Transmitted HIV Drug Resistance Research Articles

Prevalence of transmitted drug resistance and phylogenetic analysis of HIV-1 among antiretroviral therapy-naïve patients in Northern Vietnam from 2019 to 2022.

Since the rapid expansion of antiretroviral therapy (ART) for HIV, transmitted drug resistance (TDR) has become a major concern in Vietnam. HIV services there are transitioning to be covered by social insurance. Access to pre-exposure prophylaxis (PrEP) is being expanded to tackle the growing HIV epidemic among men who have sex with men. Therefore, a cross-sectional study was conducted at 10 ART facilities in Northern Vietnam from 9th December 2019 to 9th June 2022 to investigate the prevalence and pattern of TDR among ART-naïve people living with HIV (PLWH). TDR mutations were defined according to the World Health Organization 2009 List of Mutations for Surveillance of Transmitted Drug Resistant HIV Strains. Mutation transmission dynamics and TDR clusters were investigated via phylogenetic analysis. We enrolled 391 ART-naïve PLWH. The overall TDR prevalence was 4.6%, with an annual prevalence of 6.0% in 2019/2020, 4.8% in 2021, and 1.3% in 2022. TDR mutations to non-nucleoside reverse transcriptase inhibitors (2.8%), including K103N were the most common. Less commonly, the protease inhibitor-associated mutation M46I and mutations to nucleoside reverse transcriptase inhibitors, including M184V/ I, were observed. CRF01_AE was the most common subtype (77.0%). CRF07_BC (14.3%), which had been rare in Vietnam, was also observed. No genetic association was observed between HIV-1 sequences with TDR mutations. In conclusion, the overall prevalence of TDR was stably low in this region. The phylogenetic tree suggests that TDR clusters have not formed. Continuous monitoring of HIV TDR and strains is crucial to maintaining ART and PrEP efficacy.

Prevalence of acquired and transmitted HIV drug resistance in Iran: a systematic review and meta-analysis.

There is no systematic review on the prevalence of HIV drug resistance (HIVDR) in Iran. We aimed to estimate the prevalence of HIVDR among people living with HIV (PLHIV) in Iran. We assessed HIVDR prevalence in antiretroviral therapy (ART) naïve PLHIV (i.e., those without a history of ART) and PLHIV receiving ART. We systematically searched Scopus, PubMed, Web of Science, Embase, Iranian databases (Iranian Medical Research Information System, Magiran, and Scientific Information Database), the references of studies, and Google Scholar until March 2023. A random-effects model was used to calculate a point estimate and 95% confidence interval (95% CI) for the prevalence of HIVDR in PLHIV. Among 461 potential publications, 22 studies were included in the meta-analysis. The pooled prevalence of acquired HIVDR in PLHIV receiving ART was 34% (95% CI: 19, 50) for nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs), 27% (95% CI: 15, 41) for non-nucleoside reverse transcriptase inhibitors (NNRTIs), and 9% (95% CI: 3, 18) for protease inhibitors (PIs). The pooled prevalence of acquired HIVDR in treatment failure PLHIV was 50% (95% CI: 31, 69) for NRTIs, 49% (95% CI: 29, 69) for NNRTIs, 11% (95% CI: 2, 24) for PIs, and 1% (95% CI: 0, 4) for integrase inhibitors (INIs). The pooled prevalence of transmitted HIVDR in ART-naïve people was 3% (95% CI; 1, 6) for NRTIs, 5% (95% CI: 2, 9) for NNRTIs, and 0 for PIs and INIs. The prevalence of HIVDR was relatively high in both ART-naïve PLHIV and those receiving ART. Without universal pretreatment HIVDR testing and more frequent routine HIV viral load testing among PLHIV who are on ART, the HIVDR prevalence might increase in PLHIV in Iran.

