Prevalence of vesicoureteral reflux in neonatal urinary tract infection

Increased prevalence of non-E. coli bacteria-caused urinary infection in neonates delivered by cesarian section

OBJECTIVES

to assess the association between delivery mode and causative pathogens of infants with urinary tract infections.

MATERIALS AND METHODS

We conducted a retrospective analysis of the medical records of neonates delivered in a tertiary academic pediatric hospital and diagnosed with urinary tract infections between January 1,2013 and December 31,2017. Excluded were newborns with urinary tract infections post-urological procedures or neurogenic bladders. The retrieved data included demographic characteristics, clinical presentations, laboratory findings, urine cultures, and renal imaging results. Multivariable logistic regressions were employed to identify associations.

RESULTS

95 of the 131 neonates' (72.5%) cultures were positive for Escherichia coli. Neonates born via cesarean section (C/S) had a significantly higher prevalence (12/25, 48%) of non-Escherichia coli infections (p = 0.01). The mode of delivery was the only variable associated with non-Escherichia coli infections (odds ratio = 3.1, p = 0.014). Two of the 12 neonates (17%) with non-Escherichia coli cultures in the C/S group were diagnosed as having dilating vesicoureteral reflux.

DISCUSSION

While the impact of mode of delivery on microbiome composition and UTI risk in the pediatric population is well documented, to the best of our knowledge, our study is the first to evaluate and report on the clinical connection between mode of delivery and neonatal UTIs. Most noteworthy was our finding of an elevated prevalence of non-E. coli cultures in the C/S group (p = 0.014, OR 3.1). This bears important clinical implications, particularly in the setting of congenital anomaly of kidney and urinary tract (CAKUT) screening.

CONCLUSIONS

Our analyses in this study reveal a significant link between delivery by cesarean section and neonatal urinary tract infections with non- Escherichia coli urine cultures. These findings carry implications for vesicoureteral reflux screening in neonates by raising the level of awareness of the association between the 2 factors. Additional prospective studies on larger cohorts are warranted to further elucidate this relationship and refine clinical decision-making in neonatal care.

A retrospective study of uropathogen and its antibiotic resistance among children with urinary tract infection from a single center in China

Urinary tract infection (UTI) is a well-known bacterial infection posing serious health problem in children. A retrospective study was conducted to explore the uropathogen and its antibiotic resistance in children with UTI. Data of urine culture and antimicrobial susceptibility test was collected. Consequently, 840 children were included. The overall culture-positive UTI was 458 (54.52 %) with Escherichia coli 166 (36.24 %), followed by Enterococcus faecalis 59 (12.88 %), Enterococcus faecium 70 (15.28 %) and others. They were highly resistant to the most commonly used antibiotics. In 694 children with complicated UTI, there were 8 children with fungal infection. Multiple drug resistance (MDR) was recorded in 315 (80.98 %). The overall proportion of Extended Spectrum β-Lactamase (ESβL) production was 25 (6.43 %). In 146 children with simple UTI, MDR were also detected in 47 (77.05 %). There were 6 (9.84 %) positive for ESβL production. Our study found that complicated UTI was relatively common. Escherichia coli was the most prevalent isolate, followed by Enterococcus faecium and Enterococcus faecalis. These organisms were highly resistant to the most commonly used antibiotics. Relatively high prevalence of MDR and low ESβL-producing organisms were observed.

Imaging of Vesicoureteral Reflux: AJR Expert Panel Narrative Review

Vesicoureteral reflux (VUR) is a common congenital anomaly of the urinary tract that can present with collecting system dilation or as a febrile infection. VUR can lead to permanent renal sequelae requiring surgery but can also spontaneously resolve without complication. Therefore, recognizing patient populations who warrant imaging for screening, confirmation, or ongoing surveillance for VUR is important, as is avoiding overdiagnosis. In the appropriate patient populations, an accurate diagnosis of VUR allows early treatment and prevention of pyelonephritis and scarring. Various imaging modalities are available to diagnose and grade VUR, including voiding cystourethrography, radionucleotide cystography, and contrast-enhanced voiding urosonography (ceVUS). The objective of this article is to summarize the current understanding of VUR diagnosis and management and to discuss these imaging modalities' strengths and pitfalls. Considerations include indications for VUR imaging, patient preparation, conduct of the examination, issues related to radiologic reporting, and cost-effectiveness. An emphasis is placed on ceVUS, which is the most recently introduced of the three imaging modalities and is receiving growing support among pediatric radiologists.

Preoperative and Intraoperative Urine Cultures and Its Association With Postoperative Infection After Ureteroneocystostomy

OBJECTIVE

To unveil this association, we hypothesize that preoperative and intraoperative urinary tract infection (UTI) will be correlated with postoperative UTI and sepsis occurrence.

PATIENTS AND METHODS

The 2020 National Surgical Quality Improvement Program Pediatric (NSQIP-P) data was analyzed for patients undergoing ureteroneocystostomy (UNC) for vesicoureteral reflux (VUR). Patients that underwent UNC for treatment of VUR with urine culture obtained within 2weeks preoperatively or on the day of surgery were identified. The patients were divided into 3 groups: no bacterial growth, bacterial growth with UTI, and bacterial growth polymicrobial growth. Patient demographics and preoperative variables were evaluated.

RESULTS

The postoperative urinary tract infection rate of the three groups were 2.0%, 9.2%, and 9.9% for group A, B, C, respectively (P < .001). Postoperative sepsis was noted to be 0.5%, 1.3%, and 3.6% for group A, B, C (P < .01). Additionally, there was a difference between mean operative time (P < .001), mean length of stay (P = .03), and mean days from operation to discharge (P < .01). On adjusted analysis, both groups B and C had higher rates of UTI compared to group A. Group C was also seen to have greater rates of sepsis on adjusted analysis.

CONCLUSION

The association found between preoperative UTI with less than 2 species of microorganisms (group B) and postoperative UTI indicates that UTI treatment and antibiotic prophylaxis should be considered when undergoing UNC for VUR. The results of this study may lead to more careful consideration of the use of preoperative and intraoperative urine culture as well as treatment of UTI in pediatric patients with VUR undergoing UNC.

Prevalence, Pathogenic Bacterial Profile and Antimicrobial Susceptibility Pattern of Urinary Tract Infection Among Children with Congenital Anomalies of the Kidney and Urinary Tract

Purpose

The study was to detect the pathogenic bacterial profile and antibiogram among children with congenital anomalies of the kidney and urinary tract (CAKUT).

Patients and Methods

A retrospective analysis was performed using medical records of urine culture results and antibiotic susceptibility results in patients with UTIs from March 2017 to March 2022. Antimicrobial susceptibility pattern was determined by a standard agar disc diffusion method.

Results

A total of 568 children were included. The proportion of culture-positive UTI was 59.15% (336/568). More than nine types of bacteria were isolated with most pathogens being Gram-negative species. Among Gram-negative isolates, the predominant bacteria were Escherichia coli (30.95%, 104/336) followed by Klebsiella pneumoniae (9.23%). Escherichia coli isolates were highly sensitive to amikacin (95.19%), ertapenem (94.23%), nitrofurantoin (93.27%), imipenem (91.35%), and piperacillin-tazobactam (90.38%) and high rate of resistant were also detected to ampicillin (92.31%), cephazolin (73.08%), ceftriaxone (70.19%), trimethoprim-sulfamethoxazole (61.54%) and ampicillin-sulbactam (57.69%). Klebsiella pneumoniae isolates showed sensitive to ertapenem (96.77%), amikacin (96.77%), imipenem (93.55%), piperacillin-tazobactam (90.32%) and gentamicin (83.87%), while highly resistant were observed to ampicillin (96.77%), cephazolin (74.19%), ceftazidime (61.29%), ceftriaxone (61.29%), and aztreonam (61.29%). The isolated Gram-positive bacteria mainly contained Enterococcus faecalis and Enterococcus faecium (each 15.77%). Enterococcus faecalis were sensitive to vancomycin, penicillin-G, tigecycline, nitrofurantoin and linezolid (100%, 94.34%, 88.68%, 88.68%, 86.79, respectively) and resistant to tetracycline (86.79%), quinupristi (83.02%), erythromycin (73.58%). Enterococcus faecium also showed a similar result. Multiple drug resistance (MDR) was observed in 264 (80.00%) of the 360 bacterial isolates. Only age was significantly associated with a culture-positive UTI.

