Application of molecular epidemiology in revealing HIV-1 transmission network and recombination patterns in Tianjin, China.

Using a comprehensive molecular epidemiological approach, we characterized the transmission dynamics of HIV-1 among the MSM population in Tianjin, China. Our findings revealed that 38.56% (386/1001) of individuals clustered across 109 molecular transmission clusters (TCs), with MSM aged 50 and below being the group most commonly transmitting HIV-1. Among the identified TCs, CRF01_AE predominated, followed by CRF07_BC. Notably, CRF07_BC demonstrated a higher propensity for forming large clusters compared to CRF01_AE. Birth-death skyline analyses of the two largest clusters indicated that the HIV/AIDS transmission may be at a critical point, nearly all had Re approximately 1 by now. A retrospective analysis revealed that the rapid expansion of these large clusters was primarily driven by the introduction of viruses in 2021, highlighting the crucial importance of continuous molecular surveillance in identifying newly emerging high-risk transmission chains and adapting measures to address evolving epidemic dynamics. Furthermore, we detected the transmission of drug-resistant mutations (DRMs) within the TCs, particularly in the CRF07_BC clusters (K103N, Y181C, and K101E) and CRF01_AE clusters (P225H and K219R), emphasizing the importance of monitoring to support the continued efficacy of first-line therapies and pre-exposure prophylaxis (PrEP). Recombination analyses indicated that complex recombinant patterns, associated with increased amino acid variability, could confer adaptive traits to the viruses, potentially providing a competitive advantage in certain host populations or regions. Our study highlights the potential of integrating molecular epidemiological and phylodynamic approaches to inform targeted interventions.

HIV infection status and related factors in men who have sex with men in sentinel surveillance in Tianjin, 2016-2018 / 中华流行病学杂志

Objective@#To understand the HIV infection status and related factors in men who have sex with men (MSM) in Tianjin during 2016-2018.@*Methods@#According to the sentinel surveillance protocol, continuous cross-sectional studies were conducted to collect the information about the awareness of AIDS, related behaviors, HIV infection, syphilis prevalence and HCV infection in the MSM in Tianjin with the annual sample seize of 400 between April and June during 2016-2018.@*Results@#From 2016 to 2018, a total of 1 200 MSM were surveyed. The condom use rate in anal sex was 45.4% (544/1 198) in the past 6 months. The HIV test rate in MSM recruited through network declined with year (trend χ2=42.742, P<0.001). The overall HIV infection rate was 3.3% (40/1 200). The HIV-1 infection rate was 2.6% (95%CI: 1.7%-3.5%). The overall prevalence rate of syphilis was 6.7% (80/1 200). The overall HCV infection rate was 0.8% (9/1 200). Results from multivariate logistic regression analysis showed that the risk factors associated with HIV infection in the MSM included divorced or widowed (compared with unmarried, aOR=7.137, 95%CI: 1.621-31.419) and syphilis positive group (compared with syphilis negative group, aOR=3.684, 95%CI: 1.520-8.932). The protective factors for HIV infection in the MSM included consistent use of condom in the past 6 months (compared with occasional use of condom, aOR=0.343, 95%CI: 0.126-0.932) and HIV test (compared with receiving no HIV test, aOR=0.314, 95%CI: 0.123-0.801).@*Conclusions@#The HIV infection rate in the MSM in Tianjin was high from 2016 to 2018. Syphilis prevalence status in MSM should not be neglected. The rate of consistent condom use in anal sex was low in the MSM. It is necessary to take effective measures to promote condom use and strengthen HIV test in MSM.

The characteristics of recent HIV-1 infection and associated factors in Tianjin / 中华预防医学杂志

The newly reported HIV infected cases was collected, and HIV blood samples were detected to identify recent HIV infection in Tianjin during 2008-2015. Factors associated with HIV-1 infection were analyzed by the univariate and multivariate unconditional logistic regression. The recent HIV-1 infection proportion of homosexuals increased from 37.70% in 2008 to 83.68% in 2015. Those cases who aged ≤30 years (OR=1.53, 95%CI: 1.30-1.79), in han ethnic group (OR=1.40, 95%CI: 1.02-1.91), students (OR=1.79, 95%CI: 1.28-2.51) were more likely to be recent infected. The cases who had a high school education (OR=1.28, 95%CI: 1.05-1.56) or collage education (OR=1.23, 95%CI: 1.00-1.50) were more likely to be recent infected than those who had a primary school education. Compared with patients identified by hospitals, the recent HIV infections were more likely to be found through voluntary counseling and testing (VCT), STD outpatients, men who have sex with men (MSM) investigation and unpaid blood donors. Homosexual transmission has become the major route of HIV-1 recent infection in Tianjin.

