The infection rates of HBV and HCV decreased significantly in Zhejiang Province, China: A comparative study based on the data of two sero-epidemiological surveys in 1992 and 2020.

In 2020, China conducted a nationwide, sero-epidemiological, cross-sectional survey of viral hepatitis. The stratified multi-stage cluster random sampling method was used to select the permanent population aged 1-69 years, followed by questionnaire survey and sample collection and detection of the serological markers of hepatitis B (HBV) and hepatitis C viruses (HCV). A total of 4747 individuals aged 1-69 years were investigated in Zhejiang Province. The positive rates of hepatitis B surface antigen and anti-HCV were 4.3% and 0%, respectively. Compared to a similar sero-epidemiological survey in 1992, the 2020 survey showed that the HBV infection rate in Zhejiang Province decreased by 56.5%. In both surveys, HBV infection rate increased with age (in 1992, χ2  = 185.866, p = .000; in 2020, χ2  = 1383.836, p = .000). Compared with 1992, the positive anti-HCV rate in those aged 1-69 years in 2020 decreased by 100.0%. This result showed that the HBV vaccine and blood screening to prevent HBV and HCV infection significantly decreased the infection rate of HBV and HCV in the younger generation of Zhejiang province. However, the rate of HBV carriers aged 30-69 years was still high, which underscores the need to strengthen the management and treatment of chronic HBV infection. Hence, Zhejiang province can eliminate the public health threat of viral hepatitis.

Combining molecular network analysis and field epidemiology to quantify local HIV transmission and highlight ongoing epidemics.

OBJECTIVES: This study aimed to establish a collaborative approach to quantify local HIV transmission, which is an issue of great concern to public health. METHODS: We linked HIV-1 pol gene sequences to demographic information and epidemiological investigations in Hangzhou (a central city in East China). We estimated local acquisition rates from a collaboration of molecular network analysis (with a distance-based approach) and epidemiological investigations. RESULTS: Among 1064 newly diagnosed patients with HIV, 857 pol sequences were acquired and subsequently analyzed. Multiple subtypes were identified, with circulating recombinant form (CRF)07_BC (42.5%) and CRF01_AE (39.2%) predominating, followed by 13 other subtypes and 26 unique recombinant forms. By integrating the molecular network analysis and epidemiological investigations, we estimated that the proportion of local infection was 63.2%. The multivariable analyses revealed that individuals in clusters were more likely to be local residents, be aged 50 years or older, work as farmers, and have a higher first cluster of differentiation 4 count level (P <0.05). The proportions of local acquisitions over 70% were observed in local residents (79.9%, 242/303), individuals aged 50 years or older (73.6%, 181/246), and farmers (75.6%, 99/131). CONCLUSION: The molecular network analysis can augment traditional HIV epidemic surveillance. This study establishes a paradigm for quantifying local HIV transmission for generalization in other areas.

Identification and genomic characterization of a novel HIV-1 unique recombinant form (CRF01_AE/CRF07_BC) in Zhejiang Province, China.

Mutation and recombination are important mechanisms leading to the frequent evolution and genetic diversity of viruses as HIV-1. In this study, we identified the near full-length genomic characterization of a novel HIV-1 unique recombinant form (URF) strain (Sample ID: ZJ20202195/ZJ/CHN/2020, hereafter referred to as ZJ20202195) isolated during the HIV-1 molecular surveillance in 2020 in Zhejiang Province, China, through different recombination analysis tools and phylogenetic analysis. Our results amply proved that the near full-length genome (NFLG) sequence of ZJ20202195 was a novel HIV-1 unique recombinant form (URF) consisting of CRF01_AE and CRF07_BC subtype, and delimited three recombinant segments, of which the Segment I (HXB2:776-5559 nucleotide (nt)) and Segment III (HXB2:6224-9412 nt) were mainly originated from CRF01_AE cluster g4a strains prevalent in China and Segment II (HXB2:5560-6223 nt) was from CRF07_BC subtype. Overall, our findings provide insight and a scientific basis in the genetic diversity and accurate determination of HIV-1 recombinant strains in China.

Molecular genetics and epidemiological characteristics of HIV-1 epidemic strains in various sexual risk behaviour groups in developed Eastern China, 2017-2020.

