Six hundred infants, 315 girls and 285 boys less than 2 years of age, were examined to determine the existence of significant bacteriuria. A prevalence of 4.7% (7% girls and 2% boys) was found in a middle-class white population. Sixteen infants, or 2.7%, were asymptomatic when significant bacteriuria was diagnosed. Three infants had an intractable diaper rash but no other signs of infection. Nine infants had symptomatic urinary tract infections.
Radiographic evaluation showed that 13% of those studied had an abnormal excretory urogram (IVP) and 48% had vesicoureteral reflux of which 24% was severe grade 3. One infant required surgery (pyeloureteroplasty); three other infants with primary reflux may require ureteroneocystostomies in the future. Seven of the 28 infants, or 25%, were below the tenth percentile in weight at the time of diagnosis.