Prevalence Of Pretreatment Drug Resistance Research Articles

Pretreatment and acquired HIV drug resistance in Belize—results of nationally representative surveys, 2021–22

Abstract Background The rising prevalence of pretreatment drug resistance (PDR) to non-nucleoside reverse-transcriptase inhibitors threatens the effectiveness of ART. In response, the WHO recommends dolutegravir-based ART regimens due to their high genetic barrier to resistance and better treatment outcomes. This is expected to contribute to achieving the Joint United Nations Programme on HIV/AIDS (UNAIDS) target of 95% viral suppression in people on ART. Objectives To estimate the prevalence of PDR among adults initiating ART and assess viral suppression and acquired HIV drug resistance (ADR) among individuals receiving ART in Belize. Patients and methods Nationally representative cross-sectional PDR and ADR surveys were conducted between 2021 and 2022. Sixty-seven adults were included in the PDR survey, and 43 children and adolescents and 331 adults were included in the ADR survey. Demographic and clinic data and blood specimens were collected. HIV drug resistance (HIVDR) was predicted using the Stanford HIVdb tool. Results The prevalence of PDR to efavirenz or nevirapine in adults was 49.3% (95% CI 42.2%–56.4%) and was significantly higher in those with previous antiretroviral exposure (OR: 7.16; 95% CI 2.71–18.95; P = 0.002). Among children and adolescents receiving ART, 50.0% had viral suppression, with better rates for those receiving dolutegravir-based ART (OR: 5.31; 95% CI 3.02–9.34; P < 0.001). In adults, 79.6% achieved viral suppression. No resistance to integrase inhibitors was observed in those on dolutegravir-based ART. Conclusions Prioritizing dolutegravir-based ART is critical for achieving HIV epidemic control in Belize. Efforts should focus on retention in care and adherence support to prevent HIVDR.

Transmission Network and Phylogenetic Analysis Highlight the Role of Suburban Population in HIV-1 Transmission Among Older Adults in Nanjing, Jiangsu Province, China.

Describing the transmission characteristics among older adults is essential for designing tailored interventions. An epidemiological investigation combined with phylogenetic analysis was conducted to reveal potential transmission linkages among older adults in Nanjing. Between 2018 and 2022, 188 pol sequences were successfully amplified. Multiple genotypes were identified, including CRF07_BC (55.3%), CRF01_AE (30.3%), CRF08_BC (8.0%), B (3.2%), CRF55_01B (1.1%), CRF67_01B (0.5%), CRF68_01B (0.5%), and unique recombinant forms (URF) (1.1%). Transmission network analysis identified 120 genetically linked patients forming 23 clusters, ranging from 2 to 26 individuals. Multivariable logistic regression analysis showed that compared with farmers and heterosexuals, patients with other occupations (OR = 0.404, 95% CI: 0.173-0.945) and MSM (OR = 0.193, 95% CI: 0.050-0.738) were less likely to have high linkage. Subjects who lived in suburban areas were more likely to have high linkage (OR = 10.932, 95% CI: 3.335-35.830). The Sankey diagram suggested that patients living in suburban areas primarily transmitted the disease within the local district (χ2 = 24.192, p < 0.001). Among the 188 pol sequences, the prevalence of pretreatment drug resistance was 8%. In suburban areas with a rising HIV-1 epidemic, improving early detection and timely treatment is critical. More tailored interventions for this subgroup are urgently needed.

Epidemiological dynamics and molecular characterization of HIV drug resistance in eastern China from 2020 to 2023.

HIV drug resistance (HIVDR) has become a threat to the elimination of the AIDS epidemic due to the global scale-up of antiretroviral therapy (ART) for HIV-infected individuals. This study aims to investigate the epidemiological dynamics and molecular characterization of HIV pretreatment drug resistance (PDR) and acquired drug resistance (ADR) in Hangzhou, a developed region in China. An epidemiological survey combined with a molecular transmission network and Bayesian analysis was conducted. A total of 3,596 individuals with newly confirmed HIV infections (from 2020 to 2023) and 164 individuals with ART failure (from 2021 to 2023) were included. The molecular transmission network was used to identify key drug-resistant transmission clusters, while the Bayesian analysis was utilized to trace the origins and spread of these clusters. The overall prevalence of PDR was found to be 8.4% (303/3596). Among these cases, PDR to non-nucleoside reverse transcriptase inhibitors (NNRTIs) accounted for 4.7% (170/3596), significantly higher than the resistance observed for protease inhibitors (PIs; 2.8%, p < 0.001) and nucleoside reverse transcriptase inhibitors (NRTIs; 1.4%, p < 0.001). Multivariate logistic regression analysis revealed a significantly higher PDR value among individuals infected with the CRF07_BC subtype compared to those with the CRF08_BC subtype (aOR = 0.56, 95% CI = 0.359-0.859, p = 0.008). The molecular transmission network analysis identified the transmission of the drug resistance mutation (DRM) Q58E within the clusters of the CRF07_BC subtype. The Bayesian analysis suggested that these clusters were introduced into Hangzhou from Shenzhen between 2005 and 2012. Furthermore, the study highlighted 50.6% (83/164) prevalence of ADR among individuals experiencing ART failure. The combined molecular network analysis of virological failure and newly confirmed HIV infections indicated the transmission of the K103N mutation between these groups. In conclusion, targeted interventions may be necessary for specific subtypes and transmission clusters to control the spread of drug-resistant HIV. Continuous monitoring of resistance patterns is critical to inform treatment strategies and optimize ART regimens.

