A 3-year-old has just completed a 7-day course of amoxicillin for a second febrile urinary tract infection and now has a negative urine culture. What is the next course of action?

• A. Renal and bladder ultrasound.
• B. Prescribe prophylactic antibiotics to prevent recurrence.
• C. Refer the child for a voiding cystourethrogram.
• D. Screen urine regularly for leukocyte esterase and nitrites.

Answer: (A)

In kids with febrile urinary tract infections, repeated episodes raise suspicion for an underlying urinary tract abnormality that predisposes to infection, so imaging to look for anatomical issues is the next important step after completing treatment and obtaining a current negative culture. A renal and bladder ultrasound is the best first move because it is noninvasive, quick, and can reveal structural problems such as hydronephrosis, ureteral dilation, bladder abnormalities, or signs suggestive of vesicoureteral reflux. Detecting such abnormalities helps determine whether further testing, like a voiding cystourethrogram, is needed. Prophylactic antibiotics aren’t routinely started based solely on a second febrile UTI without imaging findings, and routine screening of urine with leukocyte esterase and nitrites isn’t indicated in this scenario.