Ureteral dilatation in children with febrile urinary tract infection or bacteriuria

Little information is available on the relationship between urinary infection in children and infants, with or without vesicoureteral reflux, and dilatation of the urinary tract. The purpose of this study was to determine the effects of infection and reflux on the diameter of the ureter at excretory urography in children with acute, febrile urinary tract infections and in infants with bacteriuria found at screening. Standardized measurements of ureteral diameter were obtained for 79 children (2 months to 6 years old) with urinary tract infections and for 45 infants with bacteriuria. Patients with urinary tract obstruction or malformations were excluded. Seventy-one children with febrile urinary tract infection had ureteral visualization that allowed measurements. Ureteral diameter in this group was significantly wider than in a reference group, and 42 children (59%) had ureteral diameters that were more than 2 standard deviations above the normal mean. Ureteral diameter at excretory urography increased with increasing grades of reflux, but dilatation occurred also in the absence of reflux. Twenty-two of the 45 infants in the group with bacteriuria had sufficient ureteral visualization for measurements. The ureters in this group were wider than in the reference group, and eight infants had ureteral diameters that were more than 2 standard deviations above the normal mean. We conclude that ureteral dilatation is a common effect of acute urinary tract infection and bacteriuria in children.