Wende Cai

HIV prevalence and related risk factors among male sex workers in Shenzhen, China: results from a time-location sampling survey.

Background HIV transmission among men who have sex with men has recently become a major concern in China. Little is known, however, about HIV transmission among male sex workers (MSW). This study aimed to investigate HIV infection prevalence and risk factors among MSW in Shenzhen, China. Materials and methods Following formative research, a cross-sectional study was conducted using time–location sampling among MSW in Shenzhen, from April to July 2008. Behavioural and serological data on HIV and syphilis were collected. The risk factors for HIV infection were analysed using a logistic regression model. Results In total, 394 MSW were recruited for the survey. The prevalence of HIV and syphilis among these workers was 5.3% and 14.3%, respectively. Only a quarter of the MSW self-identified as homosexual. More than 70% had sex with both men and women. HIV-related knowledge levels were high regardless of HIV serostatus. Consistent condom use was low (37.1%) and varied by type of sexual partner. Factors including more non-commercial male partners, working in small home-based family clubs, being drunk before sexual intercourse, having a history of HIV tests, syphilis infection and a short period of residence in Shenzhen were associated with an increased risk of HIV infection. Conclusions High-risk sexual practices were common among MSW regardless of their high level of HIV awareness. The working venues were associated with HIV infection and a recent test for HIV was a potential predictor of HIV infection. The time–location sampling method was found to be an appropriate way of recruiting MSW for this study, especially those without fixed working places.

A comparison of HIV infection and related risk factors between money boys and noncommercial men who have sex with men in Shenzhen, China.

Background HIV transmission among men who have sex with men (MSM) has become an increasing concern in China. Money boys (MBs) are a subgroup of MSM who sell sex to men. Direct comparison of HIV prevalence and related risk factors between MB and noncommercial MSM (ncMSM) has rarely been done. This study was conducted to make the comparison. Methods Eight hundred fifty MBs and 801 ncMSM were parallel recruited in Shenzhen by time-location sampling. Their behavioral and serologic data on HIV and syphilis were collected and compared. Multiple logistic regression analysis was performed to evaluate the determinants for HIV risk in MBs and ncMSM, respectively. Results The prevalence of HIV was 4.5% in MBs and 7.0% in ncMSM. Although MBs tended to have more male partners than ncMSM, they were more likely to report a consistent condom use in male anal intercourse, especially in commercial sex. Noncommercial MSM were more likely to visit parks and saunas instead of bars, massage centers, recreational centers, and home-based venues. Syphilis infection and recruitment venue were associated with HIV infection in both MBs and ncMSM. Being from a hometown with a high HIV prevalence and without a male partner from Hong Kong were found to be risk factors for HIV infection in MBs, and early sexual debut was a risk factor in ncMSM. Conclusion Money boys differed from ncMSM in the rate of HIV infection and some sexual characteristics and behaviors. Formatting separate interventions specifically targeting the 2 subgroups may be necessary.

Unprotected anal intercourse behavior and intention among male sex workers in Shenzhen serving cross-boundary male clients coming from Hong Kong, China - prevalence and associated factors.

The HIV epidemic among men who have sex with men (MSM) in China is becoming very serious. Unprotected anal intercourse (UAI) among MSM during cross-boundary commercial sex spread HIV across geographic areas. This study interviewed 186 Chinese male sex workers (MSW) in Shenzhen, China, serving cross-boundary Hong Kong male clients; 49.5% had had UAI with their Hong Kong male clients (last six months) and 24.2% intended to do so (future six months). Multivariate analyses showed that perceived efficacy of condom use for HIV prevention, perceived prevalence of HIV among Hong Kong MSM (>4%), and perceived ability to convince Hong Kong male clients to use condoms during anal sex were associated with lower likelihoods of UAI with such clients (OR = 0.04–0.09); the reverse was true for those who left the decision of condom use to their Hong Kong male clients (OR = 6.44). Perceived condom efficacy, self-efficacy in protection against HIV infection, and perceived control over condom use were associated with an intention for UAI (OR = 0.06–80.44). Adjusting for background variables, the scales representing contextual (Clients Characteristics, Substance Use, or Environmental Influences) and affective factors (Fear of Diseases) were associated with UAI (adjusted OR = 0.44–32.61). Except the Fear of Diseases scale, other scales were associated with an intention for UAI (adjusted OR = 4.59–43.32). MSW are at high risk of HIV transmission. Various factors are associated with UAI with male cross-boundary clients; these factors and the context of sex work need to be considered when designing HIV prevention programs.

Origin and outbreak of HIV-1 CRF55_01B among MSM in Shenzhen, China.

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A comparison of HIV infection and related risks among male sex workers in different venues in Shenzhen, China.

