1860. Streptococcus mitis/oralis sepsis in patients with neutropenia after chemotherapy

Abstract

Abstract Background Streptococci are the dominant species in the human oral cavity and upper respiratory tract. Oral mucositis affects 30–40% of the patients receiving chemotherapy and 80% undergoing HSCT. During episode of oral mucositis, patients are at a risk for invasive infections caused by opportunistic pathogens in the oral cavity. The purpose of this study was to investigate the clinical characteristics of S. mitis/oralis invasive infection, and find patients at high risk for with S. mitis/oralis infection in order to prevention of S. mitis/oralis bacteremia. Methods Patients receiving chemotherapy or stem cell transplant for malignancies and primary immunodeficiencies at the pediatric bone marrow transplant center of Seoul St. Mary's hospital admitted during January 2017 to December 2020 for blood stream infections were included in this study. Chart review of the patients were done retrospectively. Results During the four year study period, there were 4,647 admissions, and 2,358 (50.7%) experienced at least 1 episode of fever. Overall, the incidence of bacteremia was 10.9% of all febrile children. The most common pathogen causing bacteremia was S. mitis/oralis (24%), followed by E. coli (14.3%), Klebsiella spp. (10.5%), and S. epidermidis (7.4%). Candida sepsis occurred in 3.5% of the children. By year, the proportion of bacteremia caused by S. mitis/oralis was 19% in 2017, 21% in 2018, 41% in 2019, and 25% in 2020. 51% of S. mitis/oralis bacteremia occurred 8-14 days after day 0 of chemotherapy. A multivariate analyses on risk factors for S. mitis/oralis bacteremia was the underlying disease AML (OR, 4.6; 95% CI, 2.4-8.7; P< 0.001), and the use of cytarabine (OR, 4.5; 95% CI, 2.4-8.5; P< 0.001). Compared to ALL, AML has a HR 3.7 (95% CI 1.9-7.2) of bacteremia with S. mitis/oralis. Prolonged duration of fever ( >7 days) was observed in 13.4% of the patients, and a fever duration >14 days was observed in 2 patients. Complications such as septic shock, n=4 (6.0%), ARDS, n=1 (1.5%), infective endocarditis, n=2 (3.0%) were observed. Conclusion S. mitis/oralis sepsis causes significant morbidity in patients undergoing treatment for malignancies. Patients with AML are at the highest risk, especially after induction or consolidation chemotherapy including cytarabine. Disclosures All Authors: No reported disclosures.