Impact of ciprofloxacin prophylaxis on blood stream infection during early treatment phase of pediatric acute lymphoblastic leukemia: An observational cohort study

Purpose: Data on the efficacy of antibiotic prophylaxis in children with acute lymphoblastic leukemia (ALL) is scarce and recent guidelines advise against its use. This study is conducted to evaluate if the use of ciprofloxacin prophylaxis is associated with a decrease in blood stream infection (BSI) incidence in children with newly diagnosed ALL. Methods: This was a retrospective, observational cohort study. Patients were newly diagnosed with ALL between 2020 and 2021 (prophylaxis group) or 2021–2022 (no prophylaxis group). Primary outcome was occurrence of BSI caused by Gram-negative pathogens or Staphylococcus aureus during induction or consolidation I. Secondary outcomes were Pediatric Intensive Care Unit (PICU) admission, mortality, ciprofloxacin resistance and Clostridioides difficile-associated diarrhea (CDAD). Results: Two hundred patients were included (prophylaxis group n=94, no prophylaxis group n=106). Ciprofloxacin prophylaxis was associated with significantly lower BSI-incidence (HR 0.37; 95 % CI 0.15–0.94) There was no significant difference for BSI-related PICU admission (OR 0.37; 95 % CI 0.04–3.61), BSI-related mortality (1.1 % vs 0 %), all-cause mortality (OR 0.55; 95 % CI 0.10–3.10), and short-term resistance rates (16.0 % vs 13.0, OR 1.2; 95 % CI, 0.57–2.74) or CDAD (0 % vs 0.9 %) between the prophylaxis group and no prophylaxis group. Conclusion: The use of ciprofloxacin prophylaxis was associated with a significantly lower incidence of BSI. While this finding shows the beneficial effect of ciprofloxacin prophylaxis in the first treatment phase of ALL, RCTs with a large sample size are needed, particularly to assess the effect on ciprofloxacin resistance.