Improvement in the 95-95-95 Targets Is Accompanied by a Reduction in Both the Human Immunodeficiency Virus Transmission Rate and Incidence in China.

BACKGROUND: In 2016, China has implemented the World Health Organization's "treat all" policy. We aimed to assess the impact of significant improvements in the 95-95-95 targets on population-level human immunodeficiency virus (HIV) transmission dynamics and incidence. METHODS: We focused on 3 steps of the HIV care continuum: diagnosed, on antiretroviral therapy, and achieving viral suppression. The molecular transmission clusters were inferred using HIV-TRACE. New HIV infections were estimated using the incidence method in the European Centre for Disease Prevention and Control HIV Modelling Tool. RESULTS: Between 2004 and 2023, the national HIV epidemiology database recorded 2.99 billion person-times of HIV tests and identified 1 976 878 new diagnoses. We noted a roughly "inverted-V" curve in the clustering frequency, with the peak recorded in 2014 (67.1% [95% confidence interval, 63.7%-70.5%]), concurrent with a significant improvement in the 95-95-95 targets from 10-13-<71 in 2005 to 84-93-97 in 2022. Furthermore, we observed a parabolic curve for a new infection with the vertex occurring in 2010. CONCLUSIONS: In general, it was suggested that the improvements in the 95-95-95 targets were accompanied by a reduction in both the population-level HIV transmission rate and incidence. Thus, China should allocate more effort to the first "95" target to achieve a balanced 95-95-95 target.

Molecular transmission network analysis of newly diagnosed HIV-1 infections in Nanjing from 2019 to 2021.

OBJECTIVE: The objective of this study was to conduct a comprehensive analysis of the molecular transmission networks and transmitted drug resistance (TDR) patterns among individuals newly diagnosed with HIV-1 in Nanjing. METHODS: Plasma samples were collected from newly diagnosed HIV patients in Nanjing between 2019 and 2021. The HIV pol gene was amplified, and the resulting sequences were utilized for determining TDR, identifying viral subtypes, and constructing molecular transmission network. Logistic regression analyses were employed to investigate the epidemiological characteristics associated with molecular transmission clusters. RESULTS: A total of 1161 HIV pol sequences were successfully extracted from newly diagnosed individuals, each accompanied by reliable epidemiologic information. The analysis revealed the presence of multiple HIV-1 subtypes, with CRF 07_BC (40.57%) and CRF01_AE (38.42%) being the most prevalent. Additionally, six other subtypes and unique recombinant forms (URFs) were identified. The prevalence of TDR among the newly diagnosed cases was 7.84% during the study period. Employing a genetic distance threshold of 1.50%, the construction of the molecular transmission network resulted in the identification of 137 clusters, encompassing 613 nodes, which accounted for approximately 52.80% of the cases. Multivariate analysis indicated that individuals within these clusters were more likely to be aged ≥ 60, unemployed, baseline CD4 cell count ≥ 200 cells/mm3, and infected with the CRF119_0107 (P < 0.05). Furthermore, the analysis of larger clusters revealed that individuals aged ≥ 60, peasants, those without TDR, and individuals infected with the CRF119_0107 were more likely to be part of these clusters. CONCLUSIONS: This study revealed the high risk of local HIV transmission and high TDR prevalence in Nanjing, especially the rapid spread of CRF119_0107. It is crucial to implement targeted interventions for the molecular transmission clusters identified in this study to effectively control the HIV epidemic.

Hepatitis C virus subtype diversity and transmission clusters characteristics among drug users in Zhuhai, South China.

