How are transgender women acquiring HIV? Insights from phylogenetic transmission clusters in San Francisco

Exploring HIV risk behavior and sexual/gender identities among transgender women and their sexual partners in Peru using respondent-driven sampling

HIV prevalence is high among transgender women, but little is known about cisgender men who have sex with transgender women (MSTW). The objective of this study was to investigate characteristics and behavior of MSTW compared to transgender women and men who have sex with men (MSM) using a modified respondent-driven sampling design. Seed participants completed a survey and invited up to three sex partners. Forward recruitment continued in waves through the referral of sex partners. Cross-sectional data were assessed using mixed effects models. From February to July 2018, 479 participants in Lima, Peru enrolled (n = 199 transgender women, n = 196 MSTW, and n = 45 MSM). MSTW behavior and identity differed significantly from that of transgender women and MSM. MSTW primarily identified as bisexual (69%) or heterosexual (15%) and only 6% reported male partners. Insertive condomless anal intercourse was reported by 61% of MSTW; 46% did not know their HIV serostatus. Compared to MSTW without male partners, those with recent male partners were more likely to sell sex (OR 15.7, 95% CI 4.1-60.5), and report condomless receptive anal intercourse (OR 89.0, 95% CI 19.1-414.8). This evidence suggests that MSTW are a distinct population from MSM, and highlights the critical need to include MSTW in HIV research and interventions.

HIV prevalence, engagement in care, and risk behavior among trans women, San Francisco: Evidence of recent successes and remaining challenges

Background

Trans women have high HIV prevalence and lag behind 90–90-90 targets for HIV care. In San Francisco in 2017, 96% of trans women were aware of their status, 75% were on antiretroviral therapy, 88% had viral suppression. Initiatives to address gaps include peer navigators, free gender-affirming surgery, and housing. Our study updates HIV prevalence and engagement in care among trans women.

Methods

Cross-sectional community-based survey of trans women living in San Francisco sampled by respondent-driven sampling, 7/2019–2/2020 (N = 201). Eligibility was: self-identified trans women or other gender and assigned male at birth; living in San Francisco; English/Spanish-speaking; and 18 years or older.

Results

HIV prevalence was 42.3% (95%CI 35.4.-49.4) and associated with having a partner who injected drugs (adjusted odds ratio [AOR] 3.30, 95%CI 1.58–6.90), ever injected drugs (AOR 2.28, 95%CI 1.06–4.89), cost not a barrier to healthcare (AOR 2.63, 95%CI 1.02–6.67), emotional support from family (AOR 2.85, 95%CI 1.43–5.65), and Black/African-American (AOR 2.59, 95%CI 1.16–5.79). Of trans women with HIV, 92.9% were previously diagnosed, 89.9% were on ART, 91.5% reported viral suppression.

Conclusions

Trans women met 90–90–90 targets in 2020, at 93–90–92. Interventions need to reach Black/African-American trans women, trans women who inject drugs, and partners of trans women.

In Their Own Words: How Trans Women Acquired HIV Infection

Despite high HIV prevalence, the reasons trans women acquire HIV are not well understood. Trans women are often mis-classified or aggregated with men who have sex with men (MSM) in epidemiologic studies and HIV surveillance data. Trans women enrolled in the 2019/2020 National HIV Behavioral Surveillance Study in San Francisco were asked an open-ended question about how they were infected with HIV. The most common responses were "Sex with a straight cisgender man partner when the respondent identified as a trans woman" (43.0%); "Sexual assault" (13.9%); "Injection drug use (IDU)" (10.1%); "IDU or sexual contact" (7.6%) and "Sex with a partner who injected drugs" (7.6%). Sex with a cisgender man partner prior to identifying as a trans women (MSM contact) was not mentioned by any respondent. HIV prevention strategies targeting MSM will fail to reach trans women and many of their cisgender men partners.

Self-Identity, Beliefs, and Behavior Among Men Who Have Sex with Transgender Women: Implications for HIV Research and Interventions

While transgender women have been identified as a global priority population for HIV prevention and treatment, little is known about the cisgender male partners of transgender women, including their sexual behavior and HIV prevalence. Previous research has suggested that these male partners have varied identities and sexual behavior, which make identifying and engaging them in research difficult. This paper describes interviews conducted with fifteen cisgender men who reported recent sexual activity with transgender women in Lima, Peru. The purpose of this research was to explore how these men reported their identities and sexual behavior, to better understand how they would interact with HIV outreach, research, and care. The major themes were sexual orientation and identity; view of transgender partners; social ties to transgender women and other men with transgender women partners; disclosure of relationships; HIV knowledge and risk perception; and attitudes toward interventions. We found that language used to assess sexual orientation was problematic in this population, due to lack of consistency between orientation and reported behavior, and unfamiliarity with terms used to describe sexual orientation. In addition, stigma, lack of knowledge of HIV prevention methods, and fear of disclosure of sexual behavior were identified as barriers that could impact engagement in HIV research, prevention, and care. However, participants reported social relationships with both transgender women and other men who have transgender partners, presenting possible avenues for recruitment into HIV research and healthcare services.

