Imaging studies after a first febrile urinary tract infection in young children

The role of ultrasonography in predicting vesicoureteral reflux

OBJECTIVE

To evaluate the accuracy of renal and bladder ultrasonography (RBU) in predicting vesicoureteral reflux (VUR) in infants and children.

MATERIALS AND METHODS

A total of 134 children who had VUR demonstrated on voiding cystourethrography (VCU) and also had RBU within 1 month of the VCU were included in the study, which took place between January 2005 and December 2012. VUR and hydronephrosis were graded with standard methods on VCU and RBU, respectively. Using VCU findings of reflux as the gold standard, diagnostic accuracy measures were performed for hydronephrosis and ureteral visualization on RBU, including sensitivity, specificity, positive predictive value, negative predictive value, and accuracy.

RESULTS

Reflux grade was significantly associated with the degree of hydronephrosis (P = .0032). The sensitivity, negative predictive value, and accuracy of ultrasonography in predicting reflux was significantly higher for grade IV+ or grade V reflux compared with lower reflux grades. Also, the specificity of ultrasonography in predicting reflux was constant and at high level across all reflux grades, suggesting that ultrasonography is a good diagnostic screening tool.

CONCLUSION

Normal RBU is rare with grade IV-V reflux, and moderate to severe hydronephrosis is rare with reflux grades <IV. RBU is a valid screening test for the selection of patients with a first urinary tract infection who should undergo VCU. Diagnosis of grade IV and V reflux will be delayed in very few cases, using a definition of abnormal RBU to include all degrees of hydronephrosis (Society for Fetal Urology classification).

Urinary tract infections in infants and children: Diagnosis and management

Recent studies have resulted in major changes in the management of urinary tract infections (UTIs) in children. The present statement focuses on the diagnosis and management of infants and children >2 months of age with an acute UTI and no known underlying urinary tract pathology or risk factors for a neurogenic bladder. UTI should be ruled out in preverbal children with unexplained fever and in older children with symptoms suggestive of UTI (dysuria, urinary frequency, hematuria, abdominal pain, back pain or new daytime incontinence). A midstream urine sample should be collected for urinalysis and culture in toilet-trained children; others should have urine collected by catheter or by suprapubic aspirate. UTI is unlikely if the urinalysis is completely normal. A bagged urine sample may be used for urinalysis but should not be used for urine culture. Antibiotic treatment for seven to 10 days is recommended for febrile UTI. Oral antibiotics may be offered as initial treatment when the child is not seriously ill and is likely to receive and tolerate every dose. Children <2 years of age should be investigated after their first febrile UTI with a renal/bladder ultrasound to identify any significant renal abnormalities. A voiding cystourethrogram is not required for children with a first UTI unless the renal/bladder ultrasound reveals findings suggestive of vesicoureteral reflux, selected renal anomalies or obstructive uropathy.

Predictive risk factors in childhood urinary tract infection, vesicoureteral reflux, and renal scarring management

Approaches to the management of children with urinary tract infection (UTI), vesicoureteral reflux (VUR), and renal scars have been challenged and have become controversial over the past decade. It is difficult to determine when, how, and which patients will benefit from the diagnosis and management of this condition. Therefore, the issues of diagnostic imaging, observation, follow-up, and intervention tend to be decided more on a case-by-case basis, rather than by using an algorithm. Over the past few years, there have been advances in the identification of risk factors that predispose patients with UTI to present with VUR, to develop recurrent UTIs and renal scars, to have deteriorating renal function, to show VUR improvement and/or spontaneous resolution, and to be candidates for and benefit from early surgical intervention.

Efficacy of antibiotic prophylaxis in children with vesicoureteral reflux: systematic review and meta-analysis

PURPOSE

Controversy exists regarding the use of continuous antibiotic prophylaxis vs observation in the management of children with vesicoureteral reflux. The reported effectiveness of continuous antibiotic prophylaxis in children with reflux varies widely. We determined whether the aggregated evidence supports use of continuous antibiotic prophylaxis in children with vesicoureteral reflux.

MATERIALS AND METHODS

We searched the Cochrane Controlled Trials Register, clinicaltrials.gov, MEDLINE(®), EMBASE(®), Google Scholar and recently presented meeting abstracts for reports in any language. Bibliographies of included studies were then hand searched for any missed articles. The study protocol was prospectively registered at PROSPERO (No. CRD42014009639). Reports were assessed and data abstracted in duplicate, with differences resolved by consensus. Risk of bias was assessed using standardized instruments.

RESULTS

We identified 1,547 studies, of which 8 are included in the meta-analysis. Pooled results demonstrated that continuous antibiotic prophylaxis significantly reduced the risk of recurrent febrile or symptomatic urinary tract infection (pooled OR 0.63, 95% CI 0.42-0.96) but, if urinary tract infection occurred, increased the risk of antibiotic resistant organism (pooled OR 8.75, 95% CI 3.52-21.73). A decrease in new renal scarring was not associated with continuous antibiotic prophylaxis use. Adverse events were similar between the 2 groups. Significant heterogeneity existed between studies (I(2) 50%, p = 0.03), specifically between those trials with significant risk of bias (eg unclear protocol descriptions and/or lack of blinding).

CONCLUSIONS

Compared to no treatment, continuous antibiotic prophylaxis significantly reduced the risk of febrile and symptomatic urinary tract infections in children with vesicoureteral reflux, although it increased the risk of infection due to antibiotic resistant bacteria. Continuous antibiotic prophylaxis did not significantly impact the occurrence of new renal scarring or reported adverse events.

