Sexual mixing patterns among social networks of HIV-positive and HIV-negative Beijing men who have sex with men: a multilevel comparison using roundtable network mapping

Generating a heterosexual bipartite network embedded in social network

We describe an approach to generate a heterosexual network with a prescribed joint-degree distribution embedded in a prescribed large-scale social contact network. The structure of a sexual network plays an important role in how all sexually transmitted infections (STIs) spread. Generating an ensemble of networks that mimics the real-world is crucial to evaluating robust mitigation strategies for controlling STIs. Most of the current algorithms to generate sexual networks only use sexual activity data, such as the number of partners per month, to generate the sexual network. Real-world sexual networks also depend on biased mixing based on age, location, and social and work activities. We describe an approach to use a broad range of social activity data to generate possible heterosexual networks. We start with a large-scale simulation of thousands of people in a city as they go through their daily activities, including work, school, shopping, and activities at home. We extract a social network from these activities where the nodes are the people, and the edges indicate a social interaction, such as working in the same location. This social network captures the correlations between people of different ages, living in different locations, their economic status, and other demographic factors. We use the social contact network to define a bipartite heterosexual network that is embedded within an extended social network. The resulting sexual network captures the biased mixing inherent in the social network, and models based on this pairing of networks can be used to investigate novel intervention strategies based on the social contacts among infected people. We illustrate the approach in a model for the spread of chlamydia in the heterosexual network representing the young sexually active community in New Orleans.

Reconstructing the social network of HIV key populations from locally observed information

Traditional surveys only provide local observations about the topological structure of isolated individuals. This study aims to develop a novel data-driven approach to reconstructing the social network of men who have sex with men (MSM) communities from locally observed information by surveys. A large social network consisting of 1075 users and their public relationships was obtained manually from BlueD.com. We followed the same survey-taking procedure to sample locally observed information and adapted an Exponential Random Graph Model (ERGM) to model the full structure of the BlueD social network (number of local nodes N = 1075, observed average degree k = 6.46). The parameters were learned and then used to reconstruct the MSM social networks by two real-world survey datasets in Hong Kong (N = 600, k = 5.61) and Guangzhou (N = 757, k = 5). Our method performed well on reconstructing the BlueD social network, with a high accuracy (90.3%). In conclusion, this study demonstrates the feasibility of using parameters learning methods to reconstruct the social networks of HIV key populations. The method has the potential to inform data-driven intervention programs that need global social network structures.

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.

Characteristics of men who engage in cross-generational sexual behaviour in Nigeria

Cross-generational sexual relationships are a major route of transmitting HIV and STI between older and younger generations. However, previous research has focused mainly on the young women in these relationships. This study examined the characteristics of men engaging in non-marital sexual relationships with girls aged 15-19 in Nigeria. The data were drawn from the 2013 Nigeria Demographic and Health Survey, and the analysis was restricted to a sub-sample of 7557 men aged 30-49 who were sexually active in the 12 months prior to the survey. Data analysis was carried out using frequency distributions, chi-squared tests of association and binary logistic regression. It was found that 9.5% of men aged 30-49 reported engaging in cross-generational sexual relationships. Also, being older (OR = 0.35), married (OR = 0.37), having secondary or higher education (OR = 0.70; 0.59) and having sexual debut between ages 18 and 30 (OR = 0.73) were associated with a lower likelihood of having cross-generational sexual relationships. However, Muslim men (OR = 2.10), men from Igbo (OR = 1.90), Hausa/Fulani (OR = 8.47) and Northern and Southern minority tribes (OR = 4.73; 2.49), men living in rural areas (OR = 1.34), men who were over the age of 30 at sexual debut (OR = 2.67) and those with 2-4 and 5 or more lifetime sexual partners (OR = 1.43; 1.58) were significantly more likely to engage in cross-generational sexual relationships. Addressing the challenges of cross-generational sexual relationships can be an effective strategy to reduce the menace of HIV and STI transmission. Men who have low education, those aged 30-34 years, those who initiated sex at an older age, rural dwellers and those who have had several lifetime sexual partners need to be targeted while designing and implementing programmes and policies to reduce cross-generational sexual relationships in Nigeria. These interventions must also take into account the religious and cultural attitudes towards cross-generational sexual relationships, and further investigations should identify men's motives for engaging in the practice.

