338. Epidemiology and Treatment of Invasive <i>Bartonella spp.</i> Infections

Abstract Background Serology and PCR testing methods have increased ability to diagnose Bartonella spp. invasive infections. Current treatment recommendations are based primarily on case series aging data published before newly available diagnostic techniques. These limited in safety effectiveness outcomes. This multicenter, retrospective cohort study describes the epidemiology outcomes of bartonellosis among patients U.S. Methods Collaborating sites were selected from SERGE-45 (Southeastern Research Group Endeavor) research network. Data collected through REDCap. Subjects screened adult with diagnosis codes, positive serologies, PCR, 16/18S tests, cultures, Karius® tests blood or tissue between January 1, 2014, September 2021. Eligible had at least one test result, evidence bartonellosis, received for bartonellosis. Treatment failure was defined as admission readmission while treatment, mortality during within 30 days after end required escalation extended duration therapy, premature discontinuation necessitated change regimen. Those not meeting criteria considered success. Results Of 169 screened, 32 included, 19 having henselae most common causative pathogen (n = 31, 97%). Endocarditis manifestation 18, 56%). regimens displayed Table 1. Primary reasons included therapy course 4, 30.8%) due adverse effect 30.8%). Conclusion Doxycycline rifampin regimen durations used compared often referenced 6-week courses It is important consider drug effects, toxicities, tolerability being treated Disclosures P. Brandon Bookstaver, PharmD, Spero Therapeutics: Advisor/Consultant.