Commercial sex and risk of HIV, syphilis, and herpes simplex virus-2 among men who have sex with men in six Chinese cities

HIV Incidence and Transactional Sex Among Men Who Have Sex With Men in Ningbo, China: Prospective Cohort Study Using a WeChat-Based Platform

Background

Sexual transmission among men who have sex with men (MSM) has become the major HIV transmission route. However, limited research has been conducted to investigate the association between transactional sex (TS) and HIV incidence in China.

Objective

This study aims to investigate HIV incidence and distinguish sociodemographic and sexual behavioral risk factors associated with HIV incidence among MSM who engage in TS (MSM-TS) in China.

Methods

We conducted a prospective cohort study using a WeChat-based platform to evaluate HIV incidence among Chinese MSM, including MSM-TS in Ningbo, recruited from July 2019 until June 2022. At each visit, participants completed a questionnaire and scheduled an appointment for HIV counseling and testing on the WeChat-based platform before undergoing offline HIV tests. HIV incidence density was calculated as the number of HIV seroconversions divided by person-years (PYs) of follow-up, and univariate and multivariate Cox proportional hazards regression was conducted to identify factors associated with HIV incidence.

Results

A total of 932 participants contributed 630.9 PYs of follow-up, and 25 HIV seroconversions were observed during the study period, resulting in an estimated HIV incidence of 4.0 (95% CI 2.7-5.8) per 100 PYs. The HIV incidence among MSM-TS was 18.4 (95% CI 8.7-34.7) per 100 PYs, which was significantly higher than the incidence of 3.2 (95% CI 2.1-5.0) per 100 PYs among MSM who do not engage in TS. After adjusting for sociodemographic characteristics, factors associated with HIV acquisition were MSM-TS (adjusted hazard ratio [aHR] 3.93, 95% CI 1.29-11.93), having unprotected sex with men (aHR 10.35, 95% CI 2.25-47.69), and having multiple male sex partners (aHR 3.43, 95% CI 1.22-9.64) in the past 6 months.

Conclusions

This study found a high incidence of HIV among MSM-TS in Ningbo, China. The risk factors associated with HIV incidence include TS, having unprotected sex with men, and having multiple male sex partners. These findings emphasize the need for developing targeted interventions and providing comprehensive medical care, HIV testing, and preexposure prophylaxis for MSM, particularly those who engage in TS.

Pre-exposure prophylaxis uptake for high-risk men who have sex with men in China: a multi-city cross-sectional survey

BACKGROUND

Pre-exposure prophylaxis (PrEP) is a proven biomedical strategy to prevent HIV transmission among men who have sex with men (MSM). Despite oral PrEP is safe and effective in MSM, the use of PrEP has been discouraging, especially in high-risk MSM. And there are no relevant studies showing the use of PrEP in high-risk MSM. The purpose of this study was to get the rate of PrEP use and the factors influencing PrEP use among high-risk MSM.

METHODS

A cross-sectional study was conducted through an electronic questionnaire on the "i guardian Platform", and "snowballing" method was used to recruit MSM in six cities in China, including Beijing, Shenzhen, Chengdu, Changsha, Jinan and Nanjing in China, from January to April 2021. Univariate and multivariate logistic regression analysis were used to analyze the factors associated with the use of PrEP among high-risk MSM who had heard about PrEP.

RESULTS

Among the 1865 high-risk MSM who had heard of PrEP, the rates of those who were willing to use PrEP, had knowledge awareness of PrEP, and had used PrEP were 96.7%, 24.7%, and 22.4%, respectively. Multivariate logistic regression analysis of PrEP use in high-risk MSM showed that more PrEP was used by those who were 26 years or older (OR = 1.86, 95%CI 1.17 ~ 2.99), had master degree or above (OR = 2.37, 95% CI 1.21 ~ 4.72), had unstable work (OR = 1.86, 95% CI 1.16 ~ 2.96), had tested five or more HIV times in the past year (OR = 3.09, 95% CI 1.65 ~ 6.04), had consulted PrEP (OR = 22.05, 95% CI 14.87 ~ 33.91) and had PrEP knowledge awareness (OR = 1.90, 95% CI 1.41 ~ 2.55) (P < 0.05).

