Age-related renal parenchymal lesions in children with first febrile urinary tract infections

National Trends in Voiding Cystourethrograms During Hospitalization for Young Infants With Urinary Tract Infections

OBJECTIVES

The American Academy of Pediatrics published a guideline in 2011 recommending against the routine use of voiding cystourethrogram (VCUG) in infants aged 2 to 24 months with first febrile urinary tract infection (UTI); however, the rates of VCUG for infants aged <2 months are unknown. The objective of this study was to determine the trend in VCUG performance during index hospitalization among infants aged 0 to 2 months with UTI.

METHODS

This retrospective cohort study included infants aged birth to 2 months hospitalized with a UTI from 2008 to 2019 across 38 institutions in the Pediatric Health Information System. Outcome measures included recurrent UTI within 1 year, vesicoureteral reflux diagnosis within 1 year and antiurinary reflux procedure performed within 2 years. Trends over time were compared between preguideline (2008-2011) and postguideline periods (2012-2019) using piecewise mixed-effects logistic regression.

RESULTS

The odds of VCUG decreased by 21% per year in the preguideline period (adjusted odds ratio, 0.79; 95% confidence interval, 0.77-0.81; P < .001) versus 20% (adjusted odds ratio, 0.80; 95% confidence interval, 0.77-0.83; P < .001) in the postguideline period. The preguideline and postguideline difference was not statistically significant (P = .60). There was no difference in the postguideline odds of UTI within 1 year (P = .07), whereas the odds of vesicoureteral reflux diagnosis (P < .001) and antiurinary reflux procedure performance (P < .001) decreased.

CONCLUSIONS

VCUG performance during hospitalization has declined over the past decade among young infants hospitalized with UTI. Further work is needed to determine the optimal approach to imaging in these young infants.

Can diagnostic and imaging recommendations from the 2011 AAP UTI guidelines be applied to infants <2 months of age?

INTRODUCTION

In 2011, the American Academy of Pediatrics (AAP) published guidelines regarding diagnosis and management of children 2-to-24-months-old with initial febrile urinary tract infection (fUTI). Available data were insufficient to determine whether evidence from studies of 2-to-24-month-olds applies to those <2-months-old, so they were excluded.

OBJECTIVE

This study aimed to 1) compare demographic, clinical, imaging and outcomes between patients <2-months-old and those 2-to-24-months-old hospitalized with fUTI, and 2) assess whether diagnostic and imaging recommendations of the AAP 2011 guidelines apply to those <2-months-old.

STUDY DESIGN

A cohort study of patients ≤24-months-old hospitalized at a children's hospital with fUTI from 2016 to 2018 was conducted. Data were collected via a prospectively generated electronic medical record note template, supplemented with retrospective chart review. Primary outcomes included differences in demographics, clinical presentation, urine culture results, and imaging utilization/results by age group. Secondary outcomes included surgical procedures, UTI recurrence, and 90-day all-cause readmissions and emergency department (ED) revisits. Univariate and bivariate statistics were utilized to compare age groups.

RESULTS

Overall, 137 patients were included (median age 70 days, 55.5% male [92.1% uncircumcised], 53.3% Hispanic/Latino, 89.8% 1st fUTI). There were no demographic differences between groups, except children <2-months-old were more frequently male (71.2 vs 43.6%, p = 0.002). The Summary Table compares clinical factors and imaging utilization by age. There were no differences in urinalysis or urine culture results between groups. Patients <2-months-old had shorter fever duration, lower maximum temperature, and lower white blood cell counts. Voiding cystourethrograms (VCUGs) were recommended and obtained more frequently in patients <2-months-old, but there were no differences in renal and bladder ultrasound (RBUS) or VCUG results between age groups. There were no differences in UTI recurrence (13.6% of <2-months-old vs 14.1% of 2-to-24-months-old, p = 1.00) or fUTI recurrence (13.6 vs 7.7%, p = 0.40) within 1 year, 90-day readmission (6.8 vs 6.4%, p = 1.00), or 90-day ED revisit (22.0 vs 20.5%, p = 1.00).

DISCUSSION

There were minimal differences between the <2-months-old and 2-to-24-months-old age groups in demographics, laboratory (including microbial) or imaging results, or clinical outcomes. Patients <2-months-old were more frequently male and less ill. These data support applying urinalysis and urine culture diagnostic criteria, and universal RBUS, from the AAP guidelines to patients <2-months-old. Given utilization differences, applicability of VCUG guideline recommendations requires further clarification for patients <2-months-old.

CONCLUSION

Laboratory testing and RBUS recommendations from the AAP guidelines may be safely applied to infants <2-months-old. Further studies are needed to clarify optimal VCUG recommendations.

"Parenteral" Diarrhea Associated With Pediatric Urinary Tract Infections: A Retrospective Chart Review

OBJECTIVES

The association of noninfectious diarrhea with extraintestinal infections such as otitis media, pneumonia, or febrile urinary tract infections (UTIs) is commonly known as parenteral diarrhea. Although this association has been described for over a century and parenteral diarrhea is mentioned in current reference literature, available evidence for this association seems to be limited. The primary research question was to determine if there is an association between UTIs and reports of diarrhea.

