ORCID

https://orcid.org/0000-0003-1659-9508

Date of Award

Winter 2026

Language

English

Embargo Period

12-18-2025

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

College/School/Department

College of Integrated Health Sciences

Program

Epidemiology

First Advisor

Tomoko Udo

Committee Members

Eli Rosenberg, Eric Hall, Melissa Tracy

Keywords

hepatitis c, people who inject drugs, viral hepatitis, drug user health

Subject Categories

Epidemiology

Abstract

Background: Hepatitis C virus (HCV) infection is one of the leading causes of liver disease in the United States (US) and worldwide. In the United States today, HCV is transmitted primarily through injection drug use (IDU) and therefore disproportionately impacts persons who inject drugs (PWID), a population with a range of complex social and health needs. HCV is not vaccine-preventable but can be cured in over 90% of cases with an 8–12-week course of daily direct-acting antiviral (DAA) medication. Since approval of curative medications in 2014, various jurisdictions have developed plans to eliminate HCV. In 2021, the New York State (NYS) Department of Health released a plan that outlined priorities, metrics, and goals for eliminating HCV as a public health problem from the state by 2030, including a special focus on PWID. However, the baseline burden of HCV in this population, including the number of individuals with HCV, is not yet known. Understanding the burden of HCV among PWID and the demographic and risk factors associated with HCV will inform public health resource allocation, including prevention, testing, and treatment services. It may also inform data-driven interventions and investments in HCV services for PWID, to reduce disease burden in the population.

Methods: This dissertation aimed to assess the baseline burden of HCV among PWID in NYS, by estimating the number of PWID in the state (Aim 1), identifying demographic and behavioral factors associated with HCV infection (Aim 2), and modeling progress towards HCV elimination in this population given current HCV transmission and treatment dynamics (Aim 3). Aim 1 used a multiplier method anchored on nonfatal overdose emergency department visits and hospitalizations, adjusted by substance use disorder treatment admission data and data from a biobehavioral study of PWID (described in Aim 2), to estimate the number of PWID in NYS from 2019-2021. Aim 2 describes the results of a biobehavioral study that elicited a community-based sample of PWID recruited from syringe service programs (SSPs) and the surrounding community in NYS to assess HCV testing, diagnosis, and treatment history, and prevalence of HCV infection (current or past infection). This study utilized multilevel modeling to identify key demographic and risk behaviors that are associated with HCV status while controlling for clustering by SSP recruitment site. Informed by the results from Aim 1 and Aim 2, in Aim 3, I developed compartmental models of HCV transmission among PWID in NYS to assess progress towards HCV elimination targets in this population. Initial state values, and incidence, diagnosis, treatment, and reinfection rates were informed by studies of the NYS PWID population to best represent the local HCV epidemic. Results from this model were used to identify gaps and opportunities where interventions may improve achievement of elimination targets.

Results: In Aim 1, I estimated that from 2019-2021, approximately 99,206-107,705 PWID resided in NYS, representing 0.65-0.70% of the NYS 18+ population. In Aim 2, I found that 29.0% of PWID had current HCV infection, and an additional 29.0% had a previous infection, indicating that approximately 30,000 PWID in NYS were currently living with HCV infection. Risk factors for current infection included younger age, frequent injection, skin wounds and abscesses, and experiencing homelessness in the past year. Results from the models in Aim 3 indicate that prevalence of current HCV infection among PWID in NYS may decline by 2030, and treatment/clearance among the diagnosed may increase, which represents important progress towards HCV elimination targets. However, the percent of all current HCV cases that are diagnosed may decline by 2030, indicating that improving diagnosis in the PWID population is crucial for HCV elimination.

Conclusion: This dissertation comprehensively describes the current state of HCV among PWID in NYS and highlights areas where the state should enhance its effort to progress towards HCV elimination goals. These findings represent the baseline HCV burden among PWID in NYS, estimating that 29.0% of PWID in NYS, or approximately 30,000 individuals, have current HCV infection. Current HCV infection was associated with several key demographic and risk factors, including homelessness, higher injection frequency, and recent skin wounds, The findings of this dissertation will inform targeted efforts to get these PWID diagnosed, linked to care, and treated for their HCV infection. Given current incidence, diagnosis, treatment, and reinfection rates, the prevalence of current HCV infection may decrease, treatment may increase, and the percent of current HCV infections that are diagnosed may decrease by 2030. These findings will inform resource allocation and elimination initiatives to improve HCV outcomes in the NYS PWID population, particularly in improving diagnosis. Importantly, each of these three projects can be replicated with newer data to monitor changes in the PWID population size, HCV burden, and progress towards HCV elimination targets as HCV testing, diagnosis, and treatment improve among PWID in NYS over time. Continued monitoring of the burden of HCV among PWID will be crucial as we continue to progress towards HCV elimination in NYS.

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This work is licensed under the University at Albany Standard Author Agreement.

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