CONCLUSIONS

The rate of PrEP use in high-risk MSM was relatively low. PrEP was used more by high-risk MSM with unstable jobs, higher education, frequent HIV testing, and PrEP counseling. Public education on PrEP for MSM should continue to be enhanced to help them use PrEP in a timely and accurate manner.

Prevalence of HIV and syphilis and their co-infection among men having sex with men in Asia: A systematic review and meta-analysis

Background

Studies found that the group of men who have sex with men (MSM) is at a very high level of risk of HIV and sexually transmitted infections (STIs) in Asian regions due to multiple reasons. Although the prevalence of HIV among general people in Asia is considered low, the prevalence of HIV and Syphilis among MSM in this region was found very high and usually, it goes unnoticed. This study aimed to inspect the prevalence of and trends in HIV, Syphilis, and their co-infection among MSM in Asia.

Methods

A systematic search was performed on January 5, 2021, in PubMed, Web of Science, and Google Scholar databases. To evaluate the heterogeneity, Q-tests, and I ² were used. To explore the publication bias, Eggers' test and funnel plot were used. The random-effect model and subgroup analysis were performed due to the significant heterogeneity.

Results

A total of 2872 articles were identified, and 66 articles were included in the final analysis. The overall prevalence of HIV and Syphilis among MSM was estimated considering 69 estimates from 66 studies whereas 19 estimates of co-infection were found in 17 studies. The pooled HIV prevalence was 8.48% (CI: 7.01-9.95) and the pooled Syphilis prevalence was 9.86% (CI: 8.30-11.41) with significant heterogeneity and publication bias. The pooled prevalence of HIV and Syphilis co-infection was 2.99% (CI: 1.70-4.27) with significant heterogeneity and no publication bias. The HIV, Syphilis, and HIV-Syphilis co-infection prevalence estimates exhibited an upward trend during 2002-2017.

Conclusions

HIV, Syphilis, and their co-infection are quite prevalent among MSM in the Asia-Pacific region. Integrated and intensified intervention strategies, HIV testing, and improved access to antiretroviral treatment as well as increased awareness are needed to reduce HIV, Syphilis, and their co-infection among the discussed vulnerable group.

Prevalence and associated factors of sexually transmitted infections among methamphetamine users in Eastern China: a cross-sectional study

BACKGROUND

The reported incidence of sexually transmitted infections (STIs) in China has been increasing over the last decades, especially among drug users, which has become one of the main burdens of public health in China. This study was conducted to estimate the prevalence and associated factors of STIs among non-injecting methamphetamine (MA) users in Eastern China.

METHODS

A cross-sectional survey was conducted among 632 MA users in Eastern China in 2017. Demographic characteristics, sexual behaviors, behaviors of MA use and sexual health knowledge were collected through questionnaire. First pass urine specimens were collected and detected for deoxyribonucleic acid (DNA) of Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) with Nucleic Acid Amplification Technology (NAAT), while blood specimens were collected and detected for antibodies of Human immunodeficiency virus (HIV), Herpes simplex virus type-2 (HSV-2), and syphilis with enzyme-linked immune sorbent assay (ELISA).

RESULTS

Among the 632 MA users, 464 (73.42%) were males, 60.92% were < 35 years of age, 546 (86.39%) were Shandong residents. 317 (50.16%, 95% CI 46.26-54.06%) participants were tested positive for at least one kind of STIs, including 242 (38.29%, 95% CI 34.50-42.08%) for HSV-2, 107 (16.93%, 95% CI 14.01-19.85%) for active syphilis, 46 (7.28%, 95% CI 5.25-9.31%) for treated syphilis, 40 (6.33%, 95% CI 4.43-8.23%) for CT, 6 (0.95%, 95% CI 0.19-1.71%) for HIV, and 3 (0.47%, 95% CI 0.06-1.00%) for NG infection. 99 (15.66%, 95% CI 12.83-18.49%) participants were co-infected with two kinds of STIs, including 91 (14.40%, 95% CI 11.66-17.14%) participants were co-infected with HSV-2 and syphilis. 14 (2.22%, 95% CI 1.07-3.37%) participants were co-infected with three kinds of STIs, and 4 HIV positive participants were co-infected with both syphilis and HSV-2. In the multiple logistic regression analysis, the results showed that females (adjusted OR [AOR] = 7.30, 95% CI 4.34-12.30) and individuals ≥ 35 years of age (AOR = 2.97, 95% CI 2.04-4.32) were more likely to test positive for STIs among MA users, whereas participants who acquired sexual health knowledge primarily from the Internet (AOR = 0.57, 95% CI 0.40-0.82) and those whose regular partners did not use drugs (AOR = 0.59, 95% CI 0.37-0.94) were less likely.

