Trans women face extraordinary risk for HIV, with prevalence reaching levels as high as 49.6%.1 A critical public health challenge is how to prevent new infections among adult and young trans women. Longitudinal research measuring the HIV incidence of trans women in the U.S found young age was a predictor, suggesting that current efforts are insufficient to eradicate HIV in the next generation of young trans women.2 Increasing attacks on transgender populations, particularly regarding access to gender-affirming care and HIV prevention, risk worsening existing health disparities as health access and prioritization is affected.3

Since 2000, Latin America has made important gains in expanding access to HIV prevention and treatment. Brazil is the largest country in the region and offers effective HIV prevention and care at no direct cost to users through its National Public Health System (SUS). Despite advancements, the region has seen limited progress in reducing new HIV acquisitions.4 From 2010 to 2023, the number of new HIV infections in Brazil increased by 9%. Persistent challenges in reducing new HIV acquisitions in key populations like young sexual and gender minority communities, including trans women, are part of why new infections are on the rise.4 Prior research conducted in Rio de Janeiro, Brazil found that one-third-of trans women were living with HIV, and 25% of young trans women were already living with HIV by age 24.5 Although oral Pre-Exposure Prophylaxis (PrEP) has been available in the country since 2017, only 4.5% of those currently using it are transgender people, predominantly those aged 30-years or older.6 Low PrEP utilization and poor outcomes along the PrEP continuum in Brazil7,8 highlight the urgent need to identify factors associated with new HIV infections among young trans women.

Discrimination and violence are key drivers of mental health disorders and sexual risk behaviors among trans women,5,9 contributing to HIV vulnerability through syndemic conditions such as depression, substance use, and social marginalization.10,11 Research in the US has found that experiences of bullying, trauma, mental distress and parental rejection are correlated with engagement in sexual risk behaviors and HIV status among trans youth.12 However, few studies have been conducted in Latin America with young trans women to explore their elevated vulnerability to HIV and determine factors most closely associated with risk for acquiring HIV.

In this study, we examined the correlates of new HIV diagnosis and identified factors associated with vulnerability to HIV among young trans women aged 18‒24 years in Rio de Janeiro, Brazil. The goal of this analysis was to uncover factors to target interventions tailored to young trans women to curb the ever-growing epidemic in the population and region.

Among 170 potential participants, 164 young trans women were eligible and enrolled in the study, and six were ineligible. Among those enrolled, 13% (n = 22) were living with HIV. Among these, 68% (n = 15) were unaware of their HIV status and were diagnosed with HIV at enrollment. We evaluated HIV recency in 12 out of the 15 participants with new HIV diagnosis (3 had no sample available); 33% of them (n = 4 of 12) had a recent HIV acquisition. Overall, median age was 21-years (interquartile range: 19‒22), most participants identified as Black (38%) or Pardo/mixed (26%), and 59% reported food insecurity (Table 1). Median age of identifying a gender different than assigned at birth was 13-years, while the median age of gender transition was 18-years. A large majority of participants had used Gender-Affirming Hormone Therapy (GAHT) at some point (85%), with most using non-prescribed hormones (92%). While none had undergone gender-affirming bottom surgery, 38% expressed a desire to have it in the future. A small percentage (9.8%) reported using industrial fillers (Table 2).

Prevalence of bacterial Sexually Transmitted Infections (bSTI) was high, with 23.1% presenting current active syphilis, 15% with rectal CT, and 13% with rectal NG (Table 3). No participant tested positive for hepatitis B (n = 0/163) or C (n = 0/160). A total of 70% engaged in condomless receptive anal sex in the last 6-months, and 49% ever engaged in transactional sex. Binge drinking and moderate/high risk of crack/cocaine use were reported by 74% and 9.1%, respectively. The majority of participants reported experiencing discrimination due to their gender identity (99%), with 83% having experienced verbal violence. A significant proportion screened positive for anxiety (44%), depression (32%), and PTSD (17%), and 59% reported ever attempting suicide. Furthermore, 44% reported avoiding healthcare assistance due to fear of discrimination and 32% were unaware of the meaning of ‘U = U’ (Undetectable = Untransmittable).

Compared to young trans women not living with HIV, those with a new HIV diagnosis were younger (40%vs. 25% aged 18- to 19-years). They also more frequently lived outside the main metropolitan area of Rio de Janeiro (47%vs. 23%) and had an incomplete elementary school education (33%vs. 7.8%) (Table 1). Less utilization of GAHT was observed among young trans women with a new HIV diagnosis (17%vs. 69%) and a higher proportion of industrial fillers’ use (43%vs. 20%) (Table 2). In addition, participants with a new HIV diagnosis more often reported transactional sex (66%vs. 46%), an unknown number of sexual partners (40%vs. 19%), and had lower HIV knowledge (47%vs. 23%) compared to those not living with HIV (Table 3). Regarding the ‘U = U’ message, a higher proportion of young trans women with a new HIV diagnosis were unaware of its meaning compared to those without HIV (67%vs. 30%) (Table 4). Multivariable analysis identified that individuals aged 18‒19 years (adjusted Odds Ratio [aOR=5.62], 95% Confidence Interval [95% CI 1.36‒27.22]), with lower educational attainment (aOR=7.99, 95% CI 1.78‒47.85), and those who reported moderate/high risk of crack/cocaine use (aOR=8.6, 95% CI 1.44‒54.91) had a higher odds of a new HIV diagnosis (Table 5).

