Risk Factors for Recurrent Urinary Tract Infection and Renal Scarring

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.

Short Intravenous Antibiotic Courses for Urinary Infections in Young Infants: A Systematic Review

CONTEXT

Urinary tract infections (UTIs) are common in young infants, yet there is no guidance on the optimal duration of intravenous (IV) treatment.

OBJECTIVE

To determine if shorter IV antibiotic courses (≤7 days) are appropriate for managing UTIs in infants aged ≤90 days.

METHODS

PubMed, the Cochrane Library, Medline, and Embase (February 2021) were used as data sources. Included studies reported original data for infants aged ≤90 days with UTIs, studied short IV antibiotic durations (≤7 days), and described at least 1 treatment outcome. The Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline was followed. Studies were screened by 2 investigators, and bias was assessed by using the Newcastle-Ottawa Scale and the Revised Cochrane Risk-of-Bias Tool.

RESULTS

Eighteen studies with 16 615 young infants were included. The largest 2 studies on bacteremic UTI found no difference in the rates of 30-day recurrence between those treated with ≤7 vs >7 days of IV antibiotics. For nonbacteremic UTI, there was no significant difference in the adjusted 30-day recurrence between those receiving ≤3 vs >3 days of IV antibiotics in the largest 2 studies identified. Three studies of infants aged ≥30 days used oral antibiotics alone and reported good outcomes, although only 85 infants were ≤90 days old.

CONCLUSIONS

Shorter IV antibiotic courses of ≤7 days and ≤3 days with early switch to oral antibiotics should be considered in infants aged ≤90 days with bacteremic and nonbacteremic UTI, respectively, after excluding meningitis. Further studies of treatment with oral antibiotics alone are needed in this age group.

Urinary Tract Infections in Children with Vesicoureteral Reflux Are Accompanied by Alterations in Urinary Microbiota and Metabolome Profiles

Children with vesicoureteral reflux (VUR) are at an increased risk of recurrent urinary tract infections (UTIs) and renal scarring. Gut microbiota are associated with disease phenotypes, but there has been no study that associates urinary microbiota (uMB) and metabolic profiles with VUR pathology. To identify dominant uMB genera and metabolites associated with UTIs in VUR, urine samples collected under sterile conditions underwent 16S ribosomal RNA sequencing (n = 49) and metabolomic analysis by mass spectrometry (n = 96). Alterations in uMB and metabolomic profiles in VUR patients suggest remodeling of urinary bacterial communities after UTIs: Dorea- and Escherichia-dominant uMB profiles were more frequently identified in participants with VUR. Prevotella- and Lactobacillus-dominant uMB profiles were more prevalent in controls (p < 0.001). Microbial composition varied based on recurrent febrile UTI status (p = 0.001). A total of 243 urinary metabolites involved in energy, amino acid, nucleotide, and lipid metabolism were altered in VUR patients with UTIs (p < 0.05). Importantly, VUR specimens revealed changes in the bacteria-associated metabolic pathways such as glutamate degradation, methyl-citrate cycle, and bile acid metabolism. PATIENT SUMMARY: Differences in urinary commensal bacteria and metabolites exist between children with and without vesicoureteral reflux (VUR). These changes may be utilized to identify patients at risk of VUR-associated kidney damage.

Clinical Outcome of Discordant Empirical Therapy and Risk Factors Associated to Treatment Failure in Children Hospitalized for Urinary Tract Infections

With the spread of antibiotic resistance in pediatric urinary tract infections (UTIs), more patients are likely to be started empirically on antibiotics to which pathogens are later found to be resistant (discordant therapy). However, in-vivo effectiveness may be different from in-vitro susceptibility. Aims of this study were to describe clinical outcomes of discordant empirical treatments in pediatric UTIs and to investigate risk factors associated to treatment failure. This observational, retrospective study was conducted on children hospitalized for febrile UTIs with positive urine culture and started on discordant empirical therapy. Failure rates of discordant treatments and associated risk factors were investigated. A total of 142/1600 (8.9%) patients were treated with inadequate empirical antibiotics. Clinical failure was observed in 67/142 (47.2%) patients, with no fatal events. Higher failure rates were observed for combinations of penicillin and beta-lactamase inhibitors (57.1%). Significant risk factors for failure of discordant treatment were history of recurrent UTIs (95% CI: 1.13–9.98, OR: 3.23, p < 0.05), recent use of antibiotics (95% CI: 1.46–21.82, OR: 5.02, p < 0.01), infections caused by Pseudomonas aeruginosa (95% CI: 1.85–62.10, OR: 7.30, p < 0.05), and empirical treatment with combinations of penicillin and beta-lactamase inhibitors (95% CI: 0.94–4.03, OR: 1.94, p = 0.05). This study showed that discordant empirical treatments may still be effective in more than half of pediatric UTIs. Clinical effectiveness varies between different discordant antibiotics in pediatric UTIs, and patients presenting risk factors for treatment failure may need a differentiated empirical approach.