Potential effectiveness of prophylactic HPV immunization for men who have sex with men in the Netherlands: A multi-model approach

BACKGROUND

Men who have sex with men (MSM) are at high risk for anal cancer, primarily related to human papillomavirus genotype 16 (HPV16) infections. At 8.5 per 100,000 per year, the incidence rate of anal cancer among MSM is similar to that of cervical cancer among adult women in the Netherlands. However, MSM are not included in most HPV vaccination programs. We explored the potential effectiveness of prophylactic immunization in reducing anogenital HPV16 transmission among MSM in the Netherlands.

METHODS AND FINDINGS

We developed a range of mathematical models for penile-anal HPV16 transmission, varying in sexual contact structure and natural history of infection, to provide robust and plausible predictions about the effectiveness of targeted vaccination. Models were informed by an observational cohort study among MSM in Amsterdam, 2010-2013. Parameters on sexual behavior and HPV16 infections were obtained by fitting the models to data from 461 HIV-negative study participants, considered representative of the local MSM population. We assumed 85% efficacy of vaccination against future HPV16 infections as reported for HIV-negative MSM, and age-specific uptake rates similar to those for hepatitis B vaccination among MSM in the Netherlands. Targeted vaccination was contrasted with vaccination of 12-year-old boys at 40% uptake in base-case scenarios, and we also considered the effectiveness of a combined strategy. Offering vaccine to MSM without age restrictions resulted in a model-averaged 27.3% reduction (90% prediction interval [PI] 11.9%-37.5%) in prevalence of anal HPV16 infections, assuming similar uptake among MSM as achieved for hepatitis B vaccination. The predicted reduction improved to 46.1% (90% PI 21.8%-62.4%) if uptake rates among MSM were doubled. The reductions in HPV16 infection prevalence were mostly achieved within 30 years of a targeted immunization campaign, during which they exceeded those induced by vaccinating 40% of preadolescent boys, if started simultaneously. The reduction in anal HPV16 prevalence amounted to 74.8% (90% PI 59.8%-93.0%) under a combined vaccination strategy. HPV16 prevalence reductions mostly exceeded vaccine coverage projections among MSM, illustrating the efficiency of prophylactic immunization even when the HPV vaccine is given after sexual debut. Mode of protection was identified as the key limitation to potential effectiveness of targeted vaccination, as the projected reductions were strongly reduced if we assumed no protection against future infections in recipients with prevalent infection or infection-derived immunity at the time of immunization. Unverified limitations of our study include the sparsity of data to inform the models, the omission of oral sex in transmission to the penile or anal site, and the restriction that our modeling results apply primarily to HIV-negative MSM.

CONCLUSIONS

Our findings suggest that targeted vaccination may generate considerable reductions in anogenital HPV16 infections among MSM, and has the potential to accelerate anal cancer prevention, especially when combined with sex-neutral vaccination in preadolescence.

Uptake of a Partner Notification Model for HIV Among Men Who Have Sex With Men and Transgender Women in Tijuana, Mexico

Undiagnosed HIV infection is common among men who have sex with men (MSM) and transgender women (TW) in Latin America. We examined uptake of a partner notification (PN) model among MSM and TW in Tijuana, Mexico. Forty-six HIV-positive MSM/TW enrolled as index patients, and reported 132 MSM/TW sexual partners for PN. Of notified partners (90/132), 39% declined eligibility screening or participation, 39% tested for HIV, and of those 28% were newly-diagnosed HIV-positive. Partners who were seen by the index patient more than once in the past 4 months and those who primarily had sex with the index patient in one of their homes were more likely to be notified via PN (76% vs. 50%; p = 0.01 and 86% vs. 64%, p = 0.02, respectively). Lower than expected PN uptake was associated with problems identifying index patients, obtaining reliable partner contact information, and engaging notified partners.

