Urinary tract infection in pediatrics: an overview / Infecção do trato urinário em pediatria: uma visão geral

Abstract Objective This review aimed to provide a critical overview on the pathogenesis, clinical findings, diagnosis, imaging investigation, treatment, chemoprophylaxis, and complications of urinary tract infection in pediatric patients. Source of data Data were obtained independently by two authors, who carried out a comprehensive and non-systematic search in public databases. Summary of findings Urinary tract infection is the most common bacterial infection in children. Urinary tract infection in pediatric patients can be the early clinical manifestation of congenital anomalies of the kidney and urinary tract (CAKUT) or be related to bladder dysfunctions. E. coli is responsible for 80-90% of community-acquired acute pyelonephritis episodes, especially in children. Bacterial virulence factors and the innate host immune systems may contribute to the occurrence and severity of urinary tract infection. The clinical presentation of urinary tract infections in children is highly heterogeneous, with symptoms that can be quite obscure. Urine culture is still the gold standard for diagnosing urinary tract infection and methods of urine collection in individual centers should be determined based on the accuracy of voided specimens. The debate on the ideal imaging protocol is still ongoing and there is tendency of less use of prophylaxis. Alternative measures and management of risk factors for recurrent urinary tract infection should be emphasized. However, in selected patients, prophylaxis can protect from recurrent urinary tract infection and long-term consequences. According to population-based studies, hypertension and chronic kidney disease are rarely associated with urinary tract infection. Conclusion Many aspects regarding urinary tract infection in children are still matters of debate, especially imaging investigation and indication of antibiotic prophylaxis. Further longitudinal studies are needed to establish tailored approach of urinary tract infection in childhood.

Resumo Objetivo Esta revisão teve como objetivo fornecer uma visão crítica da patogênese, achados clínicos, diagnóstico, investigação por imagem, tratamento, quimioprofilaxia e complicações da infecção do trato urinário em pacientes pediátricos. Fonte de dados Os dados foram obtidos de forma independente por dois autores que fizeram uma pesquisa abrangente e não sistemática em bancos de dados públicos. Síntese dos achados A infecção do trato urinário é a infecção bacteriana mais comum em crianças. Em pacientes pediátricos, pode ser a manifestação clínica precoce de anomalias congênitas do rim e trato urinário (CAKUT) ou estar relacionada a disfunções da bexiga. A E. coli é responsável por 80-90% dos episódios agudos de pielonefrite adquirida na comunidade, principalmente em crianças. Os fatores de virulência bacteriana e o sistema imunológico inato do hospedeiro podem contribuir para a ocorrência e gravidade da infecção do trato urinário. A apresentação clínica de infecções do trato urinário em crianças é altamente heterogênea, com sintomas que podem ser bastante obscuros. A cultura de urina ainda é o padrão-ouro para o diagnóstico de infecção do trato urinário e os métodos de coleta de urina em centros individuais devem ser determinados com base na precisão das amostras coletadas. O debate sobre o protocolo de imagem ideal ainda está em andamento e há uma tendência a um menor uso da profilaxia. Medidas opcionais e o manejo dos fatores de risco para infecção do trato urinário recorrente devem ser enfatizados. Entretanto, em pacientes selecionados, a profilaxia pode proteger contra infecção do trato urinário recorrente e consequências em longo prazo. Segundo estudos populacionais, hipertensão e doença renal crônica raramente são associadas à infecção do trato urinário. Conclusão Muitos aspectos relacionados à infecção do trato urinário em crianças ainda são motivo de debate, principalmente a investigação por imagem e a indicação de profilaxia com antibióticos. Estudos longitudinais adicionais são necessários para estabelecer uma abordagem personalizada da infecção do trato urinário na população pediátrica.

Fungoma vesical por Candida tropicalis: un caso clínico pediátrico / Bladder fungus ball by Candida tropicalis: a pediatric case report

Vesical fungus ball is a mobile, oval and echogenic mass as a result of accumulation of long and wide numerous hyphae. Fungal urinary tract infection incidence has increased notoriously and there are isolated yeast in 7 to 8% of urine cultures. Different species of Candida are cause of urinary tract infection. Epidemiologically, the first isolated pathogen is Candida albicans, followed by Candida tropicalis. Bladder poll has been documented as the most important risk factor for candiduria in critical patients into intensive care.

