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Background: Chlamydia causes infertility and increases risk of HIV infection, and population-based studies provide essential information for effective infection control and prevention. This study examined Chlamydia trachomatis prevalence and risk factors among a representative sample of 18-49-year-old residents in Hong Kong. Methods: Census boundary map of 412 constituency areas was used as primary sampling units to construct the sampling frame and, residential buildings and units were randomly selected using geospatial modelling. A questionnaire on sexual practice and health was conducted, and polymerase chain reaction was used to test the urine for genital chlamydial infection. Invitation letters were sent to the selected households and a team of interviewers were sent to recruit one subject per household. Prevalence data was weighted according to the 2011 census and risk factors identified through logistic regression. Results: Among 881 participants (response rate of 24.5%), the overall Chlamydia trachomatis prevalence was low at 1.4% (95%CI 0.8–2.5%) but sexually active young (18–26 years) women had relatively high prevalence (5.8%, 95%CI 1.7–18.2%) in Hong Kong. A unique U-shape disease burden was observed with peaks in younger and older (40–49 years) women. Amongst the sexually active women, the risk factors of Chlamydia trachomatis infection were: younger age (aOR = 25.4, 95% CI 2.81–230); living alone (aOR = 8.99, 95% CI 1.46–55.40); and, among all the sexually active participants, males (including the male partners of the female participants) who had travelled out of Hong Kong in the previous 12 months had higher risks of infection (aOR = 5.35; 95% CI 1.25–22.8). A core-peripheral geographical distribution of Chlamydia trachomatis prevalence was also observed. Conclusion: Young and older sexually active women in Hong Kong have high prevalence of chlamydia. Routine screening for sexually active women and young men should be considered. Further research on testing feasibility and linkage-to-care are urgently needed to control the infection. [ABSTRACT FROM AUTHOR]

Background: Syphilis is prevalent among men who have sex with men (MSM) in China. Syphilis partner notification (PN) programs targeting MSM has been considered as one of effective strategies to prevention and control of the infection in the population. We examined willingness and preferences for PN among MSM to measure feasibility and optimize uptake. Methods: Participation in a syphilis PN program was measured using a factorial survey from both the perspective of the index patient and the partner. Respondents were recruited from April-July 2011 using convenience sampling at two sites—a MSM sexually transmitted disease (STD) clinic and a MSM community based organization (CBO). Respondents first evaluated three factorial survey vignettes to measure probability of participation and then an anonymous sociodemographic questionnaire. A two-level mixed linear model was fitted for the factorial survey analysis. Results: In 372 respondents with mean age (± SD) 28.5 (± 6.0) years, most were single (82.0%) and closeted gays (66.7%). The Internet was the most frequent place to search for sex. Few (31.2%) had legal names for casual partners, but most had instant messenger (86.5%) and mobile phone numbers (77.7%). The mean probability of participation in a syphilis PN program was 64.5% (± 32.4%) for index patients and 63.7% (± 32.6%) for partners. Referral of the partner to a private clinic or MSM CBO for follow-up decreased participation compared to the local Center for Disease Control and Prevention (CDC) or public STD clinic. Conclusions: Enhanced PN services may be feasible among MSM in South China. Internet and mobile phone PN may contact partners untraceable by traditional PN. Referral of partners to the local CDC or public STD clinic may maximize PN participation. [ABSTRACT FROM AUTHOR]

Background: HIV prevalence has increased rapidly among men who have sex with men (MSM) in China reaching alarmingly high levels in some cities. Bisexual MSM have potential to transmit HIV and syphilis to their female partners through condomless vaginal intercourse (CVI). Thus, estimation of the burden of CVI and identification of its associates seemed necessary to control this cross-gender transmission. Method: In a cross-sectional study, using respondent-driven-sampling and snowball sampling, 2958 MSM were recruited from seven Chinese cities, interviewed and tested for HIV and syphilis. Descriptive analysis of the socio-demographic and behaviors followed by simple and multiple logistic regressions [adjusted for income, city, race and social network size to determine adjusted odds ratio (aOR)] were performed using SAS-9.1. Results: Among participating MSM, 19.03% were engaged in CVI. Prevalence of HIV and syphilis among participants involved in CVI were 5.86% and 14.74% respectively. MSM who were older [aOR for aged 40–49 = 2.60 (95% CI: 1.54–4.37)], married [aOR = 6.13 (4.95–7.58)], attended primary school or below [aOR = 3.86 (2.26–6.69)], met male partners at spa/bathhouse/sauna/massage parlor [aOR = 3.52 (2.62–4.72)] and had heterosexual orientation [aOR = 13.81 (7.14–26.70)] were more likely to have CVI. Furthermore, correct knowledge regarding HIV [aOR = 0.70 (0.55, 0.88)] and exposure to HIV prevention interventions [aOR = 0.67 (0.54, 0.82)] were negatively associated with CVI. Conclusions: CVI was found to be common among MSM in China. To minimize the transmission of HIV and syphilis from bisexual MSM to their relatively female partners, targeted interventions should specifically focus on bisexual MSM especially the older and married subgroups. [ABSTRACT FROM AUTHOR]