Sex with older partners, condomless anal sex and unrecognized HIV infection among Chinese men who have sex with men

We examined the prevalence of sex with older male partner (SWOMP) and its association with condomless anal intercourse (CAI) with male partners and unrecognized HIV infection among young men who have sex with men (MSM) in Shanghai, China. The analytic sample included 243 MSM who were 18-45 years and HIV negative or of unknown HIV serostatus. Older male partner refers to male sex partner who was at least 10 years older than themselves. Overall, 99 (43.0%) and 50 (20.7%) reported having SWOMP in lifetime and in the last 3 months, respectively. Having any CAI with male partners in the last 3 months was independently associated with SWOMP and sex with stable male partners in the last 3 months. Unrecognized HIV infection was independently associated with being HSV-2 positive and having any CAI with male partners as well as SWOMP in last 3 months. Sex with stable male partner in the last 3 months was also marginally significantly associated with unrecognized infection (p = 0.084). Older partner selection is common among young MSM in China. Prevention programs should incorporate education messages about the HIV risk associated with SWOMP. MSM should be informed that having condomless sex with stable partners may place them at HIV risk.

Substance use and HIV-risk behaviors among HIV-positive men who have sex with men in China: repeated measures in a cohort study design

Global literature revealed that seropositive men who have sex with men (MSM) posed an even higher risk compared to their seronegative counterparts. Identifying risk factors that contribute to HIV-risk behaviors will help to curb the rapid HIV transmission among this group. Our hypothesis was that MSM with substance use were more likely to conduct HIV-risk behaviors, even after accounting for repeated measures. In the current study, we employed a cohort study design by following a group of 367 HIV-positive MSM up to four visits for one year to collect information regarding their sexual behaviors and history of substance use in the past three months. We used Generalized Estimating Equations (GEE) models to account both within- and between-subject variation when assessing associations between substance use and HIV-risk behaviors. A total of 367 MSM were included at the baseline with a mean age of 29.6 years. After accounting for potential confounders and time-varying effects, our models indicated that drug and alcohol use increase HIV risks at the population level by increasing risks of drinking alcohol before sex, having unprotected sex with men and seropositive partners, having more lifetime female sex partners and having a higher number of male sexual partners in the past three months. The current study is one of the first studies with repeated measures to evaluate the association between substance use and sexual risk behaviors among MSM in China. Findings in the current study have several implications for future research. We call for more rigorous study design for future research to better capture changes of risky behaviors among this at-risk population.

Predictors of antiretroviral therapy initiation: a cross-sectional study among Chinese HIV-infected men who have sex with men

Background

Early antiretroviral therapy (ART) initiation is crucial to achieve HIV viral suppression and reduce transmission. HIV-infected Chinese men who have sex with men (MSM) were less likely to initiate ART than other HIV-infected individuals. We assessed predictors of ART initiation among Chinese MSM.

Methods

In 2010–2011, a cross-sectional study was conducted among MSM in Beijing, China. We examined ART initiation within the subgroup who were diagnosed with HIV infection prior to participation in the survey. Logistic regression models were fitted to evaluate socio-demographic and behavioral factors associated with ART initiation. The eligibility criterion in the 2010/2011 national HIV treatment guidelines was CD4 cell count <350 cells/μL or World Health Organization (WHO) clinical stage III/IV.

Results

Of 238 eligible HIV-infected participants, the median duration of HIV infection was 15 months (range: 31 days-12 years); 62 (26.1 %) had initiated ART. Among 103 men with CD4 counts <350 cells/μL, 38 (36.9 %) initiated ART. Being married to a woman (adjusted odd ratios [aOR]: 2.50; 95 % confidence interval [CI]: 1.07-5.87), longer duration of HIV infection (aOR: 10.71; 95 % CI: 3.66-31.32), and syphilis co-infection (aOR: 2.58; 95 % CI: 1.04-6.37) were associated with a higher likelihood of ART initiation. Of 135 men with CD4 count ≥350 cells/μL, 24 (18 %) initiated ART. Being married to a woman (aOR: 4.21; 95 % CI: 1.60-11.06), longer duration of HIV infection (aOR: 22.4; 95 % CI: 2.79-180), older age (aOR: 1.26; 95 % CI: 1.1-1.44), Beijing Hukou (aOR: 4.93; 95 % CI: 1.25-19.33), presence of AIDS-like clinical symptoms (aOR: 3.97; 95 % CI: 1.32-14.0), and history of sexually transmitted infections (aOR: 4.93; 95 % CI: 1.25-19.43) were associated with ART initiation. Compared with men who did not initiated ART, those with ART were more likely to receive counseling on benefits of ART (96.8 % vs. 66.4 %, P = 0 < 0.01), HIV stigma coping strategy (75.8 % vs. 65.9 %, P = 0.04), mental health (66.1 % vs. 52.9 %, P = 0.02), and substance use (46.7 % vs. 36.6 %, P = 0.04).

