Identification of a new HIV-1 circulating recombinant form (CRF159_01103) derived from CRF103_01B and CRF01_AE in Hebei Province, China.

Recombinant HIV-1 genomes identified in three or more epidemiological unrelated individuals are defined as circulating recombinant forms (CRFs). CRFs can further recombine with other pure subtypes or recombinants to produce secondary recombinants. In this study, a new HIV-1 intersubtype CRF, designated CRF159_01103, isolated from three men who have sex with men with no epidemiological linkage, was identified in Baoding city, Hebei Province, China. CRF159_01103 was derived from CRF103_01B and CRF01_AE. Bayesian molecular clock analysis was performed on the CRF01-AE and CRF103_01B regions of CRF159_01103. The time of origin of CRF159_01103 was predicted to be 2018-2019, indicating that it is a recent recombinant virus. The emergence of CRF159_01103 has increased the complexity of the HIV-1 epidemic in Hebei Province.

Distribution pattern, molecular transmission networks, and phylodynamic of hepatitis C virus in China.

In China, few molecular epidemiological data on hepatitis C virus (HCV) are available and all previous studies were limited by small sample sizes or specific population characteristics. Here, we report characterization of the epidemic history and transmission dynamics of HCV strains in China. We included HCV sequences of individuals belonging to three HCV surveillance programs: 1) patients diagnosed with HIV infection at the Beijing HIV laboratory network, most of whom were people who inject drugs and former paid blood donors, 2) men who have sex with men, and 3) the general population. We also used publicly available HCV sequences sampled in China in our study. In total, we obtained 1,603 Ns5b and 865 C/E2 sequences from 1,811 individuals. The most common HCV strains were subtypes 1b (29.1%), 3b (25.5%) and 3a (15.1%). In transmission network analysis, factors independently associated with clustering included the region (OR: 0.37, 95% CI: 0.19-0.71), infection subtype (OR: 0.23, 95% CI: 0.1-0.52), and sampling period (OR: 0.43, 95% CI: 0.27-0.68). The history of the major HCV subtypes was complex, which coincided with some important sociomedical events in China. Of note, five of eight HCV subtype (1a, 1b, 2a, 3a, and 3b), which constituted 81.8% HCV strains genotyped in our study, showed a tendency towards decline in the effective population size during the past decade until present, which is a good omen for the goal of eliminating HCV by 2030 in China.

Three Novel CRF01_AE/CRF07_BC Recombinant Forms of HIV-1 Identified in Shijiazhuang City, China.

BACKGROUND: Hebei, a province with a low Human Immunodeficiency Virus (HIV) prevalence, is also a region with the most abundant HIV-1 genetic diversity. HIV-1 recombinant forms have been the key factor influencing the effectiveness of HIV-1 control and therapy. OBJECTIVES: We aimed to study inter-subtype recombinant structures of new HIV-1-second generation recombinant forms. METHODS: Monitoring the HIV-1 subtype by phylogenetic and recombinant breakpoint analyses are the two most frequent methods among men who have sex with men (MSM). Here, three near full-length genomes (NFLGs) were obtained from HIV-1 seropositive MSM in Shijiazhuang City, China, who have never received antiretroviral therapy in 2021. RESULTS: Phylogenetic analysis indicated that three NFLGs were novel inter-subtype recombinant forms between CRF07_BC and CRF01_AE. For the NFLG 21S009, four CRF07_BC gene fragments were inserted into the pol, vif-vpr, vpu-env, and nef-3` LTR gene regions within a CRF01_ AE backbone, respectively. For the NFLG 21S095, four breakpoints were identified in HIV-1 pol and vpu regions. The NFLG 21S370 contained four gene recombinant breakpoints within HIV-1 pol and vpu-env gene regions. Of these three NFLGs, the NFLG 21S009 contained the most breakpoints, distributed in the pol, vif, vpr, vpu, env, and nef regions, respectively. In the gag-pol regions, three NFLGs had only one CRF07_BC gene fragment inserted into gene points between 4250 and 4792. CONCLUSION: Our findings provide strong evidence that the surveillance of novel recombinant forms is necessary for the increase in better control of HIV.

Near-Full-Length Genome Analysis of a HIV-1 CRF01_AE/B Recombinant Strain Among Men Who Have Sex with Men in Chengde City, China.

