463. Evaluation of Trimethoprim-Sulfamethoxazole Utilization for Skin and Soft-Tissue Infections During Emergency Department Visits at Two Community Teaching Hospitals

BACKGROUND: Increasing trimethoprim/sulfamethoxazole (TMP/SMX) resistance has been noted among inpatient and outpatient isolates of methicillin-resistant S. aureus (MRSA) at two community teaching hospitals in Northern New Jersey. The purpose of the study is to evaluate the indications for TMP/SMX prescriptions for adult Emergency Department (ED) discharges. In addition, since IDSA guidelines for the management of skin and soft-tissue infections (SSTIs) do not recommend the use of anti-MRSA antibiotics for non-purulent SSTIs, we chose to determine guideline concordance of antibiotic selection for non-purulent SSTIs. METHODS: TMP/SMX susceptibility data for S. aureus from 2014 to 2018 at two community teaching hospitals were compiled. A retrospective chart review was then conducted of all adult patients who were discharged from the ED with an antibiotic prescription from January to March 2019. Antibiotic indications were extracted based on ED diagnosis and review of the medical record. In patients treated for non-purulent cellulitis, antibiotic prescription information and antibiotic allergies were collected and assessed for guideline concordance. Guideline-concordance for non-purulent cellulitis was defined as treatment with B-lactams or clindamycin. RESULTS: TMP/SMX susceptibility against S. aureus is displayed in Figure 1. Of 338 patients discharged with a prescription for TMP/SMX, 60% were treated for SSTIs, 30% were treated for urinary tract infections, and 10% were treated for other indications. Among 203 patients treated with a TMP/SMX-containing regimen for SSTIs, 76% had purulent or wound-related infection. Of 137 patients treated for non-purulent cellulitis, 68% of antibiotic regimens were guideline-concordant. In addition, 19% of antibiotic regimens for non-purulent cellulitis contained TMP/SMX. CONCLUSION: A substantial reduction in TMP/SMX susceptibility among MRSA, but not MSSA, isolates has been observed. Opportunities to improve utilization of TMP/SMX for SSTIs exist at our institutions. Additional studies are warranted to determine the factors associated with increasing TMP/SMX resistance in MRSA. [Image: see text] DISCLOSURES: All authors: No reported disclosures.