Recurrent Urinary Tract Infection in Children and VUR

The commonly used definition is: two or more febrile (kidney-involving) infections within a year, or a total of three or more urinary tract infections (febrile or non-febrile). One febrile and one non-febrile infection together also count as recurrent.

Behind recurrent infection there is usually an underlying condition that keeps the bladder from emptying completely or lets urine flow back to the kidney:

• Kidney reflux (VUR): found in roughly 25–40% of children who have had a febrile infection; it makes it easier for bacteria in the bladder to be carried up to the kidney
• Bladder-bowel dysfunction (BBD): a combination of the habit of holding urine, urgency, incomplete emptying, and constipation; the most common cause in a child who has completed toilet training
• Constipation: a full bowel presses on the bladder, prevents complete emptying, and acts as a source of bacteria; most families do not realize their child is constipated
• Structural causes: posterior urethral valves (a congenital membrane in the urethra in male infants), ureterocele and duplex collecting system, ureteral obstruction, stones, neurogenic bladder
• Being uncircumcised in male infants: increases infection risk, especially within the first year of life
• Low fluid intake, holding urine for long periods, poor toilet posture, and hygiene habits

Evaluation begins with a detailed history: the age at which infections occurred, whether they were febrile, culture results, toilet habits, constipation, urinary leakage, a family history of reflux, and, in an infant, antenatal ultrasound findings are all reviewed. In a child who has completed toilet training, a voiding diary and BBD questionnaires are part of this history.

Daily habits reduce the recurrence of infection just as much as treatment aimed at the underlying cause does. Most of these measures are harmless, inexpensive, and effective — in a child with BBD, they are the treatment itself:

• Fluids: drinking water regularly throughout the day; a water bottle at school; cutting back on sugary and carbonated drinks
• Toilet routine: timed voiding on waking, before bed, and every 2–3 hours during the day; not waiting until the urge to go is urgent
• Correct posture: feet flat on the floor or a step stool, knees apart, emptying without rushing or straining; sitting to urinate for boys if needed
• Constipation: aiming for a soft daily bowel movement; fiber and fluids; regular treatment with a stool softener recommended by the physician if needed
• Hygiene: wiping front-to-back in girls; avoiding thick underwear that stays damp and prolonged time in a wet diaper; avoiding local irritation from bubble baths and soap
• Circumcision for male infants: reduces infection risk in infants with reflux or recurrent infection; presented to families as an option
• Early urinalysis with fever: a culture for every unexplained fever; catching the infection early is the single most important step in preventing scarring

Antibiotic prophylaxis (CAP; a single low dose given at night) is used not in every case of recurrent infection but in selected children. Guidelines recommend it to reduce infection recurrence in infants under 1 year with reflux who have had a febrile infection, in high-grade reflux, and while BBD treatment is underway; in a child without reflux, with low-grade reflux, or over age 1 with a single infection, observation is often enough.