Different risks of HIV infection have been reported among different types of male sex workers (MSW). In order to compare the prevalence of HIV infection and related risk behaviors of MSW in different venues in Shenzhen, China, a time-location sampling survey was conducted in 2008. 5.1% of the 394 MSWs were tested positive for HIV, with 6.9% in those working in parks (PMSW), 11.3% in small family clubs (FMSW) and 1.7% in entertainment venues. PMSWs and FMSWs reported a higher proportion of self-identified homosexual/gay. Moreover, FMSWs reported a lower coverage of HIV-related education and services and were more likely to self-report coming from provinces with higher HIV prevalence. The results indicated that MSWs in small venues and parks were comparatively at higher risk of being infected and suggested that current HIV preventive intervention needs to be expanded to the small venues in Shenzhen.

A Comparison Between Respondent-Driven Sampling and Time-Location Sampling Among Men Who Have Sex with Men in Shenzhen, China

Men who have sex with men (MSM) are a key population for HIV control and prevention in China. It is difficult to acquire representative samples of this hidden population. Respondent-driven sampling (RDS), based on peer referral, and time-location sampling (TLS) based on random selection of venue-day-time periods, are among the most commonly used sampling methods. However, differences in HIV-related characteristics of MSM recruited by these two methods have not been fully evaluated. We compared sociodemographics, risk behaviors, utilization of HIV-related intervention services, and HIV/syphilis infection rates between samples of 621 RDS MSM and 533 TLS MSM in Shenzhen, China in 2010. We found that the HIV prevalence was comparable in RDS and TLS MSM. TLS recruited larger proportions of more marginalized MSM than RDS: MSM recruited by TLS were older, less educated and more likely to be migrants (without Shenzhen hukou registration), to be non-gay identified and to engage in risky sexual behaviors. On the other hand, MSM recruited by TLS were more likely to have been covered by HIV-related intervention services. To conclude, in Shenzhen, TLS is more effective to reach the marginalized population of MSM. But because TLS can only reach MSM who physically attend venues and HIV-related intervention services are already commonly available at gay venues in Shenzhen, RDS is more informative for allocating prevention efforts than TLS. Furthermore, researchers and public health authorities should take into account the different sample compositions of RDS and TLS and apply sampling methods consistently when evaluating trends over time.

The dynamics of the HIV epidemic among men who have sex with men (MSM) from 2005 to 2012 in Shenzhen, China.

HIV-1 epidemics among MSM are a major public health concern in China, especially in large cities. This study sought to better understand the dynamics of HIV molecular epidemiology among MSM in Shenzhen, a rapidly developing city with over 13.8 million people. HIV-1 pol sequences were obtained from 996 (53.5%) of 1862 HIV-infected MSM and 403(9.0%) of 4498 heterosexuals and injection drug users in Shenzhen, China from 2005-2012. Eight HIV-1 subtypes and some inter-subtype recombinants were identified among sampled MSM with CRF07_BC (39.1%) and CRF01_AE (35.1%) being the most predominant. From 2006 to 2012, the prevalence of CRF07_BC and CRF55_01B rapidly increased, while the prevalence of subtypes B and CRF01_AE gradually decreased. The genetic distances within CRF07_BC and CRF55_01B groups were significantly lower than within CRF01_AE and B groups. The vast majority (90.3%) of HIV-1 infected MSM in Shenzhen were migrants who came from 31 of the 34 provinces of China, and these migrants had significantly different HIV-1 subtype distributions from the local MSM. This study highlighted the importance of CRF07_BC and migrants in the changing HIV epidemic among MSM in China, and provides a molecular epidemiology framework for understanding how HIV-1 epidemics can change in large cities with diverse risk groups.

HIV-related risk factors among male sex workers in different settings in Shenzhen, China

Results Among 394 subjects, the prevalence of HIV infection was 5.1%, with 6.9% among MSWs in parks (PMSW), 11.3% among MSWs in family clubs(FMSW, a kind of home-based brothels holding small group of MSWs 15). Syphilis prevalence was 14.2%, with 25.0% in PMSWs, 17.6% in FMSW and 10.6% in EMSWs. Both HIV and syphilis prevalence were significantly different among different type of MSWs. Independent PMSWs and small grouping FMSWs had a higher proportion of self-identifying as homosexual/gay and fewer female sex partners, elder or higher polarization in age. In addition, a higher proportion of MSWs was found coming from provinces with higher HIV prevalence, and lower coverage by HIV-related education program and relevant services. Discussion Different type of male sex work is associated with HIV infection. MSWs working in family clubs and parks are comparatively with higher risk of being infected, while MSWs working in big entertainment venues showed a lowest HIV prevalence within the past few years in Shenzhen. This situation indicated that current HIV prevention intervention strategy that focus on big venues is quiet effective and should be expanded to cover the MSM population frequenting small venues.