Pretreatment drug resistance among people living with HIV from 2018 to 2022 in Guangzhou, China.

The presence of pretreatment drug resistance (PDR) is posing an increasing threat to HIV control. Here we investigated drug resistance mutations (DRMs) and PDR among 6831 HIV-infected individuals from 2018 to 2022 in Guangzhou, China. DRMs were detected among 24.5% of the patients. The overall prevalence of PDR was 7.4%, with resistance rate to nucleotide reverse transcriptase inhibitor (NRTI) being 1.3%, nonnucleoside reverse transcriptase inhibitor (NNRTI) 4.8%, and protease inhibitor (PI) 1.4%. Abacavir (0.8%) resistance was the most common in NRTI, followed by resistance to emtricitabine (0.6%), lamivudine (0.6%), and tenofovir disoproxil fumarate (0.3%). In NNRTI, nevirapine (3.7%) resistance was the most common, followed by efavirenz (3.5%) and rilpivirine (3.4%). Among PI, resistance to tipranavir (0.8%), nelfinavir (0.6%), fosamprenavir (0.2%) and lopinavir (0.1%) was most frequent. Annual prevalence of PDR showed an increase trend from 2018 to 2022, although not significant. In the multivariable logistic regression model, hepatitis B surface antigen positivity, circulating recombinant form (CRF) 55_01B, CRF08_BC, CRF59_01B, and subtype B were demonstrated as associated risk factors for PDR. The overall prevalence of PDR in Guangzhou was moderate, with relatively severe NNRTI resistance. Therefore, it remains crucial to continue monitoring PDR among newly diagnosed HIV-infected individuals.

Molecular transmission network analysis reveals the challenge of HIV-1 in ageing patients in China: elderly people play a crucial role in the transmission of subtypes and high pretreatment drug resistance in developed Eastern China, 2019–2023

BackgroundThe number and proportion of HIV/AIDS patients among older people are continuously and rapidly increasing in China. We conducted a detailed molecular epidemiological analysis of HIV-1 epidemic strains in a developed city in eastern China and found that elderly people play a crucial role in the transmission of subtypes and high pretreatment drug resistance (PDR).MethodsA total of 1048 samples were obtained from 1129 (92.8%) newly confirmed HIV-1-positive and treatment-naive patients between 2019 and 2023. The 1316 bp target fragment of the pol gene was amplified by reverse transcription polymerase chain reaction (RT‒PCR) and nested PCR, and Maximum-likelihood (ML) phylogenetic trees and molecular transmission network were constructed to analyse the subtypes and transmission clusters. Molecular transmission network was visualized using Cytoscape with the distance threshold of 0.0075. PDR-associated mutations were determined according to the Stanford University HIV Drug Resistance Database.ResultsA total of 933 pol sequences (89.0%, 933/1048) were successfully obtained, and twelve HIV-1 subtypes were detected. CRF07_BC was the predominant subtype, accounting for 48.1% (449/933) of sequences, followed by CRF01_AE (29.4%, 274/933). A total of 398 individuals (42.7%, 398/933) formed 89 clusters in the network. Multivariable logistic regression analysis revealed that age, nationality, subtype, and PDR were the most significant factors associated with clustering in the transmission network. The prevalence of PDR was 14.6% (136/933).PDR associated with non-nucleoside reverse transcriptase inhibitors (10.0%, 93/933) was much more common than that associated with nucleoside reverse transcriptase inhibitors (1.8%, 17/933) and protease inhibitors (3.2%, 30/933) (χ2 = 77.961, p < 0.001). The most frequent NNRTI mutations were K103N/S/KN/NS (52.2%, 71/136), which led to the highest proportion of high-level resistance to nevirapine and efavirenz (52.2%).ConclusionsOur study revealed the important influence of elderly people on CRF07_BC transmission and the high prevalence of PDR. The clustering of drug-resistant cases was significant, which suggested the potential for localized widespread transmission of drug-resistant strains. HIV screening and the determination of PDR are recommended for older patients to improve early detection and reduce treatment failure and second-generation transmission.

Exploring disparities in HIV-1 pretreatment and acquired drug resistance in China from 2003 to 2022.

