Sexually Transmitted Infections among Heterosexual Male Clients of Female Sex Workers in China: A Systematic Review and Meta-Analysis Megan M. McLaughlin 1 *, Eric P. F. Chow 2 , Cheng Wang 3 , Li-Gang Yang 3 , Bin Yang 3 , Jennifer Z. Huang 4 , Yanjie Wang 2 , Lei Zhang 2 *, Joseph D. Tucker 1,3 1 UNC Project – China, Guangzhou, China, 2 The Kirby Institute, University of New South Wales, Sydney, Australia, 3 Guangdong Provincial Center for STI & Skin Diseases Control, Guangzhou, China, 4 Department of International Health, School of Nursing and Health Studies, Georgetown University, Washington, District of Columbia, United States of America Abstract 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. Citation: McLaughlin MM, Chow EPF, Wang C, Yang L-G, Yang B, et al. (2013) Sexually Transmitted Infections among Heterosexual Male Clients of Female Sex Workers in China: A Systematic Review and Meta-Analysis. PLoS ONE 8(8): e71394. doi:10.1371/journal.pone.0071394 Editor: Sten H. Vermund, Vanderbilt University, United States of America Received June 22, 2012; Accepted June 29, 2013; Published August 12, 2013 Copyright: ß 2013 McLaughlin et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: Support for this research came from an National Institutes of Health (NIH) Fogarty K01 Award (US NIH 1K01TW008200-270 01A1), the UNC Fogarty AIDS International Research and Training Program (NIH FIC D43 TW01039), the UNC Social Science Research on HIV/AIDS in China (NIH NICHD R24 HD056670-01), the UNC Center for AIDS Research, and the Harvard Institute for Global Health. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. * E-mail: mclaughlin.megan@gmail.com (MMM); lzhang@kirby.unsw.edu.au (LZ) Introduction China has a history of both large epidemics of sexually transmitted infections (STIs) and comprehensive population-based responses. In the 1950s, the Chinese government launched a massive campaign to eliminate STIs through screening, free penicillin, and suppression of the commercial sex industry [1,2]. Although there were limited epidemiological investigations, by the 1960s STIs were thought to be extremely uncommon [2]. In the wake of extensive economic and social change since the 1980s, both commercial sex and STIs have experienced a marked resurgence in China [3]. The rising prevalence of syphilis and other STIs in the general population in China suggests the potential for the HIV epidemic in China to accelerate through sexual transmission [3–9]. Heterosexual transmission has emerged in recent years as the primary mode of HIV transmission in China, accounting for 62.6% of estimated new infections in 2009, compared to 11.3% prior to 2006 [10–12]. Subgroups of heterosexual men in China are likely at an increased risk for STIs and HIV infection. One male heterosexual risk group in China that has attracted concern is ‘‘mobile men with money’’–wealthy businessmen and officials who purchase unprotected sex [13]. Another male heterosexual group believed to be at increased risk of STIs are ‘‘surplus men’’–an increasing population of young, poor, unmarried men, resulting from China’s imbalanced sex ratio [14]. This group of men may be unable to afford a bride price but able to pay the price of a low-fee sex worker [14]. Understanding these and other subgroups of heterosexual Chinese men who purchase sex is important for designing effective STI/HIV prevention strategies. China’s national median prevalence of commercial sex purchased by men is 4.2% (95% confidence interval [CI], 3.5%–5.2%), exceeding the median prevalence of 2.4% among 55 other countries [15]. The existence of both a significant amount of data on the health and behavior of male clients and population-based PLOS ONE | www.plosone.org 1 August 2013 | Volume 8 | Issue 8 | e71394