Yea-Hung Chen

Using Social Networks to Reach Black MSM for HIV Testing and Linkage to Care

Black men who have sex with men (MSM) are disproportionately affected by HIV infection. Black MSM in San Francisco may have higher rates of unrecognized HIV infections. Increased HIV testing among Black MSM may reduce the numbers of unrecognized infections, inform more men of their status and thus reduce the potential for ongoing transmissions. Social network HIV testing programs have focused on asking HIV-positive and/or high-risk negative men to recruit their social or sexual contacts. We used a network approach to deliver HIV testing to Black MSM in San Francisco and collected risk assessment data. Participants were asked to recruit any of their social contacts who were also Black MSM. Recruitment by risk level and HIV status was heterogeneous. HIV infection among this population is associated with older age, having a high school education or higher and currently being homeless. Fully 23% of HIV positive Black MSM are unaware of their infection. Only a third of unrecognized infections were recruited by a known HIV-positive participant. Linkage to care was a challenge and underscores the need for comprehensive systems and support to link Black MSM to care and treatment.

A new trend in the HIV epidemic among men who have sex with men, San Francisco, 2004-2011.

Background:In San Francisco, men who have sex with men (MSM) have historically comprised 90% of the HIV epidemic. It has been suggested that given the ongoing HIV transmission among this population, there is the possibility of a high-level endemic of HIV into the future. We report on the possibility of another phase in the HIV epidemic among MSM in San Francisco. Methods:Behavioral surveillance systems monitor HIV prevalence, HIV incidence, and behaviors among populations at high risk for HIV infection. Among MSM, time–location sampling is used to obtain samples for standardized behavioral surveys, HIV-antibody and incidence testing. We analyzed National HIV Behavioral Surveillance data from MSM sampled in 2004, 2008, and 2011. Results:Three hundred eighty-six, 521, and 510 MSM were enrolled in each of the waves. Only slight changes were seen in demographics over time. We detected significant declines in unrecognized HIV infection and methamphetamine use, a significant increase in HIV testing in the past 6 months, and no changes in HIV prevalence, history of gonorrhea infection, or having multiple sex partners. Among HIV-infected men, current antiretroviral treatment (ART) use seems to have risen from 2008 to 2011. Conclusions:The trends of the last 7 years point to stable HIV prevalence as rising ART coverage results in improving survival coupled with decreasing incidence as ART use achieves viral load suppression at levels more than sufficient to offset ongoing sexual risk behavior. “Treatment as prevention” may be occurring among MSM in San Francisco.

An empirical examination of respondent driven sampling design effects among HIV risk groups from studies conducted around the world.

For studies using respondent driven sampling (RDS), the current practice of collecting a sample twice as large as that used in simple random sampling (SRS) (i.e. design effect of 2.00) may not be sufficient. This paper provides empirical evidence of sample-to-sample variability in design effects using data from nine studies in six countries among injecting drug users, female sex workers, men who have sex with men and male-to-female transgender (MTF) persons. We computed the design effect as the variance under RDS divided by the variance under SRS for a broad range of demographic and behavioral variables in each study. We also estimated several measures for each variable in each study that we hypothesized might be related to design effect: the number of waves needed for equilibrium, homophily, and mean network size. Design effects for all studies ranged from 1.20 to 5.90. Mean design effects among all studies ranged from 1.50 to 3.70. A particularly high design effect was found for employment status (design effect of 5.90) of MTF in Peru. This may be explained by a “bottleneck”—defined as the occurrence of a relatively small number of recruitment ties between two groups in the population. A design effect of two for RDS studies may not be sufficient. Since the mean design effect across all studies was 2.33, an effect slightly above 2.00 may be adequate; however, an effect closer to 3.00 or 4.00 might be more appropriate.

Connecting the dots: examining transgender women's utilization of transition-related medical care and associations with mental health, substance use, and HIV.

Findings on access to general healthcare for transgender people have emerged, but little is known about access to transition-related medical care for transwomen (i.e., hormones, breast augmentation, and genital surgery). Transgender women have low access to general medical care and are disproportionately at risk for substance use, mental illness, and HIV. We conducted an analysis to determine if utilization of transition-related medical care is a protective factor for health risks to transgender women and to investigate if care differs by important demographic factors and HIV status. A secondary analysis was conducted using data from a 2010 HIV surveillance study using respondent-driven sampling to recruit 314 transwomen in San Francisco. Survey-corrected logistic regression models were used to estimate odds ratios for six psychosocial health problems—binge drinking, injection drug use, anxiety, depression, suicidal ideation, and high-risk intercourse—comparing various levels of utilization of transition-related medical care. Odds ratios were also calculated to determine if utilization of transition-related medical care was related to less overlap of risk domains. We found that Latina and African American transwomen had significantly lower estimated utilization of breast augmentation and genital surgery, as did transwomen who identified as transgender rather than female. Overall, utilization of transition-related medical care was associated with significantly lower estimated odds of suicidal ideation, binge drinking, and non-injection drug use. Findings suggest that utilization of transition-related medical care may reduce risk for mental health problems, especially suicidal ideation, and substance use among transwomen. Yet, important racial/ethnic and gender identity disparities in utilization of transition-related medical care need to be addressed.