BACKGROUND: Hepatitis C virus (HCV) infection poses a major public health challenge globally, especially among injecting drug users. China has the world's largest burden of HCV infections. However, little is known about the characteristics of transmission networks among drug user populations. This study aims to investigate the molecular epidemiology and transmission characteristics of HCV infections among drug users in Zhuhai, a bustling port city connecting Mainland China and its Special Administrative Regions. METHODS: Participants enrolled in this study were drug users incarcerated at Zhuhai's drug rehabilitation center in 2015. Their sociodemographic and behavioral information, including gender, promiscuity, drug use method, and so forth, was collected using a standardized questionnaire. Plasmas separated from venous blood were analyzed for HCV infection through ELISA and RT-PCR methods to detect anti-HCV antibodies and HCV RNA. The 5'UTR fragment of the HCV genome was amplified and further sequenced for subtype identifications and phylogenetic analysis. The phylogenetic tree was inferred using the Maximum Likelihood method based on the Tamura-Nei model, and the transmission cluster network was constructed using Cytoscape3.8.0 software with a threshold of 0.015. Binary logistic regression models were employed to assess the factors associated with HCV infection. RESULTS: The overall prevalence of HCV infection among drug users was 44.37%, with approximately 19.69% appearing to clear the HCV virus successfully. Binary logistic regression analysis revealed that those aged over 40, engaging in injecting drug use, and being native residents were at heightened risk for HCV infection among drug user cohorts. The predominant HCV subtypes circulating among those drug users were 6a (60.26%), followed by 3b (16.7%), 3a (12.8%), 1b (6.41%) and 1a (3.85%), respectively. Molecular transmission network analysis unveiled the presence of six transmission clusters, with the largest propagation cluster consisting of 41 individuals infected with HCV subtype 6a. Furthermore, distinct transmission clusters involved eight individuals infected with subtype 3b and seven with subtype 3a were also observed. CONCLUSION: The genetic transmission networks revealed a complex transmission pattern among drug users in Zhuhai, emphasizing the imperative for a targeted and effective intervention strategy to mitigate HCV dissemination. These insights are pivotal for shaping future national policies on HCV screening, treatment, and prevention in port cities.

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.

[Analysis on the transmission characteristics of newly reported human immunodeficiency virus/acquired immunodeficiency syndrome cases based on the molecular transmission network in Huzhou, Zhejiang, 2017].

Objective: Using field epidemiological investigation and molecular analysis to construct the molecular transmission network of human immunodeficiency virus/acquired immunodeficiency syndrome cases (HIV/AIDS) newly diagnosed in Huzhou in 2017, Zhejiang Province. Methods: A total of 160 participants were obtained through a web-based system from Chinese Center for Disease Control and Prevention (CCDC) with the features of diagnosed in Huzhou in 2017 who also had been collected samples for the first follow-up. The basic information of demographic characteristics and risk factors was extracted from the website. RNA was extracted from plasma samples of untreated cases, followed by RT-PCR and nest-PCR for pol gene amplification, sequencing. Phylogenetic tree was constructed by MEGA software for HIV gene subtyping. TN93 model was used for calculating the distance between two sequences. Cytoscape software was used for drawing molecular transmission network. And then an epidemiological survey was conducted to cases in the primary cluster. Results: A total of 138 sequenced individuals (86.3%) were acquired from 160 individuals. Among which, 123 (89.1%) were male. The highest proportion of subtype was CRF07_BC (60, 43.5%), followed by CRF01_AE (46, 33.3%), and with four cases of Unique Recombinant Form (URF, CRF01_AE and CRF07_BC) and one case of URF (subtype B and C). A total of 18 molecular clusters included 56 individuals (40.6%) were found in the transmission network under the optimal genetic distance threshold (1.0%). The clustering proportion of CRF07_BC (66.1%, 37 cases) was higher than that of CRF01_AE. There were 9 clusters formed among CRF07_BC, including 37 cases (accounting for 61.7%, 37/60). The primary transmission cluster contained 11 cases, among which 9 cases were transmitted by homosexual sex. The first time of the cases to have homosexual behavior is range from 2010 to 2016, whose media number (P(25), P(75)) of partners was 6 (3.5, 8.5). Most of the cases come from Anhui Province and engaged in garment industry (5 cases), between which there were 8 cases used Blued software to seek for casual partners, 1 case seeking for casual partners in garden. Conclusion: With CRF07_BC and CRF01_AE predominantly circulating, HIV genetic diversity had been noticed in this area. The primary cluster was consisted of high proportion of locally new infections, and a specific population aggregation in limited place existed.

