The Clinical and Financial Burden of Spinal Infections in People who Inject Drugs.

Abstract

BACKGROUND: People who inject drugs (PWID) are known to be at increased risk of infectious diseases including bacterial and blood-borne viral infections. However, there is limited literature surrounding the burden of spinal infections as a complication of injecting drug use (IDU). AIMS: To quantify the clinical and financial burden of IDU-related spinal infections. METHOD(S): Retrospective chart review of adult PWID with spinal infections requiring hospital admission to a tertiary health service in Melbourne, Australia between 2011 and 2019. RESULT(S): Fifty-seven PWID with 63 episodes of spinal infections were identified with a median hospital stay of 47days (IQR 16, range 4-243). One-third of episodes required neurosurgical intervention and 11 episodes (17%) required intensive care unit (ICU) admission (range 2-17days). Staphylococcus aureus was the most common causative pathogen, present in three-quarters of all episodes (n = 47). The median duration of antibiotic regime was 59days (IQR 42) and longer courses were associated with known bacteraemia (p = 0.048), polymicrobial infections (p = 0.001) and active IDU (p = 0.066). Predictors of surgery include neurological symptoms at presentation (RR 2.6; p = 0.010), inactive IDU status (RR 3.0; p = 0.002), a diagnosis of epidural abscess (RR 4.1; p = 0.001) and spinal abscess (RR ; p <0.001). Completion of planned antimicrobial therapy was reported in 51 episodes (82%). Average expenditure per episode was AUD $61577. CONCLUSION(S): Spinal infections in PWID are an underreported serious medical complication of IDU. Though mortality is low, there is significant morbidity with prolonged admissions, large antimicrobial requirements and surgical interventions generating a substantial cost to the health system. This article is protected by copyright. All rights reserved.