Risk Factors for Recurrent Urinary Tract Infection and Renal Scarring

Genetic determinants of renal scarring in children with febrile UTI

BACKGROUND

Febrile urinary tract infections (UTIs) are among the most severe bacterial infections in infants, in which a subset of patients develops complications. Identifying infants at risk of recurrent infections or kidney damage based on clinical signs is challenging. Previous observations suggest that genetic factors influence UTI outcomes and could serve as predictors of disease severity. In this study, we conducted a nationwide survey of infant genotypes to develop a strategy for infection management based on individual genetic risk. Our aims were to identify genetic susceptibility variants for renal scarring (RS) and genetic host factors predisposing to dilating vesicoureteral reflux (VUR) and recurrent UTIs.

METHODS

To assess genetic susceptibility, we collected and analyzed DNA from blood using exome genotyping. Disease-associated genetic variants were identified through bioinformatics analysis, including allelic frequency tests and odds ratio calculations. Kidney involvement was defined using dimercaptosuccinic acid (DMSA) scintigraphy.

RESULTS

In this investigation, a cohort comprising 1087 infants presenting with their first episode of febrile UTI was included. Among this cohort, a subset of 137 infants who underwent DMSA scanning was subjected to gene association analysis. Remarkable genetic distinctions were observed between patients with RS and those exhibiting resolved kidney involvement. Notably, the genetic signature indicative of renal scarring prominently featured mitochondrial genes.

CONCLUSIONS

In this nationwide study of genetic susceptibility to RS after febrile UTIs in infancy, we identified a profile dominated by mitochondrial polymorphisms. This profile can serve as a predictor of future complications, including RS and recurrent UTIs.

Sonographic temporary nephromegaly in children during their first febrile urinary tract infection is a significant prognostic factor for recurrent infection

There are currently no available data on the relationship between sonographic temporary nephromegaly in children during their first febrile urinary tract infection (fUTI) and recurrent fUTI. For this analysis, a multicenter retrospective cohort study of 343 children who underwent renal ultrasound during their first fUTI was conducted between 2013 and 2020. Sonographic temporary nephromegaly was defined as increased renal length during the initial fUTI, followed by normal renal length after antibiotic treatment. Compared with children without sonographic temporary nephromegaly (n = 307), the duration of fever and intravenous antibiotics was significantly longer, and C-reactive protein, creatinine, and the proportion of children who had recurrent fUTI were significantly higher, in those with sonographic temporary nephromegaly (n = 36). In an additional analysis of 100 patients who received voiding cystourethrography, a logistic regression model confirmed that the odds of vesicoureteral reflux (VUR) were significantly higher in children with temporary nephromegaly or those who experienced fUTI recurrence. In nine out of 16 children with VUR who had temporary nephromegaly, the reason for receiving voiding cystourethrography was recurrent fUTI. Our results suggest that sonographic temporary nephromegaly during an initial fUTI is predictive for recurrence and VUR, and that in children with temporary nephromegaly, VUR may be detectable before fUTI recurrence.

Infant urinary tract infection in Sweden - A national study of current diagnostic procedures, imaging and treatment

BACKGROUND

Urinary tract infection (UTI) in infants is a common, potentially life-threatening bacterial infection, and must be managed carefully through the entire chain of care from diagnosis, choice of treatment, follow-up and risk stratification of future complications. This Swedish nationwide study of infant UTI was conducted to evaluate the current management of infant UTI, yield of investigations and the Swedish UTI guidelines' ability to detect abnormalities of importance in the urinary tract.

METHODS

Infants < 1 year with a first episode of UTI were included in a prospective multicenter study. Treatment and follow-up were provided by local pediatricians. Clinical and laboratory findings and imaging results were reported to the coordinating center. The current management and results were compared with a previous Swedish study.

RESULTS

One thousand three hundred six infants were included. Urine sampling was performed with clean catch technique in 93% of patients. Initial oral antibiotic treatment was used in 63%, predominantly third generation cephalosporines. Permanent kidney abnormalities were found in 10% and dilating vesicoureteral reflux (VUR) in 8%. Higher rates of male gender, non-E. coli infection and ultrasound dilatation were seen in infants < 1 month. UTI recurrences were reported in 18%.

CONCLUSIONS

Infant UTI is still generating a considerable amount of follow-up examinations. There is a significant shift towards clean catch as the main urine sampling method. Voiding cystourethrography is performed less frequently reducing the findings of low grade VUR. The incidence of renal scarring is comparable with earlier studies which suggests that the Swedish guidelines are able to identify individuals with risk for long-term complications.

Evaluating the requirement of ultrasonography for children with their first urinary tract infection

BACKGROUND

Management of urinary tract infection (UTI) in children remains important. It may be the first sign for a possible underlying congenital abnormalities for the kidney and urinary tract (CAKUT). This study examined whether performing renal and bladder ultrasonography (RBUS) only for children who have a pathogen other than E. coli during their first urinary tract infection (UTI), or who experience UTI recurrence, would result in more missed diagnoses of kidney anomalies.

METHODS

Patients aged between 2 months and 2 years who were seen in a tertiary pediatric hospital during a 2-year period and diagnosed with UTI were included. RBUS and voiding cystourethrography (VCUG) were performed according to American Academy of Pediatrics (AAP) guidelines. Afterwards, we looked back and evaluated how often we found kidney problems when we only did a RBUS on patients who had an atypical cause of their first UTI or who had multiple UTIs.

RESULTS

One hundred and seventy-eight patients who were followed up with UTI were included in this study. The isolated pathogen was E. coli in 104 cases (58.4 %) and atypical in 74 cases (41.6 %). VCUG was conducted on 40 patients, and vesicoureteral reflux (VUR) was discovered in 16 cases and ureteropelvic junction obstruction (UPJO) was discovered in 1 case. A different diagnostic approach that required the presence of an atypical pathogen at the first UTI or a fUTI recurrence to perform the RBUS would have missed just two severe kidney anomalies. It was observed that there could be a decrease of 40.4 % in RBUS and at least 20 % in VCUG.

CONCLUSIONS

A diagnostic approach that necessitates the presence of an abnormal pathogen during the initial UTI or a second UTI episode for the RBUS to be carried out would lead to fewer negative ultrasounds with minimal risk of overlooking kidney anomalies.

Long-term consequences of urinary tract infection in childhood: an electronic population-based cohort study in Welsh primary and secondary care

BACKGROUND

Childhood urinary tract infection (UTI) can cause renal scarring, and possibly hypertension, chronic kidney disease (CKD), and end-stage renal failure (ESRF). Previous studies have focused on selected populations, with severe illness or underlying risk factors. The risk for most children with UTI is unclear.

AIM

To examine the association between childhood UTI and outcomes in an unselected population of children.

DESIGN AND SETTING

A retrospective population-based cohort study using linked GP, hospital, and microbiology records in Wales, UK.

METHOD

Participants were all children born in 2005-2009, with follow-up until 31 December 2017. The exposure was microbiologically confirmed UTI before the age of 5 years. The key outcome measures were renal scarring, hypertension, CKD, and ESRF.

RESULTS

In total, 159 201 children were included; 77 524 (48.7%) were female and 7% (n = 11 099) had UTI before the age of 5 years. A total of 0.16% (n = 245) were diagnosed with renal scarring by the age of 7 years. Odds of renal scarring were higher in children by age 7 years with UTI (1.24%; adjusted odds ratio 4.60 [95% confidence interval [CI] = 3.33 to 6.35]). Mean follow-up was 9.53 years. Adjusted hazard ratios were: 1.44 (95% CI = 0.84 to 2.46) for hypertension; 1.67 (95% CI = 0.85 to 3.31) for CKD; and 1.16 (95% CI = 0.56 to 2.37) for ESRF.

CONCLUSION

The prevalence of renal scarring in an unselected population of children with UTI is low. Without underlying risk factors, UTI is not associated with CKD, hypertension, or ESRF by the age of 10 years. Further research with systematic scanning of children's kidneys, including those with less severe UTI and without UTI, is needed to increase the certainty of these results, as most children are not scanned. Longer follow-up is needed to establish if UTI, without additional risk factors, is associated with hypertension, CKD, or ESRF later in life.

Association Between Antibiotic Duration and Recurrence of Urinary Tract Infection in the Neonatal Critical Care Unit

OBJECTIVES

Urinary tract infection (UTI) is the most common bacterial infection in infants. Current practice guidelines suggest a treatment duration of 7 to 14 days. Suboptimal therapy may increase the risk for recurrent UTIs leading to renal scarring and possibly chronic kidney disease. The primary objective is to evaluate the duration of therapy for UTIs and its association with the incidence of recurrent UTIs in a neonatal intensive care unit (NICU). The secondary objectives are to identify the risk factors and the most common organisms for recurrent UTIs.

METHODS

Patients were identified via the diagnosis codes for UTIs and were included if admitted to the NICU and if they received antibiotics prior to hospital discharge. Patients were divided into 2 groups: antibiotic treatment for 7 days or fewer and antibiotic treatment for greater than 7 days.