New Insights from Metabolomics in Pediatric Renal Diseases

Renal diseases in childhood form a spectrum of different conditions with potential long-term consequences. Given that, a great effort has been made by researchers to identify candidate biomarkers that are able to influence diagnosis and prognosis, in particular by using omics techniques (e.g., metabolomics, lipidomics, genomics, and transcriptomics). Over the past decades, metabolomics has added a promising number of ‘new’ biomarkers to the ‘old’ group through better physiopathological knowledge, paving the way for insightful perspectives on the management of different renal diseases. We aimed to summarize the most recent omics evidence in the main renal pediatric diseases (including acute renal injury, kidney transplantation, chronic kidney disease, renal dysplasia, vesicoureteral reflux, and lithiasis) in this narrative review.

Evaluation of platelet indices in children with renal scarring based on diagnostic accuracy criteria and Cohen's kappa

BACKGROUND

Renal scarring is a significant complication in recurrent urinary tract infections (UTIs) in children that can lead to hypertension and end-stage renal disease. The present study evaluates whether platelet indices may be predictive of renal scarring.

METHODS

Sixty-nine patients aged 1-18 years with recurrent UTIs, whose medical records were reviewed to collect data on the presence of upper/lower UTIs and the results of scintigraphic investigations with 99m-technetium dimercaptosuccinic acid, were included in the study. The platelet, platelet indices (mean platelet volume [MPV]), platelet distribution width, plateletcrit, and C-reactive protein (CRP) values of the patients during UTI episodes were reviewed retrospectively.

RESULTS

Mean platelet volume and CRP values were higher in the renal scarring group than in the non-renal scarring group (P < 0.001 and P = 0.003, respectively). Increases in MPV and CRP values were independent risk factors for renal scarring (OR = 5.781 [1.431-23.347] and OR = 1.922 [1.77-3.141], respectively). The sensitivity, specificity, positive and negative predictive values, and diagnostic odds ratio values of MPV at a cut-off of >8.2 fL for renal scarring discrimination were 62.5%, 88.89%, 75.00%, 81.63%, and 13.33 [1.35-3.83], respectively. The sensitivity, specificity, positive and negative predictive values, and diagnostic odds ratio values of CRP at a cut-off of 1.97 mg/L for renal scarring were 58.33%, 91.11%, 77.78%, 80.39%, and 14.35 [1.36-3.97], respectively.

CONCLUSION

Both MPV and CRP can be used as predictive markers for renal scarring. While MPV had higher sensitivity, CRP had a higher specificity and diagnostic odds ratio in predicting renal scarring.

Risk factors for breakthrough urinary tract infection in children with vesicoureteral reflux receiving continuous antibiotic prophylaxis

BACKGROUND

To investigate the risk factors for breakthrough urinary tract infection (BT-UTI) in children with vesicoureteral reflux (VUR) receiving continuous antibiotic prophylaxis (CAP).

METHODS

This was a single-centre cohort study (January 2016 to December 2019). The clinical data of 256 children with grade I-V VUR receiving CAP were analysed. In this study, exposure variables were sex, younger age at the initial diagnosis of UTI ≤12 months, high-grade VUR, bilateral VUR, aetiology, presence of renal scarring at the initial diagnosis, presence of renal function impairment at the initial diagnosis, ultrasound abnormalities, antibiotic used and bladder and bowel dysfunction (BBD). Outcome was BT-UTI.

RESULTS

BT-UTI occurred in 81 out of 256 children with grade I-V VUR who received CAP, an incidence of 31.64%. Univariate analysis showed that younger age at the initial diagnosis of UTI (≤12 months), bilateral VUR, renal scarring on the dimercaptosuccinic acid (DMSA) scan at the initial diagnosis of UTI and BBD were correlated with the occurrence of BT-UTI. Multivariate analysis showed that younger age at the initial diagnosis of UTI (≤12 months) [hazard ratio (HR): 4.629; 95% confidence interval (CI): 1.302-16.462], bilateral VUR (HR: 2.078; 95% CI: 1.084-4.022) and BBD (HR: 3.194; 95% CI: 1.243-8.206) were independent risk factors for the occurrence of BT-UTI.

CONCLUSIONS

For VUR children receiving CAP, younger age at the initial diagnosis of UTI (≤12 months), bilateral VUR, and BBD were independent risk factors for the occurrence of BT-UTI.