Comparison of procalcitonin and different guidelines for first febrile urinary tract infection in children by imaging

BACKGROUND

We examined the ability of a procalcitonin (PCT) protocol to detect vesicoureteral reflux (VUR) and renal scarring (RS), evaluated procedural costs and radiation burden, and compared four representative guidelines for children with their first febrile urinary tract infection (UTI).

METHODS

Children aged ≤2 years with their first febrile UTI who underwent renal ultrasonography (US), acute and late technetium-99m ((99m)Tc)-dimercaptosuccinic acid scan, and voiding cystourethrography were prospectively studied. The representative guidelines applied in a retrospective simulation included the American Academy of Pediatrics (AAP), National Institute of Clinical Excellence, top-down approach (TDA), and Italian Society of Pediatric Nephrology (ISPN). These were compared in terms of ability to detect abnormalities, procedural costs and radiation.

RESULTS

Of 278 children analyzed, 172 (61.9%) had acute pyelonephritis. There was VUR in 101 (36.3%) children, including 73 (26.3%) with grades III-V VUR. RS was identified in 75 (27.0%) children. To detect VUR, TDA and PCT had the highest sensitivity for grades I-V VUR (80.2%) and III-V VUR (94.5%), respectively, whereas AAP had the highest specificity for I-V VUR (77.4%) and III-V VUR (78.0%), respectively. TDA and PCT had the highest sensitivity (100%) for detecting RS. The highest cost and radiation dose was associated with TDA, whereas AAP had the least expenditure and radiation exposure. By multivariate analysis, PCT and VUR, especially grades III-V, were independent predictors of RS.

CONCLUSIONS

There is no perfect guideline for first febrile UTI children. The PCT protocol has good ability for detecting high-grade VUR and RS. If based on available imaging modalities and reducing cost and radiation burden, clinical suggestions in the AAP guidelines represent a considerable protocol.

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.

Antimicrobial prophylaxis for children with vesicoureteral reflux

BACKGROUND

Children with febrile urinary tract infection commonly have vesicoureteral reflux. Because trial results have been limited and inconsistent, the use of antimicrobial prophylaxis to prevent recurrences in children with reflux remains controversial.

METHODS

In this 2-year, multisite, randomized, placebo-controlled trial involving 607 children with vesicoureteral reflux that was diagnosed after a first or second febrile or symptomatic urinary tract infection, we evaluated the efficacy of trimethoprim-sulfamethoxazole prophylaxis in preventing recurrences (primary outcome). Secondary outcomes were renal scarring, treatment failure (a composite of recurrences and scarring), and antimicrobial resistance.

RESULTS

Recurrent urinary tract infection developed in 39 of 302 children who received prophylaxis as compared with 72 of 305 children who received placebo (relative risk, 0.55; 95% confidence interval [CI], 0.38 to 0.78). Prophylaxis reduced the risk of recurrences by 50% (hazard ratio, 0.50; 95% CI, 0.34 to 0.74) and was particularly effective in children whose index infection was febrile (hazard ratio, 0.41; 95% CI, 0.26 to 0.64) and in those with baseline bladder and bowel dysfunction (hazard ratio, 0.21; 95% CI, 0.08 to 0.58). The occurrence of renal scarring did not differ significantly between the prophylaxis and placebo groups (11.9% and 10.2%, respectively). Among 87 children with a first recurrence caused by Escherichia coli, the proportion of isolates that were resistant to trimethoprim-sulfamethoxazole was 63% in the prophylaxis group and 19% in the placebo group.

CONCLUSIONS

Among children with vesicoureteral reflux after urinary tract infection, antimicrobial prophylaxis was associated with a substantially reduced risk of recurrence but not of renal scarring. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; RIVUR ClinicalTrials.gov number, NCT00405704.).

Clinical and microbiological characteristics of Klebsiella pneumoniae from community-acquired recurrent urinary tract infections

Understanding the pathogenesis of recurrent urinary tract infection (RUTI) and whether it is attributable to reinfection with a new strain or relapse with the primary infecting strain is of considerable importance. Because previous studies regarding community-acquired Klebsiella pneumoniae RUTI are inconclusive, we undertook this study to evaluate the characteristics of the host and the bacterial agent K. pneumoniae in RUTI. A prospective study was designed, using consecutive patients diagnosed with community-acquired K. pneumoniae-related UTI from January 2007 to December 2009. Of the total 468 consecutive episodes, we found 7 patients with RUTI. All the patients with RUTI were elderly (median, 74 years), with diabetes (100 %, 7 out of 7). Clinical K. pneumoniae isolates derived from the same patients with RUTI revealed identical genomic fingerprints, indicating that K. pneumoniae UTI relapsed despite appropriate antibiotic therapy. The antimicrobial resistance, growth curve and biofilm formation of the recurrent isolates did not change. K. pneumoniae strains causing RUTI had more adhesion and invasiveness than the colonization strains (p < 0.01). When we compared the recurrent strains with the community-acquired UTI strains, the prevalence of diabetes mellitus was significant (100 % vs 53.7 %, p = 0.03) in the RUTI group. Our data suggest that K. pneumoniae strains might be able to persist within the urinary tract despite appropriate antibiotic treatment, and the greater adhesion and invasiveness in the recurrent strains may play an important role in recurrent infections.

Renal cortical abnormalities in siblings of index patients with vesicoureteral reflux

OBJECTIVE

Screening siblings of index patients with vesicoureteral reflux (VUR) has been proposed to identify children who are at risk for renal damage. However, screening siblings for VUR remains controversial. We investigated the prevalence of VUR and renal cortical abnormalities in the sibling population in a large cohort of families with VUR.

