleoside and nucleotide analogue reverse transcriptase inhibitors (15.0 to 5.5%; p = 0.0003) and increased for integrase strand transfer inhibitors (INSTIs) (0.0–1.4%; p = 0.04). In multivariable analysis, TDR was not associated with age, race/ethnicity, HIV risk group, or years from HIV diagnosis.ConclusionsIn this urban cohort of HIV-infected persons, almost half of participants tested had evidence of CDR; and resistance to INSTIs was increasing. If this trend continues, inclusion of the integrase-encoding region in baseline genotype testing should be strongly considered.

Hepatitis B virus DNA polymerase gene polymorphism based prediction of genotypes in chronic HBV patients from Western India.

Hepatitis B Virus (HBV) infection is one of the major causes of liver cirrhosis, hepatocellular carcinoma and deaths due to the acute or chronic consequences worldwide. HBV is distributed into various genotypes based on nucleic acid sequence variation. To develop a method of HBV genotyping and drug resistance interpretation using partial sequencing of polymerase gene. This study was performed on 98 HBV infected patients' serum samples from Western India. A nested PCR protocol was designed for amplification of pol gene from HBV genome and Sanger's sequencing of the gene fragment. Sequences were aligned with HBV reference sequences for phylogenetic analysis and for characterization of genetic diversity. Drug resistance mutations were screened using HBVSeq program from Stanford University. Distribution of HBV genotypes showed predominance of genotype D, circulating in 76 (77.55%) patients (p < 0.05). Genotypes A and C were less prevalent and were identified in 4 (4.08%) and 18 (18.37%) patients, respectively. Anti-retroviral drug resistance mutations were not detected in any patient. A method for determination of HBV genotypes using pol gene sequencing which simultaneously detects major drug resistance mutations has been established. HBV genetic diversity may play an important role in treatment decision.

Antiretroviral resistance following immunological monitoring in a resource-limited setting of western India: A cross-sectional study.

BackgroundThe free antiretroviral therapy (ART) program in India still relies on the clinico-immunological monitoring for diagnosis of treatment failure. As the nucleoside reverse transcriptase inhibitor (NRTI) backbone is shared in first- and second-line regimens, accumulation of drug resistant mutations (DRMs) can compromise the efficacy of NRTI. This study was undertaken to describe the pattern of HIV DRMs following immunological monitoring and investigate its impact on the cycling of NRTI between first- and second-line ART.Methods and findingsThis cross-sectional study was performed at a state-sponsored ART clinic of Pune city in western India between January and June 2016. Consecutive adults receiving first-line ART with immunological failure (IF) were recruited for plasma viral load (PVL) estimation. Randomly selected 80 participants with PVL >1000 copies/mL underwent HIV drug resistance genotyping. Of these, 75 plasma sample were successfully genotyped. The median CD4 count and duration of ART at the time of failure were 98 (IQR: 61.60–153.50) cells/μL and 4.62 (IQR: 3.17–6.15) years, respectively. The prevalence of NRTI, non-NRTI, and major protease inhibitor resistance mutations were 89.30%, 96%, and 1.33%, respectively. Following first-line failure, sequences from 56.67% of individuals indicated low- to high-level resistance to all available NRTI. The proportion of sequences with ≥2 thymidine analogue mutations (TAMs) and ≥3 TAMs were 62.12% and 39.39%, respectively. An average of 1.98 TAMs per sequence were observed following IF as compared to 0.37 TAMs per sequence following targeted PVL monitoring at 12 months of ART from a prior study; this difference was significant (p<0.001).ConclusionThe option of cycling of NRTI analogues between first- and second-line regimens would no longer be effective if individuals are followed-up by immunological monitoring due to accumulation of mutations. Introduction of routine PVL monitoring is a priority for the long-term sustainability of free ART program in India.

Antiretroviral resistance testing in people living with HIV

Antiretroviral resistance testing in people living with HIV

HIV-1 genetic diversity and primary drug resistance mutations before large-scale access to antiretroviral therapy, Republic of Congo

BackgroundIn this work, we investigated the genetic diversity of HIV-1 and the presence of mutations conferring antiretroviral drug resistance in 50 drug-naïve infected persons in the Republic of Congo (RoC). Samples were obtained before large-scale access to HAART in 2002 and 2004.MethodsTo assess the HIV-1 genetic recombination, the sequencing of the pol gene encoding a protease and partial reverse transcriptase was performed and analyzed with updated references, including newly characterized CRFs. The assessment of drug resistance was conducted according to the WHO protocol.ResultsAmong the 50 samples analyzed for the pol gene, 50% were classified as intersubtype recombinants, charring complex structures inside the pol fragment. Five samples could not be classified (noted U). The most prevalent subtypes were G with 10 isolates and D with 11 isolates. One isolate of A, J, H, CRF05, CRF18 and CRF37 were also found. Two samples (4%) harboring the mutations M230L and Y181C associated with the TAMs M41L and T215Y, respectively, were found.ConclusionThis first study in the RoC, based on WHO classification, shows that the threshold of transmitted drug resistance before large-scale access to antiretroviral therapy is 4%.

Divergent HIV-1 strains (CRF92_C2U and CRF93_cpx) co-circulating in the Democratic Republic of the Congo: Phylogenetic insights on the early evolutionary history of subtype C.

Molecular epidemiological studies revealed that the epicenter of the HIV pandemic was Kinshasa, the capital city of the Democratic Republic of the Congo (DRC) in Central Africa. All known subtypes and numerous complex recombinant strains co-circulate in the DRC. Moreover, high intra-subtype diversity has been also documented. During two previous surveys on HIV-1 antiretroviral drug resistance in the DRC, we identified two divergent subtype C lineages in the protease and partial reverse transcriptase gene regions. We sequenced eight near full-length genomes and classified them using bootscanning and likelihood-based phylogenetic analyses. Four strains are more closely related to subtype C although within the range of inter sub-subtype distances. However, these strains also have small unclassified fragments and thus were named CRF92_C2U. Another strain is a unique recombinant of CRF92_C2U with an additional small unclassified fragment and a small divergent subtype A fragment. The three remaining strains represent a complex mosaic named CRF93_cpx. CRF93_cpx have two fragments of divergent subtype C sequences, which are not conventional subtype C nor the above described C2, and multiple divergent subtype A-like fragments. We then inferred the time-scaled evolutionary history of subtype C following a Bayesian approach and a partitioned analysis using major genomic regions. CRF92_C2U and CRF93_cpx had the most recent common ancestor with conventional subtype C around 1932 and 1928, respectively. A Bayesian demographic reconstruction corroborated that the subtype C transition to a faster phase of exponential growth occurred during the 1950s. Our analysis showed considerable differences between the newly discovered early-divergent strains and the conventional subtype C and therefore suggested that this virus has been diverging in humans for several decades before the HIV/M diversity boom in the 1950s.