Factors Associated with Inconsistent Condom Use among Men Who Have Sex with Men in Cambodia

Background

Compared to the general population, men who have sex with men (MSM) are at greater risk for HIV and less understood due to their more hidden and stigmatized nature. Moreover, the discrepancy in findings in the literature merits further investigations in MSM populations from different cultures and settings. We therefore conducted this study to explore factors associated with inconsistent condom use among high-risk MSM in Cambodia.

Methods

This cross-sectional study was conducted in 2014 among 367 MSM randomly selected from Battembang and Siem Reap using a two-stage cluster sampling method. A structured questionnaire was used for face-to-face interviews to collect information on characteristics of respondents, HIV testing history, self-perception of HIV risk, substance use, sexual behaviors, mental disorders, and HIV knowledge. Multivariable logistic regression analysis was performed to identify factors independently associated with inconsistent condom use.

Results

On average, 62.3% of respondents reported that they always used condoms over the past three months. The rates varied with types of sexual partners; the proportion of respondents who reported always using condoms was 55.1%, 64.2%, 75.9%, 73.0%, 78.1%, and 70.3%, for sexual partners who were girlfriends, boyfriends, female sex workers, male sex workers, female clients, or male clients, respectively. After adjustment, inconsistent condom use was significantly associated with age of ≥25 (AOR = 1.77, 95% CI = 1.09–2.86), self-rated quality of life as good or very good (AOR = 4.37, 95% CI = 1.79–5.67), self-perception of higher HIV risk compared to the general population (AOR = 2.37, 95% CI = 1.35–4.17), illicit drug use in the past three months (AOR = 5.76, 95% CI = 1.65–10.09), and reported consistent lubricant use when selling anal sex to men in the past three months (AOR = 2.85, 95% CI = 1.07–8.12).

Conclusions

We found risky sexual behaviors to be considerably high among MSM in this study, especially among those who used illicit drugs or were older than 25. HIV education and social marketing should be expanded and specifically designed for MSM to better educate on the increased risk of HIV with unprotected anal sex and illicit drug use as risk factors, and the importance of the use of both condoms and lubricant during anal intercourse.     

Risk Factors for HIV and Unprotected Anal Intercourse among Men Who Have Sex with Men (MSM) in Almaty, Kazakhstan

Introduction

Men who have sex with men (MSM) are at high risk for HIV infection. MSM in Central Asia, however, are not adequately studied to assess their risk of HIV transmission. Methods: This study used respondent driven sampling methods to recruit 400 MSM in Almaty, the largest city in Kazakhstan, into a cross-sectional study. Participation involved a one-time interviewer-administered questionnaire and rapid HIV screening test. Prevalence data were adjusted for respondent network size and recruitment patterns. Multivariate logistic regression was used to investigate the association between HIV and selected risk factors, and unprotected anal intercourse (UAI) and selected risk factors.

Results

After respondent driven sampling (RDS) weighted analysis, 20.2% of MSM were HIV-positive, and 69.0% had unprotected sex with at least one male partner in the last 12 months. Regression analysis showed that HIV infection was associated with unprotected receptive anal sex (AOR: 2.00; 95% CI: 1.04–3.84). Having unprotected anal intercourse with male partners, a measure of HIV risk behaviors, was associated with being single (AOR: 0.38; 95% CI: 0.23–0.64); very difficult access to lubricants (AOR: 11.08; 95% CI: 4.93–24.91); STI symptoms (AOR: 3.45; 95% CI: 1.42–8.40); transactional sex (AOR: 3.21; 95% CI: 1.66–6.22); and non-injection drug use (AOR: 3.10; 95% CI: 1.51–6.36).

Conclusions

This study found a high HIV prevalence among MSM in Almaty, and a population of MSM engaging in multiple high-risk behavior in Almaty. Greater access to HIV education and prevention interventions is needed to limit the HIV epidemic among MSM in Almaty.     

