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

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


Introduction
In the past forty-three years, acquired immune deficiency syndrome (AIDS) caused by human immunodeficiency virus (HIV) has contributed to serious public health problem, public security, and the recession of economic and culture worldwide (Liu and Yuan, 2003).In developing countries, AIDS is still one of three global threats such as drinking water shortage, reduction of agricultural acreage and AIDS in the 21st century, threatening the survival of mankind.In 2022, the Joint United Nations Program on HIV and AIDS (UNAIDS) reported that 39 million people worldwide were living with HIV, 1.3 million people were newly infected with HIV and 630,000 died of AIDSrelated illnesses (UNAIDS, 2023).HIV-1 of two types (HIV-1 and HIV-2) is the most frequent strain which resulted in the rapid spread of AIDS nationwide.In order to achieve the goal of ending AIDS epidemic by 2030, global governments and scientists have taken many measures to control and prevent HIV epidemic since the first identification of AIDS in America, such as the development of diagnosis methods, three 95-95-95 targets (i.e., 95% of the people living with HIV know their status; 95% of diagnosed people on antiretroviral therapy (ART) and 95% of people receiving ART virally suppressed), the surveillance of HIV diversity, vaccine research and so on.
In order to reduce recent HIV infection and death related to AIDS, China has taken effective measures such as joint interventions, ART, and scale-up of diagnostic testing to control HIV epidemic, and made big progress (Han et al., 2021;Hao et al., 2022;Zhao et al., 2023).HIV infections through blood transfusions and blood products have been basically blocked (0.0% in 2020 to 2022), and injecting drug transmission (0.4% in 2022) and mother-to-child transmission (0.2% in 2022) have been effectively controlled (Han et al., 2021;Han, 2023).AIDS treatment coverage and treatment success rate have reached more than 90% (Zhao et al., 2023).However, sexual contact transmission has been the most common infection route, accounting for more than 95%, and HIV-1 has spread out of its original risk group into general population via sexual transmission.By the end of 2022, there were 1.223 million people living with HIV (PLWH) in China (Han, 2023).Although the situation of HIV epidemic remains at a low prevalence level in China, HIV/AIDS prevention and treatment in China are still facing the arduous task and many questions, such as complex HIV diversity, drug resistance mutations (DRMs) and so on, which may take great challenges to the development of HIV-1 diagnostic testing, viral load measurements, vaccine development, and ART (Joris et al., 2020).Similar to Chinese HIV epidemic situation, Hebei faces the same questions.Different from heterosexuals (72.0%) in China, homosexuals have become the most frequent transmission route of HIV-1 in Hebei, for example, the proportion (more than 65.0%) of men who have sex with man (MSM) among newly diagnosed cases in Hebei was significantly higher than national level (25.6%) in 2022 alone (Lu et al., 2018;Joris et al., 2020;Wang et al., 2021).
Due to the high mutation, replication rates, double infection and super-infection of HIV, HIV recombinant forms are being increasingly complex (Arshan et al., 2021).The Los Alamos HIV Sequence Database 1 indicated that up to now, at least 158 circulating recombinant forms (CRFs) have been confirmed globally, including 1 https://www.hiv.lanl.gov/components/sequence/HIV/crfdb/crfs.comp157 HIV-1 CRFs and one HIV-2 CRF.And, a large number of unique recombinant forms (URFs) are continually formed each year.Of 157 CRFs, more than 50 CRFs were identified in China, and they mainly distributed in the sexual contact population especially MSM (>40%).Particularly, the number of novel CRFs derived from Chinese sequences are rising rapidly after 2018, and three novel CRFs were confirmed among MSM in Hebei.Even, some CRFs recently identified contained drug resistance to anti-retroviral drugs (ARDs).
Since the initiation of Chinese "Four Frees and One Care" policy in 2004, 92.8% of PLWH have been initiating and receiving ART, and 97.0% have obtained the suppressed viral load ≦ 1,000 copies/mL as of 2022 (Zhao et al., 2023).However, approximately 3.0% of PLWH experienced ART failure, and HIV DRM was the main factor of ART failure.Even, HIV-1 low-level viraemia (50-1,000 copies/mL) has been the risk factor of ART failure, DRM and death (Lucas et al., 2018), accounting for approximately 5.0% of PLWH receiving ART.The prevalence of HIV DR corresponding to reverse transcriptase inhibitors (RTIs)-based first-line ART was higher than others among PLWH receiving ART (WHO, 2021).51.2% of 28,510 patients experiencing ART failure harbored HIV-1 DRM in 2021: the DR prevalence of nucleoside reverse transcriptase inhibitors (NRTIs), nonnucleoside reverse transcriptase inhibitors (NNRTIs) and lopinavi/ritonavir (LPV/r) was 27.4, 48.8 and 1.8%, respectively (Zhao et al., 2023).Among naïve HIV-infected individuals, the overall prevalence of DR indicated an upward trend from 2004 to 2022, with a slow elevation in annual percent change of 3.11% between 2004 and 2015, and a rapid increment in annual percent change of 11.17% between 2016 and 2022 (Liu et al., 2023).In Hebei, our previous study (Lu et al., 2017a) indicated that the prevalence of HIV-1 DR in patients experiencing ART failure and naïve ART was 51.9 and 55.9%, respectively.However, no systematic research on pretreatment DR (PDR) of integrase strand transfer inhibitors (INSTIs) in China has been reported.Therefore, there is growing concern that the increasing of HIV-1 PDR prevalence could decline the efficacy of ART, representing a threat to ending AIDS epidemic by 2030.
In this study, we analyzed HIV-1 near full-length pol sequences (NFLPs) of MSM newly diagnosed as HIV-1 infection at the HIV surveillance points (HSPs) in Hebei of China between 2018 and 2022 and the near full-length genomes sequences (NFLGs) of URFs.Based on these data, we evaluated (1) the recent prevalence and recombinant patterns of HIV-1 from 2018 to 2022 in Hebei, China; (2) HIV-1 PDR to proteinase inhibitors (PIs), NRTIs, NNRTIs and INSTIs, and (3) HIV-1 molecular transmission network.

