Prevalence of HCV Antibody and its Associated Factors: A Study from Sentinel Hospitals in China.

Objective: The prevalence and related factors of serum anti-HCV in different regions and hospitals have not been studied extensively in China. We used routine screening data to determine the prevalence of HCV antibody in hospital patients, evaluate the epidemic trend of hepatitis C and formulate screening strategies. Methods: Patient information and HCV antibody testing results were collected from January 2017 to December 2019 in 77 HCV sentinel hospitals in China. Univariate and multivariate logistic regression was used to determine the characteristics and associations. Results: HCV antibody prevalence rates were distinct among patients in different departments, with a range of 0.33%-6.93%. Patients who were admitted to the liver disease-related departments (a OR = 10.76; 95% CI, 10.27-11.28), Internal Medicine (a OR = 2.87; 95% CI, 2.75-3.00), and Department of Surgery (a OR = 1.95; 95% CI, 1.87-2.04), were more likely to be tested for HCV antibody positive. HCV antibody prevalence was associated with patients aged 45 years and older (a OR = 2.74; 95% CI, 2.69-2.80), testing in infetious disease hospitals (a OR = 2.33; 95% CI, 2.26-2.40) and secondary hospitals (a OR = 1.72; 95% CI, 1.69-1.75). Patients in sentinel hospitals of the Northeast (a OR = 12.75; 95% CI, 12.40-13.11), the Central (a OR = 1.65; 95% CI, 1.61-1.70), and the West (a OR = 1.78; 95% CI, 1.73-1.83) China had higher HCV prevalence than those who were in the Eastern coastal area. Conclusion: Those who were over 45 years old and saw doctors for liver diseases, and invasive diagnosis and treatment should be referred to HCV antibody testing.

[Situation on HIV/AIDS epidemics among migrant population in China, 2008 - 2011].

OBJECTIVE: To analyze the HIV/AIDS epidemics situation among migrant population. METHODS: Data on HIV/AIDS cases among mobile population through case reporting system was collected from 2008 to 2011. RESULTS: The number of reported cases on HIV/AIDS among mobile population had been rising, with proportions of the total reported cases increased from 10.2% in 2008, to 18.2% in 2011. Sexual contacts continued to be the major route of transmission. With the increasing proportion of homosexual transmission, HIV/AIDS cases among mobile population moved from high HIV-prevalence areas in the western and central parts to low HIV-prevalence areas in the eastern part of the country. CONCLUSION: In recent years, the number of HIV/AIDS cases among mobile population was increasing in the case reporting system. Data showed that some male rural migrants had been engaged in commercial sex activities that called for more effective intervention measures to be taken to reduce the new HIV/AIDS infections in the migrant population.

[Epidemic characteristics of HIV/AIDS among men who have sex with men from 2006 to 2010 in China].

OBJECTIVE: To analyze the epidemic characteristics of HIV/AIDS among men who have sex with men (MSM) from 2006 to 2010 in China, and to provide evidence for the development of prevention and control measures. METHODS: Through the network reporting information system. The distribution of MSM transmission was analyzed. Through sentinel surveillance system from 2006 to 2010, data was gathered and analyzed for HIV/AIDS positive rates and condom use to describe the epidemic characteristics of HIV/AIDS among MSM. RESULTS: Data from HIV/AIDS case reporting system showed that the proportion of MSM transmission was on the rise (from 1.5% in 2006 to 10.8% in 2010), becoming the fastest growth of spreading. Compared with other routes of spreading, MSM transmission showed the following obvious characteristics: 15 to 29 years olds (54.6%), having higher culture background (senior high school graduated or above accounting for 69.8%), unmarried (64.8%), being cadres/teacher/doctor/retirees and students (accounted for 14.3% and 7.9%), with high mobility floating population (36.2%), being urban population (72.6%), having history of blood donation without payment (26.7% and 6.4%). In terms of location, they mainly lived in provinces as Beijing, Sichuan, Guangdong, Chongqing, Jiangsu, Zhejiang, Shanghai and Liaoning where economics were more developed. Data from HIV/AIDS sentinel surveillance system showed that, from 2006 to 2010, the HIV positive anti-body detection rate (median) was 3.4% among MSM in this country, much higher than among the female sex workers. Rate on condom usage (median) was 73.2%, lower than among the female sex workers. CONCLUSION: The proportion of HIV transmission among MSM was on the rapid rise from 2006 to 2010 in China. Through HIV/AIDS sentinel surveillance system, we found that the infection rate was high but the rate of condom usage was low among MSM. Factors as being 15 to 29 years olds, students and blood donors should be under major concern.

