Prevalence and correlates of abscesses among a cohort of injection drug users

Recent studies have indicated that injection-related infections such as abscesses and cellulitis account for the majority of emergency room visits and acute hospitalizations accrued by local injection drug users. The objective of this analysis was to examine the prevalence and correlates of developing an abscess among a cohort of injection drug users in Vancouver and to identify socio-demographic and drug use variables associated with abscesses at baseline. We examined abscesses among participants enrolled in a prospective cohort of injection drug users. Categorical variables were analyzed using the Pearson's chi-square test and continuous variables were analyzed using the Wilcoxon signed rank test. Among 1 585 baseline participants, 341 (21.5%) reported having an abscess in the last six months. In a logistic regression model that adjusted for all variables that were associated with having an abscess at p < 0.1 in univariate analyses, female gender [odds ratio (OR) = 1.7, [95% CI: 1.2 - 2.4]; p = 0.002), recent incarceration (OR = 1.7, [95% CI: 1.3 - 2.2]; p < 0.001), sex trade involvement (OR = 1.4 [95% CI: 1.0 - 2.0]; p = 0.03), frequent cocaine use (OR = 1.5 [95% CI: 1.2 - 2.0]; p = 0.002) and HIV serostatus (OR = 1.5, [95% CI: 1.2 - 2.0]; p = 0.003) were positively associated with having an abscess. Explanations for these associations require further study, and interventions are needed to address this highly prevalent concern.