Study design
Serial consecutive cross-sectional analyses for HIV-1 infection trend, genetic characteristics, HIV-1 PDR and molecular transmission networks were conducted from 2018 to 2022 in Hebei, China.

Participants
All of participants were MSM newly diagnosed as HIV-1 antibody positive at the HSPs in Hebei, China.A total of 758 MSM were enrolled in this study between 2018 and 2022, including 151 in 2018, 165 in 2019, 169 in 2020, 124 in 2021 and 149 in 2022.They were ART-naïve adolescents and adults.The participants should meet the below criteria: (a) Have homosexual contacts; (b) their ages are ≥15 years.We obtained written informed consent from the participants, and collected their blood samples and baseline information via face-to-face interviews in a private room at the HSPs of 11 municipal Centers for Disease Control and Prevention of Hebei province, China.

HIV-1 laboratory tests
HIV-1 antibody, CD4 cell counts, and recent infection testing 5 mL whole blood sample was collected from each participant.50 μL whole blood sample was used to test CD4 cell counts using a flow cytometry (Becton-Dickinson, Franklin Lakes, NJ, USA).For the testing related to HIV-1, blood plasma was separated from the remaining whole blood by centrifuging with a rotate speed of 3,000 rpm for five minutes.All participants were confirmed as HIV-1 infection by Western blot test (WB; MP Biomedical Asia Pacific Pte. Ltd., Singapore) between 2018 and 2022, respectively.
Raw original reaction sequences sequenced by gene-sequencing company were assembled, aligned and manual editing using Contig Express 9.1 and Bio-Edit 7.0 software, respectively.HIV-1 subtypes were preliminarily inferred using the online HIV Blast Microsoft, 2 followed by a neighbor-joining (N-J) phylogenetic tree based on NFLP gene 2 https://www.hiv.lanl.gov/content/sequence/BASIC_BLAST/basic_blast.htmlsequences using MEGA 7.0 with 1,000 bootstrap replicates.The reference sequences (A-D, F-H, J, K, O, CRF01_AE, CRFs_0107, CRFs_01C, CRFs_01B and others) were downloaded from the HIV database. 3And, subtypes were confirmed using the online REGA HIV-1 Subtyping Tool-Version 3.0.4For novel HIV-1 URFs based on the NFLPs, their NFLGs were further amplified and sequenced as previous method described by us (Yang et al., 2022).Their recombinant patterns were identified by the recombinant analysis of online jpHMM, online RIP 3.0 and simplot 3.5.1.

