Epidemiological and clinical characteristics of the first documented urinary infection in children

Epidemiological and clinical characteristics were investigated in 265 hospitalised patients (103 M,162 F) aged 0.1 to 11 years (mean 1.43 years) with their first documented urinary infection (UI). Of the studied population 182 patients were less than three (69%) and 83 patients (31%) more than three years old. Most infants were less than four months (57%) with a domination of boys and after the sixth month there were mostly girls. Evaluation of clinical symptoms revealed fever in most patients (63%) being most prevalent in older infants (75%). E. coli was isolated in 78% of patients. According to fever (> 38 °C) and the presence of more than two criteria (ESR > 20mm/h, L >10 103/mm3, CRP >20mg/L, urine osmolarity < 500mOsm/L, izoLDH fV > 30% and leucocytes casts in urine) a total of 194 patients (73%) had acute pyelonephritis. The significance of clinical and laboratory tests by regression analysis was undertaken. The significant clinical predictors of a variance of diagnosis proved to be fever, lethargy, distended abdomen and loin pain (R2 = 0.52) with increased ESR, leucocytosis and positive CRP test (R2 = 0.56). Combining symptoms and tests the significant predictors differed according to age: up to one (R2 = 0.61), one to three (R2 = 0.55) and more than three years (R2 = 0.76) with incomplete variance in 39%, 45% and 24% of the diagnosis respectively. Common predictors proved to be fever and ESR in all, with loin pain and positive CRP test in patients with more than one year of age. The results presented disclosed a prevalence of acute pyelonephritis in most infants. Clinical symptoms and laboratory tests proved valuable especially in the differentiation of acute pyelonephritis. Incomplete variance of the diagnosis necessities implementation of diagnostic imaging in all children with UI, particularly patients with acute pyelonephritis in the first three years.