RESULTS

Eighty-six infants were included in the study. Twenty-six patients received antibiotics for 7 days or fewer, and 60 for more than 7 days. In the study, the median birth weight was 977 g and the median gestational age was 27.6 weeks. There was no significant difference in the rate of recurrent UTIs between the 2 groups (p = 0.66). However, in the subgroup analysis, the incidence was higher for patients receiving antibiotic therapy for fewer than 7 days versus 7 days (p = 0.03).

CONCLUSION

There was no difference in recurrence of UTI between treatment groups (≤7 days versus >7 days), and recurrence was seen in a higher percentage of patients with a urinary tract anomaly.

Review of Urinary Tract Infections and Pyelonephritis

Urinary tract infections (UTIs) are serious bacterial infections affecting children of all ages. An understanding of the methods of urine collection is important to prevent the contamination of urine specimens and to interpret results. The diagnosis of a UTI requires appropriate interpretation of both urinalysis and urine culture results because testing must indicate evidence of inflammation and the presence of bacteria. Rapid treatment of UTIs is imperative to prevent acute decompensation and systemic illness. Empiric antibiotics should be narrowed as soon as possible to tailor antibiotic treatment and limit antibiotic overuse. Imaging with a renal ultrasound scan is recommended for all infants with first febrile UTIs rather than a voiding cystourethrogram. An additional goal of UTI treatment is to prevent renal scarring, which can lead to lifelong health consequences. Children with anatomic abnormalities of the urinary tract and those who have recurrent UTIs are at increased risk of renal scarring. [Pediatr Ann. 2024;53(6):e217-e222.].

Lactobacillus rhamnosus PL1 and Lactobacillus plantarum PM1 versus Placebo as Prophylaxis for Recurrence of Urinary Tract Infections in Children

Urinary tract infections (UTIs) rank among the most prevalent bacterial infections in children. Probiotics appear to reduce the risk of recurrence of UTIs. This study aimed to evaluate whether probiotics containing Lactobacillus rhamnosus PL1 and Lactobacillus plantarum PM1 therapy prevent UTIs in the pediatric population compared to a placebo. A superiority, double-blind, randomized, controlled trial was conducted. In total, 54 children aged 3-18 years with recurrent UTIs or ≥one acute pyelonephritis and ≥one risk factor of recurrence of UTIs were randomly assigned (27 patients in each arm) to a 90-day probiotic or placebo arm. The age, sex, diagnosis, renal function, risk factors, and etiology of UTIs did not vary between the groups. During the intervention, 26% of children taking the probiotic had episodes of UTI, and it was not significantly less than in the placebo group. The number of UTI episodes during the intervention and the follow-up period decreased significantly in both groups, but the difference between them was insignificant. We observed a decrease in UTIs during the study of almost 50% in the probiotic group compared to the placebo group. Probiotics can be used as natural, safe prophylaxis for children with risk factors for UTIs in whom antibiotic prevention is not indicated.

Prevalence of Enterococcal Urinary Tract Infections With Positive Nitrites in Urinalysis in Pediatric Patients With High-Risk for Enterococcal Infections

Enterococcus is a relatively uncommon pathogen that causes urinary tract infections (UTIs) in healthy children. Most enterococcal infections occur in patients with risk factors such as anatomical or functional urinary tract anomalies, also known as CAKUT (congenital anomalies of kidney and urinary tract). Children who are suspected of having UTIs and who have certain risk factors are often treated specifically for enterococcal infection as part of their empiric regimen. Our primary objective was to determine the prevalence of enterococcal UTIs among high-risk children, and specifically among those with positive nitrite tests, with the goal of avoiding treatment with specific anti-enterococcal agents. This retrospective study included all the episodes of UTI treated at a tertiary pediatric center during 2010 to 2018. The data collected from medical records included nephrological and urological risk factors, nitrite status, and isolated pathogens. Of 931 episodes of UTI, 467 (50%) were considered high-risk. In all, 24 of the latter had Enterococcus as a single pathogen; 23 (96%) of these occurred in patients with negative nitrites in the first urine dipstick taken. The sole patient with high-risk factors, a positive nitrite test and coexisting enterococcal UTI had a history of previous enterococcal UTIs. In pediatric patients with nephrological and urological risk factors, who have positive nitrites in urinalysis, the risk for enterococcal UTI appears substantially low. Therefore, in this context, specific anti-enterococcal empirical antibiotic therapy may be unnecessary.

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.

Paediatricians' perspectives in treating lower urinary tract symptoms: a qualitative exploratory needs assessment study

BACKGROUND

Paediatric lower urinary tract symptoms (LUTS) are common experiences among school-aged children, with prevalence rates reaching as high as 20%. Paediatricians are often first-line stakeholders in providing treatment for these bothersome symptoms, yet there is no formal resource to support them with the treatment of LUTS. Evaluating paediatricians' experiences is an important step in informing health promotion efforts to improve health outcomes in children. This study aims to explore paediatricians' knowledge, beliefs, practice patterns, and perceived barriers and facilitators in providing LUTS care.

METHODS

In this qualitative study, we conducted semistructured focus groups of paediatricians within California. Focus groups were conducted via Zoom, and participants were enrolled until thematic saturation was reached. Participants were asked about their current practices, knowledge and beliefs, barriers and facilitators to care, training and education, and responsibility for behaviour and action. Thematic analysis was performed using deductive and inductive approaches; themes were mapped through an iterative, team-based process.

RESULTS

15 paediatricians, aged 30-69 years, with 13 (86.7%) women, were interviewed. Most (11, 73.3%) practised in general outpatient settings. Interviewed paediatricians recognised paediatric LUTS as a common problem that can significantly impact children's well-being. In practice, paediatricians did not actively screen for LUTS beyond the potty-training milestone due to short visit duration and competing healthcare demands. Lack of guidelines, parental mistrust and inadequate clinical education were barriers identified by paediatricians.

CONCLUSIONS

Paediatricians expressed a willingness to help patients but indicated several limitations to providing adequate LUTS care. Future professional development work can emphasise guideline development, early screening strategies to support timely intervention and better education for clinicians.

Pattern of urinary tract infection in children with vesicoureteric reflux: Does breastfeeding reduce the occurrence of urinary tract infection?

Introduction

The protective factors against urinary tract infections (UTIs) in the setting of vesicoureteric reflux (VUR) remain poorly defined. Breastfeeding was suggested as a protective factor against UTI, but its role remains undetermined in this highly susceptible population.

Objectives

The objective of the study was to identify the pattern and risk factors of UTI and investigate the effect of breastfeeding on UTI occurrence in VUR children.

Materials and Methods

This was a mixed-method design, whereby the first part was a cross-sectional study that included children who were diagnosed with VUR and were assessed for their UTI pattern. The second part was a case-control study, which involved contacting the mothers of the children enrolled and questioning them about their breastfeeding pattern, and UTI development was assessed.

Results

Our study included 62 children with a median age of 4.4 (interquartile range = 21) months at diagnosis. Of those, 37 (60%) were male and 25 (40%) were female. Most UTIs occurred in the first 3 months of life, and the first episodes were more frequent in males. Constipation was significantly associated with the occurrence of UTI (relative risk [RR] =1.750 [95% confidence interval (CI): 1.231-2.489], P = 0.003). Children with breakthrough UTIs were more likely to have been breastfed for <9 months (odds ratio [OR] = 4.091 [95% CI: 1.287-13.002], P = 0.015) and to have been exclusively breastfed for <2 months (OR = 4.600 [95% CI: 1.337-15.823], P = 0.012).

Conclusion

Children with VUR are more susceptible to UTIs in their 1st year of life. Constipation is a major risk factor for UTI occurrence in VUR children and should be aggressively managed. Breastfeeding for longer durations showed promising protective features against breakthrough UTIs.

Longitudinal follow-up of bladder function in children who participated in the Swedish Reflux Trial

BACKGROUND

Several publications have reported the coexistence of vesicoureteral reflux (VUR) and bladder dysfunction in children. Whether this dysfunction remains in the longer term is not yet known.

OBJECTIVE

This study revisited children who participated in the Swedish Reflux Trial (SRT) with the primary aim of evaluating whether bladder and bowel dysfunction (BBD) in these patients persisted until adolescence. The secondary aim was to evaluate two BBD subgroups, and relations to recurrent urinary tract infections (UTI).

STUDY DESIGN

Of the 161 eligible children at SRT study-end, 73 children participated. Their bladder function was evaluated longitudinally using a validated BBD questionnaire with symptom score (cut-off ≥7) and uroflowmetry, at five (T2) and ten years (T3) after study-end. T1 was the SRT study-end. Besides BBD, the sub-diagnoses overactive bladder (OAB) and dysfunctional voiding symptoms (DVS) were calculated from symptom scores.

