Fatigue Crack Growth Rates and Crack Tip Opening Loads in CT Specimens Made of SDSS and Manufactured Using WAAM.

Additive manufacturing offers greater flexibility in the design and fabrication of structural components with complex shapes. However, the use of additively manufactured parts for load-bearing structural applications, specifically involving cyclic loading, requires a thorough investigation of material fatigue properties. These properties can be affected by many factors, including residual stresses and crack tip shielding mechanisms, which can be very different from those of conventionally manufactured materials. This research focuses on super duplex stainless steels (SDSSs) fabricated with wire arc additive manufacturing (WAAM) and investigates their fatigue crack growth rates and the net effect of crack tip shielding mechanisms. Using the compliance-based method, we measured crack tip opening loads in compact tension (CT) specimens with cracks propagating longitudinally and transversely to the WAAM deposition direction. It was found that fatigue crack growth rates were very similar in both directions when correlated by the effective stress intensity factor range. However, the differences in crack tip opening loads explain a quite significant influence of the deposition direction on the fatigue life.

Impact of post-incarceration care engagement interventions on HIV transmission among young Black men who have sex with men and their sexual partners: an agent-based network modeling study.

Background: Understanding the impact of incarceration on HIV transmission among Black men who have sex with men is important given their disproportionate representation among people experiencing incarceration and the potential impact of incarceration on social and sexual networks, employment, housing, and medical care. We developed an agent-based network model (ABNM) of 10,000 agents representing young Black men who have sex with men in the city of Chicago to examine the impact of varying degrees of post-incarceration care disruption and care engagement interventions following release from jail on HIV incidence. Methods: Exponential random graph models were used to model network formation and dissolution dynamics, and network dynamics and HIV care continuum engagement were varied according to incarceration status. Hypothetical interventions to improve post-release engagement in HIV care for individuals with incarceration (e.g., enhanced case management, linkage to housing and employment services) were compared to a control scenario with no change in HIV care engagement after release. Finding: HIV incidence at 10 years was 4.98 [95% simulation interval (SI): 4.87, 5.09 per 100 person-years (py)] in the model population overall; 5.58 (95% SI 5.38, 5.76 per 100 py) among those with history of incarceration, and 12.86 (95% SI 11.89, 13.73 per 100 py) among partners of agents recently released from incarceration. Sustained post-release HIV care for agents with HIV and experiencing recent incarceration resulted in a 46% reduction in HIV incidence among post-incarceration partners [incidence rate (IR) per 100 py = 5.72 (95% SI 5.19, 6.27) vs. 10.61 (95% SI 10.09, 11.24); incidence rate ratio (IRR) = 0.54; (95% SI 0.48, 0.60)] and a 19% reduction in HIV incidence in the population overall [(IR per 100 py = 3.89 (95% SI 3.81-3.99) vs. 4.83 (95% SI 4.73, 4.92); IRR = 0.81 (95% SI 0.78, 0.83)] compared to a scenario with no change in HIV care engagement from pre-to post-release. Interpretation: Developing effective and scalable interventions to increase HIV care engagement among individuals experiencing recent incarceration and their sexual partners is needed to reduce HIV transmission among Black men who have sex with men. Funding: This work was supported by the following grants from the National Institutes of Health: R01DA039934; P20 GM 130414; P30 AI 042853; P30MH058107; T32 DA 043469; U2C DA050098 and the California HIV/AIDS Research Program: OS17-LA-003; H21PC3466.

The Integration of Value Assessment and Social Network Methods for Breast Health Navigation Among African Americans.