To investigate the epidemic patterns of pretreatment drug resistance (PDR) and acquired drug resistance (ADR) in HIV-1 sequences from China. HIV-1 pol sequences and associated epidemiological data were collected from the Los Alamos HIV Sequence Database, NCBI, HIV Gene Sequence Database and PubMed. Genotypic resistance and subtypes were identified using the Stanford HIV Drug Resistance Database. A total of 36 263 sequences from ART-naïve individuals and 1548 sequences from ART-experienced individuals with virological failure were evaluated. PDR prevalence was 6.64%, initially decreasing and then increasing to 7.84% (2018-22) due to NNRTI. Pooled ADR prevalence (44.96%) increased, with NNRTI and NRTI aligning with the overall trend. The percentage of multidrug resistance was more than that of single-drug resistance in PDR and especially ADR annually. PDR was most prevalent in Central China followed by Southwest and North. ADR prevalence was highest in North China followed by Northwest and Southwest. In ADR sequences, high-level resistance was more common, especially in NRTI. PDR sequences exhibited low-level or intermediate resistance, especially PI. Drug resistance mutations revealed distinct patterns in PDR and ADR. CRF01_AE, the predominant subtype in China, exhibited the highest proportions among most ART drugs and drug resistance mutations, with a few exceptions where CRF07_BC (prominent in the Northwest), CRF55_01B and CRF08_BC (prominent in the Southwest) showed the highest proportions. HIV-1 PDR and ADR prevalence in China exhibited diverse epidemiological characteristics, underscoring the importance of ongoing national monitoring of PDR, ADR and subtype; patient education on adherence; and personalized regimens.

HIV-1 Molecular Networks and Pretreatment Drug Resistance at the Frontier of Yunnan Province, China.

The border areas of Yunnan Province in China are severely affected by human immunodeficiency virus (HIV). To investigate the risk of HIV transmission and assess the prevalence of pretreatment drug resistance (PDR) in the border area, blood samples were collected from individuals with newly reported HIV in 2021 in three border counties (Cangyuan, Gengma, and Zhenkang) in Yunnan Province. Among the 174 samples successfully genotyped, eight circulating recombinant forms (CRFs), two subtypes, and several unique recombinant forms (URFs) were identified. CRF08_BC (56.9%, 99/174), URFs (14.4%, 25/174), CRF01_AE (10.9%, 19/174), and CRF07_BC (8.0%, 14/174) were the main genotypes. CRF08_BC and URFs were detected more frequently in Chinese and Burmese individuals, respectively. CRF07_BC was found more frequently in men who have sex with men. The proportion of individuals detected in HIV-1 networks was only associated with case-reporting counties. When stratified by county, individuals aged ≤40 years in Cangyuan and ≥41 years in Gengma were more likely to be found in these networks. Furthermore, 93.8% (15/16) of the links in Cangyuan and 79.4% (50/63) of those in Gengma were located within their own counties. The prevalence of PDR to any antiretroviral drug, nucleoside reverse transcriptase inhibitors (NRTIs), and non-nucleoside reverse transcriptase inhibitors (NNRTIs) were 10% (17/170), 0.6% (1/170), and 9.4% (16/170), respectively. The most frequent resistance-associated mutations (RAMs) were V179D/VD/E/T (22.9%, 39/170) and E138A/G/K/R (13.5%, 23/170). In the molecular networks, six clusters shared common RAMs. HIV-1 genetics has become more diverse in border areas. HIV-1 molecular network analysis revealed the different characteristics of the HIV-1 epidemic in the border counties. The prevalence of PDR showed an upward trend, and the PDR to NNRTIs was close to the public response threshold. These findings provide information for the development of AIDS prevention and treatment strategies.

Full-Spectrum Surveillance of Pre-Treatment HIV Drug Resistance in Southeastern China.

HIV drug resistance compromises the ability of anti-retroviral therapy (ART) to suppress viral replication, resulting in treatment failure. This study investigates the prevalence of pre-treatment drug resistance (PDR) in newly diagnosed individuals in a prosperous city (Wenzhou) in Southeastern China. A cross-sectional investigation was carried out among 473 newly diagnosed ART-naive HIV-1-infected individuals between January and December 2022. The protease-reverse transcriptase (PR-RT) region and integrase (IN) region of HIV-1 were amplified by two separately nested PCRs, followed by sequencing. Drug resistance mutations (DRMs) and drug resistance to nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs) and integrase strand transfer inhibitors (INSTIs) were analyzed. The PDR prevalence was 6.5% [95% CI: 4.4-9.1] for any anti-retroviral drug, 0.9% [95% CI: 0.3-2.3] for NRTIs, 4.1% [95% CI: 2.5-6.5] for NNRTIs, 1.8% [95% CI: 0.8-3.6] for PIs and 0.5% [95% CI: 0.1-1.8] for INSTIs. According to the subtyping results of the PR-RT region, 11 different subtypes and 31 unique recombinant forms (URFs) were found. CRF07_BC was the dominant subtype (53.7%, 233/434), followed by CRF01_AE (25.3%, 110/434). V179D (1.6%) and K103N (1.4%) were the most predominant types of NNRTI DRMs. Q58E (1.2%) and M184V (0.7%) were the most frequent PI DRMs and NRTI DRMs, respectively. The INSTI-related DRMs Y143S (causes high-level resistance to RAL) and G163K (causes low-level resistance to EVG and RAL) were found in one patient each. Given the relatively high PDR prevalence of NNRTI (4.1%), non-NNRTI-based ART may be preferred in the future. It is recommended to include genotypic resistance testing before starting ART in regions where feasible.