Extravesical vs. intravesical ureteric reimplantation for primary vesicoureteral reflux: A systematic review and meta-analysis

PURPOSE

This study aims to compare the outcomes of extravesical (EVUR) and intravesical (IVUR) ureteric reimplantation for primary vesicoureteral reflux (VUR) via systematic review and meta-analysis.

METHODS

Literature review from Medline, Embase, and Cochrane since inception to March 2022 was performed. Meta-analysis was conducted on eligible randomized controlled trials (RCT) and observational cohort studies (OCS) comparing outcomes between EVUR and IVUR.

RESULTS

Twelve studies were included, comprising 577 patients (778 ureters) operated by EVUR and 395 patients (635 ureters) by IVUR. Pre-operative VUR grade, postoperative VUR persistence and hydronephrosis was not statistically significant. EVUR had shorter operative time [mean differences (MD) -22.91 min; 95% confidence interval (CI), -44.53 to -1.30, P = 0.04] and hospital stay (MD -2.09 days; 95% CI, -2.82 to -1.36, P < 0.00001) compared to IVUR. Bilateral EVUR had higher risk of postoperative acute urinary retention (ARU) (8.1%) compared to bilateral IVUR (1.7%) (OR = 4.40; 95% CI, 1.33-14.58, P = 0.02). No patient undergoing unilateral EVUR or IVUR experienced ARU.

CONCLUSION

Both EVUR and IVUR are equally effective in correcting primary VUR. Operative time and hospital stay are shorter after EVUR compared to IVUR. However, bilateral EVUR is associated with higher risk of postoperative ARU.

Pediatric urology research in 2020: A bibliometric analysis of the top 100 most cited articles

BACKGROUND

Pediatric Urology deals with genitourinary diseases. Present study aimed to collect the top-cited article in Pediatric Urology in order to define the most debated and studied topics.

METHODS

The journals reported in "Urology & Nephrology" category of the 2019 edition of Journal Citation Reports, together with the most relevant journals of "Transplantation," "Pediatrics," and "Surgery" categories, were browsed. The articles of interest in Pediatric Urology with more than 50 citations were collected. A bibliometric analysis was performed to collect the top 100 cited articles.

RESULTS

The top-cited articles were published in 27 journals (23%), with a median impact factor of 2.676 (IQR 1.981-5.642). Seventeen of them (63%) belonged to "Urology and Nephrology" category. The median number of citations was 82 (IQR 64-113). The most productive journal, with 23 articles, was "The Journal of Urology." Forty-eight top-cited articles were Guidelines or Reviews of the literature and only four papers were randomized controlled trials. The most relevant topic was "congenital anomalies" with 18 articles. As to minimally invasive surgery, eight studies were identified. All of them dealt with robotic-assisted laparoscopic surgery. Two articles reported the current evidence about transitional care.

CONCLUSIONS

The top-cited articles were dispersed among journals of different areas. Current scientific literature deal with congenital anomalies, more specifically with obstructive uropathies and hypospadias. In the last decade, one of the most relevant innovation in pediatric urology was the introduction of robotic surgery. Transitional care has become a timely topic.

An Important Risk Factor Affecting Hypercalciuria in Children: Vesicoureteral Reflux

INTRODUCTION

 A large number of genes and environmental factors, like dietary habits, play a role in the development of hypercalciuria in children. In this study, we aimed to determine the effects of the presence and grade of vesicoureteral reflux (VUR) on hypercalciuria status in children.

MATERIALS AND METHODS

 Data for 165 patients who admitted to the Pediatric Urology Department were retrospectively analyzed. The patients were composed of following four different groups: (1) urinary stone patients, (2) VUR patients under follow-up, (3) corrected VUR patients, and (4) control. The demographic features, clinical data, and laboratory tests for the groups were compared.

RESULTS

 The mean age of the patients was 100.6 ± 54.69 months and the female/male ratio was 79:86. The mean urinary calcium/creatinine (UCa/Cr) excretion and the frequency of high UCa/Cr ratios in the corrected VUR group were similar to those in the control group (p = 0.375 and 0.965, respectively). In contrast, the mean UCa/Cr excretion and frequency of high UCa/Cr ratios in the urinary stone and follow-up VUR groups were significantly higher than those in the corrected VUR group (p < 0.001, < 0.001, 0.003, and 0.029, respectively). The mean UCa/Cr excretion and frequency of high UCa/Cr ratios in the follow-up VUR group were similar to those in the urinary stone group (p = 0.323 and 0.425, respectively). In the follow-up VUR group, although reflux laterality had no effect on the UCa/Cr ratios (p = 0.180 and 0.108, respectively), the mean and frequency of high UCa/Cr ratios were higher in high-grade reflux cases (p < 0.001 and p = 0.042, respectively).