Transmitted drug resistance among HIV infected men who have sex with men in Tianjin,2014-2017 / 中华流行病学杂志

Objective To understand prevalence and transmission of transmitted drug resistance (TDR) among HIV infected men who have sex with men (MSM) in Tianjin from 2014 to 2017.Methods A total of 225 blood samples were collected from HIV infected MSM in Tianjin from 2014 to 2017.Pol gene fragments were obtained by viral RNA extraction and nested PCR amplification.Phylogenetic and drug resistance analyses were conducted.Results A total of 205 samples were successfully sequenced and analyzed.Based on pol sequences,53.2％ (109/205),28.8％ (59/205),10.2％ (21/205),4.9％ (10/205) and 2.9％ (6/205) of the samples were positive for HIV subtypes CRF0 1_AE,CRF07_BC,B,CRF55_01B and unique recombinant forms (URFs).Twenty transmission clusters,including 75 sequences,were identified and 62.5％ (10/16) of sequences with TDR were in 5 clusters.The prevalence of TDR was 7.8％ between 2014 and 2017.The annual prevalence rate increased from 3.9％ (2/51) in 2014,5.7％ (3/53) in 2015,9.6％ (5/52) in 2016 to 12.2％(6/49) in 2017,the difference was not significant (x2=2.504,P=0.127).CRF01_AE and B strains had high TDR prevalence (3.4％,7/205) and (2.9％,6/205),respectively.The TDR mutation was mainly NNRTIs,the TDR prevalence was 6.3％ (13/205).In contract,the TDR prevalence of NRTIs and PIs were 1.5％ (3/205) and 1.0％ (2/205) respectively.Conclusion Results from this study suggested that the prevalence of HIV-1 TDR strains in MSM was serious in Tianjin.It is necessary to take effective prevention and control measures.

Study on acute HIV-1 infection in men who have sex with men in Tianjin / 中华流行病学杂志

Objective To understand the immunological and virological characteristics of HIV-1 infected men who have sex with men (MSM) in the acute phase in Tianjin and evaluate the effects of the fourth generation HIV ELISA and the P24 ELISA for acute HIV-1 infected samples.Methods From October 2015 to October 2016,MSM were recruited through the community-based organizations in Tianjin.All the participants received rapid HIV test,positive samples were confirmed by Western Blot and negative samples underwent pooled nucleic acid testing.The participants with HIV-1 RNA reactive result underwent testing for viral load and T-cell count after second blood collection.Acute HIV-1 infection was defined as negative rapid HIV test result and the positive results of two HIV RNA tests,then the sensitivity were compared between the fourth generation HIV ELISA and the P24 ELISA to detect the initial HIV-1 RNA positive samples.Results Among 3 016 MSM screened,193 were positive in rapid HIV test.Western blot testing indicated that 179 cases were HIV positive,7 cases were HIV indeterminate and 7 eases were negative.Of 2 823 sero-negative cases,17 were acute HIV-1 infections.The HIV-1 infection rate was 6.53％ (197/3 016) and the acute HIV-1 infection rate was 0.56％ (17/3 016),with an average viral load of (5.63 ± 1.50) log10 copies/ml,an average CD4 count of (442.82 ± 268.17) cells/μl,an average CD8 count of (1 069.65 ± 668.22) cells/μl and an average CD4/CD8 ratio of (0.49 ± 0.25).Higher viral load,CD4 and CD4/CD8 ratio were seen in the acute HIV-1 infection group compared with the chronic HIV-1 infection group (U=148,P＜0.01;U=272,P=0.042 and t=3.147,P=0.005).Demographic characteristics were similar between two groups,except the occupation (x2=11.016,P=0.026).The sensitivity of P24 ELISA was higher than the fourth generation HIV ELISA in the H1V-1 detection for acute infection (Fisher's exact test,P=0.017).Conclusions MSM are at risk for acute HIV-1 infection.Screening for acute HIV-1 infection with P24 ELISA would increase the sensitivity of diagnosis and reduce HIV transmission in MSM.