Trends of pre-treatment drug resistance in antiretroviral-naïve people with HIV-1 in the era of second-generation integrase strand-transfer inhibitors in Taiwan.

Monitoring the trends of pre-treatment drug resistance (PDR) and resistance-associated mutations (RAMs) among antiretroviral-naïve people with HIV (PWH) is important for the implementation of HIV treatment and control programmes. We analysed the trends of HIV-1 PDR after the introduction of second-generation integrase strand-transfer inhibitors (INSTIs) in 2016 in Taiwan, when single-tablet regimens of non-nucleoside reverse-transcriptase inhibitor (NNRTI-) and INSTI-based antiretroviral therapy became the preferred treatments. In this multicentre study, we included newly diagnosed, antiretroviral-naïve PWH who underwent tests for RAMs between 2016 and 2022. Pre-treatment genotypic resistance testing was performed, along with HIV-1 subtyping and determinations of plasma HIV RNA load and CD4 lymphocyte counts. RAMs were analysed using the Stanford University HIV Drug Resistance Database and only RAMs conferring at least low-level resistance were included. From 2016 to 2022, pre-treatment blood samples from 3001 newly diagnosed PWH, which constituted 24.3% of newly diagnosed PWH in Taiwan during the study period, were tested. Of the PWH with analysable gene sequences, the HIV-1 PDR prevalence to NNRTIs, nucleoside reverse-transcriptase inhibitors (NRTIs), first- and second-generation INSTIs and PIs was 10.0%, 2.1%, 2.5%, 0.6% and 0.4%, respectively. While the trends of PDR remained stable for NRTIs, INSTIs and PIs, there was a significantly increasing trend of PDR to NNRTIs from 6.0% in 2016% to 13.1% in 2022 (P = 0.001). After the introduction of second-generation INSTIs in Taiwan, the trends of HIV-1 PDR to NRTIs and INSTIs remained low. Furthermore, there was no significant decrease of the prevalence of PDR toward NNRTIs between 2016 and 2022.

Epidemic trend, genetic characteristics, and transmission networks of HIV-1 among treatment-naive men who have sex with men in Hebei province, China.

Homosexual transmission has contributed greatly to the current HIV-1 epidemic in Hebei province, China. Dolutegravir (DTG) will be conditionally used as a component of free antiretroviral therapy (ART) according to manual for national free anti-AIDS treatment drugs (2023 edition) issued by China in June 2023. However, current genetic characteristics and pretreatment drug resistance (PDR) to proteinase inhibitors (PIs), reverse transcriptase inhibitors (RTs) and integrase strand transfer inhibitors (INSTIs) of HIV-1 in this population have remained unclear. Serial consecutive cross-sectional analyses for HIV- 1 infection trend, genetic characteristics, PDR and molecular transmission networks were conducted from 2018 to 2022. All of participants were HIV-1- infected MSM newly diagnosed at the HIV surveillance points (HSPs) in Hebei, China. Evidence of PDR was confirmed using the world health organization (WHO) list for surveillance of drug resistance mutations. In this study, a total of 14 HIV-1 subtypes were circulating in the HSPs of Hebei province, China. CRF01_ AE (51.9%, 350/675), CRF07_BC (30.4%, 205/675), B (6.2%, 42/675) and URFs (5.8%, 39/675) were the four most predominant subtypes among MSM. And, CRF07_BC (r > 0) and URFs (r > 0) indicated an increasing trend, respectively; however, CRF01_AE (r < 0) showed a decline trend. The overall prevalence of HIV-1 PDR showed a substantial increase from 6.3% in 2018 to 7.9% in 2022. The prevalence of NNRTI-PDR was the highest (5.8%, 39/675), followed by INSTIs (2.4%, 16/675), NRTIs (0.6%, 4/675) and PIs (0.3%, 2/675). Furthermore, extensive HIV-1 strains bearing PDR were circulating in the MSM population via molecular transmission networks for major HIV-1 subtypes, especially CRF01_AE and CRF07_BC. Our findings reflect that HIV-1 epidemic in the MSM population is complex and severe in Hebei, China. Therefore, it is urgent for us to implement more effective intervention measures to limit the further dissemination of HIV-1, especially the spread of HIV-1 INSTI-PDR strains.

Characteristics of genotype, drug resistance, and molecular transmission network among newly diagnosed HIV-1 infections in Shenzhen, China.

