The prevalence, temporal trends, and geographical distribution of HIV-1 subtypes among men who have sex with men in China: A systematic review and meta-analysis

Characterization of an Invisible HIV-1 Circulating Recombinant Form (CRF149_01B) in China

In this study, by analyzing the available near full-length genome (NFLG) sequences of CRF55_01B, it was found that two of the NFLG sequences could not be clustered with other NFLG sequences. Recombination analysis and phylogenetic analysis suggested that these two NFLG sequences arose by recombination with subtype B based on CRF55_01B, rather than by recombination directly derived from CRF01_AE and subtype B. In addition, two other HIV-1 partial gene fragments found in the database shared the same characteristics as these two NFLG sequences in the key recombination region. These sequences may therefore represent a previously unrecognized circulating recombinant form (CRF), which has been named CRF149_01B. Evolutionary analyses suggested that CRF149_01B emerged between approximately 2005 and 2007. The discovery of CRF149_01B highlights the complexity of HIV recombinant evolution and advances the refinement of the HIV genotyping system. A deeper understanding of HIV-1 genetics will facilitate molecular tracing and provide a basis for studying the biological properties of HIV.

HIV-1 drug resistance and genetic transmission networks among patients with sexually transmitted HIV in Ningxia, China

Background

Over the past decade, sexual transmission has become a dominant source of new HIV-1 infection in China. However, very few studies have been conducted to characterize the two sexual transmissions, homosexual and heterosexual transmission. This study was conducted to better understand the relationship between genotypes, drug resistance, and molecular transmission networks in two groups of sexually transmitted HIV-1 in Ningxia, China.

Methods

Plasma samples were collected from sexually transmitted HIV/AIDS patients in Ningxia between 2020 and 2021 for RNA extraction followed by HIV-1 genome sequencing, genotype and drug resistance analyses. The TN93 model in HyPhy2.2.4 with 1.25% as the threshold, was used to calculate the gene distance, and Cytoscape3.7.0 was used to generate a visual molecular transmission network.

Results

A total of 269 samples were successfully sequenced, and 10 HIV-1 subtypes were detected. The two most common subtypes were CRF07_BC and CRF01_AE. All 10 subtypes were detected in heterosexually transmitted patients, and 7 subtypes were found in homosexually transmitted patients who were exclusively men sex with men (MSM). The drug resistance rates of heterosexual individuals and MSMs were 45.34 and 33.33%, respectively. Sequences from 120 patients entered the molecular transmission network, forming 35 clusters. The clustering rate for MSM (52.78%) was higher than that of heterosexual individuals (39.13%). Some MSM and HSTs were involved in the same cluster and might act as bridges for transmission between the two populations.

Conclusion

Our data showed that heterosexually transmitted HIV-1 was more likely to be a drug-resistant virus, whereas MSM was more likely to contract viruses through network connection. It is strongly recommended that resistance testing be conducted before ART to improve effective treatment and reduce the spread of resistant viruses. Molecular networks can help to identify transmission clusters and provide more precise interventions.

Urban-rural disparity in risky sexual behavior, HIV knowledge, and healthy practices among men who have sex with men: A cross-sectional study in Southeast China

To identify differences in human immunodeficiency virus (HIV) risky behavior and healthy practices between rural and urban men who have sex with men (MSM) in Southeast China, a cross-sectional study was conducted on MSM aged ≥ 18 years recruited from four community-based organizations (CBOs) in seven cities in Zhejiang Province between October 2022 and March 2023. An electronic survey questionnaire was completed by the study participants to collect HIV risky behavior and healthy practices. The chi-square test and multiple logistic regression were used for analysis. Among the 1,993 MSM participants, 21.1% (420) were rural MSM. Compared with urban MSM, rural MSM was more likely to have a low level of education (high school and below; 46.2% vs. 40.2%, p = 0.028) and a low annual income (≤ 90,000 RMB; 71.2% vs. 64.7%, p = 0.013). Multiple logistic regression showed that, compared with urban MSM in the past 6 months behaviors, rural MSM had lower odds of finding casual sex partners on the Internet (adjusted odds ratio [aOR]: 0.790, 95% confidence interval [CI]: 0.633-0.986), using stimulants with online casual sex partners (aOR: 0.688, 95% CI: 0.506-0.936), and high odds of ever having sex with a female (aOR: 1.460, 95% CI:1.036-2.058). Rural MSM reported lower odds of an HIV knowledge score of 2-3 (aOR: 0.586, 95% CI: 0.454-0.756), HIV testing more than twice (aOR: 0.583, 95% CI: 0.455-0.748), and obtaining four to five types of HIV information (aOR: 0.661, 95% CI: 0.529-0.826), as well as higher odds of high/very high awareness of HIV infection risk (aOR: 2.312, 95% CI: 1.638-3.263), compared to urban MSM. Rural MSM and urban MSM reported discrepancies in HIV risky behavior, HIV knowledge and HIV-related healthy practices. Paying more attention to HIV risky behavior and improving healthy practices in rural areas may help to prevent HIV transmission.

The evolutionary and transmission dynamics of HIV-1 CRF08_BC

HIV-1 CRF08_BC is a significant subtype in China, though its origin and spread remain incompletely understood. Previous studies using partial genomic data have provided insights but lack comprehensive analysis. Here, we investigate the early evolutionary and spatiotemporal dynamics of HIV-1 CRF08_BC in China and Myanmar using near-complete genome sequences. We analyzed 28 near-complete HIV-1 CRF08_BC genomes from China and Myanmar (1997-2013). Phylogenetic, molecular clock, and Bayesian discrete trait analyses were performed to infer the virus's origin, spread, and associated risk groups. Based on Bayesian time-scaled inference with the best-fitting combination of models determined by marginal likelihood estimation (MLE), we inferred the time to the most recent common ancestor (TMRCA) and evolutionary rate of HIV-1 CRF08_BC to be at 3 October 1991 (95% HPD: 22 February1989-27 November 1993) and 2.30 × 10-3 substitutions per site per year (95% HPD: 1.96 × 10-3-2.63 × 10-3), respectively. Our analysis suggests that HIV-1 CRF08_BC originated in Yunnan Province, China, among injecting drug users, and subsequently spread to other regions. This study provides valuable insights into the early dynamics of HIV-1 CRF08_BC through combined genomic and epidemiological data, which may inform effective prevention and mitigation efforts. However, the limited genomic data influenced the extent of our findings, and challenges in collecting accurate risk group information during surveillance were evident.