Factors Associated with Low Levels of HIV Testing among Men Who Have Sex with Men (MSM) in Brazil

The aim of this study was to assess risk factors associated with low levels of HIV testing among MSM recruited through respondent driven sampling (RDS) in Brazil. Of 3,617 participants, 48.4% had never tested previously for HIV. A logistic model indicated that younger age, lower socioeconomic class, education, poor HIV/AIDS knowledge, no history of cruising, and having been tested during the study were characteristics independently associated with low levels of previous HIV testing. The HIV testing rate among MSM in Brazil is still low in spite of the availability of a large number services providing universal and free access to HIV/AIDS diagnosis and treatment. To respond to low utilization, the authors propose a higher priority for testing for key populations such as MSM, expanded education, expanding testing sites and a welcoming and nonjudgmental environment in health services.     

Factors Associated with Unprotected Anal Intercourse among Men Who Have Sex with Men in Liaoning Province,China

Background

HIV prevalence among men who have sex with men (MSM) has increased rapidly. MSM may play a bridging role in the spread of HIV and other STDs from the high-risk population to the general population. Interventions to reduce high-risk behavior are the key to controlling the spreading of HIV in the MSM population and the primary strategy for reducing the spread of AIDS in China. The purpose of the study was to examine the demographic characteristics of MSM, evaluate the HIV-related knowledge of MSM, and identify factors associated with unprotected anal intercourse (UAI) among MSM to make recommendations for future research.

Methodology/Principal Finding

A cross-sectional survey was conducted among 293 MSM in Fushun and Huludao City, China. A total of 91 participants (34.0%) reported engagement in UAI with a male partner during the previous six months. The results of univariate analysis showed that UAI was associated with older age, lower levels of education, less knowledge about HIV, and not receiving condoms, lubricant, peer education, AIDS counseling, STD checks, and informational materials (p<0.05). In a multivariate logistic regression model, awareness of the major HIV transmission routes (OR = 2.191; 95% CI: 0.869 to 5.524), receiving condoms (OR = 2.164; 95% CI: 1.149 to 4.076), receiving peer education (OR = 2.632; 95% CI: 1.566 to 4.426), and AIDS counseling (OR = 2.347; 95% CI: 1.260 to 4.372) were independently associated with a lower risk of UAI.

Conclusions/Significance

The study suggested that UAI could be decreased by improving education about AIDS, increasing the promotion of voluntary counseling and testing (VCT), and improving the accessibility and convenience of service.     

Prevalence of HIV Infection and Associated Risk Factors among Men Who Have Sex with Men (MSM) in Harbin,P. R. China

Objective

To assess the prevalence of HIV infection and characteristically risk of factors which associated with HIV infection among MSM in Harbin, China.

Methods

A face-to-face questionnaire interview was conducted among 463 Men Who Have Sex with Men (MSM) who were recruited by the snowball sampling in Harbin from April, 2011 to July, 2011. The questionnaire mainly included demographics, AIDS knowledge, homosexual behavior and the status of intervention in MSM. Blood specimens were obtained and tested for the diagnoses of HIV, syphilis and hepatitis C virus (HCV). Associations between above exposed factors and HIV infection were analyzed using a univariate analysis and forward stepwise logistic regression.

Results

The prevalence of HIV and syphilis was 9.5 and 14.3%. The awareness rate of AIDS was 86.8%. The rate of unprotected sexual behavior was 57.6% of MSM during the past 6 months. The univariate analysis identified that the age (age≥35 years old), cohabitation, more than 10 years of homosexual behavior and more than 10 homosexual partners were risk factors which associated with the HIV infection, and that protected sex during the past 6 months was a protective factor for the HIV infection. The multivariate analysis identified that the duration of homosexual behavior and commercial sexual behavior were independent risk factors which associated with the HIV infection, and the protected sex during the past 6 months was a protective factor for the HIV infection.

Conclusion

The prevalence of HIV among MSM in Harbin has been rapidly increasing in the past few years. Targeted, tailored, and comprehensive interventions are urgently needed to prevent the HIV infection from MSM.     

HIV Transmission among Men Who Have Sex with Men due to Condom Failure

Background

Despite preventive efforts, HIV incidence remains high among men who have sex with men (MSM) in industrialized countries. Condoms are an important element in prevention but, given the high frequency of condom use and their imperfect effectiveness, a substantial number and proportion of HIV transmissions may occur despite condoms. We developed a model to examine this hypothesis.

Methods

We used estimates of annual prevalent and incident HIV infections for MSM in Ontario. For HIV-negative men, we applied frequencies of sexual episodes and per-contact HIV transmission risks of receptive and insertive anal sex with and without a condom and oral sex without a condom. We factored in the proportion of HIV-infected partners receiving antiretroviral therapy and its impact in reducing transmissibility. We used Monte-Carlo simulation to determine the plausible range for the proportion of HIV transmissions for each sexual practice.