In this study, we conducted a detailed molecular epidemiological analysis of HIV-1 epidemic strains in various sexual risk behaviour groups in a developed area in eastern China based on phylogenetic inference, molecular transmission networks, and Bayesian analyses. A total of 1083 pol sequences (91.23%, 1083/1187) from newly diagnosed HIV-1-positive patients from 2017 to 2020 were successfully obtained and involved thirteen HIV-1 subtypes, in which the major HIV-1 subtypes were CRF07_BC (36.10%, 391/1083) and CRF01_AE (34.63%, 375/1083). 485 individuals (44.78%,485/1083) formed 146 clusters in the network. Of which CRF07_BC showed extensive clustering driven by men who have sex with men (MSM) within larger networks, CRF01_AE and other subtypes were generally driven by small clusters (SCs) and medium clusters (MCs) among various risk groups. Through Sankey diagrams, the MSM group infected with CRF07_BC had a greater impact on the non-commercial heterosexual group among all cross-risk groups. In addition, a higher number of key individuals infected with CRF07_BC (40.22%, 74/127), suggests the crucial role of CRF07_BC-infected individuals as a local epidemic driver in the context of a mixed HIV-1 epidemic. Further Bayesian analysis confirmed that CRF07_BC was introduced into Jiaxing city from other provinces multiple times and spread rapidly among MSM and heterosexual individuals. Overall, our study provided some insights and information to explore the local transmission dynamics of HIV-1 epidemic strains involving various sexual risk groups, and emphasize that it is necessary to conduct in-depth research and precise intervention targeting key clusters/ individuals to effectively block the continued transmission of AIDS.

Characterizing genetic transmission networks among newly diagnosed HIV-1 infected individuals in eastern China: 2012-2016.

We aimed to elucidate the characteristics of HIV molecular epidemiology and identify transmission hubs in eastern China using genetic transmission network and lineage analyses. HIV-TRACE was used to infer putative relationships. Across the range of epidemiologically-plausible genetic distance (GD) thresholds (0.1-2.0%), a sensitivity analysis was performed to determine the optimal threshold, generating the maximum number of transmission clusters and providing reliable resolution without merging different small clusters into a single large cluster. Characteristics of genetically linked individuals were analyzed using logistic regression. Assortativity (shared characteristics) analysis was performed to infer shared attributes between putative partners. 1,993 persons living with HIV-1 were enrolled. The determined GD thresholds within subtypes CRF07_BC, CRF01_AE, and B were 0.5%, 1.2%, and 1.7%, respectively, and 826 of 1,993 (41.4%) sequences were linked with at least one other sequence, forming 188 transmission clusters of 2-80 sequences. Clustering rates for the main subtypes CRF01_AE, CRF07_BC, and B were 50.9% (523/1027), 34.2% (256/749), and 32.1% (25/78), respectively. Median cluster sizes of these subtypes were 2 (2-52, n = 523), 2 (2-80, n = 256), and 3 (2-6, n = 25), respectively. Subtypes in individuals diagnosed and residing in Hangzhou city (OR = 1.423, 95% CI: 1.168-1.734) and men who have sex with men (MSM) were more likely to cluster. Assortativity analysis revealed individuals were more likely to be genetically linked to individuals from the same age group (AIage = 0.090, P<0.001) and the same area of residency in Zhejiang (AIcity = 0.078, P<0.001). Additionally, students living with HIV were more likely to be linked with students than show a random distribution (AI student = 0.740, P<0.01). These results highlight the importance of Hangzhou City in the regional epidemic and show that MSM comprise the population rapidly transmitting HIV in Zhejiang Province. We also provide a molecular epidemiology framework for improving our understanding of HIV transmission dynamics in eastern China.

Performance of HIV detection in Zhejiang province in China: The Pareto principle at work.

BACKGROUND: Timely detection of HIV infection is critical for curbing the AIDS epidemic, and building an extensive and effective HIV laboratory network is of great importance. Therefore, improving quality management of the laboratory network and optimizing detection strategies are desirable research issues. METHODS: We assessed the applicability of the Pareto principle to HIV detection performance. We conducted a retrospective review of basic information and numbers of screening tests among an HIV laboratory network (1,452 laboratories) in Zhejiang province in 2014 and statistically analyzed HIV testing data for different population categories. RESULTS: Approximately, 80% of the cumulative HIV screening tests and positive screening tests originated from 17.3% (251/1,452) and 11.7% (170/1,452) of the laboratories in the whole province, respectively, and similar patterns were observed at the prefectural level. We found that the top five population screening categories (25%, 5/20) had the highest contribution (approximately 80%) to not only the number of screening tests (77.2%) but also the numbers of positive (76.4%) and confirmed positive tests (81.5%). CONCLUSIONS: The Pareto principle provides a method for identifying noteworthy laboratories to deliver prior quality supervision and developing highly efficient screening strategies that best suit local needs.

