Understanding the social and structural context of oral PrEP delivery: an ethnography exploring barriers and facilitators impacting transgender women who engage in street-based sex work in Baltimore, Maryland.

Transgender women who sell sex (TWSS) experience high rates of HIV acquisition. Antiretrovirals for pre-exposure prophylaxis (PrEP) represent an efficacious HIV prevention strategy. The social and structural factors affecting PrEP delivery amongst TWSS are underexplored in the literature. We conducted ethnographic research to examine how multilevel social and structural factors manifest in TWSS's lived experiences and affect PrEP delivery and use. Twenty-four transgender women were recruited from the SAPPHIRE cohort and completed interviews focused on barriers and facilitators to PrEP engagement in the context of street-based sex work. Stakeholder interviews (N = 7) were also conducted. Our findings suggest there are unique features of the risk environment that can collectively impede PrEP use among TWSS.

Mapping Interests in Event-Driven and Long-Acting Pre-exposure Prophylaxis Formulations onto the HIV Risk Environment of Street-Based Female Sex Workers: A Latent Class Analysis.

Despite growing availability, HIV pre-exposure prophylaxis (PrEP) uptake and adherence remains suboptimal among female sex workers (FSW) in the United States. Using cross-sectional data from a survey of 236 street-based cisgender FSW in Baltimore, Maryland, we examined interest in event-driven and long-acting PrEP formulations. Latent class analysis identified discrete patterns of interest in five novel PrEP agents. Multinomial latent class regression then examined factors associated with probabilistic class membership. A three-class solution emerged as the best-fit latent class model: Injectable Acceptors (~ 24% of sample), Universal Acceptors (~ 18%), and Non-Acceptors (~ 58%). Compared to Non-Acceptors, Universal Acceptors had significantly (p < 0.05) higher odds of reporting condomless vaginal sex with clients, client condom coercion, and client-perpetrated physical violence. Relative to Non-Acceptors, Injectable Acceptors were distinguished by significantly higher rates of condomless vaginal sex with clients and injection drug use. Expanding PrEP options for FSW could help overcome barriers to PrEP initiation and persistence.

Characterising HIV and STIs among transgender female sex workers: a longitudinal analysis.

OBJECTIVES: Though highly vulnerable to HIV and STIs, transgender female sex workers (TFSWs) are understudied in the US HIV and STI response. This study examined the correlates of laboratory-confirmed STIs among a cohort of 62 TFSWs followed over the course of 1 year and explored associations between specimen site and self-reported engagement in insertive and receptive anal intercourse. METHODS: Participants completed an interviewer-administered computer-assisted personal interview at baseline, 3-, 6-, 9- and 12-month visits where self-administered anal swabs and urine samples for gonorrhea, chlamydia and trichomoniasis were also collected. HIV testing was conducted at baseline, 6-month and 12-month visits. RESULTS: Baseline HIV prevalence was 40.3% with no HIV seroconversions over follow-up. Baseline prevalence of gonorrhea, chlamydia and trichomoniasis was 9.7%, 17.7% and 14.5%, respectively. In the multivariable regression modelling, recent arrest was significantly associated with testing positive for any STI (adjusted risk ratio (RR) 1.77; 95% CI: 1.10 to 2.84). Insertive anal sex with clients was associated with increased risk of testing positive for an STI via urine specimen (RR 3.48; 95% CI: 1.14 to 10.62), while receptive anal sex was not significantly associated with specimen site. CONCLUSION: Our findings confirm a high prevalence of STIs among TFSWs and highlight the importance of addressing structural drivers such as criminal justice involvement as well as the need to ensure screening for STIs at all anatomical sites regardless of self-reported sites of potential exposure. More research is needed to better understand HIV and STI vulnerabilities and appropriate interventions for TFSWs in the USA.

The Role of Sexually Transmitted Infections in Police as Clients Among Street-Based Female Sex Workers in Baltimore City.

