Decreasing HIV transmissions to African American women through interventions for men living with HIV post-incarceration: An agent-based modeling study

"What I Wish I Would've Known before My HIV Diagnosis": Qualitative Insights from Women Living with HIV to Inform HIV Prevention Strategies

In 2022, cisgender women accounted for one in five HIV diagnoses in the United States. Existing structural, social, and behavioral factors impede women's engagement with HIV prevention strategies including Pre-Exposure Prophylaxis (PrEP) access, condom usage, and uptake of HIV testing. This study explores the perspectives of women living with HIV (WLWH) about factors that may contribute to HIV acquisition and their advice for women who may benefit from HIV prevention strategies. We conducted semistructured interviews with 40 WLWH who were diagnosed on or after January 1, 2000. Interviews were conducted via Zoom and lasted 45-60 min. Interviews were professionally transcribed, coded, and analyzed to identify themes. Guided by the AIDS Risk Reduction Model, this study uses qualitative findings to describe the steps for recognizing and reducing HIV vulnerabilities. The analysis revealed three themes: (1) recognizing HIV risk for oneself and partner, (2) commiting to decreasing HIV risk, and (3) enacting HIV risk reduction strategies. After recognizing the personal and partner characteristics associated with increased HIV risk and committing to reducing that risk through self-love, relationship assertiveness, and boundary setting, women will be better prepared to enact risk reduction strategies. The four most commonly discussed strategies by WLWH included HIV testing, condom usage, PrEP, and avoiding drug use. This study highlights the importance of understanding the experiences of WLWH to inform effective HIV prevention strategies. Insights from these women emphasized the need for increased awareness, empowerment, and accessible resources to support HIV risk recognition and reduction among women.

A Review of Network Models for HIV Spread

BACKGROUND

HIV/AIDS has been a global health crisis for over 4 decades. Network models, which simulate human behavior and intervention impacts, have become an essential tool in guiding HIV prevention strategies and policies. However, no comprehensive survey of network models in HIV research has been conducted. This article fills that gap, offering a summary of past work and future directions to engage more researchers and inform policy related to eliminating HIV.

SETTING

Network models explicitly represent interactions between individuals, making them well-suited to study HIV transmission dynamics. Two primary modeling paradigms exist: a mechanistic approach from applied mathematics and a statistical approach from the social sciences. Each has distinct strengths and weaknesses, which should be understood for effective application to HIV research.

METHODS

We conducted a systematic review of network models used in HIV research, detailing the model types, populations, interventions, behaviors, datasets, and software used, while identifying potential future research directions.

RESULTS

Network models are particularly valuable for studying behaviors central to HIV transmission, such as partner selection and treatment adherence. Unlike traditional models, they focus on individual behaviors, aligning them with clinical practice. However, more accurate network data are needed for better model calibration and actionable insights.

CONCLUSIONS

This article serves as a point of reference for HIV researchers interested in applying network models and understanding their limitations. To our knowledge, this is the most comprehensive review of HIV network models to date.

Agent based modelling of blood borne viruses: a scoping review

BACKGROUND

The models that historically have been used to model infectious disease outbreaks are equation-based and statistical models. However, these models do not capture the impact of individual and social factors that affect the spread of common blood-borne viruses (BBVs) such as human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV). Agent-based modelling (ABM) is an alternative modelling approach that is gaining popularity in public health and epidemiology. As the field expands, it is important to understand how ABMs have been applied. In this context, we completed a scoping review of research that has been done on the ABM of BBVs.

METHOD

The inclusion/exclusion criteria were drafted using the idea of Population, Concept, and Context (PCC). The Preferred Reporting Item for Systematic Reviews and Meta-Analysis, an extension to scoping review (PRISMA-ScR), was employed in retrieving ABM literature that studied BBVs. Three databases (Scopus, Pubmed, and Embase) were systematically searched for article retrieval. 200 articles were retrieved from all the databases, with 10 duplicates. After removing the duplicates, 190 papers were screened for inclusion. After analysing the remaining articles, 70 were excluded during the abstract screening phase, and 32 were excluded during the full-text decision. Eighty-eight were retained for the scoping review analysis. To analyse this corpus of 88 papers, we developed a five-level taxonomy that categorised each paper based first on disease type, then transmission mechanism, then modelled population, then geographic location and finally, model outcome.