METHODS

A retrospective chart review was performed using the medical records from October 1, 2017, to March 29, 2019 at our tertiary pediatric medical center. We searched for all cases of afebrile and febrile UTIs evaluated in the pediatric emergency department or admitted directly to the hospital for treatment. All children younger than 5 years were eligible for inclusion. Exclusion criteria included children with recent urological procedures, known urinary tract disease, immune suppression, sepsis, or known gastrointestinal diseases. The medical records of each of the pediatric patients with culture-positive UTIs were reviewed for reports of concurrent diarrhea or diarrhea-like illness. In addition, using a comparative quantitative design, we performed a retrospective chart review of all children younger than 5 years with 1 of 2 noninfectious chief complaints, head trauma, and extremity fractures, presenting during the same period to assess the background rate of reported diarrhea.This research project received the approval of the University of South Alabama's Institutional Review Board.

RESULTS

A total of 236 children with a culture-positive UTI presented to our pediatric medical center from October 1, 2017 to March 29, 2019. Reports of diarrhea were documented in the medical record for 44 of the 236 UTIs (18.6%). Escherichia coli was the predominant infectious agent in 32 of the 44 children (72.7%) with culture-positive UTIs and diarrhea. Of the 368 comparison group patients who visited the pediatric emergency department for a noninfectious complaint, diarrhea was reported in 2 patients (0.01%).

CONCLUSIONS

Our retrospective review of pediatric patients younger than 5 years with culture-proven UTIs found an association of reported diarrhea. It is our opinion based on our single-center retrospective chart review that the current available evidence suggests an association between UTIs and extraintestinal diarrhea. Future prospective studies are recommended to confirm this association.

Nomogram for diagnosing acute pyelonephritis in pediatric urinary tract infection

BACKGROUND

For risk stratification and individualized treatment for children with urinary tract infection (UTI), they must be assessed for the presence of acute pyelonephritis (APN). Our study aimed to combine variables that can predict APN and establish a nomogram for clinical use.

METHODS

In total, 111 children <5 years old hospitalized at Kaohsiung Veterans General Hospital for UTI were classified into APN and simple UTI groups based on a technetium-99 m dimercaptosuccinic acid scan. Their demographic, laboratory test, and renal and urinary bladder sonography (RUBS) data were compared.

RESULTS

Fever peak of >39 °C, serum procalcitonin (PCT) ≥ 0.52 pg/mL, C-reactive protein (CRP) ≥ 2.86 mg/dL, and abnormal RUBS findings were independent variables for predicting APN in children. The nomogram established using the aforementioned variables had an area under the receiver operating characteristic curve (AUC) of 0.89, which was higher than those of PCT and CRP alone (0.776 and 0.774, respectively).

CONCLUSION

The combination of four variables had the highest power in predicting APN in children with UTI. The established nomogram is practical for clinical use.

Dexamethasone to prevent kidney scarring in acute pyelonephritis: a randomized clinical trial

BACKGROUND

Urinary tract infection (UTI) is one of the most common bacterial infections in childhood and is associated with long-term complications. We aimed to assess the effect of adjuvant dexamethasone treatment on reducing kidney scarring after acute pyelonephritis (APN) in children.

METHODS

Multicenter, prospective, double-blind, placebo-controlled, randomized clinical trial (RCT) where children from 1 month to 14 years of age with proven APN were randomly assigned to receive a 3-day course of either an intravenous corticosteroid (dexamethasone 0.30 mg per kg/day) twice daily or placebo. The late technetium 99 m-dimercaptosuric acid scintigraphy (> 6 months after acute episode) was performed to assess kidney scar persistence. Kidney scarring risk factors (vesicoureteral reflux, kidney congenital anomalies, or urinary tract dilatation) were also assessed.

RESULTS

Ninety-one participants completed the follow-up and were finally included (dexamethasone n = 49 and placebo n = 42). Both groups had similar baseline characteristics. Twenty participants showed persistent kidney scarring after > 6 months of follow-up without differences in incidence between groups (22% and 21% in the dexamethasone and placebo groups, p = 0.907). Renal damage severity in the early DMSA (β = 0.648, p = 0.023) and procalcitonin values (β = 0.065 p = 0.027) significantly modulated scar development. Vesicoureteral reflux grade showed a trend towards significance (β = 0.545, p = 0.054), but dexamethasone treatment showed no effect.

CONCLUSION

Dexamethasone showed no effect on reducing the risk of scar formation in children with APN. Hence, there is no evidence for an adjuvant corticosteroid treatment recommendation in children with APN. However, the study was limited by not achieving the predicted sample size and the expected scar formation.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT02034851. Registered in January 14, 2014. "A higher resolution version of the Graphical abstract is available as Supplementary information."