BACKGROUND: Research among street-based female sex workers (FSWs) has documented many harms caused by police. One harm that has received little attention is that of police as clients. We examined this interaction in a 12-month longitudinal cohort study of street-based FSWs in Baltimore, MD. METHODS: We explored longitudinal bivariate and multivariate associations between having police clients and independent variables that focused on sexually transmitted infections (STIs), as well as demographic, structural, substance use, police interaction, and violence-related factors. RESULTS: Mean participant age was 35.8 years, 65.9% were White, and more than half (53.3%) had less than a high school education. Most (70.3%) used heroin daily, and 24.8% reported having police as clients over the study period. In a multivariate model, factors independently associated with recent police clients were recent arrest (adjusted odds ratio [aOR], 1.76; 95% confidence interval [CI], 1.03-2.99; P = 0.037), coerced or forced sex by police (aOR, 4.47; 95% CI, 1.79-11.12; P = 0.001), higher number of egregious police practices experienced (aOR, 1.77; 95% CI, 1.38-2.29; P < 0.001), and prevalent STI infection (aOR, 2.43; 95% CI, 1.46-4.04; P = 0.001). CONCLUSIONS: The study uniquely documents both the frequency with which street-based FSWs take police as clients and the role of egregious police practices and prevalent STIs in association with police as clients. Results indicate the police-as-client association as a form of "everyday violence," which both normalizes and legitimizes police power and structural violence. Alongside the urgent need for decriminalization of sex work and STI prevention programs tailored for this complex population, prompt investigation and harsher penalties for police officers who engage in sex with FSW could help shift police culture away from abuse.

Exposure to Police and Client Violence Among Incarcerated Female Sex Workers in Baltimore City, Maryland.

Objectives. To determine the rate and correlates of incarceration among street-based female sex workers (FSWs).Methods. From April 2016 to January 2017, FSWs (n = 250) in Baltimore City, Maryland, were enrolled in a 12-month prospective cohort study. We analyzed baseline data and used zero-inflated negative binomial regression to model the incarceration rate.Results. Overall, 70% of FSWs had ever been incarcerated (mean = 15 times). In the multivariable analysis, incarceration rate was higher for FSWs exposed to police violence, non-Hispanic White FSWs, and women who used injection drugs daily. Risk for ever being incarcerated was higher for FSWs exposed to police or client violence, non-Hispanic Black FSWs, women who used injection or noninjection drugs daily, and those with longer time in sex work.Conclusions. Incarceration was associated with exposure to violence from both police and clients. Daily drug use and time in sex work appeared to amplify these risks. Although non-Hispanic Black women were at greater risk for ever being incarcerated, non-Hispanic White women were incarcerated more frequently.Public Health Implications. Decriminalization of sex work and drug use should be prioritized to reduce violence against FSWs.

The PrEP Care Continuum Among Cisgender Women Who Sell Sex and/or Use Drugs Globally: A Systematic Review.

HIV prevalence among cisgender female sex workers (FSW) and/or women who use drugs (WWUD) is substantially higher compared to similarly aged women. Consistent with PRISMA guidelines, we conducted the first systematic review on the pre-exposure prophylaxis (PrEP) continuum among FSW and/or WWUD, searching PubMed, Embase, CINAHL, PsycInfo, and Sociological Abstracts. Eligibility criteria included: reporting a PrEP related result among FSW and/or WWUD aged 18 + ; peer-reviewed; and published in English between 2012 and 2018. Our search identified 1365 studies; 26 met eligibility requirements, across the following groups: FSW (n = 14), WWUD (n = 9) and FSW-WWUD (n = 3). Studies report on at least one PrEP outcome: awareness (n = 12), acceptability (n = 16), uptake (n = 4), and adherence (n = 8). Specific barriers span individual and structural levels and include challenges to daily adherence, cost, and stigma. Combining health services and long-acting PrEP formulas may facilitate better PrEP uptake and adherence. The limited number of studies indicates a need for more research.

Transgender Women's Concerns and Preferences on Potential Future Long-Acting Biomedical HIV Prevention Strategies: The Case of Injections and Implanted Medication Delivery Devices (IMDDs).

There are several long-acting biomedical HIV prevention products in the development pipeline, including injections and implanted medication delivery devices (IMDDs). It is critical to understand concerns and preferences on the use of these products in populations that shoulder a disproportionate burden of the HIV epidemic, such as transgender women. This will allow researchers and public health professionals to construct interventions tailored to the needs of these women to promote optimal use of these tools. In studies of other biomedical HIV prevention products (e.g., oral PrEP) it is clear that transgender women have unique concerns related to the use of these strategies. This may have an impact on this group's uptake and sustained use of longacting HIV prevention products. This study conducted four focus groups with N = 18 transgender women in New York City to understand their concerns and preferences on long-acting PrEP injections and IMDDs. Findings showed that participants were overwhelmingly positive about long-acting HIV prevention strategies, though they had some apprehensions. Overall, participants felt that injections and IMDDs could help address adherence challenges, and that transgender-specific needs should be addressed during clinical trials. Also, there were concerns related to injection or IMDD logistics, concerns about injections' or IMDDs' presence in the body, and familiarity with these products affected participants' opinions on them. Findings from this work can be used to inform protocols, measures, materials, and adherence interventions in future initiatives for transgender women using PrEP injections or IMDDs.

