• Childhood Kidney Diseases
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• 제21권2호
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• pp.128-135
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• 2017

Purpose: Extended-spectrum ${\beta}$-lactamase-producing bacteria-induced urinary tract infections are increasing and require more potent antibiotics such as carbapenems. We evaluated the clinical significance of extended-spectrum ${\beta}$-lactamase -urinary tract infection in children younger than 5 years to select proper antibiotics and determine prognostic factors. Differences were compared between age groups. Methods: We retrospectively studied 288 patients with their first febrile urinary tract infection when they were younger than 5 years. Patients were divided into extended-spectrum ${\beta}$-lactamase-positive and extended-spectrum ${\beta}$-lactamasenegative urinary tract infection groups. Clinical characteristics and outcomes were compared between the groups; an infant group was separately analyzed (onset age younger than 3 months). Results: Extended-spectrum ${\beta}$-lactamase urinary tract infection occurred in 11 % patients who had more frequent previous hospitalization (P=0.02) and higher recurrence rate (P=0.045). During the antimicrobial susceptibility test, the extended-spectrum ${\beta}$-lactamase-positive urinary tract infection group showed resistance to third-generation cephalosporins; however, 98% patients responded clinically. In the infant group, extended-spectrum ${\beta}$-lactamase-positive urinary tract infection occurred in 13% patients and was associated with a longer pre-onset hospitalization history (P=0.002), higher C-reactive protein level (P=0.04), and higher recurrence rate (P=0.02) than that in the older group. Conclusion: Extended-spectrum ${\beta}$-lactamase urinary tract infection requires more attention because of its higher recurrence rate. The antimicrobial susceptibility test demonstrated resistance to third-generation cephalosporins, but they can be used as first-line empirical antibiotics because of their high clinical response rate. Aminoglycosides can be second-line antibiotics before starting carbapenems when third-generation cephalosporins do not show bactericidal effects for extended-spectrum ${\beta}$-lactamase urinary tract infection.

• Childhood Kidney Diseases
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• 제19권2호
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• pp.125-130
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• 2015

Introduction: This study investigated whether renal and bladder ultrasonography (RBUS) findings performed in children with the first incidence of febrile urinary tract infection (UTI) can predict UTI recurrence, high-grade vesicoureteral reflux (high-grade VUR), or acquired renal scarring (aRS). Methods: In all, 917 children who were admitted to our hospital from January 2001 to October 2010, owing to the first incidence of febrile UTI were enrolled in this study. All children underwent RBUS during admission. The mean follow-up was 7.9 months (standard deviation $[SD]{\pm}13.3$). UTI recurrence rates were calculated according to various clinical parameters. By using bivariate and multiple logistic regression analyses, we determined whether age, sex, abnormal RBUS findings, abnormal dimercaptosuccinic acid renal scan findings, or RBUS findings parameters were predictive of UTI recurrence, high-grade VUR, or aRS. Results: On RBUS, hydronephrosis and congenital anomaly of the kidney and urinary tract significantly predicted UTI recurrence. A small kidney, hydroureter, hydronephrosis, cortical thinning, and increased parenchymal echogenicity significantly predicted high-grade VUR. However, their odds ratios (OR) are low compared to normal RBUS findings (recurrent UTI: OR 0.432 and 0.354 vs. 0.934, respectively, high-grade VUR: .019, 0.329, 0.126, 0.058, and 0.188 vs. 2.082, respectively). No RBUS findings significantly predicted aRS. Recurrent UTI, high-grade VUR, and abnormal RBUS findings significantly predicted aRS (OR of 4.80, 4.61, and 2.58, respectively). Conclusion: RBUS is necessary to exclude severe congenital renal scarring, obstructive uropathy, and renal abscess at the first incidence of febrile UTI and is helpful in determining the need for subsequent clinical imaging.

• Clinical and Experimental Pediatrics
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• 제58권9호
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• pp.341-346
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• 2015