Un fungoma vesical es una masa móvil, oval y ecogénica en la vejiga resultante del acúmulo de hifas largas y anchas. La incidencia de la infección urinaria de etiología fúngica se ha incrementado notablemente. Se aíslan levaduras en 7 a 8% de los urocultivos. Diferentes especies de Candida son causantes de infección urinaria, siendo Candida albicans la más frecuente, seguida de Candida tropicalis. Presentamos el caso de un niño varón de cuatro años, con un síndrome de Guillain Barré, catéter urinario permanente, estadía prolongada en UCI y expuesto a tratamiento antibacteriano de amplio espectro que desarrolló un fungoma vesical, diagnosticado por ecotomografía, con aislamiento de C. tropicalis en orina. Se trató con anfotericina B deoxicolato y extracción del fungoma por cistoscopia, con buena respuesta clínica. El cateterismo vesical se ha documentado como el factor de riesgo más importante para candiduria en pacientes de terapia intensiva.

Clinical features and impact factors of simple renal cysts / 中国综合临床

Objective To analyze the main clinical features and impact factors of simple renal cyst (SRC), and to provide evidence for the future prevation and cure of simple renal cysts.Methods In this crosssectional study,a total number of 91 433 participants(aged 18-98 years old) were included who underwent health examinations during 2012-2014.The main life styles and clinical features of each participants were recored,and blood biochemistry test, urinanalysis and renal ultrasonography were performed.Results The prevalence of SRC was 2.70％ (2 465 subjects were diagnosed by ultrasonography).It was higher in men than women(2.95％ vs.1.68％, P =0.00), which was increased with the increasing of age (respectively 0.37％, 0.57％, 1.30％ ,2.69％ ,4.46％ and 6.91％ in the group of ≤29year,30-39 year,40-49 year,50-59 year,60 -69 year and ≥70 year,P＜0.01).The maximum diameter of simple renal cysts were (2.6±1.7) cm.Age,rate of men, body mass index, glucose, total cholesterol, creatinine, urea nitrogen, and urinary protein positive rate, kidney stone prevalence were higher in SRC group(respectively (61.11±11.24)year vs.(51.37±13.72) year, 87.59％ vs.79.88％, (25.27 ± 3.19) kg/m2 vs.(24.97 ± 3.35) kg/m2, (6.09 ± 2.08) mmol/L vs.(5.70 ± 1.85) mmol/L, (5.11 ± 1.54) mmol/L vs.(5.02 ± 1.37) mmol/L, (90.71 ± 34.84) μmol/L vs.(80.72 ±28.04) μmol/L, (6.03±3.60) mmol/L vs.(5.55±5.15) mmol/L,7.46％ vs.4.25％ ,7.06％ vs.1.28％ ,P ＜0.01) ,but glomerular filtration rate, triglycerides, rate of like salty, drink, smoke was lower than the group withoutSRC((79.01±19.89) ml/(min· 1.73 m2) vs.91.74±21.8 ml/(min · 1.73 m2),(1.57±1.48) mmol/L vs.(1.69± 1.82) mmol/L, 4.38％ vs.7.94％, 22.68％ vs.30.75％, 24.91％ vs.30.97％;P＜ 0.01).But,there was no difference between these two groups in serum uric acid ((309.16± 85.79) μmol/L vs.(312.38±91.22) μmol/L,P＞0.05).SRC as a dependent variable of multivariate log regression analysis.The result showed the OR of age, gender, fasting blood glucose, urea nitrogen, glomerular filtration rate, positive urine protein,kidney stone were respectively 1.040, 1.862, 1.035, 1.005,0.982, 1.254, 4.526, 95％ CI =1.037 -1.045,1.643-2.110,1.017-1.053,1.000-1.010, 0.980-0.984, 1.068-1.473,3.812-5.374;P ＜0.01).While the OR of multiple SRC was 0.43,95％ CI: 0.210-0.867 (P＜0.05) , when kidney stone as a dependent variable.Conclusion Old-age males are high risk population of catching SRC.Kidney stone and positive urine protein are important risk factors of SRC.Meanwhile kidney stone more easily induce single and small SRC.SRC is a key risk factor to induce renal function decrease.Therefore, GFR is a sensitive index of renal disfunction that induced by SRC.