METHODS

Between 1998 and 2012, parents of index patients with grade III to V VUR were asked permission to screen siblings <6 years of age for VUR. Siblings were divided into 2 groups: siblings with a documented history of a previous urinary tract infection (UTI) and siblings who were screened for VUR and never had a UTI. A logistic regression model was used to determine independent risk factors associated with renal cortical abnormalities such as history of presentation, age, gender, and grade of VUR.

RESULTS

There were 318 siblings in 275 families in the study. VUR was found after screening in 190 (60%) siblings and after a UTI in 128 (40%). Multivariate analysis revealed that siblings who had a previous UTI (odds ratio: 3.38), siblings with high grade reflux (odds ratio: 3.62), and siblings over 1 year of age (odds ratio: 2.84) were the most significant independent risk factors associated with renal cortical abnormalities.

CONCLUSIONS

There is increased risk of renal cortical abnormalities in siblings with a previous UTI, siblings with high-grade VUR, and siblings over age 1 year. This information may help to counsel parents about the risk of VUR and reflux nephropathy in familial VUR.

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.

Ultrasound as a screening test for genitourinary anomalies in children with UTI

BACKGROUND

The 2011 American Academy of Pediatrics guidelines state that renal and bladder ultrasound (RBUS) should be performed after initial febrile urinary tract infection (UTI) in a young child, with voiding cystourethrogram (VCUG) performed only if RBUS shows abnormalities. We sought to determine test characteristics and predictive values of RBUS for VCUG findings in this setting.

METHODS

We analyzed 3995 clinical encounters from January 1, 2006 to December 31, 2010 during which VCUG and RBUS were performed for history of UTI. Patients who had previous postnatal genitourinary imaging or history of prenatal hydronephrosis were excluded. Sensitivity, specificity, and predictive values of RBUS for VCUG abnormalities were determined.

RESULTS

We identified 2259 patients age <60 months who had UTI as the indication for imaging. RBUS was reported as "normal" in 75%. On VCUG, any vesicoureteral reflux (VUR) was identified in 41.7%, VUR grade >II in 20.9%, and VUR grade >III in 2.8%. Sensitivity of RBUS for any abnormal findings on VCUG ranged from 5% (specificity: 97%) to 28% (specificity: 77%). Sensitivity for VUR grade >III ranged from 18% (specificity: 97%) to 55% (specificity: 77%). Among the 1203 children aged 2 to 24 months imaged after a first febrile UTI, positive predictive value of RBUS was 37% to 47% for VUR grade >II (13% to 24% for VUR grade >III); negative predictive value was 72% to 74% for VUR grade >II (95% to 96% for VUR grade >III).

CONCLUSIONS

RBUS is a poor screening test for genitourinary abnormalities. RBUS and VCUG should be considered complementary as they provide important, but different, information.

Sibship size, sibling cognitive sensitivity, and children's receptive vocabulary

OBJECTIVES

The aim of the current study was to examine the relationship between sibship size and children's vocabulary as a function of quality of sibling interactions. It was hypothesized that coming from a larger sibship (ie, 3+ children) would be related to lower receptive vocabulary in children. However, we expected this association to be moderated by the level of cognitive sensitivity shown by children's next-in-age older siblings.

METHODS

Data on 385 children (mean age = 3.15 years) and their next-in-age older siblings (mean age = 5.57 years) were collected and included demographic questionnaires, direct testing of children's receptive vocabulary, and videos of mother-child and sibling interactions. Sibling dyads were taped engaging in a cooperative building task and tapes were coded for the amount of cognitive sensitivity the older sibling exhibited toward the younger sibling.

RESULTS

Hierarchical regression analyses were conducted and showed an interaction between sibship size and sibling cognitive sensitivity in the prediction of children's receptive vocabulary; children exposed to large sibships whose next-in-age older sibling exhibited higher levels of cognitive sensitivity were less likely to show low vocabulary skills when compared with those children exposed to large sibships whose siblings showed lower levels of cognitive sensitivity.

CONCLUSIONS

Children who show sensitivity to the cognitive needs of their younger siblings provide a rich environment for language development. The negative impact of large sibships on language development is moderated by the presence of an older sibling who shows high cognitive sensitivity.

Prevalence and risk factors for renal scars in children with febrile UTI and/or VUR: a cross-sectional observational study of 565 consecutive patients

PURPOSE

To determine prevalence and risk factors for renal scar in children referred for urologic assessment of febrile UTI and/or VUR.

METHODS

Pre-determined risk factors for renal scar were prospectively recorded in consecutive patients referred for UTI/VUR. Age, gender, VUR grade, and reported number of febrile and non-febrile UTIs were analyzed with logistic regression to determine risk for focal cortical defects on non-acute DMSA.

RESULTS

Of 565 consecutive children, 24 (4%) had congenital renal dysplasia and 84 (15.5%) had focal defect(s). VUR, especially grades IV-V, recurrent febrile UTI, and older age increased risk. For any age child with the same number of UTIs, VUR increased odds of renal defect 5.4-fold (OR = 5.4, 95% CI = 2.7-10.6, AUC = 0.759).

CONCLUSIONS

Focal DMSA defects were present in 15.5% of 565 consecutive children referred for febrile UTI and/or VUR; 4% had presumed congenital reflux nephropathy without cortical defect. All VUR grades increased risk for these defects, as did recurrent febrile UTIs and older age. However, 43% with grades IV-V VUR and 76% with recurrent UTI had normal DMSA.

Current medical diagnosis and management of vesicoureteral reflux in children

Vesico-ureteral reflux (VUR) is presented in approximately %1 of children and is associated with an increased risk of pyelonephritis and renal scarring. Despite its prevalence and morbidity, many aspects of VUR diagnosis and treatment are controversial. We objectively assessed the published data; the data base for many current diagnoses and treatment patterns of VUR is limited. Recent studies have focused on developed determination of VUR-related renal morbidity, improved stratification tools that children would benefit most from which VUR treatment option, and improved reporting of the long-term outcomes of VUR treatments in children who are at risk for VUR. In this review, the advances in the diagnosis and treatment of VUR will be accompanied by the current guidelines.