The unique recombinant form (URF) of HIV is formed by multiple subtypes which are cocirculating in some area, and the number of HIV recombinants is on the increase worldwide. In this study, we identified a URF named 2019638, composed of CRF01_AE and subtype B, in a man who has sex with men in Qinhuangdao, Hebei province, China. The near-full-length genome (NFLG) sequence was confirmed to be a novel URF. Within this NFLG, two CRF01_AE fragments were inserted into the pol and vif regions, respectively, using subtype B as the backbone. Moreover, the presence of the V106M and V179D point mutations in the reverse transcriptase (RT) region rendered the high-level resistance to efavirenz and nevirapine and intermediate resistance to doravirine. Our findings suggest that the HIV epidemic is evolving toward a high degree of recombination, and we need to continuously monitor HIV genetic diversity to control the further development of the AIDS epidemic.

Changes of Viral Load, Drug Resistance, and CD4 Cell Count in HIV-1-Infected Patients Receiving Antiretroviral Therapy in Hebei Province, China, 2003-2019.

In this study, a total of 462 samples of whole blood were collected from 36 patients enrolled. During the entire course of antiretroviral therapy (ART) from 2003 to 2019, both the CD4 cell count and viral load (VL) of study patients were examined annually, and an HIV-1 genotypic drug resistance (DR) assay was carried out using an in-house method when the HIV-1 VL was >1,000 copies/mL. The results indicated that 13 (36.1%) experienced treatment failure and 23 (63.9%) experienced treatment success among 36 patients. The proportion of patients with effective treatment after the adjustment of ART regimens was significantly higher than before adjustment (χ2 = 33.796, p < .001). Furthermore, the frequencies of HIV-1 DR mutations before adjustment were higher than those after adjustment (t = 3.345, p = .002). In particular, among 23 patients with effective treatment after adjustment, the means ± standard deviations of the VLs and CD4 cell counts before adjustment were 3.85 ± 0.65 log RNA copies/mL and 226.83 ± 106.06 cells/mm3, respectively, compared with 2.19 ± 0.58 log RNA copies/mL and 367.68 ± 174.62 cells/mm3, respectively, after adjustment. Obviously, there were statistically significant differences in the changes in VL (t = 8.728, p < .001) and CD4 cell count (t = -4.476, p < .001) before and after adjustment. Therefore, patients who received updated ART regimens containing LPV/r and TDF after adjustment achieved better therapeutic effects compared with patients who received initial ART regimens harboring D4T/AZT or NVP. This suggests that future research is needed to initiate the surveillance of DR, VLs, and CD4 cell counts immediately after HIV diagnosis, and dynamic changes in these indicators so as to optimize ART effects.

Genome mosaic structure of two novel HIV-1 recombinant forms (CRF01_AE/B) in men who have sex with men in Hebei, China.

BACKGROUND: Homosexual contact is the main route of human immunodeficiency virus type one (HIV-1) transmission in Cangzhou Prefecture, Hebei, China. Moreover, the number of circulating recombinant forms (CRFs) and unique recombinant forms (URFs) in this key population is ever increasing. METHODS: In this study, we identified two novel URFs (hcz0017 and hcz0045) from two men who have sex with men (MSM) based in Cangzhou Prefecture. Phylogenetic and recombinant breakpoint analyses, based on the near full-length genomes (NFLGs) of the two novel URFs, showed that they originated from a recombination between HIV-1 CRF01_AE and subtype B. RESULTS: HXB2 numbering revealed that the NFLGs of hcz0017 and hcz0045 each contained the following seven subregions: hcz0017: IB (790-1,171 nt), IICRF01_AE (1,172-2,022 nt), IIIB (2,023-4,469 nt), IVCRF01_AE (4,470-5,866 nt), VB (5,867-7,462 nt), VICRF01_AE (7,463-8,379 nt), VIIB (8,380-9,411 nt); hcz0045: ICRF01_AE (790-5,147 nt), IIB (5,148-5,614 nt), IIICRF01_AE (5,615-6,035 nt), IVB (6,036-6,241 nt), VCRF01_AE (6,242-7,325nt), VIB (7,326-8,254 nt), VIICRF01_AE (8,255-9,411 nt). Moreover, the two MSM from whom the novel URFs originated from were diagnosed as recently HIV-1-infected, suggesting that the high prevalence of HIV-1 among MSM was related to high-risk sexual activity such as unprotected anal sex and multiple sexual partners. CONCLUSIONS: Our results highlight the need to continually monitor HIV-1 diversity in Hebei and its neighboring provinces to achieve a more effective control of HIV-1 spread within the MSM community.