Serum neutrophil gelatinase-associated lipocalin for predicting acute pyelonephritis in infants with urinary tract infection

Introduction

Fever and elevated inflammatory markers have been used for diagnosis of acute pyelonephritis (APN) in infants with urinary tract infection (UTI).

The aim of the study was to compare the usefulness of serum neutrophil gelatinase-associated lipocalin (sNGAL) with inflammatory markers for predicting APN in infants with UTI.

Material and methods

The prospective study included 46 infants with a first episode of UTI, divided into two groups (APN 23, lower UTI 23), according to the DMSA scan results. The following laboratory tests were performed: sNGAL, PCT, CRP, WBC, and ESR.

Results

Significantly elevated levels of sNGAL, PCT, CRP, and ESR were observed in infants with APN compared to those with lower UTI. Higher sNGAL, CRP, and ESR values, presence of fever, and longer duration of fever before antibiotic treatment were associated with APN [odds ratio (OR) 1.02, 1.27, 1.03, 13.46, 2.12, respectively]. Receiver operating characteristic (ROC) analysis showed better diagnostic profiles for sNGAL, PCT, and CRP than for ESR for predicting APN [area under the curve (AUC) 0.808, 0.819, 0.841, and 0.750, respectively]. The appropriate cut-off values of sNGAL, PCT and CRP were 100.8 ng/ml, 0.15 ng/ml, 5.3 mg/dl (all sensitivity and specificity 82.6%), and that of ESR was 40 mm/h (sensitivity 78.3%, specificity 60.9%).

Conclusions

sNGAL shows similar usefulness as PCT and CRP for predicting APN in infants with UTI, the diagnostic value of ESR is smaller, and WBC is not useful at all. The presence of fever and longer duration of fever are important predictors of APN in infants with UTI.

Antimicrobial misuse in pediatric urinary tract infections: recurrences and renal scarring

Background

In children, urinary tract infection (UTI) is one of a common bacterial infection. This study was conducted to detect the uropathogen, antimicrobial susceptibility, pathogen associated with recurrences and renal scarring in children initially taken care from general practitioners and later presented to tertiary care.

Methods

Every inward UTI episode, culture and antimicrobial susceptibility was done while on past 6-month, history of infections and use of antimicrobials was collected using clinical records and demonstration of antimicrobials. Children with recurrent pyelonephritis was followed and in vitro bio film formation was assessed.

Results

Frequency of UTI was significantly high among infants (p = 0.03). Last 6-month, all (220) were exposed to antimicrobials. Cefixime was the commonly prescribed antimicrobial (p = 0.02). In current UTI episode, 64.5% (142/220) of children with UTI were consulted GPs’ prior to seek treatment from tertiary care pediatric unit (p = 0.02). While on follow up child who developed UTI, found urine culture isolates were significantly shifted from E. coli and K. pneumoniae to extended spectrum of beta-lactamase (ESBL) E. coli and K. pneumoniae. Out of 208 participants, 36 of them had re-current pyelonephritis (R-PN). Renal scarring (RS) was detected in 22 out of 70 patients with pyelonephritis following dimercaptosuccinic acid scan. Following each episodes of recurrent pyelonephritis 11% of new scar formation was detected (p = 0.02). Bio film forming E. coli and K. pneumoniae was significantly associated in patients with R-PN (p = 0.04).

Discussion

Medical care providers often prescribe antimicrobials without having an etiological diagnosis. While continuing exposure of third generation cephalosporin and carbapenem leads to development of ESBL and CRE microbes in great. The empiric uses of antimicrobials need to be stream lined with local epidemiology and antimicrobial susceptibility pattern. R-PN in childhood leads to RS. In great, bio film formation act as the focus for such recurrences.

The impact of obesity on febrile urinary tract infection and renal scarring in children with vesicoureteral reflux

INTRODUCTION

It has become clear that obesity is associated with a variety of infectious diseases, including urinary tract infection (UTI) and renal scarring.

OBJECTIVE

The aim of this study was to evaluate the association between obesity and the degree of febrile UTI (fUTI) and renal scarring in children with vesicoureteral reflux (VUR), and to stratify the results into obesity subcategories.

STUDY DESIGN

A total of 186 patients were diagnosed with VUR between January 2002 and December 2008. This study retrospectively reviewed the medical records of 72 children with primary VUR who had recurrent fUTI (more than twice). Overweight or obese status of the patients aged <2 years was defined using weight-for-length (WFL) measurements. For 2-5 year old children, body mass index (BMI) percentile-for-age was used. They were divided into three groups as follows; standard (<85%), overweight (85-95%), and obese (≥95%). The following clinical variables were compared: age at diagnosis of primary VUR (months), sex, VUR grade, hydronephrosis grade, presence of renal scarring, surgical treatment, and degree of inflammation during fUTI.