Background: Sexually Transmitted Infections (STIs) are a global challenge. China, once said to have eradicated STIs, is now facing a rapid rise in the prevalence of HIV/STIs. This review of reviews aims to map HIV/STI risk factors among the Chinese population, with the objective of identifying risk factors to inform the formulation of effective prevention strategies. Methods: A systematic search using key terms related to HIV/STIs, risk factors and the Chinese population in both English and Chinese databases (PubMed, PsycINFO, the Cochrane Library; Wanfang data, CNKI, VIP and SINOMED) was conducted, and peer-reviewed systematic reviews on the topic from 1991 to 2014 were selected. Identified risk factors were grouped into different level determinants based on the HIV Social Epidemiology Model, and then evaluated and reported based on the PRISMA checklist. Findings: Of the twenty-eight reviews included, the majority were focused on well-established, individual level risk factors within key populations, with some highlighting the complexity of interacting factors (e.g., alcohol use and higher income in male migrants). While twenty-two reviews covered individual factors, only ten mentioned social factors and five had contents on structural factors. There are gaps in the evidence on social and structural level impacts of HIV/STIs, such as on stigma, discrimination, health policy, access to care, and illicit drug control policies. Migration and social expectation appear to pose a significant threat in aggravating the HIV/STI situation in China; for example, incarceration patterns indicated a significant risk of HIV/STIs for female sex workers. Conclusions: Since international guidelines recommend an integrated and multi-level approach to HIV/STI prevention, a comprehensive approach targeting interventions at all levels along the continuum of care is needed to effectively curtail HIV/STI transmission in China. More research is needed to better understand the impact of socio-political interventions within a Chinese context. [ABSTRACT FROM AUTHOR]

Background: Sexually transmitted infections (STIs), including Hepatitis B and C virus, are emerging public health risks in China, especially among men who have sex with men (MSM). This study aims to assess the magnitude and risks of STIs among Chinese MSM. Methods: Chinese and English peer-reviewed articles were searched in five electronic databases from January 2000 to February 2013. Pooled prevalence estimates for each STI infection were calculated using meta-analysis. Infection risks of STIs in MSM, HIV-positive MSM and male sex workers (MSW) were obtained. This review followed the PRISMA guidelines and was registered in PROSPERO. Results: Eighty-eight articles (11 in English and 77 in Chinese) investigating 35,203 MSM in 28 provinces were included in this review. The prevalence levels of STIs among MSM were 6.3% (95% CI: 3.5–11.0%) for chlamydia, 1.5% (0.7–2.9%) for genital wart, 1.9% (1.3–2.7%) for gonorrhoea, 8.9% (7.8–10.2%) for hepatitis B (HBV), 1.2% (1.0–1.6%) for hepatitis C (HCV), 66.3% (57.4–74.1%) for human papillomavirus (HPV), 10.6% (6.2–17.6%) for herpes simplex virus (HSV-2) and 4.3% (3.2–5.8%) for Ureaplasma urealyticum. HIV-positive MSM have consistently higher odds of all these infections than the broader MSM population. As a subgroup of MSM, MSW were 2.5 (1.4–4.7), 5.7 (2.7–12.3), and 2.2 (1.4–3.7) times more likely to be infected with chlamydia, gonorrhoea and HCV than the broader MSM population, respectively. Conclusion: Prevalence levels of STIs among MSW were significantly higher than the broader MSM population. Co-infection of HIV and STIs were prevalent among Chinese MSM. Integration of HIV and STIs healthcare and surveillance systems is essential in providing effective HIV/STIs preventive measures and treatments. Trial Registration: PROSPERO No: CRD42013003721 [ABSTRACT FROM AUTHOR]