OBJECTIVES: A major strategy to reduce the impact of breast cancer (BC) among African Americans (AA) is patient navigation, defined here as individualized assistance for reducing barriers to healthcare use. The primary focus of this study was to estimate the added value of incorporating breast health promotion by navigated participants and the subsequent BC screenings that network members may obtain. METHODS: In this study, we compared the cost-effectiveness of navigation across 2 scenarios. First, we examine the effect of navigation on AA participants (scenario 1). Second, we examine the effect of navigation on AA participants and their networks (scenario 2). We leverage data from multiple studies in South Chicago. Our primary outcome (BC screening) is intermediate, given limited available quantitative data on the long-term benefits of BC screening for AA populations. RESULTS: When considering participant effects alone (scenario 1), the incremental cost-effectiveness ratio was $3845 per additional screening mammogram. When including participant and network effects (scenario 2), the incremental cost-effectiveness ratio was $1098 per additional screening mammogram. CONCLUSION: Our findings suggest that inclusion of network effects can contribute to a more precise, comprehensive assessment of interventions for underserved communities.

Expanding Medicaid to Reduce Human Immunodeficiency Virus Transmission in Houston, Texas: Insights From a Modeling Study.

CONTEXT: Medicaid expansion has been nationally shown to improve engagement in the human immunodeficiency virus (HIV) treatment and prevention continua, which are vital steps to stopping the HIV epidemic. New HIV infections in the United States are disproportionately concentrated among young Black men who have sex with men (YBMSM). Houston, TX, is the most populous city in the Southern United States with a racially/ethnically diverse population that is located in 1 of 11 US states that have not yet expanded Medicaid coverage as of 2021. METHODS: An agent-based model that incorporated the sexual networks of YBMSM was used to simulate improved antiretroviral treatment and pre-exposure prophylaxis (PrEP) engagement through Medicaid expansion in Houston, TX. Analyses considered the HIV incidence (number of new infections and as a rate metric) among YBMSM over the next 10 years under Medicaid expansion as the primary outcome. Additional scenarios, involving viral suppression and PrEP uptake above the projected levels achieved under Medicaid expansion, were also simulated. RESULTS: The baseline model projected an HIV incidence rate of 4.96 per 100 person years (py) and about 368 new annual HIV infections in the 10th year. Improved HIV treatment and prevention continua engagement under Medicaid expansion resulted in a 14.9% decline in the number of annual new HIV infections in the 10th year. Increasing viral suppression by an additional 15% and PrEP uptake by 30% resulted in a 44.0% decline in new HIV infections in the 10th year, and a 27.1% decline in cumulative infections across the 10 years of the simulated intervention. FINDINGS: Simulation results indicate that Medicaid expansion has the potential to reduce HIV incidence among YBMSM in Houston. Achieving HIV elimination objectives, however, might require additional effective measures to increase antiretroviral treatment and PrEP uptake beyond the projected improvements under expanded Medicaid.

Factors associated with HIV testing and treatment among young Black MSM and trans women in three jail systems.

Black men who have sex with men (BMSM) and transgender women (BTW) are disproportionately affected by incarceration and HIV. We assessed factors associated with HIV testing and viral suppression among 176 incarcerated BMSM and BTW in Chicago, IL; Los Angeles, CA; and Houston, TX. In multivariable logistic regression, having a sexual orientation of bisexual, heterosexual, or other vs. gay or same-gender loving was associated with higher odds of testing in custody (aOR 8.97; 95% CI 1.95 - 41.24). Binge drinking (aOR 0.19; 95% CI 0.04 - 0.92) and being unemployed prior to incarceration (aOR 0.03; 95% CI 0.00 - 0.23) were associated with lower odds of testing; participants in Los Angeles were also more likely to be tested than those in Chicago. Being housed in protective custody (aOR 3.12; 95% CI 1.09-9.59) and having a prescription for ART prior to incarceration (aOR 2.58; 95% CI 1.01-6.73) were associated with higher odds of viral suppression when adjusted for site and duration of incarceration, though the associations were not statistically significant in the full multivariable model. Future research should examine structural and process level factors that impact engagement in HIV testing and treatment among detained BMSM and BTW.

Community Mitigation Strategies, Mobility, and COVID-19 Incidence Across Three Waves in the United States in 2020.