The HIV-1 pandemic has persisted for four decades, and poses a major challenge to global public health. Shenzhen, a city with large number of migrant populations in China, is suffering HIV-1 epidemic. It is necessary to continuously conduct the molecular surveillance among newly diagnosed HIV-1 patients in these migrant population. In this study, plasma samples of newly diagnosed and ART-naive HIV-1 infections were collected from Shenzhen city in China. The partial genes of HIV-1 gag and pol were amplified and sequenced for the analysis of genotype, drug resistance, and molecular transmission network. Ninety-one sequences of pol gene were obtained from newly diagnosed HIV-1 infections in Shenzhen, and seven HIV-1 subtypes were revealed in this investigation. Among them, the circulating recombinant form (CRF) 07_BC was the mostly frequent subtype (53.8%, 49/91), followed by CRF01_AE (20.9%, 19/91), CRF55_01B (9.9%, 9/91), unique recombinant forms (URFs) (8.8%, 8/91), B (3.3%, 3/91), CRF59_01B (2.2%, 2/91), and CRF08_BC (1.1%, 1/91). The overall prevalence of pretreatment drug resistance (PDR) was 23.1% (21/91), and 52.38% (11/21) of the PDR was specific for the nonnucleotide reverse transcriptase inhibitors (NNRTIs). Furthermore, a total of 3091 pol gene sequences were used to generate 19 molecular transmission clusters, and then one growing cluster, a new cluster, and a cluster with growth reactivation were identified. The result revealed that more sexual partner, CRF_07BC subtype, and seven amino acid deletions in gag p6 region might be the influencing factors associated with the high risk of transmission behavior. Compared with CRF01_AE subtype, CRF07_BC subtype strains were more likely to form clusters in molecular transmission network. This suggests that long-term surveillance of the HIV-1 molecular transmission should be a critical measure to achieve a precise intervention for controlling the spread of HIV-1 in China.

Age and CD4+ T cell counts are inversely associated with HIV drug resistance mutations in treatment naive female sex workers.

The increasing prevalence of human immunodeficiency virus (HIV) drug resistance mutations (HIVDRM) in untreated seropositive persons has consequences for future treatment options. This is extremely important in key populations such as female sex workers (FSWs), where the prevalence of pretreatment drug resistance (PDR) and associated risk factors are unknown. In this study, we analyzed PDR and associated risk factors in recently diagnosed and treatment-naive FSWs in Nairobi, Kenya. In this cross-sectional study, we used 64 HIV-seropositive plasma samples collected from FSWs between November 2020 and April 2021. To identify HIVDRM, the pol gene was amplified and genotyped using sanger sequencing. The effects of age, tropism, CD4+ T cell count, subtype, and location on HIVDRM counts were examined using Poisson regression. Overall, the prevalence of PDR was 35.9% (95% CI: 24.3-48.9), which was strongly influenced by K103N and M184V mutations, which confer resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs) and nucleoside reverse transcriptase inhibitors (NRTI), respectively. Subtype A1 was predominant followed by subtype D with a notable increase in inter-subtype recombinants. We found statistically significant evidence that age was inversely related to HIVDRM. A FSW who is 1 year older had 12% less HIVDRM (incidence rate ratios [IRR]: 0.88; 95% CI: 0.82-0.95; P < .001), after adjusting for CD4+ T cell count, subtype, location, and tropism. Similarly, an increase in CD4+ T cell count by 1 unit, was associated with 0.4% fewer HIVDRM (IRR: 0.996; 95% CI: 0.994-0.998; P = .001), while controlling for the other variables. HIV-1 tropism was not associated with HIVDRM counts. In conclusion, our findings show a high prevalence of NNRTIs. Lower CD4+ T cell counts and younger age were significant risk factors that influenced HIVDRM loads. This finding underscores the relevance of targeted interventions and the importance of continuing to focus on FSWs as a way of addressing the HIV epidemic.

Genetic Subtypes and Pretreatment Drug Resistance in the Newly Reported Human Immunodeficiency Virus-Infected Men Aged≥50 Years Old in Guangxi

Objective To analyze the genetic subtypes of human immunodeficiency virus (HIV) and the prevalence of pretreatment drug resistance in the newly reported HIV-infected men in Guangxi. Methods The stratified random sampling method was employed to select the newly reported HIV-infected men aged≥50 years old in 14 cities of Guangxi from January to June in 2020.The pol gene of HIV-1 was amplified by nested reverse transcription polymerase chain reaction and then sequenced.The mutation sites associated with drug resistance and the degree of drug resistance were then analyzed. Results A total of 615 HIV-infected men were included in the study.The genetic subtypes of CRF01_AE,CRF07_BC,and CRF08_BC accounted for 57.4% (353/615),17.1% (105/615),and 22.4% (138/615),respectively.The mutations associated with the resistance to nucleoside reverse transcriptase inhibitors (NRTI),non-nucleoside reverse transcriptase inhibitors (NNRTI),and protease inhibitors occurred in 8 (1.3%),18 (2.9%),and 0 patients,respectively.M184V (0.7%) and K103N (1.8%) were the mutations with the highest occurrence rates for the resistance to NRTIs and NNRTIs,respectively.Twenty-two (3.6%) patients were resistant to at least one type of inhibitors.Specifically,4 (0.7%),14 (2.3%),4 (0.7%),and 0 patients were resistant to NRTIs,NNRTIs,both NRTIs and NNRTIs,and protease inhibitors,respectively.The pretreatment resistance to NNRTIs had much higher frequency than that to NRTIs (2.9% vs.1.3%;χ2=3.929,P=0.047).The prevalence of pretreatment resistance to lamivudine,zidovudine,tenofovir,abacavir,rilpivirine,efavirenz,nevirapine,and lopinavir/ritonavir was 0.8%, 0.3%, 0.7%, 1.0%, 1.3%, 2.8%, 2.9%, and 0, respectively. Conclusions CRF01_AE,CRF07_BC,and CRF08_BC are the three major strains of HIV-infected men≥50 years old newly reported in Guangxi,2020,and the pretreatment drug resistance demonstrates low prevalence.

