NEEMA Funded Projects - Cross-cutting

NEEMA 3.0 (2024-2029)

Evaluating ecologic models to identify geographic areas at risk for HIV and viral hepatitis from injection drug use

The U.S. opioid epidemic has driven increases in hepatitis C infections and stabilization of HIV infections linked to injection drug use. In 2016, CDC identified county-level indicators associated with vulnerability to HIV and HCV outbreaks among people who inject drugs, later supporting state-led vulnerability assessments. However, drug use patterns have since shifted substantially, with synthetic opioids like fentanyl now predominating, and the burden of injection drug use has nearly tripled between 2010 and 2018. Existing vulnerability assessments rely on data that are now 10 years old or older, and are largely cross-sectional, limiting their ability to capture lagged relationships between risk factors and outcomes. This project will reassess factors associated with injection drug use using more recent, longitudinal data to identify geographic areas most at risk for HIV, HCV, and other related health outcomes. It will also develop a decision-tree approach for evaluating the sensitivity and specificity of this and related vulnerability models. By updating and validating vulnerability assessment methods, this project fills a critical gap in timely, accurate data needed to prioritize prevention services and interventions. Findings will inform decision-making for federal and state agencies, public health leaders, and researchers working to prevent disease outbreaks.

Estimating the population of persons who inject drugs in U.S. States and the District of Columbia (D.C.)

Injection is a common, high-risk route of administration for opioids and other drugs, increasing risk for bloodborne infections like hepatitis C and HIV. Due to the stigmatized and illicit nature of injection drug use, population-level prevalence is difficult to measure through standard survey methods. The current national population size estimate does not reflect injection trends, limiting the ability to accurately target and evaluate infectious disease prevention efforts, as well as efforts to reduce injection drug use. This project will validate the existing national estimates of the population of persons who inject drugs (PWID) and update national prevalence estimates if new data sources improve validity. Secondly, the project will generate state-level PWID population size estimates, including for D.C. By providing validated, updated, and more granular PWID population size estimates, this project fills a critical gap in the denominators needed to assess national and state infection rates to inform resource allocation and intervention planning to prevent HIV and viral hepatitis among PWID. These estimates will also enable CDC and states to accurately compute per-population infection rates, monitor whether HIV and viral hepatitis risk is increasing or declining among the PWID population, and take appropriate public health action based on these trends.

Estimating effects of multi-infection prevention and diagnosis approaches for HIV and bacterial sexually transmitted infections among men who have sex with men

CDC recommends routine screening for syphilis, gonorrhea, and chlamydia alongside HIV testing for sexually active men who have sex with men (MSM), particularly those at higher risk or on HIV pre-exposure prophylaxis (PrEP). However, sexually transmitted infection (STI) screening is not automatically bundled with HIV testing, and screening rates remain below recommended levels, especially in non-hospital settings. This gap contributes to missed diagnoses amid rising syphilis incidence, continued evolution of drug-resistant gonorrhea, and a substantial proportion of MSM unaware of their HIV status. This project will use an agent-based microsimulation model to evaluate the potential impact of integrated HIV and bacterial STI screening among MSM under a syndemic approach. Primary objectives include estimating the epidemic impact of integrated screening and evaluating how coordinated diagnosis and treatment of HIV, syphilis, chlamydia, and gonorrhea affects infection incidence. The project will generate outputs such as infections averted per 1,000 tests to support cost-effectiveness analyses. By quantifying the benefits of integrated screening, this project fills a critical gap in evidence needed to improve testing practices and inform public health strategies to control HIV and STI transmission among MSM.

Impact of jail implementation of the CDC screening and treatment recommendations for correctional settings on national and state prevalence of hepatitis C and syphilis

People who are justice system-involved experience higher rates of hepatitis C and sexually transmitted infections than the general population, and correctional health services are often their first or only touchpoint for testing and treatment. CDC recommends comprehensive opt-out testing at intake, treatment during incarceration, and linkage to care upon release for incarcerated individuals, but staffing, budget constraints, rapid turnover of the incarcerated population, and limited collaboration with local health departments create significant barriers to full implementation. Since 95% of incarcerated individuals return to their communities, successful implementation could meaningfully reduce community disease prevalence and transmission. This project will estimate changes in national and state hepatitis C and syphilis incidence, along with associated health and economic outcomes, if all U.S. adult jails fully implemented the CDC Recommendations for Correctional Settings. Using a model incorporating national epidemiologic estimates, correctional statistics, and intervention effectiveness data, the project will evaluate scenarios reflecting varying levels of implementation and community background testing and treatment rates, along with associated costs and sensitivity analyses across the care continuum. By quantifying the potential population-level and economic benefits of full implementation, this project fills a critical gap in understanding how correctional health interventions could reduce disease transmission and disparities, informing investment and program decisions.

Impact of reducing infectious disease prevention service access and use on HIV and hepatitis C transmission in the US over time

High-impact settings such as syringe services programs serve as critical entry points to access sterile injection equipment, infectious disease testing and treatment, and navigation to substance use disorder treatment. There is a need to understand how reduced access to these services could affect health outcomes for populations at risk for HIV and hepatitis C. This project will develop a modeling framework to estimate the population health and economic impacts of hypothetical reductions in services, including sterile injection equipment, infectious disease testing and treatment, and treatment navigation. Using the model, we will evaluate how such reductions would affect HIV and HCV transmission, overdoses, healthcare expenses, and long-term health among people who inject drugs and their communities. We will also analyze differences in impact by considering local factors, such as the community's initial HIV and hepatitis C rates, current prevention and treatment efforts, and the extent and duration of service disruptions. By quantifying the potential population health and economic impacts of service reductions, this project fills a critical gap in understanding the community-level impact of infection prevention and control strategies in high-impact settings, including syringe service programs, and provides evidence to inform decision-making around community-level prevention and treatment services and efficient access points.