Differential HIV Risk for Racial/Ethnic Minority Trans*female Youths and Socioeconomic Disparities in Housing, Residential Stability, and Education

OBJECTIVES We examined HIV prevalence and risk behaviors of 282 trans*female youths aged 16 to 24 years participating in the San Francisco Bay Area, California, SHINE study from 2012 to 2013 to determine differences between racial/ethnic minority and White youths. METHODS We conducted the χ(2) test to determine distributional differences between racial/ethnic minority and White participants in sociodemographic factors, HIV-related risk behaviors, and syndemic factors. RESULTS Of the trans*female youths, 4.8% were HIV positive. Racial/ethnic minority and White trans*female youths differed significantly in gender identity and sexual orientation. Racial/ethnic minority youths also had significantly lower educational attainment, were less likely to have lived with their parents of origin as a child, and were significantly more likely to engage in recent condomless anal intercourse than were Whites. CONCLUSIONS Efforts to assess the impact of multiple-minority stress on racial/minority trans*female youths are needed imminently, and prevention efforts must address macrolevel disparities for trans*female youths, especially those from racial/ethnic minority groups, to reduce these disparities and prevent incident cases of HIV.

A randomized control trial of personalized cognitive counseling to reduce sexual risk among HIV-infected men who have sex with men

Abstract The increased life expectancy and well-being of HIV-infected persons presents the need for effective prevention methods in this population. Personalized cognitive counseling (PCC) has been shown to reduce unprotected anal intercourse (UAI) with a partner of unknown or different serostatus among HIV-uninfected men who have sex with men (MSM). We adapted PCC for use among HIV-infected MSM and tested its efficacy against standard risk-reduction counseling in a randomized clinical trial in San Francisco. Between November 2006 and April 2010, a total of 374 HIV-infected MSM who reported UAI with two or more men of negative or unknown HIV serostatus in the previous 6 months were randomized to two sessions of PCC or standard counseling 6 months apart. The primary outcome was the number of episodes of UAI with a non-primary male partner of different or unknown serostatus in the past 90 days, measured at baseline, 6, and 12 months. Surveys assessed participant satisfaction with the counseling. The mean number of episodes of UAI at baseline did not differ between PCC and control groups (2.97 and 3.14, respectively; p=0.82). The mean number of UAI episodes declined in both groups at 6 months, declined further in the PCC group at 12 months, while increasing to baseline levels among controls; these differences were not statistically significant. Episode mean ratios were 0.76 (95% confidence interval [CI] 0.25–2.19, p=0.71) at 6 months and 0.48 (95% CI 0.12–1.84, p=0.34) at 12 months. Participants in both groups reported a high degree of satisfaction with the counseling. The findings from this randomized trial do not support the efficacy of a two-session PCC intervention at reducing UAI among HIV-infected MSM and indicate the continued need to identify and implement effective prevention methods in this population.

Balancing Theory and Practice in Respondent-Driven Sampling: A Case Study of Innovations Developed to Overcome Recruitment Challenges

Introduction Respondent-driven sampling (RDS) offers a recruitment strategy for hard-to-reach populations. However, RDS faces logistical and theoretical challenges that threaten efficiency and validity in settings worldwide. We present innovative adaptations to conventional RDS to overcome barriers encountered in recruiting a large, representative sample of men who have sex with men (MSM) who travel internationally. Methods Novel methodological adaptations for the “International Travel Research to Inform Prevention” or “I-TRIP” study were offering participants a choice between electronic and paper coupons referrals for recruitment and modifying the secondary incentives structure from small cash amounts to raffle entries for periodic large cash prize raffle drawings. Staged referral limit increases from 3 to 10 referrals and progressive addition of 70 seeds were also implemented. Results There were 501 participants enrolled in up to 13 waves of growth. Among participants with a choice of referral methods, 81% selected electronic referrals. Of participants who were recruited electronically, 90% chose to remain with electronic referrals when it was their turn to recruit. The mean number of enrolled referrals was 0.91 for electronic referrals compared to 0.56 for paper coupons. Median referral lag time, i.e., the time interval between when recruiters were given their referrals and when a referred individual enrolled in the study, was 20 days (IQR 10–40) for electronic referrals, 20 days (IQR 8–58) for paper coupons, 20 days (IQR 10–41) for raffle entries and 33 days (IQR 16–148) for small cash incentives. Conclusions The recruitment of MSM who travel internationally required maximizing known flexible tools of RDS while at the same time necessitating innovations to increase recruitment efficiency. Electronic referrals emerged as a major advantage in recruiting this hard-to-reach population who are of high socio-economic status, geographically diffuse and highly mobile. These enhancements may improve the performance of RDS in target populations with similar characteristics.