CONCLUSIONS

This study found that the prevalence of HSV-2 and syphilis are alarming high among non-injecting MA users in Shandong Province in Eastern China. The prevention and control intervention of STIs among MA users in Shandong were needed, especially on females and MA users ≥ 35 years of age.

Trends of HIV/Syphilis/HSV-2 seropositive rate and factors associated with HSV-2 infection in men who have sex with men in Shenzhen, China: A retrospective study

Objectives

To analyze the trends of HIV/syphilis/HSV-2 seropositive rate and explore the related factors with HSV-2 infection to provide the basis for adjusting STD intervention strategies and formulating prevention and control measures among MSM in Shenzhen.

Methods

Time-location sampling was conducted among MSM in Shenzhen in 2012, 2014, 2016, and 2018. Data on demographics, sexual behaviors and the laboratory test results of HIV, syphilis, HSV-2 were collected. The χ² trend test was used to analyze the trends of HIV/syphilis/HSV-2 seropositive rate. The binary logistic regression model was used to explore the factors associated with HSV-2 infection.

Results

The seropositive rate of HIV fell significantly from 15.9% in 2012 to 8.7% in 2018 (P_trend = 0.003), syphilis seropositive rate was significantly decreased from 20.4% in 2012 to 14.8% in 2018 (P_trend = 0.025), HSV-2 seropositive rate had no significant change (16.7% in 2012 to 14.0% in 2018; P_trend = 0.617). In principal component logistic regression analysis showed that FAC1_1 (X₁ = Ever had sex with female, X₂ = Gender of first sexual partner, X₃ = Marital status, X₄ = Age group), FAC2_1 (X₅ = Education, X₆ = Monthly income (RMB), X₇ = Frequency of condom use in anal sex with men in the past 6 months), and FAC4_1 (X₉ = History of STDs) were significantly associated with HSV-2 infection.

Conclusions

The seropositive rates of HIV and syphilis have dropped significantly but are still high. HSV-2 seropositive rate had no significant change and maintained a high level. It is necessary to continue strengthening HIV and syphilis interventions among MSM in Shenzhen. HSV-2 detection and intervention are urgently required for MSM, which might be another effective biological strategy further to control the HIV epidemic among MSM in Shenzhen.

Clinical and laboratory impact of concomitant syphilis infection during acute HIV

INTRODUCTION

Cognitive impairment has been reported in people living with HIV-1 (PLWH) with prior syphilis, while PLWH who present with incident syphilis have reduced blood CD4 T-lymphocyte and elevated HIV-1 RNA levels. However, the clinical, virological and neurocognitive effects of syphilis during acute HIV-1 (AHI) remain unknown.

METHODS

Pre-antiretroviral therapy laboratory outcomes and neurocognitive performance in a four-test battery in the SEARCH10/RV254 AHI cohort were compared according to syphilis status, determined by serum Treponema pallidum haemagglutination (TPHA), Venereal Disease Research Laboratory (VDRL) and syphilis treatment history. Impaired cognitive performance was defined as having z-scores ≤ -1 in at least two tests or ≤ -2 in at least one test.

RESULTS

Out of 595 AHI participants (97% male, median age of 26 years and estimated duration of HIV-1 infection of 19 days), 119 (20%) had history of syphilis (TPHA-positive), of whom 51 (9%) had untreated syphilis (TPHA-positive/VDRL-positive/without prior treatment). Compared with those without syphilis (TPHA-negative), individuals with untreated syphilis had higher CD8 T-lymphocyte levels but not higher plasma HIV-1 RNA or lower CD4 T-lymphocyte levels. Taking into account estimated duration of HIV-1 infection (P < 0.001), and later Fiebig stages (III-V) (P < 0.001), those with untreated syphilis had higher CD8 T-lymphocyte levels (P = 0.049). Individuals with any syphilis (TPHA-positive), but not untreated syphilis, had higher odds of impaired cognitive performance than those without (P = 0.002).