Analysis of the Driving Factors of Active and Rapid Growth Clusters Among CRF07_BC-Infected Patients in a Developed Area in Eastern China.

BACKGROUND: The purpose of this study was to research the molecular transmission and genetic evolutionary characteristics among CRF07_BC-infected patients in a developed area in Eastern China. METHODS: Plasma samples from newly diagnosed HIV-1-positive patients from 2015-2018 and basic demographic and epidemiological information were obtained. Pol sequences from CRF07_BC-infected patients were selected for phylogenetic, molecular transmission network, and Bayesian evolutionary analyses. RESULTS: Pol sequences were successfully obtained from 258 samples of CRF07_BC. Phylogenetic analysis revealed 2 distinct lineages: lineage 1 (66.3%, 171/258), primarily from men who have sex with men (MSM) and some heterosexual individuals, and lineage 2 (33.7%, 87/258), primarily from heterosexual individuals. Under an optimal genetic distance of 0.01 substitutions/site, 163 individuals (63.2%, 163/258) formed 23 groups comprising 6 clusters and 17 dyads in the networks. A distinctly large and rapidly growing cluster (C1) containing 105 individuals was identified, in which MSM with ≥4 links had quite a high transmission risk (low educational background, active sexual behavior, low sexual protection awareness, etc.). According to Bayesian analyses, most C1 clades formed from 2005 to 2009, most of which were closely geographically related to CRF07_BC epidemic strains from Anhui province. CONCLUSIONS: Here, we elucidated the local transmission characteristics and epidemic pattern of HIV-1 CRF07_BC, revealing that MSM (especially with ≥4 links) may be a significant driver in the formation of active and rapid growth networks in regional CRF07_BC epidemics. Thus, unique region- and risk group-specific transmission network analysis based on a molecular approach can provide critical and insightful information for more effective intervention strategies to limit future HIV-1 transmission.

A Geographic Hotspot and Emerging Transmission Cluster of the HIV-1 Epidemic Among Older Adults in a Rural Area of Eastern China.

Despite the implementation of health education and free condom distribution for decades, the HIV/AIDS epidemic among older adults in China shows no sign of declining. This study aims to identify HIV transmission patterns and pathways in a rural county area and provide insight for developing effective HIV prevention strategies among older adults. Epidemiological field surveys combined with phylogenetic analysis were used to identify potential HIV transmission linkage in one rural county with a rapidly increasing HIV epidemic among older adults. A total of 160 HIV-positive individuals and their HIV-positive sexual partners diagnosed between 2015 and 2018 were recruited. Among them, 69.4% (n = 111) were diagnosed at age 50 or older, 68.1% (n = 109) were men, and 55.0% (n = 88) were married. Ninety-six participants self-reported as having been infected with HIV through commercial heterosexual behavior and 24 were infected from their HIV-positive spouse. CRF08_BC (67.0%, n = 73) and CRF07_AE (19.3%, n = 21) were the prevalent HIV stains and formed 15 clusters at distance cutoff of 0.0025. Participants diagnosed with HIV at age ≥50, those who were divorced or bereft their spouse, or infected with HIV locally were more prevalent within the 15 molecular clusters. We identified specific venues as the primary hotspot and found that commercial heterosexual contact between older men and commercial sex workers contributed to the local HIV epidemic. In rural areas with an increasing HIV epidemic, detecting HIV transmission clusters through epidemiological and phylogenetic analysis as well as designing localized HIV prevention strategies should be prioritized.

Migration interacts with the local transmission of HIV in developed trade areas: A molecular transmission network analysis in China.

