Comparative 1-Year Outcomes of Invasive Staphylococcus aureus Infections Among Persons With and Without Drug Use: An Observational Cohort Study

Abstract

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.

Description and outcomes of patients with substance use disorder with serious bacterial infections who had a multidisciplinary care conference

“…However, in a previous study, 70% of patients with SUDs were found to complete Staphylococcus aureus bacteremia treatment, which is similar to the treatment completion in our cohort without a conference. 32 Of patients who had an OPTIONS-DC, 83.6% completed treatment. We hypothesize that OPTIONS-DC may increase the likelihood of long-term antibiotic treatment completion in patients with SUDs and would be important to evaluate in future studies.…”

Whole genome sequencing reveals two genetically distinct MRSA outbreaks among people who inject drugs and homeless people in Copenhagen

“…A Danish study by Thønnings et al [24] found that hospitalized PWID had an overall bacteremia rate of 22% with S. aureus being the most common pathogen. In a retrospective cohort study Appa et al [25] comparing S. aureus invasive infections in PWID with non-PWID, they found a significantly higher rate of endocarditis, deep-seated infections, vertebral osteomyelitis and MRSA in the PWID group. Furthermore, they found that a significant lower number of PWID completed their antibiotic treatment and a higher readmittance rate with S. aureus infection 1 year following discharge.…”

The IMPACT (Infection Management Plus Addiction Care Together) Pilot: A Case Series of Combined Contingency Management for Substance Use Disorders and Antibiotic Adherence in the Hospital Setting

“…While there is no formal comparison group in this small pilot study, we note that in a previously published cohort study of a similar population not receiving CM, antibiotic completion for PWUD with serious bacterial infections was 69% and 25% self-directed their discharge. 1 Moreover, IMPACT participants described that this intervention was effective in encouraging antibiotic completion, citing satisfaction with the visits breaking up the long acute care stay, developing a trusting relationship, and the financial incentives.…”

“…S uccessful treatment of serious infections among people who use drugs (PWUD) remains challenging given undertreated substance use disorders (SUD), stigma, competing life priorities, and more limited discharge options after hospitalization compared with non-PWUD. [1][2][3] Contingency management (CM), a behavioral treatment anchored in operant conditioning that involves frequent assessment of objective behavior change with paired incentives, is an underused strategy that has proven efficacious in addressing SUD and separately infection treatment adherence. Numerous randomized trials have supported CM efficacy in treating methamphetamine use disorder, cocaine use disorder, and opioid use disorder, with additional studies demonstrating CM efficacy in HIV, hepatitis C, and tuberculosis treatment.…”