BACKGROUND: Summarizing the impact of community-based mitigation strategies and mobility on COVID-19 infections throughout the pandemic is critical for informing responses and future infectious disease outbreaks. Here, we employed time-series analyses to empirically investigate the relationships between mitigation strategies and mobility on COVID-19 incident cases across US states during the first three waves of infections. METHODS: We linked data on daily COVID-19 incidence by US state from March to December 2020 with the stringency index, a well-known index capturing the strictness of mitigation strategies, and the trip ratio, which measures the ratio of the number of trips taken per day compared with the same day in 2019. We utilized multilevel models to determine the relative impacts of policy stringency and the trip ratio on COVID-19 cumulative incidence and the effective reproduction number. We stratified analyses by three waves of infections. RESULTS: Every five-point increase in the stringency index was associated with 2.89% (95% confidence interval = 1.52, 4.26%) and 5.01% (3.02, 6.95%) reductions in COVID-19 incidence for the first and third waves, respectively. Reducing the number of trips taken by 50% compared with the same time in 2019 was associated with a 16.2% (-0.07, 35.2%) decline in COVID-19 incidence at the state level during the second wave and 19.3% (2.30, 39.0%) during the third wave. CONCLUSIONS: Mitigation strategies and reductions in mobility are associated with marked health gains through the reduction of COVID-19 infections, but we estimate variable impacts depending on policy stringency and levels of adherence.

Patient Navigation Can Improve Breast Cancer Outcomes among African American Women in Chicago: Insights from a Modeling Study.

African American (AA) women experience much greater mortality due to breast cancer (BC) than non-Latino Whites (NLW). Clinical patient navigation is an evidence-based strategy used by healthcare institutions to improve AA women's breast cancer outcomes. While empirical research has demonstrated the potential effect of navigation interventions for individuals, the population-level impact of navigation on screening, diagnostic completion, and stage at diagnosis has not been assessed. An agent-based model (ABM), representing 50-74-year-old AA women and parameterized with locally sourced data from Chicago, is developed to simulate screening mammography, diagnostic resolution, and stage at diagnosis of cancer. The ABM simulated three counterfactual scenarios: (1) a control setting without any navigation that represents the "standard of care"; (2) a clinical navigation scenario, where agents receive navigation from hospital-affiliated staff; and (3) a setting with network navigation, where agents receive clinical navigation and/or social network navigation (i.e., receiving support from clinically navigated agents for breast cancer care). In the control setting, the mean population-level screening mammography rate was 46.3% (95% CI: 46.2%, 46.4%), the diagnostic completion rate was 80.2% (95% CI: 79.9%, 80.5%), and the mean early cancer diagnosis rate was 65.9% (95% CI: 65.1%, 66.7%). Simulation results suggest that network navigation may lead up to a 13% increase in screening completion rate, 7.8% increase in diagnostic resolution rate, and a 4.9% increase in early-stage diagnoses at the population-level. Results suggest that systems science methods can be useful in the adoption of clinical and network navigation policies to reduce breast cancer disparities.

Healthcare Predictors of Information Dissemination About Genetic Risks.