[Study on the HIV infection status, characteristics of AIDS-related behaviors and risk factors among men attending the sexually transmitted disease clinics].

OBJECTIVE: To understand the status on AIDS awareness, AIDS-related behaviors, risk factors on HIV infection status among 15 - 90 years or older men at the sexually transmitted disease clinics. METHODS: Data from the 2009 and 2010 national sentinel surveillance system, regarding men attending sexually transmitted disease clinics was collected from Guangdong, Guangxi, Henan, Sichuan, Yunnan and Jiangxi provinces, where the AIDS epidemic among 15 - 90 years or older population was serious. Data was uploaded to National Center for AIDS/STD Control and Prevention (NCAIDS) through the comprehensive AIDS control and prevention information system. Data was then analyzed by SPSS 18.0. RESULTS: A total of 64 003 pieces of data were collected. Among them, 8783 (13.7%) were related to men at ≥ 50 years or older, and to men 15 - 49 years older were 55 220. The rates on the awareness of AIDS knowledge were from 69.6% vs. 80.1%, on frequently having had commercial sexual contacts in the last three months were between 34.1% vs. 36.6%, on having had casual sexual contact in the last three months were 18.7% vs. 28.4%, on having had homosexual anal intercourse as 0.7% vs. 1.4%. The rates of taking HIV antibody testing in the last year (14.3% vs. 17.1%) among this population were all significantly lower than the rate among the 15 to 49 years age group. However, the HIV-positive rate among the older age group (fifty years of age or older) was significantly higher than the rate among 15 to 49 year age group (1.1% vs. 0.7%). Regard the fifty years of age or older men. Data from the multivariate logistic regression analysis demonstrated that factors as: having regular partner (OR = 0.588, P = 0.034), having homosexual anal intercourse (OR = 5.226, P = 0.006) were associated with positivities of HIV antibody. CONCLUSION: High-risk sexual behaviors, including homosexual anal intercourse were the major risk factors for men at ≥ 50 years or older age, related to the infection of HIV.

[HIV/AIDS epidemic situation and data analysis among young students from 2006-2009 in China].

OBJECTIVE: To analyze the HIV/AIDS epidemic situation and related behavioral components among young students in the last years and to provide information for integrated control and prevention programs. METHODS: Data on young students (15 - 24 years) through case reporting system was collected from 2006 to 2009 and continuous sentinel surveillance data regarding 6 national sentinel sites carried out from 2006 to 2009 was also collected. The sentinel sites would include universities, junior college and secondary vocational colleges registered students, using cluster sampling phases method. Self-administered questionnaire survey and blood (HIV antibody testing and syphilis antibody testing) tests were carried out, with the sample size was about 800 cases per site per year. RESULTS: The number of case report on HIV/AIDS among the young students of 15 - 24 years age group had been rising. Similar trend was also observed on the number of reported cases over the years, accounting for the proportions of the total number of reported cases, as 0.39%, 0.50%, 0.83% and 1.02% respectively from 2006 to 2009. Sexual contacts continued to be the major route of transmission, with the increasing proportion of homosexual transmission. In the 6 national sentinel sites of young students which continuous surveillance was conducted during the period from 2006 to 2009, data showed the following facts as: proportion (median) of objects who admitted to have had sex, were: 4.3%, 4.5% and 6.1%, proportions (median) of commercial sex occurred in the past year were: 0.3%, 0.2% and 0.3%; proportions (median) of MSM occurred in the past year were: 0.7%, 0.2% and 0.2%; median of HIV antibody positive rate and syphilis antibody positive rate were 0%; median of awareness rate on HIV/AIDS were: 49.0%, 75.0% and 80.5%; proportion (median) of monitor objects who received intervention services in the past year were: 44.2%, 54.3% and 50.2% respectively. CONCLUSION: In recent years, the HIV/AIDS number through case reporting system on the young students under 15 - 24 years age group, was increasing, but the HIV prevalence among young students was still relatively low, in general. The main transmission was sexual. Some young students had been engaged in commercial sex and MSM activities. Health education should be strengthened to increase the awareness of young students on AIDS/STD prevention. It is necessary to take more effective intervention measures to decrease new infection and control HIV/AIDS epidemic among young students.

