Prevalence and associated factors for HIV-1 transmitted drug resistance in voluntary clients for counseling and testing in Southern Taiwan

Trend of HIV Transmitted Drug Resistance After the Introduction of Single-Tablet Regimens in Southern Taiwan

Background

The prevalence of transmitted drug resistance (TDR) after the universal implementation of STRs is unknown in Taiwan.

Objective

This study aimed to investigate the prevalence of TDR in patients with HIV-1 infection, clarify the risk factors for pol resistance, and compare differences in HIV drug resistance before and after the implementation of STRs in Taiwan.

Methods

Adult patients infected with HIV-1 were enrolled in this study from 2013 to 2021. Mutations associated with drug resistance were identified using the 2019 International Antiviral Society-USA list of drug resistant mutations in HIV, and drug susceptibility was assessed according to the Stanford HIV Drug Resistance Database edition 9. A logistic regression model was used to analyze the risk factors for pol resistance, and the differences in the prevalence of drug resistance from 2013-2016 to 2017-2021 were compared using the Mann-Whitney U-test. General linear regression was used to analyze temporal changes in the annual proportion of TDR overall and by type of antiretroviral drugs.

Results

A total of 369 patients were included. The prevalence rate of pol resistance was 9.8% (36/369). The resistance rates to nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), and integrase strand transfer inhibitors (INSTIs) were 3.3%, 6.9%, 0% and 1.8%, respectively. The patients with hepatitis C infection were more likely to have pol resistance (aHR 5.767, CI 1.232-26.991, p=0.026). The prevalence rate of pol resistance did not decrease after the implementation of STRs as first-line therapy in 2017 (11.2% vs 8.7%, aHR 1.329, CI 0.667-2.645, p=0.480), and no significant temporal changes were shown in the annual proportion of TDR overall or by type of antiretroviral drug.

Conclusion

Our findings showed a stable prevalence rate of transmitted drug resistance despite the implementation of STRs as the first-line therapy in June 2016.

High prevalence of HIV-1 transmitted drug resistance and factors associated with time to virological failure and viral suppression in Taiwan

BACKGROUND

Integrase strand transfer inhibitor (InSTI)-based regimens have become the major first-line treatment for HIV-1-infected patients in Taiwan. Transmitted drug resistance (TDR) and several clinical characteristics are associated with time to virological failure or viral suppression; however, these have not been investigated in Taiwan.

OBJECTIVES

To determine the impact of several factors on treatment outcomes in HIV-1-infected patients in Taiwan.

METHODS

The cohort included 164 HIV-1 treatment-naive patients in Taiwan from 2018 to 2020. Blood specimens were collected to determine the genotypic drug resistance using the Stanford University HIV drug resistance database. Cox proportional hazards models were used to identify factors associated with time to virological failure or viral suppression.

RESULTS

The prevalence of TDR in Taiwan was 27.4% and an increasing trend was seen from 2018 to 2020. TDR mutations related to NNRTIs were the most prevalent (21%) while TDR to InSTIs remained at a relatively low level (1.3%). A baseline HIV-1 viral load of ≥100 000 copies/mL was associated with a shorter time to virological failure [multivariate hazard ratio (mHR) 7.84; P = 0.018] and longer time to viral suppression (mHR 0.46; P < 0.001). Time to viral suppression was shorter in patients receiving InSTI-based regimens (mHR 2.18; P = 0.006). Different InSTI-based regimens as initial treatment did not affect the treatment outcomes.

CONCLUSIONS

This study found an increasing trend of HIV-1 TDR prevalence from 2018 to 2020 in Taiwan. Baseline HIV-1 viral load and receiving InSTI-based regimens are important factors associated with time to virological failure or viral suppression.

