Author information
1Ohio State University, College of Public Health, Division of Epidemiology, United States. Electronic address: estadt.24@osu.edu.
2Ohio State University, College of Public Health, Division of Epidemiology, United States; Department of Epidemiology, University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Chapel Hill, North Carolina, United States of America.
3Wake Forest University School of Medicine, Division of Public Health Sciences, Department of Biostatistics and Data Science, United States.
4University of Washington, Department of Medicine, United States.
5University of Kentucky, Department of Epidemiology and Environmental Health, Center on Drug and Alcohol Research, United States.
6Oregon Health & Science University, Department of Medicine, Section of Addiction Medicine, United States.
7Department of Public Health and Community Medicine, Tufts University School of Medicine, United States.
8West Virginia University School of Medicine, Departments of Behavioral Medicine and Psychiatry and Medicine/Infectious Diseases, United States.
9RTI International, Research Triangle Park, NC, United States.
10University of Chicago, Department of Medicine, United States.
11University of Massachusetts Medical School-Baystate and Baystate Health, United States.
12University of Wisconsin School of Medicine and Public Health, Department of Medicine, Division of Infectious Diseases, United States.
13University of Wisconsin - Madison, School of Medicine and Public Health, Department of Family Medicine and Community Health, United States.
14Oregon Health & Science University, School of Medicine, United States.
15University of Washington, Department of Medicine, Division of Allergy and Infectious Diseases, United States.
16University of North Carolina at Chapel Hill, Gillings School of Global Public Health, Department of Health Behavior, United States.
17Ohio State University, College of Public Health, Division of Epidemiology, United States; Division of Public Health Sciences, Department of Implementation Science, Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States of America.
Abstract
Background: People who inject drugs (PWID) in the rural U.S. often inject stimulants, alone or with opioids. The impact of these substance use patterns may influence HCV risk behaviors. This analysis examines the associations of HCV antibody positivity with injecting only opioids, only stimulants (methamphetamine/cocaine), and opioids and stimulants together among rural PWID.
Methods: The Rural Opioid Initiative (ROI) consists of eight research sites that enrolled people who use drugs in rural communities in ten U.S. states from 2018 to 2020. This cross-sectional analysis included adult participants who resided in a study area and injected any drug in the past 30 days. The primary outcome was HCV antibody positivity. The exposure of interest was injection drug use classified as only opioids, only stimulants, separate injections of opioids and stimulants, and same-syringe injection of both in the past 30 days. We used multivariable log-binomial regression with generalized linear mixed models to generate prevalence ratios (P.R.) adjusted for demographics, injection history, health insurance, and substance use treatment.
Results: Among 3,084 participants enrolled in the ROI, 1,982 met inclusion criteria. Most participants injected opioids and stimulants in the same syringe (34%) or separately (21%), followed by injecting only stimulants (26%), and injecting only opioids (19%). Half (51%) were HCV antibody positive. Compared to people who injected only stimulants, HCV antibody positivity was more prevalent among people who injected opioids alone (aPR=1.62, 95% CI:(1.29-2.03)), injected both opioids and stimulants separately (aPR=1.61, 95% CI:(1.32-1.95)), and in the same syringe (aPR=1.54, 95% CI:(1.28-1.85)).
Conclusion: HCV antibody positivity, indicating prior exposure, was highest among those who had recently injected opioids, alone or with stimulants. Additional nucleic acid testing is necessary to confirm active infection. More research is needed to determine the underlying causes of HCV antibody positivity by injection use.