Transmitted drug resistance among HIV infected men who have sex with men in Tianjin, 2014-2017 / 中华流行病学杂志

Objective: To understand prevalence and transmission of transmitted drug resistance (TDR) among HIV infected men who have sex with men (MSM) in Tianjin from 2014 to 2017. Methods: A total of 225 blood samples were collected from HIV infected MSM in Tianjin from 2014 to 2017. Pol gene fragments were obtained by viral RNA extraction and nested PCR amplification. Phylogenetic and drug resistance analyses were conducted. Results: A total of 205 samples were successfully sequenced and analyzed. Based on pol sequences, 53.2% (109/205), 28.8% (59/205), 10.2% (21/205), 4.9% (10/205) and 2.9% (6/205) of the samples were positive for HIV subtypes CRF01_AE, CRF07_BC, B, CRF55_01B and unique recombinant forms (URFs). Twenty transmission clusters, including 75 sequences, were identified and 62.5% (10/16) of sequences with TDR were in 5 clusters. The prevalence of TDR was 7.8% between 2014 and 2017. The annual prevalence rate increased from 3.9% (2/51) in 2014, 5.7% (3/53) in 2015, 9.6% (5/52) in 2016 to 12.2%(6/49) in 2017, the difference was not significant (χ(2)=2.504, P=0.127). CRF01_AE and B strains had high TDR prevalence (3.4%, 7/205) and (2.9%, 6/205), respectively. The TDR mutation was mainly NNRTIs, the TDR prevalence was 6.3% (13/205). In contract, the TDR prevalence of NRTIs and PIs were 1.5% (3/205) and 1.0% (2/205) respectively. Conclusion: Results from this study suggested that the prevalence of HIV-1 TDR strains in MSM was serious in Tianjin. It is necessary to take effective prevention and control measures.

Study on acute HIV-1 infection in men who have sex with men in Tianjin / 中华流行病学杂志

Objective: To understand the immunological and virological characteristics of HIV-1 infected men who have sex with men (MSM) in the acute phase in Tianjin and evaluate the effects of the fourth generation HIV ELISA and the P24 ELISA for acute HIV-1 infected samples. Methods: From October 2015 to October 2016, MSM were recruited through the community-based organizations in Tianjin. All the participants received rapid HIV test, positive samples were confirmed by Western Blot and negative samples underwent pooled nucleic acid testing. The participants with HIV-1 RNA reactive result underwent testing for viral load and T-cell count after second blood collection. Acute HIV-1 infection was defined as negative rapid HIV test result and the positive results of two HIV RNA tests, then the sensitivity were compared between the fourth generation HIV ELISA and the P24 ELISA to detect the initial HIV-1 RNA positive samples. Results: Among 3 016 MSM screened, 193 were positive in rapid HIV test. Western blot testing indicated that 179 cases were HIV positive, 7 cases were HIV indeterminate and 7 cases were negative. Of 2 823 sero-negative cases, 17 were acute HIV-1 infections. The HIV-1 infection rate was 6.53% (197/3 016) and the acute HIV-1 infection rate was 0.56% (17/3 016), with an average viral load of (5.63±1.50) log(10) copies/ml, an average CD(4) count of (442.82±268.17) cells/μl, an average CD(8) count of (1 069.65±668.22) cells/μl and an average CD(4)/CD(8) ratio of (0.49±0.25). Higher viral load, CD(4) and CD(4)/CD(8) ratio were seen in the acute HIV-1 infection group compared with the chronic HIV-1 infection group (U=148, P<0.01; U=272, P=0.042 and t=3.147, P=0.005). Demographic characteristics were similar between two groups, except the occupation (χ(2)=11.016, P=0.026). The sensitivity of P24 ELISA was higher than the fourth generation HIV ELISA in the HIV-1 detection for acute infection (Fisher's exact test, P=0.017). Conclusions: MSM are at risk for acute HIV-1 infection. Screening for acute HIV-1 infection with P24 ELISA would increase the sensitivity of diagnosis and reduce HIV transmission in MSM.

Behaviors on drug-abuse and prevalence of sexually transmitted diseases among drug users in Tianjin, China, from 2011 to 2015 / 中华流行病学杂志

