Viral Suppression Trajectories Destabilized After Coronavirus Disease 2019 Among US People With Human Immunodeficiency Virus: An Interrupted Time Series Analysis.

We examined changes in the proportion of people with human immunodeficiency virus (PWH) with virologic suppression (VS) in a multisite US cohort before and since the coronavirus disease 2019 (COVID-19) pandemic. Overall, prior gains in VS slowed during COVID-19, with disproportionate impacts on Black PWH and PWH who inject drugs.

"If you're strung out and female, they will take advantage of you": A qualitative study exploring drug use and substance use service experiences among women in Boston and San Francisco.

BACKGROUND: Significant disparities in substance use severity and treatment persist among women who use drugs compared to men. Thus, we explored how identifying as a woman was related to drug use and treatment experiences. METHODS: The study recruited participants for a qualitative interview study in Boston and San Francisco from January-November 2020. Self-identified women, age ≥ 18 years, with nonprescribed opioid use in the past 14 days were eligible for inclusion. The study team developed deductive codes based on intersectionality theory and inductive codes generated from transcript review, and identified themes using grounded content analysis. RESULTS: The study enrolled thirty-six participants. The median age was 46; 58 % were White, 16 % were Black, 14 % were Hispanic, and 39 % were unstably housed. Other drug use was common with 81 % reporting benzodiazepine, 50 % cocaine, and 31 % meth/amphetamine use respectively. We found that gender (i.e., identifying as a woman) intersected with drug use and sex work practices and exacerbated experiences of marginalization. Violence was ubiquitous in drug use environments. Some women reported experiences of gender-based violence in substance use service settings that perpetuated cycles of trauma and reinforced barriers to care. Substance use services that were women-led, safe, and responsive to women's needs were valued and sought after. CONCLUSION: Women reported a cycle of trauma and drug use exacerbated by oppression in substance use services settings. In addition to increasing access to gender-responsive care, our study highlights the need for greater research and examination of practices within substance use service settings that may be contributing to gender-based violence.

Socio-ecological Barriers to Viral Suppression Among Transgender Women Living with HIV in San Francisco and Los Angeles, California.

Troubling disparities in viral suppression persist among transgender (trans) women living with HIV in the US. We utilized baseline data from a randomized controlled trial of a behavioral intervention among trans women living with HIV in San Francisco and Los Angeles, to identify the socio-ecological correlates of biologically confirmed viral suppression (< 200 HIV-1 RNA copies/mL). Among 253 participants, the mean age was 43 (SD = 11), 46% identified as Black or African American and 35% were virally non-suppressed. In adjusted Poisson regression models, the following barriers to viral suppression were identified: injection drug use [adjusted risk ratio (aRR) 0.78, 95% CI 0.65-0.93, Z = - 2.64, p = 0.008], methamphetamine use (aRR 0.65, 95% CI 0.51-0.83, Z = - 3.45, p = 0.001), amphetamine use (aRR 0.62, 95% CI 0.44-0.87, Z = - 2.75, p = 0.006), homelessness (aRR 0.79, 95% CI 0.63-0.98, Z = - 2.06, p = 0.039), and sex work (aRR 0.60, 95% CI 0.41-0.86, Z = - 2.77, p = 0.009). These findings underscore the importance of interventions that address the socio-ecological barriers to viral suppression among trans women in urban settings.

RESUMEN: Persisten disparidades preocupantes en la supresión viral entre las mujeres transgénero (trans) que viven con el VIH en los EE. UU. Utilizamos datos de referencia de un ensayo controlado aleatorizado de una intervención conductual entre mujeres trans que viven con el VIH en San Francisco y Los Ángeles, para identificar los correlatos socioecológicos de la supresión viral confirmada biológicamente (< 200 copias/ml de ARN del VIH-1). Entre 253 participantes, la edad media fue de 43 años (DE = 11), el 46% se identificó como negro o afroamericano y el 35% no tenía supresión viral. En modelos de regresión de Poisson ajustados, se identificaron las siguientes barreras para la supresión viral: uso de drogas inyectables [razón de riesgo ajustada (aRR) 0,78, IC del 95% 0,65­0,93, Z = − 2,64, p = 0,008], uso de metanfetamina (aRR 0,65, IC 95% 0,51­0,83, Z = − 3,45, p = 0,001), consumo de anfetaminas (aRR 0,62, IC 95% 0,44­0,87, Z = − 2,75, p = 0,006), falta de vivienda (aRR 0,79, IC 95% 0,63­0,98, Z = − 2,06, p = 0,039), y trabajo sexual (aRR 0,60, IC 95% 0,41­0,86, Z = − 2,77, p = 0,009). Estos hallazgos subrayan la importancia de las intervenciones que abordan las barreras socioecológicas para la supresión viral entre las mujeres trans en entornos urbanos.

