Urinary tract infection in children.

Two hundred and eighty-five children under 15 years old (169 boys and 116 girls) who had urinary tract infection (UTI) were admitted to our hospital during the period July 1995 to June 1998. Clinical presentation, laboratory data and image studies were recognized and analyzed. Most patients were younger than 2 years of age. Fever is the most common sign, especially in young children. With the urinary dipstick test a low positive rate of nitrite reaction (34.7%) was found. E. coli is the most common pathogen and exclusively resistant to ampicillin (90.2%). The E. coli is also relatively resistant to trimethoprim/sulfamethoxazole (57.1%). Voiding cystourethrogram was performed in 187 cases, in which 24.6% of those patients showed vesicoureteric reflux. Ninety-eight children received 99mTc-dimercaptosuccinic acid renal scans and 62 cases (63.3%) had abnormal findings compatible with pyelonephritis. The positive predictive values by renal ultrasonography for vesicoureteric reflux and pyelonephritis are 30.7% and 78.9%, respectively. In pyelonephritis patients, only 37% also had a vesicoureteric reflux. The fever duration and clinical inflammatory parameters were evaluated in all patients. Longer febrile periods are the risk of vesicoureteric reflux and pyelonephritis, and a high C-reactive protein concentration indicates the risk of pyelonephritis. In conclusion, fever was the most common sign in young UTI children who had a low positive nitrite reaction rate in the dipstick test. E. coli was the most common pathogen with a high ampicillin resistance in Taiwan. Only 37% pyelonephritis patients had refluxing nephropathy. It is indicated that pyelonephritis is not always attributed to reflux of infected urine. A longer febrile period and a high C-reactive protein level are good indicators for prediction of the risk of pyelonephritis in UTI patients.