RESULTS

BBD was diagnosed in 37% of children at mean age 3.7 years, which decreased with age to 23% of adolescents (mean age 15.7). DVS and OAB subgroups were equally common at T1, but only DVS was identified at the last follow-up (T3) (p = 0.0008). Recurrent UTIs were seen in 17% at T3 and were more common in patients with BBD (p = 0.038). The gender distribution of BBD also changed, from being equally common at the end of the SRT to affecting mainly adolescent girls at the last follow-up (p = 0.022). Information was available regarding VUR status after repeat VCUGs during follow-up in 22 patients, 12 of them after endoscopic treatment. An improvement in VUR grade was found in the 22, but during follow-up numbers with BBD or UTI did not differ between treated and non-treated groups.

DISCUSSION

The prevalence of BBD decreased from 37% at 3-4 years of age to 23% in adolescence, when it was almost exclusively seen in girls. BBD and the subgroup DVS were associated with UTI. Even if epidemiological studies have established a predisposition to bladder symptoms and UTI in girls, little is known about bladder function in adolescents with a history of VUR during the first years of life. One limitation of the study was the number of patients participating. Also, the number of patients with kidney damage was more common in the cohort.

CONCLUSION

In this longitudinal follow-up of BBD in children with VUR, the number of children with BBD decreased with age. In adolescence, both BBD and recurrent UTIs mainly affected girls.

Evaluation of the results of urodynamic studies in patients with vesicoureteral reflux

BACKGROUND

To investigate urodynamic abnormalities associated with vesicoureteral reflux (VUR) in toilet-trained children.

METHODS

The data of 157 children who were diagnosed with vesicoureteral reflux and referred to our hospital between 2013 and 2022 were retrospectively examined. The urodynamic parameters were analyzed and correlated with age, gender, lower urinary tract symptoms (LUTS), reflux severity, and laterality.

RESULTS

Overall, 131 (83.4%) patients had abnormal urodynamic findings with a male-to-female ratio of 1:1.4. The most common pathological finding was detrusor overactivity (DO), identified in 101 (64.3%) patients, followed by dysfunctional voiding (DV) in 74 (50.3%) patients. Children with VUR grades II and III exhibited a greater percentage of abnormal urodynamic findings than children with grades IV and V. The prevalence of DO was higher in children younger than 10 years old with unilateral and lower-grade VURs. DV was more frequent in children older than 10 years, with bilateral VUR, and higher grade VUR. The prevalence of LUTS, bowel and bladder dysfunction (BBD), and urinary tract infection (UTI) was higher among children with abnormal urodynamic findings.

CONCLUSIONS

Children with VUR have a high incidence of urodynamic disorders. Urodynamic dysfunction may contribute to the pathogenesis of VUR, especially in mild cases.

Risk factors for new renal scarring in children with vesicoureteral reflux receiving continuous antibiotic prophylaxis

To investigate the risk factors for new renal scarring (NRS) in children with vesicoureteral reflux (VUR) receiving continuous antibiotic prophylaxis (CAP). This was a single-center cohort study. The clinical data of 140 children with grade I-V VUR receiving CAP were analyzed. In this study, exposure variables were sex, younger age at the initial diagnosis of UTI ≤ 12 months, the occurrence of breakthrough urinary tract infection (BT-UTI), high-grade VUR, bilateral VUR, etiology, presence of renal scarring at the initial diagnosis and ultrasound abnormalities. The outcome was NRS. A total of 140 children were included in the risk factor analysis of NRS, 73 of whom experienced NRS, an incidence rate of 52.14%. Multivariate Cox regression suggested that the presence of renal function impairment after the initial diagnosis of UTI (OR 3.411, 95% CI 1.5751-6.646) and the occurrence of BT-UTI while receiving CAP (OR 1.995, 95% CI 1.089-2.958) were independent risk factors for NRS. Multivariate Cox regression showed that high-grade VUR had no significant effects on NRS (OR 0.940, 95% CI 0.462-1.912, P = 0.864). No significant difference was identified in multivariate Cox regression analysis in the IV-V group (vs I-III group) (OR 0.960, 95% CI 0.565-1.633, P = 0.960). Renal function impairment after the initial diagnosis of UTI and the occurrence of BT-UTI while receiving CAP were independent risk factors for NRS. Neither univariate analysis nor multivariate analysis found a correlation between VUR grade and NRS.

A study on the risk stratification for patients within 24 hours of admission for risk of hospital-acquired urinary tract infection using Bayesian network models

Early identification of patients at risk of hospital-acquired urinary tract infections (HA-UTI) enables the initiation of timely targeted preventive and therapeutic strategies. Machine learning (ML) models have shown great potential for this purpose. However, existing ML models in infection control have demonstrated poor ability to support explainability, which challenges the interpretation of the result in clinical practice, limiting the adaption of the ML models into a daily clinical routine. In this study, we developed Bayesian Network (BN) models to enable explainable assessment within 24 h of admission for risk of HA-UTI. Our dataset contained 138,250 unique hospital admissions. We included data on admission details, demographics, lifestyle factors, comorbidities, vital parameters, laboratory results, and urinary catheter. Models developed from a reduced set of five features were characterized by transparency compared to models developed from a full set of 50 features. The expert-based clinical BN model over the reduced feature space showed the highest performance (area under the curve = 0.746) compared to the naïve- and tree-augmented-naïve BN models. Moreover, models developed from expert-based knowledge were characterized by enhanced explainability.

Effectiveness of various treatment modalities in children with vesicoureteral reflux grades II-IV: a systematic review and network meta-analysis

BACKGROUND

Vesicoureteral reflux (VUR) is one of the most common risk factors of urinary tract infection (UTI) among children. Various treatment modalities including antibiotic prophylaxis, surgical or endoscopic corrections and conservative treatment were used depending on the severity of VUR. The aim of this study is to compare the effectiveness of these treatment modalities in children with VUR grades II-IV by conducting a systematic review and network meta-analysis.

METHODS

A systematic search from different databases was performed from their earliest records to December 2022 without any language restriction. Only randomised controlled trials were included in this study. Effectiveness of treatment modalities was mainly compared by UTI. Other outcomes for renal scarring and resolution by renal units were also measured between treatments.

RESULTS

A total of 11 studies with 1447 children were included in this study. While comparing with antibiotic prophylaxis in network meta-analysis for UTI recurrence, surgical treatment probably lowers the rate of UTI recurrence (Log OR -0.26, 95% CI -0.54 to 0.02, high quality). However, endoscopic treatment (Log OR 0.2, 95% CI -1.41 to 1.81, high quality) and conservative treatment (Log OR 0.15, 95% CI -0.45 to 0.75, high quality) revealed probably inferior to antibiotic treatment.

CONCLUSION

Both pairwise and network meta-analytic results probably showed no difference between the treatments in terms of their impact on UTI recurrence, progression of previous renal scars, or formation of new renal scars in children with VUR grades II-IV. These findings may offer a better understanding of each treatment and evidence-based suggestions for the choice of treatment, which should be individualised and based on the patient's risk factors.

Uropathogen and host responses in pyelonephritis

Urinary tract infections (UTIs) are among the most common bacterial infections seen in clinical practice. The ascent of UTI-causing pathogens to the kidneys results in pyelonephritis, which can trigger kidney injury, scarring and ultimately impair kidney function. Despite sizable efforts to understand how infections develop or are cleared in the bladder, our appreciation of the mechanisms by which infections develop, progress or are eradicated in the kidney is limited. The identification of virulence factors that are produced by uropathogenic Escherichia coli to promote pyelonephritis have begun to fill this knowledge gap, as have insights into the mechanisms by which kidney tubular epithelial cells oppose uropathogenic E. coli infection to prevent or eradicate UTIs. Emerging data also illustrate how specific cellular immune responses eradicate infection whereas other immune cell populations promote kidney injury. Insights into the mechanisms by which uropathogenic E. coli circumvent host immune defences or antibiotic therapy to cause pyelonephritis is paramount to the development of new prevention and treatment strategies to mitigate pyelonephritis and its associated complications.

Urinary Tract Infections: Renal Intercalated Cells Protect against Pathogens

Urinary tract infections affect more than 1 in 2 women during their lifetime. Among these, more than 10% of patients carry antibiotic-resistant bacterial strains, highlighting the urgent need to identify alternative treatments. While innate defense mechanisms are well-characterized in the lower urinary tract, it is becoming evident that the collecting duct (CD), the first renal segment encountered by invading uropathogenic bacteria, also contributes to bacterial clearance. However, the role of this segment is beginning to be understood. This review summarizes the current knowledge on CD intercalated cells in urinary tract bacterial clearance. Understanding the innate protective role of the uroepithelium and of the CD offers new opportunities for alternative therapeutic strategies.

Urogenital urobiome of healthy children does not differ from that of children with bladder and bowel dysfunction

INTRODUCTION

The pediatric urinary microbiome (urobiome) has been studied in the context of healthy children and children with genitourinary pathologies including neuropathic bladder, urinary tract infection (UTI) and nephrolithiasis. Little is known about the urobiome of children with bladder and bowel dysfunction (BBD), a condition that is an established risk factor of UTI. We hypothesized that the symptoms of a child with BBD may be related to urobiome composition.

