[Characteristics of baseline viral load before antiretroviral therapy in newly reported HIV-infected patients in Tianjin, 2019-2022].

Objective: To understand the baseline viral load (VL) of newly reported HIV- infected patients before antiretroviral therapy and related factors in Tianjin. Methods: Data were obtained from the China Disease Control and Prevention Information System, and the study subjects were HIV-infected patients before the first antiretroviral therapy in Tianjin from 2019 to 2022, and the information about their socio-demographic characteristics, baseline CD4+T lymphocyte (CD4) counts before antiretroviral therapy and baseline VL test results were collected, the baseline high VL was defined as ≥100 000 copies/ml. The effect of different factors on viral load were analyzed. Software SPSS 24.0 was used for statistical analysis. Results: A total of 1 296 newly reported HIV-infected patients were included in the study, in whom 15.89% (206/1 296) had high baseline VL, and multifactorial logistic regression analysis showed that those with history of STD (aOR=1.45, 95%CI:1.00-2.08) were more likely to have high baseline VL. Compared with those with baseline CD4 counts <200 cells/µl, those with baseline CD4 counts 200-350 cells/µl (aOR=0.40, 95%CI: 0.27-0.57), 351-500 cells/µl (aOR=0.32, 95%CI: 0.20-0.49), and >500 cells/µl (aOR=0.30, 95%CI: 0.18-0.49) were less likely to have high baseline VL. Conclusions: The proportion of HIV-infected patients with high baseline VL before antiretroviral therapy was low in Tianjin during 2019-2022. History of STD and baseline CD4 counts <200 cells/µl were associated with high baseline VL in HIV-infected patients, to which close attention needs to be paid in AIDS prevention and control.

[HIV infection status in male outpatients in sexually transmitted disease clinics in Tianjin, 2016-2020].

Objective: To understand the HIV infection status in male outpatients in sexually transmitted disease (STD) clinics in Tianjin from 2016 to 2020. Methods: According to the sentinel surveillance protocol, continuous cross-sectional studies were conducted between April and June during 2016-2020 to collect the information about the awareness of AIDS related knowledge, related sex behaviors, HIV infection, syphilis prevalence and HCV infection of male STD outpatients in Tianjin with a sample seize of 400 in each sentinel clinic. Results: From 2016 to 2020, a total of 4 000 male STD outpatients were surveyed. The HIV positive rate increased from 1.13% (9/800) to 2.25% (18/800) (trend χ2=14.22, P<0.001), the positive rate of syphilis increased from 9.38% (75/800) to 13.00% (104/800) (trend χ2=7.30, P=0.007) in this population during this period. The overall HCV positive rate was 0.45% (18/4 000). Multivariate logistic regression analysis showed that compared with those who were unmarried, had registered residence in Tianjin, had no temporary sexual behavior in the past 3 months, had no anal sex and had negative syphilis test result, the risk factors of HIV infection in the male STD outpatients included cohabitation (aOR=7.53, 95%CI:2.13-26.62), being from other provinces (aOR=3.64,95%CI:1.58-8.38), having temporary sexual behavior in the past 3 months (aOR=2.24,95%CI:1.03-4.89), having homosexual anal sex (aOR=85.99,95%CI:38.76-190.74) and suffering from syphilis (aOR=6.06,95%CI:3.18-11.56). Conclusion: The detection rates of HIV infection and syphilis in male STD outpatients in Tianjin showed upward trends from 2016 to 2020. Having temporary sexual behavior and anal sex, and suffering from syphilis were the main risk factors of HIV infection in male STD outpatients.

[HIV infection status and related factors in men who have sex with men in sentinel surveillance in Tianjin, 2016-2018].

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 χ(2)=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].

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.

[Study on acute HIV-1 infection in men who have sex with men in Tianjin].

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.

[Transmitted drug resistance among HIV infected men who have sex with men in Tianjin, 2014-2017].

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.

[Molecular epidemiology and transmission of HIV in Tianjin, 2015].

OBJECTIVE: To understand the characteristics on the diversity of HIV subtypes and related transmission in Tianjin. METHODS: A total of 77 newly diagnosed ART-naïve 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.

[Study of auxiliary diagnostic value of viral load test for samples with indeterminate HIV antibody detection results].

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.

[Behaviors on drug-abuse and prevalence of sexually transmitted diseases among drug users in Tianjin, China, from 2011 to 2015].

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 (χ(2)=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.