Exploring HIV-1 Transmission Features Among Older Individuals in Developed Eastern China.

The number of newly reported HIV-1 infections among older individuals (≥50 years of age) has increased rapidly in Hangzhou, a central city in the Yangtze River Delta region of China. To provide a scientific basis for prevention and intervention strategies targeted at older individuals in Hangzhou, an epidemiological survey combined with molecular transmission network analysis was conducted. A total of 2,899 individuals with newly confirmed HIV-1 infections, including 635 older individuals and 2,264 younger individuals (<50 years of age), were enrolled in this study. Among older individuals, heterosexual contact was the predominant mode of HIV-1 transmission. In addition, it was observed that older individuals with lower levels of education exhibited a higher susceptibility to HIV-1 infection. The analysis of transmission network, which was inferred using HIV-TRACE algorithm, revealed that the newly diagnosed HIV-1 infections among older individuals in Hangzhou exhibited a pattern of scattered transmission, with key clusters primarily located in non-main urban areas. The predominant mode of transmission in these areas was nonmarital and noncommercial or nonmarital and commercial heterosexual transmission. Notably, the study highlighted a significant proportion of older individuals (73.3%, 11/15) within B subtype. Multivariate logistic regression analysis further revealed that the subtype B was a significant factor associated with older individuals having ≥3 node degrees in the network, occurring 5.55 times more frequent than subtype CRF07_BC (95% confidence intervals = 1.17-26.22, p = .031). Furthermore, the lower CD4 levels observed among older individuals underscored the challenge of late diagnosis in Hangzhou. Taken together, it is imperative to test and intervene for high-risk older individuals. To tackle this issue effectively, it is essential to enhance the detection of the B subtype and implement targeted interventions in key clusters within non-main urban areas. In addition, proactive measures should be implemented to address the challenge of late diagnosis in Hangzhou by promoting widespread testing among the older individuals, particularly in priority areas.

Epidemic characteristics of local HIV-2 transmission across Hunan province, China.

OBJECTIVE: To elucidate the epidemiological features of HIV-2 in Hunan Province, China, utilizing sequence analysis. METHODS: Thirteen individuals diagnosed with HIV-2 infection in Hunan Province, China, from 2017 to 2023 were included in this study. Amplification of HIV-2 env and pol regions was conducted, followed by Sanger sequencing. Phylogenetic and molecular transmission network analyses were performed to delineate molecular features and transmission dynamics. RESULTS: All 14 individuals contracted HIV-2 through heterosexual intercourse, comprising 7 males and 7 females, with a median age of 58 years. Among them, three couples (HN001 and HN013, HN010 and HN011, HN008 and HN009) were identified, along with commercial sexual activity engagement reported for subject HN004. Notably, subjects HN001, HN003, HN008, and HN010 engaged in commercial sexual activities at the same location as subject HN004. Phylogenetic analysis of the pol gene revealed close proximity of sequences from all subjects to reference sequences from Gambia (Sub-type A). Employing a genetic distance threshold of 1.5 %, eight out of the 14 subjects formed a molecular transmission network, with HN002 and HN004 identified as central nodes. CONCLUSION: From 2017 to 2023, all HIV-2-infected individuals in Hunan Province, China, acquired the virus through identifiable routes, indicating transmission of similar HIV-2 strains among them.

Molecular Transmission Network and Drug Resistance in Treatment-Naive HIV-1-Infected Patients in the Liangshan District, China.