The HIV-1 epidemic is a remarkable public health concern in China, especially in developed trade areas. We aimed to investigate the interaction of migration with the local transmission network in a typical trade area, Yiwu City, the world's largest commodity distribution center. Based on 390 pol sequences from 413 participants diagnosed between 2014 and 2016, putative transmission clusters and the underlying demographic and behavioral characteristics were analyzed. Recent infection status was determined by HIV-1 limiting antigen avidity enzyme immunoassay to identify active clusters. Multiple subtypes were identified, with a predominance of CRF01_AE (47.4%) and CRF07_BC (40.8%), followed by 9 other subtypes and 8 URFs. Multivariable analyses revealed that individuals in clusters were more likely to be local residents, infected through heterosexual behaviors, and infected with CRF01_AE (P < .05). Of men who have sex with men (MSM), 81% were linked to other MSM, and only 3% were linked to heterosexual women. Of heterosexual women, 67% were linked to heterosexual men, and 11% to MSM. Yiwu residents were more likely to link to locals than that of migrants (43% vs 20%, P < .001). By contrast, local MSM and migrant MSM all had high percentages of linkage to migrant MSM (57% vs 69%, P = .069). Our findings reveal that migration promotes the dissemination and dynamic change of HIV, which are interwoven between locals and migrants. The results highlight the far-reaching influence of migrant MSM on the local HIV transmission network.

Short Communication: Discordance of HIV-1 Viral Load from Paired Blood and Seminal Plasma Samples in a Chinese Men Who Have Sex with Men Population.

The alarming spread of HIV among men who have sex with men (MSM) has become a national concern in China. Estimating men's sexual HIV infectiousness from blood plasma viral load (BPVL) depends on the association between BPVL and seminal plasma viral load (SPVL). However, previous studies were controversial and few concentrated on MSM. Twenty antiretroviral therapy (ART)-naive MSM and 54 MSM under ART were recruited between July and September 2015 in the city of Hangzhou, China. Blood and semen were collected in pairs at the same visit for each individual. BPVL and SPVL were measured by COBAS AmpliPrep/COBAS TaqMan HIV-1 Test ver2.0. The mean viral load in blood plasma was higher than that in semen (4.5 ± 0.9 log10 vs. 3.4 ± 1.3 log10) in 20 ART-untreated MSM, and a positive correlation was found between BPVL and SPVL, as evaluated by linear regression (R2 = 0.565, p < .001). A total of 96.3% (52/54) of ART-treated patients had successful viral suppression (<400 copies/mL) according to the BPVL. Fourteen subjects (25.9%, 14/54) presenting undetectable SPVL showed detectable BPVL, ranging from 20.4 to 7,470 copies/mL. Three subjects (5.6%, 3/54) presented detectable SPVL although BPVL was undetectable. MSM could pose a transmission risk despite undetectable BPVL. Consistent use of condoms and other risk-reduction strategies should be strongly advocated in MSM throughout all stages of HIV infection, regardless of ART.

Outbreak of HIV Infection Linked to Nosocomial Transmission, China, 2016-2017.

On January 25, 2017, a physician from ZC Hospital in Hangzhou, China, reported to the Zhejiang Provincial Center for Disease Control and Prevention that a potential HIV outbreak might have occurred during lymphocyte immunotherapy (LIT) performed at the hospital on December 30, 2016. We immediately began investigating and identified the index case-patient as an LIT patient's husband who donated lymphocytes for his wife's LIT and later screened HIV-reactive. Subsequent contamination by a technician resulted in the potential exposure of 34 LIT patients. Acute HIV infection was diagnosed in 5 persons. Phylogenetic analysis confirmed that the HIV-1 gag, pol, and env gene sequences from the index and outbreak-related cases had >99.5% similarity. Rapid investigation and implementation of effective control measures successfully controlled the outbreak. This incident provides evidence of a lapse in infection control causing HIV transmission, highlighting the need for stronger measures to protect patients from infectious disease exposure.

Highlighting the crucial role of Hangzhou in HIV-1 transmission among men who have sex with men in Zhejiang, China.

In recent years, the population of men who have sex with men (MSM) constitute a major group for HIV transmission in China. A total of 340 newly reported HIV-infected MSM were recruited proportionally from ten prefectures across Zhejiang province between January and December in 2013. Partial pol gene was amplified and sequenced. Phylogenetic relationship, transmission network and genotypic drug resistance analyses were performed on 311 sequences. HIV-1 subtypes including CRF01_AE (55.9%), CRF07_BC (37.6%), subtype B (1.9%), CRF55_01B (1.3%), CRF68_01B (0.3%), CRF08_BC (0.3%) and URFs (2.6%) were identified. A higher proportion of CRF07_BC and other subtypes existed in the >35 years group, while a higher proportion of CRF01_AE was present in the young group (<35 years). Low prevalence of transmitted drug resistance was found (3.9%, 12/311). Strains with Hangzhou imprints were diffused across the full phylogenetic tree. Moreover, Hangzhou represented the dominant proportion of local HIV transmission (72.0%) and cross-regional transmission (62.4%) based on the provincial transmission network and possessed the largest number of nodes with ≥50 edges, accounting for 50.0% (10/20). The complexity of HIV subtypes and an intertwined network was noticed in MSM in Zhejiang province. Hangzhou likely plays a central regional role in the intra-provincial spread of HIV.