Conclusion

A higher prevalence of culture-positive UTI was detected. Escherichia coli was the most prevalent uropathogen followed by Enterococcus faecalis and Enterococcus faecium. These uropathogens showed highly resistant to the commonly used antibiotics. Moreover, MDR was commonly observed. Thus, empiric therapy is unsatisfactory as drug sensitivity always varies over time.

Prevalence and Clinical Significance of Urinary Tract Infection among Neonates Presenting with Unexplained Hyperbilirubinemia in Lebanon: A Retrospective Study

BACKGROUND

Neonatal jaundice is commonly seen in term and preterm newly born babies. It could be either physiologic or secondary to multiple underlying pathologies like urinary tract infection (UTI). Our main objective was to confirm the relationship between neonatal jaundice without apparent cause like hemolysis and the presence of UTI.

MATERIALS AND METHODS

We, retrospectively over a period extended from 2017 to 2020, included 496 babies admitted for elevated indirect hyperbilirubinemia for whom demographic, clinical, laboratory, and therapeutic data were collected through a detailed questionnaire.

RESULTS

Our study included 496 neonates and showed a prevalence of UTI in 8.9% of neonates. The two most common microorganisms in urine culture were Escherichia coli (65.9%) and Klebsiella pneumoniae (25.0%). A multivariate logistic analysis showed that UTI was associated with male neonates (odds ratio [OR] = 2.366, 95% confidence interval [CI]: 1.173 - 4.774; P = 0.016), history of prenatal UTI (OR = 5.378, 95% CI: 2.369 - 12.209; P <0.001), poor feeding (OR = 3.687, 95% CI: 1.570 - 8.661; P = 0.003), and positive urine culture in catheter (OR = 2.704, 95% CI: 1.255 - 5.826; P = 0.011). The mean length of stay was higher in patients with positive UTI (Median = 216 hours) compared to patients with negative UTI (Median = 48 hours) (P <0.001).

CONCLUSION

Neonatal sreening for UTI should be recommended whenever there is unexplaind early or prolonged hyperbilirubinemia with no evidence of alloimmune hemolysis or blood group incompatibility and to prevent the morbidity of urosepsis and congenital kidneys malformations.

Imaging Practices and Implications in Young Infants With Urinary Tract Infection

OBJECTIVES

Management of infants aged ≤60 days with urinary tract infections (UTI) is challenging. We examined renal imaging in infants aged ≤60 days with UTI at a tertiary care children's hospital to identify the impact of standardizing renal ultrasound (RUS) interpretation.

METHODS

We retrospectively studied infants aged ≤60 days hospitalized for UTI or fever with urine culture and renal imaging obtained and final diagnosis of UTI. RUS initially had noncriterion-based (NCB) interpretation by experienced pediatric radiologists. For this study, a single pediatric radiologist used a criterion-based (CB) hydronephrosis grading system to reinterpret films initially classified as "abnormal" on the NCB reading. We compared final renal imaging results between NCB and CB groups.

RESULTS

Of 193 infants, 180 (93%) had inpatient RUS with 114 (63%) abnormal NCB interpretation. Of those with initially abnormal NCB interpretation, 85 OF 114 (75%) had minor and 29 OF 114 (25%) had significant abnormality by CB reinterpretation. In follow-up, the CB "minor abnormality" group showed 25% abnormal renal imaging, whereas the "significant abnormality" group showed 77% abnormal renal imaging with 54% having high-grade reflux on a voiding cystourethrogram (VCUG). Patients with CB inpatient RUS minor abnormality showed 3% abnormal RUS at follow-up, but 13% showed high-grade reflux on VCUG.

CONCLUSIONS

Standardized RUS interpretation in young infants with UTI improved the accuracy of identification of abnormalities on follow-up renal imaging. In patients with CB minor abnormality on inpatient RUS, our results suggest limited utility of follow-up RUS; however, follow-up VCUG remained useful to identify high-grade reflux.

Comparison of Urinary Tract Dilatation and Society of Fetal Urology systems in the detection of vesicourethral reflux and renal scar

Purpose

The presence and degree of hydronephrosis is very important in the management of many diseases of the urinary tract. In this study, we aim to compare the sensitivity and specificity of 2 classification systems that are used for hydro-nephrosis grading in ultrasound, for reflux and scar detection. The classification systems were the Society of Fetal Urology (SFU) and Urinary Tract Dilatation (UTD).

Material and methods

Ultrasounds and dimercaptosuccinic acid scintigraphies (DMSA) of all patients who underwent voiding cystourethrogram (VCUG) due to urinary tract infection were examined retrospectively. DMSA was accepted for scar detection and VCUG for reflux detection as reference methods. SFU classification was used for hydronephrosis in ultrasound reports, and UTD classification was made over the reports. Sensitivity, specificity, and positive and negative predictive values of UTD and SFU classification systems for reflux and scar detection were calculated, and these 2 systems were compared.

Results

103 (39%) of the patients were male and 162 (61%) were female. Pathologies were detected in 192 (35%) of 530 kidneys in ultrasound. In 110 (42%) of the children, reflux was detected in VCUG. Scars in DMSA were detected in only 16% (44) of 266 kidneys. Sensitivity, positive and negative predictive values of the UTD classification system were statistically significantly higher than the SFU system for scar and reflux detection (p < 0.01).

Conclusions

If we use the UTD system in ultrasounds of patients with urinary tract infections, children reported as UTD 0 may not need VCUG, which reduces radiation exposure to children and the cost of the diagnostic interventions.

Radiation exposure to infants undergoing voiding cystourethrography: The importance of the digital imaging technology

PURPOSE

To determine the radiation burden to infants undergoing voiding cystourethrography (VCUG) in a single institution and investigate the effect of shifting from analogue to digital imaging that allowed the use of a radiography-free examination protocol.

METHODS

Anthropometric and exposure data were prospectively collected for 35 consecutive infants undergoing VCUG on a digital system with a standardized examination protocol not including radiographs. Thermoluminescent dosimeters were used to determine entrance-skin dose. Monte Carlo simulations and patient-specific anthropomorphic phantoms were employed to determine organ/tissue doses and effective dose (ED). The associated theoretical risk of radiation-induced cancer was determined and compared to the nominal risk of cancer induction. The radiation burden from VCUG on a modern digital system with a contemporary examination protocol was compared to corresponding data reported previously for an analogue system in the same institution.

RESULTS

The median ED from VCUG was found 47 μSv. The associated total life attributable risk of radiation-induced cancer was found 10x10^-6 and 13x10^-6 for boys and girls, respectively. VCUG was found to increase the nominal risk of cancer by a factor of 1.000025 in boys and 1.000034 in girls. Shifting from analogue to digital imaging system resulted in 89% reduction of the radiation burden from VCUG.

CONCLUSION

The theoretical radiation risks for infants undergoing VCUG using a modern digital imaging system and a radiography-free protocol were found to be minor. The transition from analogue to digital equipment resulted in considerable reduction of the radiation burden from VCUG.

Incidence of urinary tract infection in neonates with significant indirect Hyperbilirubinemia of unknown etiology: case-control study

BACKGROUND

Indirect hyperbilirubinemia is frequently encountered during neonatal period. Although it has different causes, in some cases it can't be explained. Previous studies have illustrated that jaundice could be a major sign of urinary tract infection (UTI) in neonates.

AIM OF THE WORK

We aimed to determine the association between UTI and significant unexplained neonatal indirect hyperbilirubinemia.

METHODS

This prospective controlled study was performed on 150 neonates divided in two groups (100 as cases and 50 as controls) to investigate the incidence of UTI in neonates with significant unexplained hyperbilirubinemia. Urine sample was obtained using urine catheterization technique from neonates and full urine analysis was done and cases with pyuria had urine culture to confirm UTI. Immediate renal ultrasonography (USG) was performed for neonates with UTI.

RESULTS

UTI incidence was 11% in cases while none of neonates in control group had UTI with statistical significance between cases and controls (P value < 0.05). The most common (36.4%) pathogen was Escherichia coli. Posterior urethral valve with mild hydronephrosis was diagnosed in 18.2% of UTI positive patients by renal ultrasonography.

CONCLUSION

In neonates with unexplained indirect hyperbilirubinemia, UTI should be considered as a pathological cause.