CONCLUSION

 Both the mean UCa/Cr ratio and the rate of hypercalciuria in the corrected reflux group were significantly lower than the corresponding values in the follow-up VUR and urinary stone groups. Further, the follow-up VUR patients had similar urinary calcium excretion levels as the stone patients. VUR treatment is associated with a decrease in urinary calcium excretion to the normal population level. A positive correlation between reflux degree and calcium excretion was observed.

Importance of Antimicrobial Stewardship in the Treatment of Urinary Tract Infection

Urinary tract infection (UTI) is a microbial contamination of the bladder and related organs. Study subjects were those who had no structural anomaly and no co-occurring diseases, such as diabetes, or were either immunocompromised or pregnant. Simple UTI is also defined as cystitis or inferior UTI. This study was a prospective, single center study conducted at a tertiary level clinic and its associated bacteriology laboratory. Patients whose urine tests were collected by the microbiology test center over a 6-month period were enrolled in the study. Culture and vulnerability results were obtained directly from the microbiology test center. Of the 1306 samples obtained, 888 (68%) were from females and 418 (32%) from males. This study identified the predominant UTI-causing microbes and the associated antimicrobial vulnerabilities. In males, Escherichia coli (36.8%) was the predominant microbe followed by Klebsiella pneumoniae 19.8%, Proteus spp. 17.4%, Staphylococcus aureus 10.0%, Pseudomonas aeruginosa 5.5%, Citrobacter spp. 5.0%, Staphylococcus saprophyticus 0.7%, Enterococcus faecalis 1.4%, and Acinetobacter spp. 0.7%. In females, E. coli (49.4%) was predominant, whereas Acinetobacter spp. (0.3%) was the least dominant. The considerable susceptibility of E. coli to meropenem (73.6%) and imipenem (73.5%) was similar to that reported in different investigations across India. In this study, the susceptibility of E. coli to piperacillin + tazobactam and ciprofloxacin was 42.7% and 14.3%, respectively. Stewardship of urinalysis and urine culture, especially among clinicians might be a successful upstream strategy for reducing inappropriate antimicrobial use for UTI. Thus, it is critical to routinely screen for resistance or susceptibility in samples of uropathogens, so the protocols for proper antibiotic treatment can be enhanced to incorporate antimicrobials with less resistance, supporting physicians in the appropriate treatment of UTIs resulting in insignificant remedial disappointments.

Non-antibiotic interventions for prevention of urinary tract infections in children: a systematic review and meta-analysis of randomized controlled trials

A considerable proportion of children experience a recurrence of urinary tract infection (UTI) following the first episode. While low-dose antibiotic prophylaxis has been the mainstay for the prevention of UTI, recent evidence raised concerns over their efficacy and safety. Hence, we aim to systematically synthesize evidence on the efficacy and safety of non-antibiotic prophylactic interventions for UTI. Using keywords related to study population (children) and intervention (non-antibiotic), we searched CENTRAL, Embase, PubMed, and Web of Science for randomized controlled trials (RCTs) published until August 2020. RCTs comparing any non-antibiotic interventions with placebo/antibiotics for prevention of UTIs in children were considered eligible. We used a random-effect model to provide pooled estimates. Sixteen trials evaluating 1426 participants were included. Cranberry was as effective as antibiotic prophylaxis (RR: 0.92; 95% CI: 0.56-1.50) but better than placebo/no therapy (RR: 0.48; 95% CI: 0.28-0.80) in reducing UTI recurrence. Probiotic therapy was more effective in reducing UTI recurrence (RR: 0.52; 95% CI: 0.29-0.94) when compared with placebo. While probiotic therapy was not better than antibiotics prophylaxis in preventing UTI (RR: 0.82; 95% CI: 0.56-1.21), they have a lower risk of antibiotic resistance (RR: 0.38; 95% CI: 0.21-0.69).Conclusion: Cranberry products and probiotics are the two non-antibiotic interventions that have been chiefly evaluated, reduce the risk of UTI recurrence when compared with placebo in children with a normal urinary tract. The findings from this systematic review suggest that while cranberry and probiotics may be used, there is a definite need to identify better and more acceptable non-antibiotic interventions. What is Known: • Efficacy of the low-dose antibiotic is controversial in preventing UTI and it is associated with increase in the risk of antimicrobial resistance. • Non-antibiotic interventions such as cranberry products are effective in preventing UTI recurrence in adults. What is New: • Cranberry products are effective in reducing the recurrence of UTI in children with normal urinary tract. • Low-quality evidence suggests that probiotics can be a potential prophylactic measure to reduce recurrence of UTI in the pediatric population.

