Safe and effective short-course intravenous antibiotic therapy in neonates under 28 days with urinary tract infection

Aims Evidence guiding the optimal duration of intravenous (IV) antibiotic therapy for urinary tract infections (UTI) in neonates under 28 days remains scarce. This study aimed to evaluate the feasibility and safety of a short IV antibiotic course (≤ 4 days) in neonates with UTI. Methods We conducted a retrospective single-center study including neonates < 28 days hospitalized for culture-proven UTI (≥ 10,000 leukocytes/mL and ≥ 10,000 CFU/mL of a single pathogen). Demographic, clinical, laboratory, imaging, and treatment data were collected. Patients were stratified as low-risk (no severity criteria) or high-risk (clinical severity, bacteremia, pyelo-ureteral dilatation, or ESBL infection). The primary endpoint was 30-day recurrence after IV therapy. Results A total of 138 patients were included; (82% male, median age 15.5 days). 97 patients (71%) were classified as low-risk, and 95 of them (98%) received a short IV antibiotics (≤ 4 days). Only one early recurrence occurred related to poor oral intake of antibiotic treatment during viral co-infection. Escherichia coli was the predominant pathogen (88%). ESBL identified in 3.6% of neonates. Fifty-one patients (37%) were younger than 14 days, they presented less frequently with fever but received similar short IV courses without increased recurrence. Conclusion Short-course IV antibiotic therapy followed by oral treatment appears safe and effective for carefully selected neonates under 28 days with UTI and low risk factors for severe infection. These findings support a more tailored approach to antibiotic duration in this age group and call for prospective multicenter validation.