Gay and bisexual men engage in fewer risky sexual behaviors while traveling internationally: a cross-sectional study in San Francisco

Background International travel poses potential challenges to HIV prevention. A number of studies have observed an association between travel and behavioural disinhibition. In the present study, we assessed differences in sexual behaviour while travelling internationally and within the USA, compared with being in the home environment. Methods A probability-based sample of men who have sex with men (MSM) from the San Francisco Bay Area who had travelled internationally in the previous 12 months was recruited through an adapted respondent-driven sampling methodology (N=501). Participants completed interviewer-administered, computer-assisted surveys. Results Detailed partner-by-partner behavioural data by destination type were collected on 2925 sexual partnerships: 1028 while travelling internationally, 665 while travelling within the USA and 1232 while staying in the San Francisco Bay Area. The proportion of partnerships during international travel that involved unprotected anal intercourse (UAI) was lower compared with during domestic travel and staying locally. International travel was associated with decreased odds of receptive UAI (AOR=0.65, p=0.02) compared with staying locally and there was a trend towards decreased odds of insertive UAI (AOR=0.70, p=0.07). Conclusions MSM engaged in proportionately fewer sexual activities which present a high HIV transmission risk when travelling internationally, namely unprotected receptive and insertive anal intercourse and particularly with HIV serodiscordant partners. The lower sexual risk-taking during international travel was robust to controlling for many factors, including self-reported HIV serostatus, age, relationship status and type of partnership. These findings suggest that when travelling internationally, MSM may experience behavioural disinhibition to a lesser extent than had been described previously.

Types of social support and parental acceptance among transfemale youth and their impact on mental health, sexual debut, history of sex work and condomless anal intercourse

Transfemale youth (TFY) are an underserved and understudied population at risk for numerous poor physical and mental health outcomes, most notably HIV. Research suggests that parental acceptance and social support may serve as protective factors against HIV and other risks for TFY; however, it is unclear whether TFY receive primary social support from parents with or without parental acceptance of their gender identity. This study examines differences in parental acceptance, mental health and the HIV risk factors of history of sex work, age at sexual debut and engagement in condomless anal intercourse between TFY with two types of primary social support – non‐parental primary social support (NPPSS) and parental primary social support (PPSS).

Risk behaviors for HIV in sexual partnerships of San Francisco injection drug users

While injection drug users (IDU) in the USA are known to form sexual partnerships with IDU as well as non-IDU, scientific research is lacking regarding risk behaviors for HIV transmission within these partnerships. Such information could aid HIV-prevention efforts among IDU and could also explain the relatively low prevalence of HIV among non-IDU heterosexuals in US cities such as San Francisco. Using data from a cross-sectional sample of San Francisco IDU we estimated (1) the prevalence of IDU–IDU and IDU–non-IDU sexual partnerships, (2) the frequency of serodiscordant unprotected intercourse in IDU–IDU and IDU–non-IDU sexual partnerships, and (3) the frequency of concurrence of sexual risk and injection-related risk within IDU–IDU sexual partnerships. An estimated 68% of sexually active San Francisco IDU is in IDU–IDU partnerships. Our analysis suggests that compared to IDU–non-IDU partnerships, IDU–IDU partnerships include a greater rate of episodes of serodiscordant unprotected intercourse (incidence rate ratio: 10.2; 95% confidence interval: 2.1–50.7). In fact, our data suggest that 92% of serodiscordant sexual episodes involving IDU are attributable to IDU–IDU pairings. Unprotected intercourse and needle sharing occur concurrently in an estimated 29% of IDU–IDU partnerships. Our data suggest that HIV-transmission risk is higher within IDU–IDU partnerships than it is within IDU–non-IDU partnerships. This disparity could explain the relatively low prevalence of HIV among non-IDU heterosexuals in San Francisco. We recommend that HIV-prevention efforts among IDU continue to address sexual risk behaviors for HIV transmission in addition to injection-related risk behaviors, with emphasis on IDU–IDU partnerships.