Using intravoxel incoherent motion MR imaging to evaluate cortical defects in the first episode of upper urinary tract infections: preliminary results

PURPOSE

To compare intravoxel incoherent motion diffusion weight imaging IVIM-DWI MRI with DMSA for the evaluation of cortical defect in pediatric upper urinary tract infection (UTI) patients.

MATERIALS AND METHODS

Forty-three kidneys of 22 pediatric patients with the first episode of febrile upper UTI were evaluated. DWI using IVIM model was performed with eight b factors. The presence of cortical defect was evaluated on apparent diffusion coefficient (ADC) map. DMSA was used as the standard of reference. ADC, true diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (F) in both defect and nondefect area were calculated and compared.

RESULTS

Cortical defects were detected in 14 kidneys by IVIM-DWI. The sensitivity, specificity, positive predictive value, and negative predictive value of IVIM-DWI MRI for the detection of defects was 93.3%, 100%, 100%, and 96.5%, respectively. Mean values of ADC, D, D*, and F were 1.12 ± 0.15, 1.05 ± 0.10, 33 ± 17 (× 10(-3) mm(2) /s), and 0.14 ± 0.09 in the defect foci. In normal foci, ADC, D, D*, and F were 1.37 ± 0.09, 1.31 ± 0.10, 43 ± 19 (× 10(-3) mm(2) /s), and 0.12 ± 0.04, respectively. ADC and D were significantly lower in defect group than nondefect group (P < 0.01).

CONCLUSION

IVIM-DWI can allow both direct visualization and quantitative measurement of cortical defects.

Role of procalcitonin in predicting dilating vesicoureteral reflux in young children hospitalized with a first febrile urinary tract infection

OBJECTIVE

The aim of this article was to assess the usefulness of procalcitonin (PCT) as a marker for predicting dilating (grades III-V) vesicoureteral reflux (VUR) in young children with a first febrile urinary tract infection.

METHODS

Children ≤2 years of age with a first febrile urinary tract infection were prospectively evaluated. Serum samples were tested for PCT at the time of admission to a tertiary hospital. All children underwent renal ultrasonography (US), Tc-dimercaptosuccinic acid renal scan, and voiding cystourethrography. The diagnostic characteristics of PCT test for acute pyelonephritis and dilating VUR were calculated.

RESULTS

Of 272 children analyzed (168 boys and 104 girls; median age, 5 months), 169 (62.1%) had acute pyelonephritis. There was VUR demonstrated in 97 (35.7%), including 70 (25.7%) with dilating VUR. The median PCT value was significantly higher in children with VUR than in those without (P < 0.001). Using a PCT cutoff value of ≥1.0 ng/mL, the sensitivity and negative predictive value for predicting dilating VUR were 94.3% and 95.4%, respectively, for PCT, and 97.1% and 97.8%, respectively, for the combined PCT and US studies, whereas the positive and negative likelihood ratios were 2.03 and 0.107, respectively, for PCT, and 1.72 and 0.067, respectively, for the combined studies. By multivariate analysis, high PCT values and abnormalities on US were independent predictors of dilating VUR.

CONCLUSIONS

PCT is useful for diagnosing acute pyelonephritis and predicting dilating VUR in young children with a first febrile urinary tract infection. A voiding cystourethrography is indicated only in children with high PCT values (≥1.0 ng/mL) and/or abnormalities found on a US.

Does routine ultrasound change management in the follow-up of patients with vesicoureteral reflux?

INTRODUCTION

Children with vesicoureteral reflux (VUR) usually need a renal ultrasound (RUS). There is little data on the role of follow-up RUS in VUR. We evaluated the impact of follow-up RUS on the change in clinical management in patients with VUR.

METHODS

We prospectively analyzed children with a previous diagnosis of VUR seen in the outpatient clinic with a routine follow-up RUS within 4 months. Variables collected included: demographic data, VUR history, dysfunctional voiding symptoms and concurrent ultrasound findings. Change in management was defined as addition of new medication, nurse counselling, surgery or further investigations.

RESULTS

The study included 114 consecutive patients. The mean patient age was 4.5 years old, mean age of VUR diagnosis was 1.7 years, with average follow-up of 2.8 years. A change in management with stable RUS occurred in 14 patients, in which the change included ordering a DMSA in 9, nurse counselling for dysfunctional voiding in 3, and booking surgery in 2 patients. Change on RUS was seen in 4 patients. Multivariable analysis showed that history of urinary tract infection (UTI) since the last follow-up visit was more significant than RUS findings.

CONCLUSIONS

The RUS findings in most patients followed for VUR remain stable or with minimal changes. The variable showing a significant effect on change in management in our study was history of UTI since the last follow-up visit rather than RUS findings. The value of follow-up RUS for children with VUR may need to be revisited.

The RIVUR trial: profile and baseline clinical associations of children with vesicoureteral reflux

BACKGROUND AND OBJECTIVE

Vesicoureteral reflux (VUR) is diagnosed in ∼30% to 40% of children who have imaging studies after urinary tract infections (UTIs). Our goal is to characterize children enrolled in the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) trial and to compare our study cohort with those from previously published studies.

METHODS

RIVUR investigators from 19 pediatric sites in the United States recruited 607 children with grade I through IV VUR. Children were enrolled after a first or second UTI. This cross-sectional report of baseline data includes extensive clinical, parental report, and imaging study results.