Integrating Phylogenetic Biomarker Data and Qualitative Approaches: An example of HIV Transmission Clusters as a Sampling Frame for Semistructured Interviews and Implications for the COVID-19 Era

Mixed methods studies of human disease that combine surveillance, biomarker, and qualitative data can help elucidate what drives epidemiological trends. Viral genetic data are rarely coupled with other types of data due to legal and ethical concerns about patient privacy. We developed a novel approach to integrate phylogenetic and qualitative methods in order to better target HIV prevention efforts. The overall aim of our mixed methods study was to characterize HIV transmission clusters. We combined surveillance data with HIV genomic data to identify cases whose viruses share enough similarities to suggest a recent common source of infection or participation in linked transmission chains. Cases were recruited through a multi-phase process to obtain consent for recruitment to semi-structured interviews. Through linkage of viral genetic sequences with epidemiological data, we identified individuals in large transmission clusters, which then served as a sampling frame for the interviews. In this article, we describe the multi-phase process and the limitations and challenges encountered. Our approach contributes to the mixed methods research field by demonstrating that phylogenetic analysis and surveillance data can be harnessed to generate a sampling frame for subsequent qualitative data collection, using an explanatory sequential design. The process we developed also respected protections of patient confidentiality. The novel method we devised may offer an opportunity to implement a sampling frame that allows for the recruitment and interview of individuals in high-transmission clusters to better understand what contributes to spread of other infectious diseases, including COVID-19.

Non-B variants of HIV-1 in San Francisco, California

The HIV-1 epidemic in the US has historically been dominated by subtype B. HIV subtype diversity has not been extensively examined in most US cities to determine whether non-B variants have become established, as has been observed in many other global regions. We describe the diversity of non-B variants and present evidence of local transmission of non-B HIV in San Francisco. Viral sequences collected from patients between 2000 and 2016 were matched to the San Francisco HIV/AIDS case registry. HIV subtype was determined using COMET. Phylogenies were reconstructed using the pol region of subtypes A, C, D, G, CRF01_AE, CRF02_AG, and CRF07_BC, with reference sequences from the LANL HIV database. Associations of non-B subtypes and circulating recombinant forms (CRFs) with patient characteristics were assessed using multivariable logistic regression. Out of 11,381 sequences, 10,669 were from 7235 registry cases, of which 141 (2%) had non-B subtypes and CRFs and 72 (1%) had unique recombinant forms. CRF01_AE (0.8%) and subtype C (0.5%) were the most prevalent non-B forms. The frequency of non-B subtypes and CRFs increased in San Francisco during years 2000-2016. Out of 146 transmission events involving non-B study sequences, 18% indicated local transmission within the study population and 74% appeared to be inward migration of the virus. Compared to 7016 cases with only subtype B, 141 cases with non-B sequences were more likely to be of non-US country of birth (aOR = 11.02; p < 0.001), of Asian/Pacific-Islander race/ethnicity (aOR = 3.17; p < 0.001), and diagnosed after 2009 (aOR = 4.81; p < 0.001). Results suggest that most non-B infections were likely acquired outside the US and that local transmission of non-B forms has occurred but so far has not produced extensive transmission networks. Thus, non-B variants were not widely established in San Francisco, an observation that differs from cities worldwide with more diverse epidemics.

We Are All Women: Barriers and Facilitators to Inclusion of Transgender Women in HIV Treatment and Support Services Designed for Cisgender Women

Transgender women share more in common with cisgender women, with respect to sociocultural context and factors influencing HIV risk and outcomes, than they do with "men who have sex with men", a behavioral risk category in which they often are included. However, it is not yet clear whether both transgender and cisgender women would find integrated, all-women HIV programs and services desirable and beneficial. We Are All Women was a qualitative study conducted in the San Francisco Bay Area from April 2016 to January 2017, using a conceptual framework based on gender affirmation and trauma-informed care, to explore barriers and facilitators to inclusion of transgender women in HIV treatment and support services traditionally focused on cisgender women. Thirty-eight women (10 trans, 25 cis, and 3 "other" gender) participated in six semistructured, facilitated focus groups. In addition, five HIV care providers participated in semistructured, in-depth interviews. Both trans and cis women identified the desire for gender affirmation, a feeling of safety (specifically space without men), and potential community building within a care and healing context as powerful facilitators of an inclusive all-women care environment. At the same time, they recognized that tensions do exist between idealized visions of such an environment, deep-seated sentiments and behaviors among some cis women toward trans women, and the practical realities of creating the optimal spaces for all women. Opportunities for dialog between trans and cis women to mitigate gender-associated phobias and misperceptions are a valuable first step in creating HIV care environments that serve all women.