HIV-1 transmitted drug resistance in Brighton, UK, from 2014 to 2020

HIV-1 transmitted drug resistance (TDR) is associated with transmission in men who have sex with men (MSM), non MSM clusters, sexually transmitted infections (STIs) and can lead to antiretroviral failure. UK guidelines recommend performing TDR testing in all newly-diagnosed people living with HIV. We audited performance of TDR in our large tertiary HIV department from 2014-2020. All new patients had TDR testing attempted in the study period. The rate of TDR was 8% and was associated with increasing age and having non-B subtype. Having non-B subtype was not associated with being non-UK born. Thirty-four percent of people were diagnosed with a bacterial STI at the time of HIV diagnosis, but STI diagnosis was not associated with TDR. There was no significant change in TDR over the 6-year audit period. TDR remains a small but significant problem. Identifying these populations and providing effective HIV prevention interventions will reduce HIV incidence and TDR.

HIV-1 subtype variability and transmitted drug resistance in a culturally diverse population in Western Sydney, New South Wales, Australia

Background Transmitted human immunodeficiency virus type 1 (HIV-1) drug resistance (TDR) is an important contributor to antiretroviral treatment failure, and is associated with HIV-1 transmission among men who have sex with men (MSM), non-MSM clusters and individuals diagnosed with concurrent sexually transmissible infections (STI). Western Sydney has a culturally diverse population, with a high proportion of non-Australian-born individuals. This study describes the prevalence of TDR and non-B HIV-1 subtypes in a clinic-based population.

METHODS

A clinic database was examined for all newly diagnosed treatment-naïve HIV-1 patients and information on their HIV-1 resistance and subtype, demographics including country of birth and diagnosis of a bacterial sexually transmissible infection was collected.

RESULTS

Data were available from 74/79 individuals (62 cis-male, 16 cis-female and 1 transgender woman). Of the 74 genotypes, the prevalence of non-B subtypes and TDR was 43/74 (58%; 95%CI = 46.9-69.3) and 14/74 (19%; 95%CI = 10.0 to 27.8). It was also found that 30/79 (38%) had a concurrent bacterial STI. TDR was associated with subtype B infection (OR 3.53; 95%CI = 1.41-8.82; P = 0.007) and being born in Australia (OR 12.0; 95%CI = 2.45-58.86; P = 0.002).

CONCLUSION

The relative prevalence of non-B HIV-1 subtypes and TDR is higher in Western Sydney than in the rest of Australia. TDR is associated with subtype B HIV-1 and being Australian born, suggesting ongoing local transmission. This highlights the diversity of the HIV epidemic locally and the need for interventions to prevent ongoing HIV transmission.

Low prevalence of transmitted HIV-1 drug resistance detected by a dried blood spot (DBS)-based next-generation sequencing (NGS) method in newly diagnosed individuals in Cameroon in the years 2015-16

Objectives

To determine the most recent prevalence, transmission patterns and risk factors of transmitted drug-resistance mutations (TDRMs) in Cameroon, we initiated a multicentre study monitoring HIV-1 drug resistance in newly HIV-1-diagnosed individuals using a novel next-generation sequencing (NGS) assay applicable to fingerprick dried blood spot (DBS) samples.

Methods

Fingerprick DBS samples and questionnaires were collected from 360 newly HIV-1-diagnosed individuals in four hospitals in urban areas in Cameroon in the years 2015-16. We developed an HIV-1 protease and reverse transcriptase drug resistance genotyping assay applicable to DBS samples and HIV-1 genomes of groups M, N and O. The WHO 2009 list of mutations for surveillance of transmitted drug-resistant HIV strains was used to analyse TDRMs.

Results

Applying our 'DBS-NGS-genotypic resistance test', baseline HIV-1 drug resistance data were successfully obtained from 82.8% (298/360) of newly diagnosed individuals. At nucleotide frequencies >15%, TDRMs to NRTIs were observed in 3.0% (9/298), to NNRTIs in 4.0% (12/298) and to PIs in 1.3% (3/240). The NNRTI mutation K103N was most commonly detected (2.7%). Expanding the analysis to low-abundance TDRMs, i.e. 3%-15%, 12 additional individuals (4.0%) harbouring TDRMs were identified. Having unprotected sex with a known HIV-1-positive person was significantly associated with the transmission of DRMs (adjusted OR 9.6; 95% CI 1.79-51.3).

Conclusions

The prevalence of transmitted HIV-1 drug resistance is currently low in the study sites in Cameroon. Evidence of some risky sexual behaviours depicts a public health problem with possible implications for the prevention of new HIV-1 infections.

