Social Network Factors Associated with Hepatitis C Infection among Rural Appalachian Prescription Opioid Injectors

Objective: The objective of this study was to determine the independent effect of social network factors on HCV infection among rural Appalachian prescription opioid injectors. Methods: Data from 394 rural injectors recruited via respondent driven sampling were obtained using interviewer-administered questionnaires and serologic testing for hepatitis C (HCV). Name-generating questions were utilized to build the sociometric drug injection network to determine network centrality and connectedness to other injectors within the network (k-core and density). A multilevel random effects logistic regression model discerned the independent effects of injection network-related factors on prevalent HCV infection, adjusting for individual-level factors. Results: The prevalence of HCV among rural prescription opioid injectors was 54.6%. Independent of the individual-level variables found to be associated with HCV status (syringe sharing, injecting prescription opioids, injecting cocaine and greater number of years injecting), the more centrally located participants were within the larger injection network, the greater the odds of being HCV-positive (adjust odds ratio: 1.16, 95% confidence interval: 1.03 – 1.32). However, both connectedness measures were not associated with HCV status when individual-level variables were taken into account. Conclusions: This novel research on HCV infection among rural injectors demonstrates the importance of social network factors in characterizing HCV infection among drug users. Specifically, among rural Appalachian opioid injectors, increased interaction with other injectors is associated with a greater likelihood of being HCV positive. Therefore, interventions targeting individual-level risk factors may not be sufficient to prevent HCV transmission among rural prescription opioid injectors.