HIV-1 DR and genetic network analysis
HIV-1 NFLPs obtained from participants were submitted to HIV DR databases. 5Gene mutations resistant to PIs, NRTIs, NNRTIs and INSTIs were analyzed using HIVDB algorithm version 9.5.1 according to the world health organization (WHO) -recommended criteria for PDR.Moreover, DR level was classified as four categories, including potential low-, low-, intermediate-, and high-level resistance for different ARDs.
HIV-1 molecular transmission networks were constructed using the NFLPs data sources in Hebei province, China.Real-time transmission network analyses were performed using HYPHY2.2.4 and Cytoscape v3.8.0.Pairwise genetic distances were calculated using the Tamura-Nei 93 (TN93) model.A genetic distance threshold of 0.015 substitutions/site was selected to construct networks because this threshold is consistent with recent and rapid transmission.Molecular transmission networks were visualized using Cytoscape v3.8.0.

Statistical analysis
Statistical analysis was conducted using SPSS 23.0 (SPSS Inc.Chicago, IL, USA).Means or frequencies were used to summarize demographic data.Differences and the epidemic trend in categorical variables were analyzed using the chi-square (χ 2 ) test and χ 2 -trend, respectively.The pairwise test of independent variable in year and city was carried out using bonferroini method.All tests were two-sided p values and p-values <0.05 were considered statistically significant.Epidemic trend of HIV-1 subtypes with a p-value of 0.05 (χ 2 -trend) was analyzed using Spearman method: r < 0 denotes a negative correlation, and r > 0 denotes a positive correlation.

HIV-1 genotyping
As shown in Table 2, the HIV-1 epidemic in Hebei province was driven by 14 kinds of HIV-1 subtypes according to the overall analysis of HIV-1 NFLP and NFLG gene sequences, including 10 CRFs, three  Furthermore, the distribution of major subtypes showed no differences (χ 2 = 6.481, p = 0.166) between long-term infection and recent infection.Other subtypes indicated small-scale sporadic characteristics, and had a prevalence of ≤1.0%.The number of HIV-1 subtypes among MSM at the HSPs showed a significant increase from 6 in 2018 to 10 subtypes in 2022.And, new subtypes occurred each year (Table 2).Table 3 showed that CRF07_BC (r = 0.083, p = 0.034) and URFs (r = 0.145, p = 0.000) indicated an increasing trend, respectively; however, CRF01_AE showed a decline trend (r = −0.110,p = 0.005).Particularly, the proportion of URFs indicated an obvious increasing trend from 1.6% in 2018 to 7.2% in 2022.As presented in Figure 2 and Table 4, 44 NFLP-URFs were identified between 2018 and 2022.30 NFLGs from participants with 44 NFLP-URFs were successfully sequenced in order to confirm their recombinant forms.The recombinant structure analysis (Table 4; Figure 3) indicated that 3 of 30 NFLGs were identified as CRFs, including two CRF68_01Bs, two CRF80_0107s and one CRF65_cpx.The remaining 25 NFLG-URFs and 14 NFLP-URFs were confirmed as the real URFs in this study.