OBJECTIVE

To evaluate the urogenital urobiome's role in BBD, we compared the urogenital urobiomes of children with and without BBD.

STUDY DESIGN

We performed a prospective case-control pilot study at a single large, academic children's hospital. Cases included toilet trained prepubertal females over 2 years of age with BBD established through a validated scoring system and controls included asymptomatic, presumably healthy, children. Children were excluded if they had symptoms or lab work consistent with a concurrent UTI or antibiotic course for any reason within the prior 14 days. We performed 16 S ribosomal RNA gene sequencing and expanded quantitative urine culture on clean catch urine samples. To compare within sample (alpha) diversity, we used the Kruskal-Wallis test. To compare between sample (beta) diversity, we calculated the Bray-Curtis distance and performed the PERMANOVA test.

RESULTS

Data from 25 children with BBD and 8 asymptomatic controls were analyzed. The demographic and clinical characteristics of the two comparison groups were similar, though a higher proportion of Black children were included in the asymptomatic control group. Neither alpha diversity nor beta diversity was significantly different between the two groups. The core microbiome of the BBD group included all the genera in the core urogenital urobiome of the controls, plus additional genera associated with opportunistic infection and/or UTI, including Escherichia, Campylobacter and Streptococcus.

DISCUSSION

The results of both the 16 S sequencing and expanded quantitative urine culture in this small study suggest that the urogenital urobiomes of children with BBD do not differ significantly from those of asymptomatic children. However, the core urogenital urobiome of children with BBD included genera associated with opportunistic infection and/or UTI. This study was limited by the sample collection method ("clean catch" midstream voided urine samples, which introduce the possibility of vulvovaginal contamination), small sample size, and unequal balance of patient characteristics between the two study groups.

CONCLUSION

The urogenital urobiomes of children with and without BBD do not appear to significantly differ. Larger studies are needed to confirm these findings.

Alternative Antimicrobial Irrigation Strategies for the Treatment of Infections in Children: A Review of the Existing Literature

As a synergistic treatment approach with systemic antimicrobial therapy or a systemic antibiotic-sparing strategy, the local administration of antimicrobial agents has been proposed as an alternative route for complicated infections. With the rationale of concentrating the active principle in the desired target site, avoiding potentially toxic systemic levels and bypassing anatomical and physiological barriers, local irrigation or infusion of antibiotics may effectively shorten the antimicrobial therapy course and reduce both infection-related and systemic therapy-related complications. Although evidence from the adult population supports its use in selected patients with an acceptable safety profile, data specifically focused on the pediatric population are limited. To provide a rapid and easily accessible tool for clinical practice, we synthesized the most relevant evidence on the use of local antimicrobial agents in common severe infections in children: meningitis, mediastinitis, pleural infections, recurrent urinary infections, and peritonitis. A literature search was performed using predefined combined keywords through an electronic research database (PubMed). Described molecules, dosages, routes, treated age groups, and related efficacy have been summarized for prompt application to clinical practice. It should, however, be noted that the evidence for the pediatric population remains limited, and the local administration of several molecules remains off-label. A careful multidisciplinary and patient-tailored evaluation, as well as a rational use of available guidelines, should always be the basis of clinical decision making in settings where local administration of antibiotics may be considered.

Urinary Tract Infections Caused by Uropathogenic Escherichia coli: Mechanisms of Infection and Treatment Options

Urinary tract infections (UTIs) are common bacterial infections that represent a severe public health problem. They are often caused by Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumonia), Proteus mirabilis (P. mirabilis), Enterococcus faecalis (E. faecalis), and Staphylococcus saprophyticus (S. saprophyticus). Among these, uropathogenic E. coli (UPEC) are the most common causative agent in both uncomplicated and complicated UTIs. The adaptive evolution of UPEC has been observed in several ways, including changes in colonization, attachment, invasion, and intracellular replication to invade the urothelium and survive intracellularly. While antibiotic therapy has historically been very successful in controlling UTIs, high recurrence rates and increasing antimicrobial resistance among uropathogens threaten to greatly reduce the efficacy of these treatments. Furthermore, the gradual global emergence of multidrug-resistant UPEC has highlighted the need to further explore its pathogenesis and seek alternative therapeutic and preventative strategies. Therefore, a thorough understanding of the clinical status and pathogenesis of UTIs and the advantages and disadvantages of antibiotics as a conventional treatment option could spark a surge in the search for alternative treatment options, especially vaccines and medicinal plants. Such options targeting multiple pathogenic mechanisms of UPEC are expected to be a focus of UTI management in the future to help combat antibiotic resistance.

Quality indicators for appropriate antibiotic prescribing in urinary tract infections in children

BACKGROUND

The aim of this study was to define a set of urinary tract infections (UTIs)-specific quality indicators for appropriate prescribing in children and evaluate clinical practices in a district general hospital in Greece.

METHODS

The UTIs-specific quality indicators were informed by a review of the existing literature. Quality indicators were selected to describe the overall antibiotics use, prescribing patterns and UTIs clinical management regarding treatment and prophylaxis in a cohort of children admitted with a UTI. Microbiological, clinical and prescribing data about dosing, duration and route of administration were collected from the patients' electronic health records.

RESULTS

Twelve quality indicators were adapted or developed for prescribing in childhood UTIs. A broad variety of antibiotics were prescribed for UTIs, with a drug utilization (DU) 90% rate of 6 and 9 different antibiotics for febrile and afebrile UTIs, respectively. Despite the low incidence of multi-drug resistant UTIs in the study period (9/261, 3.4%), broad-spectrum antibiotics were prescribed in 33.5% (164/490) of prescriptions. A total of 62.8% (164/261) of patients were started on empiric combined therapies, while opportunities to de-escalate were missed in 37.8% (62/164) of them. One quarter (67/261, 25.7%) of patients did not fulfil the criteria for receiving treatment, while nearly half of those prescribed prophylaxis (82/175, 46.9%) could have avoided having a prophylaxis prescription.

CONCLUSIONS

Our study identified substantial gaps for improvement in antimicrobial prescribing for UTIs in children. The application of the proposed quality indicators could help to limit unnecessary antibiotics use in children with UTI.

Safety and Efficacy of Ceftolozane/Tazobactam Versus Meropenem in Neonates and Children With Complicated Urinary Tract Infection, Including Pyelonephritis: A Phase 2, Randomized Clinical Trial

BACKGROUND

Ceftolozane/tazobactam, a cephalosporin-β-lactamase inhibitor combination, active against multidrug-resistant Gram-negative pathogens, is approved for treatment of adults with complicated urinary tract infections (cUTI). Safety and efficacy of ceftolozane/tazobactam in pediatric participants with cUTI, including pyelonephritis, were assessed.

METHODS

This phase 2 study (NCT03230838) compared ceftolozane/tazobactam with meropenem for treatment of cUTI in participants from birth to <18 years of age. The primary objective was safety and tolerability. Key secondary end points included clinical cure and per-participant microbiologic response rates at end of treatment (EOT) and test of cure (TOC) visits.

RESULTS

The microbiologic modified intent-to-treat (mMITT) population included 95 participants (ceftolozane/tazobactam, n = 71; meropenem, n = 24). The most common diagnosis and pathogen were pyelonephritis (ceftolozane/tazobactam, 84.5%; meropenem, 79.2%) and Escherichia coli (ceftolozane/tazobactam, 74.6%; meropenem, 87.5%); 5.7% (ceftolozane/tazobactam) and 4.8% (meropenem) of E. coli isolates were extended-spectrum β-lactamase-producers. Rates of adverse events were similar between treatment groups (any: ceftolozane/tazobactam, 59.0% vs. meropenem, 60.6%; drug-related: ceftolozane/tazobactam, 14.0% vs. meropenem, 15.2%; serious: ceftolozane/tazobactam, 3.0% vs. meropenem, 6.1%). Rates of clinical cure for ceftolozane/tazobactam and meropenem at EOT were 94.4% and 100% and at TOC were 88.7% and 95.8%, respectively. Rates of microbiologic eradication for ceftolozane/tazobactam and meropenem at EOT were 93.0% and 95.8%, and at TOC were 84.5% and 87.5%, respectively.

CONCLUSIONS

Ceftolozane/tazobactam had a favorable safety profile in pediatric participants with cUTI; rates of clinical cure and microbiologic eradication were high and similar to meropenem. Ceftolozane/tazobactam is a safe and effective new treatment option for children with cUTI, especially due to antibacterial-resistant Gram-negative pathogens.

Trends in hospitalization for urinary tract infection in the paediatric age group in the 2000-2015 period in Spain

OBJECTIVE

To analyse the trends in hospital admissions related to urinary tract infection among children aged 0-14 years in Spain in the 2000-2015 period.