Prevalence of pretreatment drug resistance in persons initiating and reinitiating antiretroviral therapy in Sri Lanka: results from a national representative survey.

We conducted a nationwide cross-sectional study to estimate pretreatment drug resistance (PDR) prevalence in adults initiating ART in Sri Lanka following the WHO's recommendations. HIV drug resistance was determined on dried blood spots (DBSs) using population-based sequencing of the protease and reverse transcriptase genes and interpretation was based on Stanford HIVdb v9.0. Analyses were weighted to adjust for multistage sampling and genotypic failure rate. We used logistic regression to assess differences between groups. Overall, in 10% (15 of 150) of patients initiating ART, HIV drug resistance mutations were detected. The prevalence of resistance to NNRTI drugs efavirenz/nevirapine was 8.4% (95% CI 4.6-15.0) but differed among those reporting having prior antiretroviral (ARV) exposure (24.4%, 95% CI 13.8-39.5) compared with 4.6% (95% CI 1.6-12.8) for those reporting as being ARV naive (OR 4.6, 95% CI 1.3-16.6, P = 0.021). PDR to efavirenz/nevirapine was also nearly twice as high among women (14.1%, 95% CI 6.1-29.4) compared with men (7.0%, 95% CI 3.1-14.7) (P = 0.340) and three times high among heterosexuals (10.4%, 95% CI 2.4-35.4) compared with MSM (3.8%, 95% CI 1.1-12.7) (P = 0.028). NRTI PDR prevalence was 3.8% (95% CI 1.1-12.1) and no PI PDR was observed in the study. A high prevalence of efavirenz/nevirapine PDR was reported, especially in patients with prior ARV exposure, in women and those reporting being heterosexual. These findings highlight the need to fast-track the transition to the WHO-recommended dolutegravir-based first-line ART.

Disparity of HIV-1 Pretreatment Drug Resistance in Men Who Have Sex With Men and the Heterosexual Population in Guangxi, China.

The prevalence of human immunodeficiency type 1 (HIV-1) pretreatment drug resistance (PDR) in men who have sex with men (MSM) in Guangxi remains unclear, and its effect on antiretroviral therapy (ART) needs to be further studied. Individuals newly diagnosed with HIV in Guangxi from 2016 to 2020, which mainly included MSM and the heterosexual (HES) population, were recruited in this study. Pol sequences were sequenced to analyze PDR and construct a genetic network. The risk factors for PDR and the effect on ART were respectively analyzed. The PDR of MSM in Guangxi was 4.7% (34/716), consisting of nonnucleoside reverse transcriptase inhibitors (3.5%), protease inhibitors (0.8%), integrase strand transfer inhibitors (0.7%), and nucleoside reverse transcriptase inhibitors (0.4%), and lower than that of HES (9.3% [77/827]). The subtype was associated with PDR, and MSM was lower than HES (CRF01_AE: 3.0% vs 8.0%; CRF07_BC: 4.1% vs 7.2%). CRF55_01B (adjusted odds ratio [aOR], 3.35) was a risk factor for PDR in MSM, while CRF08_BC (aOR, 2.34) and older (aOR, 2.75) were risk factors for PDR in HES. Six of 18 (33.3%) PDR of MSM in the network connected to each other, lower than that of HES (61.1% [22/36]). CRF55_01B (aOR, 5.69) was a risk factor for PDR transmission in MSM, while CRF08_BC (aOR, 4.08) was a risk factor in HES. Pretreatment CD4+ T-cell count, age, infection route, and subtype were associated with recovery of CD4+ count and suppression of viral load. The prevalence of PDR was different between MSM and HES, which may be associated with subtype. Thus, the monitoring of subtype and PDR should be strengthened.