Infection control and other stewardship strategies in late onset sepsis, necrotizing enterocolitis, and localized infection in the neonatal intensive care unit

Suspected or proven late onset sepsis, necrotizing enterocolitis, urinary tract infections, and ventilator associated pneumonia occurring after the first postnatal days contribute significantly to the total antibiotic exposures in neonatal intensive care units. The variability in definitions and diagnostic criteria in these conditions lead to unnecessary antibiotic use. The length of treatment and choice of antimicrobial agents for presumed and proven episodes also vary among centers due to a lack of supportive evidence and guidelines. Implementation of robust antibiotic stewardship programs can encourage compliance with appropriate dosages and narrow-spectrum regimens.

First UTI episode in life in infants <1 year of age: Epidemiologic, clinical, microbiologic and disease recurrence characteristics

BACKGROUND

To examine the epidemiologic and microbiologic characteristics of first and recurrent UTI in young infants.

METHODS

A retrospective study of all infants <1 year hospitalized during 2014-2017 with their first UTI and followed during their first year of life.

RESULTS

191 infants were enrolled; 69 (36.12%) patients were <2 months and 32 (16.8%) developed R-UTI during the follow-up. The five most common uropathogens were Escherichia coli, Klebsiella spp., Enterococcus spp., Proteus mirabilis and Staphylococcus aureus. High resistance rates were recorded for ampicillin, amoxicillin/clavulanic acid, TMP/SMX, cefuroxime, ceftriaxone, piperacillin/tazobactam and gentamicin among E. coli and Klebsiella spp.; 29.15% E. coli and 42.9% Klebsiella spp. were ESBL-positive. 53.2% of recurrent UTI (R-UTI) episodes were diagnosed within 2 months after the initial UTI episode. E. coli (40.6%) and Klebsiella spp. (37.55) were the most frequent R-UTI pathogens. Twenty-five (78.1%) R-UTIs were caused by recurrent uropathogens representing new infections. Antibiotic resistance rates at recurrence were similar to those at initial UTI, except for a significant increase in E. coli and Klebsiella spp. resistance to piperacillin/tazobactam.

CONCLUSION

We reported high antibiotic resistance rates to major antibiotic classes used in UTI treatment. Most R-UTI episodes were caused by uropathogens different than those isolated at the initial UTI episode and were caused by highly-resistant organisms. Our findings require frequent monitoring and possible modification of the empiric and prophylactic antibiotic therapy protocols in use. As a result of our findings, the protocol for initial empiric treatment of infants with suspicion of UTI was modified by changing gentamicin to amikacin in the treatment of infants <2 months of life and amikacin monotherapy (intravenous or intramuscular) was introduced as first-line therapy for infants >2 months of life.

Urinary Tract Anomalies in Patients With Anorectal Malformations: The Role of Screening and Clinical Follow-Up

OBJECTIVE

To evaluate the efficacy of the screening protocol and the clinical follow-up to detect urological anomalies (UA) in patients with ARM (ARM-P) in our institution. Secondary aim was to define the prevalence of UA and their relationship with severity of ARM.

METHODS

ARM-P were selected from a prospectively maintained database from 2000 to 2016. Exclusion criteria were: incomplete or with less than 3 years of follow-up and absence of surgical correction of the anorectal anomalies. Data from urological screening and follow-up were collected. Patients were divided into complex malformations (Group 1) and less complex malformations (Group 2).

RESULTS

One hundred seventeen of 149 were included in the study period (62 group 1, 55 group 2). UA were detected in 36/117 at birth (30.7%) with a difference between groups (P = .0005). VUR was detected in 16 (6 with hydronephrosis, 10 with normal ultrasound at birth). A bladder ultrasound after potty training showed 18 lower urinary tract dysfunction (LUTD; 15 with UA detected at birth, 3 with normal ultrasound). 8 LUTD were found during clinical follow-up, confirmed by ultrasound. Spinal MRI detected spinal cord anomalies (SCA) in 52/117 (44.4%). Considering the subgroups with neurogenic bladder and SCA there was a difference between groups (13/33 vs 1/19).

CONCLUSION

This study suggests that ARM-P are at increased risk of UA, most of which were detected on neonatal ultrasound. While screening protocol can show 88% of UA, follow-up can detect 12.9 % of total abnormalities without difference between groups. This data has to be considered when planning follow-up for these patients.

Timing of voiding cystourethrography after febrile urinary tract infection in children: a systematic review

BACKGROUND

Despite a trend towards early voiding cystourethrography (VCUG) after febrile urinary tract infection (fUTI) in children, clinical guidelines do not comment on the optimal timing and current practice varies considerably.

OBJECTIVE

To assess whether the detection rate of vesicoureteric reflux (VUR) in children depends on the time period of VCUG procedure after onset of antibiotic therapy.

METHODS

MEDLINE, EMBASE and Cochrane Controlled Trials Register electronic databases were searched for eligible studies without language or time restriction (19 November 2018). Inclusion criteria were (1) patients <18 years of age; (2) VCUG performed in patients with fUTI after onset of antibiotic therapy either in the same patient population or in two or more different patient populations within one study at different time periods; and (3) with reported detection rate of VUR. The systematic review was carried out following the recommendations of the Cochrane Collaboration and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS

Of 4175 records, nine studies were included (number of patients, n=1745) for the main outcome prevalence of VUR by VCUG <8 days compared with VCUG ≥8 days after onset of antibiotic therapy. Pooled overall prevalence of VUR was not significantly different between the early and the late VCUG groups (risk ratio 0.98, 95% CI 0.81 to 1.19). Prevalence of VUR stratified by grade was not significantly different between the two groups.

CONCLUSION

Early VCUG within 8 days after onset of antibiotic therapy does not affect the prevalence of VUR.

TRIAL REGISTRATION NUMBER

CRD42018117545.

Urinary tract infection in pediatrics: an overview

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.

Diagnosis and Management of UTI in Febrile Infants Age 0-2 Months: Applicability of the AAP Guideline

Urinary tract infections (UTIs) are the most common bacterial infection in young infants. The American Academy of Pediatrics' (AAP) clinical practice guideline for UTIs focuses on febrile children age 2-24 months, with no guideline for infants <2 months of age, an age group commonly encountered by pediatric hospitalists. In this review, we assess the applicability of the AAP UTI Guideline's action statements for previously healthy, febrile infants <2 months of age. We also discuss additional considerations in this age group, including concurrent bacteremia and routine testing for meningitis.

The prevalence of vesicoureteral reflux in infants with first urinary tract infection following circumcision is similar to infants with UTI not following circumcision

PURPOSE

Urinary tract infections (UTIs) are common serious bacterial infections in early infancy. Ritual circumcision in neonates may increase the risk of UTI within 2 weeks of the procedure. The aims of this study were to assess the prevalence and risk factors for vesicoureteral reflux (VUR) among young infants with first UTI following circumcision, and compare it with the prevalence of VUR among young infants with first UTI not related to circumcision.

METHODS

In this retrospective cohort study, the medical records of all children aged 0-100 days who were diagnosed with UTI at Shaare Zedek Medical Center between 2005 and 2012 were reviewed for demographic, clinical and laboratory data and for the presence of VUR in voiding cystourethrography (VCUG).

RESULTS

Four hundred and sixty eight cases of UTI were included. Infants with post-circumcision UTI in our study were more likely to have associated bacteremia and abnormal renal function tests. VCUG was done for 166 infants (35%). There was no statistically significant difference in the prevalence of abnormal VCUG between infants with UTI following circumcision, in comparison to infants with UTI not following circumcision (30% vs. 36%, p = NS).

CONCLUSIONS

The decision regarding the need for radiographic evaluation and prophylactic antibiotic treatment following UTI should be made regardless if infection was related to circumcision.

Predictors of grade 3-5 vesicoureteral reflux in infants ≤ 2 months of age with pyelonephritis

BACKGROUND

This study aimed to assess predictors for grade 3-5 vesicoureteral reflux (VUR) in infants ≤ 2 months of age admitted for first urinary tract infection (UTI).

METHODS

Retrospective cohort study of 195 infants ≤ 2 months admitted to a pediatric ward for first UTI between 2006 and 2017. Clinical, laboratory, and imaging data were collected from electronic medical charts. We examined associations between grade 3-5 VUR and different patient characteristics.

RESULTS

Twenty infants (10%) were diagnosed with grade 3-5 VUR; all had fever. Infants with grade 3-5 VUR had higher blood neutrophil percentage (BNP) (65% vs. 46%, P < 0.001), higher neutrophil-to-lymphocyte ratio (NLR) (2.6 vs. 1.3, P < 0.001), more renal ultrasound abnormalities (prenatal 26% vs. 5%, P = 0.007; postnatal 84% vs. 55%, P = 0.015), and Pseudomonas UTI (15% vs. 1%, respectively, P < 0.001). NLR > 1.65 showed sensitivity 100% and specificity 61% for detecting grade 3-5 VUR. BNP > 53% showed sensitivity 100% and specificity 60% for detecting grade 3-5 VUR. BNP was the best single marker for grade 3-5 VUR with area under the curve (AUC) of 0.82 (95% CI 0.75-0.89). In a multivariate model, AUC for combination of BNP and hydronephrosis was 0.86 (95% CI 0.79-0.93, P = 0.007).