Entry to Sex Trade and Long-Term Vulnerabilities of Female Sex Workers Who Enter the Sex Trade Before the Age of Eighteen.

Female sex workers are a structurally vulnerable population, including critical insecurity such as having access to food and shelter. This risk may be heightened among individuals who enter sex work as minors. However, the reasons for entering sex work as a minor and the long-term structural risk implications are poorly understood. Here, we investigated the reasons for and long-term impact of trading sex before the age of eighteen on women's structural vulnerability among a cohort of 250 cisgender women involved in street-based sex work in Baltimore City, Maryland, USA. We used logistic regression to explore the role of age of entry on two structural vulnerability outcomes of interest (homelessness and recent food insecurity in the past 3 months). Overall, 73% of women entered the sex trade to get drugs, 36% of women entered to get basic necessities such as food or housing, and 17% of women entered to support their children or family. Of significance, 21% of those aged < 18 years at entry reported being either coerced, threatened, pressured, misled, tricked, or physically forced into trading sex compared to 5% in those who entered at an older age group (p value < 0.001). In adjusted analysis, women who first trade sex before the age of 18 had 4.54 increased odds of experiencing recent homelessness (95% CI 1.92-10.70) and had 3.14 times increased odds of experiencing recent food insecurity (95% CI 1.42-6.94). Those who entered as minors were also more likely to be HIV positive (11.3% vs 3.6%, p value = 0.02). This study highlights that those who trade sex at a younger age experience an ongoing cumulative vulnerability in comparison to those entering over the age of 18. These findings call for additional research into a more detailed understanding of young women's entry into the sex trade and trajectory. A focus on the importance of policy changes and structural interventions that directly alleviate young people's socio-economic disadvantage is needed.

Barriers and facilitators to retaining a cohort of street-based cisgender female sex workers recruited in Baltimore, Maryland, USA: results from the SAPPHIRE study.

BACKGROUND: Despite experiencing HIV/STIs, violence, and other morbidities at higher rates than the general public, street-based female sex workers are often absent from public health research and surveillance due to the difficulty and high costs associated with engagement and retention. The current study builds on existing literature by examining barriers and facilitators of retaining a street-based cohort of cisgender female sex workers recruited in a mobile setting in Baltimore, Maryland who participated in the SAPPHIRE study. Participants completed interviews and sexual health testing at baseline, 3-, 6-, 9-, and 12-months. METHODS: Retention strategies are described and discussed in light of their benefits and challenges. Strategies included collecting several forms of participant contact information, maintaining an extensive field presence by data collectors, conducting social media outreach and public record searches, and providing cash and non-cash incentives. We also calculated raw and adjusted retention proportions at each follow-up period. Lastly, baseline sample characteristics were compared by number of completed visits across demographic, structural vulnerabilities, work environment, and substance use variables using F-tests and Pearson's chi-square tests. RESULTS: Although there were drawbacks to each retention strategy, each method was useful in tandem in achieving a successful follow-up rate. While direct forms of contact such as phone calls, social media outreach, and email were useful for retaining more stable participants, less stable participants required extensive field-based efforts such as home and site visits that increase the likelihood of random encounters. Overall, adjusted retention exceeded 70% for the duration of the 12-month study. Participants who were younger, recently experienced homelessness, and injected drugs daily were less likely to have completed all or most follow-up visits. CONCLUSION: Retention of street-based female sex workers required the simultaneous use of diverse retention strategies that were tailored to participant characteristics. With familiarity of the dynamic nature of the study population characteristics, resources can be appropriately allocated to strategies most likely to result in successful retention.

"An ethnographic exploration of factors that drive policing of street-based female sex workers in a U.S. setting - identifying opportunities for intervention".