METHODS

We conducted a retrospective observational study using the minimum basic hospital discharge dataset system of Spain, which applies the International Classification of Diseases, version 9 (ICD-9) coding system. We included every hospitalisation due to cystitis, pyelonephritis and unspecified UTI among children aged less than 15 years. We collected data on patient sex and age, type of discharge, main diagnosis, comorbidities, length of stay and overall cost. We calculated crude hospitalization rates per 1000 inhabitants aged less than 15 years and performed a joinpoint regression analysis to identify temporal trends.

RESULTS

In the 2000-2015 period, there were 124 696 hospitalizations in children under 15 years. Of these patients, 72.97% were aged 0-1 year and 60.12% had a diagnosis of unspecified UTI, 39.27% of pyelonephritis, and 0.52% of cystitis. The crude rate of hospitalization due to UTI ranged from 1.24 in year 2000 to 0.98 in 2015. The rate of hospitalization was higher in female versus male patients. The joinpoint analysis found a decreasing trend in the rate of hospitalization due to UTI, with an average annual percent change (AAPC) of -1.5% (95% confidence interval [CI], -2.4 a -0.6). The largest decreases occurred in female patients (AAPC, -1.8; 95% CI, -2.5 a -1.0) and children aged 7-10 years (AAPC - 5.9; 95% CI, -6.7 a -5.2).

CONCLUSIONS

The rate of hospitalization related to UTI in Spain in patients aged up to 14 years decreased during the 2000-2015 period. The highest hospitalization rates occurred in female patients and in the 0-to-1 year age group.

Functional constipation as a risk factor for pyelonephritis and recurrent urinary tract infection in children

AIM

Acute pyelonephritis is one of the most common bacterial infections in childhood. This potentially serious condition can lead to renal scarring, loss of kidney function and hypertension. The aim of this study was to identify risk factors associated with pyelonephritis in children without kidney or urinary tract abnormalities.

METHODS

Medical records of children aged 4-18 diagnosed with 1st time pyelonephritis from 2016 to 2021 were retrospectively analysed. Children with abnormal kidney ultrasound were excluded. In addition to demographic data, information on bladder and bowel function was extracted together with habits of fluid intake.

RESULTS

A total of 105 patients were diagnosed with 1st time pyelonephritis. Of these, 47% were diagnosed with constipation according to the Rome IV criteria within a mean follow-up period of 167 days after their pyelonephritis, which is markedly higher than the estimated prevalence of constipation in the background population. Constipation was positively associated with recurrent urinary tract infection (p = 0.01).

CONCLUSION

Constipation is associated with pyelonephritis and recurrent urinary tract infection in children (primarily girls) 4-18 years of age without evident kidney or urinary tract abnormalities. We recommend systematic evaluation of bowel and bladder function after 1st time pyelonephritis in all children >4 years.

How the 99mTc-DMSA scintigraphy findings are reflected in the adopted treatment of primary vesicoureteral reflux: One centre experience

BACKGROUND

Renal changes may have long-term sequalae and prevention is a main goal of management of primary vesicoureteral reflux (VUR).

AIM

This study aims to reveal how much ^99mTc-DMSA scintigraphy findings are reflected in the adopted surgical or non-surgical treatment in children with diagnosed primary VUR and to give the clinicians information regarding their final therapeutic decision.

PATIENTS AND METHODS

A total 207 children with primary VUR who underwent non-acute ^99mTc-DMSA scan were retrospectively evaluated. The presence of renal changes, their grading, differential function asymmetry (<45%) and grade of VUR were compared with subsequent choice of therapy.

RESULTS

Altogether 92 (44%) children had asymmetric differential function, 122 (59%) showed presence of renal changes, 79 (38%) had high-grade VUR (IV-V). Patients with renal changes had lower differential function (41%vs.48%) and higher grade of VUR. The incidence of high-grade changes (G3+G4B) afflicting more than one third of the kidney was significantly different between grade I-II, III and IV-V VUR (9%, 27%, 48%, respectively). Renal changes were detected in 76% of surgically and 48% of non-surgically treated patients, high-grade ^99mTc-DMSA changes in 69% and 31%, respectively. In children with no scars/dysplasia (G0+G4A), non-surgical treatment prevailed in 77%. The independent predictors for surgical intervention were presence of renal changes and higher grade of VUR, but not functional asymmetry.

DISCUSSION

Over the last 20 years, there has been a shift toward more non-surgical management of VUR. The long-term outcome of this approach should be thoroughly studied. This is the first study analysing renal status in VUR patients using ^99mTc-DMSA scan and its grading regarding the adopted treatment. Renal changes in almost half of non-surgically treated children with VUR should be an indicator for earlier diagnosis and effective treatment of acute pyelonephritis and VUR. We recommend distinguishing grade III VUR, as a moderate-grade VUR, because it is linked to higher incidence of high-grade ^99mTc-DMSA changes (G3+G4B); our findings of 65% of grade III VURs treated non-surgically should be cautionary. Grade III VUR does not mean a low-risk condition and should alert the clinician to evaluate the extent of renal changes and unmask high-risk cases.

CONCLUSIONS

Our data strengthens the need to investigate the extent of renal changes in VUR patients regarding treatment decision. Performing ^99mTc-DMSA scan individualizes the treatment of VUR patients; its grading can distinguish grade III-VUR as a separate risk entity because it differs significantly in terms of incidence of high-grade renal changes and chosen therapy.

The clinical implications of bacterial pathogenesis and mucosal immunity in chronic urinary tract infection

Urinary tract infections (UTIs) exert a significant health and economic cost globally. Approximately one in four people with a previous history of UTI continue to develop recurrent or chronic infections. Research on UTI has primarily concentrated on pathogen behavior, with the focus gradually shifting to encompass the host immune response. However, these are centered on mouse models of Escherichia coli infection, which may not fully recapitulate the infective etiology and immune responses seen in humans. The emerging field of the urobiome also inadvertently confounds the discrimination of true UTI-causing pathogens from commensals. This review aims to present a novel perspective on chronic UTI by linking microbiology with immunology, which is commonly divergent in this field of research. It also describes the challenges in understanding chronic UTI pathogenesis and the human bladder immune response, largely conjectured from murine studies. Lastly, it outlines the shortcomings of current diagnostic methods in identifying individuals with chronic UTI and consequently treating them, potentially aggravating their disease due to mismanagement of prior episodes. This discourse highlights the need to consider these knowledge gaps and encourages more relevant studies of UTIs in humans.

Epidemiology and Risk Factors of UTIs in Children-A Single-Center Observation

Urinary tract infections (UTIs) are one of childhood’s most common bacterial infections. The study aimed to determine the clinical symptoms, laboratory tests, risk factors, and etiology of different UTIs in children admitted to pediatric hospitals for three years. Methods: Patients with positive urine cultures diagnosed with acute pyelonephritis (APN) or cystitis (CYS) were analyzed for clinical symptoms, laboratory tests, risk factors, and etiology, depending on their age and sex. Results: We studied 948 children with UTIs (531 girls and 417 boys), with a median age of 12 (IQR 5−48 months). A total of 789 children had clinical symptoms; the main symptom was fever (63.4% of patients). Specific symptoms of UTIs were presented only in 16.3% of patients. Children with APN had shown significantly more frequent loss of appetite, vomiting, lethargy, seizures, and less frequent dysuria and haematuria than children with CYS. We found significantly higher median WBC, CRP, and leukocyturia in children with APN than with CYS. The risk factors of UTIs were presented in 46.6% of patients, of which 35.6% were children with APN and 61.7% with CYS. The main risk factor was CAKUT, more frequently diagnosed in children with CYS than APN, mainly in children <2 years. The most commonly isolated bacteria were Escherichia coli (74%). There was a higher percentage of urine samples with E. coli in girls than in boys. Other bacteria found were Klebsiella species, Pseudomonas aeruginosa, Proteus mirabilis, and Enterococcus species. Conclusions: Patients with APN were younger and had higher inflammatory markers. Often, fever is the only symptom of UTI in children, and other clinical signs are usually non-specific. The most common UTI etiology is E. coli, regardless of the clinical presentation and risk factors.

Incidence and Causative Organisms of Bacteriuria in Children With Cancer: A 9-Year Experience in a Tertiary Pediatric Center

Although infection is common in patients with cancer, the distribution of causative agents and the proportion of resistant bacteria in patients with urinary tract infection remain unknown. The aim of this study was to describe the incidence, the causative agents, and the proportion of antimicrobial resistance in bacteria cultured from urine of hospitalized children with cancer. A single-center retrospective chart review of patients with cancer admitted between 2012 and 2020 was performed to identify patients with positive urine culture. Overall, 61 (0.9%) of 7107 patients were identified to have positive urine cultures. Among them, 25 patients (41%) had symptomatic bacteriuria. The most common pathogenic bacterium among all patients was Escherichia coli ( E. coli ) (n=15, 25%), followed by Enterococcus sp. (n=14, 23%), Klebsiella sp. (n=12, 20%), and Pseudomonas aeruginosa ( P. aeruginosa ) (n=12, 20%). Extended spectrum β-lactamases-producing E. coli and Extended spectrum β-lactamases-producing Klebsiella pneumoniae were detected in 1 patient (2%) and 4 patients (7%), respectively. No multidrug-resistant P. aeruginosa and vancomycin-resistant Enterococcus were detected. The incidence of bacteriuria was found to be low in children with cancer. The distribution of causative agents of bacteriuria in children with solid tumors and hematologic diseases may be different from that in previously healthy children.