Identification of two near-identical novel HIV-1 unique recombinant forms (CRF01_AE/B) among men who have sex with men in baoding, hebei, China.

Men who have sex with men (MSM) are the most frequent infection route of the human immunodeficiency virus (HIV) in Baoding, China, creating chances for the occurrence of unique recombinant forms (URFs) of the virus, i.e., recombination of different subtypes caused by co-circulation of multiple subtypes. In this report, two near-identical URFs (BDD002A and BDD069A) isolated from MSM in Baoding were identified. Phylogenetic tree analysis based on nearly full-length genomes (NFLGs) revealed that the two URFs formed a distinct monophyletic cluster with a bootstrap value of 100%. Recombinant breakpoints analysis identified that the NFLGs of BDD002A and BDD069A were both composed of CRF01_AE and subtype B, with six subtype B mosaic segments inserted into the CRF01_AE backbone. The CRF01_AE segments of the URFs clustered closely with the CRF01_AE reference sequences, and the B subregions clustered with the B reference sequences. The recombinant breakpoints of the two URFs were almost identical. These results suggest that effective interventions are urgently needed to prevent the formation of complex HIV-1 recombinant forms in Baoding, China.

Recombinant characteristics of three novel HIV-1 second-generation recombinant forms composed of CRF01_AE and CRF07_BC isolated in Hebei province, China.

Human immunodeficiency virus 1 (HIV-1) is a fast-evolving, genetically diverse virus. The HIV-1 evolution rate is also significantly influenced by the frequency of HIV-1 spread in a population. Transmission via homosexual contact has become the predominant transmission route, leading to an increase in the HIV-1 epidemic in Hebei province, China. In this study, we report three novel HIV-1 CRF01_AE/CRF07_BC recombinant forms isolated from three men who have sex with men (MSM) in the cities of Shijiazhuang (20747) and Langfang (20809 and 20820). Phylogenetic analysis based on HIV-1 near-full-length genome (NFLG) sequences indicated that the three novel recombinant forms formed a distinct monophyletic branch that was separate from all known HIV-1 subtypes and circulating recombinant forms (CRFs). Breakpoint analysis showed that the three NFLGs displayed different recombinant patterns. NFLGs 20747 and 20809 had a recombinant pattern with subtype CRF01_AE gene fragments inserted into a CRF07_BC backbone, spanning from the gag to env gene regions, whereas NFLG 20820 had a recombinant pattern with subtype CRF07_BC gene fragments inserted into a CRF01_AE backbone. Subregion phylogenetic analysis confirmed that these three NFLGs comprised CRF01_AE and CRF07_BC. Our findings confirm the emergence of novel recombinant forms and highlight the need for continuous monitoring of the diversity of HIV-1 among sexually active populations, especially MSM, to better control the HIV-1 epidemic.

Near-Full-Length Genomic Characteristics of Three Novel Human Immunodeficiency Virus-1 CRF01_AE/C Recombinant Forms Among Men Who Have Sex with Men in Hebei Province, China.

Subtypes circulating recombinant form (CRF)01_AE and C are two human immunodeficiency virus (HIV)-1 strains that are prevalent in different key populations such as men who have sex with men (MSM) in China. Co-circulating of different HIV-1 subtypes is easy to result in the generation of second-generation recombinants. In this study, three new HIV-1 CRF01_AE/C recombinants from three MSMs were detected in Hebei province, China. Phylogenetic tree and recombination analysis showed that the near-full-length genomic of S114 had seven recombination breakpoints, including four C fragments inserted into the CRF01_AE backbone; M363 had six recombination breakpoints, including three C fragments inserted into the CRF01_AE backbone; M162 had eight recombination breakpoints, including four C fragments inserted into the CRF01_AE backbone. Furthermore, phylogenetic tree analysis based on subregion gene fragments also identified this kind of CRF01_AE/C recombinant structure. This study suggests a more complex HIV-1 epidemiological trend in Hebei province, China and the urgency of continuous HIV-1 recombinant strain registry in sexually transmitted populations.

Identification of Two Novel HIV-1 Recombinant Forms Originated from CRF01_AE and Subtype B in the Sexual Contact Population in Hebei Province, China.

