447. Disease Progression in Patients with Acute Bacterial Skin and Skin Structure Infections: A Comparative Analysis Between Oritavancin and Vancomycin

BACKGROUND: Without the appropriate treatment, acute bacterial skin and skin structure infections (ABSSSI) have the potential to progress to more serious infections such as bacteremia and osteomyelitis. Utilizing single-dose oritavancin rather than vancomycin with step-down oral antibiotics, the need for compliance with outpatient antibiotics is eliminated. The objective of this study was to determine whether oritavancin use may reduce the sequelae from ABSSSI treatment failures, prevent skin infection recurrences, and subsequently improve patient outcomes. METHODS: Patients administered oritavancin or vancomycin for treatment of ABSSSI between May 2017 and March 2019 were included in this retrospective evaluation. The primary endpoint was to determine the 30-day ABSSSI progression rate to bacteremia, osteomyelitis, or endocarditis between treatment arms based on hospital readmissions. Study investigators determined that the source of each resultant infection was from the initial ABSSSI based on the presence of their prior skin infection and cultures, as well as history of present illness and reported patient compliance. In cases of osteomyelitis, infection location was also considered. The secondary endpoint was to determine the ABSSSI readmission rates between treatment arms. Data were analyzed by fisher’s exact test, chi-square test or t-test as appropriate. RESULTS: A total of 99 patients receiving oritavancin and 100 patients receiving vancomycin with prescribed step-down oral antibiotics were identified as meeting inclusion criteria. Eighteen of 100 patients (18%) returned for recurrent ABSSSI infection in the vancomycin arm while 7 of 99 (7.1%) returned in the oritavancin arm (P = 0.0309). Of the 7 returning oritavancin patients, 1 (14.3%) had bacteremia as a result of persistent ABSSSI compared with 7 of 18 (38.9%) patients who previously received vancomycin returned with bacteremia, including 1 case of osteomyelitis (P = 0.0649). CONCLUSION: Utilizing oritavancin for treatment of ABSSSI in this population resulted in improved patient outcomes, significantly fewer hospital readmissions for ABSSSI, and decreased infection sequelae from inadequately treated skin infections. DISCLOSURES: All authors: No reported disclosures.