Mechanisms linking gender-based violence to worse HIV treatment and care outcomes among women in the United States.

OBJECTIVE: To test whether substance use mediates the associations between gender-based violence (GBV) and suboptimal adherence to antiretroviral therapy (ART), and GBV and poor engagement in care, among women living with HIV (WLHIV) in the United States (US). DESIGN: We analyzed longitudinal data collected among 1717 WLHIV in the Women's Interagency HIV Study (WIHS). METHODS: From 2013 to 2017, WLHIV completed semi-annual assessments on GBV, substance use, and HIV treatment and care. Adjusted multilevel logistic regression models were built to estimate the impact of GBV on; suboptimal (<95%) adherence and at least one missed HIV care appointment without rescheduling in the past 6 months. Mediation analyses were performed to test whether heavy drinking and illicit drug use mediated the associations between GBV and the two HIV outcomes. RESULTS: The mean age was 47 (standard deviation = 9), 5% reported experiencing GBV, 17% reported suboptimal adherence and 15% reported at least one missed appointment in the past 6 months. Women who experienced GBV had a significantly higher odds of suboptimal adherence [adjusted odds ratio (aOR) = 1.99; 95% confidence interval (CI) = 1.40-2.83] and missed appointments (aOR = 1.92, 95% CI = 1.32-2.33). Heavy drinking and illicit drug use mediated 36 and 73% of the association between GBV and suboptimal adherence and 29 and 65% of the association between GBV and missed appointments, respectively. CONCLUSIONS: Substance use is an underlying mechanism through which GBV affects outcomes along the HIV care continuum among WLHIV in the US. To optimize HIV treatment and care among women, interventions should address the combined epidemics of substance use, violence, and HIV.

Finding Sunshine on a Cloudy Day: A Positive Affect Intervention for Co-Occurring Methamphetamine Use and HIV.

Among sexual minority men (i.e., gay, bisexual, and other men who have sex with men) living with HIV, those who use methamphetamine experience profound health disparities. Affect Regulation Treatment to Enhance Methamphetamine Intervention Success (ARTEMIS) is an evidence-based, 5-session, individually delivered positive affect intervention adapted for sexual minority men living with HIV who use methamphetamine. ARTEMIS was designed to amplify the benefits of evidence-based substance use interventions such as contingency management (CM) with this high-priority population. Delivering ARTEMIS during CM has been shown to assist participants in reducing stimulant use, increasing positive affect, and achieving durable reductions in HIV viral load. We describe the theoretical underpinnings of the ARTEMIS intervention, provide details of the training and session protocols with a case example, and discuss implications for future applications in research and clinical settings.

Correlates of high phosphatidylethanol (PEth) levels and their concordance with self-reported heavy alcohol consumption among men who have sex with men who binge drink alcohol.

BACKGROUND: Heavy alcohol use, including binge drinking, is associated with high morbidity and mortality among men who have sex with men (MSM). Self-reported alcohol measures may lead to inaccurate estimates due to recall and social desirability biases. Objective alcohol biomarkers like phosphatidylethanol (PEth) can be used to corroborate self-report and could help to inform treatment approaches and research strategies for alcohol using MSM. METHODS: From 2015 to 2020, alcohol using MSM ≥18 years were enrolled in a randomized controlled trial evaluating the efficacy of naltrexone in reducing binge drinking. Using this trial's baseline data, we applied multivariable logistic regression to identify the correlates of high PEth levels (i.e., ≥87 ng/ml) and concordance between PEth levels and self-reported heavy drinking. RESULTS: Of 118 MSM, 64% had PEth levels ≥87 ng/ml and 72% had PEth levels that were concordant with self-reported heavy alcohol use. Factors significantly associated in separate models with elevated PEth levels were income ≥$60,000 (adjusted odds ratio [aOR] = 4.09; 95% CI = 1.13 to 14.82), being employed (aOR = 4.04; 95% CI = 1.45 to 11.32), episodic cannabis use (aOR = 4.63; 95% CI = 1.27 to 16.92), and any alcohol/substance use prior to or during anal intercourse (aOR = 2.52; 95% CI = 1.08 to 5.90). Living with HIV was associated with significantly lower odds of elevated PEth levels (aOR = 0.23; 95% CI = 0.09 to 0.61). Factors associated with significantly higher concordance between PEth levels and self-reported heavy alcohol use included at least weekly use of poppers (aOR = 6.41; 95% CI = 1.27 to 32.28) and polysubstance use (aOR = 2.53; 95% CI = 1.02 to 6.27). Living with HIV was associated with lower odds of concordance (aOR = 0.36; 95% CI = 0.14 to 0.97). CONCLUSIONS: PEth may enhance the detection of heavy drinking among MSM, including the identification of subpopulations that may benefit from targeted alcohol reduction interventions. However, PEth values for MSM living with HIV showed modest concordance with self-reported alcohol use and may need to be supplemented with additional biomarkers or evaluated against a different cutoff.