Objective To understand the change of behavioral characteristics among drug users (DUS) in Tianjin and the prevalence rates of major sexually transmitted disease infections.A series of cross-sectional surveys were used.Methods Between April and June,2011 to 2015,a cross-sectional survey with face to face interview,was undertaken.Interview was conducted among DUS who entered the drug rehabilitation center and blood samples were drawn to test for HIV/syphilis/ HCV infections.Multivariate logistic regression analysis was used to analyze the relationship between the infection of major sexually transmitted diseases and drug abuse or sexual behavior.Results 2 000 DUS were included during the 5-year study,with the average age of the DUS as 34.5 ± 8.7.Female accounted for 17.9％ and club drug (new drugs) users accounted 45.4％ of the participants,with its proportion increasing over the years.Comparing to traditional drug users,club drug users showed more sexual activities with partners,but lower proportion of condom use.Prevalence rates of HIV/ Syphilis and HCV were 1.3％,11.0％,52.0％,respectively.The prevalence of syphilis among club drug users was significantly higher than those on traditional-drug use (x2=67.778,P＜0.001).Data from Binary logistic regression analysis showed that club drug use (adjusted OR=1.607,95％ CI:1.191-2.170) and females (adjusted OR=5.287,95％ CI:3.824-7.311) were associated with syphilis infection among DUS.Conclusion Drug abuse behavior changed among the drug abuse in Tianjin.Proportion of club drug use continued to increase so as the risk of infected sexually transmitted diseases.

Study of auxiliary diagnostic value of viral load test for samples with indeterminate HIV antibody detection results / 中华流行病学杂志

Objective To evaluate the auxiliary diagnostic value of viral load test for samples with indeterminate HIV antibody detection results.Methods Thirty-two samples with indeterminate HIV antibody detection results collected from MSM were used for two viral load tests in Tianjin in 2015.Follow up was conducted for this population to confirm their HIV infection status.Results Virus loads were detected in the 2 viral load tests.In the follow-up survey,the results of HIV antibody test of all the samples were positive.The results of viral load test were completely consistent with those of HIIV antibody confirmation test.Conclusion The viral load test was effective in the auxiliary diagnosis of HIV infection in window phase,which can be used for the samples with indeterminate HIV antibody detection results.

Molecular epidemiology and transmission of HIV in Tianjin, 2015 / 中华流行病学杂志

Objective To understand the characteristics on the diversity of HIV subtypes and related transmission in Tianjin.Methods A total of 77 newly diagnosed ART-na(i)ve HIV infectors in 2015 were screened by CD4 +T cell counts ≥200 cells/μl.Viral RNAs were extracted from plasma samples.Reverse transcription PCR and nested PCR were used to analyze the amplification of pol and env gene fragments,sequencing,and related bioinformatics information.Results 46.03％ (29/63),30.16％ (19/63),11.11％ (7/63),4.76％ (3/63) and 7.94％ (5/63) of the individuals were infected under HIV subtypes CRF01_AE,CRF07_BC,B,CRF55_01B and URFs,with sexual transmission as the major mode of infection.CRF01_AE and CRF07_BC strains were predominant in both MSM and HST populations.The patterns of subtype distribution did not show statistical differences other than subtype B and CRF55_01B strain among HSTs.The proportion of CRFs increased significantly to 88.89％.8 new second-generation recombinant forms were identified the first time,including 3 CRF55_01B,2 AE/BC,1 AE/B and 1AE/B/C among MSMs and 1 AE/BC among HSTs.5.3％ of the NNRTI L100I HIV infectors transmitted the drug-resistant-mutation strain.3 linkages related to HIV transmission were confirmed through phylogenetic analysis with Bootstrap ≥98％ of pol and ≥80％of env.Conclusion The increasing complexity of HIV had been noticed in Tianjin,including the prevalence and transmission of second-generation recombinant and drug-resistant strains through different routes of transmission and in different regions.

Behaviors on drug-abuse and prevalence of sexually transmitted diseases among drug users in Tianjin, China, from 2011 to 2015 / 中华流行病学杂志

Objective To understand the change of behavioral characteristics among drug users (DUS) in Tianjin and the prevalence rates of major sexually transmitted disease infections.A series of cross-sectional surveys were used.Methods Between April and June,2011 to 2015,a cross-sectional survey with face to face interview,was undertaken.Interview was conducted among DUS who entered the drug rehabilitation center and blood samples were drawn to test for HIV/syphilis/ HCV infections.Multivariate logistic regression analysis was used to analyze the relationship between the infection of major sexually transmitted diseases and drug abuse or sexual behavior.Results 2 000 DUS were included during the 5-year study,with the average age of the DUS as 34.5 ± 8.7.Female accounted for 17.9％ and club drug (new drugs) users accounted 45.4％ of the participants,with its proportion increasing over the years.Comparing to traditional drug users,club drug users showed more sexual activities with partners,but lower proportion of condom use.Prevalence rates of HIV/ Syphilis and HCV were 1.3％,11.0％,52.0％,respectively.The prevalence of syphilis among club drug users was significantly higher than those on traditional-drug use (x2=67.778,P＜0.001).Data from Binary logistic regression analysis showed that club drug use (adjusted OR=1.607,95％ CI:1.191-2.170) and females (adjusted OR=5.287,95％ CI:3.824-7.311) were associated with syphilis infection among DUS.Conclusion Drug abuse behavior changed among the drug abuse in Tianjin.Proportion of club drug use continued to increase so as the risk of infected sexually transmitted diseases.