CONCLUSIONS

During AHI, individuals with any history of syphilis (TPHA-positive) had poorer cognitive performance than those without syphilis. However, syphilis was not associated with worsened HIV disease measures as described in chronic infection.

Association of nitrite inhalants use and unprotected anal intercourse and HIV/syphilis infection among MSM in China: a systematic review and meta-analysis

Background

Nitrite inhalant use is very common among men who have sex with men (MSM) in China. However, there is lack of national representative data on use among Chinese MSM, and the mechanism of how nitrite inhalant use impacts HIV infection in MSM is unclear. This meta-analysis aims to understand the characteristics of Chinese MSM nitrite inhalant users and to determine the associations between nitrite inhalant use and sexual behaviors, the prevalence of HIV, and the prevalence of syphilis.

Methods

We searched PubMed, Web of Science, Chinese National Knowledge Infrastructure, Chinese Wanfang Data, and VIP Chinese Journal Database for relevant literature published from January 1985 to December 2017.

Results

Fifteen eligible studies, with a total of 18,981 Chinese MSM participants, were included. Compared with nitrite inhalant nonusers, users were more likely to be younger, have a higher level of education, and seek sexual partners using the Internet. Nitrite inhalant users were more likely to engage in high-risk sexual behaviors, including condomless anal intercourse (odds ratio [OR] = 1.33), group sex (OR = 2.26), and commercial intercourse (OR = 1.50). Nitrite inhalants users had a higher prevalence of HIV (OR = 1.83), higher prevalence of syphilis (OR = 1.38) and had higher lifetime HIV testing rates (OR = 1.33) compared with nonusers (each p < 0.05).

Conclusions

Nitrite inhalant users have higher HIV and syphilis prevalence by increasing levels of high-risk sexual behaviors. China should expand HIV testing, treatment as prevention (TasP), and Pre-exposure prophylaxis (PrEP) among MSM, especially among nitrite inhalants using MSM, to reduce their risk of HIV infection and transmission.

HIV Epidemiology and Prevention in Southwestern China: Trends from 1996-2017

The aim of this review is to describe long-term HIV epidemiology and prevention trends in Guangxi, a provincial-level region located along a major drug trafficking corridor in southwestern China. Between 1996 and 2006, HIV transmission in Guangxi was primarily fueled by Injection Drug Use (IDU). Since 2006, heterosexual sex has become the dominant mode of HIV transmission, followed by drug injection. Moreover, older, heterosexual adults appear to be at increased risk for HIV. The vast majority of new HIV cases are attributed to local HIV subtypes already circulating within Guangxi (93%), though imported subtypes are associated with younger age groups. Since 2011, HIV incidence in Guangxi has stabilized, due in part to HIV prevention efforts that include expanded HIV testing, antiretroviral treatment, and other intervention measures. Between 1996 and 2017, Guangxi, China experienced dramatic changes in the primary HIV transmission mode and at-risk age group. Due in part to local and National AIDS control and prevention campaigns, HIV incidence trends in Guangxi no longer appear to be increasing.

Gender Identity and Sexual Orientation in Chinese Men Who Have Sex with Men: A Latent Class Analysis

Men who have sex with men (MSM) are a diverse population yet are often treated as a monolithic risk group. In China, MSM have long been characterized as a "bridge population" of closeted men who are married to (or will marry) women due to sociocultural expectations. Latent class models can inform a more nuanced yet empirical characterization of this population. In total, 1424 eligible respondents recruited online provided self-reported behavioral data. Nine items related to constructs including sexual behaviors, sexual orientation, and gender identity informed the latent class model. Logistic regression was used to measure associations between latent class membership and HIV-related sexual and health-seeking behaviors. Model fit indicated a population structure made up of four classes that we characterized as "Gender nonconforming" (4.3%), "Closeted-unmarried" (29.9%), "Closeted-married" (24.6%), and "Out" (41.2%). Members of the "gender nonconforming" class were more likely to report HIV-related risk behaviors, and "Closeted-unmarried" class members were less likely to report health-seeking behaviors, both relative to "Out" members. The largest latent class was made up of members of the "Out" class, an enlightening revision of a population traditionally viewed as largely closeted men. Two types of "closeted" classes emerged, distinguished by divergent tendencies regarding marriage and health seeking. Findings suggest that current understandings of Chinese MSM are simplistic (regarding closeted behaviors) and too narrow (in its definition of MSM as cisgender men). A more nuanced understanding of MSM subgroups and their heterogeneous risk behaviors will be critical for provision of more meaningful prevention services.