This study aimed to investigate the molecular transmission network and drug resistance in treatment-naive HIV-1-infected patients in the Liangshan District, China. The research subjects for this study were HIV-1-infected patients who did not receive any antiretroviral therapy (ART) in the Liangshan District between January 2022 and July 2023. Peripheral venous whole-blood samples were collected from the research subjects. Two milliliters of blood was used for CD4+ T lymphocyte counting detection. Ten milliliters of blood was centrifuged to separate the plasma and blood cells for quantitative detection of HIV-1 RNA and DNA and drug resistance testing of HIV-1. A total of 156 participants were included in this study (88 males and 68 females). The median age of the participants was 37 years. The findings revealed a positive correlation between the HIV-1 DNA and the HIV-1 RNA levels (r = 0.478, p < 0.001). However, a negative correlation was observed between the HIV-1 DNA levels and CD4+ T lymphocyte counts (r = -0.186, p = 0.020). Of the 156 participants, 145 were successfully tested for drug resistance of HIV-1 RNA and HIV-1 DNA simultaneously. Four cases failed the HIV-1 RNA drug resistance testing, and another two failed the HIV-1 DNA drug resistance testing. The most common HIV-1 subtype was the CRF07_BC recombinant. In this study, the overall incidence of transmitted drug resistance (TDR) was 8.33%. The resistance rates of non-nucleoside reverse transcriptase inhibitor (NNRTI) and protease inhibitor (PI) were 7.69% and 0.64%, respectively. In addition, 32 participants were found to have drug-resistant mutations. The primary drug-resistant mutations were K103N, V179D, E157Q, and A128T, mainly against efavirenz (EFV) and nevirapine (NVP) resistance. The drug resistance of HIV-1-infected ART-naive patients in the Liangshan District cannot be ignored. HIV-1 drug resistance testing is recommended before initiating ART.

Exploring Dynamic Changes in HIV-1 Molecular Transmission Networks and Key Influencing Factors: Cross-Sectional Study.

BACKGROUND: The HIV-1 molecular network is an innovative tool, using gene sequences to understand transmission attributes and complementing social and sexual network studies. While previous research focused on static network characteristics, recent studies' emphasis on dynamic features enhances our understanding of real-time changes, offering insights for targeted interventions and efficient allocation of public health resources. OBJECTIVE: This study aims to identify the dynamic changes occurring in HIV-1 molecular transmission networks and analyze the primary influencing factors driving the dynamics of HIV-1 molecular networks. METHODS: We analyzed and compared the dynamic changes in the molecular network over a specific time period between the baseline and observed end point. The primary factors influencing the dynamic changes in the HIV-1 molecular network were identified through univariate analysis and multivariate analysis. RESULTS: A total of 955 HIV-1 polymerase fragments were successfully amplified from 1013 specimens; CRF01_AE and CRF07_BC were the predominant subtypes, accounting for 40.8% (n=390) and 33.6% (n=321) of the specimens, respectively. Through the analysis and comparison of the basic and terminal molecular networks, it was discovered that 144 sequences constituted static molecular networks, and 487 sequences contributed to the formation of dynamic molecular networks. The findings of the multivariate analysis indicated that the factors occupation as a student, floating population, Han ethnicity, engagement in occasional or multiple sexual partnerships, participation in anal sex, and being single were independent risk factors for the dynamic changes observed in the HIV-1 molecular network, and the odds ratio (OR; 95% CIs) values were 2.63 (1.54-4.47), 1.83 (1.17-2.84), 2.91 (1.09-7.79), 1.75 (1.06-2.90), 4.12 (2.48-6.87), 5.58 (2.43-12.80), and 2.10 (1.25-3.54), respectively. Heterosexuality and homosexuality seem to exhibit protective effects when compared to bisexuality, with OR values of 0.12 (95% CI 0.05-0.32) and 0.26 (95% CI 0.11-0.64), respectively. Additionally, the National Eight-Item score and sex education experience were also identified as protective factors against dynamic changes in the HIV-1 molecular network, with OR values of 0.12 (95% CI 0.05-0.32) and 0.26 (95% CI 0.11-0.64), respectively. CONCLUSIONS: The HIV-1 molecular network analysis showed 144 sequences in static networks and 487 in dynamic networks. Multivariate analysis revealed that occupation as a student, floating population, Han ethnicity, and risky sexual behavior were independent risk factors for dynamic changes, while heterosexuality and homosexuality were protective compared to bisexuality. A higher National Eight-Item score and sex education experience were also protective factors. The identification of HIV dynamic molecular networks has provided valuable insights into the characteristics of individuals undergoing dynamic alterations. These findings contribute to a better understanding of HIV-1 transmission dynamics and could inform targeted prevention strategies.

