Wang et al. BMC Public Health 2011, 11:955 http://www.biomedcentral.com/1471-2458/11/955 STDs, which facilitate the transmission of HIV infection [4,5]. Reported epidemiological studies showed varied STD/ HIV prevalence among STD clinic attendees in China, with HIV ranging from 0% to 12.6%, Chlamydia tracho- matis from 6.3% to 30.3%, gonorrhea from 4.1% to 17.3% and syphilis from 9.1% to 23.2% [6-13]. None of these studies pertained to using identical laboratory methods to evaluate STDs in different areas in China. The differ- ences in prevalence may result from varying sampling strategies and diagnostic capabilities, but also very likely reflect local endemic conditions in different geographic areas. Further understanding of STD/HIV infection pre- valence in different regions in China through use of iden- tical sampling and laboratory methods is necessary for proper planning and implementation of STD/HIV con- trol strategies. The first acquired immunodeficiency syndrome (AIDS) case in China was reported in June 1985 [14]. The epi- demic has now entered a wide spreading phase [15,16]. Historically, the majority of reported HIV infections in China were acquired through injection drug use and use of commercial blood/plasma products. Sexually trans- mitted HIV cases have steadily increased and comprised more than half the reported HIV/AIDS infections since 2007 [17,18]. Heterosexual transmission of HIV accounted for 47.1% of the reported HIV cases in 2009 while homo- sexual transmission of HIV accounted for 8.6% of those cases. In 2009, as many as 57% of HIV-infected adults in China were estimated to be unaware of their HIV serosta- tus. “To little, too late” is the current HIV testing status in China. Although the Chinese government has initiated a widespread mass-screening program to enhance case find- ing, this program is not linked to any existing system of clinical care [19]. Client-initiated voluntary counseling and testing (VCT) has been effective in identifying substantial numbers of HIV-positive individuals. However, screening coverage remains low for many reasons including low per- ception of personal HIV risk, fear of stigma, and discrimi- nation [20]. Routine opt-out provider-initiated HIV testing and counseling (PITC) services has been recommended as a newer approach to increase knowledge of HIV status. In routine opt-out PITC, HIV testing and counseling are recommended as standard components of medical care at healthcare facilities. One worldwide barrier to HIV testing has been stigma, an issue that has been increasingly acknowledged in the Chinese response to HIV. The term “opt-out” means that patients must explicitly refuse an HIV test. In this way, PITC can help to overcome stigma and to increasingly enable patients to rapidly know their HIV status. In settings where high-risk patients await health care services, such as STD clinics, failure to imple- ment PITC is a missed opportunity for patients to benefit Page 2 of 8 from counseling, prevention, early diagnosis, and referral into care and treatment for HIV infection. Currently, there are debates on whether PITC is needed among STD clinics in China. Moreover, the acceptance of PITC by both providers and patients remains unknown. This aim of this study was to investigate STD patterns and HIV prevalence among STD clinic attendees in dif- ferent areas in China and their associated risk factors. The feasibility of PITC was evaluated as well. Methods Participants A cross-sectional study was conducted among STD clinic attendees in 46 STD clinics from 8 cities distributed in 4 provinces, including the Jiangsu, Guangdong, Hainan and Guangxi provinces of China. The 46 clinics were major medical institutions providing STD services in these cities. Nearly all of those clinics were public and located in urban areas. The outpatient loads in these clinics accounted for more than 75% of the total outpatient vis- its in these cities. Between July 2009 and September 2010, potential participants were identified at the STD clinics in the Guangxi, Jiangsu, and Hainan provinces. Participant identification in the Guangdong province was initiated 3 weeks later due to logistical reasons. Only those attendees who met the following criteria were included in the study: age ≥ 18 years, male gender, and either: presentation with STD related complaints, history of high-risk sexual behaviors (such as exchange sexual activity or multiple sexual partners), or history of one or more sexual partners with a STD. Patients seeing physi- cians for sexual dysfunction or for skin diseases unrelated to STDs were excluded. To ensure privacy, the interviews were conducted in a separate space within the clinic. Interviewers were trained in techniques for conducting research in the sensitive topics of sexual health. Regular meetings were held to discuss the progress of the survey as well as any special problems encountered. The pur- pose and procedures of the study were explained to each study participant Participants who were willing and able to complete the questionnaire by themselves were given written questionnaires to complete themselves. In such cases, interviewers were available to help with answering participants’ questions if needed. After completing the questionnaire, the participants were provided with information about HIV and other STD testing, and subsequently were asked to undergo HIV and STD testing. Participants were informed of the syphilis test results and the HIV test results (if negative) by the next day. Results of confirmatory HIV tests, Neis- seria gonorrhoeae tests, and Chlamydia trachomatis tests were provided 10 days later. If necessary, treatment of individual STDs was initiated on the same day that results were disclosed. After-HIV-testing, counseling