Results

Among Ontario MSM in 2009, an estimated 92,963 HIV-negative men had 1,184,343 episodes of anal sex with a condom and 117,133 anal sex acts without a condom with an HIV-positive partner. Of the 693 new HIV infections, 51% were through anal sex with a condom, 33% anal sex without a condom and 16% oral sex. For anal sex with a condom, the 95% confidence limits were 17% and 77%.

Conclusions

The proportion of HIV infections related to condom failure appears substantial and higher than previously thought. That 51% of transmissions occur despite condom use may be conservative (i.e. low) since we used a relatively high estimate (87.1%) for condom effectiveness. If condom effectiveness were closer to 70%, a value estimated from a recent CDC study, the number and proportion of HIV transmissions occurring despite condom use would be much higher. Therefore, while condom use should continue to be promoted and enhanced, this alone is unlikely to stem the tide of HIV infection among MSM.     

Prevalence and Associated Factors of Unprotected Anal Intercourse with Regular Male Sex Partners among HIV Negative Men Who Have Sex with Men in China: A Cross-Sectional Survey

The HIV prevalence and incidence among men who have sex with men (MSM) in China are high. Unprotected anal intercourse (UAI) with a regular male sex partner (RP), a significant predictor of HIV sero-conversion, was high yet under-emphasized among MSM having RP (MSMRP). The present cross-sectional survey interviewed 307 HIV negative MSMRP recruited through convenient sampling from multiple sources, including venue-based outreaching, online recruitment, and referrals made by peers, in Beijing and Chengdu, China. Among MSMRP, the prevalence of UAI with RP in the last three months was 52.4%. The results of the multivariate analysis showed that trust and intimacy within the relationship with RP and presence of clinical depression symptoms were positively associated with UAI with RP in the last three months. Other associated scalar factors derived from the Theory of Planned Behavior were related to perceptions on condom use, including positive attitudes toward condom use (a negative association), subjective norm of the perception that MSM do not usually use condoms during anal intercourse with RP (a positive association), perceived behavioral control over condom use with RP (a negative association), and behavioral intention to use condoms with RP in the coming three months (a negative association). It is seen that MSMRP were at high risk of HIV/STD transmission. The associated factors hence involved those related to perceptions about condom use, mental health, and interpersonal relationship. Future interventions should take these multi-dimensional factors into account. In particular, future research to test the efficacy of couple-based interventions that include mental health elements needs to be conducted, as trust and intimacy within the relationship were associated with UAI among MSMRP, and mental health problems may exist for both the MSMRP and their RP.     

Prevalence of and Factors Associated with Rectal-Only Chlamydia and Gonorrhoea in Women and in Men Who Have Sex with Men

Background

Both anorectal Chlamydia trachomatis (CT) and Neisseria gonorrhoea (NG) can occur as a rectal-only infection or concurrently with simultaneous urogenital infection with the same pathogen. Characterising the target groups in which rectal-only infections occur may improve the efficacy of screening practices.

Methods

We analysed data from two Dutch outpatient sexually transmitted infection (STI) clinics between 2011 and 2012. We included all men who have sex with men (MSM) (n = 9549) and women (n = 11113), ≥18 years, who had been tested for anorectal and urogenital CT and/or NG (either as a result of reporting anal sex/symptoms or via routine universal testing). Factors associated with rectal-only CT and NG infections were assessed using univariable and multivariable logistic regression.

Results

In MSM, anorectal CT prevalence was 9.8% (693/7094), anorectal NG prevalence was 4.2% (397/9534). In women this was 9.5% overall (439/4597) and 0.9% (96/10972) respectively. Anorectal CT prevalence among women who were routinely universally tested was 10.4% (20/192), for selective testing this was 9.5% (419/4405) (p = 0.68). Anorectal NG infections were not detected among women who were routinely universally tested (p = 0.19). Among CT or NG positive MSM, rectal-only CT infections were found in 85.9% (595/693), for NG this was 85.6% (340/397) respectively. In positive women these figures were 22.1% (97/439)for CT and 20.8% (20/96) for NG, respectively. In MSM, independent factors associated with rectal-only CT were: being a sex worker (OR0.4,CI0.2–1.0), exclusively having sex with men (OR3.4,CI1.7–6.8), and absence of urogenital symptoms (OR0.2,CI0.2–0.4). In women, these factors were: older age (OR2.3, CI1.3–4.0) and non-Western nationality (OR1.8, CI1.0–3.5). Factors associated with rectal-only NG in MSM were: having been warned for STIs by an (ex) partner (OR2.9,CI1.1–7.5), oropharyngeal NG infection (OR2.4,CI1.0–5.3), and absence of urogenital symptoms (OR0.02,CI0.01–0.04), while in women no significant factors were identified.