Identification of the Near Full-Length Genome of a Novel HIV-1 CRF01_AE/CRF07_BC Recombinant in Hebei Province, China

To analyze the genetic structure and recombination characteristics of a newly discovered HIV-1 unique recombinant form (URF) isolated in Hebei Province, China, viral RNA was extracted from the plasma sample of the infected individual and reverse transcribed to cDNA. Two overlapping segments of the HIV-1 genome were amplified using a near-endpoint dilution method. Recombinant breakpoints were determined using RIP, jpHMM, and SimPlot 3.5.1 software. MEGA 6.0 software was used to construct a neighbor-joining phylogenetic tree. The near full-length genome sequence (8,862 bp) of a recombinant of CRF01_AE/CRF07_BC was obtained. The genome comprised at least seven overlapping segments, including four CRF01_AE and three CRF07_BC segments, with CRF01_AE as the backbone. A URF virus between CRF01_AE and CRF07_BC was amplified and characterized in this study. Parental viruses were homologous with HIV-1 strains prevalent among men who have sex with men in northern China and may originate from sexual transmission of local HIV-1 strains in Hebei Province.

The origin and spread of HIV-1 CRF59_01B epidemic in China: A molecular network and phylogeographic analysis

Human immunodeficiency virus type 1 CRF59_01B, identified in China in 2013, has been detected nationwide, exhibiting notably high prevalence in Guangzhou and its vicinity. This study aimed to unravel its origin and migration. A data set was established, incorporating all available CRF59_01B pol gene sequences and their metadata from Guangzhou and the public database. Bayesian phylogeographic analysis demonstrated that CRF59_01B originated in Shenzhen, the neighboring city of Guangzhou, around 1998 with posterior probability of 0.937. Molecular network analysis detected 1131 transmission links and showed a remarkably high clustering rate (78.9%). Substantial inter-city transmissions (26.5%, 300/1131) were observed between Shenzhen and Guangzhou while inter-region transmissions linked Guangzhou with South (46) and Southwest (64) China. The centre of Guangzhou was the hub of CRF59_01B transmission, including the inflow from Shenzhen (3.57 events/year) and outflow to the outskirts of Guangzhou (>2 events/year). The large-scale analysis revealed significant migration from Shenzhen to Guangzhou (5.08 events/year) and North China (0.59 events/year), and spread from Guangzhou to Central (0.47 events/year), East (0.42 events/year), South (0.76 events/year), Southwest China (0.76 events/year) and Shenzhen (1.89 events/year). Shenzhen and Guangzhou served as the origin and the hub of CRF59_01B circulation, emphasizing inter-city cooperation and data sharing to confine its nationwide diffusion.

Impact factors of Blastocystis hominis infection in persons living with human immunodeficiency virus: a large-scale, multi-center observational study from China

BACKGROUND

Blastocystis hominis (Bh) is zoonotic parasitic pathogen with a high prevalent globally, causing opportunistic infections and diarrhea disease. Human immunodeficiency virus (HIV) infection disrupts the immune system by depleting CD4+ T lymphocyte (CD4+ T) cell counts, thereby increasing Bh infection risk among persons living with HIV (PLWH). However, the precise association between Bh infection risk and HIV-related biological markers and treatment processes remains poorly understood. Hence, the purpose of the study was to explore the association between Bh infection risk and CD4+ T cell counts, HIV viral load (VL), and duration of interruption in antiviral therapy among PLWH.

METHODS

A large-scale multi-center cross-sectional study was conducted in China from June 2020 to December 2022. The genetic presence of Bh in fecal samples was detected by real-time fluorescence quantitative polymerase chain reaction, the CD4+ T cell counts in venous blood was measured using flowcytometry, and the HIV VL in serum was quantified using fluorescence-based instruments. Restricted cubic spline (RCS) was applied to assess the non-linear association between Bh infection risk and CD4+ T cell counts, HIV VL, and duration of interruption in highly active antiretroviral therapy (HARRT).

RESULTS

A total of 1245 PLWH were enrolled in the study, the average age of PLWH was 43 years [interquartile range (IQR): 33, 52], with 452 (36.3%) being female, 50.4% (n = 628) had no immunosuppression (CD4+ T cell counts > 500 cells/μl), and 78.1% (n = 972) achieved full virological suppression (HIV VL < 50 copies/ml). Approximately 10.5% (n = 131) of PLWH had interruption. The prevalence of Bh was found to be 4.9% [95% confidence interval (CI): 3.8-6.4%] among PLWH. Significant nonlinear associations were observed between the Bh infection risk and CD4+ T cell counts (Pfor nonlinearity < 0.001, L-shaped), HIV VL (Pfor nonlinearity < 0.001, inverted U-shaped), and duration of interruption in HARRT (Pfor nonlinearity < 0.001, inverted U-shaped).

CONCLUSIONS

The study revealed that VL was a better predictor of Bh infection than CD4+ T cell counts. It is crucial to consider the simultaneous surveillance of HIV VL and CD4+ T cell counts in PLWH in the regions with high level of socioeconomic development. The integrated approach can offer more comprehensive and accurate understanding in the aspects of Bh infection and other opportunistic infections, the efficacy of therapeutic drugs, and the assessment of preventive and control strategies.

Using HIV Risk Self-Assessment Tools to Increase HIV Testing in Men Who Have Sex With Men in Beijing, China: App-Based Randomized Controlled Trial

BACKGROUND

Men who have sex with men (MSM) in China hold a low-risk perception of acquiring HIV. This has resulted in an inadequate HIV testing rate.

OBJECTIVE

This study aims to investigate whether administering HIV risk self-assessments with tailored feedback on a gay geosocial networking (GSN) app could improve HIV testing rates and reduce sexual risk behaviors in Chinese MSM.