RESULTS

In the overweight and obese groups, VUR was diagnosed at a young age (P = 0.05), the degree of renal scarring was more severe (P = 0.006), and serum white blood cell count, C-reactive protein, and erythrocyte sedimentation rate (ESR) levels were significantly higher (P < 0.001, P < 0.001, and P < 0.001, respectively). Abnormal focal dimercaptosuccinic acid (DMSA) defects were present in 25 of the 72 children (35%). Cortical defects occurred more frequently in children with obesity, and they were associated with a higher grade of reflux and serum ESR levels (P = 0.007, P = 0.042, and P = 0.021, respectively). Among these risk factors, high-grade VUR (OR = 9.93, 95% CI = 1.13-86.71), and being overweight and obese (OR = 5.26, 95% CI = 1.75-15.82) were associated with increased renal scarring. However, ESR was not associated with renal scarring (OR = 1.01, 95% CI = 0.95-1.07).

DISCUSSION

The relationships between obesity and UTI are controversial. Some studies have shown positive results; however, other studies have shown opposite results. The main limitations of this study were the retrospective data collection via electronic medical records, and the small number of subjects.

CONCLUSIONS

This study showed that obesity in patients with VUR has an effect on fUTI and renal scar formation. If the patients with VUR have obesity, close follow-up should be performed, and VUR patients should be started on a weight-loss program, which could reduce the number of patients with chronic kidney disease in the future.

Urine interleukin-6, interleukin-8 and transforming growth factor β1 in infants with urinary tract infection and asymptomatic bacteriuria

INTRODUCTION

Urinary tract infection (UTI) occurs in 1.1% of girls and 1.4% of boys during the first year of life. Asymptomatic bacteriuria (ABU) is usually detected incidentally in 0.9% of girls and 2.5% of boys at this age. The aim of the study was to assess the usefulness of measurement of pro-inflammatory urine interleukin (IL)-6 and IL-8 concentrations and anti-inflammatory transforming growth factor β1 (TGF-β1) level in infants with febrile UTI, non-febrile UTI and ABU.

MATERIAL AND METHODS

A total of 35 children, mean age 6.14 ±3.47 months, were divided into three groups: group I - febrile UTI (n = 13), group II - non-febrile UTI (n = 13) and group III - ABU (n = 9). At the time of enrollment urine IL-6, IL-8, TGF-β1 and serum C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and white blood cell count (WBC) were measured. Renal ultrasound was performed in all children, 99mTc-dimercaptosuccinic acid scintigraphy (DMSA) and voiding cystourethrography in children with UTI.

RESULTS

Urine concentrations of IL-6 and IL-8 were significantly higher in febrile UTI compared to those with non-febrile UTI and ABU (p < 0.5, p < 0.01) and positively correlated with CRP, ESR and WBC (p < 0.01). Urine levels of TGF-β1 were significantly higher in children with febrile UTI compared to those with ABU (p < 0.05) and positively correlated with WBC (p < 0.01). Inflammatory changes in the DMSA scan were detected in 66.6% of children with UTI. No significant difference in frequency of an abnormal DMSA scan compared to a normal scan was found in groups with febrile and non-febrile UTI. No relations between urine cytokines, systemic inflammatory markers and changes in DMSA scan were observed. The cutoff value for detection of inflammatory changes in the DMSA scan for IL-8 was 120 pg/mg creatinine (Cr) and 40 pg/mg Cr for TGF-β1. Based on this value, the sensitivity for IL-8 was 58.3%, specificity 100% and for TGF-β1 66.7% and 83.7%, respectively.

CONCLUSIONS

We found significant differences in children with febrile UTI and ABU regarding urine IL-6, IL-8 and TGF-β1 levels. Urine cytokines and systemic inflammatory markers do not differentiate between upper and lower UTI in infants.

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.

Vesicoureteral refux detection in children: a comparison of the midline-to-orifice distance measurement by ultrasound and voiding urosonography

BACKGROUND

Due to the questionable clinical role of vesicoureteral reflux (VUR) and the search for noninvasive, radiation-free procedures sufficiently reliable to detect VUR, we compared the correlation between the midline-to-orifice distance (MOD) measured by ultrasonography (US) and echo-enhanced voiding urosonography (VUS) for detecting VUR in children. The aim of the study was to determine whether measuring MOD by US could be a reliable predictor of VUR in children.

METHODS

A total of 116 children, aged 0.25-84 months, with 232 potentially refluxing units were investigated simultaneously by measuring the MOD and performing VUS. Indications for cystography were urinary tract infection and follow-up of a previously detected VUR. VUS was performed after the MOD measurement. The results were analyzed with VUS as the reference method.

RESULTS

The MOD was significantly larger in VUR grade III (10.7 mm; p = 0.003) and VUR grade II (9.9 mm; p = 0.001) refluxing units than in non-refluxing units (7.8 mm), even when controlling for the estimated volume/expected maximal capacity (Vest/Vmax) ratio. A MOD cutoff value of 7.4 mm was chosen as a predictor of either the presence or absence of VUR; the sensitivity and specificity of this cutoff measurement for VUR detection were found to be 89 and 24%, respectively.

CONCLUSIONS

Despite the statistically significant difference between the MOD of refluxing versus non-refluxing units identified in our study, the MOD measurement needs further evaluation to determine its potential value as a diagnostic tool for the detection of VUR.

