• Clinical and Experimental Pediatrics
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• v.52 no.10
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• pp.1147-1152
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• 2009

Purpose:To characterize the pathogens and their antibiotic susceptibilities in more than 24-month-old children with urinary tract infection (UTI) and to study the Escherichia coli antimicrobial susceptibility trend. Methods:We retrospectively reviewed the record of more than 24-month-old children with UTI between January 2003 and December 2008. Positive results for 1 bacterial species with a colony count of ${\geq}10^5CFU/mL$ was considered statistically significant. We analyzed uropathogens and their antibiotic susceptibilities. To investigate E. coli antibiotic susceptibility trend, we compared 2 study periods (group A: 2003-2005 versus group B: 2006-2008) using the chi-square test for trend. Results:In all, 63 bacterial isolates were identified in children with febrile UTI. The most common pathogen was E. coli (77.8%). There was no difference in the resistance patterns of uropathogens during the 2 study periods (P>0.05). Antibiotic susceptibility of the E. coli isolates to aztreonam, cefotetan, cefotaxime, ceftriaxone, cefepime, amikacin, and imipenem was >90% to trimethoprim/sulfamethoxazol, 49% and to ampicillin and ampicillin/sulbactam, 20-25%. Over the 2 study period, the E. coli susceptibilities to most antibiotics did not change: the susceptibility to cefuroxime increased from 74.1% to 95.5% (P=0.046) and that to ciprofloxacin increased from 59.3% to 86.4% (P=0.039). Conclusion:Empirical treatment with trimethoprim/sulfamethoxazole, ampicillin, and ampicillin/sulbactam alone appeared to be insufficient in childhood UTI because of the high resistance of E. coli and other gram-negative uropathogens. Antibiotics for empirical therapy should be selected based on the sensitivity and resistance pattern of uropathogens found in a particular region.

• Childhood Kidney Diseases
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• v.12 no.1
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• pp.54-61
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• 2008

Purpose: This study was performed to assess necessity of voiding cystourethrography (VCUG) for infants with urinary tract infection (UTI) who had both normal renal sonography and normal DMSA renal scans. Methods: We reviewed 117 infants hospitalized for UTI between February 2002 and July 2007 at Sanggye Paik Hospital. The diagnosis of UTI was made by culture from a urine specimen obtained by suprapubic puncture(n=57), catheterization(n=58), or collection bag method (n=2, twice positive culture of the same organism). All patients had undergone renal sonography, DMSA renal scan and VCUG. Children with both normal renal sonography and normal DMSA renal scans were evaluated for the presence or severity of vesicoureteral reflux (VUR). Results: Of the 117 patients, 96 were boys and 21 were girls. 28 patients(23.9%) had VUR. 59(50.4%) showed both normal renal sonography and normal DMSA renal scans. Among these 59 patients, 7(11.9%) showed VUR. Three of them had grade I-II reflux, two grade III reflux, and the other two grade IV reflux. One of them showed bilateral VUR, grade IV reflux on the right and grade III on the left. Conclusion: Although the negative predictive value of both normal renal sonography and normal DMSA renal scan for VUR was 88.1%, 7 patients had VUR and two of them had high grade reflux(grade IV). So, we suggest that VCUG should be performed in infants with UTI despite both normal renal sonography and normal DMSA renal scans.

• Childhood Kidney Diseases
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• v.12 no.1
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• pp.62-69
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• 2008

Purpose: The most concerning issue in children with urinary tract infection(UTI) is the probability of underlying genitourinary anomalies and vesicoureteral reflux (VUR), which is frequently associated with renal scarring and eventually end-stage renal disease. Therefore, voiding cystourethrography(VCUG) is usually recommended at the earliest convenient time for children with UTI. However, VCUG is an invasive procedure that requires catheterization and exposure to X-ray. In this study, we aimed to determine the predictability of clinical, laboratory and imaging parameters for VUR in children with UTI. Methods: Data of children with bacteriologically proven UTI who underwent VCUG were evaluated retrospectively for clinical(age, gender, fever), laboratory(leukocytosis, ESR, CRP, pyuria, blood urea nitrogen, serum creatinine) and imaging(renal ultrasound and DMSA renal scan) findings. First, children with UTI were divided into two groups according to the presence of VUR as non-VUR group and with VUR group, and clinical, laboratory variables were compared between these groups. Second, patients who had VUR were reclassified as low-grade VUR(grade I-II) group and high-grade(grade III-V) VUR group according to grading of VUR, and clinical, laboratory and imaging variables were compared between these groups. Results: Among 410 children with UTI, 137 had VUR and 78 high-grade VUR. Fever, leukocytosis, ESR, CRP, pyuria were associated with VUR. In addition, abnormal findings of ultrasonography and DMSA renal scan were closely related to VUR. However, these clinical and laboratory variable in patients with high grade VUR were not different significantly, compared to those with low-grade VUR group. Conclusion: Fever, leukocytosis, ESR, CRP seems to be potentially useful predictors of VUR in pediatric patients with UTI. In addition, renal ultrasonography and DMSA renal scan findings supported the presence of VUR. Further study of these findings could limit unnecessary VCUG in patients with UTI.

