The epidemiology of cutaneous injection-related infection among injection drug users at a supervised injection facility

Background: To date, there is limited understanding of the epidemiology of cutaneous injection-related infections (CIRI), including abscesses and cellulitis, among persons who inject drugs (IDU). The objectives of this thesis were to: describe the microbiology of wounds among IDU; examine the correlates of developing a CIRI; investigate determinants of CIRI care at a supervised injection facility (SIF); model predictors of Emergency Department (ED) visits for CIRI; and explore predictors of hospitalization for CIRI or related infectious complications. Methods: Quantitative data was derived from a prospective cohort study established to evaluate a SIF in Vancouver, Canada. A random sample of 1083 IDU attending the SIF were asked to complete an interview-administered questionnaire, undergo semi-annual HIV and hepatitis C virus testing and to consent to hospital database linkage. Results: Nearly 25% participants with a wound had a culture positive for community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA). Female sex, living in unstable housing, borrowing a used syringe, requiring assistance with injection and cocaine injection at least daily were associated with developing a CIRI. Female sex, living in unstable housing and heroin injection daily or more frequently were associated with receiving CIRI care by nurses at the SIF. Being referred to hospital by a nurse at the SIF was predictive of ED use for CIRI. Among females, residing in Vancouver’s Downtown Eastside was associated with an increased likelihood of ED use for CIRI, whereas among men, requiring assistance with injecting and being HIV positive were associated this outcome. Participants were more likely to be hospitalized for a CIRI or related infectious complication if they were HIV positive and referred to hospital by a nurse at the SIF. Importantly, length of stay in hospital was significantly shorter and less expensive among participants referred to hospital by a nurse at the SIF. Conclusions: CIRI are common among IDU in our setting and are associated with a number of individual harm and environmental factors. Our findings support the need for prevention and treatment efforts to reduce the burden of CIRI. Additional improvements in treatment protocols, such as wound management clinics within harm reduction services, are urgently needed.Medicine, Faculty ofPopulation and Public Health (SPPH), School ofGraduat