Probabilities of Dilating Vesicoureteral Reflux in Children with First Time Simple Febrile Urinary Tract Infection, and Normal Renal and Bladder Ultrasound

Predictors of Abnormal Renal Ultrasonography in Children With Urinary Tract Infection

BACKGROUND AND OBJECTIVES

The 2011 American Academy of Pediatrics guidelines recommended a renal and bladder ultrasound (RBUS) after the first febrile urinary tract infection (UTI) in infants. Abnormal RBUS findings may be due to inflammation from the acute UTI or from vesicoureteral reflux (VUR), which may require a voiding cystourethrogram (VCUG) to diagnose, increasing health care costs. Our objective was to evaluate the effect of timing of imaging relative to the acute illness on abnormal dilation on RBUS and VCUG findings.

METHODS

Multicenter, retrospective study of patients aged 2 to 24 months presenting with first UTI and RBUS from January 1, 2015, to December 31, 2019. Demographics, isolated pathogen, and timing of RBUS and VCUG relative to urine culture date were recorded and compared.

RESULTS

A total of 227 patients were included. On multivariable logistic regression, increased time in days to RBUS was associated with decreased odds of abnormal dilation (adjusted odds ratio, 0.980; P = .018) in those patients meeting culture criteria for UTI (for each additional day of delay in obtaining RBUS, the adjusted odds of detecting dilation decreased by ∼2%). There was no significant association between timing of imaging and VUR on VCUG. Additionally, 32% of patients underwent RBUS who did not meet UTI culture criteria but had similar rates of abnormal dilation and VUR to those meeting UTI culture criteria.

CONCLUSIONS

Increased time to RBUS led to decreased odds of abnormal dilation, suggesting that delaying RBUS may lead to fewer false-positive results, which may limit unnecessary additional testing and reduce health care costs. Additionally, a significant number of patients who did not meet UTI culture criteria underwent RBUS but had similar results to those meeting criteria, suggesting that the previous colony-forming unit definition for UTI may be suboptimal.

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

OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

DISCUSSION

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

CONCLUSIONS

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

Vesico-ureteral reflux diagnosis after initial kidney abscess: Results from a Paediatric Tertiary Hospital

AIMS

Guidelines regarding voiding cystourethrogram (VCUG) indications following a paediatric kidney abscess are lacking. This study evaluates vesicoureteral reflux (VUR) prevalence and outcome after a first kidney abscess.

METHODS

This retrospective study included all children presenting to a tertiary paediatric reference centre with de-novo kidney abscesses from 2011 to 2022, diagnosed through imaging (ultrasonography or computed tomography). VCUG's clinical utility was assessed by exploring outcomes related to interventions.

RESULTS

Among the 17 patients (median age 9 months, IQR; 6 months-6 years), VCUG identified VUR in 7 (41%; 95% CI: 18-65%), including two with grade IV-V. Median abscess size was 19 mm (IQR; 14-27). 7/8 (88%) children with DMSA scan presented scars, including 4 with hypofunctioning (20%-44%), and one with a non-functioning kidney. Scarring on the DMSA scan was similar regardless of identified VUR. Six children had subsequent pyelonephritis. Three of the remaining 11 had grade I-III and two IV-V VUR. Surgery was required in four children overall: three for recurrent pyelonephritis and one for high-grade VUR and scars.

CONCLUSION

Among initial kidney abscess cases, 41% had VUR, similar to children experiencing their first uncomplicated pyelonephritis. VCUG results guided antibiotic prophylaxis but not surgical decisions. We suggest considering VCUG following recurrent pyelonephritis/kidney abscess and/or kidney scarring.