Purpose: To evaluate the practical applications of the diagnosis algorithms recommended by the American Academy of Pediatrics urinary tract infection (UTI) guideline. Methods: We retrospectively reviewed the medical records of febrile UTI patients aged between 2 and 24 months. The patients were divided into 3 groups: group I (patients with positive urine culture and urinalysis findings), group II (those with positive urine culture but negative urinalysis findings), and group III (those with negative urine culture but positive urinalysis findings). Clinical, laboratory, and imaging results were analyzed and compared between the groups. Results: A total of 300 children were enrolled. The serum C-reactive protein level was lower in children in group II than in those in groups I and III (P<0.05). Children in group I showed a higher frequency of hydronephrosis than those in groups II and III (P<0.05). However, the frequencies of acute pyelonephritis (APN), vesicoureteral reflux (VUR), renal scar, and UTI recurrence were not different between the groups. In group I, recurrence of UTI and presence of APN were associated with the incidence of VUR (recurrence vs. no recurrence: 40% vs.11.4%; APN vs. no APN: 23.3% vs. 9.2%; P<0.05). The incidence of VUR and APN was not related to the presence of hydronephrosis. Conclusion: UTI in febrile children cannot be ruled out solely on the basis of positive urinalysis or urine culture findings. Recurrence of UTI and presence of APN may be reasonable indicators of the presence of VUR.

• Clinical and Experimental Pediatrics
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• 제61권1호
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• pp.17-23
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• 2018

Purpose: To determine the relationship between vaginal reflux (VR) and urinary tract infection (UTI) in female children aged <36 months. Methods: A single center retrospective study was performed for 191 girls aged <36 months, with a diagnosis of febrile UTI, who underwent a voiding cystourethrography (VCUG) for assessment of vesicoureteral reflux (VUR) at Sanggye Paik Hospital. Fifty-one girls, who underwent VCUG for assessment of congenital hydronephrosis or renal pelvis dilatation, without a UTI, formed the control group. The correlation between the presence and grade of VR and UTI was evaluated. Results: The prevalence rate of VR was higher in the UTI (42.9%) than control (13.7%) group (P<0.05), with a higher VR severity grade in the UTI (mean, 0.64) than control (mean, 0.18) group (P<0.05). On subanalysis with age-matching (UTI group: n=126, age, $5.28{\pm}2.13months$; control group: n=22, age, $4.79{\pm}2.40months$; P=0.33), both VR prevalence (43.65% vs. 18.18%, P<0.05) and grade (0.65 vs. 0.22, P<0.05) remained higher in the UTI than control group. Presence and higher grade of VR were associated with UTI recurrence (P<0.05). VR was correlated to urosepsis (P<0.05). The renal defect rate of patients with VR (VR [+]/VUR [+]) was not different from that of patients without VR (74% vs. 52%, P=0.143) in the VUR group; however, it was higher than that of VR (+)/VUR (-) patients (74% vs. 32%, P=0.001). If a child with VR (+)/VUR (+) is exposed to a UTI, the risk of renal defect increases. Conclusion: Occurrence of VR is associated with UTI recurrence and urosepsis in pediatric female patients.

• Clinical and Experimental Pediatrics
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• 제46권6호
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• pp.561-565
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• 2003

목 적 : 요로 감염은 진단 및 치료가 일찍 이루어지지 않으면 심한 신장 손상을 일으킬 수 있는 질환이고 재발 역시 잦은 질환이므로 미리 재발이 예방된다면 신장의 손상을 줄일 수 있을 것이다. 저자들은 요로 감염의 재발에 영향을 주는 위험인자를 분석하여 위험성이 높은 환아들을 조기에 선별하여 재발을 조기에 진단함으로 손상을 줄이는데 도움을 주고자 본 연구를 시행하였다. 방 법 : 2000년 1월부터 2001년 12월까지 고려대학교 구로병원 소아과에서 요로 감염으로 치료받은 환아 168명 중에 6개월 이상 추적 관찰한 93명을 대상으로 하였으며 의무 기록지를 바탕으로 후향적 조사를 하였다. 요로 감염의 재발을 진단하기 위해 매달 소변 배양 검사를 실시하였다. 결 과 : 총 재발률은 32.3%로 남아에서는 37.1%였고 여아에서는 17.4%였다(P<0.05). 요로 감염시의 원인균으로는 초발이나 재발에 모두 E.coli가 가장 많았다. 재발 감염이 있는 남아의 초발 감염은 재발이 없는 남아보다 발병 시기가 빨랐다($4.8{\pm}1.0$개월 대 $16.5{\pm}3.8$개월, P<0.05). 첫 감염 후 첫 6개월내에 약 77% 정도에서 재발을 하였는데 남아에서의 첫 감염 후 재발이 여아에서의 재발보다 빨랐다($3.7{\pm}0.6$개월 대 $14{\pm}8.2$개월, P<0.05). 1세 미만에 요로 감염이 발병한 환아에 있어 재발 횟수는 연간 $0.69{\pm}0.8$회로 1세 이상에서 요로 감염이 발병한 환아의 재발 횟수인 연간 $0.16{\pm}0.4$회보다 의의있게 높았으며 구조적인 이상 유무가 재발에 미치는 영향은 없었다. 결 론 : 요로 감염의 재발에 대한 위험인자로는 성별과 연령이 중요하게 생각되며 남아인 경우, 1세 미만인 경우가 이에 해당한다. 그러므로 특히 이런 환아들에서는 정기적으로 매달 소변 배양 검사를 감염 후 적어도 첫 6개월 꼭 시행하는 것이 바람직하다. 예방적 항생제 요법을 하는 경우에 방광 요관 역류는 재발의 위험인자로 생각되지는 않으며 따라서 방광 요관 역류가 있는 경우에는 예방적 항생제 요법을 시행하여야 할 것이다.