BACKGROUND: Building on a broader sociological discourse around policing approaches towards vulnerable populations, increasing public health and human rights evidence points to policing practices as a key health determinant, particularly among street-based sex workers. Despite the importance of policing as a structural health determinant, few studies have sought to understand the factors that underlie and shape harmful policing practices towards sex workers. This study therefore aimed to explore the drivers for policing attitudes and practices towards street-based cisgender female sex workers. METHODS: Drawing on ethnographic methods, 280 h of observations with police patrol and 10 stakeholder interviews with senior police leadership in Baltimore City, USA were carried out to better understand the drivers for policing strategies towards cisgender female sex workers. Analysis was data- and theory-driven, drawing on the concepts of police culture and complementary criminological and sociological literature that aided exploration of the influence of the ecological and structural environment on policing practices. RESULTS: Ecological factors at the structural (e.g., criminalization), organizational (e.g., violent crime control), community and individual level (e.g., stigmatizing attitudes) emerged as key to shaping individual police practices and attitudes towards cisgender female sex workers in this setting. Findings indicate senior police support for increased alignment with public health and human rights goals. However, the study highlights that interventions need to move beyond individual officer training and address the broader structural and organizational setting in which harmful police practices towards sex work operate. CONCLUSIONS: A more in-depth understanding of the circumstances that drive law enforcement approaches to street-based sex work is critical to the collaborative design of interventions with police in different settings. In considering public health-police partnerships to address the rights and health of sex worker populations in the U.S. and elsewhere, this study supports existing calls for decriminalization of sex work, supported by institutional and policy reforms, neighborhood-level dialogues that shift the cultural landscape around sex work within both the police and larger community, and innovative individual-level police trainings.

Incidence and Predictors of Chlamydia, Gonorrhea and Trichomonas Among a Prospective Cohort of Cisgender Female Sex Workers in Baltimore, Maryland.

BACKGROUND: Cisgender female sex workers (CFSWs) have elevated rates of sexually transmitted infections (STI) yet are underrepresented in targeted programming and research in the United States. We examined the prevalence, incidence and predictors of chlamydia, gonorrhea, and trichomonas infection among CFSW. METHODS: Two hundred fifty street-based CFSWs were recruited into a prospective observational cohort in Baltimore, Maryland using targeted sampling in 2016 to 2017 and completed surveys and STI testing at baseline, 3, 6, 9, and 12 months. Cox proportional hazards regression was used to model the predictors of STI. RESULTS: Mean age was 36 years, and 66.5% of respondents were white. Baseline prevalence of chlamydia, gonorrhea, trichomonas was 10.5%, 12.6%, and 48.5%, respectively. The incidence of chlamydia, gonorrhea, and trichomonas was 14.3, 19.3, 69.1 per 100 person-years. Over one year of observation, past year sex work initiation predicted both chlamydia incidence (adjusted hazard ratio [aHR], 2.7; 95% confidence interval [CI], 1.3-6.0) and gonorrhea incidence (aHR, 1.7; 95% CI, 1.0-2.8). Client sexual violence predicted gonorrhea incidence (aHR, 2.9; 95% CI, 1.2-7.1) and having female sexual partners predicted trichomonas incidence (aHR, 3.4; 95% CI, 1.3-8.5). Having a usual health care provider (aHR, 0.6; 95% CI, 0.5-0.7) was inversely associated with trichomonas. CONCLUSIONS: In this study of urban US street-based CFSW, interpersonal and structural factors differentially predicted STIs, and infection rates remained elevated through follow-up despite regular testing, notification, and treatment referral. Focused and multifaceted interventions for sex workers and their sexual partners are urgently needed.

Police-Related Correlates of Client-Perpetrated Violence Among Female Sex Workers in Baltimore City, Maryland.

