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As HIV incidence among people who inject drugs grows in the context of an escalating drug overdose epidemic in North America, investigating how network structure may affect vulnerability to rapid HIV transmission is necessary for preventing outbreaks. We compared the characteristics of the observed contact tracing network from the 2015 outbreak in rural Indiana with 1000 networks generated by an agent-based network model with approximately the same number of individuals (n = 420) and ties between them (n = 913). We introduced an initial HIV infection into the simulated networks and compared the subsequent epidemic behavior (e.g., cumulative HIV infections over 5 years). The model was able to produce networks with largely comparable characteristics and total numbers of incident HIV infections. Although the model was unable to produce networks with comparable cohesiveness (where the observed network had a transitivity value 35.7 standard deviations from the mean of the simulated networks), the structural variability of the simulated networks allowed for investigation into their potential facilitation of HIV transmission. These findings emphasize the need for continued development of injection network simulation studies in tandem with empirical data collection to further investigate how network characteristics played a role in this and future outbreaks., (Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)

The purpose of this study was to examine and quantify spatial mobility among HIV-negative young men who have sex with men (YMSM) within and across high prevalence HIV neighborhoods in New York City (NYC). We completed an analysis with global positioning system (GPS) and survey data to quantify spatial mobility for participants enrolled in the P18 Neighborhood Study (analytic n = 211; 83.4%). Spatial mobility was documented with self-reported survey data and objective GPS data, which was uncorrelated. Nearly one-quarter of participants (26.1%) said that they consider the neighborhood in which they currently live to differ from the neighborhood in which they had sex most frequently. In addition, 62.9% of participants' GPS points were recorded in NYC ZIP Code Tabulation Areas within the highest quartile of HIV prevalence. Future studies of YMSM populations should be conducted to examine how environments beyond the residential neighborhood can influence sexual health, which may guide HIV prevention services., (Copyright © 2020. Published by Elsevier Ltd.)

Purpose: We assessed if young transgender women (YTW) with parents who are supportive of their transgender identity had lower odds of having suicidal ideation compared with YTW with unsupportive parents. Methods: This study analyzed baseline findings from a diverse sample of 297 sexually active, YTW 16-29 years of age who were enrolled in Project LifeSkills, a randomized controlled HIV prevention intervention efficacy trial in Chicago and Boston, between 2012 and 2015. Bivariate and multivariable logistic regression were used to assess if parental support was associated with a decreased odds of suicidal ideation. Results: Nearly one-fifth (18.9%) of YTW reported suicidal ideation at baseline. In our adjusted multivariable model, YTW with supportive mothers had 0.37 (95% confidence interval = 0.15-0.90) times the odds of having suicidal ideation compared with YTW with unsupportive mothers. Conclusion: This study found that the odds of suicidal ideation were lower among YTW who had mothers who were supportive of their transgender identity. Our results suggest that parent-focused interventions to improve the relationships between YTW and their parents may lower the odds of YTW having suicidal ideation. Clinical Trial Registration Identifier: NCT01575938.

Background: Male sex workers (MSWs) are at increased risk of HIV infection in the United States. Research is limited on sexual and drug use network characteristics of MSWs., Setting: Community-based organization and health center in 2 US Northeast cities., Methods: One hundred MSWs completed a behavioral assessment and sexual and drug network inventory. Using dyadic analyses, we assessed whether network characteristics, including sex worker-male client age, race, and HIV status homophily and risk multiplexity (ie, overlap in drug-use and sex networks), were associated with condom use., Results: MSW participants' mean age was 33.6. Two-thirds identified as Black or Latino, 12% identified as heterosexual, and 90% reported recent drug use. Participants reported an average of 5.3 male clients in the past month (SD = 3.4), and having anal sex with 74% of these clients, at a rate of 2.2 times per month (SD = 4.6). Participants reported inconsistent condom use during anal sex with 53% of clients. In multivariable models, inconsistent condom use was more common in relationships with presumed HIV status homophily [odds ratio (OR): 1.25; 95% confidence interval (CI): 1.07 to 1.46] and sexual and drug network multiplexity (OR: 1.19; 95% CI: 1.09 to 1.30); and less common within relationships where the client is older than the MSW participant (OR: 0.83; 95% CI: 0.74 to 0.93). Number of multiplex relationships was positively associated with number of condomless anal sex acts with male clients (incidence rate ratio: 1.35; 95% CI: 1.19 to 1.54)., Conclusions: Network characteristics may contribute to disproportionate HIV risk among MSWs. Modeling studies should include network characteristics when simulating HIV transmission, and future HIV interventions should address the role of networks.

Pre-exposure prophylaxis (PrEP) is an effective tool for preventing HIV infection among men who have sex with men (MSM), but its cost-effectiveness has varied across settings. Using an agent-based model, we projected the cost-effectiveness of a statewide PrEP program for MSM in Rhode Island over the next decade. In the absence of PrEP, the model predicted an average of 830 new HIV infections over ten years. Scaling up the existing PrEP program to cover 15% of MSM with ten or more partners each year could reduce the number of new HIV infections by 33.1% at a cost of $184,234 per quality-adjusted life-year (QALY) gained. Expanded PrEP use among MSM at high risk for HIV infection has the potential to prevent a large number of new HIV infections but the high drug-related costs may limit the cost-effectiveness of this intervention.

Background: Pre-exposure prophylaxis (PrEP) uptake has been slow among African American men who have sex with men (AAMSM) in the United States. We used an agent-based model (ABM) to simulate race-specific PrEP coverage to estimate their impact on racial disparities in HIV incidence among MSM in Atlanta, GA., Methods: An ABM was constructed to simulate HIV transmission in a dynamic network of 10,000 MSM over 10 years, beginning in 2015. We modeled a base scenario with estimated PrEP coverage of 2.5% among AAMSM and 5.0% among white MSM (WMSM). We then compared HIV incidence over 10 years and calculated a disparity ratio of AAMSM to WMSM incidence rates across varying PrEP scale-up scenarios, with equal and unequal coverage among AAMSM and WMSM., Results: Assuming current coverage remains constant, the model predicts HIV incidence rates of 2.95 and 1.76 per 100 person-years among AAMSM and WMSM, respectively, with a disparity ratio of 1.68. If PrEP coverage was to increase 6-fold without addressing inequities in PrEP uptake, the model predicts incidences of 2.65 and 1.34, corresponding to a mean decrease of 10.4% and 24.0% in HIV incidence, respectively. This stronger benefit for WMSM increased the disparity ratio to 1.98. Equal PrEP coverage among AAMSM and WMSM resulted in lower incidence rates overall with lower disparity ratios., Conclusions: Lower uptake among AAMSM relative to WMSM may limit the population-level impact of PrEP use among AAMSM, which may ultimately culminate in wider racial disparities in HIV incidence among MSM.