1525. Evolving Trends in HIV Transmitted Drug Resistance in Eastern North Carolina

Abstract Background The impact of HIV/AIDS worldwide is an important public health challenge. One factor that contributes to increased HIV transmission is HIV drug resistance. This occurs from the intrinsic nature of HIV to mutate and eventually replicate in the presence of antiretroviral therapy. The effects of this are development of treatment failure and further transmission amongst cohorts in a given population. The problem of propagated drug resistance is further compounded in populations that present with problems of adherence. A previous study conducted at our institution demonstrated no association with race and transmitted drug resistance. Methods This is a retrospective study that evaluated treatment-naive HIV patients with genotype results from 2016-2020 at East Carolina University infectious disease clinic in Greenville, NC. We collected data on age, race, sex, HIV risk factor, and genotype. A logistic regression model was fit for transmitted HIV resistance with the following covariates: age, gender, race, year, and men who have sex with men (MSM) status. Individual comparisons were made by chi-squared testing for categorical variables or Wilcox ranked sum test for non-normally distributed continuous variables. All observations are presumed to be independent. All data analysis was performed in SAS (SAS Institute Inc., SAS 9.4, Cary, NC: SAS Institute Inc., 2002-2023). Results Of 305 charts reviewed, 245 were included in the analysis. Twenty-six (13.7% African-Americans) versus 14 (25.9% of other races) were found with transmitted drug resistance. Twenty four (16.4%) were MSM. The years with higher transmitted drug resistance detected were 2017-2019 (18.7%, 16.5%, 17.1%, respectively). African American race was found to be protective against transmitted resistance (OR 0.46, 95% CI 0.22-0.98, p = 0.04) when adjusting for MSM status, Sex, Age, and Year. The result was also significant in the unadjusted analysis (χ2 = 4.60, p = 0.03). Non-African Americans were 2.17 times more likely to have transmitted resistance than African Americans.Table 1:Patient Characteristics. Patient characteristics presented as proportion and percentage for categorical variables and median and standard deviation for continuous variables.Table 2:Adjusted logistic regression for variable effect on transmitted antiviral resistance Conclusion African American race was found to be protective against transmitted resistance (OR 0.46, 95% CI 0.22-0.98, p = 0.04) when adjusting for MSM status, sex, age, and year. This is a change from the results of our previous study. Disclosures All Authors: No reported disclosures

Modelling the impact of treatment adherence on the transmission of HIV drug resistance.

A lower adherence rate (percentage of individuals taking drugs as prescribed) to ART may increase the risk of emergence and transmission of HIV drug resistance, decrease treatment efficacy, and increase mortality rate. Exploring the impact of ART adherence on the transmission of drug resistance could provide insights in controlling the HIV epidemic. We proposed a dynamic transmission model incorporating the CD4 cell count-dependent rates of diagnosis, treatment and adherence with transmitted drug resistance (TDR) and acquired drug resistance. This model was calibrated and validated by 2008-2018 HIV/AIDS surveillance data and prevalence of TDR among newly diagnosed treatment-naive individuals from Guangxi, China, respectively. We aimed to identify the impact of adherence on drug resistance and deaths during expanding ART. In the base case (ART at 90% adherence and 79% coverage), we projected the cumulative total new infections, new drug-resistant infections, and HIV-related deaths between 2022 and 2050 would be 420 539, 34 751 and 321 671. Increasing coverage to 95% would reduce the above total new infections (deaths) by 18.85% (15.75%). Reducing adherence to below 57.08% (40.84%) would offset these benefits of increasing coverage to 95% in reducing infections (deaths). Every 10% decrease in adherence would need 5.07% (3.62%) increase in coverage to avoid an increase in infections (deaths). Increasing coverage to 95% with 90% (80%) adherence would increase the above drug-resistant infections by 11.66% (32.98%). A decrease in adherence might offset the benefits of ART expansion and exacerbate the transmission of drug resistance. Ensuring treated patients' adherence might be as important as expanding ART to untreated individuals.

Increased prevalence and stable clustering rate of HIV-1 transmitted drug resistance strains after 'treat-all' in a megacity of China.

The 'treat-all' strategy was implemented in Shenzhen, China in 2016. The effect of this extensive treatment on transmitted drug resistance (TDR) of HIV is unclear. TDR analysis was performed, based on the partial HIV-1 pol gene obtained from the newly reported HIV-1 positive cases from 2011 to 2019 in Shenzhen, China. The HIV-1 molecular transmission networks were inferred to analyse the spread of TDR. Logistic regression was used to identify the potential risk factors with TDR mutations (TDRMs) to cluster. A total of 12 320 partial pol sequences were included in this study. The prevalence of TDR was 2.95% (363/12 320), which increased from 2.57% to 3.52% after 'treat-all'. The TDR prevalence was increased in populations with the characteristics of CRF07_BC, being single, educated to junior college level and above, MSM and male. The sensitivities of viruses to six antiretroviral drugs were decreased. The clustering rate of TDRMs remained stable, and the sequences in the three drug resistance transmission clusters (DRTCs) were mainly found during 2011-16. CRF07_BC and CRF55_01B were the factors associated with TDRMs clustering in the networks. The 'treat-all' strategy might have contributed to a small increase in TDR, while most of the TDRMs were distributed sporadically, which implies that the 'treat-all' strategy is helpful for the control of TDR in high-risk populations.