METHODS

We recruited MSM from Beijing, China, who used the GSN platform Blued in October 2017 in this 12-month double-blinded randomized controlled trial. From October 2017 to September 2018, eligible participants were randomly assigned to use a self-reported HIV risk assessment tool that provided tailored feedback according to transmission risk (group 1), access to the same HIV risk assessment without feedback (group 2), or government-recommended HIV education materials (control). All interventions were remotely delivered through the mobile phone-based app Blued, and participants were followed up at 1, 3, 6, and 12 months from baseline. The number of HIV tests over the 12-month study was the primary outcome and was assessed using an intention-to-treat analysis with an incident rate ratio (IRR). Unprotected anal intercourse (UAI) over 6 months was assessed by a modified intention-to-treat analysis and was the secondary outcome. All statistical analyses were conducted in SAS 9.3 (SAS Institute, Inc.), and a P value <.05 was considered statistically significant.

RESULTS

In total, 9280 MSM were recruited from baseline and were randomly assigned to group 1 (n=3028), group 2 (n=3065), or controls (n=3187). After follow-up, 1034 (34.1%), 993 (32.4%), and 1103 (34.6%) remained in each group, respectively. Over 12 months, group 1 took 391 tests (mean of 2.51 tests per person), group 2 took 352 tests (mean of 2.01 tests per person), and controls took 295 tests (mean of 1.72 tests per person). Group 1 had significantly more HIV testing than the control group (IRR 1.32, 95% CI 1.09-4.58; P=.01), while group 2 did not differ significantly from the controls (IRR 1.06, 95% CI 0.86-1.30; P=.60). The proportion of UAI was not statistically different among different groups, but all 3 groups had UAI, which declined from baseline.

CONCLUSIONS

Repeated HIV risk assessments coupled with tailored feedback through GSN apps improved HIV testing. Such interventions should be considered a simple way of improving HIV testing among MSM in China and increasing awareness of HIV status.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03320239; https://clinicaltrials.gov/study/NCT03320239.

Characterization of two novel HIV-1 second-generation recombinants (CRF01_AE/CRF07_BC) identified in Hebei Province, China

Introduction

The unique recombinant forms (URFs) of HIV-1 consist of a mixture of subtypes, and each URF has a unique breakpoint. In this study, we identified the near fulllength genome (NFLG) sequences of two novel HIV-1 URFs (Sample ID: BDD034A and BDL060) isolated during HIV-1 molecular surveillance in 2022 in Baoding city, Hebei Province, China.

Methods

The two sequences were aligned with subtype reference sequences and CRFs from China using MAFFT v7.0, and the alignments were adjusted manually using BioEdit (v7.2.5.0). Phylogenetic and subregion trees were constructed using MEGA11 with the neighbor-joining (N-J) method. Recombination breakpoints were identified by SimPlot (v3.5.1) based on Bootscan analyses.

Results

Recombinant breakpoint analysis revealed that the NFLGs of BDD034A and BDL060 were composed of CRF01_AE and CRF07_BC, containing seven segments, respectively. For BDD034A, three CRF01_AE fragments were inserted into the CRF07_BC main framework, whereas for BDL060, three CRF07_BC fragments were inserted into the CRF01_AE main framework.

Discussion

The emergence of the CRF01_AE/CRF07_BC recombinant strains indicates that HIV-1 co-infection is common. The increasing genetic complexity of the HIV-1 epidemic in China warrants continued investigation.

Identification of the Near Full-length Genome of a Novel HIV-1 CRF01_AE/CRF07_BC Recombinant with a Complex Genomic Structure Isolated in Hebei Province, China

BACKGROUND

During HIV genotypic drug resistance testing of patient samples in Baoding, Hebei Province, China, in 2022, a recombinant fragment was detected in the pol region of an HIV-1 strain.

OBJECTIVE

The objective of the study was to analyze the near full-length genome of a novel HIV-1 CRF01_AE/CRF07_BC recombinant with a complex genomic structure.

METHODS

Viral RNA was extracted from the blood of the infected individual and reverse transcribed to cDNA. Two overlapping segments of the HIV-1 genome were amplified using a nearendpoint dilution method and sequenced. Recombinant breakpoints were determined using RIP, jpHMM, and SimPlot 3.5.1 software. MEGA 6.0 software was used to construct a neighbor-joining phylogenetic tree.

RESULTS

We obtained the near full-length genome sequence (8680 bp) of a novel HIV-1 CRF01_AE/CRF07_BC recombinant. Recombination analysis showed that the genome comprised at least 12 overlapping segments, including six CRF07_BC and six CRF01_AE segments, with CRF07_BC as the backbone. The emergence of CRF01_AE/CRF07_BC recombinant strains indicated that HIV-1 co-infection is common. However, the increasing genetic complexity of the HIV-1 epidemic in China warrants continued investigation.

CONCLUSION

The increase in CRF01_AE/CRF07_BC recombinant viruses suggests that HIV-1 has a high genetic mutation rate in Hebei, China. This highlights the need for close monitoring of HIV-1 molecular epidemiologic changes to provide accurate, up-to-date information for effective disease control.

Young MSM changed temporal HIV-1 epidemic pattern in Heilongjiang Province, China

Background

Human immunodeficiency virus type 1 (HIV-1) epidemic in China is featured by geographical diversity of epidemic patterns. Understanding the characteristics of regional HIV-1 epidemic allows carrying out targeted prevention and controlling measures. This seven-year cross-sectional study was conducted in Heilongjiang, one province of Northeast China, where newly diagnosed infection is fast increasing yearly, but temporal HIV-1 epidemic trend is largely unknown.

Methods

Information of 1,006 newly diagnosed HIV-1-infected participants were collected before antiretroviral therapy during 2010-2016 in Heilongjiang province. HIV-1 genotype was identified based on the viral gag and env gene sequences. Recent infection was determined by Limiting-Antigen Avidity assays. Comparison analyses on the median ages, CD4 counts, proportions of stratified age groups and CD4 count groups, and rates of recent HIV-1 infection among different population and sampling times were performed to understand temporal HIV-1 epidemic features.

