Febrile urinary tract infections in 0- to 3-month-old infants: a prospective follow-up study

Area of Science:

• Pediatrics
• Infectious Diseases
• Nephrology

Background:

• Febrile urinary tract infections (UTIs) in infants under 3 months require careful management due to potential renal sequelae.
• Understanding uropathogen prevalence and antimicrobial resistance is crucial for effective treatment.

Purpose of the Study:

• To investigate the clinical course of febrile UTIs in infants aged 0-3 months.
• To determine uropathogen frequencies, antimicrobial resistance patterns, and the incidence of renal abnormalities.
• To analyze sex-based differences in febrile UTI presentation and outcomes.

Main Methods:

• Prospective observational study of 46 infants (0-3 months) with their first UTI.
• Renal ultrasound and voiding cystourethrography performed on all participants.
• Analysis of uropathogen identification and antimicrobial susceptibility testing.

Main Results:

• Infants under 3 months constituted 21% of first UTIs, with males (74%) more affected than females (26%).
• Escherichia coli was the predominant pathogen (88%), exhibiting high resistance to ampicillin (71%) and trimethoprim/sulfamethoxazole (47%).
• Vesicoureteral reflux (VUR) was found in 21% of cases, mostly low-grade and resolving spontaneously by age 2. Normal ultrasounds still showed a 10% incidence of low-grade VUR.

Conclusions:

• Infants under 3 months represent a significant proportion of febrile UTI cases, predominantly caused by antibiotic-resistant E. coli.
• Male infants are disproportionately affected by febrile UTIs.
• The risk of missing significant renal abnormalities is low in infants with normal renal ultrasound findings.