Prevention and Control Are Not a Regional Matter: A Spatial Correlation and Molecular Linkage Analysis Based on Newly Reported HIV/AIDS Patients in 2021 in Jiangsu, China.

HIV-related spatial analysis studies in China are relatively few, and Jiangsu Province has not reported the relevant data in recent years. To describe the spatial distribution and molecular linkage characteristics of HIV-infected patients, this article combined descriptive epidemiology, spatial analysis, and molecular epidemiology methods to analyze patient reporting, patient mobility information, and HIV sequence information simultaneously. The results showed that HIV reporting profiles differed among Jiangsu cities, with the reporting rate in southern Jiangsu being above average. There was a spatial autocorrelation (Global Moran I = 0.5426, p < 0.05), with Chang Zhou showing a High-High aggregation pattern. Chang Zhou and Wu Xi were identified as hotspots for HIV reporting and access to molecular transmission networks. Some infected individuals still showed cross-city or even cross-province mobility after diagnosis, and three were linked with individuals in the destination cities within the largest molecular transmission cluster, involving 196 patients. The cross-city or cross-province mobility of patients may result in a potential HIV transmission risk, suggesting that combining timely social network surveys, building an extensive transmission network across cities and provinces, and taking critical regions and key populations as entry points could contribute to improved prevention and control efficiency and promote achievement of the 95-95-95 target and cascade.

The characteristics of HIV-1 subtype B on phylogenetic dynamic and molecular transmission network in Fuyang City, China, 2011 to 2019.

Introduction: HIV-1 subtype B, as once one of the earliest strains introduced into mainland China rapidly spread in commercial plasma donors and heterosexuals in 1990s. Here, we aim to investigate the origin and evolutionary history of HIV-1 subtype B in Fuyang city, China. Methods: We collected sequences tested from Fuyang in the east of China where higher prevalence of HIV-1 among commercial plasma donors and heterosexuals to construct a phylogenetic tree using the Markov chain Monte Carlo (MCMC) algorithm, infer molecular transmission network using TN93 model and visualize it with Cytoscape software. Results and discussion: Our results showed that >99% of subtype B sequences belonged to Thai B. The sequences from Fuyang often cluster closer to those from other its adjacent cities, which clustered together and formed a monophyletic cluster. HIV-1 B circulating in Fuyang dates back to approximately 1990. Among the 1,437 sequences, 166 clustered at a genetic distance of ≤1.2%, resulting in 73 clusters. The degree of clustering with at least one other person was 11.55%. Among the transmission clusters, 50 (80.65%) comprised two individuals. Most clusters consisted of both heterosexual transmission routes and men who have sex with men. Phylogenetic and molecular network analyses revealed a common origin with neighboring regions in mainland China, local onwards transmission after its introduction, and a limited clustering degree. However, at least two co-existing transmission routes in most transmission clusters imply a greater challenge in controlling the spread of HIV-1. Our findings highlight the value on tailoring prevention interventions by combination of molecular surveillance and epidemiology.

Using the Molecular Transmission Networks to Analyze the Epidemic Characteristics of HIV-1 CRF08_BC in Kunming, Yunnan.

HIV-1CRF08_BC is the most prevalent epidemic subtype among heterosexual (HET) and intravenous drug users (IDUs) in Kunming, Yunnan. Using the pol region of gene sequences derived from molecular epidemiological surveys, we developed a molecular transmission network for the purpose of analyzing its epidemiological characteristics, assessing its epidemiological trends, identifying its potential transmission relationships, and developing targeted interventions. HyPhy 2.2.4 was used to calculate pairwise genetic distances between sequences; GraphPad-Prism 8.0 was employed to determine the standard genetic distance; and Cytoscope 3.7.2 was applied to visualize the network. We used the network analysis tools to investigate network characteristics and the Molecular Complex Detection (MCODE) tool to observe the growth of the network. We utilized a logistic regression model to examine the factors influencing clustering and a zero-inflated Poisson model to investigate the factors influencing potential transmission links. At the standard genetic distance threshold of 0.008, 406 out of 858 study participants were clustered in 132 dissemination networks with a total network linkage of 868, and the number of links per sequence ranged from 1 to 19. The MCODE analysis identified three significant modular clusters in the networks, with network scores ranging from 4.9 to 7. In models of logistic regression, HET, middle-aged and elderly individuals, and residents of northern and southeastern Kunming were more likely to enter the transmission network. According to the zero-inflated Poisson model, age, transmission category, sampling year, marital status, and CD4+ T level had a significant effect on the size of links. The molecular clusters in Kunming's molecular transmission network are specific and aggregate to a certain extent. HIV-1 molecular network analysis provided information on local transmission characteristics, and these findings helped to determine the priority of transmission-reduction interventions.