Ribonuclease 7 polymorphism rs1263872 reduces antimicrobial activity and associates with pediatric urinary tract infections

Ribonuclease 7 (RNase 7) is an antimicrobial peptide that prevents urinary tract infections (UTI); however, it is yet unknown how RNASE7 genetic variations affect its antimicrobial activity and its mitigation of UTI risk. This study determined whether the RNASE7 SNP rs1263872 is more prevalent in children with UTI and defined how rs1263872 affects RNase 7's antimicrobial activity against uropathogenic E. coli (UPEC). We performed genotyping for rs1263872 in 2 national UTI cohorts, including children enrolled in the Randomized Intervention for Children with Vesicoureteral Reflux trial or the Careful Urinary Tract Infection Evaluation study. Genotypes from these cohorts were compared with those of female controls with no UTI. To assess whether rs1263872 affects RNase 7's antimicrobial activity, we generated RNase 7 peptides and genetically modified urothelial cultures encoding wild-type RNase 7 and its variant. Compared with controls, girls in both UTI cohorts had an increased prevalence of the RNASE7 variant. Compared with the missense variant, wild-type RNase 7 peptide showed greater bactericidal activity against UPEC. Wild-type RNase 7 overexpression in human urothelial cultures reduced UPEC invasive infection compared with mutant overexpression. These results show that children with UTI have an increased prevalence of RNASE7 rs1263872, which may increase UTI susceptibility by suppressing RNase 7's antibacterial activity.

[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.

PATIENTS AND 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.

Constipation on abdominal radiograph as potential risk factor for recurrent urinary tract infection development

BACKGROUND

To compare clinical history and measurements of fecal load on abdominal radiography (AR) in the prediction of urinary tract infection (UTI) recurrence in children.

METHODS

We combined data from two multicenter longitudinal studies in which children less than 6 years of age with a first or second UTI were followed for recurrence of UTI. Two radiologists reviewed the scout abdominal radiographs of initial voiding cystourethrograms obtained at enrollment from children at two participating sites and measured stool visible in various parts of the colon. We examined how well clinical variables (e.g., voiding and bowel history, use of laxatives at enrollment) and measurements of fecal load predicted recurrence of UTI within 12 months of enrollment.

RESULTS

One hundred and ninety-two children were included. On univariate analyses, age, vesicoureteral reflux (VUR), cecal diameter, rectal diameter, and total stool length on AR were associated with recurrence of UTI. After controlling for age, the odds of recurrent UTI in children with VUR at baseline was 3.85 (95% CI: 1.62, 9.14) higher than in children without VUR. Recurrent UTI was 2.57 (95% CI: 1.01, 6.55) times more likely in children with cecal diameter > 3.10 cm than children with lower cecal diameters; time to first recurrent UTI was shorter in children with elevated cecal diameters (p = 0.0023).

CONCLUSIONS

Cecal diameter on abdominal radiographs predicts UTI recurrence in children with a previous UTI. However, its accuracy is suboptimal to serve as a screening test. Accordingly, its routine use for this indication is not supported. If cecal diameter on an AR ordered for another indication is > 3.10 cm, then management of constipation could be considered.

Risk factors for kidney scarring and vesicoureteral reflux in 421 children after their first acute pyelonephritis, and appraisal of international guidelines

BACKGROUND

Acute pyelonephritis (AP) is a common bacterial infection in childhood. Follow-up guidelines on these children are controversial. This study aimed to identify risk factors for kidney scarring and vesicoureteral reflux (VUR). Furthermore, international follow-up guidelines were used for simulation to evaluate sensitivity and specificity.

METHODS

Urinary culture-confirmed first-time AP patients (aged 0-14 years) were enrolled (n = 421) from review of patient charts. All underwent kidney ultrasound (US) and a technetium-99m-dimercaptosuccinic acid (DMSA) scan or technetium-99m-mercaptoacetyltriglycine scinti-renography (MAG3) at 4-6 months of follow-up. The international guidelines used for simulation were from the National Institute of Health UK (NICE), the American Association of Paediatrics (AAP) and the Swedish Paediatric Society (SPS).

RESULTS

17.8% presented with an abnormal DMSA/MAG3 at follow-up, 7.1% were diagnosed with VUR grades III-V and 4.7% were admitted for surgery. Non-Escherichia coli infections, abnormal kidney US, elevated creatinine and delayed response to treatment (>48 h) were risk factors for abnormal DMSA findings and VUR grades III-V. NICE and SPS guidelines showed best sensitivity in diagnosing VUR grades III-V (75%) compared with AAP (56%).

CONCLUSIONS

Risk factors are helpful in identifying the children in need of further investigations and minimizing invasive work-up for the rest. International guidelines on follow-up detect a varying number of children with kidney damage and/or significant VUR. Future work must focus on identifying more specific risk factors, better imaging, or specific biomarkers, to enhance sensitivity and specificity in detecting the children at high risk for developing recurrent infections and/or nephropathy.