Conclusions

The prevalence of anorectal CT and NG was substantial in MSM and prevalence of anorectal CT was also substantial in women. Anorectal infections occurred mostly as rectal-only infections in MSM and mostly concurrent with other infections in women. Given the lack of useful indicators for rectal-only infections, selective screening based on a priori patient characteristics will have low discriminatory power both in relation to MSM and women.     

Prevalence of Sexual Victimization and Correlates of Forced Sex in Japanese Men Who Have Sex with Men

Studies of men who have sex with men (MSM) in diverse geographic and cultural contexts have identified health challenges affecting this population. MSM might be particularly vulnerable to sexual victimization and forced sex. The aim of this research study was to examine prevalence of sexual victimization and correlates of forced sex among Japanese MSM. We recruited a sample of 5,731 Japanese MSM who completed an internet-administered survey. Participants reported on history of different types of sexual victimization, unprotected anal sex, other health risk behaviors, exposure to gay-related teasing and bullying, depression, and suicidality. Over one-fifth of the sample (21.4%) reported experiencing at least one form of sexual victimization, and 8.7% reported a history of forced sex. MSM who had ever experienced forced sex were significantly more likely to report experiencing psychological risks (depression OR = 1.55, 95% CI = 1.28–1.89; attempted suicide OR = 2.25, 95% CI = 1.81–2.81; other forms of bullying OR = 1.38, 95% CI = 1.13–1.68) and other behavioral risks (unprotected anal sex OR = 1.56, 95% CI = 1.29–1.90; sex venue attendance OR = 1.27, 95% CI = 1.04–1.54; methamphetamine use OR = 1.57, 95% CI  = 1.05–1.36), compared to MSM who had not experienced forced sex. Efforts to develop holistic and integrated health services for Japanese MSM are warranted, particularly related to psychosocial determinants of HIV prevention. However, due to cultural factors that emphasize familial and social relations and that stigmatize same-sex behavior, Japanese MSM might experience challenges to seeking social support and health services. Interventions must be provided in safe and non-judgmental settings where Japanese MSM feel comfortable disclosing their health and social support needs.     

Examining Levels of Risk Behaviors among Black Men Who Have Sex with Men (MSM) and the Association with HIV Acquisition

Seroadaptation is defined as the practice of modifying sexual behavior based on one’s own HIV serostatus, the perceived HIV serostatus of sexual partners, and differences in risk of HIV transmission by sexual acts. Because this definition implies intent, we use the term “seroprotection” to describe HIV negative participants reporting condomless anal sex (CAS) either exclusively with seronegative partners, or only as the insertive partner with HIV positive or unknown serostatus partners. Little is known about seroprotection in Black men who have sex with men (MSM). We evaluated the independent association of seroprotection and HIV acquisition among the 1144 HIV-negative Black MSM enrolled in HPTN 061 using Cox models; we stratified by city of enrollment, and controlled for number of partners, age, and drug use. Behaviors reported at 0, 6, and 12 months were assigned to three mutually exclusive categories: (1) No CAS; (2) Seroprotection; and (3) CAS without seroprotection. In 2,861 six-month intervals; 28 HIV seroconversions occurred. No CAS was reported at 33.3% of visits, seroprotection at 46.6% of visits, and CAS without seroprotection at 20.1% of visits. The seroconversion rate per 100 person-years for no CAS was 0.98 (95% CI: 0.27, 2.51), compared with 2.39 (95% CI: 1.03, 4.71) and 13.33 (95% CI: 7.62, 21.66) for seroprotection and CAS without seroprotection, respectively. Compared to CAS without seroprotection, intervals without CAS were associated with an 87% reduction (aHR: 0.13, 95% CI: 0.03–0.46) in HIV acquisition and intervals with seroprotection with a 78% reduction (aHR: 0.22, 95% CI: 0.09–0.57). No CAS is the safest behavior to prevent HIV acquisition. Seroprotective behaviors significantly reduced risk, but HIV incidence was still >2/100 person-years, suggesting that additional strategies, such as pre-exposure prophylaxis, are warranted for this population.     