RESULTS

RIVUR recruited 607 children (558 girls, 49 boys) with grade I (11%), II (42%), III (38%), or IV (8%) reflux. The median age was 12 months, and most children (91%) were enrolled after their first UTI. The UTI leading to enrollment was both febrile and symptomatic for 323 children, febrile only in 197 children, and symptomatic only in 86. Renal involvement at baseline as documented by a (99m)Tc dimercaptosuccinic acid scan was uncommon with cortical defects identified in 89 (15%) children. Bladder and bowel dysfunction was identified in 71 (56%) of 126 toilet-trained subjects assessed.

CONCLUSIONS

RIVUR is the largest prospective, randomized trial for children with primary VUR to date, comparing prophylaxis with placebo. The study sample comprises patients from 19 pediatric clinical sites in the United States, whose demographic and clinical characteristics may differ from those of children enrolled in previous trials from other countries.

History of recurrent urinary tract infection is not predictive of abnormality on voiding cystourethrogram

PURPOSE

The American Academy of Pediatrics recently recommended against routine voiding cystourethrograms (VCUGs) in children 2 to 24 months with initial febrile UTI, raising concern for delayed diagnosis and increased risk of UTI-related renal damage from vesicoureteral reflux (VUR). We assessed factors potentially associated with higher likelihood of abnormal VCUG, including UTI recurrence, which could allow for more judicious test utilization.

METHODS

We retrospectively reviewed all initial VCUGs performed at Children's Hospital of Michigan between January and June, 2010. History of recurrent UTI was ascertained by evidence of two or more prior positive cultures or history of "recurrent UTI" on VCUG requisition. Outcomes assessed included rates of VUR or any urologic abnormality on VCUG.

RESULTS

Two hundred and sixty-two patients met inclusion criteria. VUR was detected in 21.3 %, urologic abnormality including VUR in 27.4 %. Degree of bladder distension, department of referring physician, study indication, positive documented urine culture, and history of recurrent UTI or UTI and other abnormality were all not associated with increased likelihood of VUR or any urologic abnormality on VCUG.

CONCLUSION

VUR and VCUG abnormality are no more likely when performed after recurrent UTI or for UTI plus other abnormality. This reasons against postponing VCUG until after UTI recurrence, as positive findings are no more likely in this setting.

Different imaging strategies in febrile urinary tract infection in childhood. What, when, why?

Urinary tract infections (UTIs) are a common problem in childhood. During the last decade, published papers led to a deep revision in the use and usefulness of imaging tools in children with febrile UTIs. This new body of knowledge was partially endorsed by the guidelines published in 2007 by the UK's National Institute for Clinical Excellence and in 2011 by the American Academy of Pediatrics. Nevertheless, new data continuously arise and the scientific debate always revives. Recommendations of published guidelines and strengths and weaknesses of the available biochemical and imaging tools are here critically analysed for giving to the reader a complete, up-to-date and flexible overview on this hot topic.

Different guidelines for imaging after first UTI in febrile infants: yield, cost, and radiation

OBJECTIVE

To evaluate the yield, economic, and radiation costs of 5 diagnostic algorithms compared with a protocol where all tests are performed (ultrasonography scan, cystography, and late technetium(99)dimercaptosuccinic acid scan) in children after the first febrile urinary tract infections.

METHODS

A total of 304 children, 2 to 36 months of age, who completed the diagnostic follow-up (ultrasonography, cystourethrography, and acute and late technetium(99)dimercaptosuccinic acid scans) of a randomized controlled trial (Italian Renal Infection Study 1) were eligible. The guidelines applied to this cohort in a retrospective simulation were: Melbourne Royal Children's Hospital, National Institute of Clinical Excellence (NICE), top down approach, American Academy of Pediatrics (AAP), and Italian Society of Pediatric Nephrology. Primary outcomes were the yield of abnormal tests for each diagnostic protocol; secondary outcomes were the economic and radiation costs.

RESULTS

Vesicoureteral reflux (VUR) was identified in 66 (22%) children and a parenchymal scarring was identified in 45 (15%). For detection of VUR (47/66) and scarring (45/45), the top down approach showed the highest sensitivity (76% and 100%, respectively) but also the highest economic and radiation costs (€52 268. 624 mSv). NICE (19/66) and AAP (18/66) had the highest specificities for VUR (90%) and the Italian Society of Pediatric Nephrology had the highest specificity (20/45) for scars (86%). NICE would have been the least costly (€26 838) and AAP would have resulted in the least radiation exposure (42 mSv).

CONCLUSIONS

There is no ideal diagnostic protocol following a first febrile urinary tract infection. An aggressive protocol has a high sensitivity for detecting VUR and scarring but carries high financial and radiation costs with questionable benefit.

Prevalence and predictors of renal functional abnormalities of high grade vesicoureteral reflux

PURPOSE

The association of vesicoureteral reflux, febrile urinary tract infections and renal parenchymal damage is well recognized. We determined the prevalence and predictors of renal functional abnormalities in children with high grade vesicoureteral reflux.

MATERIALS AND METHODS

We retrospectively reviewed the medical records and dimercapto-succinic acid scans of 774 consecutive children with primary high grade vesicoureteral reflux (grade IV-V) seen at our institution between 1998 and 2011. For multivariate analysis we analyzed variables associated with renal functional abnormalities, such as presentation history, age, gender and reflux grade, in a logistic regression model.

RESULTS

Of the children 698 (90%) and 76 (10%) had grade IV and V reflux, respectively. Dimercapto-succinic acid scans revealed renal functional abnormalities in 291 children (37.6%), including 240 (34%) with grade IV and 51 (67%) with grade V reflux. Univariate analysis showed that age greater than 1 year (OR 2.95, p <0.001), grade V reflux (OR 4.09, p <0.001) and preoperative bladder/bowel dysfunction (OR 2.94, p = 0.026) were significant predictors of renal functional abnormalities. Multivariate analysis showed that age greater than 1 year (OR 3.45, p = 0.001) and grade V reflux (OR 5.89, p <0.001) were the most significant independent predictors of such abnormalities.