• Clinical and Experimental Pediatrics
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• v.56 no.5
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• pp.218-223
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• 2013

Purpose: Early diagnosis and treatment of acute pyelonephritis in children is of special importance in order to prevent serious complications. This study was conducted to determine the diagnostic value of serum interleukin (IL)-6 and IL-8 in children with acute pyelonephritis. Methods: Eighty-seven patients between 1 month to 12 years old with urinary tract infection (UTI) were divided into 2 groups based on the result of 99m-technetium dimercapto-succinic acid renal scan: acute pyelonephritis (n=37) and lower UTI (n=50) groups. White blood cell (WBC) count, neutrophil (Neutl) count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) concentration, platelet count, and serum IL-6 and IL-8 concentrations of both groups were measured and compared. Results: There was a significant difference between two groups regarding WBC count, Neutl count, ESR, and CRP concentration (P<0.05). In addition, the difference between the two groups regarding serum IL-6 and IL-8 concentrations was not significant (IL-6, 60 and 35.4 pg/mL and IL-8, 404 and 617 pg/mL, respectively). The sensitivity and specificity of serum IL-6 and IL-8 for diagnosis of acute pyelonephritis were 73%, 42% and 78%, 32%, respectively. Sensitivity, specificity, negative and positive predictive values of serum IL-6 and IL-8 were less than those of acute phase serum reactants such as CRP. Conclusion: This study showed that there was no significant difference between acute pyelonephritis and lower UTI groups regarding serum IL-6 and IL-8 levels. Therefore, despite confirming results of previous studies, it seems that IL-6 and IL-8 are not suitable markers for differentiating between acute pyelonephritis and lower UTI.

• Childhood Kidney Diseases
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• v.1 no.1
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• pp.46-52
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• 1997

Urinary tract infection (UTI) in children has been known to be a cause of renal damage, leading to scar formation, hypertension and renal failure. And vesico-ureteral reflex (VUR), frequently accompanying UTI in young children, has been incriminated as the main factor causing scar formation. This retrospective study has been undertaken to see the relationship among UTI, VUR and renal scar formation. Study population consisted of 291 children (boy 134, girl 42) with UTI, who have been admitted to the Pediatric Department of Kyungpook University Hospital during 6 1/2 year period from January 1990 to June 1996. VUR was diagnosed by VCUG and renal scar by ultrasonogram, DMSA scan (or DMSA SPECT) and IVP. The following result were obtained. Sexual difference showed male predominance (male to female, 134:42) below 1 year of age, and female predominance (male to female, 11:35) over 5 years of age were rioted. VUR has been found in 64 children (22%) and the degree of reflux, classfied by the method proposed by 'International Reflux Study in Children', were as follows ; Grade I : 4.0%, Grade II : 3.0%, Grade III : 2.7%, Grade IV : 5.8% and Grade V : 6.2%. There was no sexual difference E.coli was the most predominant infecting agent occurring in 167 children (57%), and end-stage renal failure was diagnosed at the time of first admission in 5 children with Grade V VUR. Renal scar has been noted in 49 out of 582 kidneys (8.4%), and the incidence of scar foramation according to the degree of VUR were as follow ; Grade 0 (No reflux) : 1.2%, Grade I : 6.7%, Grade II 27.3%, Grade III 29.4%, Grade IV : 57.1%, and Grade V : 100%. In summary, present study shows that renal scar formation in UTI has close correlation with the severity of VUR occurring more frequently in severe reflux, so that early diagnosis and proper treatment of UTI and VUR is of paramount importance in preventing renal damage in children with UTI.