[Data analysis of national HIV comprehensive surveillance sites among female sex workers from 2004 to 2008].

OBJECTIVE: To monitor the time trend of behaviors change related to HIV/AIDS epidemic and HIV prevalence, and to provide information and basis for comprehensive HIV prevention responses and evaluation of intervention effectiveness among female sex workers in China. METHODS: During the year of 2004 to 2008, a series of cross-sectional surveys were conducted among female sex workers in community recruited in both entertainment places and in street, during the defined timeframe, a face-to-face interview was conducted with uniformed questionnaire; while, the venous blood specimen was collected. The sample size was 400 per site per survey. RESULTS: In 15 continuous national HIV comprehensive surveillance sites among female sex workers from 2004 to 2008, the median of HIV prevalence was 0.0%; Prevalence (median) of syphilis respectively: 0.5%, 1.8%, 1.6%, 1.8% and 1.0%. The median of target subjects who used condom in the last commercial sex was: 81.8%, 80.5%, 84.6%, 87.0% and 88.9% respectively; the median of always used condom in commercial sex during the last month: 65.8%, 59.6%, 60.3%, 59.8% and 73.7%. The median of awareness rate on HIV/AIDS transmission of female sex workers was: 74.3%, 84.1%, 65.2%, 66.0% and 74.3%. The median of target subjects who attended HIV VCT services were: 12.4%, 20.4%, 25.8%, 25.3% and 31.7%. The median of the proportion of female sex workers who reached intervention in last year respectively: 46.4%, 76.1%, 72.1%, 95.0% and 90.8%. CONCLUSION: Condom use and HIV awareness rate need to enhance further among female sex workers. The proportion of female sex workers who attended VCT and knew their HIV testing result and the proportion of female sex workers who reached intervention in last year both increase. HIV prevalence rate among female sex workers is generally low, but high risk behaviors are still alarming. It is necessary to take more comprehensive and effective prevention measures and intervention.

[Viral load test conducive to excluding negative subjects from suspects in HIV antibody detections].

OBJECTIVE: To study whether plasma viral load testing is helpful to exclude ones free from Human immunodeficiency virus (HIV) infections from suspects in HIV antibody detections. METHODS: 19 Specimens, which showed disconcordant results of the two HIV EIA testing (S/CO < 6) and indeterminated results of Western blot (WB) test, were selected. Viral load of the specimens were detected. A six-month follow up survey in detecting HIV antibody was conducted in these subjects. RESULTS: None of these 19 cases was observed to be positive HIV viral loads and there was no any progress in WB bands development during the follow-up period. The possibility of HIV infection could be excluded. CONCLUSION: When the specimens react with very low intensity in both EIA and WB, negative viral load result is conducive to exclude negative subjects from suspects in HIV antibody detections.

[Subtype and sequence analysis of gag and env genes among HIV-1 strains circulating in Beijing residents during 2006].

