Comparative one-year outcomes of invasive Staphylococcus aureus infections among persons with and without drug use: an observational cohort study

Clin Infect Dis. 2021 Apr 27:ciab367. doi: 10.1093/cid/ciab367. Online ahead of print.


BACKGROUND: Persons who use drugs (PWUD) face substantial risk of Staphylococcus aureus infections. Limited data exist describing clinical and substance use characteristics of PWUD with invasive S. aureus infections or comparing treatment and mortality outcomes in PWUD vs. non-PWUD. These are needed to inform optimal care for this marginalized population.

METHODS: We identified adults hospitalized from 2013-2018 at 2 medical centers in San Francisco with S. aureus bacteremia or ICD-coded diagnoses of endocarditis, epidural abscess, or vertebral osteomyelitis with compatible culture. In addition to demographic and clinical characteristic comparison, we constructed multivariate Cox proportional hazards models for one-year infection-related readmission and mortality, adjusted for age, race/ethnicity, housing, comorbidities, and MRSA.

RESULTS: Of 963 hospitalizations for S. aureus infections in 946 patients, 372/963 (39%) occurred in PWUD. Among PWUD, heroin (198/372, 53%) and methamphetamine use (185/372, 50%) were common. Among 214 individuals using opioids, 98/214 (46%) did not receive methadone or buprenorphine. PWUD had lower antibiotic completion than non-PWUD (70% vs. 87%; p<0.001). While drug use was not associated with increased mortality, one-year readmission for ongoing or recurrent infection was double in PWUD vs. non-PWUD (28% vs. 14%; aHR 2.0 [95% CI:1.3-2.9). MRSA was independently associated with one-year readmission for infection (aHR 1.5 [95% CI 1.1-2.2]).

CONCLUSION: Compared to non-PWUD, PWUD with invasive S. aureus infections had lower rates of antibiotic completion and twice the risk of infection persistence/recurrence at one year. Among PWUD, both opioid and stimulant use were common. Models for combined treatment of substance use disorders and infections, particularly MRSA, are needed.

PMID:33904900 | DOI:10.1093/cid/ciab367