Incidence of HIV and Syphilis among Men Who Have Sex with Men (MSM) in Beijing: An Open Cohort Study

Background

This study investigated HIV and syphilis incidence among men who have sex with men (MSM) in Beijing, China.

Methods

An open cohort was established from September 2009 to April 2012. Participants were followed up with every three to four months after recruitment and for thirty-one months in total. Chi-square tests were used to compare demographic and behavioral characteristics between participants who were followed up with and those lost to follow up. Univariate and multivariate Cox proportional hazards regression analyses were used to examine demographic and behavioral associations with HIV and syphilis incidence.

Results

69.7% (699/1,003) of the participants finished at least two follow-up surveys during the study period. Variables which corresponded to increased loss to follow-up included younger age, less education, non-identification of homosexual identity, and migrant status. A total of 1,045 person-years (PYs) and 1,016.4 PYs were followed up for HIV and syphilis incidence estimation, respectively. The HIV incidence was 5.9 per 100 PYs and 7.8 per 100 PYs for syphilis. The predictors for the high HIV incidence included unsafe anal sex, sex after drinking alcohol and STI infection.

Conclusion

HIV incidence increased rapidly within the cohort, but syphilis incidence remained stable and decreased. More research is needed to provide multi-pronged HIV prevention interventions among MSM in order to reduce the increasing burden of HIV and sexually transmitted infections (STIs) in China.     

Factors Affecting the Prevalence of Strongly and Weakly Carcinogenic and Lower-Risk Human Papillomaviruses in Anal Specimens in a Cohort of Men Who Have Sex with Men (MSM)

Background

MSM are at higher risk for invasive anal cancer. Twelve human papillomaviruses (HPVs) cause cervical cancer in women (Group 1 high-risk HPVs (hrHPVs)) and 13 HPVs are probable/possible causes (Group 2 hrHPVs) of cervical malignancy. HPVs rarely associated with malignancy are classified as lower-risk HPVs (lrHPVs).

Materials and Methods

Dacron-swab anal-cytology specimens were collected from and data complete for 97% (1262/1296) of Multicenter AIDS Cohort Study (MACS) men tested for HPVs using the Linear Array assay. Multivariate Poisson regression analyses estimated adjusted prevalence ratios for Group 1/2 hrHPVs and lrHPVs, controlling for the effects of age, race, ethnicity, sexual partnerships, smoking; HIV-infection characteristics, treatment, and immune status among HIV-infected men.

Results

HIV-infected men showed 35–90% higher prevalence of Group 1/2 hrHPVs and lrHPVs than HIV-uninfected men, and higher prevalence of multi-Type, and multiple risk-group infections. CD4+ T-cell count was inversely associated with HPV Group 2 prevalence (p<0.0001). The number of receptive anal intercourse (RAI) partners reported in the 24 months preceding HPV testing predicted higher prevalence of Group 1/2 hrHPVs. Men reporting ≥30 lifetime male sex partners before their first MACS visit and men reporting ≥1 RAI partners during the 24 months before HPV testing showed 17–24% and 13–17% higher prevalence of lrHPVs (p-values ≤0.05). Men reporting smoking between MACS visit 1 and 24 months before HPV testing showed 1.2-fold higher prevalence of Group 2 hrHPVs (p = 0.03). Both complete adherence to CART (p = 0.02) and HIV load <50 copies/mL (p = 0.04) were protective for Group 1 hrHPVs among HIV-infected men.

Conclusions

HIV-infected men more often show multi-type and multi-group HPV infections HIV-uninfected men. Long-term mutual monogamy and smoking cessation, generally, and CART-adherence that promotes (HIV) viremia control and prevents immunosuppression, specifically among HIV-infected MSM, are important prevention strategies for HPV infections that are relevant to anal cancer.     