Conclusions

We documented low rates of ART initiation among Chinese MSM. Policy changes for expanding ART eligibility and interventions to improve the continuum of HIV care are in progress in China. Impact evaluations can help assess continuing barriers to ART initiation among MSM.

A comparative analysis of behaviors and sexual affiliation networks among men who have sex with men in Hong Kong

In Hong Kong, men who have sex with men (MSM) account for a significant proportion of HIV infections. While perceived as a hidden population, they constitute a distinct social network shaped by their differential use of unique channels for sex partnership. To characterize their pattern of connectivity and association with high-risk sexual behaviors, 311 MSM were recruited via saunas and the internet to participate in a questionnaire survey. Internet recruits were younger, and many (31/43) were solely reliant on the internet to seek sex partners, while visiting a similar number of venues as the sauna recruits (p = 0.98). Internet users generally had a high frequency of unprotected anal intercourse (UAI). MSM who had visited only a single venue reported more UAI with their regular partners (adjusted OR 6.86, 1.88-24.96) and sought fewer casual partners than those frequenting multiple venues (adjusted OR 0.33, 0.19-0.60). This study provides evidence for the heterogeneity of the sexual affiliation networks of MSM in Hong Kong. High HIV risk of UAI could be offset by fewer casual partners in certain venues, the implications of which would need to be explored in longitudinal studies. Methodologically, internet sampling was very efficient in identifying sex networking venues, while internet recruits gave a high retention rate for updating profiles. However, sampling at high centrality saunas did not necessarily identify the MSM-affiliating venues in the networks efficiently. The sampling strategy of MSM survey should therefore be objective-driven, which may differ for health message dissemination and social marketing, versus HIV surveillance or risk assessment.

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.

Sexual partner mixing and differentials in consistent condom use among men who have sex with men in Maharashtra, India

Sexual partner mixing among men who have sex with men (MSM), based on both gender and partnership status, is an understudied theme in India. Using data from Round 2 of the Integrated Bio-behavioral Survey, this paper reports on gender and partnership status-based sexual mixing and levels of consistent condom use (CCU) among MSM in Maharashtra. A total of 689 MSM were sampled using probability-based sampling. Bivariate and regression analyses were carried out on condom use and partnership mixing. Over half (52%) of all MSM reported having only male partners while about one-third (34.5%) reported having partners of both gender. Over 70% of MSM engaged in sex with a mix of casual, regular, commercial and non-commercial partners. MSM with only male partners reported lower CCU as compared to MSM with partners of both genders (47.3% and 62%, respectively, p = 0.11). CCU levels differed significantly by status of sex partner. Overall, MSM having 'men only' as partners and those with partners of mixed status have greater risk behaviour in terms of low CCU. HIV prevention interventions need to focus attention on men in 'exclusively male' sex partnerships as well as MSM with a mix of casual, regular and commercial partners.

Social networks, sexual networks and HIV risk in men who have sex with men

Worldwide, men who have sex with men (MSM) remain one of the most HIV-vulnerable community populations. A global public health priority is developing new methods of reaching MSM, understanding HIV transmission patterns, and intervening to reduce their risk. Increased attention is being given to the role that MSM networks play in HIV epidemiology. This review of MSM network research studies demonstrates that: (1) Members of the same social network often share similar norms, attitudes, and HIV risk behavior levels; (2) Network interventions are feasible and powerful for reducing unprotected sex and potentially for increasing HIV testing uptake; (3) HIV vulnerability among African American MSM increases when an individual enters a high-risk sexual network characterized by high density and racial homogeneity; and (4) Networks are primary sources of social support for MSM, particularly for those living with HIV, with greater support predicting higher care uptake and adherence.