Transmitted HIV Drug Resistance in Bulgaria Occurs in Clusters of Individuals from Different Transmission Groups and Various Subtypes (2012-2020).

Transmitted HIV drug resistance in Bulgaria was first reported in 2015 using data from 1988-2011. We determined the prevalence of surveillance drug resistance mutations (SDRMs) and HIV-1 genetic diversity in Bulgaria during 2012-2020 using polymerase sequences from 1053 of 2010 (52.4%) antiretroviral therapy (ART)-naive individuals. Sequences were analyzed for DRM using the WHO HIV SDRM list implemented in the calculated population resistance tool at Stanford University. Genetic diversity was inferred using automated subtyping tools and phylogenetics. Cluster detection and characterization was performed using MicrobeTrace. The overall rate of SDRMs was 5.7% (60/1053), with 2.2% having resistance to nucleoside reverse transcriptase inhibitors (NRTIs), 1.8% to non-nucleoside reverse transcriptase inhibitors (NNRTIs), 2.1% to protease inhibitors (PIs), and 0.4% with dual-class SDRMs. We found high HIV-1 diversity, with the majority being subtype B (60.4%), followed by F1 (6.9%), CRF02_AG (5.2%), A1 (3.7%), CRF12_BF (0.8%), and other subtypes and recombinant forms (23%). Most (34/60, 56.7%) of the SDRMs were present in transmission clusters of different subtypes composed mostly of male-to-male sexual contact (MMSC), including a 14-member cluster of subtype B sequences from 12 MMSC and two males reporting heterosexual contact; 13 had the L90M PI mutation and one had the T215S NRTI SDRM. We found a low SDRM prevalence amid high HIV-1 diversity among ART-naive patients in Bulgaria during 2012-2020. The majority of SDRMs were found in transmission clusters containing MMSC, indicative of onward spread of SDRM in drug-naive individuals. Our study provides valuable information on the transmission dynamics of HIV drug resistance in the context of high genetic diversity in Bulgaria, for the development of enhanced prevention strategies to end the epidemic.

The impact of attrition on the transmission of HIV and drug resistance: A mathematical modelling study.

Attrition due to loss to follow-up or termination of antiretroviral therapy (ART) among HIV-infected patients in care may increase the risk of emergence and transmission of drug resistance (TDR), diminish benefit of treatment, and increase morbidity and mortality. Understanding the impact of attrition on the epidemic is essential to provide interventions for improving retention in care. We developed a comprehensive HIV transmission dynamics model by considering CD4+ cell count dependent diagnosis, treatment, and attrition involving TDR and acquired drug resistance. The model was calibrated by 11 groups HIV/AIDS surveillance data during 2008-2018 from Guangxi, China, and validated by the prevalence of TDR among diagnosed treat-naive individuals. We aimed to investigate how attrition would affect the transmission of HIV and drug-resistance when expanding ART. In the base case with CD4+ cell count dependent per capita attrition rates 0.025∼0.15 and treatment rates 0.23∼0.42, we projected cumulative total new infections, new drug-resistant infections, and HIV-related deaths over 2022-2030 would be 145 391, 7637, and 51 965, respectively. Increasing treatment rates by 0.1∼0.2 can decrease the above total new infections (deaths) by 1.63∼2.93% (3.52∼6.16%). However, even 0.0114∼0.0220 (0.0352∼0.0695) increase in attrition rates would offset this benefit of decreasing infections (deaths). Increasing treatment rates (attrition rates) by 0.05∼0.1 would increase the above drug-resistant infections by 0.16∼0.30% (22.18∼41.15%). A minor increase in attrition can offset the benefit of treatment expansion and increase the transmission of HIV drug resistance. Reducing attrition rates for patients already in treatment may be as important as expanding treatment for untreated patients.