Effects of pretreatment HIV drug resistance on the virological response of HIV-infected patients after 3-year antiretroviral therapy

Objective: To investigate the impact of pretreatment drug resistance (PDR) on virological effect among HIV-infected patients having received antiretroviral therapy (ART) after three years. Methods: The baseline survey of PDR among HIV-infected patients was conducted in 2018, with a three-year follow up study. The clinic data and virological laboratory test variables were statistically analyzed. Results: Of the 2 433 participants, 41.6% (1 012/2 433) were aged between 18 and 34, 82.8% (2 015/2 433) were males, 46.9% (1 142/2 433) had education of high school or above, 22.4% (544/2 433) were farmers, 33.8% (823/2 433) were unmarried, 48.1% (1 169/2 433) were infected heterosexually and 41.3% (1 004/2 433) were with CRF07_BC. The prevalence of PDR was 4.5% (109/2 433). The prevalence of virological suppression failure (viral load ≥50 copies/ml) and drug resistance at three years follow up after ART was 8.1%(196/2 433) and 2.5%(60/2 433) respectively. The prevalence of virological suppression failure and drug resistance at three years follow up after ART were 18.3% (20/109) and 7.6% (176/2 324), and 4.6% (5/109) and 2.4% (55/2 324) among participants with PDR and non-PDR, respectively. The results of multivariate logistic regression model showed that illiteracy (aOR=3.26, 95%CI: 1.82-5.86), primary and junior high school education (aOR=1.54, 95%CI: 1.09-2.18), CD4+T lymphocyte count <200/μl (aOR=2.77, 95%CI: 1.75-4.37) and CD4+T lymphocyte count 200-499/μl (aOR=1.55, 95%CI: 1.10-2.18) at a three year follow up visit after ART, missed drugs in the past month (aOR=4.24, 95%CI: 2.92-6.17), and PDR (aOR=2.84, 95%CI: 1.67-4.85) were statistically significant with virological suppression failure on treatment. Conclusions: The prevalence of PDR in China at a low level currently, and the virological suppression failure rate is low after three years of ART. It is necessary to strengthen drug resistance monitoring of HIV-infected patients and pay attention to the influence of PDR on treatment effect.

Prevalence of Pretreatment HIV-1 Drug Resistance in Armenia in 2017-2018 and 2020-2021 following a WHO Survey.

The increased antiretroviral therapy (ART) coverage of patients in the absence of routine genotyping tests and in the context of active labor migration highlight the importance of HIV-1 drug resistance (DR) surveillance in Armenia. We conducted a two-phase pretreatment DR (PDR) study in 2017-2018 (phase I; 120 patients) and 2020-2021 (phase II; 133 patients) according to the WHO-approved protocol. The analysis of HIV-1 genetic variants showed high degrees of viral diversity, with the predominance of A6. The prevalence of any PDR was 9.2% in phase I and 7.5% in phase II. PDR to protease inhibitors was found only in 0.8% in phase II. PDR to efavirenz and nevirapine was found among 5.0% and 6.7% of patients in phase I, and 6.0% and 6.8% of patients in phase II, respectively. The prevalence of PDR to nucleoside reverse-transcriptase inhibitors decreased from 5.0% in phase I to 0.8% in phase II. In addition, we identified risk factors associated with the emergence of DR-male, MSM, subtype B, and residence in or around the capital of Armenia-and showed the active spread of HIV-1 among MSM in transmission clusters, i.e., harboring DR, which requires the immediate attention of public health policymakers for the prevention of HIV-1 DR spread in the country.

HIV-1 pretreatment drug resistance and genetic transmission network in the southwest border region of China

BackgroundHIV drug resistance increased with the widespread use of antiretroviral drugs, and posed great threat to antiretroviral therapy (ART). Pu’er Prefecture, lying in the southwest of Yunnan Province, China, borders Myanmar, Laos and Vietnam, is also the area where AIDS was discovered earlier, however, in which there has been no information on HIV drug resistance.MethodsA cross-sectional survey of pretreatment drug resistance (PDR) was conducted in Pu’er Prefecture in 2021. Partial pol gene sequences were obtained to analyze drug resistance and construct genetic transmission network. HIV drug resistance was analyzed using the Stanford University HIVdb algorithm.ResultsA total of 295 sequences were obtained, among which 11 HIV-1 strain types were detected and CRF08_BC (62.0%, 183/295) was the predominant one. Drug resistance mutations (DRMs) were detected in 42.4% (125/295) of the sequences. The prevalence of PDR to any antiretroviral drugs, nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs) were 10.8% (32/295), 9.5% (28/295), 1.0% (3/295) and 0.3% (1/295), respectively. The risk of PDR occurrence was higher among individuals with CRF01_AE strain types. HIV-1 molecular network was constructed, in which 56.0% (42/75) of links were transregional, and 54.7% (41/75) of links were associated with Lancang County. Among the sequences in the network, 36.8% (35/95) harbored DRMs, and 9.5% (9/95) were drug resistance strains. Furthermore, 8 clusters had shared DRM.ConclusionThe overall prevalence of PDR in this study was in a moderate level, but NNRTIs resistance was very approaching to the threshold of public response initiation. PDR was identified in the transmission network, and DRMs transmission was observed. These findings suggested that the consecutive PDR surveillance should be conducted in this region.