Impact of Multicomponent Support Strategies on Human Immunodeficiency Virus Virologic Suppression Rates During Coronavirus Disease 2019: An Interrupted Time Series Analysis.

BACKGROUND: After coronavirus disease 2019 (COVID-19) shelter-in-place (SIP) orders, viral suppression (VS) rates initially decreased within a safety-net human immunodeficiency virus (HIV) clinic in San Francisco, particularly among people living with HIV (PLWH) who are experiencing homelessness. We sought to determine if proactive outreach to provide social services, scaling up of in-person visits, and expansion of housing programs could reverse this decline. METHODS: We assessed VS 24 months before and 13 months after SIP using mixed-effects logistic regression followed by interrupted time series (ITS) analysis to examine changes in the rate of VS per month. Loss to follow-up (LTFU) was assessed via active clinic tracing. RESULTS: Data from 1816 patients were included; the median age was 51 years, 12% were female, and 14% were experiencing unstable housing/homelessness. The adjusted odds of VS increased 1.34 fold following institution of the multicomponent strategies (95% confidence interval [CI], 1.21-1.46). In the ITS analysis, the odds of VS continuously increased 1.05 fold per month over the post-intervention period (95% CI, 1.01-1.08). Among PLWH who previously experienced homelessness and successfully received housing support, the odds of VS were 1.94-fold higher (95% CI, 1.05-3.59). The 1-year LTFU rate was 2.8 per 100 person-years (95% CI, 2.2-3.5). CONCLUSIONS: The VS rate increased following institution of the multicomponent strategies, with a lower LFTU rate compared with prior years. Maintaining in-person care for underserved patients, with flexible telemedicine options, along with provision of social services and permanent expansion of housing programs, will be needed to support VS among underserved populations during the COVID-19 pandemic.

The syndemic effects of adverse mental health conditions and polysubstance use on being at risk of clinical depression among marginally housed and homeless transitional age youth living in San Francisco, California.

The objective of this study was to identify the correlates of being at risk of clinical depression and examine the role of syndemic factors among marginally housed and homeless transitional age youth (TAY). From 2017-2018, 100 TAY between the ages of 18 and 24 in San Francisco were recruited from Larkin Street Youth Services into a cross-sectional study. Participants completed surveys on mental health, substance use, and HIV risk behaviors. A syndemic score ranging from 0-3 was calculated by summing dichotomous measures of moderate or severe anxiety in the past two weeks, PTSD symptoms in the past month and polysubstance use in the past three months. We used modified Poisson regression with robust error variances to identify the correlates of being at risk of clinical depression in the past week, all primary effects measures were modeled separately. Among 100 participants, the average age was 21 (SD = 1.7), 67% were male, 38% were Multiracial, 54% identified as gay, lesbian, bisexual or pansexual, 13% were unstably housed, 50% were homeless and 23% were living with HIV. The majority (74%) were at risk of clinical depression, 51% had symptoms of moderate or severe anxiety, 80% exhibited symptoms of PTSD and 33% reported polysubstance use. After controlling for age in years, gender, race/ethnicity and sexual orientation, factors independently associated with being at risk of clinical depression were; symptoms of moderate or severe anxiety (adjusted risk ratio [aRR] = 1.62, 95% confidence interval [CI] = 1.23-2.12, P<0.001), symptoms of PTSD (aRR = 3.78, 95% CI = 1.58-9.04, P = 0.003), polysubstance use (aRR = 1.33, 95% CI = 1.06-1.68), P = 0.012), an increasing syndemic score (aRR = 1.40, 95% CI = 1.21-1.62), P<0.001), and having one, two or three syndemic factors (compared to none); (aRR = 2.68, 95% CI = 1.08-6.65, P = 0.032), (aRR = 3.24, 95% CI = 1.24-7.83, P = 0.003) and (aRR = 3.97, 95% CI = 1.65-9.52, P = 0.002), respectively. Integrated behavioral health models that treat co-occurring disorders simultaneously are needed to reduce syndemic risk among marginally housed and homeless TAY.

