A comparison of the effectiveness of respondent-driven and venue-based sampling for identifying undiagnosed HIV infection among cisgender men who have sex with men and transgender women in Tijuana, Mexico.

Efforts to increase HIV testing, diagnosis and care are critical to curbing HIV epidemics among cisgender men who have sex with men (MSM) and transgender women (TW) in low- and middle-income countries (LMIC). We compared the effectiveness of respondent-driven sampling (RDS) and venue-based sampling (VBS) for identifying previously undiagnosed HIV infection among MSM and TW in Tijuana, Mexico. Between March 2015 and December 2018, we conducted RDS within the social networks of MSM and TW and VBS at venues frequented by MSM and TW to socialize and meet sexual partners. Those reached by RDS/VBS who reported at least 18 years of age, anal sex with MSM or TW, and no previous HIV diagnosis were eligible for HIV testing. Of those screened following recruitment via RDS (N = 1232; 98.6% MSM; 1.3% TW), 60.8% (749/1232) were eligible for HIV testing and 97.5% (730/749) were tested for HIV infection, which led to the identification of 36 newly diagnosed HIV infections (4.9%). Of those screened following recruitment via VBS (N = 2560; 95.2% MSM; 4.6% TW), 56.5% (1446/2560) were eligible for HIV testing and 92.8% (1342/1446) were tested for HIV infection, which led to the identification of 82 newly diagnosed HIV infections (6.1%). The proportion of new HIV diagnoses did not differ by recruitment method (ratio = 0.81, 95% confidence interval: 0.55 to 1.18). Compared to those recruited via RDS, those tested following recruitment via VBS were younger, more likely to identify as gay, and more likely to identify as TW. Compared to those recruited via VBS, those newly diagnosed with HIV infection following recruitment via RDS reported higher levels of internalized stigma and were more likely to report injection drug use and a history of deportation from the United States. Despite RDS and VBS being equally effective for identifying undiagnosed HIV infection, each recruitment method reached different subgroups of MSM and TW in Tijuana. Our findings suggest that there may be benefits to using both RDS and VBS to increase the identification of previously undiagnosed HIV infection and ultimately support HIV care engagement among MSM and TW in Mexico and other similar LMIC.

Pines HA ，Semple SJ ，Magis-Rodríguez C ，Harvey-Vera A ，Strathdee SA ，Patrick R ，Rangel G ，Patterson TL ... -  《Journal of the International AIDS Society》

Stigma and Web-Based Sex Seeking Among Men Who Have Sex With Men and Transgender Women in Tijuana, Mexico: Cross-Sectional Study.

Stigma toward sexual and gender minorities is an important structural driver of HIV epidemics among men who have sex with men (MSM) and transgender women (TW) globally. Sex-seeking websites and apps are popular among MSM and TW. Interventions delivered via Web-based sex-seeking platforms may be particularly effective for engaging MSM and TW in HIV prevention and treatment services in settings with widespread stigma toward these vulnerable populations. To assess the potential utility of this approach, the objectives of our study were to determine the prevalence of Web-based sex seeking and examine the effect of factors that shape or are influenced by stigma toward sexual and gender minorities on Web-based sex seeking among MSM and TW in Tijuana, Mexico. From 2015 to 2018, 529 MSM and 32 TW were recruited through venue-based and respondent-driven sampling. Interviewer-administered surveys collected information on Web-based sex seeking (past 4 months) and factors that shape or are influenced by stigma toward sexual and gender minorities (among MSM and TW: traditional machismo, internalized stigma related to same-sex sexual behavior or gender identity, and outness related to same-sex sexual behavior or gender identity; among MSM only: sexual orientation and history of discrimination related to same-sex sexual behavior). A total of 5 separate multivariable logistic regression models were used to examine the effect of each stigma measure on Web-based sex seeking. A total of 29.4% (165/561) of our sample reported seeking sex partners on the Web. Web-based sex seeking was negatively associated with greater endorsement of traditional machismo values (adjusted odds ratio [AOR] 0.36, 95% CI 0.19 to 0.69) and greater levels of internalized stigma (AOR 0.96, 95% CI 0.94 to 0.99). Web-based sex seeking was positively associated with identifying as gay (AOR 2.13, 95% CI 1.36 to 3.33), greater outness (AOR 1.17, 95% CI 1.06 to 1.28), and a history of discrimination (AOR 1.83, 95% CI 1.08 to 3.08). Web-based sex-seeking is relatively common among MSM and TW in Tijuana, suggesting that it may be feasible to leverage Web-based sex-seeking platforms to engage these vulnerable populations in HIV prevention and treatment services. However, HIV interventions delivered through Web-based sex-seeking platforms may have limited reach among those most affected by stigma toward sexual and gender minorities (ie, those who express greater endorsement of traditional machismo values, greater levels of internalized stigma, lesser outness, and nongay identification), given that within our sample they were least likely to seek sex on the Web.