Compare HIV/syphilis infections between age groups and explore associated factors of HIV/syphilis co-infections among men who have sex with men in Shenzhen, China, from 2009 to 2017

The aim of this study is to assess the HIV/syphilis epidemic among men who have sex with men (MSM) aged <50 years and ≥50 years in Shenzhen, and explore the associated factors of HIV/syphilis co-infections among MSM in Shenzhen, in order to help prevention and intervention programs determine their target sub-group. A serial cross-sectional study was conducted on MSM in Shenzhen city, China from 2009 to 2017. A questionnaire was used to collect demographic characteristics, history of HIV testing, history of blood donation and sexual behaviors. 5 ml of venous blood were collected for syphilis and HIV tests. The overall prevalence of HIV, syphilis, HIV/syphilis co-infection was 9.40%, 18.97%, and 4.91%, respectively. The prevalence of HIV (15.26%), syphilis (27.71%), HIV/syphilis co-infection (9.24%) in aged ≥50 years MSM was significantly higher than aged <50 years MSM (9.15%, 18.59% and 4.72%, respectively). The following factors were found to be significantly associated with HIV/syphilis co-infections (P<0.05): age≥50 years (OR = 1.78, 95% CI = 1.10–2.87), high school or lower (OR = 1.49, 95% CI = 1.10–2.01), monthly income ≤436.2 USD (OR = 1.74, 95% CI = 1.25–2.42), monthly income 436.4–727.2 USD (OR = 1.46, 95% CI = 1.05–2.03), ≥2 anal sex partners in the past 6 months (OR = 1.59, 95% CI = 1.02–2.49), ≥2 oral sex partners in the past 6 months (OR = 1.60, 95% CI = 1.08–2.36), inconsistent condom use during anal sex in the past 6 months (OR = 1.50, 95% CI = 1.11–2.03). We found that aged <50 years and ≥50 years MSM in Shenzhen had a high prevalence of HIV/syphilis infection in a period from 2009 to 2017. Age-specific sexually transmitted diseases education, prevention, and intervention programs for aged ≥50 years MSM should be implemented urgently and integrated interventions of both HIV and syphilis infections on MSM are needed in the future.

Using latent class analysis to identify money boys at highest risk of HIV infection

OBJECTIVES

Limited research has been conducted to investigate the characteristics of money boys (MBs) in China. This study was aimed to identify the subgroups of MBs based on sexual behaviors, Net-based venue sex-seeking, and substance abuse.

STUDY DESIGN

Cross-sectional study.

METHODS

Convenience sampling was used to recruit MBs from December 2014 to June 2015 in Tianjin, China. Face-to-face interviews were conducted for 330 MBs, and trained interviewers collected data.

RESULTS

The laboratory-confirmed human immunodeficiency virus (HIV)-positive rate was 11.52% among 330 MBs. Four classes were identified through latent class analysis (LCA) method: 'relatively safe behavior' group, 'higher sexual risk' group, 'multiple sexual-partners' group, and 'unprotected sex and substance abuse' group, and there is a significant difference based on the HIV status. Significant differences were found in original residence, monthly income, duration in sex trade, employment, history of sexually transmitted infection (STI), HIV testing, knowledge of free antiviral treatment policy, and awareness of free AIDS testing between the four latent classes (P < 0.05). MBs who used Net-based venues to seek sexual partners; who have inconsistent condom use, substance abuse, a longer duration in sex trade, multiple sexual clients, and multiple anal sex; and who were full-time employed had the highest risk of HIV infection.

CONCLUSIONS

The utility of LCA to identify subgroups based on risky behaviors attributes to formulating targeted intervention strategy.

Links between transactional sex and HIV/STI-risk and substance use among a large sample of European men who have sex with men

BACKGROUND

In Europe, the highest proportion of HIV diagnoses are in gay men and other men who have sex with men (MSM). Globally, HIV prevalence is particularly high among males who report selling sex, but rates among men who buy sex from other men are less clear. This study analyzed the association of transactional sex (TS) and HIV diagnosis, sexually transmitted infection (STI) diagnoses, and various drug use; and examined the variations in TS by payment direction.