Emerging disparity in HIV/AIDS disease progression and mortality for men who have sex with men, Jiangsu Province, China

Few data exist on HIV disease progression and antiretroviral treatment (ART) impact among men who have sex with men (MSM) in China. Using data from the national case reporting system from 2004 to 2010, we describe changes in CD4 cell count before and after ART initiation, disease progression, and mortality among MSM in Jiangsu province compared with other persons living with HIV/AIDS. Median CD4 cell count among MSM at HIV diagnosis was 432 and decreased rapidly in 12 months to below the level of heterosexuals (slope: MSM -38.0, heterosexuals -15.5, injection drug users [IDU] -8.0, blood donors -10.5). Among those initiating ART, median CD4 cell count among MSM was 157, yet the increase in count was slower than for other groups (slope: MSM 26.9, heterosexuals 31.9, IDU 29.0, blood donors 35.0). Progression to AIDS was faster among MSM than heterosexuals and IDU. For the present, the mortality rate was lower for MSM compared with heterosexuals and blood donors; however, against a backdrop of more recent infection (ie, MSM had younger age, and 93.8 % were diagnosed after 2008), findings suggest a survival rate for MSM that will fall behind other groups. Improved medical and psychosocial supportive care is needed for this stigmatized population lest disparities become greater.

HIV vulnerabilities and coercive sex at same-sex sexual debut among men who have sex with men in Beijing, China

Few studies have examined coercive sex and HIV vulnerabilities among men who have sex with men (MSM) in China. The present study seeks to compare individual characteristics between MSM who did and did not experience coercive sex at their MSM sexual debut and to identify HIV risk factors correlated with coercive sex at MSM sexual debut. In 2007, we recruited 167 MSM in Beijing, China by peer-referred social network sampling. Each participant then completed self-administered questionnaires regarding their sexual experiences and practices. Results show that 14% of participants reported coercive sex at MSM sexual debut, of whom 48% reported recent unprotected anal intercourse (UAI). Coercive sex at MSM sexual debut was significantly associated with UAI [adjusted odds ratio (AOR): 5.38, 95% confidence interval: 1.95-14.87] and lifetime number of male sex partners (AOR: 7.25, 95% CI: 2.39-22.01). Coercive sex is harming MSM in China and should be immediately addressed by researchers, public health officials, and MSM community stakeholders.

Short communication: emerging transmitted HIV type 1 drug resistance mutations among patients prior to start of first-line antiretroviral therapy in middle and low prevalence sites in China

It is known that transmitted drug resistance (TDR) will most likely emerge in regions where antiretroviral therapy (ART) has been widely available for years. However, after a decade of rapid scale-up of ART in China, there are few data regarding TDR among HIV-infected patients prior to initiating first-line ART in China. A prospective, observational cohort study was performed at sentinel sites in five provinces or municipalities. Study participants were recruited at the county- or city-level centers for disease control (CDCs), during routine monitoring visits following referral from diagnosing parties (e.g., hospitals). Each province or municipality recruited 140 patients through sequential sampling throughout the 2011 calendar year. A total of 627 eligible subjects were included in the analysis. the median CD4(+) cell count was 206 cells/ml at the baseline survey. The majority of patients (93.5%) had plasma HIV viral load ≥1,000 copies/ml. Of the 627 patients, 17 (2.7%) had drug resistance mutations for any type of HIV drugs. The prevalence of drug resistance mutations to nonnucleoside reverse transcriptase inhibitor (NNRTI) drugs (8/627, 1.3%) was higher than to nucleoside reverse transcriptase inhibitor (NRTI) drugs (5/627, 0.8%) and protease inhibitor (PI) drugs (4/627, 0.6%). A logistic regression model showed that the only predictive factor was the route of infection through homosexual intercourse, i.e., men who have sex with men (MSM) status. As HIV prevalence is rising rapidly among Chinese MSM, it is essential to continue surveying this risk group and related high-risk populations with low awareness of HIV, and to develop new public health interventions that help to reduce the spread of drug-resistant HIV.

Substance Use and Sexual Risks Among General MSM and Money Boys in Shanghai, China

In China, men who have sex with men (MSM) are at high risk for substance use, HIV, and other sexually transmitted infections (STIs). However, there has been little research into their drug use and the sexual behaviors they engage in after drug and alcohol use. Using respondent-driven sampling methodology, this cross-sectional study of 404 MSM described drug use and examined sexual behaviors after drug and alcohol use among general MSM and money boys (those who engage in same-sex commercial sex) in Shanghai, China. Money boys reported using more drugs in the last week, 3 months and ever, and having sex after drinking and sex after using drugs more frequently than general MSM. It is vital to continue research and begin science-based interventions in these high-risk and underserved populations.