OBJECTIVES: Despite the benefits of genetic counseling and testing (GCT), utilization is particularly low among African American (AA) women who exhibit breast cancer features that are common in BRCA-associated cancer. Underutilization is especially problematic for AA women who are more likely to die from breast cancer than women from any other race or ethnicity. Due to medical mistrust, fear, and stigma that can be associated with genetic services among racial/ethnic minorities, reliance on trusted social networks may be an impactful strategy to increase dissemination of knowledge about hereditary cancer risk. Informed by the social cognitive theory, the purpose of this study is to determine: 1) which AA patients diagnosed with breast cancer and with identified hereditary risk are sharing information about hereditary risk with their networks; 2) the nature of the information dissemination; and 3) if personal GCT experiences is associated with dissemination of information about hereditary risk. METHODS: Among consented participants (n = 100) that completed an interview administered using a 202-item questionnaire consisting of open- and closed-ended questions, 62 patients were identified to be at higher risk for breast cancer. Descriptive statistics, bivariable chi-square, Pearson's exact tests, and regression analyses were conducted to examine differences in characteristics between high-risk participants who disseminated hereditary risk information and participants who did not. RESULTS: Among high-risk participants, 25 (40%) indicated they had disseminated information about hereditary risk to at least one member in their family/friend network and 37 (60%) had not. Receipt of both provider recommendations and receipt of GCT services was associated with greater odds of disseminating information about hereditary risk with networks, OR = 4.53, 95%CI [1.33, 15.50], p = .02. CONCLUSION: Interventions that increase self-efficacy gained through additional personalized knowledge and experience gained through provider recommendations and by undergoing GCT may facilitate information dissemination among social/familial networks.

Impact of changes in protective behaviors and out-of-household activities by age on COVID-19 transmission and hospitalization in Chicago, Illinois.

PURPOSE: Even with an efficacious vaccine, protective behaviors (social distancing, masking) are essential for preventing COVID-19 transmission and could become even more important if current or future variants evade immunity from vaccines or prior infection. METHODS: We created an agent-based model representing the Chicago population and conducted experiments to determine the effects of varying adult out-of-household activities (OOHA), school reopening, and protective behaviors across age groups on COVID-19 transmission and hospitalizations. RESULTS: From September-November 2020, decreasing adult protective behaviors and increasing adult OOHA both substantially impacted COVID-19 outcomes; school reopening had relatively little impact when adult protective behaviors and OOHA were maintained. As of November 1, 2020, a 50% reduction in young adult (age 18-40) protective behaviors resulted in increased latent infection prevalence per 100,000 from 15.93 (IQR 6.18, 36.23) to 40.06 (IQR 14.65, 85.21) and 19.87 (IQR 6.83, 46.83) to 47.74 (IQR 18.89, 118.77) with 15% and 45% school reopening. Increasing adult (age ≥18) OOHA from 65% to 80% of prepandemic levels resulted in increased latent infection prevalence per 100,000 from 35.18 (IQR 13.59, 75.00) to 69.84 (IQR 33.27, 145.89) and 38.17 (IQR 15.84, 91.16) to 80.02 (IQR 30.91, 186.63) with 15% and 45% school reopening. Similar patterns were observed for hospitalizations. CONCLUSIONS: In areas without widespread vaccination coverage, interventions to maintain adherence to protective behaviors, particularly among younger adults and in out-of-household settings, remain a priority for preventing COVID-19 transmission.

A Network Approach to Determine Optimization of PrEP Uptake in Athens, Greece.

Although the HIV epidemic in Athens, Greece has reemerged and spread in men who have sex with men (MSM), state-supported PrEP programs have not been instituted. A PrEP intervention was implemented building upon an existing network cohort of MSM (308 participants; 1212 network members). A PrEP intervention cohort of 106 participants was selected based upon sex behaviors. Individual, partner, and network characteristics were compared between the cohorts. The PrEP cohort members were more highly connected and in more influential positions in the network than their peers. Further, their sexual network connections' behaviors increased their vulnerability to HIV infection relative to the rest of the network's sex partners. This included greater stimulant use (24.2% vs 7.0%; χ2 = 28.2; p < 0.001), greater rates of at least weekly condomless sex (OR = 2.7; 95% CI 2.1-3.5; χ2 = 59.2; p < 0.001) and at least weekly use of drugs or alcohol during sex (OR = 3.4; 95% CI 2.6-4.3; χ2 = 89.7; p < 0.001). Finally the PrEP cohort's social networks showed similarly increased vulnerability to seroconversion, including greater rates of injection drug use (4.1% vs 0.5%; χ2 = 3.9; p = 0.04), greater stimulant use (33.6% vs 14.6%; χ2 = 16.9, p < 0.001), and higher rates of recent STIs (21.6% vs 13.1%; χ2 = 4.4; p = 0.04). Thus, this PrEP intervention engaged individuals in vulnerable positions with vulnerable connections within an MSM community.