Long-term follow-up of premature infants with urinary tract infection

Urinary tract infection (UTI) is common in preterm infants and may have long-term sequela, such as recurrent infections and renal scarring in older children. We assessed long-term outcomes of preterm infants with UTI, born during 1996-2008 in Schneider Children's Medical Center's neonatal intensive care unit (NICU), and incidence of UTI recurrence. Of 89 preterm infants, seven were excluded due to prenatal diagnosis of congenital anomalies of the kidney and urinary tract (CAKUT), 41 interviewed by phone, 18 presented for follow-up evaluation in the nephrology clinic, and 23 lost to follow-up. No patient who completed follow-up reported additional UTI episodes or issues related to kidney and urinary tract. Clinically evaluated participants were 17.1 ± 3.6 years, born prematurely at 29.4 ± 4 weeks. All had a normal estimated glomerular filtration rate of >90 ml/min/1.73m²; four (22%) had systolic blood pressure >90th percentile; none had proteinuria (mean protein/creatinine ratio 0.09 ± 0.04 mg/mg) or albuminuria (mean albumin/creatinine ratio 10.2 ± 6.3 mcg/mg). Renal ultrasonography done in the first years of life in 12 (66%) patients demonstrated normal kidney size and structure.Conclusion: In this pilot study, a single episode of UTI in premature infants without CAKUT did not constitute a risk factor for recurrence of infections or kidney injury in their first two decades of life. Thus, normal ultrasound in NICU excluding CAKUT may be sufficient for premature patients with UTI, with no need of further imaging or long-term nephrology follow-up. What is Known: • Urinary tract infection (UTI) is one of the most common bacterial infections in neonates and premature infants. Risk factors for UTI recurrence in children are congenital anomalies of the kidney and urinary tract (CAKUT) and bladder and bowel dysfunction. • The recurrence rate and long-term renal sequela of UTI in preterm infants have not been studied. Guidelines regarding management and long-term follow-up for infants less than 2 months old are lacking. What is New: • A single episode of UTI in premature infants without CAKUT probably does not constitute a risk factor for UTI recurrence, and it is unlikely to cause renal injury in the first two decades of life. • For premature infants with UTI without sonographic diagnosis of CAKUT in NICU, prophylactic antibiotic treatment, further imaging, or long-term nephrology follow-up may be unnecessary.

Armamentarium to treat primary vesicoureteral reflux in children

Primary vesicoureteral reflux often spontaneously resolves in children. However, in select patients, untreated reflux can contribute to recurrent pyelonephritis leading to irreversible renal damage. Management is therefore based on a given child's likelihood of recurrent urinary tract infections and risk of subsequent renal parenchymal injury. Therapeutic options for urinary reflux are diverse, ranging from observation with or without continuous low-dose antibiotic prophylaxis to a variety of operative interventions.

Role of the urinary N-acetyl-beta-D-glucosaminidase/creatinine (NAG/Cr) ratio in discriminating between true and false pyuria in sterile urine bag specimens

INTRODUCTION

Urethral catheterization (CATH) and suprapubic aspiration (SA) are reliable methods of collecting urine for the diagnosis of urinary tract infections (UTIs), but both are invasive and difficult. Therefore, urine collection through a sterile urine bag (SUB) is commonly used for UTI screening. However, when pyuria is found in SUB specimens, it is difficult to interpret whether this result is true or false.

OBJECTIVE

We aimed to determine the diagnostic performance of the urinary NAG/Cr ratio in detecting true pyuria in SUB specimens for children with suspected UTIs.

STUDY DESIGN

This retrospective study included children 2-24 months of age presenting to the pediatric emergency department (PED) and in whom urinary NAG and creatinine levels were measured and a urine culture was performed between January 1, 2018, and December 31, 2019. Children with the presence of pyuria in SUB specimens were categorized into true or false pyuria groups depending on whether pyuria was present in CATH specimens. The diagnostic performance of the urinary NAG/Cr ratio in detecting true pyuria was identified using receiver operating characteristic (ROC) curve analysis. The optimal cutoff was calculated based on ROC curve analysis. Sensitivity, specificity, and positive and negative likelihood ratios were assessed for optimal cutoff values.