Results

Homosexual contact among men who have sex with men (MSM) was the main transmission route and CRF01_AE was the most dominant HIV-1 genotype. During 2010-2016, the HIV-1 epidemic showed three new changes: the median age continued to decline, the cases with a CD4 count more than 500 cells/μl (CD4hi cases) disproportionally expanded, and the recent HIV-1 infection rate steadily increased. MSM cases determined the temporal trend of HIV-1 epidemic here. Increase of young MSM cases (aged <30 years) made the main contribution to the younger age trend of MSM cases. These young MSM exhibited a higher median CD4 count, a higher proportion of CD4hi cases, and a higher rate of recent HIV-1 infection than cases aged 30 years and more. MSM infected by CRF01_AE virus mostly affected HIV-1 epidemic patterns among MSM population.

Conclusion

Young MSM have become a new hotspot and vulnerable group for HIV-1 transmission in Heilongjiang Province, Northeast China. The rapid increase in the number of young MSM cases, mainly those with CRF01_AE infection, changed temporal HIV-1 epidemic pattern here. Measures for prevention and control of HIV-1 infection among this population are urgently needed in the future.

An integrated online-to-offline model for HIV post-exposure prophylaxis (O2O-PEP) scale-up among men who have sex with men (MSM): Protocol for developing a pilot randomized controlled trial

Background

HIV post-exposure prophylaxis (PEP) is an evidence-based biomedical HIV prevention strategy consisting of a 28-day course of highly active antiretroviral therapy after recent potential exposure to HIV. However, awareness and uptake of PEP among men who have sex with men (MSM) are very low. Innovative and effective methods are needed to support PEP implementation among MSM. This work reports a protocol to design and evaluate an online-to-offline-based delivery model for HIV PEP uptake (O2O-PEP) in Chinese MSM.

Methods and analysis

This will be a two-phase study. In phase 1, we will develop an O2O-PEP model delivered through the WeChat mini-app (an app built into the WeChat platform). The O2O-PEP model initially includes four core components: a gamification-based education package for PEP, an online HIV risk assessment tool, a free online booking system for PEP initiation, and offline PEP prescription in the study hospitals. In phase 2, a two-arm pilot stratified randomized controlled trial comparing the O2O-PEP group with the standard care group will be designed to assess the feasibility, usability, and preliminary evidence of the efficacy of the O2O-PEP model in increasing PEP uptake among Chinese MSM. Model feasibility and usability will be further explored for broader model implementation.

Discussion

The O2O-PEP model is one of the first interventions in China aiming to promote PEP initiation in Chinese MSM. Components in the O2O-PEP model could assist MSM in better understanding their HIV infection risk and increasing accessibility of PEP. Moreover, coupled with online and offline recruitment, the O2O-PEP model has great potential to reach and engage MSM who are not involved in care by traditional methods.

Clinical trial registration

No. ChiCTR2200062538.

Identification of Three Novel HIV-1 Second-Generation Recombinant Forms (CRF01_AE/CRF07_BC) Among Men Who Have Sex with Men in Baoding, Hebei, China

The number of the second-generation recombinants originated from these two subtypes is significantly increasing due to co-circulating of CRF01_AE and CRF07_BC in China, especially among men who have sex with men (MSM). In this study, we reported three new unique recombinant forms (URFs) among MSM in Baoding, China. Phylogenetic and recombinant analyses based on the near full-length genome revealed these three URFs were the second-generation recombinant strains originated from CRF01_AE and CRF07_BC. Nowadays, the MSM has become a main route that causes the viral recombination. Therefore, the further epidemiological surveillance should be conducted in the MSM population to strengthen our knowledge of HIV-1 evolution and genetic diversity.

The Molecular Epidemiological and Immunological Characteristics of HIV-1 CRF01_AE/B Recombinants in Nanjing, China

Human immunodeficiency virus-type 1 (HIV-1) CRF01_AE/B recombinants are newly emerging strains that are spreading rapidly in Southern and Eastern China. This study aimed to elucidate the molecular epidemiological characteristics of HIV-1 CRF01_AE/B recombinants in Nanjing and to explore the impact of these novel strains on the immunological status. A total of 1,013 blood samples from newly diagnosed HIV-1-infected patients were collected in Nanjing from 2015 to 2019, among which 958 partial Pol sequences were sequenced successfully. We depicted the molecular epidemiological characteristics of CRF01_AE/B recombinants by the molecular evolutionary analysis, Bayesian system evolution analysis, and transmission network analysis. The generalized additive mixed model was applied to evaluate the CD4+ T-cell count change of CRF01_AE/B recombinants. The Kaplan–Meier analysis was performed to assess the time from combined antiretroviral therapy (cART) initiation to immune reconstruction. We have identified 102 CRF01_AE/B recombinants (102/958, 10.65%) in Nanjing, including CRF67_01B (45/102, 44.12%), CRF68_01B (35/102, 34.31%), and CRF55_01B (22/102, 12.57%). According to the Bayesian phylogenetic inference, CRF55_01B had a rapid decline stage during 2017–2019, while CRF67_01B and CRF68_01B have experienced a fast growth phase during 2014–2015 and then remained stable. We have constructed 83 transmission networks, in which three larger clusters were composed of CRF67_01B and CRF68_01B. CRF01_AE/B recombinants manifested a faster decrease rate of CD4+ T-cell count than CRF_07BC but similar to CRF01_AE. The probability of achieving immune reconstruction in CRF01_AE/B recombinants was lower than CRF07_BC in the subgroup of baseline CD4+ T-cell count at cART initiation &lt;300 cells/μl. In summary, CRF67_01B and CRF68_01B were the major strains of CRF01_AE/B recombinants in Nanjing, which have formed large transmission clusters between Nanjing and other provinces. CRF01_AE/B recombinants might be associated with rapid disease progression and poor immune reconstruction. The continuous epidemiological monitoring of CRF01_AE/B recombinants should be highly emphasized.