Social Networking Smartphone Applications and Sexual Health Outcomes among Men Who Have Sex with Men

Several smartphone applications (apps) designed to help men who have sex with men (MSM) find casual sexual partners have appeared on the market recently. Apps of this nature have the potential to impact sexual health and behavior by providing constant access to a large supply of available partners. In this study, the sexual health history, behavior, and personality of MSM who use these apps was compared to MSM who meet partners in other ways. A sample of 110 adult MSM was recruited online to complete a cross-sectional survey. All participants were either single or involved in a non-exclusive romantic relationship. There were no statistically significant differences between app users and non-users in frequency of insertive or receptive anal sex without a condom. However, app users reported significantly more sexual partners and had a higher prevalence of ever being diagnosed with an STI than did non-users. App users did not differ from non-users on any demographic or personality variables (including erotophilia, sensation seeking, and self-control); however, when adjusting lifetime total sex partners for those met specifically through apps, app users still had significantly more partners. This pattern of results suggests that app users may be more sexually active in general. More work is needed to fully understand the association between this emerging technology and potential sexual health risks.     

Prevalence of Unprotected Anal Intercourse among Men Who Have Sex with Men in China: An Updated Meta-Analysis

Objective

The purpose of this review was to assess the prevalence of unprotected anal intercourse (UAI) among men who have sex with men (MSM) in China.

Methods

A comprehensive search was conducted including online databases like “Wanfang”, Chinese National Knowledge Infrastructure, PubMed and manual searches. Analyses using random-effects models were performed to estimate the prevalence of UAI among MSM in China.

Results

Sixty-two articles reporting eighty-two studies were selected. The pooled prevalence rates of UAI with any male partner, with regular male partners, with non-regular male partners, with casual male partners, and with commercial male partners among MSM were 53%(95%CI: 51–56%), 45%(95%CI: 39–51%), 34%(95%CI: 24–45%), 33%(95%CI: 30–36%), 12% (95%CI: 5–26%), respectively. A cumulative meta-analysis found that the pooled UAI prevalence decreased over time.

Conclusions

Although the prevalence of UAI with male partners among MSM in China presents a decreasing trend over the past decade, the concomitant rise in HIV prevalence and incidence indicates that current prevention intervention efforts are insufficient to effectively contain the spread of HIV. Therefore, the persistently high prevalence of risky sexual behaviors underscores the need for innovative and effective prevention strategies among MSM.     

Heterogeneous Evolution of HIV-1 CRF01_AE in Men Who Have Sex with Men (MSM) and Other Populations in China

Introduction

The HIV epidemic in men who have sex with men (MSM) continues to grow in most countries. However, the phylodynamic and virological differences among HIV-1 strains circulating in MSM and other populations are not well characterized.

Methods

Nearly full-length genomes (NFLGs) of the HIV-1 CRF01_AE were obtained from the Los Alamos HIV database. Phylogenetic analyses were conducted using the NFLG, gag, pol and env genes, using the maximum likelihood method. Selection pressure analyses at the codon level were performed for each gene in the phylogenetic clusters using PAML.

Results

Sequences isolated from MSM in China clustered in Clusters 1 (92.5%) and 2 (85.71%). The major risk factor for Cluster 3 was heterosexual transmission (62.16%). The ratio of non-synonymous to synonymous substitutions in the env gene (0.7–0.75) was higher than the gag (0.26–0.34) or pol (0.21–0.26) genes. In env gene, Cluster 1 (4.56×10^-3subs/site/year) and 2 (6.01×10^-3subs/site/year) had higher evolutionary rates than Cluster 3 (1.14×10^-3subs/site/year). Positive selection affected 4.2–6.58% of the amino acid sites in the env gene. Two sites (HXB2:136 and 316) evolved similarly in Clusters 1 and 2, but not Cluster 3.

Conclusion

The HIV-1 CRF01_AE in MSM is evolving differently than in other populations.     

Sexual Seroadaptation: Lessons for Prevention and Sex Research from a Cohort of HIV-Positive Men Who Have Sex with Men

Background

Surveillance data on sexually transmitted infections (STIs) and behavioral characteristics identified in studies of the risk of seroconversion are often used as to track sexual behaviors that spread HIV. However, such analyses can be confounded by “seroadaptation”—the restriction of unprotected anal intercourse (UAI), especially unprotected insertive UAI, to seroconcordant partnerships.

