The Clinical Comparison between Monomicrobial and Polymicrobial Urinary Infection in Febrile Pediatric Acute Pyelonephritis

ABSTRACT

PURPOSE: We investigated the clinical presentation of febrile pediatric patients with acute pyelonephritis (APN) with a mixed urine culture from an aseptic urine sample, and compared with that of those with a single culture. METHODS: We retrospectively reviewed the medical charts of 95 patients diagnosed as APN with fever between January 2008 and October 2010 at Korea University Medical Center. We classified the patients with APN into two groups with a positive single culture (S group) and a positive mixed culture (M group) from an aseptic urine sample of suprapubic bladder aspiration or urethral catheterization and compared the fever duration, laboratory markers such as serum white blood cell (WBC) counts and C-reactive protein (CRP) values in peripheral blood, and the presence of hydronephrosis, renal scar and vesicoureteral reflux (VUR) between the two groups (If presence of hydronephrosis, scar and VUR=1 and no=0). RESULTS: Total pediatric patients with febrile APN were 95 patients, a positive S group was 89 patients and a positive M group was 6 patients. Fever duration (S vs. M, 4.7+/-3.1 vs. 6+/-5.7 days), serum WBC (S vs. M, 18,630+/-6,483 vs. 20,153+/-7,660/microL) and CRP (S vs. M, 100.6+/-2.46 vs. 81.1+/-0.09 mg/L) values, and the presence of hydronephrosis, renal scar and VUR were not different between the two groups. CONCLUSION: Our data shows that there were no specific differences of clinical manifestation between a positive single urine culture and a positive mixed urine culture in pediatric APN. A mixed urine culture from an aseptic urine sample should be interpreted cautiously.