Enhanced Transmissibility and Decreased Virulence of HIV-1 CRF07_BC May Explain Its Rapid Expansion in China

HIV-1 CRF07_BC is one of the most common circulating recombinant forms (CRFs) in China and is becoming increasingly prevalent especially in HIV-infected men who have sex with men (MSM). The reason why this strain expanded so quickly in China remains to be defined. We previously observed that individuals infected with HIV-1 CRF07_BC showed slower disease progression than those infected with HIV-1 subtype B or CRF01_AE. CRF07_BC viruses carry two unique mutations in the p6Gag protein: insertion of PTAPPE sequences downstream of the original Tsg101 binding domain, and deletion of a seven-amino-acid sequence (30PIDKELY36) that partially overlaps with the Alix binding domain. In this study, we confirmed the enhanced transmission capability of CRF07_BC over HIV-1 subtype B or CRF01_AE by constructing HIV-1 transmission networks to quantitatively evaluate the growth rate of transmission clusters of different HIV-1 genotypes. We further determined lower virus infectivity and slower replication of CRF07_BC with aforementioned PTAPPE insertion (insPTAP) and/or PIDKELY deletion (Δ7) in the p6Gag protein, which in turn may increase the pool of people infected with CRF07_BC and the risk of HIV-1 transmission. These new features of CRF07_BC may explain its quick spread and will help adjust prevention strategy of HIV-1 epidemic. IMPORTANCE HIV-1 CRF07_BC is one of the most common circulating recombinant forms (CRFs) in China. The question is why and how CRF07_BC expanded so rapidly remains unknown. To address the question, we explored the transmission capability of CRF07_BC by constructing HIV-1 transmission networks to quantitatively evaluate the growth rate of transmission clusters of different HIV-1 genotypes. We further characterized the role of two unique mutations in CRF07_BC, PTAPPE insertion (insPTAP) and/or PIDKELY deletion (Δ7) in the p6Gag in virus replication. Our results help define the molecular mechanism regarding the association between the unique mutations and the slower disease progression of CRF07_BC as well as the quick spread of CRF07_BC in China.

Multiple CRF01_AE/CRF07_BC Recombinants Enhanced the HIV-1 Epidemic Complexity Among MSM in Shenyang City, Northeast China

The transmission of Unique Recombinant Forms (URFs) has complicated the molecular epidemic of HIV-1. This increasing genetic diversity has implications for prevention surveillance, diagnosis, and vaccine design. In this study, we characterized the HIV-1 URFs from 135 newly diagnosed HIV-1 infected cases between 2016 and 2020 in Shenyang, northeast China and analyzed the evolutionary relationship of them by phylogenetic and recombination approaches. Among 135 URFs, we found that the CRF01_AE/CRF07_BC recombinants were the most common (81.5%, 110/135), followed by CRF01_AE/B (11.9%, 16/135), B/C (3.7%, 5/135), and others (3.0%, 4/135). 94.8% (128/135) of patients infected by URFs were through homosexual contact. Among 110 URFs_0107, 60 (54.5%) formed 11 subclusters (branch support value = 1) and shared the consistent recombination structure, respectively. Four subclusters have caused small-scale spread among different high-risk populations. Although the recombination structures of URFs_0107 are various, the hotspots of recombinants gathered between position 2,508 and 2,627 (relative to the HXB2 position). Moreover, the CRF07_BC and CRF01AE fragments of URFs_0107 were mainly derived from the MSM population. In brief, our results reveal the complex recombinant modes and the high transmission risk of URFs_0107, which calls for more attention on the new URFs_0107 monitoring and strict control in the areas led by homosexual transmission route.

Genetic Characterization of a Novel HIV-1 Second-Generation Recombinant Form (CRF01_AE/CRF07_BC) Identified in Yan'an City, China

Owing to co-epidemic of CRF01_AE and CRF07_BC in China, increasing numbers of the second-generation recombinants between them have been identified especially among sexual population. In this study, we identified a unique CRF01_AE/CRF07_BC recombinants from a male HIV-1 positive individual (18YA004) infected by heterosexual contact in Yan'an city, Shaanxi province. The near full-length genome analyses showed 18YA004 was divided into six fragments by five breakpoints located in the pol, vpr, vpu, and nef gene, respectively. Three CRF01_AE segments (segments I, III, and V) were all clustered within the cluster 4a lineage, exclusively circulating among MSM in the northern China. Coupled with our previous finding of CRF01_AE/C recombinant in Yan'an city, the emergence of CRF01_AE/CRF07_BC strain further suggested coexistence of multiple HIV-1 genotypes here. Therefore, it is necessary to continue monitoring the molecular epidemiology of HIV-1 among high-risk groups to obtain a better understanding of the genetic complexity and transmission of HIV-1 in this region.

Using Molecular Transmission Networks to Reveal the Epidemic of Pretreatment HIV-1 Drug Resistance in Guangxi, China

Introduction

Pretreatment drug resistance (PDR) is becoming an obstacle to the success of ART. This study investigated the prevalence of PDR and the transmission clusters (TCs) of drug resistance mutations (DRMs) in two cities where drug abuse used to be high to describe the local HIV-1 transmission dynamics.

Methods

Plasma samples were obtained from 1,027 ART-naïve patients in Guangxi. Viral subtypes and DRMs were identified. Transmission network and related factors were also determined.

Results

A total of 1,025 eligible sequences were obtained from Qinzhou (65.8%) and Baise (34.2%) cities. The predominant HIV-1 genotype was CRF08_BC (45.0%), followed by CRF01_AE (40.9%). The overall prevalence of PDR was 8.3%, and resistance to NNRTI was the most common. Putative links with at least one other sequence were found in 543/1,025 (53.0%) sequences, forming 111 clusters (2–143 individuals). The most prevalent shared DRMs included V106I (45.35%), V179D (15.1%), and V179E (15.1%). Clusters related to shared DRMs were more frequent and larger in CRF08_BC. The prevalence of shared DRMs increased with time, while the proportion of PDR gradually decreased. Age > 50 years was associated with clustering. Subtype CRF08_BC was more likely to have DRMs, PDR propagation, and DRM sharing.