Discussion
In order to monitor the prevalence of HIV and influencing factors, analyze HIV epidemic trend, and evaluate the changing of HIV plague in the special populations in different areas, China has set up numerous HSPs nationwide.For our current work, HIV-1 epidemic Frontiers in Microbiology 08 frontiersin.org(1.9) trend, PDR and molecular transmission networks among ART-naïve MSM were investigated using five consecutive cross-sectional data obtained from the HSPs in Hebei Province, China.The primary observation from our investigation showed that 14 kinds of HIV-1 subtypes were circulating among MSM newly diagnosed at the HSPs in Hebei, including 10 CRFs, three simple subtypes and a proportion of URFs.Of these subtype strains, the proportion of HIV-1 recombinants was 93.5% (631/675), which is in accordance with overall data (80 to 99%) in China (Joris et al., 2020).CRF01_AE (51.9%),CRF07_BC (30.4%),B (6.2%), and URFs (5.8%, 39/675) were the four dominant subtypes circulating in the MSM population in Hebei, which shares similarities with that in China (Ye et al., 2022).
The study indicated that a total of 38 HIV-1 subtypes were identified in China (Ye et al., 2022).Of 38 subtypes, CRF01_AE (44.3%) was the most frequent subtype, followed by CRF07_BC (28.3%),B (13.9%) and URFs (5.9%) in the MSM population.However, the prevalence of HIV-1 subtypes in Hebei is significantly different from that in the western and southern provinces of China (Su et al., 2014;Zhang et al., 2022).Key data from our study illustrated that the prevalence of dominant HIV-1 subtypes had changed continually from 2018 to 2022 among MSM from the HSPs in Hebei: CRF07_BC (r = 0.083, p = 0.034) and URFs (r = 0.145, p = 0.000) indicated an increasing trend, respectively; however, CRF01_AE showed a decline trend (r = −0.110,p = 0.005).Furthermore, the distribution of these four major subtypes in long-term infection and recent infection was not different, and these four major subtypes were the source of recent HIV-1 infection.
The number of HIV-1 subtypes among MSM at the HSPs showed a significant increase from 6 in 2018 to 10 subtypes in 2022, and new subtypes occurred each year.Our study has unearthed a crucial finding regarding URFs: the proportion of URFs presented a rapid increasing trend from 1.6% in 2018 to 7.2% in 2022, and 1.2% of URFs were the recent infection.Moreover, as the dominant subtypes circulating in Hebei, CRF01_AE, CRF07_BC and B formed the essential architectures of URFs.In Hebei, MSM has overtaken other transmission routes and become the most predominant transmission pathway of HIV-1.Therefore, the above changes in the province level HIV-1 diversity among MSM at the HSPs illustrate a shift in homosexual risk behavior patterns and reflect HIV-1 epidemic trend in Hebei.
In our study, we analyzed HIV-1 PDR to PIs, NRTIs, NNRTIs and INSTIs and their changes among ART-naive MSM in 2018-2022.Particularly, the systematic research on the province level INSTI-PDR in Hebei was first conducted and analyzed.Our study showed that the overall prevalence of HIV-1 PDR among MSM at the HSPs in Hebei presented a substantial increase from 6.3% in 2018 to 11.8% in 2020, while a sharp decrease to 7.9% in 2022 was observed, which corresponded to a moderate level (5.0-15.0%)according to WHO threshold survey guidelines (Bennett et al., 2008).In contrast, a  First, the difference between different subtypes is analyzed using Chi square (χ 2 ) test.Further analysis will be carried out using Chi square for trend when a p-value (χ 2 -test) for HIV-1 subtype is less than 0.05.Lastly, we use Spearman method to analyze epidemic trend of HIV-1 subtypes with a p-value of 0.05 (χ 2 -trend): r < 0 denotes a negative correlation, and r > 0 denotes a positive correlation.p-values < 0.05 were considered statistically significant. 10.3389/fmicb.2024.1405565 Frontiers in Microbiology 10 frontiersin.orgnational research (Liu et al., 2023), which did not included INSTI-PDR, indicated that the overall prevalence of HIV-1 PDR showed an upward trend from 3.8% in 2016 to 6.9% in 2022 and a rapid increment in annual percent change of 11.17% were observed.Furthermore, the prevalence of HIV-1 PDR to NRTIs, PIs and NNRTIs showed the same epidemic pattern as the overall PDR in this study, respectively.To our knowledge, corona virus disease −19 started spreading in China at the end of 2019, and China government carried out large-scale prevention measures to control the spread of this novel virus throughout the whole country in 2020.We infer that prevention measures may disrupt the government's free ART plans and make some patients temporarily interrupt their treatment programs, leading to a rapid increase of DR mutations.Resistant strains begin to spread out of original groups into other populations such as treatment-naïve MSM once prevention measures are lifted, and HIV-1 PDR will decline with the process of ART normalization.
