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