Conclusion

PDR prevalence is moderate in this region. The association between PDR and subtype CRF08_BC suggested that DRMs spreading from injection drug users (IDUs) to heterosexuals (HETs) might be the major source of PDR in this region. Our findings highlight the significance of continuous surveillance of PDR.

Evaluation of a novel in-house HIV-1 genotype drug resistance assay using clinical samples in China

Background

HIV drug resistance poses a major challenge for anti-retroviral treatment (ART) and the prevention and control of HIV epidemic.

Objective

The study aims to establish a novel in-house assay with high efficiency, named AP in- house method, that would be suitable for HIV-1 drug resistance detection in China.

Methods

An in-house HIV-1 genotyping method was used to sequence the partial pol gene from 60 clinical plasma samples; the results of our test were compared with a commercial ViroSeq HIV-1 genotyping system.

Results

Among sixty samples, 58(96.7%) were successfully amplified by AP in-house method, five of them harbored viral load below 1,000 copies/ml. The genotype distribution was 43.1% CRF07_BC (25/58), 39.7% CRF01_AE (23/58), 6.9% CRF55_01B (4/58), 5.2% subtype B (3/58) and 5.2% CRF08_BC (3/58). Compared with that of the ViroSeq system, the consistent rate of these nucleotides and amino acids obtained by AP in-house method was up to 99.5 ± 0.4% and 99.5 ± 0.4%, respectively. A total of 290 HIV-1 drug resistance mutations were identified by two methods, including 126 nucleoside reverse transcriptase inhibitors (NRTIs), 145 non-nucleoside reverse transcriptase inhibitors (NNRTIs) and 19 protease inhibitors (PIs) resistance mutations. Out of them, 94.1% (273/290) were completely concordant between the AP in-house method and the ViroSeq system.

Conclusion

Overall, the evaluation of AP in-house method provided comparable results to those of the ViroSeq system on diversified HIV-1 subtypes in China.

HIV-1 CRF07_BC transmission dynamics in China: two decades of national molecular surveillance

By analyzing an unprecedentedly large, longitudinal HIV-1 CRF07_BC sequence dataset collected from China in the past two decades, we sought to build CRF07_BC lengthwise transmission networks, and understand its transmission dynamics. We divided CRF07_BC into two clusters based on phylogenetic analysis and an estimation of the pairwise genetic distance at 0.7%. Of 6213 sequences, 3607 (58.1%) linked to ≥1 other sequence. CRF07_BC was divided into two clusters: 07BC_O and 07BC_N. The 07BC_O is the original CRF07_BC, circulating in people who inject drugs (PWID) and heterosexuals, predominantly in southwestern and northwestern provinces of China. The 07BC_N is a new cluster, identified mostly in men having sex with men (MSM) in the northern provinces of China. Bayesian analysis indicates that CRF07_BC has experienced two phases of exponential growth, which was first driven by 07BC_O then 07BC_N. Compared to 07BC_O, the proportion of the parameter of population transmission risk (TR) of 07BC_N has risen constantly. The power-law function analyses reveal that 07BC_N has increased over years with higher degree. In 07BC_N, only 13.16% of MSM were linked to other risk groups, but these links represent 41.45%, 54.25%, and 55.07% of links among heterosexual females, heterosexual males, and male PWID respectively. This study indicates that CRF07_BC has evolved into two clusters in China, and their distributions are distinct across risk groups and geographical regions. 07BC_N shows a greater risk of transmission, and has gradually replaced 07BC_O. Furthermore, the results show that strengthening the MSM interventions could lower the rapidity of 07BC_N transmission in all risk groups.

The prevalence of CRF55_01B among HIV-1 strain and its connection with traffic development in China

CRF55_01B is a relatively “young” HIV strain. At present, we do not know much about its transmission characteristics in China. So, to describe the transmission characteristics of CRF55_01B strain among provinces and HIV infected people, and to analyze the reasons for its rapid epidemic in China, a total of 1237 subjects infected with CRF55_01B from 31 provinces spanning a period of 12 years from 2007 to 2018 were enrolled in this study. By constructing a molecular network and Bayesian correlation analysis, we found that CRF55_01B increased exponentially from 2005 to 2009 after its origin in Shenzhen, and increased rapidly after 2010. CRF55_01B began to spread to other provinces in 2007. After 2010, the strain showed a trend of rapid spread and epidemic from Guangdong-Shenzhen to other provinces in China. Guangdong, Shenzhen, Hunan, Beijing, Guangxi, Hubei, Jiangxi, Guizhou, Hebei, Anhui, Shanghai, Shandong, Henan, and Yunnan were the key provinces of CRF55_01B transmission. CRF55_01B, although originating from men who sex with men (MSM), was transmitted among heterosexuals in 2010. Males in heterosexuals played a crucial role in the transmission and diffusion of this strain. We also revealed that CRF55_01B might spread rapidly along with the rapid development of the Beijing-Guangzhou and Beijing-Kowloon railways. This study suggests that if we detect the spread of MSMs in time through molecular monitoring in the early stage of the epidemic, it can help us control the epidemic early and prevent its spread, which is of great significance to China's national prevention and control of HIV-1.

The Emerging of CRF01_AE: A Clinical Story and Future HIV/AIDS Situation in Thailand

The HIV epidemic in Thailand in the 1980's compromised the country's socio-economic development. The epidemic first became evident in the community of men with male sexual partners (MSM), and subsequently spread to intravenous drug users (IVDU), female commercial sex workers (CSW) and their male clients, and, ultimately, to their partners and children. The HIV epidemic has devastated the country's working-age population. The extensive negative impact and social stigma associated with the disease do not only have an impact on the victims of HIV but also on their descendants and relatives. An epicenter of the HIV epidemic has been in the northern provinces of Thailand. An HIV-1 subtype CRF01_AE, a complex chimeric virus composed of both A and E subtypes, is prevalent in Northern Thailand. The virus has quickly become a predominant viral strain circulating in Thailand, other neighboring Southeast Asian countries, and China as well as some other countries throughout the world. The epidemiology, evolution, and biology of CRF01_AE offer a unique model for further scientific investigations which would advance the knowledge of and curative strategies against HIV. In addition, Thailand has developed suitable national guidelines on HIV/AIDS treatment and prevention in order to control the epidemic. Effective antiretroviral drugs are, therefore, able to be made available to those who live with HIV. The national surveillance system has also been effective. The great efforts and resources which Thailand has dedicated to the fight against the epidemic have eventually paid off. In 2010, a plan was proposed to eliminate mother-to-child HIV transmission and Thailand has become the first country to be effective in this objective. Thailand therefore has become recognized as being the global leader in HIV prevention and treatment. The experience which Thailand has gained from the past and the current research and management strategies of the HIV epidemic has prepared the country for emerging strains of HIV-1 in the future.