RESULTS

The result of this analysis show significant gaps in the ABM of BBV literature, particularly in the modeling of social and individual factors influencing BBV transmission.

CONCLUSION

There is a need for more comprehensive models that address various outcomes across different populations, transmission and intervention mechanisms. Although ABMs are a valuable tool for studying BBVs, further research is needed to address existing gaps and improve our understanding of individual and social factors that influence the spread and control of BBVs. This research can inform researchers, modellers, epidemiologists, and public health practitioners of the ABM research areas that need to be explored to reduce the burden of BBVs globally.

Protocol: the American Women: Assessing Risk Epidemiologically (AWARE) cohort study

BACKGROUND

While progress has been made in reducing HIV incidence rates among cisgender women, it continues to fall short of reaching the goal of ending the HIV epidemic with no new cases.

OBJECTIVE

This study aims to use innovative electronic methods (e.g., social media with community-informed advertisements) to recruit and retain a large (N = 1,800), diverse national sample of women at higher risk for HIV seroconversion who are 14 years of age and older to better understand the predictors of HIV-related sexual risk and HIV incidence within the context of a theoretically-grounded social-ecological framework.

METHODS

A US-based national longitudinal cohort study was launched among cisgender women with greater likelihood of HIV seroconversion Participants complete a survey with items related to demographics, substance use, mental health symptoms, interpersonal violence and other social factors. Biospecimens include self-collected vaginal and rectal swabs, and blood in microtainers to test for HIV, syphilis, chlamydia, gonorrhea, and trichomoniasis every 6 months for 2 years.

RESULTS

Participant recruitment began in June 2023 and baseline enrollment is scheduled to finish in July 2025.

DISCUSSION

Innovative and culturally sensitive strategies to improve access to HIV prevention and treatment services for cisgender women are vital to curb the burden of the HIV epidemic for this key population. Findings from this study will inform future research, intervention strategies, and public policies.

The Application of Systems Thinking to the Prevention and Control of Sexually Transmissible Infections among Adolescents and Adults: A Scoping Review

Systems thinking is a mechanism for making sense of complex systems that challenge linear explanations of cause-and-effect. While the prevention and control of sexually transmissible infections (STIs) has been identified as an area that may benefit from systems-level analyses, no review on the subject currently exists. The aim of this study is to conduct a scoping review to identify literature in which systems thinking has been applied to the prevention and control of STIs among adolescent and adult populations. Joanna Briggs Institute guidelines for the conduct of scoping reviews were followed. Five databases were searched for English-language studies published after 2011. A total of n = 6102 studies were screened against inclusion criteria and n = 70 were included in the review. The majority of studies (n = 34) were conducted in African nations. Few studies focused on priority sub-populations, and 93% were focused on HIV (n = 65). The most commonly applied systems thinking method was system dynamics modelling (n = 28). The review highlights areas for future research, including the need for more STI systems thinking studies focused on: (1) migrant and Indigenous populations; (2) conditions such as syphilis; and (3) innovations such as pre-exposure prophylaxis and at-home testing for HIV. The need for conceptual clarity around 'systems thinking' is also highlighted.

Agent-based model projections for reducing HIV infection among MSM: Prevention and care pathways to end the HIV epidemic in Chicago, Illinois

Our objective is to improve local decision-making for strategies to end the HIV epidemic using the newly developed Levers of HIV agent-based model (ABM). Agent-based models use computer simulations that incorporate heterogeneity in individual behaviors and interactions, allow emergence of systemic behaviors, and extrapolate into the future. The Levers of HIV model (LHM) uses Chicago neighborhood demographics, data on sex-risk behaviors and sexual networks, and data on the prevention and care cascades, to model local dynamics. It models the impact of changes in local preexposure prophylaxis (PrEP) and antiretroviral treatment (ART) (ie, levers) for meeting Illinois' goal of "Getting to Zero" (GTZ) -reducing by 90% new HIV infections among men who have sex with men (MSM) by 2030. We simulate a 15-year period (2016-2030) for 2304 distinct scenarios based on 6 levers related to HIV treatment and prevention: (1) linkage to PrEP for those testing negative, (2) linkage to ART for those living with HIV, (3) adherence to PrEP, (4) viral suppression by means of ART, (5) PrEP retention, and (6) ART retention. Using tree-based methods, we identify the best scenarios at achieving a 90% HIV infection reduction by 2030. The optimal scenario consisted of the highest levels of ART retention and PrEP adherence, next to highest levels of PrEP retention, and moderate levels of PrEP linkage, achieved 90% reduction by 2030 in 58% of simulations. We used Bayesian posterior predictive distributions based on our simulated results to determine the likelihood of attaining 90% HIV infection reduction using the most recent Chicago Department of Public Health surveillance data and found that projections of the current rate of decline (2016-2019) would not achieve the 90% (p = 0.0006) reduction target for 2030. Our results suggest that increases are needed at all steps of the PrEP cascade, combined with increases in retention in HIV care, to approach 90% reduction in new HIV diagnoses by 2030. These findings show how simulation modeling with local data can guide policy makers to identify and invest in efficient care models to achieve long-term local goals of ending the HIV epidemic.

