Relationship between urinalysis findings and responsible pathogens in children with urinary tract infections.

ABSTRACT

BACKGROUND: Pyuria, presence of bacteria, leukocyte esterase, and nitrite positivity in urinalysis should be considered together, and simultaneous urine culture test should be performed in the diagnostic evaluation of urinary tract infection (UTI). The absence of pyuria in urinalysis cannot exclude UTI in patients with suggestive clinical findings. OBJECTIVE: It was aimed to assess relationship between urinalysis tests and uropathogen and to evaluate antibiotic resistance in children. METHODS: The study included patients (aged 0-18 years) with significant uropathogen growth in urine culture tests. The patients' data regarding age, gender, results of urine microscopy, urine culture, and antibiogram were recorded retrospectively. RESULTS: Overall, 705 patients (562 girls, 143 boys) with significant growth in urine culture test were included. Median age was 72 months among girls and 12 months among boys. Most common uropathogens were Escherichia coli (79.6%) and Klebsiella pneumoniae (8.2%). E. coli was more commonly among girls (87%) and Klebsiella spp. among boys (53.3%). Pyuria was positive in urinalysis in 75% of patients. Pyuria presence was more common in patients with E.coli or Proteus spp. (80.6% and 71.4%, respectively) than those with Enterococcus spp. and Klebsiella spp. (52.0% and 53.3%, respectively). In culture antibiogram tests, ampicillin resistance was 100% in Klebsiella oxytoca and Enterobacter spp. and 72% in E. coli strains. No ceftriaxone resistance was observed in K. oxytoca, Citrobacter spp., Pseudomonas aeruginosa, and Enterobacter spp. DISCUSSION: Most UTIs were seen in older girls. Pyuria might be lacking in UTIs associated to Klebsiella spp. and Enterococcus spp., and absence of pyuria may not exclude UTI in patients with compatible clinical findings. Ceftriaxone is still an option in empirical treatment; unnecessary use of third-generation cephalosporins should be avoided, particularly in infections other than UTI. CONLUSIONS It was found that E. coli more commonly caused leukocyturia, leukocyte esterase positivity, and pyuria; that pyuria might be lacking in UTIs associated to Klebsiella spp. and Enterococcus spp. and that pyuria was more prevalent among girls. It is though that urine culture tests should be performed in children with suspected UTI even in the absence of pyuria because lack of pyuria may lead delay in diagnosis and treatment as well as renal scar formation.