Mental Health Mediates the Association Between Gender-Based Violence and HIV Treatment Engagement in US Women.

BACKGROUND: Gender-based violence (GBV) is associated with poorer engagement in HIV care and treatment. However, there is a dearth of research on the psychological (eg, mental health) and structural (eg, food insecurity) factors that mediate and moderate this association. GBV could lead to poor mental health, which in turn affects adherence, whereas food insecurity could worsen the effect of GBV on engagement in care. This study uses data from the Women's Interagency HIV Study to address these gaps. METHODS: Women completed 6 assessments from 2013 to 2016 on GBV, mental health, food insecurity, adherence to antiretroviral therapy, and missed HIV care appointments in the past 6 months. Multilevel logistic regression models estimated associations between GBV and engagement in care and whether associations were mediated by depression, generalized anxiety disorder (GAD), and posttraumatic stress disorder (PTSD) and moderated by food insecurity. RESULTS: GBV was associated with higher odds of suboptimal adherence (adjusted odds ratio: 1.88; 95% confidence interval: 1.24 to 2.87) and missed appointments (adjusted odds ratio: 1.76; 95% confidence interval: 1.16 to 2.67). The association between GBV and adherence was mediated by depressive symptoms, GAD, and PTSD, accounting for 29.7%, 15.0%, and 16.5%, respectively, of the total association. The association between GBV and missed appointments was mediated by depression and GAD, but not PTSD, with corresponding figures of 25.2% and 19.7%. Associations did not differ by food insecurity. CONCLUSIONS: GBV is associated with suboptimal engagement in care, which may be explained by mental health. Interventions should address women's mental health needs, regardless of food insecurity, when improving engagement in HIV care.

Social and Behavioral Correlates of Sexually Transmitted Infections among Men who Have Sex with Men who Use Alcohol in the San Francisco Bay Area.

The risk of acquiring sexually transmitted infections (STIs) among men who have sex with men (MSM) is driven by various socio-behavioral factors. From 2015-2017, 247 MSM ≥ 18 years-old who reported alcohol use in the past year, were recruited into a cross-sectional study in San Francisco. Participants completed a survey assessing socio-demographics, substance use and treatment, sexual behaviors, HIV status and self-reported STI diagnosis in the past 6 months. Multivariable logistic regression models stratified by HIV status were used to identify the correlates of STIs. Of 247 MSM, the prevalence of bacterial STIs were: gonorrhea (12.9%), chlamydia (9.3%) and syphilis (6.0%). Among 177 MSM living without HIV, factors significantly associated with recent STI diagnosis were: current pre-exposure prophylaxis (PrEP) use (aOR = 3.53, 95% CI: 1.42-8.75, p ≤ .01), popper use during sex in the past 6 months (aOR = 3.16, 95% CI = 1.34-7.47, p ≤ .01) and a history of alcohol treatment (aOR = 0.17, 95% CI = 0.04-0.68, p = .01). Also, in a sensitivity analysis (removing PrEP), any receptive condomless anal sex was independently associated with recent STI diagnosis (aOR = 2.86, 95% CI = 1.15-7.08, p = .02). Among 70 MSM living with HIV, factors significantly associated with recent STI diagnosis were: White race/ethnicity (adjusted odds ratio [aOR] = 7.36, 95% confidence interval [CI] = 1.48-36.62, p = .01), younger age (aOR = 0.90, 95% CI: 0.84-0.97, p < .01) and a higher number of male sexual partners in the past 6 months (aOR = 1.03, 95% CI = 1.00-1.06, p = .02). Sexual health interventions that address the unique needs of MSM living with and without HIV who use alcohol in San Francisco are needed to reduce STI acquisition and transmission.

Sex differences in the multilevel determinants of injection risk behaviours among people who inject drugs in Tijuana, Mexico.