Evidence-based clinical practice guideline for management of urinary tract infection and primary vesicoureteric reflux

We present updated, evidence-based clinical practice guidelines from the Indian Society of Pediatric Nephrology (ISPN) for the management of urinary tract infection (UTI) and primary vesicoureteric reflux (VUR) in children. These guidelines conform to international standards; Institute of Medicine and AGREE checklists were used to ensure transparency, rigor, and thoroughness in the guideline development. In view of the robust methodology, these guidelines are applicable globally for the management of UTI and VUR. Seventeen recommendations and 18 clinical practice points have been formulated. Some of the key recommendations and practice points are as follows. Urine culture with > 104 colony forming units/mL is considered significant for the diagnosis of UTI in an infant if the clinical suspicion is strong. Urine leukocyte esterase and nitrite can be used as an alternative screening test to urine microscopy in a child with suspected UTI. Acute pyelonephritis can be treated with oral antibiotics in a non-toxic infant for 7-10 days. An acute-phase DMSA scan is not recommended in the evaluation of UTI. Micturating cystourethrography (MCU) is indicated in children with recurrent UTI, abnormal kidney ultrasound, and in patients below 2 years of age with non-E. coli UTI. Dimercaptosuccinic acid scan (DMSA scan) is indicated only in children with recurrent UTI and high-grade (3-5) VUR. Antibiotic prophylaxis is not indicated in children with a normal urinary tract after UTI. Prophylaxis is recommended to prevent UTI in children with bladder bowel dysfunction (BBD) and those with high-grade VUR. In children with VUR, prophylaxis should be stopped if the child is toilet trained, free of BBD, and has not had a UTI in the last 1 year. Surgical intervention in high-grade VUR can be considered for parental preference over antibiotic prophylaxis or in children developing recurrent breakthrough febrile UTIs on antibiotic prophylaxis.

Revisiting the utility of prenatal ultrasound in the routine workup of first febrile UTI: A systematic review and meta-analysis of the negative predictive value of prenatal ultrasound for identification of urinary tract abnormalities after first febrile urinary tract infection in children

CONTEXT

The current EAU/ESPU and recently retired AAP pediatric UTI guidelines recommend renal bladder ultrasound after first febrile UTI in children to screen for structural abnormalities, regardless of findings on prenatal ultrasound.

OBJECTIVE

Test the hypothesis that a normal prenatal ultrasound could rule out urinary tract abnormality on post-UTI ultrasound.

DATA SOURCES

Medline, Embase, Cochrane Library.

STUDY SELECTION

Studies including pediatric patients with first febrile UTI who had both prenatal and post-UTI ultrasound.

DATA EXTRACTION

Anatomical abnormalities detected by prenatal and post-UTI ultrasound as reported per individual study criteria were extracted. Meta-analyses of 9 studies (2981 patients) were performed using a random-effects model and composite estimates of the negative predictive value (NPV) of prenatal ultrasound were calculated.

RESULTS

Overall summary NPV of prenatal ultrasound for all pediatric patients was 77%, with heterogeneity score (I2) 97.9%. Summary NPV of prenatal ultrasound for all patients under two years of age was similar at 75%, with I2 98.2% For the 4 studies to which we could apply a more stringent definition of abnormality, summary NPV was 85% and I2 97.5% for prediction of moderate post-UTI ultrasound abnormalities and summary NPV was 93% and I2 90.4% for severe abnormalities.

DISCUSSION

While we calculated an 85% NPV for a normal prenatal ultrasound to rule out significant postnatal abnormality as defined within individual studies, substantial heterogeneity amongst publications limited the precision of our estimates. This highlights the need for more rigorous investigations with attention to timing of ultrasound and the application of clinically meaningful definitions for abnormal prenatal and post-UTI studies. This may allow judicious use of prenatal ultrasound to guide clinical management for children with first febrile UTI and minimize redundant imaging with potential for false positive results. Until then, the current guidelines are justified based on the limited and heterogenous data from the currently available published studies.

Update of the EAU/ESPU guidelines on urinary tract infections in children

INTRODUCTION/BACKGROUND

Urinary tract infections (UTIs) are common in children and require appropriate diagnostic evaluation, management and follow-up.

OBJECTIVE

To provide a summary of the updated European Association of Urology (EAU) guidelines on Pediatric Urology, which were first published in 2015 in European Urology.

STUDY DESIGN

A structured literature review was performed of new publications between 2015 and 2020 for UTIs in children. The guideline was updated accordingly with relevant new literature.