Trends of HIV-1 Subtypes Among Young People in Hangzhou, China.

To investigate the HIV-1 molecular epidemiology among young people (18 to 25 years old) in Hangzhou. Plasma samples from 262 newly diagnosed HIV-1-infected patients were collected between 2009 and 2013 from Hangzhou of Zhejiang province. HIV-1 nucleotide sequences of pol gene regions were amplified using a nested polymerase chain reaction method and sequenced. Phylogenetic and recombination analyses were used to determine the HIV-1 genotypes. Based on all sequences generated, the subtype/circulating recombinant forms (CRFs) distribution was as follows: CRF01_AE (68.70%), CRF07_BC (21.54%), subtype B (3.66%), CRF08_BC (2.44%), 01B (2.03%), BC (0.81%), and C (0.41%). We found that the percentage of CRF07_BC was increasing year by year among young people in Hangzhou. Novel CRFs such as CRF67_01B (HZ2011-15 CD4-4516) and CRF68_01B (HZ2011-20 CD4-4530 and HZ2011-29 CD4-4087) were first discovered in the area in this study. Our study presents a molecular epidemiology investigation describing the structure of HIV-1 strains cocirculating in young people in Hangzhou. Increasing CRF07_BC and new CRFs popular in young people are a challenge for future prevention in Hangzhou.

[HIV-1 subtype diversity and transmission clusters among men having sex with men who recently got HIV-l infection, in Zhejiang province].

OBJECTIVE: To understand the HIV-1 subtype diversity and transmission characteristics in men having sex with men (MSM) in Zhejiang province. METHODS: A total of 233 newly diagnosed as HIV-1 positive patients in 2011 were screened out by BED capture enzyme immunoassay (BED-CEIA). Among them, 107 eligible subjects were enrolled for further molecular epidemiological study. Viral RNA was extracted from plasma samples and followed by reverse transcription PCR and nested PCR for amplification of pol gene fragments, sequencing, and bioinformatics analysis. RESULTS: There were no statistically significant differences regarding the social demographic distribution between the subjects under study and those recently infected MSM population. The rate of success for sequence acquisition was 94.4% (101/107). The highest proportion of subtype was CRF01_AE (62.4%), followed by CRF07_BC (31.7%) and with three cases of subtype B, one case of CRF55_01B and two cases of unique recombinant form (CRF01_AE/B and CRF01_AE/CRF07_BC). The phylogenetic trees were mainly divided into CRF01_AE cluster 1, cluster 2 and CRF07_BC cluster 3. The strains located in Hangzhou were diffused in the branches of phylogenetic tree. 10 transmission clusters were found, in which 80% involved two or more regions and 90% was associated with patients residing in Hangzhou. Three surveillance drug resistance mutations (M46I, T215S and G190A) were found in three samples (each sample harbored only one resistance mutation). The overall rate of transmitted drug resistance (TDR) was 2.97%. CONCLUSION: The increasing complexity of HIV was noticed in MSM in Zhejiang province. However, the prevalence of TDR was low. Cross-regional HIV transmission in MSM was common, which inferred from the study. Hangzhou might play a central regional role in the intra-provincial spread of HIV, to form an interwoven complex network in the MSM population.

Genetic diversity of HIV-1 and transmitted drug resistance among newly diagnosed individuals with HIV infection in Hangzhou, China.