A Female Infant with Segmental Multicystic Dysplastic Kidney

There have only been 35 pediatric cases and one adult case reported on segmental multicystic dysplastic kidney (MCDK) from our search in PubMed, including 19 cases detected antenatally. There is little documentation of segmental MCDK, particularly concerning its natural history. Segmental MCDK can be presented atypically, making diagnosis more difficult. We report an another case with segmental MCDK. Multicystic abdominal mass detected on antenatal sonogram in this infant was diagnosed as segmental MCDK by renal ultrasonography and computed tomography. If a definitive diagnosis of segmental MCDK can be made on imaging, surgery is not required for a diagnostic biopsy.

Ultrasonographic Findings in Children with Vesicoureteral Reflux

PURPOSE: The aim of this study is to investigate the renal ultrasonographic findings in children with vesicoureteral reflux (VUR). METHODS: We retrospectively reviewed the medical records of 83 patients who were diagnosed with VUR and underwent ultrasonography at Ilsan hospital between January 2000 and December 2010. RESULTS: Among 166 renal units, 108 (65.0%) were found to have vesicoureteral reflux (VUR). Fifty-one (73.9%) had VUR in renal units with abnormal ultrasonography (USG), whereas 57 (58.7%) had VUR in renal units with normal USG. Abnormal USG findings were independent risk factors for VUR (Odds ratio, 1.98; 95% CI, 1.01-3.89; P=0.045). In renal units with VUR, the number of normal USG finding was 52.8%, and the abnormal findings were as follows; increased cortical echogenicity 16.7%, hydronephrosis 17.6%, megaureter or ureter dilatation 8.3%, hydronephrosis and ureter dilatation 1.9%, duplication of ureter 1.9%, and atrophic kidney 0.9%. The prevalence of VUR was relatively higher in renal units with hydronephrosis (23/19, 82.6%), ureter dilatation (9/9, 100%), duplication of ureter (2/3, 66.6%), and atrophic kidney (1/1, 100%). CONCLUSION: Our study indicates that VUR was associated with abnormal USG findings. When there are abnormal USG findings such as hydronephrosis, ureter dilatation, duplication of ureter, and atrophic kidney in children with UTI, VCUG is recommended to detect VUR after controlling UTI.

Clinical Study of Neonatal Pelvicectasia

OBJECTIVE: This study was conducted to investigate the different cause of pelvicectasia and its clinical outcome. The most important management of pelvicectasia consist of the early diagnosis and evaluation of the pathologic abnormalities of congenital pelvicectasia. This will help to offer the guideline on management of neonatal pelvicectasia. METHODS: We examined one hundred and seventy-one live neonates who were hospitalized and diagnosed with pelvicectasia at Soonchunhyang University Cheonan Hospital from January 2008 to December 2008. A retrospective study was carried out in these patients for last three years. Renal ultrasonography was repeated at 1 month after birth and then 3 months interval. Diuretic renal scan with (99m)Tc-labeled diethylenetriamine pentaacetic acid augmented with furosemide and voiding cystourethrogram was done after 4 to 6 weeks of first renal ultrasonography. Patients were followed-up for 1 to 30 months (average, 7.2 months). RESULTS: Pelvicectasia was postnatally detected in 171 cases (33.7%) among 507 neonates. Males were twice than females. Additional imaging studies revealed that normal kidney structure was the most common postnatal diagnosis (97.1%), followed by ureteropelvic obstruction, vesicoureteral reflux, multicystic kidney, ureteric duplication. Spontaneous regression of pelvicectasia was revealed in 165 renal units (67.6%). CONCLUSION: There are many cause of spontaneous regression in mild to moderate pelvicectasia. Urinary tract infection occurs in many neonates with pelvicectasia. Mild to moderate neonatal pelvicectasia without vesicoureteral reflux is clinically much less significant. Accordingly, close observation with serial renal ultrasonography may be sufficient.