No transmitted drug resistance to HIV integrase strand-transfer inhibitors after their scale-up in Estonia in 2017

In Eastern Europe HIV-1 transmitted drug resistance (TDR) data, especially in integrase (IN) region is limited. In Estonia INSTI (Integrase Strand Transfer Inhibitors) TDR has been studied only prior to the INSTI scale-up in late 2010s. Current study aimed to determine the levels of protease (PR), reverse transcriptase (RT) and IN surveillance drug resistance mutations (SDRMs) among newly diagnosed patients in Estonia in 2017. Study included 216 newly diagnosed HIV-1 individuals from January 1 until December 31, 2017 in Estonia. Demographic and clinical data were obtained from the Estonian Health Board, Estonian HIV Cohort Study (E-HIV) and clinical laboratories' databases. The PR-RT and IN regions were sequenced and analyzed for SDRMs and subtype determination. Seventy-one percent (151/213) of available HIV-positive samples were successfully sequenced. The overall level of TDR was 7.9% (12/151; 95% CI 4.4-13.8%); no dual or triple class resistance was detected. No major INSTI mutations were found. The distribution of SDRMs for NNRTI, NRTI and PI was 5.9% (9/151), 1.3% (2/151) and 0.7% (1/151), respectively. The predominant NNRTI mutation was K103N. CRF06_cpx was predominant variant (59%) in Estonian HIV-1 population followed by subtype A (9%) and subtype B (8%). Although no major INSTI mutations were found, close monitoring of INSTI SDRMs is needed considering the extensive use of the first and second-generation INSTIs. PR-RT TDR is slowly rising in Estonia indicating the need for continuous surveillance in the future. Low genetic barrier NNRTIs should be avoided in the treatment regimens.

Strategies to overcome HIV drug resistance-current and future perspectives.

The availability of combined antiretroviral therapy (cART) has revolutionized the course of HIV infection, suppressing HIV viremia, restoring the immune system, and improving the quality of life of HIV infected patients. However, the emergence of drug resistant and multidrug resistant strains remains an important contributor to cART failure, associated with a higher risk of HIV-disease progression and mortality. According to the latest WHO HIV Drug Resistance Report, the prevalence of acquired and transmitted HIV drug resistance in ART naive individuals has exponentially increased in the recent years, being an important obstacle in ending HIV-1 epidemic as a public health threat by 2030. The prevalence of three and four-class resistance is estimated to range from 5 to 10% in Europe and less than 3% in North America. The new drug development strategies are focused on improved safety and resistance profile within the existing antiretroviral classes, discovery of drugs with novel mechanisms of action (e.g., attachment/post-attachment inhibitors, capsid inhibitors, maturation inhibitors, nucleoside reverse transcriptase translocation inhibitors), combination therapies with improved adherence, and treatment simplification with infrequent dosing. This review highlight the current progress in the management of salvage therapy for patients with multidrug-resistant HIV-1 infection, discussing the recently approved and under development antiretroviral agents, as well as the new drug targets that are providing a new avenue for the development of therapeutic interventions in HIV infection.

The Effect of Pretreatment Potential Resistance to NNRTIs on Antiviral Therapy in Patients With HIV/AIDS

With the increasing coverage of antiretroviral therapy, concerns for the emergence and transmission of HIV drug resistance (HIVDR) are arising. HIVDR was divided into 5 levels: sensitive, potentially resistant, low resistant, intermediate resistant, and high resistant. Most of the articles on HIVDR involved low-level, intermediate-level, and high-level drug resistance to antiretroviral drug, and few articles deal with potential drug resistance. Treatment failure associated with the level of low-level, intermediate-level, and high-level resistance to antiretroviral drug has been reported. However, whether virological failure (VF) is related to potential resistance remains unclear. In this study, we aimed to describe the situation of potential resistance to antiretroviral drug and whether it is related to VF. We analyzed the demographic, behavioral information, medical history, and drug resistance-associated mutation data from subjects. Drug resistance mutations at baseline and time of failure in patients suffering VF were detected by using the Vela automated next-generation sequencing platform. The χ2 test or Fisher exact test and logistic regression were used to assess the risk factors that contribute to VF in the potential drug-resistant people. The prevalence of overall pretreatment drug resistance was 7.06% (233/3300), and the prevalence of pretreatment potential resistance was 8.79% (290/3300). All these patients with pretreatment potential first-line drugs resistance showed potential resistance to nonnucleoside reverse transcriptase inhibitors (NNRTIs), and some of them had potential drug resistance to NNRTIs and NRTIs or NNRTIs and PIs; among these patients, 94.71% (179/189) had V179 D/E mutations. The VF rate of first-line treatment for potentially resistant people is 17.99%. CD4+ T-cell count ≤200 cells/L at antiretroviral therapy initiation are risk factors for the failure of first-line treatment. The prevalence of potential drug resistance among individuals with HIV and the VF rate of first-line treatment for potential drug-resistant people were high. To better optimize clinical management, prevention, and control of HIV, attention should be devoted to the potential resistance of nonnucleoside drugs.