• Childhood Kidney Diseases
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• 제21권2호
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• pp.94-100
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• 2017

Purpose: The American Academy of Pediatrics provides guidelines for managing febrile urinary tract infection (UTI) in infants and children 2-24 months old, but little guidance is offered regarding UTIs in those younger than 8 weeks of age. The definition of UTI is unclear and whether to proceed with micturating cystourethrography (MCUG) or $^{99m}$technetium-dimercaptosuccinic acid (DMSA) scintigraphy scan in this age group is controversial. Methods: We retrospectively analyzed 29 neonates and infants younger than 2 months of age who underwent late DMSA scans 9 months following the first episode of febrile or symptomatic UTI between July 2009 and June 2016. Results: In total, 192 children aged 0-24 months underwent ultrasound and DMSA scans (MCUG in 174/192). Neonates and infants younger than 2 months of age were significantly less likely to develop fever, and had a lower fever peak, shorter duration of fever before admission and after starting antibiotics, longer hospitalization period, lower C-reactive protein, and greater incidence of nonEscherichia coli infection. There was no difference in pyuria response at diagnosis. The prevalence rates of an ultrasound abnormality (28%), vesicoureteral reflux (28%), UTI recurrence (38%), and renal scarring (10%) in infants younger than 8 weeks of age were similar to those in children 2-24 months old. Conclusion: Neonates and infants younger than 2 months of age with UTI warrant special consideration because the fever response used for diagnosis in older children may be absent or blunted. Clinical guideline is needed for the diagnosis and management of UTI in this age group.

• Childhood Kidney Diseases
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• 제21권2호
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• pp.136-141
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• 2017

Purpose: This study aimed to investigate clinical and radiological factors that may predict high-grade vesicoureteral reflux (VUR) in patients with febrile urinary tract infection (UTI). Methods: We retrospectively analyzed medical records of 446 patients diagnosed with febrile UTI from March 2008 to February 2017. All patients underwent renal-bladder ultrasonography (RBUS), 99mTc dimercaptosuccinic acid (DMSA) renal scan, and voiding cystourethrography (VCUG), and were divided in to 3 groups: a high-grade VUR group (n=53), a low-grade VUR group (n=28), and a group without VUR (n=365). Results: The recurrence and non-Escherichia coli infection rates in febrile UTI were significantly higher in the high-grade VUR group than in the other two groups (P<0.05). RBUS showed that hydronephrosis and ureter dilatation were more frequent in the high-grade VUR group than in the other groups (P<0.05). In the high-grade VUR group, a renal cortical defect was more likely to appear as multiple defects, and the difference in bilateral renal scan uptake between both kidneys was larger than in the other two groups (P<0.001). Conclusion: Recurrent UTI, non-E. coli UTI, abnormal findings on RBUS such as hydronephrosis and ureter dilatation, and abnormal findings in the DMSA renal scan such as multiple renal cortical defects and greater uptake difference were associated with high-grade VUR. VCUG should be selectively performed when RBUS and/or DMSA renal scan reveal significant abnormalities.

• Childhood Kidney Diseases
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• 제26권1호
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• pp.52-57
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• 2022