More than half of young trans women living with HIV in our study were unaware of their status. Furthermore, many recently acquired HIV, suggesting ongoing incident cases that are often underestimated by prevalence studies alone.25 Young trans women also had a high burden of bSTIs. Characteristics of participants with a new HIV diagnosis were younger age, residence outside Rio de Janeiro’s metropolitan core, and the presence of intersecting vulnerabilities, including industrial filler use, engagement in sex work, and low educational attainment. The multivariable models identified educational attainment and moderate/high crack/cocaine use risk as key predictors of new HIV diagnoses, with those aged 18‒19 years old exhibiting the highest risk of a new HIV infection.

To our knowledge, this is the first study of new HIV infections among young trans women in a low- and middle-income country. Brazil is the largest country in South America, which is one of few regions globally with a rising HIV epidemic, where the highest burden falls on youth. This study points to significant unmet HIV prevention need for young trans women in Brazil. Despite high rates of prior HIV testing, many remained unaware of their status and/or not engaged in HIV prevention and care. Post-test counseling and referrals may be ineffective at linking young trans women to HIV prevention and treatment. Younger age, crack/cocaine use, and lower educational attainment were key predictors of new HIV diagnosis. These factors reflect a syndemic interplay of substance use, economic instability, and structural barriers to education, all of which exacerbate HIV vulnerability among young trans women.11,26,27 Systemic barriers, including stigma, transphobia, inadequate provider training, and limited access to gender-affirming care may further hinder engagement with HIV prevention and treatment services for young trans women.28

The association between less education and new HIV diagnoses align with broader evidence linking educational disparities to HIV vulnerability among trans populations. Other Brazilian studies have found a high percentage of low educational attainment among trans women and an association with high HIV prevalence.5,29 Low education has also been associated with low PrEP adherence in the PrEParadas study, which was a Brazilian trans-specific PrEP demonstration project.30 Lower educational attainment reduces job opportunities, creating economic insecurity and reliance on informal economies such as sex work, which was prevalent among those with a new HIV diagnosis in our sample. A large Brazilian cohort study of 22.7 million low-income individuals analyzed over 9-years (2007‒2015) found that conditional cash transfers (Bolsa Família) significantly reduced AIDS-related morbidity and mortality in highly vulnerable populations.31 In addition, among adult men who have sex with men and trans and non-binary persons living in Brazil enrolled in a cross-sectional online study advertised on dating apps and social media from May to September 2021, there was a direct link between food insecurity and non-adherence to PrEP and ART use.32

Brazil has a Universal Health System (SUS) that provides free and comprehensive healthcare to all people living in the country. SUS has played a crucial role in the HIV response by ensuring widespread access to HIV testing, prevention, and treatment, including universal access to ART and PrEP.33 Yet, many people from sexual and gender minorities face significant barriers to healthcare, including discrimination, stigma, lack of culturally competent care, and fear of mistreatment, all of which ultimately impact their health and well-being.34–36 Geographic disparities were also present in our data as many young trans women lived far from centers of affirming healthcare, reducing access to HIV prevention and care.11,37 In our sample, nearly 10% of participants with a new HIV diagnosis reported industrial filler use, a marker of engagement with unregulated cosmetic providers, a practice that is usually linked to social, medical, and economic constraints, including lack of access to transitioning procedures and healthcare avoidance.38,39 Basic HIV and sexual health education is needed among young trans women to improve their HIV knowledge and potentially reduce their sexual risk behaviors.

This study has some limitations. Due to the cross-sectional design, we cannot infer causality and temporality. The sample size also limits statistical power and the precision of estimates, particularly for subgroup analysis, and may reduce generalizability. In addition, no formal correction for multiple testing was applied, and findings should be interpreted with caution. The study was intentionally designed to enroll young trans women not yet engaged in HIV prevention or care, which may further limit generalizability to other trans populations. Despite these limitations, a key strength of the study is that it was specifically designed to reach a population that is underrepresented in research and for whom data remain scarce in our setting. As such, these findings provide valuable evidence to inform prevention and care strategies for this population.

This study reinforces that HIV disparities among young trans women are rooted in structural inequities that shape individual risk behaviors and limit access to HIV prevention and care. Tailored interventions must address the intersection of social factors and structural needs to effectively reach this population.

A complete de-identified dataset sufficient to reproduce the primary study findings will be made available upon request to the corresponding author, following approval of a concept sheet summarizing the analyses to be done.

EMJ, VGV, BG, and ECW conceived and designed the BeT study. EMJ, CC, BG, and ECW conceived and supervised the current analysis and manuscript preparation. EMJ, CC, and ECW reviewed the literature, interpreted the findings, and drafted the manuscript. CRVC and IBM were responsible for the study coordination and data acquisition. TW, CA, and LM provided important intellectual content to the study design and data interpretation. CS, NB and CC had access to raw data and verified the data. CS and NB did the statistical analyses. SLMT did the recency experiments. SLMT, RIM, SWC and BH were involved in revising the manuscript for important intellectual content. All authors read and approved the final manuscript. EMJ, CC, BG, and ECW had final responsibility for the decision to submit for publication.

This work was supported by the National Institute of Child Health and Human Development and the National Institutes of Health as the Prevention and Treatment through a Comprehensive Care Continuum for HIV-affected Adolescents in Resource Constrained Settings sponsor (grants UG3HD096914 and UH3HD096914). The sponsor had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication. BG was financed in part by CNPq (#313265/2023-2) and Carlos Chagas Filho Foundation for Research Support in the State of Rio de Janeiro (FAPERJ #E.26/200.946/2022). TST was financed in part by CNPq (#304417/2025-4 and #405558/2025-2), FAPERJ (#E-26/201.270/2022). EMJ was financed in part by FAPERJ (E-26/210.072/2025) and CNPq (408880/2025-2).