Feasibility and clinical outcomes of short-course intravenous antibiotic therapy in neonates under 28 days with urinary tract infection.

UNLABELLED: 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) followed by oral treatment in neonates with UTI. 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. Outpatients and newborns with a postmenstrual age >35+6 weeks were included. 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. 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 course (≤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%, 121/138). ESBL were identified in 3.6% (5/138) 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 feasible and associated with favorable clinical outcomes for carefully selected neonates under 28 days with UTI and low risk factors for severe infection. These findings support a more individualized approach to antibiotic duration in this specific population and warrant prospective multicenter validation.

WHAT IS KNOWN: • Evidence supports short IV antibiotic courses in infants >28 days with UTI. • Robust recommendations are lacking for neonates <28 days.

WHAT IS NEW: • In clinically stable neonates <28 days without bacteremia, short IV therapy was not associated with increased recurrence. • Even neonates <14 days can be safely managed with this approach.