Pretreatment HIV Drug Resistance and the Molecular Transmission Network Among HIV-Positive Individuals in China in 2022: Multicenter Observational Study.

BACKGROUND: Emerging HIV drug resistance caused by increased usage of antiretroviral drugs (ARV) could jeopardize the success of standardized HIV management protocols in resource-limited settings. OBJECTIVE: We aimed to characterize pretreatment HIV drug resistance (PDR) among HIV-positive individuals and risk factors in China in 2022. METHODS: This cross-sectional study was conducted using 2-stage systematic sampling according to the World Health Organization's surveillance guidelines in 8 provincial-level administrative divisions in 2022. Demographic information and plasma samples were obtained from study participants. PDR was analyzed using the Stanford HIV drug resistance database, and the Tamura-Nei 93 model in HIV-TRACE was used to calculate pairwise matches with a genetic distance of 0.01 substitutions per site. Logistic regression was used to identify and estimate factors associated with PDR. RESULTS: PDR testing was conducted on 2568 participants in 2022. Of the participants, 34.8% (n=893) were aged 30-49 years, 81.4% (n=2091) were male, and 3.2% (n=81) had prior ARV exposure. The prevalence of PDR to protease and reverse transcriptase regions, nonnucleoside reverse transcriptase inhibitors, nucleoside reverse transcriptase inhibitors, and protease inhibitors were 7.4% (n=190), 6.3% (n=163), 1.2% (n=32), and 0.2% (n=5), respectively. Yunnan, Jilin, and Zhejiang had much higher PDR incidence than did Sichuan. The prevalence of nonnucleoside reverse transcriptase inhibitor-related drug resistance was 6.1% (n=157) for efavirenz and 6.3% (n=163) for nevirapine. Multivariable logistic regression models indicated that participants who had prior ARV exposure (odds ratio [OR] 7.45, 95% CI 4.50-12.34) and the CRF55_01B HIV subtype (OR 2.61, 95% CI 1.41-4.83) were significantly associated with PDR. Among 618 (24.2%) sequences (nodes) associated with 253 molecular transmission clusters (size range 2-13), drug resistance mutation sites included K103, E138, V179, P225, V106, V108, L210, T215, P225, K238, and A98. CONCLUSIONS: The overall prevalence of PDR in China in 2022 was modest. Targeted genotypic PDR testing and medication compliance interventions must be urgently expanded to address PDR among newly diagnosed people living with HIV in China.

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.

Objectives: We 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. Methods: Based 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. Results: Of 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). Conclusion: The 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.

Identifying the Key Nodes of HIV Molecular Transmission Network Among Men Who Have Sex with Men - Guangzhou, Guangdong Province, China, 2015-2017.

WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?: Identifying the most influential spreaders in human immunodeficiency virus (HIV) transmission networks is crucial for developing effective prevention strategies. WHAT IS ADDED BY THIS REPORT?: This study identified key nodes of the HIV molecular transmission network among men who have sex with men (MSM) by utilizing linkages between sequences to reconstruct the transmission network at the molecular level. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE?: This study could act as an important supplement of laboratory results to epidemiological studies and suggests that interdisciplinary research could inspire new ideas for finding breakthroughs on HIV/acquired immunodeficiency syndrome (AIDS) prevention and control.