CONCLUSIONS

Infants ≤ 2 months of age admitted for a first UTI are at risk for grade 3-5 VUR and thus should undergo a voiding cystourethrography (VCUG) if their renal ultrasound is abnormal or if they have Pseudomonas UTI. Avoiding VCUG can be considered in afebrile infants and in infants with BNP < 53% or NLR < 1.65.

Robot-assisted laparoscopic ureteral reimplantation in children: a valuable alternative to open surgery

INTRODUCTION

Robot-assisted laparoscopic surgical systems have led to new minimally invasive options for complex reconstructive procedures in children including for vesicoureteral reflux (VUR). Robot-assisted laparoscopic ureteral reimplantation has been shown to be a viable minimally invasive surgical option for children with VUR. However, higher-than-expected complication rates and sub-optimal reflux resolution rates at some centers have also been reported.

METHODS

This article provides a focused literature review as well as current perspectives on open reimplantation and robot-assisted laparoscopic ureteral reimplantation as non-endoscopic surgical options for pediatric VUR.

RESULTS

The heterogeneity of surgical outcomes may, in part, be due to the learning curve inherent with all new technology and procedures. As a result, the current gold standard surgical option for VUR continues to be open ureteral reimplantation. While it remains to be seen if robot-assisted laparoscopic surgery will gradually replace open surgery as the most utilized surgical option for VUR in pediatric patients, robot-assisted laparoscopic ureteral reimplantation with the current robotic surgical systems may be just one step toward an eventual minimally invasive option that all experienced surgeons can offer with the requisite high success rates and low major complication rates.

CONCLUSION

Robot-assisted laparoscopic ureteral reimplantation remains a viable minimally invasive surgical option for children with VUR, but with the expected learning curve associated with all new technologies.

Incidence and risk factors of urinary tract infection in very low birth weight infants

OBJECTIVES

To describe the incidence and associated risk factors of urinary tract infection (UTI) in very low birth weight (VLBW) infants and to determine the value of diagnostic imaging studies after the first UTI episode before discharge from the neonatal intensive care unit (NICU).

METHODS

VLBW infants born during 2003-2012 were reviewed for UTI. In a nested case-control study, potential risk factors of UTI were compared between infants with UTI (cases) versus birth weight and gestational age matched controls. Renal ultrasonography (USG) and voiding cystourethrography (VCUG) results were reviewed in cases.

RESULTS

During the study period, 54.7% of urine culture specimens were collected by sterile methods. 3% (45/1,495) of VLBW infants met the study definition for UTI. UTI was diagnosed at mean postnatal age of 33.1±22.9 days. There was no significant difference in gender, ethnicity, antenatal steroid exposure, blood culture positive sepsis, ionotropic support, respiratory support and enteral feeding practices between cases and controls. Cases had a significantly higher cholestasis compared to controls (22% vs. 9% ; p = 0.03). However, cholestasis was not a significant predictor of UTI in the adjusted analysis [adjusted OR 2.38 (95% CI 0.84 to 6.80), p = 0.11]. Cases had higher central line days, parenteral nutrition days, total mechanical ventilation days, chronic lung disease, and length of stay compared to controls. Renal USG was abnormal in 37% and VCUG was abnormal in 17% of cases.

CONCLUSIONS

The incidence of UTI in contemporary VLBW infants is relatively low compared to previous decades. Since no significant UTI predictors could be identified, urine culture by sterile methods is the only reliable way to exclude UTI. The majority of infants with UTI have normal renal anatomy. UTI in VLBW infants is associated with increased morbidity and length of stay.

[Urinary tract infection caused by Enterobacteriaceae and its relationship with vesicoureteral reflux]

BACKGROUND

The first urinary tract infection can be a marker of a urinary tract anomaly, mainly vesicoureteral reflux. The aim of this work was to determine the association between isolated enterobacteria with the presence and grade of vesicoureteral reflux in neonatal patients with their first urinary tract infection.

METHODS

A retrospective, observational and analytic study of newborns, who were admitted to the Neonatal Department, University Pediatric Hospital "Juan Manuel Márquez," in Havana, Cuba, from 1992 to 2013 was conducted. The causal microorganism of urinary tract infection was from the Enterobacteriaceae family. They were evaluated by radio imaging. The association between the presence and grade of vesicoureteral reflux with the causal microorganism of the urinary tract infection was analyzed.

RESULTS

Newborn infants with urinary tract infection (450) were studied. Bacterial isolations in the urine cultures corresponded to E. coli in 316 cases (70.2%). The prevalence of vesicoureteral reflux was 18.2%. The presence of bacteria corresponding to the Enterobacteriaceae family (other than E. coli) had significant risk association with vesicoureteral reflux (OR: 2.02; p < 0.01) and vesicoureteral reflux classification (for higher grades, p < 0.01).

CONCLUSIONS

E. coli is the most frequent causal microorganism in neonatal urinary tract infection. However, an association between the isolation of a microorganism of the Enterobacteriaceae family different to E. coli with the presence of vesicoureteral reflux and mainly with higher grades of vesicoureteral reflux exists.

Paediatric Urinary Tract Infection: A Hospital Based Experience

INTRODUCTION

Paediatric Urinary Tract Infection (UTI) is one of the commonly encountered entities by paediatricians. Studies have shown easy vulnerability of paediatric urinary tract in any acute febrile illness and a miss in diagnosis could have long term consequences like renal scaring with its adverse effects. Bearing these evidence based preludes in view we designed our study to know the prevalence of UTI in Kashmir province.

AIM

Aim of the present study was to know the prevalence of UTI in febrile children and to know the sensitivity of different imaging modalities like Renal and Urinary Bladder Ultrasonography (RUS), Voiding Cystourethrography (VCUG) and Dimercaptosuccinic Acid (DMSA) scan in diagnosing UTI.

MATERIALS AND METHODS

A total of 304 patients, between 2 months to 10 years, with axillary temperature of ≥ 100.4^oF (38^oC), who did not have a definite source for their fever and who were not on antibiotics were included in the study. Detailed history and through clinical examination was done to rule out any potential or definite focus of infection as per the predesigned proforma. Routine urine examination with culture and sensitivity, followed by RUS and VCUG was done in all patients where routine urine examination was suggestive of UTI. DMSA was done in only culture proven cases after 6 months to document the renal scarring.

RESULTS

Out of 304 children, 140 were males and 164 were females, UTI was present in 40 patients who had fever without any apparent cause giving a prevalence of 13.2%. Escherichia coli (E. coli) were the commonest isolated organism, followed by Klebsiella and Citrobacter species. Renal and Urinary Bladder Ultrasonography (RUS) detected Vesicoureteral Reflux (VUR) in 25% (10/40) while VCUG showed VUR in 55% (22/40) giving a RUS sensitivity of 45% for detecting VUR. DMSA done only after 6 months in UTI diagnosed patients showed a renal scarring in 25% (10/40) patients.

CONCLUSION

Missing a febrile paediatric UTI, can prove a future catastrophe if not timely diagnosed and treated.

Surgical management of vesicoureteral reflux with recurrent urinary tract infection after renal transplantation in a dog

CASE DESCRIPTION A 3-year-old male Cocker Spaniel renal transplant recipient was readmitted 39 weeks after transplantation because of acute clinical signs of pollakiuria, intermittent vomiting, decreased appetite, lethargy, and mild fever. CLINICAL FINDINGS Hydronephrosis and hydroureter were observed with ultrasonography and contrast cystography, and a diagnosis of vesicoureteral reflux (VUR) was made. Urinary tract infection (UTI) caused by Escherichia coli was also diagnosed on the basis of results of urine culture. TREATMENT AND OUTCOME Despite treatment of the UTI with an appropriate antimicrobial for 6 weeks, the VUR persisted and the UTI recurred 9 weeks after cessation of antimicrobial treatment. Therefore, surgical correction by means of revision extravesicular ureteroneocytostomy was performed. Both VUR and hydronephrosis resolved after surgery. No recurrences of clinical signs of urinary tract complications were observed during the subsequent 22-month follow-up period. CLINICAL RELEVANCE Results suggested that ureteral reimplantation with an extravesicular technique incorporating a long submucosal tunnel may be an effective treatment for VUR when medical management fails in canine renal transplant recipients with recurrent UTIs.