Trend of HIV transmitted drug resistance before and after implementation of HAART regimen restriction in the treatment of HIV-1 infected patients in southern Taiwan

Background

The use of fixed combination antiretroviral therapy with a low genetic barrier for the treatment of patients infected with human immunodeficiency virus (HIV) may affect the local HIV transmitted drug resistance (TDR) pattern. The present study aimed to investigate changes in the prevalence of HIV TDR following the implementation of a fixed regimen of HIV treatment in Taiwan in 2012.

Methods

TDR was measured in antiretroviral treatment-naïve HIV-1-infected individuals who participated in voluntary counseling and testing between 2007 and 2015 in southern Taiwan. Antiretroviral resistance mutations were interpreted using the HIVdb program from the Stanford University HIV Drug Resistance Database.

Results

Sequences were obtained from 377 consecutive individuals between 2007 and 2015. The overall prevalence rates of TDR HIV among the study population from 2007 to 2011 and 2012–2015 were 10.6 and 7.9%, respectively. Among the detected mutations, K103 N and V179D + K103R were more frequently observed after 2012. Four HIV-infected patients with K103 N variants were detected after 2012, and 4 of the 5 patients with V179D + K103R variants were found after 2012. No significant differences were observed in the TDRs among nucleoside reverse transcriptase inhibitors (NRTIs), non-NRTIs (NNRTIs), protease inhibitors, multiple drug resistance, and any drug resistance between period 1 (2007–2011) and period 2 (2012–2015).

Conclusions

A fixed treatment regimen with zidovudine/lamivudine + efavirenz or nevirapine as first-line therapy for treatment-naïve patients infected with HIV did not significantly increase the TDR during the 4-year follow-up period. Due to the increase in NNRTI resistance associated with mutations after 2012, a longer follow-up period and larger sample size are needed in future studies.

HIV-1 genotypic drug resistance in patients with virological failure to single-tablet antiretroviral regimens in southern Taiwan

Purpose

Sparse data are available on the prevalence of resistance among HIV-1-infected patients with virological failure to a single-tablet regimen (STR). This study aimed to evaluate the prevalence of HIV genotypic drug resistance in HIV-1-infected patients with virological failure to STRs in southern Taiwan.

Patients and methods

This retrospective study investigated drug resistance in patients with virological failure to STR from January 2016 to September 2017. Antiretroviral resistance mutations were defined using the 2017 International AIDS Society-USA HIV drug resistance algorithm, and drug resistance was compared using the HIVdb program of the Stanford University HIV Drug Resistance Database. Variables between resistance and non-resistance groups were compared.

Results

Thirty-nine HIV-1-infected patients with treatment failure were tested for resistance, of whom 89% were infected by men who have sex with men. Subtype B HIV-1 strains were found in 90% of the patients. Eight patients were treatment naïve and initiated STRs, while 31 patients experienced treatment failure after switching to STRs. Eighty-seven percent of the patients harbored any of four classes of resistance (nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors (PIs), and integrase strand transfer inhibitors). The prevalence rates of nucleoside reverse transcriptase inhibitor, non-nucleoside reverse transcriptase inhibitor, PI, and integrase strand transfer inhibitor resistance were 72%, 82%, 10%, and 3%, respectively. Patients with PI resistance were more likely to respond to treatment with a non-tenofovir disoproxil fumarate/emtricitabine/efavirenz-based STR (.=0.004) and a longer duration of antiretroviral therapy (101 months [72.0-123.3] vs 11 months [7-44], P=0.007). There were no associations between different STRs and transmission risk factors, HIV subtype, duration of antiretroviral therapy, and resistance to tenofovir disoproxil fumarate.

Conclusion

A high rate of antiretroviral drug resistance was found in the patients who failed STR treatment. The presence of PI resistance in these patients represented an inappropriate switch from a multiple tablet regimen to an STR. These findings should remind clinicians that detailed drug resistance history and close monitoring are mandatory after switching to an STR.