An application of agent-based modeling to explore the impact of decreasing incarceration rates and increasing drug treatment access on sero-discordant partnerships among people who inject drugs

BACKGROUND

People who inject drugs (PWID) lag behind other key populations in HIV care continuum outcomes. The impacts of criminal justice reform and increasing drug treatment access on HIV have been underexplored.

METHODS

We developed agent-based models (ABM) of sexual partnerships among PWID and non-PWID, and injection equipment-sharing partnerships among PWID in five US cities (Baltimore, Boston, Miami, New York City, San Francisco) over 3 years. The first set of ABM projected changes in partnership discordance among PWID as a function of decreasing ZIP code-level incarceration rates. The second set projected discordance as a function of increasing ZIP code-level drug treatment access. ABM were parameterized and validated overall, and by city and PWID race/ethnicity (Black, Latino, White) using National HIV Behavioral Surveillance data, administrative ZIP code-level data, surveillance reports and prior literature. Informed by research on prisoner release and community-level HIV prevalence, reductions in incarceration rates were fixed at 5% and 30% and respectively projected to increase ZIP code-level HIV prevalence by 2% and 12%. Increases in drug treatment access were fixed at 30% and 58%.

RESULTS

In each city, a 30% reduction in ZIP code-level incarceration rates and 12% increase in ZIP code-level HIV prevalence significantly increased sero-discordance among at least one racial/ethnic group of PWID by 1-3 percentage points. A 5% reduction in incarceration rates, and 30% and 58% increases in drug treatment access, led to isolated significant changes in sero-discordance among Black and White PWID that were less than 1 percentage point.

CONCLUSION

Reductions in incarceration rates may lead to short-term increases in sero-discordant partnerships among some PWID by increasing community-level HIV prevalence. Efforts to increase HIV testing, engagement in care and community reintegration post release, should be strengthened in the wake of incarceration reform. Additional research should confirm these findings and explore the lack of widespread impacts of drug treatment in this study.

Preexposure prophylaxis strategies for African-American women affected by mass incarceration

OBJECTIVE

We aimed to determine the effectiveness of various preexposure prophylaxis (PrEP) prescription strategies for African-American women impacted by mass incarceration within an urban setting.

DESIGN

An agent-based model was utilized to evaluate prevention strategies in an efficient, ethical manner. By defining agents, their characteristics and relationships, we assessed population-level effects of PrEP on HIV incidence.

METHODS

We tested hypothetical PrEP prescription strategies within a simulation representing the African-American population of Philadelphia, Pennsylvania. Four strategies were evaluated: PrEP for women meeting CDC indicators regarding partner characteristics, PrEP for women with a recently incarcerated male partner, PrEP for women with a recently released male partner and couples-based PrEP at time of release. Interventions occurred alongside scale-up of HAART. We evaluated reductions in HIV transmissions, the number of persons on PrEP needed to avert one HIV transmission (NNT) and the resulting proportions of people on PrEP.

RESULTS

Scenarios prescribing PrEP based on criminal justice system involvement reduced HIV transmissions. The NNT ranged from 147 (couples-based scenario) to 300 (recently released scenario). The percentage of the female population covered by PrEP at any one time ranged from 0.14% (couples-based) to 10.8% (CDC-based). CDC-guideline scenarios were consistently less efficient compared to the justice-involved interventions.

CONCLUSION

Expanding PrEP for African-American women and their male partners affected by incarceration should be considered in national HIV prevention goals and correctional facilities leveraged as intervention sites. Partner characteristics in the current CDC indications may be more effective and efficient if guidelines considered criminal justice involvement.