Espinosa da Silva C ，Smith LR ，Patterson TL ，Semple SJ ，Harvey-Vera A ，Nunes S ，Rangel G ，Pines HA ... -  《JMIR Public Health and Surveillance》

HIV testing among men who have sex with men in Tijuana, Mexico: a cross-sectional study.

HIV testing is critical to the delivery of comprehensive HIV prevention and care services, yet coverage of sexual minorities by HIV testing programmes remains insufficient in many low- and middle-income countries, including Mexico. The objective of this study was to identify the prevalence and correlates of HIV testing among men who have sex with men (MSM) in Tijuana, Mexico. We conducted a cross-sectional study (2012-2013) among 189 MSM recruited via respondent-driven sampling (RDS). RDS-weighted logistic regression was used to identify correlates of prior HIV testing. RDS-adjusted prevalence of prior and recent (≤ 12 months) HIV testing was 63.5% (95% CI 51.9% to 73.5%) and 36.8% (95% CI 25.4% to 46.4%), respectively. Prior HIV testing was positively associated with older age (adjusted OR (AOR)=1.09, 95% CI 1.04 to 1.15), being born in Tijuana (AOR=2.68, 95% CI 1.05 to 6.86), higher levels of education (AOR=2.65, 95% CI 1.08 to 6.53), identifying as homosexual or gay (AOR=3.73, 95% CI 1.48 to 9.42), being more 'out' about having sex with men (AOR=1.28, 95% CI:1.02 to 1.62), and a history of sexual abuse (AOR=3.24, 95% CI 1.06 to 9.86). Prior HIV testing was negatively associated with reporting more condomless anal intercourse acts (past 2 months) (AOR=0.95, 95% CI 0.92 to 0.98) and greater internalised homophobia (AOR=0.92, 95% CI 0.86 to 0.99). Our findings indicate an urgent need for expanded HIV testing services for MSM in Tijuana. Innovative, non-stigmatising, confidential HIV testing interventions targeted at young, less educated, migrant and non-gay identifying MSM may facilitate HIV testing and timely linkage to HIV care and treatment within this population.

Pines HA ，Goodman-Meza D ，Pitpitan EV ，Torres K ，Semple SJ ，Patterson TL ... -  《BMJ Open》

Prevalence of bacterial sexually transmitted infections and coinfection with HIV among men who have sex with men and transgender women in Tijuana, Mexico.

Bristow CC ，Espinosa da Silva C ，Vera AH ，Gonzalez-Fagoaga JE ，Rangel G ，Pines HA ... -  《-》

One size does not fit all: HIV prevalence and correlates of risk for men who have sex with men, transgender women in multiple cities in Papua New Guinea.

Hakim AJ ，Coy K ，Badman SG ，Willie B ，Narokobi R ，Gabuzzi J ，Pekon S ，Kupul M ，Hou P ，Aeno H ，Boli RN ，Nembari J ，Ase S ，Amos A ，Dala N ，Weikum D ，Callens S ，Kaldor JM ，Vallely AJ ，Kelly-Hanku A ，Kauntim mi tu Study Team ... -  《BMC PUBLIC HEALTH》