HIV transmitted drug resistance (TDR) can compromise antiretroviral therapy (ART) in resource-limited countries like China where ART has been scaled up and thus leads to an important public health concern. The aim of the study was to elucidate the HIV-1 genetic characteristics and TDR in Hangzhou, China. Two-hundred eleven ART-naive, newly diagnosed individuals were enrolled during January and August 2013. Specimens were classified as recent or chronic infections using the BED capture enzyme immunoassay (BED-CEIA). The pol fragment covering the entire protease and the first 300 codons of the reverse transcriptase gene was amplified by RT-PCR and nested PCR. Genotypic drug resistance (DR) and phylogenetic analysis were performed on the 200 obtained sequences. Multiple genotypes were identified, including CRF01_AE (62.0%), CRF07_BC (31.0%), subtype B (2.0%), CRF08_BC (1.5%), CRF55_01B (1.0%), CRF18_cpx (0.5%), and unique recombinant forms (URFs, 2.0%). All the four URFs were found in men who have sex with men, consisting of a recombination of CRF01_AE with subtype B or CRF07_BC. The prevalence of primary DR in newly diagnosed individuals in Hangzhou was low (4.0%). The proportion of DR mutation to protease inhibitors (PIs), nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs) was 1.5%, 1.5%, and 1.0%, respectively. BED-CEIA revealed that 21.8% (45/211) of the specimens were associated with recent infections. The prevalence of TDR in recent infections was moderate (6.5%). High HIV diversity and relatively high prevalence of TDR in new infections has been found in Hangzhou, indicating an increasing challenge for future HIV prevention and treatment.

[Molecular epidemiological study on HIV/AIDS under the follow-up program in Zhejiang province in 2009].

OBJECTIVE: To analyze the molecular epidemiological characteristics on HIV infectors/AIDS patients (HIV/AIDS) under a follow-up program in Zhejiang province in 2009. METHODS: 303 cases were randomly sampled. Information on the cases was collected and followed by genomic DNA extraction. Gag gene fragments were amplified by nested PCR, followed by sequencing and bio-informatic analysis. RESULTS: The rate of success for sequence acquisition was 74.3% (225/303). Distributions of HIV subtypes were as follows: CRF01_AE (58.7%), CRF07_BC (13.8%), CRF08_BC (9.8%), B' (15.1%), C (1.8%), G (0.4%) and unassigned BC (unique recombinant form 0.4%). RESULTS: from the HIV BLAST analysis showed that the sources of strains with the highest homology involved in 10 provinces/municipalities (Liaoning, Guangxi, Yunnan, Henan, etc.) and five other countries (Thailand, Vietnam, India, South Africa and Libya). The CRF01_AE phylogenetic tree was divided into four clusters. The sequences of HIV/AIDS with homosexual transmission showed a gather in cluster 1, and mix with those infected through heterosexual contact. CONCLUSION: Circulating recombinant forms of HIV seemed to play a dominant role in Zhejiang province. Unique recombinant form and new subtype of HIV were found. People living with HIV under homosexual transmission and heterosexual transmission had a trend of interwoven with each other. Increase of both the diversity and complexity of HIV strains were also noticed in Zhejiang province.

[Molecular characteristics of HIV-1 CRF01_AE strains in Zhejiang province in 2009].

OBJECTIVE: To analyze the molecular epidemiological characteristics of HIV-1 subtype CRF01_AE strains being prevailed among HIV/AIDS in Zhejiang province in 2009. METHODS: A total of 303 subjects were identified by stratified random sampling among HIV infected individuals in Zhejiang province in 2009. Gag fragments of the HIV-1 strains were amplified by nested polymerase chain reaction from the DNA extracted from whole blood of HIV-1 infected individuals. PCR products were sequenced and analyzed by phylogenetic method. RESULTS: A total of 132 HIV-1 subtype CRF01_AE sequences were identified from the 225 samples that sequenced successfully, accounting for 58.67% (132/225). A total of 90.91% (120/132) CRF01_AE strains infected HIV/AIDS were transmitted mainly by sexual contacts. A total of 65.91% (87/132) of the cases infected by heterosexual route and 25.00% (33/132) by homosexual route. There were three main clusters in the phylogenetic tree. Pairwise DNA distance within three groups was 0.037 ± 0.011, 0.034 ± 0.008 and 0.047 ± 0.010, which has statistical significance (P < 0.05). Distribution of the sequence of homosexual behavior infected individuals was relatively concentrated in clusters one (96.97%, 32/33), and crossed with heterosexual behavior infectors, and presented the close relations with strains from Jiangsu province, Zhengzhou of Henan province, Liaoning province, Shijiazhuang of Hebei province. CONCLUSION: The CRF01_AE strains were the dominant subtypes among HIV infected individuals. The majority of the CRF01_AE infected cases had high risk sexual behavior. The heterosexual infected cases were more than homosexual cases. The circulating status of CRF01_AE strains in homosexual population was relatively independent, but also had evidence of transmission from man who have sex with man to heterosexual population.

[Preliminary study on bacteroides as the potential fecal contamination indicator bacteria].