METHODS

We conducted a cross-sectional, non-randomized, observational study. This European MSM Internet Survey recruited MSM from 38 European countries. For descriptive purposes we stratified according to TS behavior (frequently selling sex, frequently buying sex, neither frequently selling nor buying sex in the previous 12 months), and we constructed separate multivariable logistic regression models to investigate whether engaging in TS accounted for some of the HIV- and STI diagnoses and drug use in this population.

RESULTS

Of almost 161,000 sexually active MSM, 12.2% engaged in TS. The multivariable logistic regression results showed that relative to not frequently engaging in TS, frequently selling sex was independently associated with a higher odds of reporting diagnosed HIV (ever, adjusted odds ratio [aOR] 1.60, confidence interval [CI] 95% 1.39 to 1.85), bacterial STIs (past 12 months, aOR 1.75 CI 95% 1.54 to 2.00), using heroin or crack cocaine or injecting drugs (aOR 3.17, CI 95% 2.70 to 3.73), and using benzodiazepines (aOR 2.13, CI 95% 1.88 to 2.41). Compared to men not engaging in frequent TS, frequently buying sex was associated with a higher odds of using benzodiazepines (aOR 2.13, CI 95% 1.88 to 2.41).

CONCLUSIONS

MSM who frequently sell sex suffer greater sexual- and substance use risks than other MSM, but both men who frequently sell and those who buy sex are more likely to use benzodiazepines. MSM who sell sex to other men constitute an important at-risk population who must be offered targeted health services.

Syphilis associated with recreational drug use, depression and high-risk sexual behaviour in men who have sex with men: a case-control study in China

OBJECTIVE

We investigated syphilis prevalence among men who have sex with men (MSM) in China, as well as potential risk factors. Our principal hypothesis was that syphilis would be associated with the use of recreational drugs such as methamphetamines.

METHODS

From April to October 2013, we used several methods to recruit MSM in Qingdao, collecting demographic/behavioural information via self-administrated questionnaires. Trained health workers collected blood for the Treponema pallidum particle assay (TPPA) with positives confirmed by a toluidine red unheated serum test. We used an unmatched case-control study to identify factors that might predict syphilis infection using multivariable logistic regression.

RESULTS

We recruited 447 MSM who agreed to participate and who completed syphilis testing. Of 71 (15.9%) syphilis-positive MSM, 44 (62.0%) used drugs. Of 376 (84.1%) syphilis-negative MSM, 186 (49.5%) used drugs. We found a positive association with syphilis for any recreational drug use (crude OR (cOR) 1.7, 95 % CI 1.0 to 2.8), frequent methamphetamine use (cOR 2.4, 95% CI 1.1 to 5.3) and multiple drug use (adjusted OR (aOR) 3.4, 95% CI 1.3 to 9.2). Syphilis-positive men were more likely to have a higher physical depression score (aOR 5.2, 95% CI 1.1 to 24.4), be > 30 years old (aOR 2.7, 95% CI 1.5 to 4.8), report a prior STI (aOR 4.1, 95% CI 2.3 to 7.3) and report a sex party experience (aOR 2.2, 95% CI 1.1 to 4.4).

CONCLUSIONS

Recreational drug use, depression and high-risk sexual behaviours were associated with syphilis infection among MSM in China. Only a multifaceted approach is likely be effective in control of both syphilis and HIV .

Subsequent Sexual Risks Among Men Who Have Sex with Men May Differ by Sex of First Partner and Age at Sexual Debut: A Cross-Sectional Study in Beijing, China

Sexual debut experience may influence HIV/sexual risks among men who have sex with men (MSM). We assessed associations between age of sexual debut and sex of debut partner with recent (past-3-month) sexual/HIV/syphilis risks among 3588 community-based Chinese MSM. Sexual debut with women was associated with more recent (condomless) insertive anal sex with men, more recent (condomless) vaginal sex, and more lifetime female partners. Sexual debut with men was associated with more recent (condomless) receptive anal sex with men and more lifetime male partners. All associations were strongest among those having first sex ≤18 years in both groups. Earlier sexual debut was associated with higher HIV/syphilis risk; HIV risk was higher with first sex with a man, but syphilis was higher with first sex with a woman. Earlier age of sexual debut is associated with greater HIV/syphilis and sexual risks, but MSM risk differs with first sex with women versus men.