CONCLUSIONS

There is an increased risk of renal functional abnormalities in children older than 1 year and those with grade V vesicoureteral reflux. Patients with a history of bladder/bowel dysfunction are also at greater risk for such abnormalities. The early detection and treatment of high grade vesicoureteral reflux may prevent acquired renal parenchymal damage and limit the progression of renal damage in patients with congenital reflux nephropathy.

Primary vesico-ureteric reflux: The need for individualised risk stratification

The management of paediatric primary vesico-ureteric reflux (VUR) has undergone serial changes over the last decade. As this disorder is extremely heterogeneous, and high-quality prospective data are limited, the treatment strategies vary among centres. Current treatment options include observation only, continuous antibiotic prophylaxis, and surgery. Surgical intervention is indicated if a child has a breakthrough urinary tract infection (UTI) while on continuous antibiotic prophylaxis or if there are renal scars present. After excluding a secondary cause of VUR the physician should consider the risk factors affecting the severity of VUR and manage the child accordingly. Those factors include demographic factors (age at presentation, gender, ethnicity) and clinical factors (VUR grade, unilateral vs. bilateral, presence of renal scars, initial presentation, the number of UTIs, and presence of any voiding or bowel dysfunction). In this review we summarise the major controversial issues in current reports on VUR and highlight the importance of individualised patient management according to their risk stratification.

Pediatric urinary tract infection: does the evidence support aggressively pursuing the diagnosis?

The epidemiology of pediatric fever has changed considerably during the past 2 decades with the development of vaccines against the most common bacterial pathogens causing bacteremia and meningitis. The decreasing incidence of these 2 conditions among vaccinated children has led to an emphasis on urinary tract infection as a remaining source of potentially hidden infections in febrile children. Emerging literature, however, has led to questions about both the degree and nature of the danger posed by urinary tract infection in nonverbal children, whereas the aggressive pursuit of the diagnosis consumes resources and leads to patient discomfort, medical risks, and potential overdiagnosis. We review both early and emerging literature to examine the utility and efficacy of early identification and treatment of urinary tract infection in children younger than 24 months. We conclude that in well children of this age, it may be reasonable to withhold or delay testing for urinary tract infection if signs of other sources are apparent or if the fever has been present for fewer than 4 to 5 days.

Urinary macrophage migration inhibitory factor serves as a potential biomarker for acute kidney injury in patients with acute pyelonephritis

Conventional markers of kidney function that are familiar to clinicians, including the serum creatinine and blood urea nitrogen levels, are unable to reveal genuine injury to the kidney, and their use may delay treatment. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine, and the predictive role and pathogenic mechanism of MIF deregulation during kidney infections involving acute kidney injury (AKI) are not currently known. In this study, we showed that elevated urinary MIF levels accompanied the development of AKI during kidney infection in patients with acute pyelonephritis (APN). In addition to the MIF level, the urinary levels of interleukin (IL)-1β and kidney injury molecule (KIM)-1 were also upregulated and were positively correlated with the levels of urinary MIF. An elevated urinary MIF level, along with elevated IL-1β and KIM-1 levels, is speculated to be a potential biomarker for the presence of AKI in APN patients.

The role of DMSA renal scintigraphy in the first episode of urinary tract infection in childhood

OBJECTIVE

The role of dimercaptosuccinic acid (DMSA) renal scintigraphy in the first episode of urinary tract infection (UTI) has been the subject of debate for many years. The aim of this study was to evaluate the relationship of voiding cystourethrography (VCUG), renal ultrasonography and DMSA renal scintigraphy and to detect renal parenchymal changes by performing DMSA renal scintigraphy at 6 months after the first episode of UTI.

METHODS

A prospective study was conducted in 67 hospitalized children (46 boys, 21 girls). Mean age of the patients was 0.97 ± 1.57 years (0.02-7.26 years). All children received VCUG, renal ultrasonography and DMSA renal scintigraphy. DMSA renal scintigraphy was performed at 1 and 6 months after UTI.

RESULTS

Of 67 children, 17 (25.4%), 23 (34.3%) and 20 (29.9%) had vesicoureteral reflux (VUR), abnormal renal ultrasonography and abnormal DMSA renal scintigraphy, respectively. Unilateral hydronephrosis had a significant correlation with VUR at p value 0.024. In renal units, abnormal renal ultrasonography and hydronephrosis had significant correlations with VUR at p values 0.039 and 0.021, respectively. In patients and renal units, hydronephrosis had no significant correlation with abnormal DMSA renal scintigraphy at 1 month after UTI. However, abnormal renal ultrasonography and VUR had significant correlations with abnormal DMSA renal scintigraphy at p values 0.022 and < 0.001 in patients and at p values 0.024 and < 0.001 in renal units, respectively. Both in patients and renal units, VUR (Grade I-III) had no significant correlation with abnormal DMSA renal scintigraphy. However, severe VUR (Grade IV-V) had significant correlations with abnormal DMSA renal scintigraphy at p values < 0.001 and < 0.001, respectively. Seventeen patients underwent DMSA renal scintigraphy at 6 months after UTI. In addition, 15 (88.2%) developed persistent renal scarring.

CONCLUSION

Abnormal renal ultrasonography and severe VUR identify renal parenchymal changes. DMSA renal scintigraphy in the first episode of UTI should be carried out in those patients. Abnormal DMSA renal scintigraphy at 1 month after UTI has a tendency to persist.