Social networks, high-risk anal HPV and coinfection with HIV in young sexual minority men.

OBJECTIVES: Young sexual minority men (SMM) exhibit a high prevalence and incidence of high-risk genotypes of human papillomavirus (hrHPV) anal infections and a confluence of a high prevalence of HIV and rectal STIs. Social determinants of health (SDOHs) are linked to social network contexts that generate and maintain racial disparities in HIV and STIs. A network perspective was provided to advance our knowledge of drivers of genotype-specific hrHPV infection and coinfection with HIV. The study also examined whether socially connected men are infected with the same high-risk HPV genotypes and, if so, whether this tendency is conditioned on coinfection with HIV. METHODS: Our sample included 136 young SMM of predominantly black race and their network members of other races and ethnicities, aged 18-29 years, who resided in Houston, Texas, USA. These participants were recruited during 2014-2016 at the baseline recruitment period by network-based peer referral, where anal exfoliated cells and named social and sexual partners were collected. Exponential random graph models were estimated to assess similarity in genotype-specific hrHPV anal infection in social connections and coinfection with HIV in consideration of the effects of similarity in sociodemographic, sexual behavioural characteristics, SDOHs and syphilis infection. RESULTS: Pairs of men socially connected to each other tend to be infected with the same hrHPV genotypes of HPV-16, HPV-45 and HPV-51 or HPV-16 and/or HPV-18. The tendency of social connections between pairs of men who were infected with either HPV-16 or HPV-18 were conditioned on HIV infection. CONCLUSIONS: Networked patterns of hrHPV infection could be amenable to network-based HPV prevention interventions that engage young SMM of predominantly racial minority groups who are out of HIV care and vulnerable to high-risk HPV acquisition.

Stimulant use interventions may strengthen 'Getting to Zero' HIV elimination initiatives in Illinois: Insights from a modeling study.

OBJECTIVE(S): Getting to Zero (GTZ) is an Illinois-based HIV elimination initiative. GTZ identifies younger Black men who have sex with men (YBMSM) as a population who have experienced disproportionate HIV incidence. Rising stimulant use among YBMSM has been determined to impede engagement in the HIV prevention and treatment continua for reducing onward HIV transmission. Given the limited development of dedicated or culturally appropriate interventions for this population, this modeling study explores the impact of stimulant use on HIV incidence among YBMSM and assesses the impact of interventions to treat stimulant use on downstream HIV transmission to achieve GTZ goals. METHODS: A previously developed agent-based network model (ABNM), calibrated using data for YBMSM in Illinois, was extended to incorporate the impact of stimulant use (methamphetamines, crack/cocaine, and ecstasy) on sexual networks and engagement in HIV treatment and prevention continua. The model simulated the impact of a residential behavioral intervention (BI) for reducing stimulant use and an outpatient biomedical intervention (mirtazapine) for treating methamphetamine use. The downstream impact of these interventions on population-level HIV incidence was the primary intervention outcome. RESULTS: Baseline simulated annual HIV incidence in the ABNM was 6.93 [95% Uncertainty Interval (UI): 6.83,7.04] per 100 person years (py) and 453 [95% UI: 445.9,461.2] new infections annually. A residential rehabilitation intervention targeted to 25% of stimulant using persons yielded a 27.1% reduction in the annual number of new infections. Initiating about 50% of methamphetamine using persons on mirtazapine reduced the overall HIV incidence among YBMSM by about 11.2%. A 30% increase in antiretroviral treatment (ART) and preexposure prophylaxis (PrEP) uptake in the non-stimulant using YBMSM population combined with a 25% uptake of BI for stimulant using persons produces an HIV incidence consistent with HIV elimination targets (about 200 infections/year) identified in the GTZ initiative. CONCLUSIONS: Behavioral and biomedical interventions to treat stimulant use, in addition to expanding overall ART and PrEP uptake, are likely to enhance progress towards achieving GTZ goals.