Pre-treatment Drug Resistance Could Impact the 96-Week Antiretroviral Efficacy in Treatment-Naive HIV-1–Infected Patients in Guangdong, China

Abstract Background With the high prevalence of pre-treatment drug resistance (PDR) and the potential impact to the virological inhibition, the detection of PDR was particularly necessary. This study aimed to determine the prevalence of PDR in Guangdong, China, and its impact on antiretroviral therapy (ART) in treatment-naive HIV patients. Methods A retrospective cohort study was conducted. A total of 1936 HIV-1–infected treatment-naive patients in the clinic of the infectious department, Guangzhou Eighth People’s Hospital, between August 2018 and December 2019 were assayed for PDR mutations before initiating ART. Patients with PDR mutations (PDR arm) were screened and compared with those without drug-resistant mutations (non-PDR arm). The rate of HIV-1 virologic failure (VF) and CD4+ T-cell counts of the 2 arms were compared at the 96th week after ART to evaluate the impact of PDR on the efficacy of ART. Results Pretreatment drug resistance was detected in 125 cases (6.46%) from the 1936 enrolled participants, most of which were resistant to non-nucleoside reverse transcriptase inhibitors (64.00%, 80/125). One hundred and eight of 125 completed the follow-up of 96 weeks (PDR arm). In this cohort, 52 patients whose ART regimen containing the resistant drug were grouped as con-PDR arm, and the remaining 56 patients whose ART regimen did not contain the resistant drug were grouped as non- con-PDR arm. A total of 125 patients without PDR were randomly selected as the control group (non-PDR arm), 112 of whom had completed the 96-week follow-up. At the 96th week after ART initiation, 7 patients (6.5%, 7/108) in the PDR arm and 1 patient (0.9%, 1/112) in the non-PDR arm developed VF, exhibiting a significant difference (χ 2 = 4.901, P = 0.029). Meanwhile, 3 patients (5.8%, 3/52) in the con-PDR arm developed VF; the rate was also higher than that in the non-PDR arm, but without a significant difference (χ 2 = 3.549, P = 0.095). The CD4+ T-cell count in the non-PDR arm increased more than the PDR arm (386.6 vs. 319.1 cells/μL, t = 2.448, P = 0.015) or the con-PDR arm (386.6 vs. 325.1 cells/μL, t = 1.821, P = 0.070) at 12 weeks after ART. However, no significant differences were observed in the CD4+ T-cell count from the 24th week after ART onward. Conclusions Pretreatment drug resistance was moderately prevalent in Guangdong, China, and could affect the antiretroviral efficacy during a 96-week observation period, indicating the need to closely monitor PDR before ART initiation.

Molecular transmission network of pretreatment drug resistance among human immunodeficiency virus-positive individuals and the impact of virological failure on those who received antiretroviral therapy in China.

ObjectivesWe investigated the prevalence of pretreatment drug resistance (PDR), the molecular transmission network among HIV-positive individuals, and the impact of virological failure on those who received antiretroviral therapy (ART) in China.MethodsBased on the World Health Organization (WHO) surveillance guidelines for PDR, a baseline survey and follow-up were conducted in 2018 and 2021, respectively. Demographic information and plasma samples were obtained from all participants. HIV pol gene region sequences were used to analyze the PDR and molecular transmission networks using the Stanford HIV database algorithm and HIV-TRACE, respectively. This study assessed the odds ratios (OR) of PDR to virological failure (viral load ≥ 50 copies/mL) after 3 years of ART using multivariable logistic regression.ResultsOf the 4,084 individuals, 370 (9.1%) had PDR. The prevalence of PDR to non-nucleoside reverse transcriptase inhibitors (5.2%) was notably higher than that to nucleoside reverse transcriptase inhibitors (0.7%, p < 0.001), protease inhibitors (3.0%, p < 0.001), and multidrug resistance (0.3%, p < 0.001). A total of 1,339 (32.8%) individuals from 361 clusters were enrolled in the molecular transmission network. Of the 361 clusters, 22 included two or more individuals with PDR. The prevalence of virological failure among HIV-positive individuals after 3 years of ART without PDR, those with PDR to Chinese listed drugs, and those with PDR to other drugs was 7.9, 14.3, and 12.6%, respectively. Compared with that in HIV-positive individuals without PDR, virological failure after 3 years of ART was significantly higher (OR: 2.02, 95% confidence interval (CI): 1.25–3.27) and not significantly different (OR: 1.72, 95% CI: 0.87–3.43) in individuals with PDR to Chinese listed drugs and those with PDR to other drugs, respectively. Missed doses in the past month were significantly associated with virological failure (OR, 2.82; 95% CI: 4.08–5.89).ConclusionThe overall prevalence of PDR was close to a high level and had an impact on virological failure after 3 years of ART. Moreover, HIV drug-resistant strains were transmitted in the molecular transmission network. These results illustrate the importance of monitoring PDR and ensuring virological suppression through drug adherence.