Two near full-length genome (NFLG) sequences of HIV-1 with undefined subtypes were analyzed to confirm the recombinant characteristics. To analyze the gene recombination patterns and breakpoints of these two NFLGs, the phylogenetic trees based on the NFLG sequences and their subregions were constructed, respectively. Sequences 233 and 953 are novel second-generation recombinant forms of HIV-1 CRF01_AE and subtype B. The NFLG phylogenetic tree analysis showed that these two NFLG sequences formed a unique monophyletic branch, respectively. The recombination breakpoints analysis showed that the recombination pattern of both sequences was that a subtype B fragment was inserted into a CRF01_AE backbone. Subregions I, II, and III were from CRF01_AE, subtype B, and CRF01_AE, respectively. The recombination breakpoints relative to HXB2 of sequences 233 and 953 were 2400 and 4870, and 3363 and 4828, respectively. The emergence of novel recombinant forms of CRF01_AE/B demonstrates that we should carry out the ongoing surveillance of HIV-1 recombinant forms in the sexually transmitted population.

Prevalence of resistance mutations associated with integrase inhibitors in therapy-naive HIV-positive patients in Baoding, Hebei province, China.

Antiretroviral therapy (ART) regimens containing integrase strand transfer inhibitors (INSTIs) are the recommended treatment for human immunodeficiency virus type 1 (HIV-1)-infected patients in the most recent guidelines in China. In this study, we investigated INSTI resistance mutations in newly diagnosed therapy-naive HIV-positive patients in Baoding City, Hebei Province (China) to provide guidance for implementing routine INSTI-associated HIV-1 genotypic resistance testing. Plasma samples were collected from HIV-1-infected patients without treatment at Baoding People's Hospital from January 2020 to December 2021. The part of HIV-1 pol gene encoding integrase was amplified, sequenced, and analyzed for INSTI resistance. Clinical data including demographic data, CD4+ T cell counts, HIV-RNA loads, and resistance mutations were collected. Treatment-naïve HIV-1 patients (n = 131) were enrolled. We identified ten genotypes, and the predominant genotype was CRF01_AE in 67 patients (51.15%), CRF07_ BC in 39 patients (29.77%), subtype B in 11 patients (8.40%), and other subtypes (CRF68_01B, 3.82%; CRF55_01B, 1.53%, CRF80_0107, 1.53%; URFs 1.53%; and CRF103_01B, CRF59_01B, and CRF65_cpx, 1.4% each). Four major (E138A, R263k, G140S, and S147G) and three accessory (H51Y, Q146QL, and S153F) INSTI-resistance mutations were observed (genotype CRF01_AE, three patients; genotype B, one patient; and genotype CRF07_BC, one patient), resulting in different degrees of resistance to the following five INSTIs: raltegravir, elvitegravir, dolutegravir, bictegravir, and cabotegravir. The overall resistance rate was 3.82% (5/131). All INSTI-resistant strains were cross-resistant. The primary INSTI drug resistance rate among newly diagnosed HIV-infected patients in Baoding was low, but monitoring and research on HIV INSTI resistance should be strengthened in Baoding because INSTI-based regimen prescriptions are anticipated to increase in the near future.

Genetic characterization of a novel HIV­1 CRF01_AE/ CRF07_BC recombinant form found among men who have sex with men in Baoding City, Hebei Province, China.

Large numbers of unique recombinant forms (URF) of human immunodeficiency virus (HIV-1) have been found among sexual transmission populations in China. Here, we report a novel second-generation URF of HIV-1 named BD201AQ that was isolated from an HIV-1-positive man who was infected through homosexual transmission in Baoding City, Hebei Province, China. Phylogenetic analysis based on the near-full-length genome (NFLG) sequence indicated that BD201AQ formed a monophyletic branch that did not cluster with other HIV-1 subtypes. Recombination analysis showed that the NFLG of BD201AQ had 12 segments, six CRF07_BC and six CRF01_AE segments, with CRF07_BC as the main framework. These findings indicate that the constant emergence of novel recombinant forms should receive more attention and that more measures should be taken to monitor the molecular epidemiological characteristics of HIV-1 and to prevent the spread of HIV-1 infections.

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.

Identification of a New HIV-1 CRF68_01B/CRF01_AE Recombinant Form Among Men Who Have Sex with Men in Hebei Province, China.