Purpose: To determine predictive factors for detecting renal parenchymal damages (RPDs) in infants with recurrent febrile urinary tract infection (fUTI). Methods: From January 2015 to December 2021, 102 infants with recurrent fUTI and who underwent ^99mTc-dimercaptosuccinic acid (DMSA) renal scan in our hospital were included in this study. Controls included infants with normal DMSA results performed 3 months apart from the 2nd episode of fUTI. DMSA-positive group included infants with positive DMSA results performed 3 months apart from the 2nd episode of fUTI or at the 3rd episode of fUTI. The recurrence rate, causative bacteria, renal size discrepancy of both kidneys, and laboratory findings including C-reactive protein (CRP) and spot urine sodium-to-potassium ratio (uNa/K) were compared between both groups. Results: Only 3.8% of 79 infants with a 2nd episode of fUTI showed positive DMSA results. fUTI recurred more frequently within 12 months of follow-up in the DMSA-positive group than in the control group (69% vs. 13%, P<0.001). CRP values were significantly higher in the DMSA-positive group than in the control group (7.3 mg/dL vs. 3.7 mg/dL, P<0.001). Spot uNa/K were significantly lower in the DMSA-positive group than in the control group (0.6 vs. 1.1, P<0.001). Conclusions: Congenital renal scar and RPDs on the DMSA scan were more frequently found in infants with recurrent fUTI than those in the control group. High CRP values and low spot uNa/K in acute infections were helpful in predicting the presence of RPD in infants with recurrent fUTI.

• Childhood Kidney Diseases
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• 제19권1호
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• pp.31-38
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• 2015

Purpose: We evaluated the long-term results of endoscopic Deflux$^{(R)}$ injection for treating vesicoureteral reflux (VUR) in children. Methods: Between September 2004 and September 2014, 243 children (137 boys and 106 girls) with a mean age of 53 months underwent Deflux$^{(R)}$ injection. Our clinical protocol included radionuclide voiding cystography (RNC) at postoperative 3 months, 1 year and 3 years to assess the VUR resolution. Results: The cure rates at 3 months, 1 year, and 3 years by patients were 70.8%, 64.3%, and 65.6% for the total patients and 79.2%, 75.2%, and 76.4%, for the ureters, respectively. The recurrence rate of postoperative febrile urinary tract infection (UTI) was 20% in patients without VUR at postoperative 1 year. Twenty patients undergoing ureteroneocystostomy (UNC) significantly had younger age (P=0.003), higher VUR grade (P<0.001), and lower success rates of Deflux$^{(R)}$ injection (P<0.05). On univariate analysis, older age (P=0.014) and lower grade of VUR (P=0.031) were the significant predictors of a successful outcome. But there was none on multivariate analysis. Younger age, especially age of 0-12 month-old, was the only significant predictor of postoperative febrile UTI recurrence on both univariate and multivariate analysis. Conclusion: Deflux$^{(R)}$ injection is efficacious with a low complication rate for the anti-reflux procedure in children. There is low recurrence rate of UTI though VUR persists, and high probability of no VUR at 3 years if no VUR at 1 year. It is recommendable not to perform follow-up RNC at 3 years routinely if no VUR at 1 year.

• Clinical and Experimental Pediatrics
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• 제64권6호
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• pp.293-300
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• 2021

Background: Understanding the epidemiology and prevalence of febrile urinary tract infection (fUTI) in children is important for risk stratification and selecting appropriate urine sample collection candidates to aid in its diagnosis and treatment. Purpose: This study aimed to analyze the epidemiology, etiology, and changes in antibiotic susceptibility patterns of the first fUTI in children. Methods: This retrospective observational cohort study included children younger than 19 years of age who were diagnosed and treated for their first fUTI in 2006-2016. Electronic medical records were analyzed and radiologic images were evaluated. Results: A total of 359 patients (median age, 5.1 months; interquartile range, 3.0-10.5 months) fit the inclusion criteria; of them, 78.0% (n=280) were younger than 12 months old. The male to female ratio was 5.3:1 for patients aged 0-2 months, 2.1:1 for those 3-5 months, and 1.6:1 for those 6-11 months. Beyond 12 months of age, there was a female predominance. Escherichia coli was the leading cause (83.8%), followed by Enterococcus species (6.7%), and Klebsiella pneumoniae (3.6%). Significant yearly increases in the proportions of multidrug-resistant strains (P<0.001) and extended-spectrum beta-lactamase (ESBL) producers (P<0.001) were observed. In patients with vesicoureteral reflux (VUR), the overall recurrence rate was 53.6% (n=15). A significantly higher recurrence rate was observed when the fUTI was caused by an ESBL versus non-ESBL producer (75.0% vs. 30.0%, P=0.03). Conclusion: fUTI was most prevalent in children younger than 12 months of age and showed a female predominance in patients older than 12 months of age. The proportion of ESBL producers causing fUTI is increasing. Carbapenems, rather than noncarbapenems, should be considered for treating fUTI caused by ESBL-producing enteric gram-negative rods to reduce short-term recurrence rates in children with VUR.