Methods

We utilized sexual network methodology and repeated-measures statistics to test the hypothesis that seroadaptive strategies reduce the risk of HIV transmission despite numerous partnerships and frequent UAI.

Principal Findings

In a prospective cohort study of HIV superinfection including 168 HIV-positive men who have sex with men (MSM), we found extensive seroadaptation. UAI was 15.5 times more likely to occur with a positive partner than a negative one (95% confidence interval [CI], 9.1–26.4). Receptive UAI was 4.3 times more likely in seroconcordant partnerships than with negative partners (95% CI, 2.8–6.6), but insertive UAI was 13.6 times more likely with positives (95% CI, 7.2–25.6). Our estimates suggest that seroadaptation reduced HIV transmissions by 98%.

Conclusion

Potentially effective HIV prevention strategies, such as seroadaptation, have evolved in communities of MSM before they have been recognized in research or discussed in the public health forum. Thus, to be informative, studies of HIV risk must be designed to assess seroadaptive behaviors rather than be limited to individual characteristics, unprotected intercourse, and numbers of partners. STI surveillance is not an effective indicator of trends in HIV incidence where there are strong patterns of seroadaptation.     

Factors Associated with Loss-to-Follow-Up during Behavioral Interventions and HIV Testing Cohort among Men Who Have Sex with Men in Nanjing,China

Background

Behavioral interventions (BIs) remained the cornerstone of HIV prevention in resource-limited settings. One of the major concerns for such efforts is the loss-to-follow-up (LTFU) that threatens almost every HIV control program involving high-risk population groups.

Methods

To evaluate the factors associated with LTFU during BIs and HIV testing among men who have sex with men (MSM), 410 HIV sero-negatives MSM were recruited using respondent driven sampling (RDS) in Nanjing, China during 2008, they were further followed for 18 months. At baseline and each follow-up visits, each participant was counseled about various HIV risk-reductions BIs at a designated sexually transmitted infection (STI) clinic.

Results

Among 410 participants recruited at baseline, altogether 221 (53.9%) were LTFU at the 18-month follow-up visit. Overall, 46 participants were found to be positive for syphilis infection at baseline while 13 participants were HIV sero-converted during the follow-up period. Increasing age was less (Adjusted Odds Ratio(aOR) of 0.90, 95% confidence Interval (CI) 0.86–0.94) and official residency of provinces other than Nanjing (AOR of 2.49, 95%CI 1.32–4.71), lower level of education (AOR of 2.01, 95%CI 1.10–3.66) and small social network size (AOR of 1.75, 95%CI 1.09–2.80) were more likely to be associated with higher odds of LTFU.

Conclusion

To improve retention in the programs for HIV control, counseling and testing among MSM in Nanjing, focused intensified intervention targeting those who were more likely to be LTFU, especially the young, less educated, unofficial residents of Nanjing who had smaller social network size, might be helpful.     

A New Perspective on Sexual Mixing among Men Who Have Sex with Men by Body Image

Background

“Casual sex” is seldom as non-selective and random as it may sound. During each sexual encounter, people consciously and unconsciously seek their casual sex partners according to different attributes. Influential to a sexual network, research focusing on quantifying the effects of physical appearance on sexual network has been sparse.

Methods

We evaluated the application of Log odds score (LOD) to assess the mixing patterns of 326 men who have sex with men (MSM) in Hong Kong in their networking of casual sex partners by Body Image Type (BIT). This involved an analysis of 1,196 respondents-casual sex partner pairs. Seven BITs were used in the study: Bear, Chubby, Slender, Lean toned, Muscular, Average and Other.

Results

A hierarchical pattern was observed in the preference of MSM for casual sex partners by the latter''s BIT. Overall, Muscular men were most preferred, followed by Lean toned while the least preferred was Slender, as illustrated by LOD going down along the hierarchy in the same direction. Marked avoidance was found between men who self-identified as Chubby and men of Other body type (within-group-LOD: 1.25–2.89; between-group-LOD: <−1). None of the respondents reported to have networked a man who self-identified as Average for casual sex.

Conclusions

We have demonstrated the possibility of adopting a mathematical prototype to investigate the influence of BIT in a sexual network of MSM. Construction of matrix based on culture-specific BIT and cross-cultural comparisons would generate new knowledge on the mixing behaviors of MSM.