• Childhood Kidney Diseases
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• v.11 no.2
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• pp.203-211
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• 2007

Purpose : We attempted to compare the independent factors such as age, sex, C-reactive protein(CRP), and white blood cell count(WBC) in children with radiologic studies and assess the necessity of performing voiding cystourethrography(VCUG). Method : 98 children who have been diagnosed their first time febrile urinary tract infection from Janurary 2002 to Januray 2005 were enrolled. In all patient, the duration of fever which occurred before and after treatment was recorded, and CRP, WBC, $^{99m}Tc$-2,3-dimercaptosuccinic acid($^{99m}Tc$-DMSA) renal scans, renal ultrasound and VCUG were analyzed. Results : Of the 98 children diagnosed with urinary tract infection(UTI), 52 were male and 46 were female. 18 had abnormalities in VCUG, 17 had abnormalities in kidney ultrasound, and 20 had partial defects or diffuse uptake decrease in $^{99m}Tc$-DMSA renal scans. There were no significant relationship between incidence of radiologic abnormalities and age. The risk of renal scar was significantly higher in children who had a longer febrile period before treatment than in those with shorter period. Both CRP and WBC were significantly elevated in children with the radiological abnormalities. A positive of $^{99m}Tc$-DMSA renal scans and renal ultrasound were highly associated with vesicoureteral reflux(VUR). Conclusion : If there are abnormalities in the kidney ultrasound and $^{99m}Tc$-DMSA renal scan of a child with initial UTI, a VCUG is recommended. Even in cases without abnormal findings in $^{99m}Tc$-DMSA renal scan and renal ultrasound, clinical data such as CRP and WBC should be assessed, and VCUG should be Performed for the undetected VUR.

• Clinical and Experimental Pediatrics
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• v.49 no.3
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• pp.278-286
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• 2006

Purpose : Although suprapubic bladder aspiration(SBA) is the most reliable technique for identifying bacteriuria in young infant, no report has been published about the clinical manifestations of urinary tract infection(UTI) diagnosed by aspirated urine in Korea. This study was performed to examine clinical manifestations and related factors of UTI confirmed by a positive urine culture obtained by SBA in young infants. Methods : We reviewed medical records of 159 infants younger than six months of age, who had been admitted for UTI to Korea University Ansan Hospital from January 2002 to June 2005. Results : The male:female ratio was 5.1 : 1. The most common pathogen in urine culture was Escherichia coli(92.5 percent). Most of the gram-negative pathogens had high sensitivity to amikacin, or third generation cephalosporins and had low sensitivity to ampicillin, trimethoprim-sulfamethoxazole, or gentamicin. Hydronephrosis and vesicoureteral reflux(VUR) were present in 32.7 percent and 27.7 percent respectively. Renal cortical defects observed on DMSA scans were detected in 37.1 percent. Prolonged fever duration and hospital day, high erythrocyte sedimentation rate(ESR) and C-reactive protein(CRP) levels, hydronephrosis and VUR were related to the renal cortical defects(P<0.05). Rates of UTI-associated bacteremia and aseptic meningitis were 8.3 percent and 6.6 percent. Conclusion : Early differential diagnosis is very important in infants younger than 6 months of age with UTI because the clinical findings are non-specific and UTI-associated bacteremia and aseptic meningitis are concomitantly found. Because prolonged fever and higher ESR and CRP levels are risk factors of the renal cortical defects, radiologic evaluations and nephrologic follow-up were needed in identifying the predisposing congenital abnormalities and chronic renal scarring.

• Pediatric Infection and Vaccine
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• v.17 no.1
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• pp.16-22
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• 2010