Urinary Imaging Findings in Young Infants With Bacteremic Urinary Tract Infection

OBJECTIVES

To describe renal ultrasound (RUS) and voiding cystourethrogram (VCUG) findings and determine predictors of abnormal imaging in young infants with bacteremic urinary tract infection (UTI).

METHODS

We used retrospective data from a multicenter sample of infants younger than 3 months with bacteremic UTI, defined as the same pathogenic organism in blood and urine. Infants were excluded if they had any major comorbidities, known urologic abnormalities at time of presentation, required intensive unit care, or had no imaging performed. Imaging results as stated in the radiology reports were categorized by a pediatric urologist.

RESULTS

Of the 276 infants, 19 were excluded. Of the remaining 257 infants, 254 underwent a RUS and 224 underwent a VCUG. Fifty-five percent had ≥1 RUS abnormalities. Thirty-four percent had ≥1 VCUG abnormalities, including vesicoureteral reflux (VUR, 27%), duplication (1.3%), and infravesicular abnormality (0.9%). Age <1 month, male sex, and non-Escherichia coli organism predicted an abnormal RUS, but only non-E coli organism predicted an abnormal VCUG. Seventeen of 96 infants (17.7%) with a normal RUS had an abnormal VCUG: 15 with VUR (Grade I-III = 13, Grade IV = 2), 2 with elevated postvoid residual, and 1 with infravesical abnormality.

CONCLUSIONS

Although RUS and VCUG abnormalities were common in this cohort, the frequency and severity were similar to previous studies of infants with UTIs in general. Our findings do not support special consideration of bacteremia in imaging decisions for otherwise well-appearing young infants with UTI.

Dimercaptosuccinic acid scan or ultrasound in screening for vesicoureteral reflux among children with urinary tract infections

BACKGROUND

There is considerable interest in detecting vesicoureteral reflux (VUR) because its presence, especially when severe, has been linked to an increased risk of urinary tract infections and renal scarring. Voiding cystourethrography (VCUG), also known as micturating cystourethrography, is the gold standard for the diagnosis of VUR, and the grading of its severity. Because VCUG requires bladder catheterisation and exposes children to radiation, there has been a growing interest in other screening strategies that could identify at-risk children without the risks and discomfort associated with VCUG.

OBJECTIVES

The objective of this review is to evaluate the accuracy of two alternative imaging tests - the dimercaptosuccinic acid renal scan (DMSA) and renal-bladder ultrasound (RBUS) - in diagnosing VUR and high-grade VUR (Grade III-V VUR).

SEARCH METHODS

We searched MEDLINE, EMBASE, BIOSIS, and the Cochrane Register of Diagnostic Test Accuracy Studies from 1985 to 31 March 2016. The reference lists of relevant review articles were searched to identify additional studies not found through the electronic search.

SELECTION CRITERIA

We considered published cross-sectional or cohort studies that compared the results of the index tests (DMSA scan or RBUS) with the results of radiographic VCUG in children less than 19 years of age with a culture-confirmed urinary tract infection.

DATA COLLECTION AND ANALYSIS

Two authors independently applied the selection criteria to all citations and independently abstracted data. We used the bivariate model to calculate summary sensitivity and specificity values.

MAIN RESULTS

A total of 42 studies met our inclusion criteria. Twenty studies reported data on the test performance of RBUS in detecting VUR; the summary sensitivity and specificity estimates were 0.44 (95% CI 0.34 to 0.54) and 0.78 (95% CI 0.68 to 0.86), respectively. A total of 11 studies reported data on the test performance of RBUS in detecting high-grade VUR; the summary sensitivity and specificity estimates were 0.59 (95% CI 0.45 to 0.72) and 0.79 (95% CI 0.65 to 0.87), respectively. A total of 19 studies reported data on the test performance of DMSA in detecting VUR; the summary sensitivity and specificity estimates were 0.75 (95% CI 0.67 to 0.81) and 0.48 (95% CI 0.38 to 0.57), respectively. A total of 10 studies reported data on the accuracy of DMSA in detecting high-grade VUR. The summary sensitivity and specificity estimates were 0.93 (95% CI 0.77 to 0.98) and 0.44 (95% CI 0.33 to 0.56), respectively.

AUTHORS' CONCLUSIONS

Neither the renal ultrasound nor the DMSA scan is accurate enough to detect VUR (of all grades). Although a child with a negative DMSA test has an < 1% probability of having high-grade VUR, performing a screening DMSA will result in a large number of children falsely labelled as being at risk for high-grade VUR. Accordingly, the usefulness of the DMSA as a screening test for high-grade VUR should be questioned.

Renal Ultrasound for Infants Younger Than 2 Months With a Febrile Urinary Tract Infection

OBJECTIVE

The purpose of this study is to determine the performance of renal ultrasound for detecting vesicoureteral reflux (VUR) and obstructive uropathies in infants younger than 2 months with a febrile urinary tract infection (UTI).

MATERIALS AND METHODS

We performed a retrospective cohort study of infants younger than 2 months with fever and culture-proven UTI presenting from July 1, 2008, through December 31, 2011, with renal ultrasound and voiding cystourethrogram (VCUG) performed within 30 days of UTI diagnosis. Two pediatric radiologists independently reviewed the renal ultrasound and VCUG findings. Results of the renal ultrasound were deemed abnormal if collecting system dilation, renal size asymmetry, collecting system duplication, urothelial thickening, ureteral dilation, or bladder anomalies were present. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of renal ultrasound were calculated using VCUG as reference standard.

RESULTS

Of the 197 patients included (mean [SD] age, 33 [ 15 ] days; male-to-female ratio, 2:1), 25% (n = 49) had VUR grades I-V, with 16% (n = 31) having VUR grades III-V and 8% (n = 15) having VUR grades IV-V. For grades I-V VUR, sensitivity was 32.7% (95% CI, 20.0-47.5%), specificity was 69.6% (95% CI, 61.5-76.9%), PPV was 26.2% (95% CI, 15.8-39.1%), and NPV was 75.7% (95% CI, 67.6-82.7%). For grades III-V VUR, sensitivity was 51.6% (95% CI, 33.1-69.9%), specificity was 72.9% (95% CI, 65.5-79.5%), PPV was 26.2% (95% CI, 15.8-39.1%), and NPV was 89.0% (95% CI, 82.5-93.7%). For grades IV-V VUR, sensitivity was 86.7% (95% CI, 59.5-98.3%), specificity was 73.6% (95% CI, 66.6-79.9%), PPV was 21.3% (95% CI, 11.9-33.7%), and NPV was 98.5% (95% CI, 94.8-99.8%). No obstructive uropathies were diagnosed by VCUG in patients with normal renal ultrasound findings.

CONCLUSION

In infants younger than 2 months, a normal renal ultrasound makes the presence of grades IV and V VUR highly unlikely but does not rule out lower grades of VUR.

Significance of Sonographically Demonstrated Ureteral Dilatation in Evaluation of Vesicoureteral Reflux Verified with Voiding Urosonography in Children with Urinary Tract Infection

Objectives:

The aim of this study was to determine sensitivity, specificity, and predictive values of sonographically demonstrated ureteral dilatation in detecting vesicoureteral reflux (VUR).

Methods:

Ethical approval from the Ethical Committee of Clinical Center University of Sarajevo and parental consent were obtained for this prospective study involving 120 children with history of urinary tract infections (UTIs). Ultrasound examination included the evaluation of the urinary tract, with a special emphasis on evaluation of ureteral dilatation. Voiding urosonography (VUS) was carried out according to a standard protocol with the use of ultrasound contrast agent Sono Vue of second generation. Ureteral diameter greater than 3 mm was considered pathological. Proven VUR was graded into one of three stages.

Results:

Infectio tracti urinarii recidivans was referral diagnosis in the majority of patients. The average age of patients was 4.33 ± 3.88 years (from 2 months to 16 years of age). VUS findings were normal in 59 (49.2%), and pathological in 61 (50.8%) patients. Statistical analysis showed significant correlation between type and grade of VUR. Our data confirmed predominance of VUR in females and in children under the age of 5. Statistically significant correlation between ureteral dilatation and the existence of VUR was found, with relatively high sensitivity (67.2%), specificity (81.4%), and high positive (78.8%) and negative predictive value (70.6%), total diagnostic accuracy of 74.2% in detecting VUR, and significantly increased probability (20 – 25%) of detecting VUR in patients with sonographically confirmed ureteral dilatation.

