Monday July 01, 2019 from 07:30 to 09:00
Revisiting risk factors for febrile urinary tract infection in infants with prenatal hydronephrosis
Luis H. Braga1, Smruthi Ramesh1, Melissa McGrath1, Anthony Herndon 2.
1Surgery , McMaster University , Hamilton , ON, Canada; 2Urology , VCU , Richmond, VA, United States
Introduction: Risk factors for febrile urinary tract infection (fUTI) in infants with prenatal hydronephrosis (HN), such as female gender, uncircumcised status, high-grade HN, and non-refluxing primary megaureter (NRPM), have been consistently documented in several small sample size series; however, the same cannot be said regarding continuous antibiotic prophylaxis (CAP). Herein, we revisit this clinically important outcome using a large, single-centre database to confirm or refute these previous findings.
Methods: Since 2009, we have prospectively followed 876 consecutive prenatal HN infants <12 months of age with the following conditions: ureteropelvic junction obstruction (UPJO)-like, NRPM and vesicoureteral reflux (VUR). Patients with <6 months followup were excluded. A priori collected variables included: HN Society of Fetal Urology (SFU) grade (low: I/II vs. high: III/IV), HN etiology, CAP, gender, and circumcision status. Primary outcome was catheter specimen fUTI. Time to event curves (hazard ratio [HR]) were analyzed by Cox proportional regression to adjust for confounders. Analyses were done with and without VUR patients.
Results: Of 848 included patients, 632(75%) were male and 36% were circumcised. Seventy-three (9%) had a fUTI at a median age of six months (interquartile range [IQR] 9). Mean followup was 30 months (6–120). High-grade HN was seen in 467 (55%) infants and CAP prescribed for 450 (53%). VUR (68% grades IV–V) was detected in 168/572 (29%) patients who had a voiding cystourethrogram (VCUG). Upon univariate analysis, a significantly higher fUTI rate was seen in females, uncircumcised males, patients with NRPM, and those with high-grade HN (Table 1). In the Cox proportional regression model, NRPM (HR 4.8; p<0.01), VUR (HR 7.0; p<0.01), uncircumcised male (HR 2.3; p=0.03), females(HR 2.5; p=0.02), and lack of CAP (HR 3.7; p<0.01), were significantly associated with fUTI (Table 2). HN grade was not found to be associated with fUTI. Kaplan-Meier curves for fUTI risk factors are shown in Fig. 1.
Conclusions: This study validates previous findings, confirming NRPM, VUR, uncircumcised status, and female gender as important risk factors for fUTI. According to our large dataset analysis, CAP significantly reduced fUTIs and should be offered to these high-risk HN patients.