Low Prevalence of Transmitted HIV-1 Antiretroviral Resistance in Pregnant Women from Rio de Janeiro, Brazil

Background: HIV screening during antenatal care is being expanded in Brazil for early diagnosis of HIV-1 infection during pregnancy and prevention of vertical transmission. HIV genotyping in pregnant women is crucial to reduce the risk of vertical transmission in those carrying resistant strains and may also be used for Transmitted Drug Resistance (TDR) surveillance purpose. We evaluated prevalence and patterns of HIV-1 TDR and HIV subtype distribution in recently diagnosed ARV naïve pregnant women from Rio de Janeiro, Brazil. Methods: 299 blood samples of recently diagnosed HIV-1-infected pregnant women from four reference antenatal care public health units in Rio de Janeiro were consecutively collected and analyzed from 2005 to 2015.ViroseqTM (Abbott) and TrugeneTM HIV-1 Genotyping Systems (Siemens) were used for genotyping and the Standford Algorithm for Interpretation of HIV-1 Resistance for TDR and subtype identification. Results: The most prevalent HIV-1 subtype was the subtype B (77%), followed by subtype F (15%), BF recombinant forms (4%), subtype C (2%) and the recombinant forms: CRF02_AG, CRF31_BC and DF identified in one subject each. Overall, the TDR mutations was 11.7%, 2.7% associated to the Nucleoside Reverse Transcriptase Inhibitors (NRTIs) of the samples, 2.7% to Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) and 1% to Protease Inhibitors (PIs). Mutations associated with NRTI resistance were TAMs, F77L, M184V; associated with NNRTI resistance were K103N, Y188H and L100I and. mutations associated to PIs were D30N, M46I, and V82L. Conclusions: HIV-1 subtype B was the most prevalent subtype observed in our study. For the first time infections with the circulating recombinant forms CRF02_AG and CRF31_BC were described in a pregnant woman, suggesting the spread of African derived virus in Brazil and the introduction in Rio de Janeiro of the CRF31_BC coming from South Brazil. Our results strongly suggest the need of establishing a regular surveillance system for transmitted HIV-1 drug resistance in pregnant women in Brazil and its integration in antenatal care management policies for HIV-1 infected women should be considered.

Molecular Epidemiology and Trends in HIV-1 Transmitted Drug Resistance in Mozambique 1999-2018.

HIV drug resistance (HIVDR) can become a public health concern, especially in low- and middle-income countries where genotypic testing for people initiating antiretroviral therapy (ART) is not available. For first-line regimens to remain effective, levels of transmitted drug resistance (TDR) need to be monitored over time. To determine the temporal trends of TDR in Mozambique, a search for studies in PubMed and sequences in GenBank was performed. Only studies covering the pol region that described HIVDR and genetic diversity from treatment naïve patients were included. A dataset from seven published studies and one novel unpublished study conducted between 1999 and 2018 were included. The Calibrated Population Resistance tool (CPR) and REGA HIV-1 Subtyping Tool version 3 for sequences pooled by sampling year were used to determine resistance mutations and subtypes, respectively. The prevalence of HIVDR amongst treatment-naïve individuals increased over time, reaching 14.4% in 2018. The increase was most prominent for non-nucleoside reverse transcriptase inhibitors (NNRTIs), reaching 12.7% in 2018. Subtype C was predominant in all regions, but a higher genetic variability (19% non-subtype C) was observed in the north region of Mozambique. These findings confirm a higher diversity of HIV in the north of the country and an increased prevalence of NNRTI resistance among treatment naïve individuals over time.