Urinary Tract Infection in Children

Symptoms of urinary tract infection (UTI) in young children are nonspecific and urine sampling is challenging. A safe and rapid diagnosis of UTI can be achieved with new biomarkers and culture of clean-catch urine, reserving catheterization or suprapubic aspiration for severely ill infants. Most guidelines recommend ultrasound assessment and use of risk factors to direct further management of children at risk of kidney deterioration. The increasing knowledge of the innate immune system will add new predictors and treatment strategies to the management of UTI in children. Long-term outcome is good for the majority, but individuals with severe scarring can develop hypertension and decline in kidney function.

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.

Meta-analysis of the Risk Factors for Urinary Tract Infection in Children

CONTEXT

The incidence of urinary tract infection (UTI) varies with age, but there is limited evidence on the role of other risk factors.

OBJECTIVE

The aim of this meta-analysis was to investigate the risk factors for UTIs in children.

DATA SOURCES

PubMed from 1966 to May 2019.

STUDY SELECTION

All studies assessing at least 1 possible risk factor for occurrence or recurrence of UTI with a clear definition of symptomatic UTI in children were eligible. We excluded studies with UTIs related to hospital treatment or severe congenital renal abnormalities.

DATA EXTRACTION

After the quality assessment we extracted data on the given risk factor in children with and without UTI. The data were extracted separately for the occurrence and recurrence of UTIs.

RESULTS

We included 24 studies in the meta-analysis. Circumcision decreased the occurrence of UTIs with an odds ratio (OR) of 0.1 [95% confidence interval (CI): 0.06-0.17) and breast-feeding with an OR of 0.4 (CI: 0.19-0.86), both with low heterogeneity. Being overweight or obese increased the risk of UTI (OR: 2.23; CI: 1.37-3.63). Both poor fluid intake (OR: 6.39; CI: 3.07-13.39) and infrequent voiding (OR: 3.54; CI: 1.68-7.46) were associated with recurrent UTIs.

LIMITATIONS

The design, populations and definitions varied between the studies.

CONCLUSIONS

Being overweight or obese and having poor fluid intake are modifiable risk factors that increase the risk for UTIs in children. Breast-feeding and circumcision are associated with a decreased occurrence of UTIs.

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."

Model for predicting high-grade vesicoureteral reflux in young children presenting with febrile urinary tract infection

INTRODUCTION

High-grade vesicoureteral reflux (VUR) is associated with long-term renal outcome, and can be missed if voiding cystourethrogram (VCUG) is not performed. The current febrile urinary tract infection (UTI) guidelines have narrowed down the indications for VCUG. This study aimed to determine the predictors and develop a model to predict high-grade VUR (grade III-V) in young children presenting with febrile UTI.

METHODS

We retrospectively reviewed 324 children aged 2-60 months who presented with first or recurrent febrile UTI and underwent both renal and bladder ultrasonography (RBUS) and VCUG during 2004-2013. Multivariate logistic regression was used to identify independent predictors of high-grade VUR, and a predictive model and scoring system were developed. Sensitivity and specificity of the predictors were evaluated.

RESULTS

Sixty-two (67.4%) of 92 children with VUR were high-grade VUR. The independent risk factors for high-grade VUR were recurrent UTI (p < 0.001), non-Escherichia coli (non-E. coli) pathogen (p = 0.011), and abnormal RBUS (p < 0.001) including pelvicalyceal dilation only (p = 0.003), and with ureteric dilation (p < 0.001). Abnormal RBUS showed highest sensitivity (58.1%), while ureteric dilation had highest specificity (96.6%) to predict high-grade VUR. Combination of these predictors improved the specificity but decreased the sensitivity. The prediction score was calculated, as follows: recurrent UTI = 3 points + non-E. coli = 1 point + pelvicalyceal dilation only = 1 point + pelvicalyceal and ureteric dilation = 3 point. A cutoff score of 1 showed sensitivity of 82.3% and specificity of 63.7%. The specificity would increase (87.8, 92.7, 97.7, 100, 100, and 100%) for higher scores of 2, 3, 4, 5, 6 and 7, respectively.

DISCUSSION

High-grade VUR could be predicted by simple model using single or combined predictors. Sensitivity and specificity varied according to each predictor. The specificity of ureteral dilation was as high as recurrent UTI. The weighing score for each presenting predictor and the summation of the scores provided more detailed in sensitivity and specificity.

CONCLUSIONS

Children with febrile UTI who have the predictor(s) of high-grade VUR are recommended to undergo VCUG. The high-grade VUR prediction score may help for decision-making regarding whether to perform VCUG in a particular child.

Epidemiologic, microbiologic and imaging characteristics of urinary tract infections in hospitalized children < 2 years of age diagnosed with anatomic abnormalities of the urinary tract

BACKGROUND

To compare the epidemiologic, microbiologic and imaging characteristics of urinary tract infections (UTI) in children <2 years of age with and without anatomic urinary tract abnormalities (AA).

METHODS

All children hospitalized with UTI during 1.1.2005-31.12.2018 were included. The study group (patients with AA) included 76 patients. The control group (99 patients) included patients without AA.

RESULTS

1163 children were hospitalized. Age at diagnosis was younger in the study group vs. controls (5.2 ± 6.0 vs. 7.9 ± 7.5 months, P = 0.038). Uropathogens distribution was different (P = 0.007), with lower Escherichia coli (Ec) and Proteus mirabilis (Pm) percentages in the study group and higher percentages of Enterococcus spp. (Ent) in controls. In the study group, Ec nonsusceptibility rates to ampicillin, amoxicillin/clavulanic acid, cefazolin, cefuroxime, TMP/SMX and ceftriaxone were 58%, 40%, 14%, 14%, 12% and 10%, respectively, with no differences vs. controls. Ultrasound (US) was performed in 69/76 (98%) patients with AA (84.1%, abnormal); bilateral (39.7%) and unilateral (32.7%) ureteral dilatation were the most frequent findings. Voiding cystourethrography was performed in 46 patients (pathologic in 35, 76%); 31 (81.6%) patients had vesicoureteral reflux (VUR) (bilateral in 11, 35.5%; grade 4/5 in 7 patients). Uropathogens distribution in VUR patients differed between study and control groups, with lower Ec and Pm in the first group and higher Pseudomonas aeruginosa and Ent percentages in the control group.

CONCLUSION

Age at diagnosis was lower and pathogen distribution was different in patients with AA. Antibiotic susceptibility patterns of the main uropathogens were similar between patients with or without AA.

Impact of Early Oral Antibiotic Therapy in Infants With Bacteremic Urinary Tract Infections

OBJECTIVES

To determine the effect of early conversion to oral antibiotics in infants ≤90 days with gram-negative bacteremia and concomitant urinary tract infection on hospital length of stay (LOS) and 30-day revisits for urinary tract infection.

DESIGN

This retrospective cohort study included infants ≤ 90 days who had concomitant positive blood and urine cultures with gram-negative bacteremia at 22 hospitals from January 1, 2002 through January 31, 2020. Early oral conversion was defined as a maximum intravenous (IV) duration of 4 days. We conducted a noninferiority test to compare early oral conversion to long IV therapy. A propensity score framework was used to assess comparisons in survey-weighted regression models using matched weights.

RESULTS

Among 174 infants, 73 infants received early oral conversion. The LOS was shorter in infants receiving early oral conversion compared to long IV therapy (median 2 days [interquartile range 2, 3] vs 4 days [3, 5]), descriptively (P < .001) and in noninferiority analysis (ratio = 0.43; 90% CI 0.35, 0.53, P < .001). Thirty-day revisits occurred in 5 of 174 (2.8%) of total patients. Early oral conversion did not meet our noninferiority criteria for the 30-day revisits (odds ratio: 4.22, 90%; confidence interval: 0.83, 21.34, P = .91).

CONCLUSIONS

Early oral conversion was associated with shorter LOS. The rate of 30-day revisit rates overall was low.

Reflux nephropathy and scarring nephropathy: So close and yet so different

OBJECTIVES

Reflux nephropathy is a radiologic condition commonly used to express the existence of renal morphological lesions in patients who have or had vesicoureteral reflux (VUR). This morphological concept is used based on the image data collected, without conducting basic complementary renal function studies. The present study was designed to demonstrate that patients with active VUR present different functional renal alterations from those shown by patients with disappeared VUR.