1 year follow-up results of prenatally diagnosed unilateral hydronephrosis according to renal sonographic findings at 1 month of age / 소아과

PURPOSE: The natural courses of prenatally diagnosed hydronephrosis(HN) are diverse. Our purpose was to determine if the findings of renal ultrasonography(USG) in patients with prenatal HN at 1 month of age can predict the 1 year follow-up results and determine the guideline of follow-up study. METHODS: Among 462 hydronephrotic patients registered between 1996 and 2004, 153 unilateral hydronephrotic renal units were enrolled in this study, bilateral HN, vesicoureteral reflux and other associated anomaly were excluded. These were classified into four groups respectively, according to anterior posterior pelvic diameter(APPD) or Society for Fetal Urology(SFU) grading by USG findings at 1 month after birth. Renal USG and Tc(99m)-mercaptoacetyl triglycerine(MAG3) scan were done according to a set protocol. RESULTS: Most cases improved or remained stationary. No one underwent an operation SFU grade 1,2 groups and only one case of SFU grade 3 group was operated. Thirty two cases(64 percent) were operated on among the 50 cases of SFU grade 4 group. 0/2(0 percent), 5/11(45.5 percent), 11/17(64.7 percent) and 16/20(80 percent) were operated on in each group with APPD 30 mm, and the operation risk is higher as the APPD is increased. CONCLUSION: In group with SFU grade below 3 and APPD below 10 mm, we can delay the follow-up study beyond existing set protocol. Operations are recommended immediately if diuretic renogram show the obstructive pattern or decreased renal function in SFU grade 4 group with APPD over 10 mm.

Vesicoureteral Reflux and Renal Scar

PURPOSE: Vesicoureteral reflux(VUR) is the major risk factor of urinary tract infection(UTI) in children and may result in serious complications such as renal scarring and chronic renal failure. The purpose of this study was to evaluate the relationship between VUR and renal scar formation, the usefulness and correlation of various imaging studies in reflux nephropathy, and the spontaneous resolution of VUR. METHODS: We retrospectively reviewed 106 patients with VUR with no accompanying urogenital anomalies in the Department of Pediatrics, Bundang CHA Hospital during the period from Jan. 1996 to Mar. 2005. Ultrasonography and 99mTc-dimercaptosuccinic acid(DMSA) scan were performed in the acute period of UTI. Voiding cystourethrography(VCUG) was performed 1 to 3 weeks after treatment with UTI. Follow-up DMSA scan was performed 4 to 6 months after treatment and a follow-up VCUG was performed every 12 months. RESULTS: The mean age at detection of VUR was 13.8+/-22.2 months and the male to female ratio was 2:1. The incidence of renal scarring showed a tendency of direct correlation between severity of VUR(P<0.001) and abnormal findings of renal ultrasonography(P<0.01). 63.2%(24 of 38 renal units) of renal parenchymal defects present in the first DMSA scan disappeared on follow-up DMSA scans. Follow-up DMSA scans detected renal scars in 7(14%) of 50 renal units with ultrasonographically normal kidneys. Meanwhile, ultrasonography did not show parenchymal defects in 7(36.8%) of 19 renal units where renal scarring was demonstrated on a follow-up DMSA scan. The spontaneous resolution rate of VUR was higher(75%) in cases with low grade(I to III) VUR(P<0.01). CONCLUSIONS: The presence and severity of VUR and abnormal findings of renal ultrasonography significantly correlated with renal scar formation. DMSA scan was useful in the diagnosis of renal defects. Meanwhile renal ultrasonography was an inadequate method for evaluating renal parenchymal damage. Therefore, follow-up DMSA scans should be performed to detect renal scars even in children with low-grade VUR and normal renal ultrasonography.

A Clinical Study of Renal Abscesses in Children

PURPOSE: Renal abscess is very rare in children and its diagnosis is difficult because symptoms are often nonspecific. In previous studies, only 15% to 25% of patients were reported to be diagnosed at the time of admission. Early diagnosis and treatment are important because mortality rate correlates positively with the time of diagnosis. The purpose of this study is to clarify the clinical features of children with renal abscess and to investigate the possible indicators of this disease for early diagnosis and proper treatment. METHODS: Twelve children diagnosed with renal abscess from Jan. 1996 to Jul. 2004 were included. The age of patients ranged from 5 months to 15 years. We retrospectively analyzed the demographics of patients, their symptoms, predisposing factors, diagnostic methods and causative organisms and the treatment modalities. RESULTS: Fever was the most common manifestation. Five children(42%) had vesicoureteral reflux. Renal ultrasonography and computerized tomography were the most frequently used imaging tools to detect renal abscess. Gram negative bacteria were isolated in 7 patients and Staphylococcus aureus grew in 2 patients. All patients received intravenous antibiotics and 4 patients underwent aspiration or drainage of renal abscess. The average admission duration was 30 days. CONCLUSION: Renal abscess should be included in the differential diagnosis of prolonged fever in children, especially when flank pain is combined. For early diagnosis and a better prognosis, patients should be promptly investigated with ultrasonography or computerized tomography.