People who inject drugs in metropolitan Chicago: A meta-analysis of data from 1997-2017 to inform interventions and computational modeling toward hepatitis C microelimination.

Progress toward hepatitis C virus (HCV) elimination in the United States is not on track to meet targets set by the World Health Organization, as the opioid crisis continues to drive both injection drug use and increasing HCV incidence. A pragmatic approach to achieving this is using a microelimination approach of focusing on high-risk populations such as people who inject drugs (PWID). Computational models are useful in understanding the complex interplay of individual, social, and structural level factors that might alter HCV incidence, prevalence, transmission, and treatment uptake to achieve HCV microelimination. However, these models need to be informed with realistic sociodemographic, risk behavior and network estimates on PWID. We conducted a meta-analysis of research studies spanning 20 years of research and interventions with PWID in metropolitan Chicago to produce parameters for a synthetic population for realistic computational models (e.g., agent-based models). We then fit an exponential random graph model (ERGM) using the network estimates from the meta-analysis in order to develop the network component of the synthetic population.

A Systematic Review up to 2018 of HIV and Associated Factors Among Criminal Justice-Involved (CJI) Black Sexual and Gender Minority Populations in the United States (US).

Black men who have sex with men (BMSM) and Black transgender women (BTW) are impacted by dual epidemics of HIV and incarceration. We advanced understanding of the relationship between criminal justice involvement, HIV, and other key HIV-related characteristics among these key populations in the US. We conducted a systematic review up to 2018 and 47 articles met the inclusion criteria of scientific publications involving quantitative findings of US-based HIV-related studies focused on criminal justice-involved (CJI) BMSM and BTW. Overall, there was a dearth of studies focused specifically on BTW. Criminal justice involvement was relatively high among BMSM and BTW and more pronounced among BTW. The current evidence favors no association between incarceration and HIV acquisition among BMSM with limited information about BTW. Criminal justice involvement was associated with a greater likelihood of STIs among BMSM with mixed results for sexual risk behaviors. Criminal justice settings served as an important venue for HIV testing/diagnosis for both BMSM and BTW. However, these settings were not conducive for subsequent stages of the HIV care continuum. Studies pointed to an independent association between criminal justice involvement, substance use, housing instability, and greater odds of incarceration among BMSM who were unemployed and had limited education. Future incarceration was associated with high levels of perceived racism among BMSM. Among young BMSM, high network criminal justice prevalence was also associated with sexual risk behaviors, poorer mental health outcomes, drug use, and housing instability. CJI BMSM and BTW represent a critical subpopulation to end the HIV epidemic in the US.

Navigated African American breast cancer patients as incidental change agents in their family/friend networks.

BACKGROUND: Patient navigation is an increasingly widespread intervention to address the persistent, severe, and disproportionate breast cancer (BC) burden that African Americans (AA) face. Navigation may have more widespread effects than previously estimated due to patient-driven diffusion of BC information. METHODS: This pilot study examined the network effects of a randomized controlled trial via recruitment of navigated and non-navigated AA BC patients as well as their network members. We estimated study arm differences in patient BC promotion (i.e., number of individuals to whom BC patients promote BC screening) and network BC screening (i.e., % BC screening among network members). RESULTS: Among our sample of 100 AA BC patients, navigated patients promoted BC screening to more individuals than non-navigated patients. BC patients were more likely to promote BC screening to children and individuals with whom they communicated more frequently. Some models further suggested more network BC screening among "navigated" network members relative to "non-navigated" network members. CONCLUSIONS: Navigated AA patients promoted BC screening more widely throughout their networks than non-navigated AA BC patients. There were also suggestive findings regarding increased BC screening among their network members. Our pilot study highlights the potential for social network analysis to improve the precision of intervention effect estimates and to inform future innovations (e.g., integrating navigation and network-based interventions) with multilevel effects on cancer health disparities.

