Simple ultrasound examination may avoid complex tests for children with urinary tract infection

For infants and young children with urinary tract infection (UTI) seen in the ER, a simple ultrasound examination may avoid the need for more complex x-ray tests, reports a study in the May issue of The Pediatric Infectious Disease Journal. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

The study also finds that many children diagnosed with their first UTI are infected with antibiotic-resistant bacteria. The lead author was Dr. Khalid Ismaili of Hôpital Universitaire des Enfants-Reine Fabiola, Brussels.

New Insights on 'Characteristics and Clinical Evolution' of UTI in Small Children
The researchers analyzed data on 209 children seen at their hospital's emergency department with fever and UTI. Sixty-three percent of the patients were girls; three-fourths were less than two years old when UTI was diagnosed.

In more than 90 percent of children, the infection was caused by the intestinal bacteria Escherichia coli (E. coli). Many of these children were infected with antibiotic-resistant strains of E. coli bacteria. This included a 58 percent rate of bacteria resistant to ampicillin—a penicillin antibiotic widely used as initial treatment for UTI.

The study also found that ultrasound can play an important role in detecting (VUR), or "backwards" flow of urine from the bladder upwards toward the kidney. It's important to detect and treat VUR—a common cause of UTI that can put children at risk of long-term kidney damage. In the study, all patients first underwent a simple ultrasound examination, followed by an x-ray test called voiding cystourethrography (VCUG) in which dye is injected into the bladder.

The results showed VUR (generally mild) in 25 percent of the children. All but a few of these cases were also detected on ultrasound. Thus the much-simpler ultrasound test provided useful information on the likelihood of VUR and related abnormalities—including possible birth defects of the urinary tract. "The presence or absence of abnormal ultrasound represents the key for deciding about VCUG studies," Dr. Ismaili and co-authors write.

Eleven percent of the children in the study had recurrent infections at up to 2½ years' follow-up. All of the children with recurrent infections had normal ultrasound and VCUG results.

Urinary tract infection is one of the most common types of infection in children—eight percent of girls and two percent of boys have at least one UTI before age 7. The new study provides health care providers with important new information on the "characteristics and clinical evolution" of infants and young children with their first UTI.

The results show that most children experiencing their first UTI are girls under two years old. Many of these infections are caused by antibiotic-resistant bacteria, which may require adjustments to treatment.

The findings also suggest that about one-fourth of young children with UTIs have VUR, which can be reliably detected by a simple ultrasound examination. Dr. Ismaili and colleagues conclude, "Ultrasound is an excellent screening tool that allows avoidance of unjustified VCUG studies."