INTRODUCTION AND AIMS: HIV and hepatitis C virus transmission among people who inject drugs (PWID) is fuelled by personal and environmental factors that vary by sex. We studied PWID in Mexico to identify sex differences in multilevel determinants of injection risk. DESIGN AND METHODS: From 2011 to 2013, 734 PWID (female: 277, male: 457) were enrolled into an observational cohort study in Tijuana. Participants completed interviews on injection and sexual risks. Utilising baseline data, we conducted multiple generalised linear models stratified by sex to identify factors associated with injection risk scores (e.g. frequency of injection risk behaviours). RESULTS: For both sexes, difficult access to sterile syringes was associated with elevated injection risk (b = 1.24, 95% confidence interval [CI] 1.16-1.33), using syringes from a safe source (e.g. needle exchange programs) was associated with lower injection risk (b = 0.87, 95% CI 0.82-0.94), and for every one-unit increase in safe injection self-efficacy we observed a 20% decrease in injection risk (b = 0.80, 95% CI 0.76-0.84). Females had a higher safe injection self-efficacy score compared to males (median 2.83, interquartile range 2.2-3 vs. median 2.83, interquartile range 2-3; P = 0.01). Among females, incarceration (b = 1.22, 95% CI 1.09-1.36) and police confiscation of syringes in the past 6 months (b = 1.16, 95% CI 1.01-1.33) were associated with elevated injection risk. Among males, sex work (b = 1.16, 95% CI 1.04-1.30) and polysubstance use in the past 6 months (b = 1.22, 95% CI 1.13-1.31) were associated with elevated injection risk. DISCUSSION AND CONCLUSIONS: Interventions to reduce HIV and hepatitis C virus transmission among PWID in Tijuana should be sex-specific and consider multilevel determinants of injection risk to create safer drug use environments.

Sex Work as a Mediator Between Female Gender and Incident HIV Infection Among People Who Inject Drugs in Tijuana, Mexico.

We studied mechanisms driving gender differences in HIV incidence among 651 women and men who inject drugs (PWID) in Tijuana, Mexico, hypothesizing that sex work will mediate the association between female gender and HIV incidence. Of 43 HIV seroconversions occurring between 2011 and 2018, 8.8% were among females and 5.2% among males. HIV incidence density was significantly higher among females versus males (1.75 per 100 person years [PY], 95% CI 1.16-2.66, vs. 0.95 per 100 PY, 95% CI 0.62-1.47). Factors significantly associated with HIV seroconversion were: sex work (adjusted hazard ratio [aHR] = 2.25, 95% CI 1.05-4.80); methamphetamine injection (aHR = 2.30, 95% CI 1.12-4.73); and methamphetamine and heroin co-injection in the past six months (aHR = 2.26, 95% CI 1.23-4.15). In mediation analyses, sex work mediated a substantial proportion (84.3%) of the association between female gender and HIV incidence. Interventions should target female PWID who engage in sex work to reduce gender-related disparities in HIV incidence.

Perceived barriers to pre-exposure prophylaxis use and the role of syndemic factors among female sex workers in the Mexico-United States border region: a latent class analysis.

Female sex workers (FSWs) experience syndemic factors (e.g., polydrug use, hazardous alcohol consumption, client-perpetrated violence, depression, and sexually transmitted infections) that often heighten vulnerability to HIV and limit healthcare utilization. We hypothesized that syndemic factors will limit FSWs' uptake of pre-exposure prophylaxis (PrEP). From 2016 to 2017, 295 HIV-negative FSWs were enrolled in a behavioral HIV prevention trial in Tijuana and Ciudad Juarez, Mexico, underwent STI testing, and completed surveys on syndemic factors and perceived barriers to PrEP use. Syndemic scores (0-5) were calculated by summing syndemic factors. Latent class analysis (LCA) was used to identify homogeneous classes with respect to perceived barriers to PrEP use. We identified four classes: (1) perceived healthcare access barriers (8.3%), (2) perceived financial barriers (18.7%), (3) high level of perceived barriers (19.9%), and (4) low level of perceived barriers (53.0%) to PrEP use. Those experiencing three (adjusted odds ratio [aOR] = 3.63, 95% confidence interval [CI] = 1.24-10.67) and four or five (aOR = 6.30, 95% CI = 1.70-23.35) syndemic factors had a higher odds of membership in the class characterized by a high level of perceived barriers than in the class characterized by a low level of perceived barriers. Addressing syndemic factors may maximize PrEP's impact among FSWs along Mexico's northern border.