HIV-1 molecular transmission network among men who have sex with men in Shaoxing City / 预防医学

Objective@#To investigate the molecular transmission network characteristics of HIV-1 among men who have sex with men (MSM) in Shaoxing City, Zhejiang Province, so as to provide insights into AIDS prevention and control among MSM.@*Methods@#Newly reported HIV/AIDS cases among MSM in Shaoxing City were selected from January 2021 to September 2023. Plasma samples before the antiviral treatment were collected. The HIV-1 pol gene was amplified using reverse transcription PCR and nested PCR to construct phylogenetic trees for gene subtype analysis. The HIV-TRACE method was used to construct a molecular transmission network with a genetic distance of 1.5% to analyze clustering and the characteristics of cases within molecular clusters.@*Results@#A total of 216 HIV/AIDS cases among MSM were included, and 179 qualified sequences were obtained. The predominant HIV-1 subtypes were CRF07_BC and CRF01_AE, with 95 and 66 cases, respectively. At 1.5% genetic distance, 20 molecular clusters were formed, with 61 nodes and 58 edges. A total of 61 sequences were connected to the transmission network (34.08%). HIV/AIDS cases among MSM from all the counties (cities, districts) in Shaoxing City were included in the network. There was the largest molecular cluster with ≥10 nodes, involving 12 cases from five counties (cities, districts), 3 medium-sized molecular clusters with 4 to 5 nodes, and the 16 small-sized molecular clusters with 2 or 3 nodes. Seven cases with high risk of transmission, each with ≥4 edges, were all CRF07_BC subtypes. Among them, two cases were from the large molecular cluster, and five cases were from the same molecular cluster composed of cases from Shengzhou City and Xinchang County.@*Conclusions@#The predominant HIV-1 subtypes among MSM in Shaoxing City were CRF07_BC and CRF01_AE. There was cross-regional HIV transmission, and potential transmission risk might exist in Shengzhou City and Xinchang County.

HIV genotypes and molecular transmission networks among MSM with newly reported HIV infections in Dehong Prefecture， Yunnan Province from 2010 to 2019 / 上海预防医学

ObjectiveThis study aimed to investigate the HIV genotypic subtypes and molecular transmission clusters among men who have sex with men （MSM） with newly reported HIV infections in Dehong Dai and Jingpo Autonomous Prefecture （Dehong Prefecture）， Yunnan Province， China， between 2010 and 2019. The study aimed to identify potential high-risk transmitters and provide reference data for screening， management， and intervention of infection sources. MethodsPlasma samples from newly reported HIV-positive MSM individuals in Dehong Prefecture between 2010 and 2019 were collected. The viral pol gene fragments were amplified， sequenced， and genotyped. Genetic distances （GD） between pairwise sequences were analyzed and calculated. MEGA 7.0 and Gephi were used for phylogenetic and molecular transmission network analysis. ResultsA total of 159 newly reported HIV infections among MSM were included in the study， with successful genotyping of 100 cases. Nine HIV-1 subtypes were identified， with the most prevalent being CRF01_AE subtype （52%）， followed by CRF07_BC subtype （31%）， CRF55_01B subtype （10%）， and others （7%）. Cluster analysis revealed a total network access rate of 67%， forming three transmission clusters. CRF01_AE subtype formed two transmission clusters with 38 and 3 infected individuals， while CRF07_BC subtypes formed one transmission cluster with 26 infected individuals. The transmission network within the CRF01_AE clusters exhibited a more complex relationship. Significant differences in educational level were observed between the two main transmission clusters. ConclusionThe predominant HIV subtypes among newly reported MSM cases in Dehong Prefecture between 2010 and 2019 were CRF01_AE and CRF07_BC. Significant cultural differences are observed between the main transmission clusters. Continued monitoring of genotypic subtypes and targeted interventions within transmission clusters are warranted.