In recent years, homosexual contact has been the most frequent route of human immunodeficiency virus type one (HIV-1) transmission in Hebei, China. The number of circulating recombinant forms (CRFs) and unique recombinant forms found in this key population were more and more. In this study, we identified a novel HIV-1 second-generation recombinant form originated from CRF68_01B and CRF01_AE among men who have sex with men (MSM) through the phylogenetic and recombinant breakpoints analyses based on the near full-length genome. Both CRF68_01B and CRF01_AE were circulating in the Hebei province of China, and this MSM was diagnosed as the recent HIV-1 infection in fact. The result reminds that we should constantly monitor HIV-1 diversity in Hebei and take further effective to control the recombination of not only HIV-1 major strains but also minor strains.

Efficacy, Safety, and Prognosis of Sequential Therapy with Tamoxifen and Letrozole versus Letrozole Monotherapy for Breast Carcinoma.

Objective: To explore the efficacy, safety, and patient prognosis of letrozole (LTZ) alone or in sequence with tamoxifen (TAM) for the treatment of breast carcinoma (BC). Methods: In this retrospective study, 150 patients with BC who received treatment in the First People's Hospital of Ningyang County between January 2012 and January 2017 were selected. According to different treatment methods, 99 cases receiving sequential therapy with TAM and LTZ were included in the research group, and the remaining 51 patients receiving LTZ monotherapy were selected as the control group. The efficacy, safety, survival rate, recurrence rate, and blood lipid indices (total cholesterol, TC; triglyceride, TG; high-density lipoprotein cholesterol, HDL-C; and low-density lipoprotein cholesterol, LDL-C) of the two groups were observed and compared. Results: The overall response rate of the research group was statistically higher than that of the control group, and the incidence of adverse reactions was significantly lower. No evident difference was observed in 1-, 3-, or 5-year survival rates between the two groups, while the 3-5-year recurrence rate was obviously lower, and the improvement of blood lipid indices was significantly better in the research group compared with the control group. Conclusion: LTZ alone or in sequence with TAM is effective and safe for the treatment of BC, which can significantly improve the prognosis and blood lipid indices of BC patients.

CRF07_BC is associated with slow HIV disease progression in Chinese patients.

HIV subtypes convey important epidemiological information and possibly influence the rate of disease progression. In this study, HIV disease progression in patients infected with CRF01_AE, CRF07_BC, and subtype B was compared in the largest HIV molecular epidemiology study ever done in China. A national data set of HIV pol sequences was assembled by pooling sequences from public databases and the Beijing HIV laboratory network. Logistic regression was used to assess factors associated with the risk of AIDS at diagnosis ([AIDSAD], defined as a CD4 count < 200 cells/µL) in patients with HIV subtype B, CRF01_AE, and CRF07_BC. Of the 20,663 sequences, 9,156 (44.3%) were CRF01_AE. CRF07_BC was responsible for 28.3% of infections, followed by B (13.9%). In multivariable analysis, the risk of AIDSAD differed significantly according to HIV subtype (OR for CRF07_BC vs. B: 0.46, 95% CI 0.39─0.53), age (OR for ≥ 65 years vs. < 18 years: 4.3 95% CI 1.81─11.8), and transmission risk groups (OR for men who have sex with men vs. heterosexuals: 0.67 95% CI 0.6─0.75). These findings suggest that HIV diversity in China is constantly evolving and gaining in complexity. CRF07_BC is less pathogenic than subtype B, while CRF01_AE is as pathogenic as B.

Characterization of a New HIV-1 CRF01_AE/B Recombinant Virus Form Among Men Who Have Sex with Men in Baoding, Hebei, China.

We analyzed the near full-length genome (NFLG) of an HIV-1-positive sample(027A) with an undetermined subtype to determine the recombinant characteristics and possible source of the parental virus. 027A is a novel HIV-1 second-generation recombinant form composed of CRF01_AE and subtype B, detected from a married HIV-1-positive male subject who was infected through homosexual transmission in Baoding, Hebei province, China. The NFLG phylogenetic tree analysis suggested that the strain was close to circulation recombinant forms' (CRFs') reference sequences involved with CRF01_AE, but formed a distinct monophyletic cluster separately from them. This indicated that the strain might be a unique CRF01_AE-related recombinant from. Furthermore, the results of RIP and jpHMM further demonstrated that the NFLG sequence of the strain was composed of CRF01_AE and subtype B. The strain was two CRF01_AE fragments inserted into B backbone. Phylogenetic analysis illustrated that the CRF01_AE subregions were from the previously identified CRF01_AE cluster 4, and the B subregions were correlated with the B strains originated from Europe and America. They were all the lineages widely prevalent in men who have sex with men (MSM) population in China. In recent years, a large number of recombinant originated from CRF01_AE and B strains are constantly emerging in MSM population in China. This continual and recurrent recombination between CRF01_AE and B in high-risk group people deserves more attention and further monitoring.