Predictors of Antimicrobial Resistance among Pathogens Causing Urinary Tract Infection in Children

OBJECTIVE

To determine which children with urinary tract infection are likely to have pathogens resistant to narrow-spectrum antimicrobials.

STUDY DESIGN

Children, 2-71 months of age (n = 769) enrolled in the Randomized Intervention for Children with Vesicoureteral Reflux or Careful Urinary Tract Infection Evaluation studies were included. We used logistic regression models to test the associations between demographic and clinical characteristics and resistance to narrow-spectrum antimicrobials.

RESULTS

Of the included patients, 91% were female and 76% had vesicoureteral reflux. The risk of resistance to narrow-spectrum antibiotics in uncircumcised males was approximately 3 times that of females (OR 3.1; 95% CI 1.4-6.7); in children with bladder bowel dysfunction, the risk was 2 times that of children with normal function (OR 2.2; 95% CI 1.2-4.1). Children who had received 1 course of antibiotics during the past 6 months also had higher odds of harboring resistant organisms (OR 1.6; 95% CI 1.1-2.3). Hispanic children had higher odds of harboring pathogens resistant to some narrow-spectrum antimicrobials.

CONCLUSIONS

Uncircumcised males, Hispanic children, children with bladder bowel dysfunction, and children who received 1 course of antibiotics in the past 6 months were more likely to have a urinary tract infection caused by pathogens resistant to 1 or more narrow-spectrum antimicrobials.

Renal Scarring in the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) Trial

BACKGROUND AND OBJECTIVES

The main objectives of the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) trial were to evaluate the role of antimicrobial prophylaxis in the prevention of recurrent urinary tract infection (UTI) and renal scarring in children with vesicoureteral reflux (VUR). We present a comprehensive evaluation of renal scarring outcomes in RIVUR trial participants.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This multicenter, randomized, placebo-controlled trial enrolled 607 children aged 2-71 months with grade 1-4 VUR diagnosed after a first or second febrile or symptomatic UTI. Study participants received trimethoprim-sulfamethoxazole or placebo and were followed for 2 years. Renal scarring was evaluated by baseline and follow-up (99m)technetium dimercaptosuccinic acid (DMSA) renal scans that were reviewed independently by two blinded reference radiologists.

RESULTS

At the end of the study, 58 (10%) of 599 children and 63 (5%) of 1197 renal units had renal scarring. New renal scarring did not differ between the prophylaxis and placebo groups (6% versus 7%, respectively). Children with renal scarring were significantly older (median age, 26 versus 11 months; P=0.01), had a second UTI before enrollment (odds ratio [OR], 2.85; 95% confidence interval [95% CI], 1.38 to 5.92), were more likely to be Hispanic (OR, 2.22; 95% CI, 1.13 to 4.34), and had higher grades of VUR (OR, 2.79; 95% CI, 1.56 to 5.0). The proportion of new scars in renal units with grade 4 VUR was significantly higher than in units with no VUR (OR, 24.2; 95% CI, 6.4 to 91.2).

CONCLUSIONS

Significantly more renal scarring was seen in relatively older children and in those with a second episode of febrile or symptomatic UTI before randomization. Preexisting and new renal scars occurred significantly more in renal units with grade 4 VUR than in those with low-grade or no VUR. Antimicrobial prophylaxis did not decrease the risk of renal scarring.

Renal damage detected by DMSA, despite normal renal ultrasound, in children with febrile UTI

OBJECTIVES

2011 American Academy of Pediatrics guidelines recommended renal-bladder ultrasound (RBUS) as the only evaluation after febrile urinary tract infection (FUTI) in infants aged 2-24 months. We determined the sensitivity, specificity, and false negative rate of RBUS to identify DMSA-detected renal damage in this age group as well as in older children.

METHODS

Consecutive patients referred to pediatric urology with a history of FUTI underwent DMSA ≥ 3 months after FUTI. Abnormal RBUS was defined as: Society of Fetal Urology hydronephrosis grades I-IV; hydroureter ≥ 7 mm; renal scar defined as focal parenchymal thinning; and/or size discrepancy ≥ 1 cm between kidneys. Abnormal DMSA was presence of any focal uptake defects and/or split renal function < 44%. We calculated sensitivity, specificity, positive and negative predictive values, and false negative rates of RBUS compared to DMSA.

RESULTS

618 patients (79% female), median age 3.4 years, were referred for FUTIs. Of the 512 (83%) with normal RBUS, 99 (19%) had abnormal DMSA. Children with normal RBUS after their first FUTI had abnormal DMSA in 15/151 (10%) aged ≤ 24 months and 23/119 (19%) aged > 24 months. RBUS had poor sensitivity (34%) and low positive predictive value (47%) to identify patients with renal damage. 99/149 (66%) children with renal damage on DMSA had normal RBUS.