METHODS

Longitudinal descriptive retrospective analysis including 89 children (46M, 43F) with VUR diagnosis through a standard voiding cystourethrogram (VCUG). The basic renal function tests collected were the maximum urinary osmolality (UOsm) and the urinary albumin/creatinine and NAG/creatinine ratios. The data collected corresponded to two moments, when VUR was diagnosed and when it had already disappeared.

RESULTS

Quantitative differences were verified in the three functional parameters when comparing those corresponding to both moments of the study. In the qualitative analysis, in relation to the intensity of the VUR, differences were observed in UOsm at diagnosis and in the albumin/creatinine ratio once the VUR had cured. At this last moment, a significant increase in the albumin/creatinine ratio was observed in patients with loss of renal parenchyma in relation to those without residual morphological lesions.

CONCLUSIONS

Concentrating ability defect is the most frequent finding in children with active reflux (true reflux nephropathy), whereas the most frequent functional disturbance found, once VUR has cured, is an increase in urinary albumin excretion, related to parenchymal damage. The term dysplastic-scarring nephropathy, could be more appropriate for patients with residual morphological lesions and impaired renal function, once VUR is cured.

Evaluation of renal function and scars in children with primary vesicoureteral reflux

OBJECTIVE

To evaluate growth, glomerular and tubular function, renal damage, scars in children affected by primary VUR.

METHOD

We retrospectively evaluated the clinical records of our Unit from January 2006 to September 2020. For each patient we evaluated growth, laboratoristic and scintigraphic glomerular and tubular function, renal damage and collective system urodynamics at baseline and at the last visit.

RESULT

We enrolled 41 patients affected by primary VUR and treated with continuous antibiotic prophylaxis. Glomerular function and urodynamics did not change over time. EFNa directly correlated with weight (r 0.44 p 0.004) and TRP inversely correlated with severity of reflux (r -0.32, p 0.04). Female sex was associated to nephrolithiasis (OR 17.0, p 0.02) and proteinuria (at T0 OR 5.8 p 0.03 at T1 OR 5.8, p 0.03). Daily proteinuria increased with age (r 0.66, p <0.0001 at T0 and r 0.44 p 0.004 at T1) while protein-to-creatinine ratio decreased. Renal scars at T0 inversely correlated with glomerular and tubular function at T1 but they did not correlate with severity or laterality of reflux.

CONCLUSION

Even if renal function remains stable through years, it is critical to identify the subjects with significant congenital renal damage.

Reassessment of the Role of Race in Calculating the Risk for Urinary Tract Infection: A Systematic Review and Meta-analysis

IMPORTANCE

A previously reported prediction model included a child's race to estimate risk of urinary tract infection (UTI), but race-conscious medicine encourages investigating how race is likely to be a proxy for other factors that should instead be used for risk prediction.

OBJECTIVES

To systematically review the available literature to evaluate the robustness of the association between race and UTI and to assess whether other variables could replace race as a variable in a previously developed prediction tool without adversely affecting its accuracy.

DATA SOURCE

MEDLINE was searched through May 28, 2021.

STUDY SELECTION

English-language studies that reported data on the prevalence of UTI according to race for children younger than 18 years were included.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers assessed studies for risk of bias and abstracted data. Random-effects models were used to pool odds ratios, and meta-regression was used to explore heterogeneity.

MAIN OUTCOMES AND MEASURES

Odds of UTI among non-Black children vs Black children.

RESULTS

Sixteen studies (17 845 children) were included. In the primary analysis, which included 11 studies, the pooled odds ratio of UTI among non-Black children was 2.44-fold higher (95% CI, 1.87-3.20) than among Black children. The corresponding odds ratio in studies with low or very low risk of bias was 4.84-fold higher (95% CI, 3.16-7.41; I2 = 0%) among non-Black children than among Black children. Replacing race with history of UTI and duration of fever resulted in a model with similar accuracy (training cohort: overall sensitivity, 96% [95% CI, 94%-98%]; overall specificity, 35% [95%, 32%-38%]; overall area under the receiver operating characteristic curve, 0.80 [95% CI, 0.77-0.82]; validation cohort: overall sensitivity, 97% [95% CI, 90%-100%]; overall specificity, 32% [95% CI, 26%-37%]; overall area under the receiver operating characteristic curve, 0.84 [95% CI, 0.77-0.92]).

CONCLUSIONS AND RELEVANCE

Although previous studies suggested that an association between race and UTI exists, because of the issues associated with the inclusion of race in decision models, we replaced the variable of race with history of UTI and duration of fever in a previously developed risk prediction model and found similar accuracy.

Contemporary Management of Urinary Tract Infections in Children

Purpose of Review

Urinary tract infection (UTI) in children is a major source of office visits and healthcare expenditure. Research into the diagnosis, treatment, and prophylaxis of UTI has evolved over the past 10 years. The development of new imaging techniques and UTI screening tools has improved our diagnostic accuracy tremendously. Identifying who to treat is imperative as the increase in multi-drug-resistant organisms has emphasized the need for antibiotic stewardship. This review covers the contemporary management of children with UTI and the data-driven paradigm shifts that have been implemented into clinical practice.

Recent Findings

With recent data illustrating the self-limiting nature and low prevalence of clinically significant vesicoureteral reflux (VUR), investigational imaging in children has become increasingly less frequent. Contrast-enhanced voiding urosonogram (CEVUS) has emerged as a useful diagnostic tool, as it can provide accurate detection of VUR without the need of radiation. The urinary and intestinal microbiomes are being investigated as potential therapeutic drug targets, as children with recurrent UTIs have significant alterations in bacterial proliferation. Use of adjunctive corticosteroids in children with pyelonephritis may decrease the risk of renal scarring and progressive renal insufficiency. The development of a vaccine against an antigen present on Escherichia coli may change the way we treat children with recurrent UTIs.

Summary

The American Academy of Pediatrics defines a UTI as the presence of at least 50,000 CFU/mL of a single uropathogen obtained by bladder catheterization with a dipstick urinalysis positive for leukocyte esterase (LE) or WBC present on urine microscopy. UTIs are more common in females, with uncircumcised males having the highest risk in the first year of life. E. coli is the most frequently cultured organism in UTI diagnoses and multi-drug-resistant strains are becoming more common. Diagnosis should be confirmed with an uncontaminated urine specimen, obtained from mid-stream collection, bladder catheterization, or suprapubic aspiration. Patients meeting criteria for imaging should undergo a renal and bladder ultrasound, with further investigational imaging based on results of ultrasound or clinical history. Continuous antibiotic prophylaxis is controversial; however, evidence shows patients with high-grade VUR and bladder and bowel dysfunction retain the most benefit. Open surgical repair of reflux is the gold standard for patients who fail medical management with endoscopic approaches available for select populations.

Impact of Third-Generation Cephalosporin Resistance on Recurrence in Children with Febrile Urinary Tract Infections

Background: The purpose of this study was to investigate the association between third-generation cephalosporin resistance and urinary tract infection (UTI) recurrence in patients who underwent voiding cystourethrogram (VCUG). Methods: In this retrospective study, data were obtained from hospitalized pediatric patients who had a first febrile UTI episode and subsequently underwent VCUG. Information based on VCUG was mandatory to identify the presence of vesicoureteral reflux (VUR). A multivariable logistic model was used to identify the risk factors for recurrence. Recurrence was divided into early (90-day) and late (1-year), and sensitivity analyses were performed according to each definition. The estimates of all the statistical models were internally validated using bootstrap samples. Results: A total of 210 patients were included, and the overall recurrence rate of UTI was 26.2% (55 of 210). Third-generation cephalosporin resistance was a significant risk factor for early recurrence (odds ratio: 2.79 [1.08–7.20]) but not for late recurrence. Sensitivity analyses showed that third-generation cephalosporin resistance was a significant risk factor for 60-day recurrence but not for 180-day recurrence. A VUR grade ≥ 3 was identified as a consistent risk factor for both early and late recurrence. Conclusions: Third-generation cephalosporin resistance was a significant risk factor for the early recurrence of pediatric UTI in patients who underwent VCUG.

Examination of Complementary Medicine for Treating Urinary Tract Infections Among Pregnant Women and Children

Urinary tract infections (UTIs) are a significant clinical problem that pregnant women and children commonly experience. Escherichia coli is the primary causative organism, along with several other gram-negative and gram-positive bacteria. Antimicrobial drugs are commonly prescribed to treat UTIs in these patients. Conventional treatment can range from using broad-spectrum antimicrobial drugs for empirical or prophylactic therapy or patient-tailored therapy based on urinary cultures and sensitivity to prospective antibiotics. The ongoing emergence of multi-drug resistant pathogens has raised concerns related to commonly prescribed antimicrobial drugs such as those used routinely to treat UTIs. Consequently, several natural medicines have been explored as potential complementary therapies to improve health outcomes in patients with UTIs. This review discusses the effectiveness of commonly used natural products such as cranberry juice/extracts, ascorbic acid, hyaluronic acid, probiotics, and multi-component formulations intended to treat and prevent UTIs. The combination of natural products with prescribed antimicrobial treatments and use of formulations that contained high amounts of cranberry extracts appear to be most effective in preventing recurrent UTIs (RUTIs). The incorporation of natural products like cranberry, hyaluronic acid, ascorbic acid, probiotics, Canephron® N, and Cystenium II to conventional treatments of acute UTIs or as a prophylactic regimen for treatment RUTIs can benefit both pregnant women and children. Limited information is available on the safety of natural products in these patients' populations. However, based on limited historical information, these remedies appear to be safe and well-tolerated by patients.