OBJECTIVES: To characterize interactions that female sex workers (FSWs) have with the police and explore associations with client-perpetrated violence. METHODS: Baseline data were collected April 2016 to January 2017 from 250 FSWs from the Sex Workers and Police Promoting Health in Risky Environments (SAPPHIRE) study based in Baltimore, Maryland. Interviewer-administered questionnaires captured different patrol or enforcement and abusive police encounters, experiences of client-perpetrated violence, and other risk factors, including drug use. We conducted bivariate and multivariable analysis in Stata/SE version 14.2 (StataCorp LP, College Station, TX). RESULTS: Of participants, 78% reported lifetime abusive police encounters, 41% reported daily or weekly encounters of any type. In the previous 3 months, 22% experienced client-perpetrated violence. Heroin users (70% of participants) reported more abusive encounters (2.5 vs 1.6; P < .001) and more client-perpetrated violence (26% vs 12%; P = .02) than others. In multivariable analysis, each additional type of abusive interaction was associated with 1.3 times (95% confidence interval [CI] = 1.1, 1.5) increased odds of client-perpetrated violence. For patrol or enforcement encounters, this value was 1.3 (95% CI = 1.0, 1.7). CONCLUSIONS: Frequent exposures to abusive police practices appear to contribute to an environment where client-perpetrated violence is regularly experienced. For FSWs who inject drugs, police exposure and client-perpetrated violence appear amplified. Public Health Implications. Structural interventions that address police-FSW interactions will help alleviate police's negative impact on FSWs' work environment.

Knowledge About Oral PrEP Among Transgender Women in New York City.

This paper grows our understanding about PrEP knowledge in transgender women (TW) to improve PrEP-focused education/outreach. Research took place in New York City. We conducted four focus groups in English or Spanish (N = 18). Discussions focused on participants' perceptions and knowledge of oral PrEP. Most participants knew that PrEP is efficacious and requires consistent use. However, some participants were skeptical of medications; others acknowledged that false assumptions about PrEP exist among TW. Most TW in our focus groups were informed about PrEP through clinics or community-based organizations. Some participants felt that messages about medications were oversimplified, and wanted more information.

Exploring new and existing PrEP modalities among female sex workers and women who inject drugs in a U.S. city.

To address a shortage in research on Pre-Exposure Prophylaxis (PrEP) amongst women at high risk of HIV acquisition, this study explored the attitudes and preferences of female sex workers (FSW) (n = 15) and women who inject drugs (WWID) (n = 16) to existing (e.g., pill) and new (e.g., injection, implant) PrEP modalities, in Baltimore, Maryland, U.S.A. This study reports on seven focus groups conducted between December 2016 and April 2017 and aims to provide new insights into FSW and WWID attitudes and preferences towards three different PrEP delivery methods (i.e., PrEP pill, PrEP implant, PrEP injection). Results draw upon the PrEP care continuum framework and distill existing factors, including lack of control over side effects with new, longer lasting modalities, better privacy with injections, increased adherence with reduced dosing schedules from longer lasting PrEP and new factors such as perceptibility concerns with respect to the PrEP implant relevant to PrEP uptake and adherence among two important overlapping, at-risk populations. The study contributes to a better understanding of barriers and facilitators to uptake and adherence for FSW and WWID around both existing and new PrEP modalities, with implications for future clinical trials and PrEP interventions with at risk-populations.

Implementing Targeted Sampling: Lessons Learned from Recruiting Female Sex Workers in Baltimore, MD.

Globally, HIV prevention interventions have proven efficacious among street-based female sex workers (FSWs); yet, there is a dearth of US-based HIV prevention research among this group. The lack of research among FSWs in the USA is partially driven by challenges in recruiting members of this population. The purpose of this research is to describe how targeted sampling was employed to recruit a cohort of street-based FSWs for a study that examined the role of police in shaping the HIV risk environments of street-based FSWs in Baltimore, MD. Our research demonstrates that targeted sampling can be an advantageous strategy for recruiting hidden populations that are mobile and geographically dispersed.

Barriers and Facilitators to Oral PrEP Use Among Transgender Women in New York City.

Transgender women may face a disparate risk for HIV/AIDS compared to other groups. In 2012, Truvada was approved for daily use as HIV pre-exposure prophylaxis (PrEP). However, there is a dearth of research about barriers and facilitators to PrEP in transgender women. This paper will shed light on transgender women living in New York City's perceived and actual challenges to using PrEP and potential strategies to overcome them. After completing an initial screening process, four 90-min focus groups were completed with n = 18 transgender women. Participants were asked what they like and dislike about PrEP. Participants identified the following barriers: uncomfortable side effects, difficulty taking pills, stigma, exclusion of transgender women in advertising, and lack of research on transgender women and PrEP. Facilitators included: reducing pill size, increasing the types of available HIV prevention products, and conducting scientific studies to evaluate PrEP in transgender women.