Conclusion:

Sonographically confirmed ureteral dilatation can be used as a predictor of VUR in children with UTIs, and in combination with other predictors, might find a place in an evidence-based selective strategy in children with suspected VUR.

Intravoxel incoherent motion magnetic resonance imaging to predict vesicoureteral reflux in children with urinary tract infection

OBJECTIVES

To compare the diffusion parameters of intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) between the "reflux" and the "non-reflux" kidneys, and to evaluate the feasibility of using IVIM DWI to predict vesicoureteral reflux (VUR) in children with a urinary tract infection (UTI).

METHODS

Eighty-three kidneys from 57 pediatric patients with a UTI were classified into "reflux" and "non-reflux" groups according to voiding cystourethrography (VCUG) results. The apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (PF) were measured and compared in the renal pelvis of both groups. Four indices (D*/ADC, PF/ADC, D*/D, and PF/D) were calculated and receiver operating characteristic (ROC) curve analyses were performed.

RESULTS

VURs were detected on VCUG in 21 kidneys. PF and D* were significantly higher in the "reflux" group than in the "non-reflux" group. The indices were all significantly higher. The PF/D index showed the best diagnostic performance in predicting VUR in children with UTI (Az = 0.864).

CONCLUSION

PF and D* were significantly higher in the "reflux" kidney than in the "non-reflux" kidney. Our new index (PF/D) could prove useful for predicting VUR.

KEY POINTS

• IVIM DWI is both radiation-free and contrast media-free. • IVIM DWI index is easily calculated by combining diffusion parameters. • IVIM DWI may help predict VUR in children with UTI. • PF is significantly higher in the "reflux" than the "non-reflux" kidneys. • A new VUR index, PF/D could prove useful for predicting VUR.

Urinary tract infections in the infant

Urinary tract infection (UTI) in an infant may be the first indication of an underlying renal disorder. Early recognition and initiation of adequate therapy for UTI is important to reduce the risk of long-term renal scarring. Ampicillin and gentamicin are traditionally the empiric treatment of choice; however, local antibiotic resistance patterns should be considered. Maternal antibiotics during pregnancy also increase the risk of resistant pathogens during neonatal UTI. Long-term management after the first UTI in infants remains controversial because of lack of specific studies in this age group and the risk-benefit issues for antibiotic prophylaxis between reduced recurrent disease and emergent antibiotic resistance.

Meaning of ureter dilatation during ultrasonography in infants for evaluating vesicoureteral reflux

PURPOSE

To investigate the meaning of ureter dilatation during ultrasonography (US) in infants for evaluating vesicoureteral reflux (VUR).

MATERIALS AND METHODS

We retrospectively reviewed abdominal US images of infants who were diagnosed with urinary tract infection (UTI group) or only hydronephrosis without UTI (control group). Hydronephrosis (graded 0-4) and ureter dilatation (present or absent) were evaluated on each side with US. Voiding cystourethrography (VCUG) within 3 months time interval with US was also reviewed and VUR was graded (0-5) on each side. Hydronephrosis, ureter dilatation, and VUR were then compared between the two groups.

RESULTS

Four hundred and three infants (142 in the UTI group and 261 in the control group) were included and VCUG was performed in 129 infants (68 in UTI and 61 in control groups). VUR grades were not different between the two groups (p=0.252). Hydronephrosis grade was not related to VUR in either group (p>0.05). However, ureter dilatation had a significant relationship with VUR in the UTI group (p=0.015), even among patients with a high-grade VUR (p=0.005). Whereas, ureter dilatation was not associated with VUR in the control group (p=0.744). The relationship between ureter dilatation and VUR was different between the two groups for both all grades (p=0.014) and high-grade (p=0.004) VUR. Ureter dilatation had 66.7% sensitivity, 80.3% specificity, and 79.4% accuracy for evaluating high-grade VUR in the UTI group.

CONCLUSION

Ureter dilatation on US can be a helpful finding for detecting VUR in infants with UTI, but not infants without UTI.

Practical approach to screen vesicoureteral reflux after a first urinary tract infection

Introduction:

Vesicoureteral reflux (VUR) is a common pediatric urologic disorder. After the first urinary tract infection (UTI), imaging studies are recommended, starting with a renal ultrasound (RUS). Voiding cystourethrography (VCUG) and dimercaptosuccinic acid (DMSA) scan are the other main radiologic studies used to detect VUR. We evaluated the use of RUS as a screening method for VUR in children below 2 years of age, in order to avoid unnecessary VCUG.

Materials and Methods:

Medical records and imaging studies of infants (<2 years) who had their first UTI in a 6 year period were retrospectively reviewed. We evaluated the sensitivity, specificity, and negative predictive values of RUS and DMSA for diagnosing VUR.

Results:

Among 155 children (51% males) with their first UTI, 148 RUS were performed, 128 VCUG and 29 DMSA. VUR was detected in 21% patients; 14.5% low grade and 6.5% high grade. One hundred and twenty-one patients underwent both RUS and VCUG, 101 RUS were normal and 20 abnormal. Of the normal RUS 98% had no or low grade VUR. Among those with an abnormality on RUS 30% had high grade VUR (P < 0.001).

Conclusions:

After the first UTI in infants (<2 years) RUS is a good screening method for VUR. Among such shildren with a normal RUS, we do not recommend VCUG or DMSA. In our opinion, VCUG should be performed only in patients with abnormal findings in RUS or in recurrent UTI.

Diagnosis and management of urinary tract infection and vesicoureteral reflux in the neonate

Urinary tract infection (UTI) is the most common bacterial infection in febrile newborns, particularly those born prematurely and with a low birth weight. Vesicoureteral reflux (VUR) predisposes to UTI and renal scarring. Half of neonates with UTI may have only low-grade fever or no fever. Jaundice in the absence of any other symptoms or signs may be the only clinical manifestation of UTI in neonates. The urinalysis may be negative in a significant number of neonates with UTI. Newborns with UTI have a high incidence of congenital anomalies of kidney and urinary tract anomalies, and hence should undergo renal imaging.

Are clinical, laboratory, and imaging markers suitable predictors of vesicoureteral reflux in children with their first febrile urinary tract infection?

Purpose

This study was conducted to determine the predictive value of clinical, laboratory, and imaging variables for the diagnosis of vesicoureteral reflux in children with their first febrile urinary tract infection.

Materials and Methods

One hundred fifty-three children with their first febrile urinary tract infection were divided into two groups according to the results of voiding cystourethrography: 60 children with vesicoureteral reflux and 93 children without. The sensitivity, specificity, positive and negative predictive value, likelihood ratio (positive and negative), and accuracy of the clinical, laboratory, and imaging variables for the diagnosis of vesicoureteral reflux were determined.

Results

Of the 153 children with febrile urinary tract infection, 60 patients (39.2%) had vesicoureteral reflux. There were significant differences between the two groups regarding fever>38℃, suprapubic pain, C-reactive protein quantitative level, number of red blood cells in the urine, and results of renal ultrasound and dimercaptosuccinic acid renal scanning (p<0.05). There were significant positive correlations between fever>38.2℃ and dimercaptosuccinic acid renal scanning and vesicoureteral reflux. Also, there were significant positive correlations between the erythrocyte sedimentation rate, positive urinary nitrite test, hyaline cast, and renal ultrasound and high-grade vesicoureteral reflux.

Conclusions

This study revealed fever>38.2℃ and dimercaptosuccinic acid renal scanning as the best predictive markers for vesicoureteral reflux in children with their first febrile urinary tract infection. In addition, erythrocyte sedimentation rate, positive urinary nitrite test, hyaline cast, and renal ultrasound are the best predictive markers for high-grade vesicoureteral reflux.