The Identification of A Novel HIV-1 Second-Generation Recombinant form (CRF01_AE/CRF07_BC) Among Men Who Have Sex with Men in Jiangsu, China

BACKGROUND

CRF01_AE and CRF07_BC are the two major HIV-1 virus strains circulating in China. The proportion of dominant subtypes (CRF01_AE and CRF07_BC) among MSM in Jiangsu province was over 80%. A large number of URFs have been found in China in recent years.

OBJECTIVE

This study aimed to report on novel HIV-1 recombinants.

METHODS

We constructed Phylogenetic trees using the maximum likelihood (ML) method with 1000 bootstrap replicates in IQ-TREE 1.6.8 software and determined recombination breakpoints using SimPlot 3.5.1.

RESULTS

We identified a novel, second-generation HIV-1 recombinant (JS020202) between CRF01_ AE and CRF07_BC. The analysis of near full-length genome (NFLG) showed there were at least 8 breakpoints in the virus, which differed from any previously identified CRF and URF around the world.

CONCLUSION

Novel diverse CRF01_AE/07_BC suggested the complexity trends of HIV-1 genetics. The emergency situation of diverse recombinant strains should be monitored continuously.

First Detection of a Cluster Novel HIV-1 Second-Generation Recombinant (CRF01_AE/CRF07_BC) among Men Who Have Sex with Men in Nanjing, Eastern China

INTRODUCTION

A large number of unique recombinant forms have been found in China in recent years. This study aimed to report on a cluster of novel HIV-1 recombinants.

METHODS

We constructed phylogenetic trees using the maximum likelihood (ML) method with 1,000 bootstrap replicates in IQ-TREE 1.6.8 software and determined recombination break points using SimPlot 3.5.1.

RESULTS

Overall, 9 near-full-length genome (NFLG) sequences were reported in this study, including 1 circulation recombinant form (CRF)01_AE NFLG sequence and 8 highly similar novel HIV-1 second-generation recombinants composed of CRF01_AE and CRF07_BC (CRF105_0107) isolated from a cluster HIV-positive male subjects infected among men who have sex with men (MSM) in Nanjing, eastern China. The phylogenetic analysis of NFLG showed 1 sequence named "nj16" to have at least 11 breakpoints inner virus and 7 other sequences to have at least 10 breakpoints inner virus. Our findings further showed as follows: first, this is the first time that a cluster of novel CRF105_0107 HIV-1 strains were identified among MSM in Nanjing, Jiangsu. Second, the Chinese "4a" cluster of CRF01_AE which mainly circulating in northern China has spread in Jiangsu for more than 15 years. Third, HIV-1 recombination events were active in Nanjing city, and novel recombinants could spread rapidly through some small-scale transmission networks.

CONCLUSION

The continued emergence of novel recombinant HIV-1 strains in Nanjing suggests dynamics and complexity in the HIV epidemic among MSM in Jiangsu province. Further investigations and molecular epidemiological research should be taken to monitor and understand transmission networks among MSM.

Risk assessment and identification of HIV infection among men who have sex with men: a cross-sectional study in Southwest China

OBJECTIVES

The HIV epidemic is around 7%-20% among men who have sex with men (MSM) in Southwest China. The low HIV-testing rate highlights the need for tools to identify high-risk MSM in resource-limited regions. Our aim was, therefore, to evaluate the HIV RISK Assessment Tool for HIV prediction and to characterise the primary infection among MSM in Southwest China.

DESIGN

A cross-sectional survey was conducted in Guizhou province between January and December 2018. Participants were recruited from gay communities, among whom the HIV RISK Assessment Tool was evaluated. Logistic regression was used to analyse items associated with HIV and the area under the curve (AUC) of the receiver operating curve was calculated to quantify discrimination performance.

PARTICIPANTS

1330 MSM participants, of which 83 (6.2%) tested as HIV positive.

RESULTS

A higher composite score of the tool (adjusted OR (aOR) 9.33, 95% CI 4.57 to 19.05) was independently associated with HIV infection. Items positively associated with HIV infection included having 2-5 same sex partners (aOR 2.43, 95% CI 1.28 to 4.64), always (aOR 5.93, 95% CI 1.59 to 22.13) or sometimes (aOR 4.25, 95% CI 2.09 to 8.64) having unprotected anal intercourse, taking both insertive and receptive sex roles (aOR 4.95, 95% CI 2.57 to 9.53) or only the receptive sex role (aOR 2.26, 95% CI 1.21 to 4.24). The tool showed an optimal discrimination ability (AUC=0.827), with a specificity of 0.747 and sensitivity of 0.785. Five MSM were identified with primary infection and had similar sexual risk behaviors as HIV-positive participants.

CONCLUSIONS

The HIV RISK Assessment Tool showed an overall good performance in predicting HIV risk among MSM in Guizhou province where the prevalence is still severe. This tool also demonstrated a potential to identify primary infection and is worth being promoted in resource-limited regions.