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

BackgroundThe prevalence of transmitted drug resistance (TDR) after the universal implementation of STRs is unknown in Taiwan.ObjectiveThis 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.MethodsAdult 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.ResultsA 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.ConclusionOur findings showed a stable prevalence rate of transmitted drug resistance despite the implementation of STRs as the first-line therapy in June 2016.

Cost-effectiveness of oral pre-exposure prophylaxis and expanded antiretroviral therapy for preventing HIV infections in the presence of drug resistance among men who have sex with men in China: A mathematical modelling study

SummaryBackgroundOral pre-exposure prophylaxis (PrEP) and antiretroviral therapy (ART) can effectively prevent HIV infections among men who have sex with men (MSM), but the emergence and transmission of HIV drug-resistance (HIVDR) may compromise their benefits. The costs and benefits of expanding PrEP and ART coverage in the presence of HIVDR in China remain unknown.MethodsWe developed a comprehensive dynamic transmission model incorporating the transmitted (TDR) and acquired (ADR) HIV drug resistance. The model was calibrated by the HIV surveillance data from 2009 to 2019 among MSM in Jiangsu Province, China, and validated by the dynamic prevalence of ADR and TDR. We aimed to investigate the impact of eight intervention scenarios (no PrEP, 20%, 50% or 80% of PrEP, without (77% coverage) or with (90% coverage) expanded ART) on the HIV epidemic trend and cost-effectiveness of PrEP over the next 30 years.Findings20% or 50% PrEP + 90% ART would be cost-effective, with an incremental cost-effectiveness ratio (ICER) of 25,417 (95% confidence interval [CI]: 12,390–38,445) or 47,243 (23,756–70,729), and would yield 154,949 (89,662–220,237) or 179,456 (102,570–256,342) incremental quality-adjusted life-years (QALYs) over the next 30 years. No PrEP + 90% ART would yield 125,211 (73,448–176,974) incremental QALYs and be cost-saving. However, 20–80% PrEP + 77% ART and 80% PrEP + 90% ART with ICER of $77,862–$98,338 and $63,332, respectively, and were not cost-effective. A reduction of 64% in the annual cost of oral PrEP would make it highly cost-effective for 50% PrEP + 90% ART.Interpretation20% or 50% PrEP + 90% ART is cost-effective for HIV control in the presence of HIVDR. Expanded ART alone may be the optimal policy under the current limited budgets.FundingNational Natural Science Foundation of China, the National S&T Major Project Foundation of China.

The prevalence of pre-treatment and acquired HIV drug resistance in Vietnam: a nationally representative survey, 2017-2018.

IntroductionMonitoring the population‐level emergence and transmission of HIV drug resistance (HIVDR) is necessary for supporting public health programmes. This study provides a nationally representative prevalence estimate of HIVDR in people initiating antiretroviral therapy (ART) and estimates of acquired HIVDR and viral load (VL) suppression in people who have received it for 12 or ≥48 months in Vietnam.MethodsThe study was conducted between September 2017 and March 2018 following World Health Organization guidance. Thirty ART clinics were randomly sampled using probability proportional to size sampling from a total of 367 ART clinics in the country.Results and DiscussionIn total, 409 patients initiating ART were enrolled into the survey of pre‐treatment HIVDR. The prevalence of any pre‐treatment HIVDR was 5.8% (95% CI 3.4–9.5%), and the prevalence of non‐nucleoside reverse transcriptase inhibitor resistance was 3.4% (95% CI 1.8–6.2%). Four hundred twenty‐nine patients on ART for 12±3 months and 723 patients on ART for ≥48 months were enrolled into the surveys of acquired HIVDR. The prevalence of VL suppression (defined as <1000 copies/ml) in patients on ART for 12±3 and ≥48 months was 95.5% (95% CI 91.3–97.8%) and 96.1% (95% CI 93.2–97.8%), respectively. Among individuals with viral non‐suppression, any HIVDR was detected in 11/14 (weighted prevalence 74.3%) of those on ART for 12±3 months and in 24/27 (weighted prevalence 88.5%) of those receiving ART for ≥48 months.ConclusionsThis nationally representative study of HIVDR found high levels of VL suppression among those on ART for 12 and ≥48 months. Overall, high levels of VL suppression at both time points suggested good adherence among patients receiving ART and quality of treatment services in Vietnam.Clinical Trial NumberNot applicable

Epidemiology and Transmitted HIV-1 Drug Resistance among Treatment-Naïve Individuals in Israel, 2010-2018.

