[Incidence and risk factors of HIV and syphilis seroconversion among men who have sex with men in Beijing].

OBJECTIVE: To study the incidence and risk factors of HIV and syphilis seroconversion among men who have sex with men (MSM) in Beijing. METHODS: A total of 550 MSM were recruited on the basis of community and followed up after 6 and 12 months in Beijing. Each subject was investigated by only one investigator at one time to collect information on demographics and behaviors. Blood samples were collected to test HIV and syphilis seroconversion. ELISA was used for screening test, west blotting (WB) and Particle agglutination were used for confirmatory test. RESULTS: A total of 550 MSM investigated, among which 4.5% (25/550) were HIV-positive and 29.3% (161/550) were syphilis-positive. For 525 HIV-negative MSM, 87.0% (457/525) retained during the 12-month investigation. Seroincidence for HIV and syphilis were 3.37/100 person-years (95%CI = 1.66 - 5.08) and 9.32/100 person-years (95%CI = 5.87 - 12.77) respectively. HIV seroconversions for those who performed and did not perform rectal douching after homosexual anal intercourse in the past 3 months were 7.11/100 and 0.76/100 person-years respectively. Multivariate Cox regression analysis revealed that rectal douching after homosexual anal intercourse in the past 3 months (HR = 9.23, 95%CI = 2.08 - 40.88) was significantly associated with HIV seroconversion. Syphilis seroconversions for those who met male sex partners in parks, public washrooms or bathhouses in the past 3 months were 41.77/100 and 7.97/100 person-years respectively. Syphilis seroconversions for those who performed and did not perform rectal douching after homosexual anal intercourse in the past 3 months were 16.17/100 and 4.92/100 person-years respectively. In the past 3 months, meeting male sex partners in parks, public washrooms or bathhouses (HR = 4.67, 95%CI = 1.77 - 12.34) and performing rectal douching after homosexual anal intercourse (HR = 3.09, 95%CI = 1.40 - 6.83) were significantly associated with syphilis seroconversion. CONCLUSION: The seroconversions of HIV and syphilis during the follow-up visits in this MSM cohort study in Beijing were very serious, and that the associated factors for seroconversions were rectal douching after homosexual anal intercourse and meeting male sex partners in parks, public washrooms or bathhouses.

[Analysis of gag-specific IFN-gamma secretion responses in HIV-1 B/C recombinant infectors].

OBJECTIVE: To characterize the Gag-Specific T lymphocyte responses and identify immunodominant region recognized in Chinese HIV-1 recombinant subtype B/C infectors. METHODS: 10 antiretroviral treatment (ART) naive HIV-1 recombinant subtype B/C infectors with infected time in 1 year, 25 ART-naive infectors with infected time > 3 years and 10 HIV-1-seronegative healthy individuals were enrolled. HIV-1-specific T lymphocyte responses were analyzed by an IFN-gamma Elispot assay against 123 overlapping peptides spanning HIV-1 Gag protein in the present study. RESULTS: Gag-specific T lymphocyte responses of interferon-gamma secretion were identified in 8(8/10) Chinese HIV-1 recombinant subtype B/ C infectors with infected time in 1 year, the specific T lymphocytes are mainly targeted at five seperated peptides. Responses were identified in 17(68%) infectors with infected time more than 3 years, the specific T lymphocytes are mainly targeted at one peptide in p17 and six in p24. There was obviously positive correlation (P = 0.0318, r = 0.519) between the magnitude of responses and viremia in infectors infected time > 3 years. The magnitude of response in infectors infected in 1 year was significantly higher than group infected time > 3 years (P = 0.021). None of healthy individuals produced positive responses. CONCLUSIONS: HIV-1 recombinant subtype B/C Infectors at different stages of diseases recognize different region of gag.

[Factors associated with retention in a community-based methadone maintenance treatment among heroin addicts].