RESULTS

Among 606 children with measured urinary NAG levels, 144 children with pyuria in SUB specimens were included in the analyses. Pyuria was consistently present in the CATH specimens of 67 (46.5%) children and absent in those of 77 (44.5%) children. The urinary NAG/Cr ratio was significantly higher in the true pyuria group than in the false pyuria group (21.5 IU/g; 95% confidence interval [CI]: 12.3-35.6; vs 9.6 IU/g; 95% CI: 6.7-16.1, P < 0.001). The area under the ROC curve (AUC) for the urinary NAG/Cr ratio was 0.776 (95% CI: 0.700-0.851). The optimal cutoff of 18.85 IU/g corresponded to the best combination of sensitivity (58.2, 95% CI: 46.4-70.0) and specificity (83.3, 95% CI: 74.7-91.6), with positive and negative likelihood ratios of 3.49 (95% CI: 2.04-5.97) and 0.50 (95% CI: 0.37-0.68), respectively.

CONCLUSION

The urinary NAG/Cr ratio may be a potential indicator discriminating true pyuria from false pyuria in SUB specimens in the PED. However, large prospective studies are required to implement the NAG/Cr ratio in clinical practice.

Neutrophil gelatinase-associated lipocalin for urinary tract infection and pyelonephritis: a systematic review

BACKGROUND

The sensitivity and specificity of the leukocyte esterase test are relatively low for a screening test for urinary tract infection (UTI). More accurate tests could reduce both overtreatment and missed cases. This study aimed to determine whether neutrophil gelatinase-associated lipocalin (NGAL) can replace leukocyte esterase in the diagnosis of UTI and/or whether NGAL accurately identifies children with acute pyelonephritis.

METHODS

Data sources-MEDLINE and EMBASE. We only considered published studies that evaluated the results of an index test (NGAL) against the results of urine culture (for UTI) or against the results of dimercaptosuccinic acid (for acute pyelonephritis) in children aged 0 to 18 years. Two authors independently applied the selection criteria to all citations and independently extracted the data.

RESULTS

A total of 12 studies met our inclusion criteria. Four studies (920 children) included data on NGAL for UTI; eight studies (580 children) included data on NGAL for pyelonephritis. We did not pool accuracy values because the included studies used different cutoff values. For the diagnosis of UTI, urinary NGAL appeared to have better accuracy than the leukocyte esterase test in all included studies. For the diagnosis of pyelonephritis, neither plasma NGAL nor urinary NGAL had high sensitivity and/or specificity. The number of studies was the main limitation of this systematic review.

CONCLUSIONS

Urinary NGAL appears promising for the diagnosis of UTI; however, larger studies are needed to validate this marker as a replacement for leukocyte esterase. The use of NGAL for diagnosing acute pyelonephritis requires further study.

Diagnosis and management of community-acquired urinary tract infection in infants and children: Clinical guidelines endorsed by the Saudi Pediatric Infectious Diseases Society (SPIDS)

Urinary tract infection (UTI) is the most common bacterial disease in childhood worldwide and may have significant adverse consequences, particularly for young children. In this guideline, we provide the most up-to-date information for the diagnosis and management of community-acquired UTI in infants and children aged over 90 days up to 14 years. The current recommendations given by the American Academy of Pediatrics Practice guidelines, Canadian Pediatric Society guideline, and other international guidelines are considered as well as regional variations in susceptibility patterns and resources. This guideline covers the diagnosis, therapeutic options, and prophylaxis for the management of community-acquired UTI in children guided by our local antimicrobial resistance pattern of the most frequent urinary pathogens. Neonates, infants younger than three months, immunocompromised patients, children recurrent UTIs, or renal abnormalities should be managed individually because these patients may require more extensive investigation and more aggressive therapy and follow up, so it is considered out of the scope of these guidelines. Establishment of children-specific guidelines for the diagnosis and management of community-acquired UTI can reduce morbidity and mortality. We present a clinical statement from the Saudi Pediatric Infectious Diseases Society (SPIDS), which concerns the diagnosis and management of community-acquired UTI in children.

LncRNA Gas5 regulates Fn1 deposition via Creb5 in renal fibrosis

Aim: Although studies on lncRNAs in renal fibrosis have focused on target genes and functions of lncRNAs, a comprehensive interaction analysis of lncRNAs is lacking. Materials & methods: Differentially expressed genes in renal fibrosis were screened, and the interaction between lncRNAs and miRNAs was searched. Results: We constructed a ceRNA network associated with renal fibrosis, by which we found the transcription factor Creb5, a target gene of lncRNA Gas5 that might regulate extracellular Fn1 deposition. Conclusion: Our study not only provides a theoretical basis for the ceRNA regulation mechanism of Gas5 but also provides experimental evidence supporting the use of Gas5 targeting in the treatment of renal fibrosis.