OBJECTIVE: To investigate the subtype distribution and the prevalence of sequence characteristics of HIV-1 strains in Beijing residents during 2006 and to analyze the relationship between distribution of HIV-1 subtypes and transmission routines. METHODS: Blood samples from 32 new confirmed HIV-1 infected individuals from Beijing residents in 2006 and separated plasma specimens were collected. RNAs were extracted and the gag and env gene were amplified by RT-PCR and nest-PCR. PCR products were sequenced directly and phylogenetic analyses of gag and env gene were performed using the MEGA2 software. RESULTS: Among 32 HIV-1 plasma samples, 22 gag and 4 env gene fragments were amplified and analyzed. Five HIV-1 subtypes or circulating recombinant forms(CRFs) of HIV-1 including Thai B (2 strains), B (9 strains), C (2 strains), CRF07_BC (5 strains), CRF01 AE (4 strains) were identified being circulated in Beijing. The gene divergences of gag gene inside the subtypes were 6.6%, 4.3%, 6.8%, 4.9% and 3.0% in subtype B, Thai B, C, CRF01_AE and CRF07_BC respectively. Subtypes B were predominant in Beijing, accounted for 40.9% among 22 samples. CONCLUSION: Five HIV-1 subtypes were identified in Beijing and the surveillance of HIV-1 gene variation should be paid more attention to.

Field evaluation of alternative testing strategies for the detection of HIV infection in Beijing.

OBJECTIVE: To identify a cost-efficient alternative antibody testing strategy for screening and confirmation of HIV infection by rapid simple tests (RSTs) and enzyme-linked immunosorbent assays (ELISAs). METHODS: Four RSTs (RST1, RST2, RST3, and RST4) and five ELISAs (ELISA1, ELISA2, ELISA3, ELISA4, and ELISA5) were evaluated in two phases by using banked and serum specimens prospectively collected at regional hospitals and voluntary counseling and testing (VCT) centers in Beijing. A total of 200 banked serum specimens were included in the first phase, including 62 HIV-positive, 127 HIV-negative and 11 indeterminate specimens. All specimens were tested by four RSTs and five ELISAs respectively. The second phase involved prospective testing of 389 routine specimens, including 92 HIV-positive, 287 HIV-negative, and 10 indeterminate specimens. All the specimens were tested by two RSTs (RST2 and RST4) and three ELISAs (ELISA1, ELISA3, and ELISA4), which were selected for their respective excellent sensitivity and/or specificity. Western blot (WB) was used as a gold standard for confirming the reactivity of all the specimens. RESULTS: Sensitivity, specificity, and efficacy were calculated for each assay in two phases. In the first phase, four assays (ELISA4, RST2, RST3, and RST4) had a specificity of 100%. For the determination of efficacy, ELISA4, RST2, and RST4 were selected in the second phase. ELISA1 and ELISA3 which have a sensitivity of 95.9% and 93.2% respectively also entered this phase. In the second phase, all the five assays (ELISA1, ELISA3, ELISA4, RST2, and RST4) had a sensitivity and specifity of over 90%. ELISA1 had a sensitivity of 99% and ELISA4 a specificity of 99%. CONCLUSION: The sensitivity ELISA1 and the specificit of ELISA4 are comparable to ELISA/WB standard strategy. Application of this alternative testing strategy provides a cost-effective method for determining HIV prevalence in Beijing.

Association of neutralization sensitivity of HIV-1 primary isolates with biological properties of isolates from HIV-1 infected Chinese individuals.

OBJECTIVE: Although HIV-1 infection is prevalent in many regions in China, it remains largely unknown on the biological characteristics of dominant circulating isolates. This study was designed to isolate the circulating viral strains from different prevalent regions and to characterize their biological properties and neutralization sensitivity. METHODS: Primary viruses were isolated from fresh PBMCs using the traditional co-culture method and their capacity of inducing syncytium was tested in MT-2 cells. Meanwhile, their coreceptor usage was determined with two cell lines: Magi and GHOST (3) stably expressing CD4 and the chemokine receptor CCR5 or CXCR4. Furthermore, the sensitivity of these viruses to neutralization by HIV-1-infected patients' plasma which were highly active to neutralize SF33 strain, was quantified in GHOST cell-based neutralization assay. RESULTS: Six primary viral strains were isolated from 4 separated regions. Isolates LTG0213, LTG0214 and XVS032691 induced syncytia in MT-2 cells, and used CXCR4 as coreceptor. Isolates XJN0021, XJN0091, or SHXDC0041 did not induce syncytia, and used CCR5 as coreceptor. Overall neutralization sensitivity differed among four representative strains: HIV-1 XVS032691 > LTG0214 >XJN0091 approximately SHXDC0041. CONCLUSION: The neutralization sensitivity of HIV isolates is linked with the phenotype of isolates, in which syncytium-inducing (SI) or CXCR4-tropic (X4) viruses are more easily neutralized than non-syncytium-inducing (NSI) or CCR5-tropic (R5) viruses. The genetic subtypes based on the phylogeny of env sequences are not classical neutralization serotypes.

