Abstract

"Purpose: Febrile urinary tract infection (UTI) is common in infants and is associated with the risk for renal scarring and long-term complications. We retrospectively investigated the risk factors for recurrent UTI in infants with febrile UTI. Materials and Methods: We identified 108 infants (mean age 4.5±3.2 months; range 1-12 months) with febrile UTI who visited the emergency room from January, 2007 to December, 2010. We retrospectively reviewed sex, age, urine analysis, pathogen, leukocytosis, C-reactive protein (CRP), hydronephrosis, hydronephrosis grade and severity, vesicoureteral reflux (VUR), VUR grade and severity. We performed comparative studies of infants with recurrent UTI (group A; n=20, 18.5%) and primary UTI (group B; n=88, 81.5%). High-grade hydronephrosis and high-grade VUR were both defined as grade 3 or higher. Results: In 108 infants with febrile UTI, the male to female ratio was 3.2:1 (82 boys, 26 girls). On cross analysis of group A and B, there was no significant difference according to sex, age, CRP level in serum, leukocytosis and inflammation markers in urine analysis (p>0.05). Comorbidity of hydronephrosis and VUR was 52.8% (n=57) and 13.9% (n=15), respectively. Group A had more high grade hydroneprhosis, high grade reflux, bilateral reflux and a non-Escherichia coli strain in the urine culture compared with group B (p<0.05).The presence and laterality of hydronephrosis was not significantly different (p>0.05). Conclusions: During the first year after birth, high grade VUR, bilateral VUR, and a non-E. coli strain in the urine culture significantly increases the risk of recurrent UTI. Therefore, in infants with febrile UTI, imaging studies and urine culture are important for evaluation of recurrence probability."

• Keywords: Urinary tract infection, Infants, Risk factors