Is vaginal reflux associated with urinary tract infection in female children under the age of 36 months?

Purpose To determine the relationship between vaginal reflux (VR) and urinary tract infection (UTI) in female children aged <36 months. Methods A single center retrospective study was performed for 191 girls aged <36 months, with a diagnosis of febrile UTI, who underwent a voiding cystourethrography (VCUG) for assessment of vesicoureteral reflux (VUR) at Sanggye Paik Hospital. Fifty-one girls, who underwent VCUG for assessment of congenital hydronephrosis or renal pelvis dilatation, without a UTI, formed the control group. The correlation between the presence and grade of VR and UTI was evaluated. Results The prevalence rate of VR was higher in the UTI (42.9%) than control (13.7%) group (P<0.05), with a higher VR severity grade in the UTI (mean, 0.64) than control (mean, 0.18) group (P<0.05). On subanalysis with age-matching (UTI group: n=126, age, 5.28±2.13 months; control group: n=22, age, 4.79±2.40 months; P=0.33), both VR prevalence (43.65% vs. 18.18%, P<0.05) and grade (0.65 vs. 0.22, P<0.05) remained higher in the UTI than control group. Presence and higher grade of VR were associated with UTI recurrence (P<0.05). VR was correlated to urosepsis (P<0.05). The renal defect rate of patients with VR (VR [+]/VUR [+]) was not different from that of patients without VR (74% vs. 52%, P=0.143) in the VUR group; however, it was higher than that of VR (+)/VUR (-) patients (74% vs. 32%, P=0.001). If a child with VR (+)/VUR (+) is exposed to a UTI, the risk of renal defect increases. Conclusion Occurrence of VR is associated with UTI recurrence and urosepsis in pediatric female patients.