[Sequence analysis of gag-pol gene of HIV-1 B/C recombinant viruses in China].

OBJECTIVE: To characterize full length gag gene and partial pol gene of Chinese prevalent HIV-1 B/C recombinant strains, to explore the genetic difference between parent strains and B/C recombinant strains, and to investigate the mechanism of different biologic phenotype among them. METHODS: The peripheral blood samples were collected from 138 HIV-positive persons from 12 regions of China respectively. Samples of total DNA were extracted from the peripheral blood mononuclear cells to undergo nested PCR and sequencing. The 117 HIV-1 CRF07-BC strains and 21 HIV-1 CRF08-BC strains were screened with the resulted that 5 CRF07-BC samples from Xinjiang and 1 CRF08-BC sample from Chongqing were regarded as the most potential new type recombinant viruses. The sequences thus obtained underwent phylogenetic tree analysis and amino acid variation analysis. Simplot software was used to analyze the sequence recombination and identify the breakpoints of B/C recombinant strains. To confirm the breakpoints, separate phylogenetic analysis according to the breakpoints was performed with MEGA software. The genetic distances of different gene fragments were calculated by DISTANCE program in GCG software package. The gene dispersion in the gene fragment of a length of 2550 bp of the recombinant HIV-1-B/C and the potential influence of gene recombination on its function were further analyzed. RESULTS: No change of breakpoint was found in the 5 samples from Xinjiang. But a breakpoint shift of 160 nucleotides occurred in RT region of a sample from Congqing city. CONCLUSION: CRF07-BC and CRF08-BC remain the main prevalent HIV-1 B/C recombinant strains in China. No epidemic of new mosaic recombinant strain is found. The variation of amino acids at the sites 286 and 799 may be the reasons of the transmission dominance of the B/C recombinant strain.

[Biological characteristics of HIV-1 isolates circulating in China are linked to its env V3 loop sequence variability].

OBJECTIVE: To investigate the biological characteristics of the HIV-1 isolates circulating in China and to define the association of these properties with env V3 loop sequence variability. METHODS: Primary viruses were isolated from fresh peripheral blood mononuclear cells (PBMCs) using the traditional co-culture method and their capacity of inducing syncytium was tested in MT-2 cells; meanwhile, their coreceptor usage was determined with GHOST-cell lines which stably express CD4 and the chemokine receptor CCR5 or CXCR4. Furthermore, HIV-1 V3 and its flanking region sequences were amplified by nest-polymerase chain reaction (nest-PCR) and sequenced. A GCG software was used to translate the DNA sequences into polypeptide sequences. RESULTS: Five primary viral strains were isolated from 3 different regions in China. The isolates LTG0213 and LTG0214 induced syncytia in MT-2 cells and used CXCR4 as coreceptor. The isolates XJN0021, XJN0091, and SHXDC0041 did not induce syncytia and used CCR5 as coreceptor. There were obvious differences between X4/SI and R5/NSI viruses in env V3 loop sequences. A consensus motif at the positions 8, 11, 18, and 25 in V3 loop was identified as follows: a sequence as "8-TXXS/GXXXXXXR/QXXXXXXE/D-25" will predict the usage of CCR5 coreceptor; a sequence replacing these positions with basic amino acids (except position 25) will very likely predict the usage of CXCR4 coreceptor. CONCLUSION: The biological characteristics of HIV isolates are linked to env V3 loop sequence variability: introducing basic amino acids (or translating from acidic amino acids into neutral amino acids) at the positions 8, 11, 18, and 25 in V3 loop will change viral strain's biological phenotype from NSI/CCR5 to SI/CXCR4. The biological phenotype of HIV-1 can be predicted with V3 loop sequence analysis.