Molecular epidemiological characteristics of HIV-1 infection among men who have sex with men in Jiaxing City / 中华微生物学和免疫学杂志

Objective:To investigate the molecular epidemiological characteristics of HIV-1 infection among men who have sex with men (MSM) in Jiaxing city, and provide methods and ideas for the prevention and control of HIV-1 infection.Methods:This study retrospectively collected the blood samples from all newly reported cases of HIV-1 infection among MSM without antiviral treatment from 2020 to 2022. HIV-1 pol genes in the blood samples were amplified and sequenced. MEGA v6.0 software was used to analyze nucleic acid sequences. A phylogenetic tree was constructed to analyze HIV-1 subtypes. The calibrated population resistance program (CPR) was used to detect drug-resistant mutations. After calculating the genetic distance between gene sequences, molecular transmission networks were constructed using Cytoscape v3.6.0 software. Results:A total of nine genetic subtypes were identified, with CRF07_BC (43.3%) and CRF01_AE (36.9%) accounting for the most. The recombinant forms that were not clustered with the reference subtype accounted for 5.0%. Drug-resistant mutations were identified in 21 cases (7.0%), and the mutation rates among strains of CRF07_BC and CRF01_AE subtypes were 8.2% and 7.8%, respectively. The detection rates of drug-resistant mutations to protease inhibitors, nucleoside reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors were 1.7%, 0.7% and 4.7%, respectively. The optimal genetic distance threshold of the molecular network was 0.018. At this genetic distance, the molecular network access rate was 43.3%, and 38 molecular clusters (ranging from 2 to 26 nodes per cluster) were included. Cases with ≥6 homosexual partners and a degree value of ≥4 were more likely to access the active molecular cluster. The population of high-risk transmission cases with TNS>0.75 were mainly nonlocal residents and commercial service providers. The recombinant forms showed high similarity in sequences with the strains from other provinces.Conclusions:The distribution of HIV-1 subtypes in MSM in Jiaxing city was complex. Given the increasing detection rate of recombinant forms, the high transmission rate of drug-resistant mutations, and the active molecular clusters and high-risk transmission clusters mainly detected in nonlocal residents and commercial service providers, strengthened surveillance and intervention are needed.

Molecular transmission characteristics of HIV-1 in mountainous areas of southwest Zhejiang Province / 中华微生物学和免疫学杂志

Objective:To understand the molecular transmission characteristics of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome(AIDS) patients in the mountainous area of southwest Zhejiang Province(Lishui city).Methods:A total of 147 blood samples were collected from newly-diagnosed HIV-1 infected who received no antiviral therapy, and pol gene was amplified, followed by sequencing. MEGA6.0 software was used to construct phylogenetic tree and determine gene subtypes. HIVDB online was used to analyze drug resistance mutation, then the pairwise genetic distance(GD) was calculated and the opitimal threshold of GD was selected, finally the molecular transmission network was constructed by Cytoscape3.7.0 software. Chi-square or Fisher′s exact probability method was used for statistical analysis. Results:A total of 134 sequences were obtained successfully, and nine subtypes were detected. The dominant subtypes were CRF08_BC (34.33%, 46/134), CRF01_AE (29.85%, 40/134) and CRF07_BC (23.88%, 32/134). It also found that age, registered residence, education level and transmission route had significant differences in distribution of subtypes ( P<0.05). Nineteen drug resistance individuals were found, and the total drug resistance rate was 14.18% (19/134). The HIV-1 molecular transmission network was plotted based on 1.2% GD threshold. A total of 15 transmission clusters (cluster size ranging from 2 to 29) were found. The network access rate was 49.25% (66/134), mainly including male (75.76%, 50/66), heterosexual (81.82%, 54/66) and patientsrinfected with CRF08_ BC (50.00%, 33/66). A transmission cluster including two cases of female sex workers and seven cases of drug resistance was identified, in which the average age of the patients was 57.21 years old and the average degree value was 22.7, and the cases were mainly infected through heterosexual contact (96.55%, 28/29). The highest homology of the sequences in the cluster was in Yunnan. Conclusions:The HIV-1 subtypes were diverse in the mountainous area of southwest Zhejiang Province(Lishui city). Drug resistant transmission had reached a moderate epidemic level. There were molecular transmission clusters with the aggregation characteristics of elderly clients in specific regions. It was urgent to formulate and implement precise intervention strategies to curb the spread of HIV.