Tissue Immunity in the Bladder

The bladder is a major component of the urinary tract, an organ system that expels metabolic waste and excess water, which necessitates proximity to the external environment and its pathogens. It also houses a commensal microbiome. Therefore, its tissue immunity must resist pathogen invasion while maintaining tolerance to commensals. Bacterial infection of the bladder is common, with half of women globally experiencing one or more episodes of cystitis in their lifetime. Despite this, our knowledge of bladder immunity, particularly in humans, is incomplete. Here we consider the current view of tissue immunity in the bladder, with a focus on defense against infection. The urothelium has robust immune functionality, and its defensive capabilities are supported by resident immune cells, including macrophages, dendritic cells, natural killer cells, and γδ T cells. We discuss each in turn and consider why adaptive immune responses are often ineffective in preventing recurrent infection, as well as areas of priority for future research.

Risk Factors for the Development of Febrile Recurrences in Children with a History of Urinary Tract Infection

OBJECTIVE

To identify risk factors for febrile recurrence of urinary tract infections (UTIs) in children with a history of UTI.

STUDY DESIGN

We included 500 children aged 2-72 months with a history of UTI who were followed prospectively for approximately 2 years in the context of 2 previously conducted studies (Randomized Intervention for Children with Vesicoureteral Reflux and Careful Urinary Tract Infection Evaluation). We identified significant risk factors for febrile recurrences among children not receiving antimicrobial prophylaxis using univariate and multivariate logistic regression.

RESULT

On univariate analysis, non-Black race, febrile index UTI, bowel-bladder dysfunction, grade IV vesicoureteral reflux, renal scarring at baseline, and renal-bladder ultrasound abnormalities were associated with febrile recurrence. On multivariate analysis, the following variables independently increased the odds of febrile recurrences (OR; 95% CI): non-Black race (7.1; 1.5-127.9), bowel-bladder dysfunction (2.6; 1.1-5.3), febrile index UTI (2.5; 1.1-6.9), abnormalities on renal-bladder ultrasound scan (2.6; 1.2-5.6), grade IV vesicoureteral reflux (3.9; 1.4-10.5), and renal scarring at baseline (4.7; 1.2-19.1).

CONCLUSIONS

Non-Black race and grade IV vesicoureteral reflux increased the odds of febrile recurrence of UTI. Although our findings should stimulate other studies to further explore the relationship between race and UTIs, given that the link between race and UTI recurrence is unclear, race should not be used to make decisions regarding management of children with a UTI.

Risk factors for renal scarring and clinical morbidity in children with high-grade and low-grade primary vesicoureteral reflux

INTRODUCTION

Primary vesicoureteral reflux (VUR) is associated with urinary tract infections (UTIs) and renal damage. However, the importance of early diagnosis of VUR has been questioned. Moreover, most studies have few patients with high-grade VUR. Hence, we retrospectively analyzed a large cohort of patients with primary high-grade and low-grade VUR and assessed risk factors for renal damage and clinical morbidity.

MATERIAL AND METHODS

We included patients (<18 years) at diagnosis with low-grade (1-3) or high-grade (4-5) primary VUR and noted their clinical history and presence of hypertension, low eGFR (<60ml/in/1.73 m²), renal scarring (focal or generalised) and reduced differential renal function (DRF; <45%). Risk factors were assessed (in patients and renal units) by logistic regression and generalised estimating equation.

RESULTS

Of 399 primary VUR patients, 255 (64%) had high-grade VUR. Indications for voiding cystourethrogram were recurrent UTI (38%), first UTI (28%) and antenatal hydronephrosis (17%). At diagnosis, 252 (65%) had renal scars (focal in 170 [44%], generalised in 82 [21%]), and 188 (47%) had reduced DRF. High-grade VUR patients were more likely than low-grade VUR patients to have renal scarring (75% vs. 49%, p < 0.01), low eGFR (23% vs. 13%, p = 0.04) and significant hypertension (26% vs. 13%, p = 0.02). High-grade VUR was associated with generalised scars (odds ratio [OR] 11, p < 0.001), focal scars (OR 3.1, p < 0.001) and reduced DRF (OR 2.3, p < 0.001) shown in the table. Male sex was a risk factor for generalised scars (OR 2.3, p = 0.005). Focal scars were associated with recurrent UTIs (OR = 1.8, p = 0.004) and reduced DRF (OR 1.4, p = 0.027). Patients with multiple focal scars were diagnosed at an older age (2 years [1,4] than those with single scars (1.5 years [1,4] or no scars (1 year [0, 3]), p = 0.04).

DISCUSSION

The prevalence of renal damage and clinical morbidity at VUR diagnosis was higher than other studies. High-grade VUR patients had a greater prevalence of renal damage, low eGFR and hypertension than low-grade VUR patients and was a risk factor for focal scars, generalised scars and reduced DRF. Focal scars were independently associated with recurrent UTI. Those with multiple scars were diagnosed later than those with single scars or no scars.

CONCLUSIONS

High-grade VUR was associated with renal damage and clinical morbidity. Our study highlights the importance of diagnosing VUR early to identify patients who may warrant long-term follow-up and intervention to minimize morbidity.

Kidney Echogenicity and Vesicoureteral Reflux in Children with Febrile Urinary Tract Infection

OBJECTIVE

To evaluate increased kidney echogenicity as a predictor of vesicoureteral reflux (VUR) in young children with first febrile urinary tract infection (UTI).

STUDY DESIGN

We performed a single center retrospective study of hospitalized children with first febrile UTI diagnosed in accordance with the American Academy of Pediatrics guidelines. All patients had kidney bladder ultrasound (KBUS) and voiding cystourethrography. Variables analyzed using χ² test or Mann-Whitney U test as appropriate. Multivariable logistic regression analysis was performed for the abnormal KBUS findings and OR and 95% CI were calculated.

RESULTS

Our cohort included 415 children (830 kidney units) with median age of 5 months (1 month to 5 years) and 80% were female. One hundred thirty-two (31.8%) patients had abnormal KBUS, including increased echogenicity in 45 patients. Overall, 42.2% of patients with increased echogenicity had VUR vs 23.3% with normal ultrasound (P = .013) and 31.1% of patients with increased echogenicity had high-grade III-V VUR vs 8.1% with normal ultrasound (P = .001). In total, 24.3% of kidneys with increased echogenicity had VUR vs 20% with normal ultrasound (P = .246) and 20% of kidneys with increased echogenicity had high-grade III-V VUR vs 9.9%with normal ultrasound (P = .005).

CONCLUSIONS

These data support adding increased kidney echogenicity to the list of other KBUS findings that are helpful in decision making about a need for voiding cystourethrography in young children with first febrile UTI.

Prediction of Recurrent Urinary Tract Infection in Paediatric Patients by Deep Learning Analysis of 99mTc-DMSA Renal Scan

Purpose: Tc-99m dimercaptosuccinic acid (^99mTc-DMSA) renal scan is an important tool for the assessment of childhood urinary tract infection (UTI), vesicoureteral reflux (VUR), and renal scarring. We evaluated whether a deep learning (DL) analysis of ^99mTc-DMSA renal scans could predict the recurrence of UTI better than conventional clinical factors. Methods: the subjects were 180 paediatric patients diagnosed with UTI, who underwent immediate post-therapeutic ^99mTc-DMSA renal scans. The primary outcome was the recurrence of UTI during the follow-up period. For the DL analysis, a convolutional neural network (CNN) model was used. Age, sex, the presence of VUR, the presence of cortical defects on the ^99mTc-DMSA renal scan, split renal function (SRF), and DL prediction results were used as independent factors for predicting recurrent UTI. The diagnostic accuracy for predicting recurrent UTI was statistically compared between independent factors. Results: The sensitivity, specificity and accuracy for predicting recurrent UTI were 44.4%, 88.9%, and 82.2% by the presence of VUR; 44.4%, 76.5%, and 71.7% by the presence of cortical defect; 74.1%, 80.4%, and 79.4% by SRF (optimal cut-off = 45.93%); and 70.4%, 94.8%, and 91.1% by the DL prediction results. There were no significant differences in sensitivity between all independent factors (p > 0.05, for all). The specificity and accuracy of the DL prediction results were significantly higher than those of the other factors. Conclusion: DL analysis of ^99mTc-DMSA renal scans may be useful for predicting recurrent UTI in paediatric patients. It is an efficient supportive tool to predict poor prognosis without visually demonstrable cortical defects in ^99mTc-DMSA renal scans.