[Chronic limping due to calcification in a subureteric Macroplastique(®) implant]

Endoscopic subureteric implantation of polydimethylsiloxane (Macroplastique(®)) to treat vesico-ureteric reflux is known to be safe and efficient, but long-term complications of this technique are often unknown. A 15-year-old patient was admitted to several hospital services with abdominal pain in the right lower quadrant and chronic limping. After multiple examinations, the diagnosis of renal colic due to the calcification of a Macroplastique(®) implant was made. Calcification of an implant after endoscopic subureteral injection has already been described in the literature, but the clinical presentation of this complication is poorly reported, which can delay the diagnosis. The treatment can consist in an exeresis of the implanted material or even in ureteral reimplantation.

Does hydronephrosis predict the presence of severe vesicoureteral reflux?

We hypothesized that, in patients with vesicoureteral reflux (VUR) grade IV or V, hydronephrosis will likely be found, if the patient has a full bladder during the renal ultrasound examination. Eight hundred thirty-seven patients were included in the study. Patients ranged in age from <1 month to 18.7 years, with a median age of 1.3 years. Five hundred sixty-nine were female and 268 were male. In this retrospective study, each patient underwent a voiding cystourethrogram (VCUG) and a renal ultrasound examination. The presence of hydronephrosis and bladder filling status in 131 renal units with VUR grade IV or V was evaluated. Sensitivity and specificity for hydronephrosis to detect the presence of VUR grades IV and V were 60 and 92 %, respectively. Positive predictive value and negative predictive value were 74 and 87 %, respectively. Odds ratios for the relationship between hydronephrosis and severe VUR was significant (p = 0.046).

CONCLUSION

In patients with grade IV or V VUR, hydronephrosis will be observed in the presence of a full bladder. Therefore, a renal ultrasound could be considered a screening test to decide on performing a VCUG.

Intraureteral injection of NASHA/Dx gel under direct ureteroscopic visualization for the treatment of primary high-grade vesicoureteral reflux

OBJECTIVE

To present a preliminary experience with the modified technique of extravesical intraureteral injection of non-animal-stabilized hyaluronic acid/dextranomer (NASHA/Dx) gel under direct ureteroscopic visualization for the treatment of primary high-grade vesicoureteral reflux (VUR).

PATIENTS AND METHODS

The medical records of all pediatric patients (age range, 0-14 years) who underwent intraureteral injection of NASHA/Dx gel under direct ureteroscopic visualization for the treatment of primary high-grade VUR during the period June 2006-June 2010 were reviewed.

RESULTS

Eighty-nine children (61 boys, 28 girls; M:F ratio, 2.1) underwent intraureteral injection of NASHA/Dx gel under direct ureteroscopic visualization for the treatment of primary high-grade VUR during the study period. VUR completely disappeared after the injection of NASHA/Dx gel into 105 (73%) of 144 ureters, with no further treatment required. Thirty-five (24.3%) required a second injection, and 2 (1.4%) required a third injection for resolution of their VUR. No intraoperative complications were observed. No ureteral obstruction during follow-up was observed using ultrasound or micturition studies.

CONCLUSIONS

Intraureteral injection of NASHA/Dx gel under direct ureteroscopic visualization is safe and effective in the treatment of primary high-grade VUR, including cases with ureteral duplication, if the ureteral meatus is easy to pass through without mechanical dilation. This approach represents an effective and safe alternative to antibiotic prophylaxis alone and open surgery.

Genotypic Analysis of E. coli Strains Isolated from Patients with Cystitis and Pyelonephritis

BACKGROUND

Urinary tract infection is the most common health problem affecting millions of people each year, mainly caused by a large genetically heterogeneous group of Escherichia coli called uropathogenic E. coli This study investigates the genotypic analysis of E. coli strains isolated from patients with cystitis and pyelonephritis.

METHODS

During 2008-2009, 90 E. coli strains were analyzed, consisting of 48 isolates causing pyelonephritis in children and 42 isolates causing cystitis. Having identified the strains by standard methods, they were subtyped by pulsed field gel electrophoresis (PFGE) and their corresponding patterns were compared using dendrogram.

RESULTS

Sixty five PFGE profiles were obtained from the genome of E. coli strains by this genotyping method. Thirty six and thirty three patterns were obtained for pyelonephritis and cystitis, respectively. Most strains exhi-bited twelve and thirteen bands and the patterns with eight or nineteen bands had the lowest rate. Genome sizes of the strains were between 1610-4170 kbp.

CONCLUSION

With due attention to these results, genetic patterns showed that the strains had different clonalities and it could be suggested in some cases that the strains causing pyelonephritis or cystitis have common patterns and different diseases could be explained by different gene factors.

Incidence of febrile urinary tract infections in children after successful endoscopic treatment of vesicoureteral reflux: a long-term follow-up

OBJECTIVE

To evaluate the incidence of febrile urinary tract infection (UTI) after successful endoscopic correction of intermediate and high-grade vesicoureteral reflux (VUR).

STUDY DESIGN

Medical records of 1271 consecutive children (male, 411; female, 903) who underwent successful endoscopic correction of VUR were reviewed. Factors potentially influencing postoperative UTIs, such as history of presentation, age, sex, grade of VUR, renal scarring, and agent used for the endoscopic injection, were analyzed.

RESULTS

Febrile UTI developed in 73 children (5.7%) after successful endoscopic correction of VUR. Thirty-nine children had a single episode of UTI, and 34 children had two or more episodes at 1 month to 5.9 years (median, 1 year) after correction of VUR. With multivariate analysis, female sex (P < .001), history of preoperative bladder/bowel dysfunction (BBD; P = .005), and BBD after endoscopic correction (P = .001) were revealed to be the most important independent risk factors for a febrile UTI after successful correction of VUR.