Structural risk and limits on agency among exotic dancers: HIV risk practices in the exotic dance club.

This paper provides longitudinal examination of women's health and sexual risk trajectories in US exotic dance clubs, which represent an important commercial setting for the economic mainstreaming of sexual services and an important target for public health programmes. Between July 2014 and May 2015, two semi-structured interviews (at baseline and at three months) were conducted with 24 female exotic dancers who had recently started working in in Baltimore City, USA. Results from a constant comparative analysis point to the interrelationship between the structures of the club setting, including the social context, and women's agentic practices concerning their sexual health. Study findings highlight the centrality of the interrelationship between individual- and structural-level experiences in influencing dancers' risk behavior. Findings point to the need for interventions to empower women both individually and collectively so as to provide the foundation for longer-term structural change.

Acceptability of Event-Driven and Long-Acting HIV Pre-Exposure Prophylaxis Formulations Among Transgender Women Engaged in Street-Based Sex Work in Baltimore, Maryland.

We assessed acceptability of nonoral HIV pre-exposure prophylaxis (PrEP) formulations among transgender women (TW) engaged in street-based sex work in Baltimore, Maryland. In a K-means cluster analysis, TW (N=36) were partitioned into groups characterized by high interest in long-acting injectable PrEP only (Injectable Enthusiasts, 36%), high interest in injectables and subdermal implants (Long-Acting Acceptors, 36%), and low interest across PrEP formulations (Non-Acceptors, 28%). TW's interest in novel PrEP agents varied widely across formulations (range: 22-66%) and clustered around numerous relational, occupational, and structural factors, highlighting the importance of availing multiple PrEP formulations for this impacted population.

The EMERALD (Enabling Mobilization, Empowerment, Risk Reduction, and Lasting Dignity) Study: Protocol for the Design, Implementation, and Evaluation of a Community-Based Combination HIV Prevention Intervention for Female Sex Workers in Baltimore, Maryland.

BACKGROUND: Cisgender female sex workers (FSWs) experience high rates of HIV and sexually transmitted infections (STIs), including chlamydia and gonorrhea. Community empowerment-based responses to the risk environment of FSWs have been associated with significant reductions in HIV and STI risk and associated risk behaviors; however, evaluations of US-based interventions targeting FSWs are limited. OBJECTIVE: The objective of this study is to describe the design, implementation, and planned evaluation strategy of an ongoing comprehensive community-level intervention in Baltimore City, Maryland, which aims to improve HIV and STI risk and cumulative incidence among FSWs. The two intervention components are the SPARC (Sex Workers Promoting Action, Risk Reduction, and Community Mobilization) drop-in center and the accompanying comprehensive mobile outreach program. The mission of SPARC is to provide low-barrier harm reduction services to FSWs, with a special focus on women who sell sex and use drugs. Services are provided through a harm reduction framework and include reproductive health and sexual health care; medication-assisted treatment; legal aid; counseling; showers, lockers, and laundry; and the distribution of harm reduction tools, including naloxone and sterile drug use supplies (eg, cookers, cotton, syringes, and pipes). METHODS: The SPARC intervention is being evaluated through the EMERALD (Enabling Mobilization, Empowerment, Risk Reduction, and Lasting Dignity) study, which consists of a prospective 2-group comparative nonrandomized trial (n=385), a cross-sectional survey (n=100), and in-depth interviews assessing SPARC implementation (n=45). Participants enrolled in the nonrandomized trial completed a survey and HIV and STI testing at 4 intervals (baseline and 6, 12, and 18 months). Participants recruited from predefined areas closest to SPARC comprised the intervention group, and participants from all other areas of Baltimore were included in the control group. RESULTS: We hypothesize that addressing structural drivers and more immediate medical needs, in combination with peer outreach, will improve the HIV and STI risk environment, leading to community empowerment, and reduce the HIV and STI cumulative incidence and behavioral risks of FSWs. Data collection is ongoing. A baseline description of the cohort is presented. CONCLUSIONS: In the United States, structural interventions aimed at reducing HIV and STIs among FSWs are scarce; to our knowledge, this is the first intervention of its kind in the United States. The results of the EMERALD study can be used to inform the development of future interventions targeting FSWs and other at-risk populations. TRIAL REGISTRATION: ClinicalTrials.gov NCT04413591; https://clinicaltrials.gov/ct2/show/NCT04413591. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/23412.