Optimal Timing of Surgery of Hydronephrosis Due to Ureteropelvic Junction Obstruction in Neonates and Infants

PURPOSE: We review our experience with pyeloplasty for unilateral ureteropelvic junction obstruction of moderate to severe hydronephrosis observed by prenatal ultrasonography to assess the appropriate timing of operation for recovery of renal function and obstruction. METHODS: We retrospectively reviewed the records of the total 28 patients who underwent pyeloplasty between 1995 and 2001 at Asan Medical Center. We compared pre and postoperative differentials in renal function and diuretic renogram as measured by technetium-99m-mercaptoacetyl- triglycerine scan and the degree of hydronephrosis by renal ultrasonography. RESULTS: In all 28 patients postoperative follow-up renal ultrasonography revealed significant improvement in hydronephrosis. In 10 poorly functioning hydronephrotic kidneys in which relative renal function function was less than 35%, renal function was improved postoperatively in 3 cases, but not improved in 7 cases. In all 28 patients postoperative follow-up diuretic renogram revealed significant improvement. CONCLUSION: We believe that the early pyeloplasty should be considered when ultrasonography and diuretic renography suggest obstruction because renal function does not improve significantly after pyeloplasty over preoperative value.

The Role of Renal Ultrasonography in Asymptomatic Microscopic Hematuria / 대한비뇨기과학회지

PURPOSE: Serious urologic lesions have been reported in 4.8% to 16.5% of patients referred for asymptomatic microscopic hematuria. This study aimed to demonstrate the cause of microscopic hematuria and to evaluate the diagnostic efficacy of urologic workup methods. MATERIALS AND METHODS: Between February 1995 and July 1999, 970 patients with asymptomatic microscopic hematuria were examined by urinalysis, urine culture, intravenous pyelography and renal ultrasonography. Patients with proterinuria of 2+ or more and RBC casts were excluded from the study. Average patient age was 53 years (20-82 years). The male-to-female ratio was approximately 1:1 (473:497). RESULTS: Among 970 patients with asymptomatic microscopic hematuria, the cause was detected in 96 patients, including 2 renal cell carcinoma and 2 bladder tumor. In patients over the age of 50 years, the incidence of malignancy was 6.6% (4/610) and higher incidence of significant lesions was found (11.0%) compared to patients under the age of 50 (8.1%). Malignancy was not found in any of the 360 patients under the age of 50 years. Neither the degree of hematuria nor sexual difference correlates with clinically significant lesions. In 96 patients with significant lesions, the detection rate of abnormalities by renal ultrasonography and IVP was 26% (25/96) and 12.5% (12/96), respectively (p=0.004). CONCLUSIONS: Our report has shown that 9.9% of the patients had significant urologic lesions including 4 malignancies. We demonstrate that renal ultrasonography was more beneficial than IVP for the evaluation of the upper tract in patients with asymptomatic microscopic hematuria. It may be more appropriate to consider renal ultrasonography in addition to IVP as an initial examination in the evaluation of microscopic hematuria.

A Comparison between Renal Ultrasonogram and Intravenous Pyelogram as a followup Study in Spinal Cord Injury Patients / 대한비뇨기과학회지

During the lest 7 years 21 children with vesicoureteral reflux and neurogenic bladder dysfunction and 46 children with primary vesicoureteral reflux were followed. At the time of initial presentation, the mean age of the former group was 5.5 years and the letter group, 2.8 years. The grade of reflux and the nephropathy were more severe in the children with neuropathic bladder than in the children with primary vesicoureteral reflux But in the same reflux grade, there was no statistical difference in the nephropathy between the two groups. The children with vesicoureteral reflux and neuropathic bladder were managed with drug therapy, intermittent catheterization, urinary diversion and ureteral reimplantation. Radiological followup revealed that resolution or improvement of reflux occurred in 36 per cent of renal units managed by intermittent catheterization and 100 per cent in which the ureters were reimplanted. As in the non-neurogenic bladder successful management of reflux and prevention of upper tract deterioration can be achieved by conservative management as well as by ureteroneocystostomy.