Our founding indicated that the prevalence of INSTI-PDR presented an increase from 2.3% in 2018 to 2.7% in 2019, while a sharp decrease to 0.9% in 2021 was observed, and then increased significantly to 3.6% in 2022.To put these findings in a global context, the prevalence of INSTI-PDR reported in our study was lower than some countries, such as Canada (8.0%) (Hezhao et al., 2018) and Cameron (5.1%) (Benjamin et al., 2021), but higher than estimates from Uganda (1.2%) (Suzanne et al., 2021) and Korea (2.4%) (Sang-Min et al., 2023).The result of a domestic preliminary investigation showed that there was a low prevalence (0.8%) of INSTI-PDR in some provinces of China in 2018 (Song et al., 2021).Moreover, the prevalence of INSTI-PDR reported in our study was higher than some areas, such as Guangxi (3.1%) (Yan et al., 2023), Beijing (0.62%) (Yu et al., 2022), Jiangsu (1.7%) (Yin et al., 2021), Guangzhou (1.49%) (Lan et al., 2022) and Nanjing (2.5%) (Wang et al., 2023), but lower than estimates from China's Yunnan (5.7%) (Deng et al., 2019), Taiwan (5.3%) (Chang et al., 2016) and Shenyang (3.7%) (Huang et al., 2019).And, all of INSTI mutation points were distributed in CRF01_AE and CRF07_BC, which significantly different from the distribution in subtypes A-G abroad (You et al., 2016).The prevalence of INSTI-PDR        presented an obvious increase in this situation, suggesting that effects of INSTIs will face an unprecedented severe challenge in the future.We found that a total of 48 transmission networks were circulating in the MSM population in Hebei, China.CRF01_AE was the most widespread subtype between cities, and CRF07_BC showed the strongest multi-city transmission.This study indicated that aged 25-49 years, cadre/staff/teacher, unmarried, minority, high school or below, initial CD4 counts >500 cells/μL, no STD history, homosexual partners ≥10, special survey, long-term infection, and drug resistance were associated with clustering in molecular transmission networks, and clustering frequency in this population was significantly related to CD4 counts, year and city.Furthermore, a substantial decrease was observed in clustering frequency from 37.5% in 2018 to 18.7% in 2022, with a concomitant increase in ART coverage from 78.7 to 91.1% over this period in Hebei, China.
However, 22.9% of 48 networks contained HIV-1 PDR mutations and 43.8% contained recently infected participants, and had a very strong transmission vitality.For example, five of seven major large networks (clusters 1-7) contained PDR mutations in this study, including two PI-mutation clusters, two INSTI-mutation clusters, one NNRTI and INSTI mutations clusters.And, recently HIV-1-infected individuals were circulating in four of five networks with PDR mutations.This suggests that CRF01_AE and CRF07_BC will be the most frequent HIV-1 strains in the MSM population in the future, and promote HIV epidemic of Hebei.
Compared with transmission links between Hebei and neighboring provinces proved by our previous reports (Lu et al., 2017b(Lu et al., , 2020;;Fan et al., 2022), our current work analyzed intracity and intercity transmission links of HIV-1 provincially.At the regional level, we found that the geographical distribution of clustering frequency was clustered in the central and northern part of Hebei, such as Qinhuangdao, Chengde, Baoding and Shijiazhuang.Six of seven large clusters with ≥5 participants were being in intercity links, with an apparent exception of cluster 3. The strongest intercity transmission for CRF07_BC was identified in Qinhuangdao-Baoding-Shijiazhuang-Cangzhou-Chengde-Tangshan.In cluster 3, strong intracity links for CRF07_BC were found in Qinhuangdao.The number of transmission networks identified in this study is not in accordance with the current level of HIV-1 epidemic in eleven cities of Hebei (Wang et al., 2021), which suggests that HIV-1 epidemic is growing rapidly in some cities with few HIV/AIDS cases, such as Qinhuangdao and Chengde.Although the success rate of ART indicated a significant increase from 95.0% in 2018 to 98.3% in 2022 according to our unpublished data, our findings show that HIV prevention and control will face severe challenges in the future.
Our current work has several limitations.First, the sample size in this study was limited because HIV/AIDS cases recently diagnosed were few at the HSPs in Hebei.Particularly, the precision of subtype distribution, PDR and network estimates in this area may be reduced due to the smaller sample size in some city such as Handan.Second, recent HIV-1 infection was tested only using HIV-1 LAg-Avidity, and recently HIV-1 infected MSM identified in our study were not confirmed again using the testing of HIV-1 viral load due to a fund shortage, which may be overestimate HIV-1 incidence.Lastly, only URFs were confirmed using NFLGs, however the most of HIV-1 subtype confirmation and the transmission network analysis were based on HIV-1 NFLPs, ignoring recombination within HIV-1 gag or env region.This may not reflect the actual HIV-1 subtype and intercity or intracity links of HIV-1 transmission.To minimize the above biases, longer gene fragments and more advanced methods to analyze HIV-1 subtypes, genovariation, and molecular transmission network are expected to improve the accuracy of study results later.