OBJECTIVE: To explore the possibility of Bacteroides spp. as fecal contamination indicator bacteria with real-time quantitative PCR (RT-PCR) assay through analyzing the correlation between Bacteroides spp. and coliform group in external environment. METHODS: Quantity of coliform group and Bacteroides in water samples were detected by most-probable-number method (MPN) and RT-PCR, respectively, and their detection correlation was evaluated with linear correlation analysis. Both methods were also applied to detect the contaminated time limits and river water samples collected at four sampling sites in three different times. RESULTS: Seventy two hours were needed for the numeration of coliform group with MPN method, while RT-PCR could detect Bacteroides within 3 hours. The contaminated time limit of indoor and outdoor water samples of coliform group was more than 40 days and 9 days, and Bacteroides 13 days and 5 days, respectively. Also, the positive correlation between the quantity of Bacteroides and coliform group in outdoor water samples was obtained, the quantity of Bacteroides was from 8.3 × 10(6) copies/ml to less than 10(4) copies/ml during the first day to the fifth day, while coliform group was 4.3 × 10(6) MPN/100 ml to 2.4 × 10(3) MPN/100 ml. A 100% coincidence rate of the detection results with both methods was also observed. These results indicated that the detection results of both methods had perfect consistency. CONCLUSION: Bacteroides spp. can be potentially used as fecal contamination indicator bacteria with RT-PCR rapid detection.

Gut bacteria alteration in obese people and its relationship with gene polymorphism.

AIM: To investigate the differences in cultivable gut bacteria and peroxisome proliferator-activated receptor γ2 (PPAR-γ2) gene Pro12Ala variation in obese and normal-weight Chinese people. METHODS: Using culture methods, the amounts of Escherichia coli, Enterococci, Bacteroides, Lactobacilli, Bifidobacteria and Clostridium perfringens (C. perfringens) in the feces of 52 obese participants [body mass index (BMI): ≥ 28 kg/m(2)] and 52 participants of normal-weight (BMI: 18.5-24 kg/m(2)) were obtained. Study participants completed comprehensive questionnaires and underwent clinical laboratory tests. The polymerase chain reaction-restriction fragment length polymorphism (PCR-PFLP) assay was used to analyze PPAR-γ2 gene Pro12Ala variation. RESULTS: The obese group exhibited a lower amount of C. perfringens (6.54 ± 0.65 vs 6.94 ± 0.57, P = 0.001) and Bacteroides (9.81 ± 0.58 vs 10.06 ± 0.39, P = 0.012) than their normal-weight counterparts. No major differences were observed in Pro12Ala genotype distribution between the two groups; however, obese individuals with a Pro/Ala genotype had a significantly lower level of Bacteroides (9.45 ± 0.62 vs 9.93 ± 0.51, P = 0.027) than those with a Pro/Pro genotype. In addition, the obese group demonstrated a higher stool frequency (U = 975, P < 0.001) and a looser stool (U = 1062, P = 0.015) than the normal-weight group. CONCLUSION: Our results indicated interactions among cultivable gut flora, host genetic factors and obese phenotype and this might be helpful for obesity prevention.

[Study on polymorphism of UCP2 gene in Chengdu simple obesity and normal-weight people and a preliminary investigation of its relationship with gut bacteria].

OBJECTIVE: To study on the polymorphism of UCP2 gene in Chengdu simple obesity and normal-weight people and to initially investigate the relationship between UCP2 Ala55Val variation and gut bacteria. METHODS: PCR-PFLP was applied to determine the genotypes of Ala55Val variant in the UCP2 gene of 86 Chengdu people (the simple obesity group, 43 subjects; the normal-weight group, 43 subjects). And six kinds of gut bacteria among different genotypes in different groups were analyzed. RESULTS: Both the simple obesity and the normal-weight group had the Ala55Val variants of Ala/Ala, Val/Val and Ala/Val in the UCP2 gene, and the Ala55Val genotype distributions between the two groups was significantly different (chi2=11.97, P< 0.05). The allelic mutation frequency in the simple obesity group was higher than that of the normal-weight group (chi2=10.06, P<0.05). However, no significant difference was observed in the population of six gut bacteria among different genotypes in different groups (P>0.05). CONCLUSION: The UCP2 gene mutation might be a risk factor of obesity in Chengdu area. However, this gene mutation may not be an impact factor on the alternation of gut bacteria.