Voiding urosonography with second-generation ultrasound contrast versus micturating cystourethrography in the diagnosis of vesicoureteric reflux

Vesicoureteric reflux has been associated with paediatric urinary tract infection. Fluoroscopic micturating cystourethrography (MCU) has been the gold standard of diagnostic test for decades; however, it has been criticized owing to its lower detection rate and radiation dose to children. Therefore, new radiation-free reflux imaging modalities have been developed, in which ultrasound-based contrast-enhanced voiding urosonography (ceVUS) is a good example. However, ultrasonography has been considered as an operator-dependent examination. Therefore, our study aimed to examine the inter-observer agreement of this sonographic technique, which has not been evaluated before. Moreover, the second-generation ultrasound contrast SonoVue has been recently marketed, and the data on its efficacy on intravesical use in ceVUS is relatively scarce. Thus, we also aimed to investigate the diagnostic performance and safety profile of SonoVue-enhanced VUS in the diagnosis of vesicoureteric reflux. Our prospective comparative study compared the diagnostic performance of ceVUS with MCU in young children presenting with first episode of urinary tract infection. We performed sequential ceVUS and MCU examinations in 31 patients (62 pelvi-ureter units). Perfect inter-observer agreement (Cohen’s kappa statistics = 1.0, p < 0.001) was achieved in ceVUS, suggesting its good reliability in reflux detection and grading. Using MCU as reference, ceVUS had 100 % sensitivity and 84 % specificity and carried higher reflux detection rate than MCU (p < 0.001). There was no complication encountered. Conclusion: Voiding urosonography is a reliable, sensitive, safe and radiation-free modality in the investigation of vesicoureteric reflux in children. It should be incorporated in the diagnostic algorithm in paediatric urinary tract infection.

Urinary tract infection in outpatient febrile infants younger than 30 days of age: a 10-year evaluation

BACKGROUND

To determine the prevalence of outpatient-diagnosed urinary tract infection (UTI) in consecutive febrile neonates ≤ 30 days of age and correlate demographic, laboratory and radiographic imaging results with infectious etiology.

METHODS

Review of medical records of consecutive febrile infants ≤ 30 days of age presenting to an urban pediatric emergency department during a 10-year period, whose policy is to perform a sepsis evaluation (urine culture obtained by bladder catheterization) and hospitalize for parenteral antibiotic therapy pending culture results.

RESULTS

Of 670 febrile neonates ≤ 30 days of age evaluated for sepsis, urine culture was obtained in 651 cases (97%). Of 100 patients with UTI (15.4%), 73% were male; the most common uropathogens were Escherichia coli (71%), Enterococcus (10%) and Klebsiella sp. (10%). In all, 39% had a maximum documented fever ≥ 102 °F, and 40% had CBC total white blood cells count ≥ 15,000/mm(3). Urine dipstick test was positive for leukocyte esterase or nitrite in 79%. Renal ultrasound performed in 95 patients (95%) showed anatomic abnormalities in 47%; 5/26 (24%) with hydronephrosis had vesicoureteral reflux on voiding cystourethrogram. Four patients had urosepsis; none had bacterial meningitis and no patients died.

CONCLUSIONS

UTI affects approximately 1 in 6 febrile neonates ≤ 30 days of age. Males are affected 2.5-times greater than females. E. coli continues to be the predominant uropathogen. Clinical parameters like height of fever, CBC total white blood cell count and urine dipstick test lack sensitivity in identifying UTI risk in the outpatient setting. Only 4 infants had urosepsis (4%). Nearly half of neonates with UTI have a radiographically identified anatomic abnormality. All febrile young infants should receive performance of a urine culture; those with UTI require imaging.

Effect of pro-inflammatory cytokine (IFN-γ +874, IL-18-137 G/C,-607 C/A) genes in relation to risk of vesico-ureteral reflux

AIM

The aim this work is to estimate whether genetic polymorphisms of +874 of IFN-γ and -137 G/C,-607 C/A of IL-18 genes are implicated in the development of VUR, because a vast literature indicates that genetic variations play a significant role in the pathogenesis of VUR.

MATERIALS AND METHODS

The PCR single specific primer (SSP) and amplification refractory mutation system (ARMS) were applied for analyzing the polymorphic sites of -137 G/C,-607 C/A of IL-18 and +874 of IFN-γ genes in 110 healthy controls and 124 VUR children.

RESULTS

A significant relationship was found between AT and combined AT + TT genotypes of IFN-γ and highly increased risk of VUR (OR = 4.2, 95% CI, 2.00-9.24; p < 0.0001: OR = 4.00, 95% CI, 1.90-8.70, p < 0.0001, respectively). On the other hand, the genotype frequency of IL18-137 G/C indicated a significant assessment of the decrease risk of VUR for GC and GC + CC genotypes (OR = 0.53, 95% CI, 0.3-0.9; p = 0.02: OR = 0.53, 95% CI, 0.3-0.92 p = 0.01, respectively). No significant association was found between -607 C/A polymorphism of IL-18 and UVR.

CONCLUSION

To the author's best knowledge, this is the first data regarding polymorphism of IFN-γ (+874) cytokine genes that highly increased the risk of VUR. To confirm the presented data, further studies should be done in different populations with a larger sample size.

The frequency of vesicoureteral reflux diagnosis is correlated with urbanization level of residence in pediatric population: a nationwide study in Taiwan

OBJECTIVE

To investigate the frequency and characteristics of newly diagnosed vesicoureteral reflux (VUR) in children younger than 18 years based on a nationwide database in Taiwan.

METHODS

The present study utilizes a subset of the Taiwan's National Health Insurance Research Database, known as the Longitudinal Health Insurance Database 2005, which contains the data of all paid medical benefit claims over 1997-2007 for a subset of 1,000,000 beneficiaries randomly drawn from the population of 22.72 million individuals during any part of the 2005 calendar year. Our analysis includes the data of all pediatric patients with the diagnosis of VUR.

RESULTS

A total of 738 subjects with VUR diagnosis were identified, including 412 (55.8%) boys and 326 (44.2%) girls. The peak age of VUR occurrence was the first year for males and 1-4 years for females. Approximately 49.7% of all subjects presented with urinary tract infection (UTI); moreover, there were significant differences between genders concerning the presence of UTI (RR = 0.8; p = 0.002). The occurrence rate of VUR in the pediatric population ranged from 2.63 in 1998 to 3.94 in 2003 per 10,000 children during 1998-2005. The frequency of newly-diagnosed VUR in the pediatric population was significantly correlated with urbanization levels of residence.

CONCLUSION

The nationwide, population-based study of pediatric VUR shows there were gender differences in age distribution and presence of UTI. Further studies are warranted to clarify the correlations between urbanization level of residence and occurrence of VUR.

Predict the spontaneous resolution of vesicoureteral reflux by direct radionuclide cystography

OBJECTIVES

To evaluate the prognostic value of initial direct radionuclide cystography (DRC) for spontaneous resolution of vesicoureteral reflux (VUR).

METHODS

Fifty-one children with initial diagnosis and 1-6 years' follow-up of VUR by DRC were enrolled in this study. VUR was graded according to the anatomic grading as (1) mild reflux corresponding to tracer just in ureter, (2) moderate reflux with accumulation of activity in a non-dilated collecting system and ureter, and (3) severe reflux equated with a dilated ureter and collecting system. The severity of VUR was also expressed according to the functional classification as (1) transient reflux, which occurred at filling or voiding phase only and (2) persistent reflux, present in both filling and voiding phases.

RESULTS

Twenty-nine of the 51 children had unilateral VUR, and the other 22 had bilateral VUR. In the total of 73 refluxing ureters, there were 12 mild, 49 moderate and 12 severe VUR according to anatomic grading, and 30 transient and 43 persistent VUR according to the functional grading. After follow-up, resolution of VUR was found in 92% (11/12) of mild, 59% (29/49) of moderate and 25% (3/12) of severe VUR (P=.04, mild vs. moderate; P=.003, mild vs. severe). Eighty percent (24/30) of transient and 44% (19/43) of persistent reflux showed spontaneous resolution (P=.003).

CONCLUSIONS

DRC allows anatomic and functional classification of VUR. It is an ideal method for the diagnosis, staging and follow-up of VUR, and provides valuable information to predict the patient's outcome.

Interactive magnetic resonance voiding cystourethrography (iMRVC) for vesicoureteric reflux (VUR) in unsedated infants: a feasibility study

OBJECTIVES

The current reference standard for diagnosing vesicoureteric reflux is the X-ray-based Micturating CystoUrethroGram (MCUG). The aim of this study was to evaluate the feasibility of performing interactive Magnetic Resonance voiding cysto-urethrography (iMRVC) in un-sedated infants.

METHODS

Twelve infants underwent conventional single-cycle MCUG followed by iMRVC. In iMRVC, patients were examined using an in-house developed fluoroscopic pulse sequence, which allows on-the-fly control of image contrast and geometry. A single acquisition was performed during bladder filling, during and after micturition, with interactive control over imaging parameters. Images were assessed for diagnostic quality and presence of VUR.