Conclusion
Our study demonstrated that a total of 14 HIV-1 subtypes were circulating in the HSPs of Hebei province, reflecting HIV-1 epidemic in the MSM population is complex and severe.CRF01_ AE, CRF07_BC, B and URFs were the four most predominant subtypes among MSM, and CRF07_BC and URFs indicated an increasing trend, respectively; however, CRF01_AE showed a decline trend.We analyzed HIV-1 PDR to PIs, NRTIs, NNRTIs and INSTIs, and found that the overall prevalence of HIV-1 PDR showed a substantial increase from 6.3% in 2018 to 7.9% in 2022.Furthermore, extensive HIV-1 strains bearing PDR were circulating in molecular transmission networks for major subtypes especially CRF01_AE and CRF07_BC.Therefore, it is urgent for us to implement more effective intervention measures to limit the further dissemination of HIV-1.

FIGURE 1
FIGURE 1 Geographic distribution of participants obtained from the HIV surveillance points in eleven cities of Hebei province, China.This figure was adapted from open access map: http://map.ps123.net/china/14.html with Microsoft PowerPoint 2016.In this figure, eleven areas denote all cities of Hebei province, including Zhangjiakou, Chengde, Qinhuangdao, etc. N denotes the number of participants.

FIGURE 2
FIGURE 2Phylogenetic tree based on HIV-1 near full-length pol gene sequences.The neighbor-joining tree was constructed based on HIV-1 near full-length pol sequences (NFLPs) identified in this study using MEGA 7.0.This figure identified all HIV-1 URFs which are based on NFLPs.Bootstrap values ≥70% are shown in the tree.The scale length indicates 2% nucleotide sequence divergence.Purple triangle, yellow inverted triangle, black dots, red square and pink dot denote participants identified in2018, 2019, 2020, 2021, and 2022,  respectively.

FIGURE 3
FIGURE 3Recombinant patterns of URFs based on HIV-1 near full-length genomes.The gene mosaic maps of HIV-1 near full-length genomes were analyzed using the online jpHMM (http://jphmm.gobics.de/).A, B, C and D denote the gene mosaic maps of novel recombinant forms found in 2019, 2020, 2021, and 2022, respectively.The number such as 9,115, 20,035 and so on denote sample ID.Other numbers listed in each gene map are gene recombinant breakpoints places.

FIGURE
FIGUREHIV-1 molecular transmission networks based on HIV-1 Near full-length pol gene sequences from all HIV-1 sequences identified in this study.There were 48 clusters in this study.There were seven large clusters containing 5 participants, including two CRF07_BC clusters (clusters 1 and 3), 5 CRF01_ AE clusters (clusters 2, and 4-7).Other clusters contained 2-4 participants.

TABLE 3
Epidemic trend of main HIV-1 subtypes circulating at the HSPs in Hebei province, China.

TABLE 4
Recombinant patterns of URFs based on HIV-1 near full-length pol genes and near full-length genomes.