Purpose : We aimed to investigate the clinical and phylogenetic characteristics of Escherichia coli Urinary Tract Infections (E. coli UTI). Methods : We enrolled patients with culture-proven E. coli UTI, who were admitted at the study hospital from September 2008 to August 2009. We investigated clinical data of patients with E. coli UTI and characteristics of isolated E. coli strains. The phylogenetic groups were classified using triplex polymerase chain reaction (PCR), and the distribution of nine virulent genes was determined by multiplex PCR. Results : A total of 47 patients have participated in this study. Thirty (63.8%) were under 6 months; eight (17.0%) were between 6-12 months; and nine (19.1%) were over 12 months. We compared two age groups between under 6-month and over 6-month. In the age group under 6-month, higher proportion of male (P =0.002) and group B2 strains (P =0.020) were observed. In contrast, higher proportion of female and group non-B2 strains were observed in age group over 6-month. Frequencies of papC, papGII, papGIII, sfa/foc, hlyC, cnf1, fyuA, iroN and iucC were estimated as 68.1%, 57.4%, 42.6%, 46.8%, 46.8%, 31.9%, 87.2%, 48.9% and 63.8%, respectively. In the comparison of phylogenetic groups, group B2 showed higher distribution of virulent genes, while group D included more strains resistant to trimethoprim/sulfamethoxazole (TMP/SMZ) than other groups. Conclusion : We showed the age group-specific difference in the distribution of sex ratios and phylogenetic groups; more male and group B2 strains in age group under 6-month, while more female and group non-B2 in age group over 6-month. However, further evaluation including larger number of patients will be necessary to confirm above thesis in future molecular epidemiological studies.

• Pediatric Infection and Vaccine
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• v.17 no.2
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• pp.74-82
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• 2010

Purpose : The Dipslide culture test is a rapid method for diagnosis of urinary tract infection (UTI). The aim of this study is to determine the diagnostic availability of a urine Dipslide test for evaluation of UTI in febrile children. Methods : Urine specimens from 151 febrile infants were inoculated by a routine blood agar urine culture method and the Dipslide test at the same time. Following incubation for 16-24 hours, the results of the Dipslide test were read at the next visit. Both results of Dipslide and those of routine culture were compared. Results : The mean age of subjects was 15${\pm}$10.6 months. There were 150 infants (99.3%) who had fever with a mean duration of 2.6${\pm}$2.6 days. Thirty two infants (21.2%) were diagnosed as having UTI. Sensitivity and specificity of Uricult Trio CLED medium were 59.4% and 84.8%, respectively. Sensitivity and specificity of Uricult Trio E. coli medium were 60.0% and 96.2%, respectively. The Pearson correlation coefficient between results of Uricult Trio CLED medium and urine culture was 0.438 (P=0.01). Correlation between results of Uricult Trio E. coli medium and urine culture was 0.617 (P=0.01). Conclusion : The Dipslide test requires only 16-24 hours with high specificity in terms of UTI caused by E. coli without the problems associated with specimen delay. This test seems to be helpful for exclusion of UTI in febrile infants and it may reduce unnecessary hospitalization and antibiotic use. However, further studies are required before the product can be recommended as a routine diagnostic tool.

• Childhood Kidney Diseases
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• v.11 no.2
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• pp.229-238
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• 2007

Purpose : Since the first febrile UTI(urinary tract infection) in infants is commonly associated with vesicoureteral reflux(VUR), imaging studies such as renal ultrasonography, dimercaptosuccinic acid(DMSA) scan, and voiding cystourethrography(VCUG) are recommended. How-ever, because of the invasiveness of VCUG, it is difficult to perform in all young infants with febrile UTI. The purpose of this study is to compare the clinical and laboratory characteristics, radiologic findings between the young infant group(1 to 6month, n=121) and the old infant group(7 to 24months, n=91), and to determine the clinical and radiologic risk factors that predict the presence of VUR before the VCUG in patients with their first febrile UTI under 2 years of age. Methods : We reviewed the medical records of 211 first febrile UTI patients under 2 years of age retrospectively, and compared clinical, laboratory, and radiologic findings between the two age groups. Results : The young infant group had a male preponderance and a higher incidence of Escherichia coli in their urine culture. The incidence of acute renal parenchymal defects on DMSA scans were significantly increased in the young infant group. The incidence of VUR was 29% in patients who had a VCUG, but there were no differences in the incidence of VUR between the two age groups. Abnormal findings on DMSA scan significantly correlated with higher incidence of VUR in the young infant group. Incidence of abnormal findings DMSA scan significantly increased with high grade VUR(garde III-V ). Conclusion : In treating first febrile UTI patients under 2 years, physicians have to consider such characteristics as age less than 6 months, male preponderance, E.coli in the urine culture, and increased incidence of abnormal findings on DMSA scans which correlated well with the presence of VUR. The results of the DMSA scan might help us to predict the presence of VUR before the VCUG in first febrile UTI and help us to reduce performing invasive radio-logic studies especially in the young infant group. (J Korean Soc Pediatr Nephrol 2007;11:229-238)