Background: Thirty-four countries worldwide have abnormally high sex ratios (>102 men per 100 women), resulting in over 100 million missing women. Widespread sex selective abortion, neglect of young girls leading to premature mortality, and gendered migration have contributed to these persistent and increasing distortions. Abnormally high adult sex ratios in communities may drive sexually transmitted disease (STD) spread where women are missing and men cannot find stable partners. We systematically reviewed evidence on the association between high community sex ratios and individual sexual behaviors. Methods and Findings: Seven databases (PubMed, Web of Science, Embase, Scopus, The Cochrane Database of Systematic Reviews, Sociological Abstracts, and PopLINE) were searched without restrictions on time or location. We followed PRISMA guidelines and evaluated quality according to STROBE criteria. 1093 citations were identified and six studies describing 57,054 individuals were included for review. All six studies showed an association between high community sex ratios and individual sexual risk behaviors. In high sex ratio communities, women were more likely to have multiple sex partners and men were more likely to delay first sexual intercourse and purchase sex. Only two studies included STD outcomes. Conclusions: High community sex ratios were associated with increased individual sexual risk behavior among both men and women. However, none of the studies examined unprotected sex or appropriately adjusted for gendered migration. Further studies are needed to understand the effect of community sex ratios on sexual health and to inform comprehensive STD control interventions. [ABSTRACT FROM AUTHOR]

Background: Female sex workers have been the target of numerous sexually transmitted infection (STI) prevention strategies in China, but their male clients have attracted considerably less public health attention and resources. We sought to systematically assess the prevalence of HIV, syphilis, gonorrhea, and chlamydia among heterosexual male clients of female sex workers in China. Methods/Principal Findings: Original research manuscripts were identified by searching Chinese and English language databases, and 37 studies analyzing 26,552 male clients were included in the review. Client STI prevalence across studies was heterogeneous. Pooled prevalence estimates and 95% confidence intervals were 0.68% (0.36–1.28%) for HIV, 2.91% (2.17–3.89%) for syphilis, 2.16% (1.46–3.17%) for gonorrhea, and 8.01% (4.94–12.72%) for chlamydia. Conclusions/Significance: The pooled prevalence estimates of HIV, syphilis, gonorrhea, and chlamydia among clients in this review exceed the prevalences previously reported among population-representative samples and low-risk groups in China. However, heterogeneity across studies and sampling limitations prevent definitive conclusions about how the prevalence of STIs in this population compares to the general population. These findings suggest a need for greater attention to clients’ sexual risk and disease prevalence in China’s STI research agenda in order to inform effective prevention policies. [ABSTRACT FROM AUTHOR]

In China, injection drug use is a major transmission route for HIV and hepatitis C virus (HCV) infection. Timely HIV and HCV testing among drug users is vital to earlier diagnosis, linkage to care, and retention. This study aimed to examine HIV and hepatitis C virus (HCV) testing delays at methadone clinics in Guangdong Province, China, and identify individual-level and clinic-level factors associated with delayed testing. Data from 13,270 individuals at 45 methadone clinics in Guangdong were abstracted from a national web-based surveillance database. A two-level binomial logit model was used to examine the association between individual- and clinic-level factors and delayed HIV and HCV testing, defined as receiving a test seven or more days after initial entry into the methadone system. Among 10,046 patients tested for HIV, 1882 (18.7%) had delayed testing; among 10,404 patients tested for HCV, 1542 (14.8%) had delayed testing. Among delayed testers, the median time to HCV testing was significantly longer than the median time to HIV testing (73 vs. 54 days, p<0.05). In the multivariate analysis, the likelihood of delayed HIV testing was higher among individuals with high school or greater education (adjusted odds ratio [aOR] 1.32, 95% confidence interval [CI] 1.02–1.72) and individuals enrolled at clinics with more patients (aOR 1.41, 95% CI 1.05–1.91, for each increase in 100). The likelihood of delayed HCV testing was higher among women (aOR 1.51, 95% CI 1.11–2.06) and employed individuals (aOR 1.21, 95% CI 1.02–1.43). Delayed testing for HIV and HCV is common among patients at methadone clinics in Guangdong, with many patients experiencing delays of two or more months. Structural interventions are needed to expedite testing once individuals enter the methadone maintenance program. [ABSTRACT FROM AUTHOR]