Emily A. Rosen, Elizabeth M. Krantz, Allison Thibodeau, Keara Kennedy, Leah H Yoke, Frank Tverdek, Zahra Kassamali Escobar, Jason P. Cooper, Masumi Ueda, Paul C. Hendrie, Marco Mielcarek, Catherine Liu
BACKGROUND: The optimal frequency of repeat blood cultures in persistent febrile neutropenia (FN) remains unknown. This study aims to identify opportunities for blood culture diagnostic stewardship in persistent FN. METHODS: This is a retrospective cohort study of patients with hematology/oncology diagnoses and an FN episode >3 days. Generalized estimating equation logistic regression models were used to evaluate risk factors for new bloodstream infection (BSI) after FN day 3. RESULTS: Among 620 patients, median FN duration was 5 days and median blood culture bottles collected per patient was 12. On FN day 1, 25% of patients had a positive blood culture; on FN days 2-9, <5% of patients per day had a new organism isolated. Among 31 new organisms isolated after FN day 3, 8 (26%) were contaminants. Of 503 patients with ≥1 blood culture collected after FN day 3, 19 (4%) had a new BSI after FN day 3. FN onset in the peri-hematopoietic cell transplant (HCT) period (day -7 to +30) was associated with lower odds of new BSI after FN day 3 (OR 0.18; 95%CI [0.04-0.71]; p=0.01).Thirty-six patients died within 30 days after FN day 3, including 4 with a new BSI after FN day 3; 1 death was attributable to BSI after FN day 3. CONCLUSIONS: Detection of new BSI after FN day 3 was uncommon, demonstrating low diagnostic yield of repeat blood cultures after FN day 3. FN episodes in the peri-HCT period may be a potential focus for blood culture diagnostic stewardship initiatives.