HIV-1 integrase strand-transfer inhibitor resistance in southern Taiwan

The use of antiretroviral therapy has reduced rates of mortality and morbidity in patients with human immunodeficiency virus/acquired immune deficiency syndrome(HIV/AIDS). However, transmission of drug-resistant strains poses a challenge to control the spread of HIV-1. Primary resistance to integrase strand-transfer inhibitors (INSTIs) is rare despite their increased use. The prevalence of transmitted drug resistance (TDR) to INSTIs was 0.9% in northern Taiwan. This study was to analyse the prevalence and risk factors of TDR to INSTIs in southern Taiwan. In this study, we enrolled antiretroviral treatment-naïve HIV-1-infected subjects who underwent voluntary counselling and testing from 2013 to 2016 in southern Taiwan. Genotypic drug resistance, coreceptor tropism (CRT) and INSTI resistance were determined. Logistic regression was used to analyse the risk factors for INSTI polymorphic substitution. Sequences were obtained from 184 consecutive individuals, of whom 96.7% were men who have sex with men and 3.3% were heterosexual. Of the patients, 10% (19/183) had hepatitis B and 33.3% (61/183) had syphilis infection. Subtype B HIV-1 strains were found in 96.1% of the patients. Fifteen patients (8.4%, 15/178) harboured nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors or protease inhibitors resistance. CCR-5 coreceptors were used by 71.4% (130/184) of the patients. None of the patients had INSTI resistance-associated mutations, however 16 patients had INSTI polymorphic substitutions, and they were associated with a higher HIV viral load (p = 0.03, OR 2.4, CI 1.1–5.3) and syphilis infection (p = 0.03, OR 3.7, CI 1.1–12.0). In conclusion, no signature INSTI resistance-associated mutations were detected in our cohort. Continued monitoring of TDR to INSTI is needed due to the increased use of INSTIs.

Surveillance of HIV-1 drug resistance in Xinjiang: high prevalence of K103N in treatment-naïve individuals

To identify transmitted and acquired HIV-1 drug resistance mutations in Xinjiang, China, we collected the peripheral blood of 50 treated and 50 treatment-naïve HIV-1-infected individuals in this region. We successfully amplified 36 reverse transcriptase and 42 protease gene sequences of HIV-1 from 51 individuals and identified mutations associated with resistance to reverse transcriptase (RT) and protease (PR) inhibitors (RTIs and PIs) according to Stanford Drug Resistance Database. Among the drug-treated individuals, the results showed that K103N in the RT region was the most frequent mutation, found in 67% (6/9) of the cases, followed by M184V with 56% (5/9). Five individuals had both nucleoside and non-nucleoside reverse transcriptase inhibitor resistance mutations after more than 12 months of treatment. Among the untreated individuals, 33% (9/27) were found to harbor drug resistance mutations in the RT gene. K103N occurred at the highest rate, accounting for 22% (6/27), followed by P225H (7%) and Y188L (4%). Neither of the two groups showed any major resistance mutations to PIs. Our study revealed that the prevalence of drug resistance was relatively high in Xinjiang and that K103N occurred at the highest rate. These results suggest that it is important to carry out HIV drug resistance testing, especially for the K103N mutation in the RT region, before and during the treatment process. This study may help to guide ART strategies in the Xinjiang region.

Frequency of transmitted drug resistance mutations among treatment-naïve HIV-1-infected individuals at a tertiary care centre in South India

INTRODUCTION

Morbidity and mortality among HIV-1-infected individuals has been dramatically reduced by the implementation of combinational antiretroviral therapy (ART). However, the efficiency of these therapies is compromised due to HIV-1 transmitted drug resistance mutations (TDRMs).

METHODS

We collected a total of 127 samples from ART-naïve HIV-infected individuals and sequenced the pol gene and analysed for drug resistance mutations using the Calibrated Population Resistance (CPR) tool in the Stanford database.

RESULTS

All the 127 clinical samples (100 %) were identified as HIV-1 subtype C. Based on the CPR tool, three strains (2.4 %) had TDRMs, and these were K101E, Y181C and G190A. Our findings correlated well with the WHO surveys conducted in Asia, including India, which consistently reported <5 % TDRM among the specific populations assessed.

CONCLUSION

In countries like India, regular monitoring of TDRMs will provide better information for clinical practice improvement and policy making.