Hepatitis C virus transmission among people who inject drugs in rural United States: mathematical modeling study using stochastic agent-based network simulation

Authors

• Lin Zhu, Harvard T.H. Chan School of Public HealthFollow
• Jennifer R. Havens, University of KentuckyFollow
• Abby E. Rudolph, Temple University, Philadelphia, PA
• April M. Young, University of KentuckyFollow
• Golnaz Eftekhari Yazdi, Boston Medical Center
• William W. Thompson, Prevention Branch, Division of Viral Hepatitis, Centers for Disease Control and Prevention, Atlanta, GA
• Liesl M. Hagan, Prevention Branch, Division of Viral Hepatitis, Centers for Disease Control and Prevention, Atlanta, GA
• Liisa M. Randall, Massachusetts Department of Public Health
• Jianing Wang, Boston Medical Center
• Rebecca Earnest, Harvard T.H. Chan School of Public Health
• Shayla Nolen, Boston Medical Center
• Benjamin P. Linas, Boston Medical Center
• Joshua A. Salomon, Stanford University

Abstract

People who inject drugs (PWID) account for the majority of hepatitis C virus (HCV) infections in the United States. The injection-equipment-sharing network likely plays an important role in shaping the dynamics of HCV transmission. Recognizing the emerging HCV epidemic in rural communities, we developed an agent-based network simulation model of HCV transmission via injection equipment sharing and used data on rural PWID networks to inform model parameterization and calibration. We then simulated an array of networks that varied key network properties to understand their impact on the magnitude and distribution of HCV incidence. The results show substantial heterogeneity in HCV acquisition risks across the network, summarized using the Gini coefficient. In addition, although PWID with fewer injection partners had lower incidence, they collectively acquired more infections due to their larger population size. Higher prevalence, average number of partners, and homophily in HCV infection were associated with lower heterogeneity in infection risk across the network and higher overall incidence; other network properties including population size did not have a substantial impact. Our findings illustrate the heterogeneity of HCV transmission among PWID and suggest key network properties that could be measured, evaluated, or considered in the design of interventions for PWID in future studies.

Document Type

Article

Publication Date

2026

Notes/Citation Information

© The Author(s) 2025. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.

Digital Object Identifier (DOI)

https://doi.org/10.1093/aje/kwaf052

Funding Information

This work was supported by the US Centers for Disease Control and Prevention, National Center for HIV, Viral Hepatitis, STD, and TB Prevention Epidemiologic and Economic Modeling Agreement (U38PS004644, NU38PS004651), National Institute on Drug Abuse (K99DA056297, R37DA015612, R01DA033862, R01DA024598), and institutional funding for staff at the Massachusetts Department of Public Health.

Repository Citation

Zhu, Lin; Havens, Jennifer R.; Rudolph, Abby E.; Young, April M.; Yazdi, Golnaz Eftekhari; Thompson, William W.; Hagan, Liesl M.; Randall, Liisa M.; Wang, Jianing; Earnest, Rebecca; Nolen, Shayla; Linas, Benjamin P.; and Salomon, Joshua A., "Hepatitis C virus transmission among people who inject drugs in rural United States: mathematical modeling study using stochastic agent-based network simulation" (2026). Center on Drug and Alcohol Research Faculty Publications. 19.
https://uknowledge.uky.edu/cdar_facpub/19