Study of auxiliary diagnostic value of viral load test for samples with indeterminate HIV antibody detection results / 中华流行病学杂志

Objective To evaluate the auxiliary diagnostic value of viral load test for samples with indeterminate HIV antibody detection results.Methods Thirty-two samples with indeterminate HIV antibody detection results collected from MSM were used for two viral load tests in Tianjin in 2015.Follow up was conducted for this population to confirm their HIV infection status.Results Virus loads were detected in the 2 viral load tests.In the follow-up survey,the results of HIV antibody test of all the samples were positive.The results of viral load test were completely consistent with those of HIIV antibody confirmation test.Conclusion The viral load test was effective in the auxiliary diagnosis of HIV infection in window phase,which can be used for the samples with indeterminate HIV antibody detection results.

Molecular epidemiology and transmission of HIV in Tianjin, 2015 / 中华流行病学杂志

Objective To understand the characteristics on the diversity of HIV subtypes and related transmission in Tianjin.Methods A total of 77 newly diagnosed ART-na(i)ve HIV infectors in 2015 were screened by CD4 +T cell counts ≥200 cells/μl.Viral RNAs were extracted from plasma samples.Reverse transcription PCR and nested PCR were used to analyze the amplification of pol and env gene fragments,sequencing,and related bioinformatics information.Results 46.03％ (29/63),30.16％ (19/63),11.11％ (7/63),4.76％ (3/63) and 7.94％ (5/63) of the individuals were infected under HIV subtypes CRF01_AE,CRF07_BC,B,CRF55_01B and URFs,with sexual transmission as the major mode of infection.CRF01_AE and CRF07_BC strains were predominant in both MSM and HST populations.The patterns of subtype distribution did not show statistical differences other than subtype B and CRF55_01B strain among HSTs.The proportion of CRFs increased significantly to 88.89％.8 new second-generation recombinant forms were identified the first time,including 3 CRF55_01B,2 AE/BC,1 AE/B and 1AE/B/C among MSMs and 1 AE/BC among HSTs.5.3％ of the NNRTI L100I HIV infectors transmitted the drug-resistant-mutation strain.3 linkages related to HIV transmission were confirmed through phylogenetic analysis with Bootstrap ≥98％ of pol and ≥80％of env.Conclusion The increasing complexity of HIV had been noticed in Tianjin,including the prevalence and transmission of second-generation recombinant and drug-resistant strains through different routes of transmission and in different regions.

Normal Reference Values of Peripheral Blood CD4 and CD8 Lymphocytes for the Healthy Population in Tianjin / 中国慢性病预防与控制

Objective To establish the normal reference ranges of peripheral blood CD4 and CD8 lymphocytes for the healthy population in Tianjin. Methods 366 samples were recruited from among local physical examination adults and their absolute and proportional values for the ranges of CD4 and CD8 lymphocytes were detected by quantitative flow cytometry with fluorescence labeled antibodies. Results Mean absolute values were (860.27?255.15) cells/?l for CD4 T cells,(671.60?371.39) cells/?l for CD8 T cells and (1.44?0.62) for CD4/CD8 ratio; and the proportional values were (37.05?7.42)% for CD4 T cells,(28.42?7.46)% for CD8 T cells. Our results showed no differences between gender and age on CD4 T cell counts among the healthy adult population in Tianjin. Conclusions There is difference in CD4 T lymphocyte counts in different areas.

Protective Effects of Fucose and Vitamin E on Immune Suppression Caused by Chemotherapy in Model Mice / 中国慢性病预防与控制

Objective To explore the protective effects of the combination of fucose and vitamin E on immune suppression caused by chemotherapy in model mice.Methods firstly,the model mice with lung adenoma were induced by urethane.Then the combination of fucose and vitamin E were administered to the mice after taking chemotherapy.T lymphocyte subpopulation and interleukin-2 concentration were detected by FCM to observe the change of immune function of the mice.Results Compared with chemotherapy control group,the combination of fucose and vitamin E could increase the percent of CD3+,CD4+,ratio of CD4+/CD8+ and the concentration of interleukin-2,but decrease the percent of CD8+.Conclusion The combination of fucose and vitamin E can obviously reduce the immune suppression caused by chemotherapy in mice.