Despite the low prevalence of HIV-1 in Israel, continuous waves of immigration may have impacted the local epidemic. We characterized all people diagnosed with HIV-1 in Israel in 2010–2018. The demographics and clinical data of all individuals (n = 3639) newly diagnosed with HIV-1 were retrieved. Subtypes, transmitted drug-resistance mutations (TDRM), and phylogenetic relations, were determined in >50% of them. In 39.1%, HIV-1 transmission was through heterosexual contact; 34.3% were men who have sex with men (MSM); and 10.4% were people who inject drugs. Many (>65%) were immigrants. Israeli-born individuals were mostly (78.3%) MSM, whereas only 9% of those born in Sub-Saharan Africa (SSA), Eastern Europe and Central Asia (EEU/CA), were MSM. The proportion of individuals from SSA decreased through the years 2010–2018 (21.1% in 2010–2012; 16.8% in 2016–2018) whereas those from EEU/CA increased significantly (21% in 2010–2012; 27.8% in 2016–2018, p < 0.001). TDRM were identified in 12.1%; 3.7, 3.3 and 6.6% had protease inhibitors (PI), nucleotide reverse transcriptase inhibitors (NRTI), and non-nucleoside reverse transcriptase inhibitors (NNRTI) TDRM, respectively, with the overall proportion remaining stable in the studied years. None had integrase TDRM. Subtype B was present in 43.9%, subtype A in 25.2% (A6 in 22.8 and A1 in 2.4%) and subtype C in 17.1% of individuals. Most MSM had subtype B. Subtype C carriers formed small clusters (with one unexpected MSM cluster), A1 formed a cluster mainly of locally-born patients with NNRTI mutations, and A6 formed a looser cluster of individuals mainly from EEU. Israelis, <50 years old, carrying A1, had the highest risk for having TDRM. In conclusion, an increase in immigrants from EEU/CA and a decrease in those from SSA characterized the HIV-1 epidemic in 2010–2018. Baseline resistance testing should still be recommended to identify TDRM, and improve surveillance and care.

Transmitted HIV-1 Drug-resistance Mutations among Newly Diagnosed Patients of the North Western Region of Cameroon

Background: First line antiretroviral treatment (ART) regimens in Cameroon comprises of reverse transcriptase inhibitors (RTIs). As ART continues to expand, the emergence of HIV drug resistance mutations (DRMs) is a challenging problem. The ongoing scale up of ART in Cameroon has prompted the interest in surveillance of transmitted drug resistance (TDR).  The aim of this study was to evaluate the prevalence of TDR among drug naïve individuals residing in the North West Region (NWR) of Cameroon.&#x0D; Methods: Ethics approval was obtained from the National Ethics Committee of Cameroon and patients informed consents were obtained. A total of 81 HIV-1 infected and drug naïve patients were recruited from randomly selected clinics located in the NWR of Cameroon from February 2016 and April 2016. HIV-1 protease-reverse transcriptase region was sequenced using an in-house protocol. HIV drug resistance mutations were identified and analyzed using Stanford HIVDR database and the Calibrated Population Resistance (CPR) tools. Data was analyzed using SPSS version 23.&#x0D; Results: Of the 81 samples analyzed, the prevalence of TDR was 11.1% (9/81). Of these 9.9% (8/81) had drug resistance mutations to nucleoside and non-nucleoside reverse transcriptase inhibitors (NRTIs and NNRTIs) and a single individual (1.2%) with protease inhibitors. A total of 8.6 % (7/81), 4.9(4/81), and 3.7 % (3/81) individuals had a major mutation to NRTIs, NNRTIs, and both NRTIs and NNRTIs respectively. Thymidine analogue mutations [TAM] (M41ML, D67N, K70T/R, T215TA/F, and K219Q) were detected in five individuals.  The most frequent NRTI and NNRTI DRMs were K219Q (n=2) and E138A (n=2) respectively. Mutations associated with NRTIs were TAM and M184MV; NNRTIs were A98G, K103N, V108I, V179E, and Y181C and I54IFV for PI. CPR tool revealed a 4.9% (4/81) prevalence with the following single mutations K103N D67N, K70R, M184V, T215F, K219Q.The difference between two methods was statistically significant p=0.0001. These mutations confer resistance to all NRTIs and NNRTIs drugs.&#x0D; Conclusions: Although moderate transmitted drug resistance (11.1%) levels were detected in this study, this calls for routine drug resistance surveillance among patients on ART. This will ensure relative maintenance of low viral suppression amongst HIV patients.