Molecular transmission networks and pre-treatment drug resistance among individuals with acute HIV-1 infection in Baoding, China.

BACKGROUND: Human immunodeficiency virus type 1 (HIV-1) genetic diversity and pre-treatment drug resistance (PDR) are major barriers to successful antiretroviral therapy (ART). In China, sexual intercourse is the most frequent route of HIV-1 transmission. However, few studies have analyzed PDR and transmission networks in detail among individuals in China with acute HIV-1 infection and their sexual contacts. METHODS: A cross-sectional study was conducted in Baoding City, Hebei Province, China from 2019-2020. CD4 T cell counts and viral loads were assessed and a HIV-1 genotypic PDR assay was developed in-house. Transmission networks were visualized using Cytoscape with a threshold genetic distance of 0.015 among HIV-1 subtypes. RESULTS: From 139 newly diagnosed and drug-naïve individuals with HIV-1, 132 pol gene sequences were obtained and revealed eight HIV-1 subtypes. Circulating recombinant form (CRF)01_AE was the most frequent subtype (53.0%, 70/132) followed by CRF07_BC (26.5%, 35/132), B (13.6%, 18/132), unique recombinant forms (2.3%, 3/132), CRF55_01B (1.5%, 2/132), CRF103_01B (1.5%, 2/132), CRF65_cpx (0.8%, 1/132), and C (0.8%, 1/132). A total of 47 pol gene sequences were used to generate 10 molecular transmission networks. The overall prevalence of PDR was 7.6% and that of PDR to non-nucleotide reverse transcriptase inhibitors was 6.1%. Of three transmission networks for PDR, two were closely associated with Beijing and Tianjin, while another was restricted to sequences determined in this study. CONCLUSIONS: These results demonstrate that during acute HIV-1 infection, PDR is transmitted in dynamic networks. This suggests that early detection, diagnosis, surveillance, and treatment are critical to effectively control HIV-1 spread.

Genome Sequence of a Novel HIV-1 Circulating Recombinant Form (CRF103_01B) Identified from Hebei Province, China.

We reported a novel HIV-1 circulating recombinant form (CRF) among three epidemiologically unlinked patients through men having sex with men in Hebei Province, China. It was named CRF103_01B (this is temporary as we have not received the CRF number from HIV databases). A near full-length genome phylogenetic tree showed that CRF103_01B was generated by three B (Western origin) segments and CRF01_AE that was described as cluster 5 lineage of CRF01_AE (CRF01-5). The emergence of CRF103_01B increased the complexity of the HIV-1 epidemic in China.

Large Transmission Clusters of HIV-1 Main Genotypes Among HIV-1 Individuals Before Antiretroviral Therapy in the Hebei Province, China.

In recent 10 years, the sexual contact transmission has led to the consecutive upsurge of HIV in Hebei. Especially, the risk behaviors such as homosexual contact in Hebei have presented challenges for HIV prevention and treatment efforts. In this study, we found that 98.9% of subjects attributed their HIV-1 infections to sexual contact, and men who have sex with men (MSM) accounted for 77.5%. CRF01_AE (49.6%), CRF07_BC (29.7%), and subtype B (13.0%) were three main genotypes. AE_cluster 1 (73 cases), AE_cluster 2 (62 cases), and 1 large 07_BC cluster (75 cases) were identified, and only closely clustered with MSM sequences from Beijing. Further, all of HIV-1-resistant strains were circulating in transmission clusters. Particularly, 76.5% of subjects resistant to drugs were circulating in above three large transmission clusters associated with MSM from Beijing. Our study proved that the busy movement of MSM between Beijing and Hebei could meet conveniently, which might result in the bidirectional exchange of HIV-1 strains between Beijing and Hebei. As the most frequent genotypes, large transmission clusters associated with CRF01_AE and CRF07_BC have become one of the main factors resulting in the rapid increase of HIV in Hebei. Therefore, the enhanced surveillance for HIV should be planned early among the floating population traveling between Beijing and Hebei. Hebei should construct the cooperative mechanism for HIV prevention and control together with Beijing.