CONCLUSION

After FUTI, 66% of children with reduced renal function and/or renal cortical defects found by DMSA scintigraphy had a normal RBUS. Since abnormal DMSA may correlate with increased risk for VUR, recurrent FUTI and renal damage, our data suggest RBUS alone will fail to detect a significant proportion of patients at risk. The data suggest that imaging after FUTI should include acute RBUS and delayed DMSA, reserving VCUG for patients with abnormal DMSA and/or recurrent FUTI.

Clinical and laboratory indices of severe renal lesions in children with febrile urinary tract infection

AIM

To evaluate the predictive value of various clinical and laboratory parameters on the identification of acute extensive and/or multifocal renal involvement in children with febrile urinary tract infections (UTI).

METHODS

The medical records of 148 children (median age: 2.4 months, range: 11 days-24 months), who were admitted during a 3-year period with a first episode of febrile UTI, were analysed. Acute dimercaptosuccinic acid scintigraphy (DMSA), clinical and laboratory parameters were evaluated.

RESULTS

Seventy six children (51%) had abnormal findings on the acute DMSA. Of them, 20 had DMSA grade 2, while 56 had grade 3 and 4. Patients with a DMSA grade 3 and 4 were more likely to have shivering (OR 3.4), white blood count (WBC) ≥ 18 000/μL (OR 2.4), absolute neutrophil count (ANC) ≥ 9300/μL (OR 4.4), C-reactive protein (CRP) ≥ 50 mg/L (OR 2.7) and procalcitonin (PCT) ≥ 1.64 ng/mL (OR diagnostic). There was a significant difference of WBC (p = 0.004), ANC, CRP and PCT levels (p < 0.001) between children with normal and grade 2 aDMSA versus those with aDMSA grade 3 and 4.

CONCLUSIONS

Shivering and elevated inflammatory markers increase the risk of acute extensive and/or multifocal kidney involvement in children with febrile UTI. Procalcitonin seems to be an excellent marker of the severity of acute parenchymal involvement.

Automated urinalysis and urine dipstick in the emergency evaluation of young febrile children

OBJECTIVE

The performance of automated flow cytometric urinalysis is not well described in pediatric urinary tract infection. We sought to determine the diagnostic performance of automated cell counts and emergency department point-of-care (POC) dipstick urinalyses in the evaluation of young febrile children.

METHODS

We prospectively identified a convenience sample of febrile pediatric emergency department patients <48 months of age who underwent urethral catheterization to obtain POC and automated urinalyses and urine culture. Receiver operating characteristic analyses were performed and diagnostic indices were calculated for POC dipstick and automated cell counts at different cutpoints.

RESULTS

Of 342 eligible children, 42 (12%) had urinary bacterial growth ≥ 50000/mL. The areas under the receiver operating characteristic curves were: automated white blood cell count, 0.97; automated bacterial count, 0.998; POC leukocyte esterase, 0.94; and POC nitrite, 0.76. Sensitivities and specificities were 86% and 98% for automated leukocyte counts ≥ 100/μL and 98% and 98% for bacterial counts ≥ 250/μL. POC urine dipstick with ≥ 1+ leukocyte esterase or positive nitrite had a sensitivity of 95% and a specificity of 98%. Combinations of white blood cell and bacterial counts did not outperform bacterial counts alone.

CONCLUSIONS

Automated leukocyte and bacterial counts performed well in the diagnosis of urinary tract infection in these febrile pediatric patients, but POC dipstick may be an acceptable alternative in clinical settings that require rapid decision-making.

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.

Urinary concentration of cytokines in children with acute pyelonephritis

Urinary tract infection (UTI) is a common bacterial infection among infants and children. Predicting which children with upper UTI will develop long-term sequelae remains difficult. We aimed at evaluating the predictive value of urine concentrations of interleukin-6 (UIL-6) and interleukin-8 (UIL-8) in subsequent renal scarring. In the current observational prospective study, urine samples for UIL-6 and UIL-8 were obtained from two groups: 31 children with first episode of febrile UTI and 22 febrile children of other origin. UIL-6 and UIL-8 were increased in children with febrile UTI, compared to children with fever of other origin [median and range (picograms per milliliter): (1) UIL-6, 74.46 (0-168) vs. 10.51 (0-47.50), respectively, p = 0.0001; (2) UIL-8, 2,660.38 (0-13,801) vs. 0, respectively, p = 0.0001]. Renal scarring was found in 5/31 (16 %) children with acute pyelonephritis. Initial median UIL-8 values were significantly higher in children with later renal scarring than in those without renal scarring [median and range (picograms per milliliter): 6,163 (2,021-13,801) vs. 1,490.5 (0-5,737), respectively, p = 0.018]. In conclusion, UIL-8 might serve as a predictive biomarker for renal scarring after an acute episode of pyelonephritis. Since UIL-8 emerges as a renal-specific diagnostic and prognostic marker, it may be suitable as a selective screening tool for children with febrile UTI.

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.