RESULTS

The occurrence of a UTI can be the first indication of anatomical abnormalities in the urinary tract, especially in patients with a febrile UTI. The basic diagnostic evaluation should include sufficient investigations to exclude urinary tract abnormalities, but should also be as minimally invasive as possible. In recent years, more risk factors have been identified to predict the presence of these anatomical anomalies, such as a non-E. Coli infection, high grade fever and ultrasound abnormalities. When these risk factors are factored into the diagnostic work-up, some invasive investigations can be omitted in a larger group of children. In addition to the treatment of active UTIs, it is also essential to prevent recurrent UTIs and consequent renal scarring. With the increase of antimicrobial resistance good antibiotic stewardship is needed. In addition, alternative preventative measures such as dietary supplements, bladder and bowel management and antibiotic prophylaxis could decrease the incidence of recurrent UTI.

CONCLUSION

This paper is a summary of the updated 2021 EAU guidelines on Pediatric Urology. It provides practical considerations and flowcharts for the management and diagnostic evaluation of UTIs in children.

Predictive score for vesicoureteral reflux in children with a first febrile urinary tract infection

OBJECTIVE

To develop a simple score for predicting vesicoureteral reflux after a first febrile urinary tract infection in children.

METHODS

A retrospective cohort study was conducted for a 12-year period (January 2008 to December 2019), including patients aged <72 months who underwent renal ultrasonography and voiding cystourethrography after a first febrile urinary tract infection. Patients with a history of antenatal hydronephrosis were excluded. The prediction model and score for vesicoureteral reflux were developed using multivariate logistic regression analysis.

RESULTS

Out of 260 patients in total (median age 4 months, 172 boys), 41 (16%) had vesicoureteral reflux. The score was based on four independent risk factors, including age >6 months (odds ratio 2.71, 95% confidence interval 1.27-5.76), presence of sepsis (odds ratio 3.44, 95% confidence interval 1.31-9.04), white blood cell count ≥15 000/mm³ (odds ratio 1.83, 95% confidence interval 0.88-3.8) and abnormal renal ultrasonography results (odds ratio 2.08, 95% confidence interval 1-4.31). A lower probability of vesicoureteral reflux (positive likelihood ratio = 0.66; P = 0.001) was found in the low-risk group (scores 0-2), whereas a higher probability of vesicoureteral reflux (positive likelihood ratio = 2.54; P = 0.001) was found in the high-risk group (scores 3-5). The predictive ability of the model was 70%.

CONCLUSIONS

The scores developed based on the patient characteristics and renal ultrasonography are useful in predicting presence of vesicoureteral reflux after a first febrile urinary tract infection in children and could guide clinicians' decisions to perform additional imaging studies.

Prediction of vesicoureteral reflux in children with febrile urinary tract infection using relative uptake and cortical defect in DMSA scan

BACKGROUND

Vesicoureteral reflux (VUR) is an important urologic anomaly that causes renal injury in children with febrile urinary tract infection (UTI). The present study aimed to evaluate the associations of abnormalities detected on technetium-99m-labeled dimercaptosuccinic acid (DMSA) scans, focusing on the association with VUR of the levels of relative decrease in kidney function and cortical defects after a first febrile UTI in children.

METHODS

All 171 children underwent ultrasonography, DMSA scan and voiding cystourethrography (VCUG). The features of ultrasound and DMSA scans were compared between patients with (n = 48) and without VUR (n = 123). The relative uptake (RU) by each kidney was derived from the absolute value of the differences between the value for RU of radionuclide in the right kidney and that in the left kidney. The extent of cortical defects (ECD) was graded according to the number of compartments that contained cortical defect in both kidneys (right upper/right lower, left upper/left lower). Receiver operating characteristic curves were constructed to examine the diagnostic value of these parameters of ultrasound and DMSA scans for predicting VUR.

RESULTS

The ratio of patients having hydronephrosis on ultrasound or cortical defects on DMSA scan did not differ significantly between VUR and non-VUR groups. However, the absolute values of the RU and the scores for ECD were significantly higher in the VUR group than in the non-VUR group. The area under the curves for these two parameters were higher than those for the presence of hydronephrosis or the presence of cortical defects or both.

CONCLUSION

Decreased relative function and increased extents of cortical defects on DMSA scan may be associated with the presence of VUR. These findings may assist pediatricians to decide whether febrile UTI children need to undergo VCUG.