OBJECTIVE: To explore factors associated with retention in a community-based methadone maintenance treatment (MMT) among heroin addicts in Xichang of Sichuan province. METHODS: All 206 heroin addicts were first admitted to MMT community-based program between March to September 2004. Baseline data of patients characteristics, social function, drug using behaviors, sexual behaviors, dose of methadone and retention were collected. RESULTS: Up to Oct, 2005, all 206 patients contributed 8.98 +/- 5.74 person-months of following-up. The retention rates were 58.7% after 6 months and 34.6% after 12 months respectively. Cox proportional hazard regression model indicated that the employed (HR, 0.60; 95% CI, 0.39 - 0.92), helping family to do housework in past 30 days more than once a day (HR, 0.59; 95% CI, 0.42 - 0.82) and previous self-detoxification > or = 3 times (HR, 0.65; 95% CI, 0.47 - 0.91) were independently associated with retention. CONCLUSION: We should give individual counseling to help heroin addicts increasing compliance.

[Factors associated with retention in a community-based methadone maintenance treatment among drug users in Urumqi, Xinjiang Uigur Autonomous Region].

OBJECTIVE: To explore the factors associated with retention in a community-based methadone maintenance treatment(MMT) among drug users in Urumqi. METHODS: With national MMT guideline( drift) for heroine addicted drug users, local heroine-dependent people were admitted to community-based MMT program affiliated to Xinjiang Uigur Autonomous Region Center for Mental Health. Data on outpatients' social-demo characteristics, baseline behaviors on drug use and daily stabilized dose of drugs were entered to MMT database. RESULTS: Up to 10, Feb. , 2006,353 persons withdrew MMT treatment among 709 heroin dependant drug users. Between 11, Aug., 2005 and 10, Feb., 2006, with median duration as 77 days, cumulative drop-out rate of 90 days and 180 days after first dose of MMT were 73.8% among 455 and 99.4% among 355 drug users, respectively. The incidence of drop-outs was 29.8 per 100 person-month. The median length of stay (days) in MMT was 68.0 (95% CI: 59.0- 78.0). Correlates of retention were found as: Being Uigur(HR = 1.35;95% CI :1.09-1.67), duration of drug use (HR =0.74; 95% CI:0.55-0.99) and stabilized dose(HR = 0.60;95% CI: 0.48-0.74) was found in multiple Cox proportional hazard regression model. CONCLUSION: Retention of MMT among drug users in Urumqi was low. Uigur people should be given individual counseling to help them increase the compliance rate. Within the ranges of clinic dosage, adjustment of the methadone dose on an individual base might serve as an appropriate approach to increase the effectiveness of the program.

[An 1-year prospective cohort study on mortality of injecting drug users].

OBJECTIVE: To study the mortality among injecting drug users (IDUs) from an IDUs cohort in Liangshan of Sichuan province. METHODS: In November 2002, 376 injecting drug users were recruited and followed up for 1 year as part of a prospective cohort study. Socio-demographics and risk behaviors on drug use were recorded. After one year, the mortality rate was estimated and risk factors for mortality were analyzed using Cox regression. RESULTS: Out of the original cohort of 376 participants, there were 28 reported and confirmed deaths during the one year follow-up period. The mortality rate of the cohort was 77.32 per 1000 person-years (95% CI: 48.68 - 105.95) with the standardized mortality ratio (SMR) as 47.62 (95% CI: 31.63 - 68.71). Out of the 28 deaths, 64.3% (18/28) caused by overdoses of drug. No variables were found to be associated with death of all causes, but being un-married and >or= 9 year history of injecting drugs were found to be associated with overdose-related mortality in the final model of Cox regression. The hazard ratios were 4.51 (95% CI: 1.03 - 19.67) and 2.77 (95% CI: 1.10 - 7.00) respectively. CONCLUSION: Overdose served the most frequent cause of deaths in Liangshan of Sichuan province. Future studies should be conducted to focus on mortality and risk factors associated with mortality among IDUs to provide targeted interventions in reducing unnatural mortality.