Comparative Circulation Dynamics of the Five Main HIV Types in China

The HIV epidemic in China accounts for 3% of the global HIV incidence. We compared the patterns and determinants of interprovincial spread of the five most prevalent circulating types. HIV pol sequences sampled across China were used to identify relevant transmission networks of the five most relevant HIV-1 types (B and circulating recombinant forms [CRFs] CRF01_AE, CRF07_BC, CRF08_BC, and CRF55_01B) in China. From these, the dispersal history across provinces was inferred. A generalized linear model (GLM) was used to test the association between migration rates among provinces and several measures of human mobility. A total of 10,707 sequences were collected between 2004 and 2017 across 26 provinces, among which 1,962 are newly reported here. A mean of 18 (minimum and maximum, 1 and 54) independent transmission networks involving up to 17 provinces were identified. Discrete phylogeographic analysis largely recapitulates the documented spread of the HIV types, which in turn, mirrors within-China population migration flows to a large extent. In line with the different spatiotemporal spread dynamics, the identified drivers thereof were also heterogeneous but are consistent with a central role of human mobility. The comparative analysis of the dispersal dynamics of the five main HIV types circulating in China suggests a key role of large population centers and developed transportation infrastructures as hubs of HIV dispersal. This advocates for coordinated public health efforts in addition to local targeted interventions.IMPORTANCE While traditional epidemiological studies are of great interest in describing the dynamics of epidemics, they struggle to fully capture the geospatial dynamics and factors driving the dispersal of pathogens like HIV as they have difficulties capturing linkages between infections. To overcome this, we used a discrete phylogeographic approach coupled to a generalized linear model extension to characterize the dynamics and drivers of the across-province spread of the five main HIV types circulating in China. Our results indicate that large urbanized areas with dense populations and developed transportation infrastructures are facilitators of HIV dispersal throughout China and highlight the need to consider harmonized country-wide public policies to control local HIV epidemics.

Genotypic Methods for HIV Drug Resistance Monitoring: The Opportunities and Challenges Faced by China

AIDS is a globalized infectious disease. In 2014, UNAIDS launched a global project of "90-90-90" to end the HIV epidemic by 2030. The second and third 90 require 90% of HIV-1 infected individuals receiving antiretroviral therapy (ART) and durable virological suppression. However, wide use of ART will greatly increase the emergence and spreading of HIV drug resistance and current HIV drug resistance test (DRT) assays in China are seriously lagging behind, hindering to achieve virological suppression. Therefore, recommending an appropriate HIV DRT method is critical for HIV routine surveillance and prevention in China. In this review, we summarized the current existing HIV drug resistance genotypic testing methods around the world and discussed the advantages and disadvantages of these methods.

Evolving HIV Epidemiology in Mainland China: 2009-2018

PURPOSE OF REVIEW

This review is intended to provide an overview of the evolution of HIV epidemiology over the past decade in China.

RECENT FINDINGS

We provided a succinct overall view of the epidemic, followed by surveillance data, profiles of key populations, HIV molecular epidemiology, and drug resistance, as well as survival in the age of antiretroviral therapy usage. For each topical issue, we first reviewed the latest empirical evidence, followed by a brief summary assessment. We briefly addressed the challenges and opportunities of the next generation of HIV control and prevention efforts in China. Notably, macro-social factors need to be integrated into the next generation of clinical and/or behavioral HIV research to inform disease progression and management, as well as control and prevention.

HIV-1 Drug Resistance, Distribution of Subtypes, and Drug Resistance-Associated Mutations in Virologic Failure Individuals in Chengdu, Southwest China, 2014-2016

The National Free Antiretroviral Therapy (ART) Program in China has initiated to provide ART to HIV-1 patients, which has acted as an efficient method to suppress viral replication and helps prevent onward transmissions. But the problems of HIV drug resistance (HIVDR) may also come along. There is little data on the prevalence of HIVDR in Chengdu, where the number of HIV/AIDS patients ranks first among provincial capitals. Therefore, epidemiological surveillance was conducted in this area. From 2014 to 2016, HIV/AIDS patients (15 years and older) who had received first-line ART for at least six months were enrolled. Demographic, behavioral information and medical history were recorded, and blood samples were collected for viral loads and immune cell count analyses. HIV-1 pol was obtained for HIV-1 subtypes and drug resistance-associated mutations (DRMs) among virologic failure patients. A total of 13,782 individuals were enrolled, and 481 samples were sequenced for subtypes and drug resistance analysis. Six subtypes were identified, among which CRF01_AE (54.3%) and CRF07_BC (41.6%) were the dominant subtypes, and CRF55_01B (0.4%) was detected in Chengdu for the first time. The prevalence of HIVDR in treatment-experienced patients was 1.8%, with 1.2% to nucleoside reverse transcriptase inhibitors (NRTIs), 1.7% to non-NRTIs (NNRTIs), and 0.14% to protease inhibitors (PIs). The leading DRMs observed in the study were M184I/V (59.59%) against NRTIs and K103N (37.55%) against NNRTIs. This study focused on the HIVDR surveillance among patients receiving treatment in Chengdu. The overall prevalence of HIVDR was relatively low among treated patients. These findings were believed to be contributed to an understanding of HIV-1 subtypes, HIVDR prevalence, and DRMs in Chengdu and thereby optimizing clinical management, prevention, and control of HIV.

App use frequency and condomless anal intercourse among men who have sex with men in Beijing, China: a cross-sectional study

Gay dating applications (apps) are popular among men who have sex with men (MSM) in China. This study examined the relationship between gay dating app use frequency and condomless anal intercourse (CAI) in a sample of MSM in Beijing. In October 2017, a web-based, cross-sectional survey was conducted among MSM from Beijing, China. Demographics, frequency of app use, and sexual behaviors were collected and analyzed. Multivariable logistic regression and restricted cubic splines were used to evaluate the association between app use frequency and CAI. Of the 9280 participants, the proportion of CAI within one month prior to the survey was 43.3%, and 43.7% logged onto the app ≥11 times per week. In adjusted logistic regression analysis, logging onto the app 6–10 times per week and ≥11 times per week were inversely associated with CAI (adjusted odds ratio [AOR] =0.88 [95%CI, 0.78–0.99]; AOR = 0.88 [95%CI, 0.82–0.97], respectively). Among those 40 years of age or older, logging onto the app ≥11 times per week was associated with lower rates of CAI (AOR = 0.57 [95%CI, 0.40–0.81]). Results indicate that frequent app use was associated with lower odds of CAI among MSM in Beijing, China. Innovative interventions, which take advantage of this popular media platform, should be developed as such apps have been found to reduce the odds of CAI in Beijing.