Randomized controlled trial of a positive affect intervention to reduce HIV viral load among sexual minority men who use methamphetamine.

INTRODUCTION: In the era of HIV treatment as prevention (TasP), evidence-based interventions that optimize viral suppression among people who use stimulants such as methamphetamine are needed to improve health outcomes and reduce onward transmission risk. We tested the efficacy of positive affect intervention delivered during community-based contingency management (CM) for reducing viral load in sexual minority men living with HIV who use methamphetamine. METHODS: Conducted in San Francisco, this Phase II randomized controlled trial tested the efficacy of a positive affect intervention for boosting and extending the effectiveness of community-based CM for stimulant abstinence to achieve more durable reductions in HIV viral load. From 2013 to 2017, 110 sexual minority men living with HIV who had biologically confirmed, recent methamphetamine use were randomized to receive a positive affect intervention (n = 55) or attention-control condition (n = 55). All individual positive affect intervention and attention-control sessions were delivered during three months of community-based CM where participants received financial incentives for stimulant abstinence. The 5-session positive affect intervention was designed to provide skills for managing stimulant withdrawal symptoms as well as sensitize individuals to natural sources of reward. The attention-control condition consisted of neutral writing exercises and self-report measures. RESULTS: Men randomized to the positive affect intervention displayed significantly lower log10 HIV viral load at six, twelve and fifteen months compared to those in the attention-control condition. Men in the positive affect intervention also had significantly lower risk of at least one unsuppressed HIV RNA (≥200 copies/mL) over the 15-month follow-up. There were concurrent, statistically significant intervention-related increases in positive affect as well as decreases in the self-reported frequency of stimulant use at six and twelve months. CONCLUSIONS: Delivering a positive affect intervention during community-based CM with sexual minority men who use methamphetamine achieved durable and clinically meaningful reductions in HIV viral load that were paralleled by increases in positive affect and decreases in stimulant use. Further clinical research is needed to determine the effectiveness of integrative, behavioural interventions for optimizing the clinical and public health benefits of TasP in sexual minority men who use stimulants such as methamphetamine.

Factors in the HIV risk environment associated with bacterial vaginosis among HIV-negative female sex workers who inject drugs in the Mexico-United States border region.

BACKGROUND: Bacterial vaginosis (BV) is the most common cause of vaginitis among women worldwide and is associated with increased susceptibility to sexually transmitted infections (STIs), including HIV. We aimed to determine the impact of the HIV risk environment on BV among female sex workers who inject drugs (FSW-PWIDs) in Tijuana and Ciudad Juarez, Mexico. METHODS: We performed a cross-sectional analysis utilizing baseline data from a randomized controlled trial evaluating a behavioral HIV prevention intervention. Participants underwent testing for BV using the OSOM BVBlue® Rapid Test (Genzyme Diagnostics, San Diego, CA) and completed a survey eliciting information on the HIV risk environment, sexual risk behaviors, and substance use. We applied logistic regression to identify correlates of BV in the physical, social, economic, and political HIV risk environments stratified by study site (Ciudad Juarez vs. Tijuana). RESULTS: In total, 584 HIV-negative FSW-PWIDs (300 Ciudad Juarez; 284 Tijuana) were enrolled. The prevalence of BV was 39% (n = 228), which was higher in Ciudad Juarez (56.7%) compared to Tijuana (20.4%). In both cities, micro-level components of the physical HIV risk environment were associated with BV. In Ciudad Juarez, BV was associated with past experiences or threats of physical violence in response to proposed condom use (adjusted odds ratio [aOR] = 3.66, 95% confidence interval [CI]: 1.74-7.69, p = 0.001) and lifetime residence in Ciudad Juarez (aOR = 1.74, 95% CI: 1.05-2.87, p = 0.031). In Tijuana, BV was associated with the number of hours spent on the street daily in the past six months looking for, using, or dealing drugs, engaging in other income generating activities, or sleeping (aOR = 1.05, 95% CI: 1.001-1.097, p = 0.045). CONCLUSIONS: Our findings suggest that FSW-PWIDs' risk of BV may be shaped by the microphysical HIV risk environment. Addressing components of the physical risk environment, including interventions to reduce gender-based violence, may alleviate the burden of BV and subsequent susceptibility to HIV/STIs among FSW-PWIDs in the Mexico/US border region. TRIAL REGISTRATION: National Institute of Health (NIH) Clinical Trials Identifier NCT00840658 , and date of NIH trial registration February 7, 2009.