Renal scar formation after urinary tract infection in children

Urinary tract infection (UTI) is a common bacterial illness in children. Acute pyelonephritis in children may lead to renal scarring with the risk of later hypertension, preeclampsia during pregnancy, proteinuria, and renal insufficiency. Until now, vesicoureteral reflux (VUR) has been considered the most important risk factor for post-UTI renal scar formation in children. VUR predisposes children with UTI to pyelonephritis, and both are associated with renal scarring. However, reflux nephropathy is not always acquired; rather, it reflects reflux-associated congenital dysplastic kidneys. The viewpoint that chronic kidney disease results from renal maldevelopment-associated VUR has led to questioning the utility of any regimen directed at identifying or treating VUR. Despite the recognition that underlying renal anomalies may be the cause of renal scarring that was previously attributed to infection, the prevention of renal scarring remains the goal of all therapies for childhood UTI. Therefore, children at high risk of renal scar formation after UTI should be treated and investigated until a large clinical study and basic research give us more information.

Urinary tract infection in infants: a single-center clinical analysis in southern Taiwan

BACKGROUND

This study summarized the epidemiology, etiology, and susceptibility of pathogens to antibiotics, and specific characteristics in infants aged less than 4 months diagnosed with urinary tract infection in the past decade in Taiwan.

METHODS

The medical charts of patients aged less than 4 months admitted for urinary tract infection to Kaohsiung Veterans General Hospital between January 2001 and December 2009 were retrospectively reviewed.

RESULTS

A total of 132 patients, with male predominance (68.9%), were enrolled. The top three pathogens were similar to those identified in previous studies in Taiwan. The most common pathogen, Escherichia coli (85.3%), was resistant to ampicillin (75.9%), followed by sulfamethoxazole/trimethoprim (31.7%), and cefazolin (28.5%). Dimercaptosuccinic acid (DMSA) renal scan revealed 34.5% positive findings, while the vesicoureteral reflux (VUR) rate was 37.8% by direct radionuclide voiding cystography and/or voiding cysto-urethrography. Positive DMSA findings significantly correlated with VUR (p<0.001) and higher C-reactive protein level (p<0.05).

CONCLUSIONS

E coli was the most common pathogen in the present cohort, and the top three pathogens were similar to those found in general pediatric population in Taiwan. VUR was the most common genitourinary tract anomaly in this age group. Positive DMSA was well correlated with VUR and higher C-reactive protein level.

Observation of patients with vesicoureteral reflux off antibiotic prophylaxis: physician bias on patient selection and risk factors for recurrent febrile urinary tract infection

PURPOSE

Observation off continuous antibiotic prophylaxis is an option for vesicoureteral reflux. We evaluated the characteristics of patients observed off continuous antibiotic prophylaxis and risk factors for febrile urinary tract infection.

MATERIALS AND METHODS

We identified children 1 to 18 years old with primary vesicoureteral reflux between January 1, 2010 and December 31, 2010. We excluded patients with prior surgical correction from analysis. We recorded age, gender, race/ethnicity, primary language, insurance carrier, age at vesicoureteral reflux diagnosis, initial presentation and vesicoureteral reflux severity. We quantified bladder and bowel dysfunction with a validated questionnaire if toilet trained. We compared patients off vs on continuous antibiotic prophylaxis with the chi-square test for categorical variables and the Mann-Whitney U test for continuous variables. We used a univariate Cox proportional hazards model to assess predictors of febrile urinary tract infection during observation off continuous antibiotic prophylaxis.

RESULTS

Of 529 eligible patients 224 were observed off continuous antibiotic prophylaxis. Patients off continuous antibiotic prophylaxis tended to be older (p <0.001), to be older at diagnosis (p <0.001), to have an initial presentation other than febrile urinary tract infection (p = 0.05), to have nondilating vesicoureteral reflux on most recent cystogram (p <0.001) and to have lower bladder/bowel dysfunction scores if toilet trained (p <0.001). Of the patients off continuous antibiotic prophylaxis a febrile urinary tract infection developed in 19 (8.5%). Risk factors associated with febrile urinary tract infection included initial presentation of multiple febrile urinary tract infections (p = 0.03), older age at diagnosis (p = 0.03) and older age starting observation off continuous antibiotic prophylaxis (p = 0.0003).

CONCLUSIONS

Criteria to select patients with vesicoureteral reflux for observation off continuous antibiotic prophylaxis remain poorly defined in the literature. Observation will fail in a subset of patients with vesicoureteral reflux. Physician biases regarding patient selection for observation off continuous antibiotic prophylaxis should be considered when interpreting studies that evaluate treatment strategies.

Issues in febrile urinary tract infection management

Urinary tract infections are common occurrences in the pediatric age group and are a cause of significant morbidity and expense. The understanding of the consequences and sequelae of febrile urinary tract infections led to revision of standard protocols initiated by the American Academy of Pediatrics (AAP) in 1999. A less invasive protocol of radiologic evaluation has been the major outcome of the revised AAP guidelines. Emphasis on prevention of recurrent febrile urinary tract infections has also led to therapeutic programs that are centered less around the use of prophylactic antibiotics than has previously been the practice.