CONCLUSIONS

The incidence of febrile UTIs after successful correction of intermediate and high grade VUR is low. Female sex and BBD were the most important risk factors in the development of febrile UTI. Our data supports the importance of assessing bladder and bowel habits in older children with febrile UTIs after endoscopic correction of VUR.

Screening high-grade vesicoureteral reflux in young infants with a febrile urinary tract infection

BACKGROUND

The lack of good evidence for improved outcomes in children and young infants with febrile urinary tract infection (UTI) after aggressive treatment for vesicoureteral reflux (VUR) has raised doubts regarding the need for routine voiding cystourethrography (VCUG), and the appropriate imaging evaluation in these children remains controversial.

OBJECTIVES

This prospective study aimed to determine whether abnormalities found on acute dimercaptosuccinic acid (DMSA) scan and ultrasound (US) can help indicate the necessity of voiding cystourethrography (VCUG) in young infants.

METHODS

For 3.5 years, all infants younger than 3 months presenting with first febrile UTI were prospectively studied. All infants were hospitalized and investigated using US (<3 days after admission), DMSA scan (<5 days after admission), and VCUG (7-10 days after antibiotic treatment) after diagnosis. The association among findings of US, DMSA scan, and VCUG were evaluated.

RESULTS

From 220 infants, there were abnormal results in 136 (61.8%) US and in 111 (50.5%) DMSA scans. By US, ten infants (4.5%) with abscess or structural abnormalities other than VUR were diagnosed. High-grade (III-V) VUR was present in 39 patients (17.7%). The sensitivities for high-grade VUR of renal US alone (76.9%) or DMSA scan alone (82.1%) were not as good as that of the "OR rule" strategy, which had 92.3% sensitivity and 94.3% negative predictive value.

CONCLUSIONS

To screen high-grade VUR in young infants with febrile UTI, US and acute DMSA scan could be performed first. VCUG is only indicated when abnormalities are apparent on either US or DMSA scan or both.

Is a routine voiding cystourethrogram necessary in children after the first febrile urinary tract infection?

AIM

The aim of this study was to estimate the value of identifying vesicoureteral reflux (VUR) on a voiding cystourethrogram (VCUG) and the benefit of VUR management according to imaging strategies at the first febrile urinary tract infection (UTI).

METHODS

Children aged 1-144 months (n = 618) with the first febrile UTI admitted at our hospital from 2000 to 2009 were enrolled. In all patients, renal sonogram (US), (99m) Tc-dimercaptosuccinic acid (DMSA) renal scanning and VCUG were performed. Retrospective analyses per patient and per renal unit were performed.

RESULTS

Abnormal US or DMSA scans had a sensitivity of 100% and a negative predictive value (NPV) of 100% to detect high-grade reflux. In hydronephrotic kidneys, DMSA scanning had a sensitivity of 88.2% and a NPV of 97.1% to detect high-grade reflux.

CONCLUSION

Routine VCUG is not required after the first febrile UTI in patients with normal US or normal DMSA scan. Even if the US reveals hydronephrosis, routine VCUG is not necessary if the DMSA findings are normal. It is recommended that children who did not receive both a DMSA scan and VCUG after the first febrile UTI should be followed up over the long term.

Utility of post-urinary tract infection imaging in patients with normal prenatal renal ultrasound

The American Academy of Pediatrics recommends renal ultrasound (RUS) and voiding cystourethrography (VCUG) for all infants after a first urinary tract infection (UTI). However, many congenital renal anomalies are identified by a prenatal US. At the present time, there are no data regarding the yield of post-UTI imaging among infants who have a documented normal prenatal US. We retrospectively reviewed the charts of all patients <1 year of age with a first UTI who had normal kidneys noted on prenatal US to determine the frequency of abnormal findings. Abnormal RUS and VCUG results were noted in 5.1% (24 of 471) and 20.4% (75 of 368) of infants, respectively. While the abnormal US rate is significantly less than what has been previously reported, the frequency of abnormal VCUGs is similar. These results suggest that a post-UTI RUS may not be needed if the prenatal US was normal. However, a VCUG continues to be indicated.

Randomized trial of oral versus sequential IV/oral antibiotic for acute pyelonephritis in children

OBJECTIVE

To confirm whether oral antibiotic treatment is as efficacious as sequential intravenous/oral antibiotic treatment in the prevention of renal scarring in children with acute pyelonephritis and scintigraphy-documented acute lesions.

METHODS

In a prospective multicenter trial, children aged 1 to 36 months with their first case of acute pyelonephritis, a serum procalcitonin concentration ≥0.5 ng/mL, no known uropathy, and a normal ultrasound exam were randomized into 2 treatment groups. They received either oral cefixime for 10 days or intravenous ceftriaxone for 4 days followed by oral cefixime for 6 days. Patients with acute renal lesions detected on early dimercaptosuccinic acid scintigraphy underwent a follow-up scintigraphy 6 to 8 months later.

RESULTS

The study included 171 infants and children. There were no significant differences between the 2 groups in any clinical characteristic. Initial scintigraphy results were abnormal for 119 children. Ninety-six children were measured for renal scarring at the follow-up scintigraphy (per protocol analysis population). The incidence of renal scarring was 30.8% in the oral treatment group and 27.3% for children who received the sequential treatment.

CONCLUSIONS

Although this trial does not statistically demonstrate the noninferiority of oral treatment compared with the sequential treatment, our study confirmed the results of previously published reports and therefore supports the use of an oral antibiotic treatment of primary episodes of acute pyelonephritis in infants and young children.