Do partner services linked to molecular clusters yield people with viremia or new HIV?

OBJECTIVES: We examined whether molecular cluster membership was associated with public health identification of HIV transmission potential among named partners in Chicago. DESIGN: Historical cohort study. METHODS: We matched and analyzed HIV surveillance and partner services data from HIV diagnoses (2012-2016) prior to implementation of cluster detection and response interventions. We constructed molecular clusters using HIV-TRACE at a pairwise genetic distance threshold of 0.5% and identified clusters exhibiting recent and rapid growth according to the Centers for Disease Control and Prevention definition (three new cases diagnosed in past year). Factors associated with identification of partners with HIV transmission potential were examined using multivariable Poisson regression. RESULTS: There were 5208 newly diagnosed index clients over this time period. Average age of index clients in clusters was 28; 47% were Black, 29% Latinx/Hispanic, 6% female and 89% MSM. Of the 537 named partners, 191 (35.6%) were linked to index cases in a cluster and of those 16% were either new diagnoses or viremic. There was no statistically significant difference in the probability of identifying partners with HIV transmission potential among index clients in a rapidly growing cluster versus those not in a cluster [adjusted relative risk 1.82, (0.81-4.06)]. CONCLUSION: Partner services that were initiated from index clients in a molecular cluster yielded similar new HIV case finding or identification of those with viremia as did interviews with index clients not in clusters. It remains unclear whether these findings are due to temporal disconnects between diagnoses and cluster identification, unobserved cluster members, or challenges with partner services implementation.

Projecting the number of new HIV infections to formulate the "Getting to Zero" strategy in Illinois, USA.

OBJECTIVES: Getting to Zero (GTZ) initiatives focus on expanding use of antiretroviral treatment (ART) and pre-exposure prophylaxis (PrEP) to eliminate new HIV infections. Computational models help inform policies for implementation of ART and PrEP continuums. Such models, however, vary in their design, and may yield inconsistent predictions. Using multiple approaches can help assess the consistency in results obtained from varied modeling frameworks, and can inform optimal implementation strategies. METHODS: A study using three different modeling approaches is conducted. Two approaches use statistical time series analysis techniques that incorporate temporal HIV incidence data. A third approach uses stochastic stimulation, conducted using an agent-based network model (ABNM). All three approaches are used to project HIV incidence among a key population, young Black MSM (YBMSM), over the course of the GTZ implementation period (2016-2030). RESULTS: All three approaches suggest that simultaneously increasing PrEP and ART uptake is likely to be more effective than increasing only one, but increasing ART and PrEP by 20% points may not eliminate new HIV infections among YBMSM. The results further suggest that a 20% increase in ART is likely to be more effective than a 20% increase in PrEP. All three methods consistently project that increasing ART and PrEP by 30% simultaneously can help reach GTZ goals. CONCLUSIONS: Increasing PrEP and ART uptake by about 30% might be necessary to accomplish GTZ goals. Such scale-up may require addressing psychosocial and structural barriers to engagement in HIV and PrEP care continuums. ABNMs and other flexible modeling approaches can be extended to examine specific interventions that address these barriers and may provide important data to guide the successful intervention implementation.

Understanding the relationship between positive and negative social support and the quality of life among African American breast cancer survivors.