Quality of life in children with vesicoureteral reflux

Vesicoureteral reflux (VUR) is commonly diagnosed in children presenting with urinary tract infections. Antibiotic prophylaxis and ureteric surgery are standard treatments for these children. Our aim was to investigate whether health-related quality of life (HRQOL) was altered in children treated for VUR. Children aged 1-5 years with grade III or higher VUR were identified through electronic records at the Stollery Children's Hospital. Parents of these children were mailed the TNO-AZL Netherlands Organisation for Applied Scientific Research Academic Medical Centre Quality of Life (TAPQOL) questionnaire. QOL scores for this group were compared with normative controls from the instrument's creators using the Mann-Whitney U test. Thirty-two of the 96 (33%) mailed surveys were returned. Eight children had surgery, and 19 were treated with antibiotic prophylaxis. When comparing the VUR group with the control group, we found that anxiety and social functioning scores were significantly better in patients with VUR (p < 0.01). The VUR group had worse scores in problem behavior, stomach complaints ,and communication (p < 0.01). This study reveals that children with VUR have a reasonable QOL when compared with controls. However, the diagnosis of VUR and its management does have an impact on gastrointestinal complaints, behavior, and communication, which may occur as a result of chronic medical intervention.

Risk factors for renal scar formation in infants with first episode of acute pyelonephritis: a prospective clinical study

PURPOSE

We prospectively determined the risk factors for renal scar formation after the first episode of acute pyelonephritis as confirmed on dimercapto-succinic acid scintigraphy in children younger than 1 year.

MATERIALS AND METHODS

A total of 213 infants with acute pyelonephritis were enrolled in the study. Infants with urological abnormalities other than vesicoureteral reflux were excluded from analysis. Followup scanning was performed 6 months after acute pyelonephritis and voiding cystourethrography was performed after the acute phase of infection. Possible risk factors were evaluated including gender, peak fever, duration of fever before and after treatment with antibiotics, white blood cell count, C-reactive protein concentration, presence of vesicoureteral reflux and reflux grade.

RESULTS

Six months after acute pyelonephritis 37 of 213 (17.4%) infants and 41 of 248 (16.5%) renal units with acute photon defects on initial dimercapto-succinic acid scintigraphy had renal scars. The rates of scar formation were significantly higher in infants with vesicoureteral reflux than in those without (39.4% vs 7.5%, p <0.001, OR 9.433) and in renal units with vesicoureteral reflux than in those without (39.4% vs 8.2%, p <0.001, OR 7.237). Renal scar formation was related to reflux grade (none-8.2%, grade I-20%, grade II-22.7%, grade III-40%, grade IV-70%, grade V-55.6%, p <0.001) but not to any other clinical or laboratory variables.

CONCLUSIONS

The presence of vesicoureteral reflux was the only independent risk factor for renal scar formation after acute pyelonephritis in infants. The prevalence of renal scarring was significantly correlated with reflux grade. Voiding cystourethrography is necessary in infants after the first acute pyelonephritis episode is confirmed on dimercapto-succinic acid renal scintigraphy.

Difficulties in diagnosing urinary tract infections in small children

Urinary tract infections (UTIs) in children appear to be simple and straightforward matters, but there is as yet no consensus on UTIs in this patient group, and it remains one of the most - if not the most - controversial fields in paediatric medicine. Controversy and the lack of consensus can be found in many areas, including the diagnosis and management of UTIs in paediatric patients. Consequently, children with a UTI are investigated and treated quite differently in different parts of the world and also within different parts of the same country. One factor contributing to the current situation is the unexpected difficulty in diagnosing a UTI in children. This difficulty has implications not only for clinical work but also for scientific studies. Substantial over- and under-diagnosing can result from practical difficulties in at least three areas, including problems with collecting urine samples, in interpreting bacterial numbers correctly, and in confusing infantile asymptomatic bacteriuria and a true symptomatic febrile UTI. In this review, these problems will be discussed in detail as well as the implications they have had on clinical practice and research on UTIs.

Vesicoureteral reflux and reflux nephropathy

Primary vesicoureteral reflux (VUR) is the commonest congenital urological abnormality in children, which has been associated with an increased risk of urinary tract infection (UTI) and renal scarring, also called reflux nephropathy (RN). In children, RN is diagnosed mostly after UTI (acquired RN) or during follow-up for antenatally diagnosed hydronephrosis with no prior UTI (congenital RN). The acquired RN is more common in female children, whereas the congenital RN is more common in male children. This observation in children might help explain the differences in the clinical presentation of RN in adults, with males presenting mostly with hypertension, proteinuria, and progressive renal failure as compared with females who present mostly with recurrent UTI and have a better outcome. Known risk factors for RN include the severity of VUR, recurrent UTI, and bladder-bowel dysfunction; younger age and delay in treatment of UTI are believed to be other risk factors. Management of VUR is controversial and includes antimicrobial prophylaxis, surgical intervention, or surveillance only. No evidence-based guidelines exist for appropriate follow-up of patients with RN.