Statewide Longitudinal Trends in Transmitted HIV-1 Drug Resistance in Rhode Island, USA.

BackgroundHIV-1 transmitted drug resistance (TDR) remains a global challenge that can impact care, yet its comprehensive assessment is limited and heterogenous. We longitudinally characterized statewide TDR in Rhode Island.MethodsDemographic and clinical data from treatment-naïve individuals were linked to protease, reverse transcriptase, and integrase sequences routinely obtained over 2004–2020. TDR extent, trends, impact on first-line regimens, and association with transmission networks were assessed using the Stanford Database, Mann-Kendall statistic, and phylogenetic tools.ResultsIn 1123 individuals, TDR to any antiretroviral increased from 8% (2004) to 26% (2020), driven by non-nucleotide reverse transcriptase inhibitor (NNRTI; 5%–18%) and, to a lesser extent, nucleotide reverse transcriptase inhibitor (NRTI; 2%–8%) TDR. Dual- and triple-class TDR rates were low, and major integrase strand transfer inhibitor resistance was absent. Predicted intermediate to high resistance was in 77% of those with TDR, with differential suppression patterns. Among all individuals, 34% were in molecular clusters, some only with members with TDR who shared mutations. Among clustered individuals, people with TDR were more likely in small clusters.ConclusionsIn a unique (statewide) assessment over 2004–2020, TDR increased; this was primarily, but not solely, driven by NNRTIs, impacting antiretroviral regimens. Limited TDR to multiclass regimens and pre-exposure prophylaxis are encouraging; however, surveillance and its integration with molecular epidemiology should continue in order to potentially improve care and prevention interventions.

Transmitted Drug Resistance in Antiretroviral Therapy-Naive Persons With Acute/Early/Primary HIV Infection: A Systematic Review and Meta-Analysis.

Background: The widespread use of antiretroviral therapy (ART) has raised concerns about the emergence of HIV transmitted drug resistance (TDR). Acute HIV infection (AHI) was the most appropriate time to detect the spread of TDR. In this meta-analysis, our purpose was to evaluate the level of TDR in ART-naive patients with primary HIV infection (PHI)/AHI/early HIV infection (EHI) and to describe the critical drug-resistant mutations. Methods: We systematically searched the literature between January 1, 2008, and April 30, 2021, in PubMed, Web of Science, Embase, and the Cochrane Library. To evaluate the overall prevalence of TDR, we extracted raw data and analyzed prevalence estimates using Stata SE. Results: The data of this meta-analysis come from 12 observational studies, covering 3,558 ART-naive individuals with PHI, AHI, or EHI. The overall prevalence of HIV-TDR is 9.3% (95% CI: 6.8%–11.8%, I2 = 81.1%, in 11 studies). The prevalence of resistance by drug class is the highest for the nonnucleoside reverse transcriptase inhibitors (NNRTIs) at 5.7% (95% CI: 2.9%–8.5%, I2 = 96.6%, in 11 studies), followed by nucleoside reverse transcriptase inhibitors (NRTIs) at 3.4% (95% CI: 1.8%–5.0%, I2 = 86.3%, in 10 studies) and protease inhibitors (PIs) at 3.3% (95% CI: 2.7%–3.9%, I2 = 15.6%, in 10 studies). The prevalence of TDR to integrase inhibitors (INIs) is 0.3% (95% CI: 0.1%–0.7%, I2 = 95.9%, in three studies), which is the lowest among all antiretroviral drugs. Conclusion: The overall prevalence of TDR is at a moderate level among AHI patients who have never received ART. This emphasizes the importance of baseline drug resistance testing for public health surveillance and guiding the choice of ART. In addition, the prevalence of TDR to NNRTIs is the highest, while the TDR to INIs is the lowest. This may guide the selection of clinical antiretroviral drugs.

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

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