PURPOSE: Social support improves several quality of life (QOL) domains among African American breast cancer survivors. How different dimensions of social support are associated with QOL among African American breast cancer survivors may however differ from other populations. This study explores this hypothesis by examining associations of positive social support (supportive interactions that promote affection) and negative social support (non-supportive interactions wherein the provider of support may not have the best intended actions) with QOL among Chicago-based African American breast cancer survivors. METHODS: Study participants were eligible if they (1) were identified as being an African American female, (2) were at least 18 years of age or older, and (3) were diagnosed with breast cancer during or after navigation was implemented at the study hospital. Participants completed validated questionnaires via telephone or in-person interviews. RESULTS: Among our sample of 100 participants, positive support was associated with greater mental well-being in non-imputed (Std ß=1.60, CI: 0.51, 2.69, p= 0.004) and imputed models (Std ß= 1.67, CI: 0.68, 2.73, p=0.001). There was also a weaker inverse association with negative support and mental well-being when using non-imputed data (Std ß=-0.82, CI:-1.65, 0.02, p= 0.05). CONCLUSIONS: Our findings suggest that positive support, in particular, is highly influential for improving mental well-being among African American breast cancer survivors. Simultaneously, negative support appears to be an independent, albeit weaker, determinant of mental well-being.

Sexual Mixing and HIV Transmission Potential Among Greek Men Who have Sex with Men: Results from SOPHOCLES.

HIV incidence among men who have sex with men (MSM) in Greece remains unchanged despite effective response to a recent outbreak among people who inject drugs (PWID). Network factors are increasingly understood to drive transmission in epidemics. The primary objective of the study was to characterize MSM in Greece, their sexual behaviors, and sexual network mixing patterns. We investigated the relationship between serostatus, sexual behaviors, and self-reported sex networks in a sample of MSM in Athens, Greece, generated using respondent driven sampling. We estimated mixing coefficients (r) based on survey-generated egonets. Additionally, multiple logistic regression was used to estimate adjusted odds ratios (AOR) and to assess relationships between serostatus, sexual behaviors, and sociodemographic indicators. A sample of 1,520 MSM participants included study respondents (n = 308) and their network members (n = 1,212). Mixing based on serostatus (r = 0.12, σr = 0.09-0.15) and condomless sex (r = 0.11, σr = 0.07-0.14) was random. However, mixing based on sex-drug use was highly assortative (r = 0.37, σr = 0.32-0.42). This study represents the first analysis of Greek MSM sexual networks. Our findings highlight protective behavior in two distinct network typologies. The first typology mixed assortatively based on serostatus and sex-drug use and was less likely to engage in condomless sex. The second typology mixed randomly based on condomless sex but was less likely to engage in sex-drug use. These findings support the potential benefit of HIV prevention program scale-up for this population including but not limited to PrEP.

A Pragmatic Randomized Controlled Trial to Increase PrEP Uptake for HIV Prevention: 55-Week Results From PrEPChicago.

OBJECTIVES: We tested preliminary efficacy of a peer change agent type I network intervention to increase pre-exposure prophylaxis (PrEP) linkage to care among network members connected to young Black men who have sex with men. DESIGN: Parent study is a pragmatic randomized controlled trial with 110 weeks of total follow-up. Interim midpoint analyses are performed here using participant data before crossover assignment at 55 weeks. METHODS: We randomly assigned 423 participants in Chicago to receive the network intervention, an opinion leader workshop with telephonic booster sessions, versus a time-matched control from 2016 to 2018. The consolidated surrogate outcome was PrEP referral and linkage to clinical care among network members connected to study participants and was collected from independent administrative data. RESULTS: Each study participant in the trial (n = 423) had on average 1822 network contacts who could be eligible for PrEP referral and linkage. During the 55-week observation period, PrEP referral was most likely to occur within 3 days of an intervention session compared to control [odds ratio (OR) 0.07 (0.02-0.013); P = 0.007] resulting in 1-2 referrals of network members per session. Network members with referral or linkage were more likely to be connected to study participants in the intervention arm than the control condition [aOR 1.50 (1.09-2.06); P = 0.012]. CONCLUSIONS: A peer change agent type I network intervention is preliminarily effective at diffusing PrEP through a network of individuals highly susceptible to HIV over 55 weeks. This low-intensity intervention demonstrated network-level impact among populations that have experienced limited PrEP care engagement in the United States.