RESULTS

Every case of reflux identified with MCUG was identified on iMRVC (100% sensitivity). Over 24 renal units, there was 88% concordance (21/24) according to the presence of reflux between the two methods. There were three "false positives" detected by MRI, giving a specificity of 83.3%, PPV of 66.7% and NPV of 100%.

CONCLUSION

iMRVC is a feasible method for evaluating the renal tract in infants without the need for radiation or sedation. A formal evaluation is required to establish its diagnostic potential.

Prevalence of renal anomalies after urinary tract infections in hospitalized infants less than 2 months of age

OBJECTIVE

Our aim was to determine the incidence of anatomical abnormalities after a urinary tract infection (UTI) in infants <2 months of age hospitalized in the neonatal intensive care unit (NICU).

STUDY DESIGN

This was a retrospective, single-center cohort study of infants <2 months of age in the NICU with a UTI and documented renal imaging.

RESULT

We identified 141 infants with UTIs. The mean gestational age and birth weight were 28 weeks and 1254 g, respectively. The most commonly identified pathogen was coagulase-negative Staphylococcus (28%, 44 of 156). A major abnormality was found on at least one imaging study for 4% (5 of 118) of infants. Major abnormalities were noted on 4% (5 of 114) of renal ultrasounds and 2% (2 of 82) of voiding cystourethrography examinations.

CONCLUSION

Among infants in the NICU <2 months of age at the time of a UTI, the prevalence of major anatomical abnormalities is <5%.

Altered expression of c-kit-positive cells in the ureterovesical junction after surgically created vesicoureteral reflux

PURPOSE

Peristaltic contractions propel urine unidirectionally from the renal pelvis trough the ureter and into the bladder. A morphologically and functionally competent ureterovesical junction prevents vesicoureteral reflux (VUR). According to current knowledge, pyeloureteral peristalsis is driven by atypical muscle cells within the upper urinary tract. Another likely relevant cell population, which is c-kit-positive, has been shown to be present within the whole urinary tract. Morphological changes of c-kit-positive cells have been described in VUR and pyeloureteral junction (PUJ) obstruction. Nevertheless, the functional importance of c-kit-positive interstitial cells has not yet been elucidated fully. Therefore, we investigated the influence of experimentally created VUR on the expression of c-kit-positive cells.

MATERIALS AND METHODS

We created left-sided unilateral VUR in eight Vietnamese pigs using an open surgical technique. The VUR was shown to be grade II-III by voiding cystourethrogram (VCUG), 1 and 6 months after the procedure. The animals were killed after 6 months. The vesicoureteral junction and the distal ureters were excised and fixed in 4% PFA. Paraffin sections were stained using c-kit immunohistochemistry. A quantitative evaluation was performed by two independent investigators. The unaffected, contralateral, nonrefluxing ureters served as controls.

RESULTS

We identified two types of c-kit-immunoreactive cells within the ureterovesical junction and distal ureter. The first group was comprised of round-shaped cells with substantial intracellular granulas, which resembled mast cells. Mast cells were found in the subepithelial region as well as between the muscle bundles. The number of mast cells was slightly increased in the VUR group. The second group consisted of spindle-shaped, bipolar ICC-like cells, which were seen mainly in the submucosal and muscular layers. The number of spindle-shaped c-kit-immunoreactive cells was markedly decreased in the refluxing ureter compared to the controls.

CONCLUSIONS

Surgically created VUR leads to altered expression of c-kit-positive cells. The altered distribution of c-kit-positive ICC-like cells might further contribute to the impairment of coordinated pyeloureteral peristalsis.

Implications of 99mTc-DMSA scintigraphy performed during urinary tract infection in neonates

OBJECTIVE

To evaluate prospectively whether normal scintigraphic results during urinary tract infections (UTIs) in neonates were predictive of the absence of dilating vesicoureteral reflux (VUR) (grade > or =III) and permanent renal damage (PRD).

METHODS

Term neonates with a first symptomatic, community-acquired UTI participated in the study. Urinary tract ultrasonography and technetium-99m-labeled dimercaptosuccinic acid ((99m)Tc-DMSA) scintigraphy were performed within 72 hours after diagnosis and voiding cystourethrography within 1 to 2 months. DMSA scintigraphy, to determine the development of PRD, was repeated 6 months after UTI.

RESULTS

Seventy-two neonates (144 renal units) were enrolled. Acute pyelonephritis was diagnosed through early DMSA scintigraphy in 19% of renal units, VUR in 22%, and grade > or =III VUR in 13%. The majority (71%) of renal units with grade > or =III VUR had normal early DMSA scintigraphic results. The sensitivity and specificity of abnormal early DMSA scintigraphic results to predict grade > or =III VUR were 29% (95% confidence interval: 11%-55%) and 82% (95% confidence interval: 74%-88%), respectively. PRD was found in 7% of renal units, all of which had abnormal early DMSA scintigraphic results. PRD was significantly more frequent among renal units with grade > or =III VUR than among nonrefluxing renal units (P < .05).

CONCLUSIONS

Normal early DMSA scintigraphic results for neonates with symptomatic UTIs were helpful in ruling out later development of PRD but were not predictive of the absence of dilating VUR. To rule out dilating VUR, voiding cystourethrography may be required.

Vesicoureteral reflux and urinary tract infection: evolving practices and current controversies in pediatric imaging

OBJECTIVE

Pediatric patients with urinary tract infection (UTI) undergo imaging tests to detect vesicoureteral reflux (VUR) in the belief that VUR correlates to risk of renal scarring. This article describes recent evolution and controversies in the management of UTI and VUR.

CONCLUSION

Multitechnique imaging of UTI and VUR is complex and controversial. Evolution in practice patterns is motivated by the desire to rationally minimize unnecessary interventions and radiation exposure. Ongoing evidence-based research is needed to further improve practice guidelines.

Vesicoureteral reflux

Vesicoureteral reflux (VUR), the retrograde flow of urine from the bladder toward the kidney, is common in young children. About 30% of children with urinary tract infections will be diagnosed with VUR after a voiding cystourethrogram. For most, VUR will resolve spontaneously; 20% to 30% will have further infections, but few will experience long-term renal sequelae. Developmentally, VUR arises from disruption of complex signaling pathways and cellular differentiation. These mechanisms are probably genetically programmed but may be influenced by environmental exposures. Phenotypic expression of VUR is variable, ranging from asymptomatic forms to severe renal parenchymal disease and end-stage disease. VUR is often familial but is genetically heterogeneous with variability in mode of inheritance and in which gene, or the number of genes, that are involved. Numerous genetic studies that explore associations with VUR are available. The relative utility of these for understanding the genetics of VUR is often limited because of small sample size, poor methodology, and a diverse spectrum of patients. Much, if not all, of the renal parenchymal damage associated with end-stage disease is likely to be congenital, which limits the opportunity for intervention to familial cases where risk prediction may be available. Management of children with VUR remains controversial because there is no strong supportive evidence that prophylactic antibiotics or surgical intervention improve outcomes. Furthermore, well-designed genetic epidemiological studies focusing on the severe end of the VUR phenotype may help define the causal pathway and identify modifiable or disease predictive factors.

Urinary tract infection in the newborn: clinical and radio imaging studies

The objective of this study was to assess clinical characteristics and results of radio imaging studies and compare community-acquired urinary tract infection (UTI) with nosocomial UTI in 301 neonates with UTI consecutively admitted to 28 neonatal units in Spain over 3 years (community-acquired UTI, n = 250; nosocomial UTI, n = 51). UTI was diagnosed in the presence of symptoms of infection together with any colony growth for a single pathogen from urine obtained by suprapubic aspiration, or >or=10(4) CFU/ml for a single pathogen from urine obtained by urethral catheterization. Abnormal renal ultrasound was present in 37.1% of cases (34% in community-acquired UTI and 54.5% in nosocomial UTI, P < 0.01). The voiding cystourethrography (VCUG) showed vesicoureteral reflux (VUR) in 27% of cases (23.8% in community-acquired UTI and 48.6% in nosocomial UTI, P < 0.01). In patients with abnormal renal ultrasound and VUR, renal scan with dimercaptosuccinic acid (DMSA) performed early after UTI revealed cortical defects in 69.5% of cases. However, in patients with abnormal renal ultrasound and normal VCUG, DMSA also revealed cortical defects in 39% of cases. The absence of VUR in neonates with UTI and abnormal renal ultrasound does not exclude the presence of cortical defects suggestive of pyelonephritis.