Recurrent Febrile Urinary Tract Infections in a Five-Year-Old Girl

Urinary tract infections (UTIs) are one of the most common bacterial infections of childhood and in pediatric urology. Medical history, examination findings, and clinical course usually vary with the patient's age. Hence, there are no specific clinical features that are strictly associated with UTI in infants or children. This report presents a five-year-old female patient with spina bifida occulta and recurrent history of febrile UTIs diagnosed with detrusor sphincter dyssynergia over the last year. Urodynamic study confirmed an overactive uroflow pattern with bladder outlet obstruction (BOO) and high flow obstruction with long voiding time and terminal dribbling. The aim of this report is to showcase a typical presentation of secondary detrusor overactivity to bladder outlet obstruction in a patient with a coincidental finding of spina bifida occulta and to emphasize the importance of early treatment intervention in decreasing the risk of future complications such as UTIs.

Clinical Management of Children with a Congenital Solitary Functioning Kidney: Overview and Recommendations

CONTEXT

A congenital solitary functioning kidney (cSFK) is a common developmental defect that predisposes to hypertension and chronic kidney disease (CKD) as a consequence of hyperfiltration. Every urologist takes care of patients with a cSFK, since some will need lifelong urological care or will come with clinical problems or questions to an adult urologist later in life.

OBJECTIVE

We aim to provide clear recommendations for the initial clinical management and follow-up of children with a cSFK.

EVIDENCE ACQUISITION

PubMed and EMBASE were searched to identify relevant publications, which were combined with guidelines on related topics and expert opinion.

EVIDENCE SYNTHESIS

Initially, cSFK diagnosis should be confirmed and risk factors for kidney injury should be identified using ultrasound. Although more research into early predictors of kidney injury is needed, additional congenital anomalies of the kidney or urinary tract and absence of compensatory kidney hypertrophy have repeatedly been associated with a worse prognosis. The role of voiding cystourethrography and antibiotic prophylaxis remains controversial, and is complicated by the exclusion of children with a cSFK from studies. A yearly follow-up for signs of kidney injury is recommended for children with a cSFK. As masked hypertension is prevalent, annual ambulatory blood pressure measurement should be considered. During puberty, an increasing incidence of kidney injury is seen, indicating that long-term follow-up is necessary. If signs of kidney injury are present, angiotensin converting enzyme inhibitors are the first-line drugs of choice.

CONCLUSIONS

This overview points to the urological and medical clinical aspects and long-term care guidance for children with a cSFK, who are at risk of hypertension and CKD. Monitoring for signs of kidney injury is therefore recommended throughout life. Large, prospective studies with long-term follow-up of clearly defined cohorts are still needed to facilitate more risk-based and individualized clinical management.

PATIENT SUMMARY

Many children are born with only one functioning kidney, which could lead to kidney injury later in life. Therefore, a kidney ultrasound is made soon after birth, and other investigations may be needed as well. Urologists taking care of patients with a solitary functioning kidney should realize the long-term clinical aspects, which might need medical management.

The Rare Case of Perirenal Abscess in a Child-Possible Mechanisms and Methods of Treatment: A Case Report and Literature Review

Renal and perirenal abscesses are very rare in children. They can be present as an acute emergency condition or insidiously as a chronic disease. The diagnosis is not so obvious, and it is a big challenge, especially when it can simulate a kidney tumor. The treatment can be conservative, preferably with targeted antibiotics, or surgical, consisting primarily of drainage. This publication aims to present a clinical case in which both diagnosis and treatment were a big challenge for the entire treatment team. A 10-year-old male patient was admitted to the hospital because of mild abdominal pain and a temperature of 37.5 °C. The symptoms lasted for a week. In the computed tomography (CT), the lesion's dimensions were 11.1 × 8.2 × 25 cm, and inflammation, abscess, cyst, and abdominal tumor have been suggested. The decision about surgical treatment was made. An enormous abscess near the right kidney was localized. The patient's condition stabilized after surgery. Unfortunately, due to persistent purulent reservoirs, a second laparotomy was necessary. During the extensive diagnostic cystourethrography performed, vesicoureteral reflux was visualized. In conclusion, though a perinephric abscess is very rare in children, it should be taken into consideration in patients with non-specific abdominal symptoms. The imaging using ultrasound and CT scan with contrast enhancement is crucial to recognize and properly treat the condition. In terms of a small abscess, the only antimicrobial treatment using antibiotics of a broad spectrum can be considered. However, the drainage of an abscess, either percutaneous or open, should be used. For the large abscess, the open drainage seems to be a primary method of treatment. The importance of cooperation in a multidisciplinary team is crucial, as the diagnosis and treatment of underlying causes are essential.

Swiss consensus recommendations on urinary tract infections in children

The kidneys and the urinary tract are a common source of infection in children of all ages, especially infants and young children. The main risk factors for sequelae after urinary tract infections (UTI) are congenital anomalies of the kidney and urinary tract (CAKUT) and bladder-bowel dysfunction. UTI should be considered in every child with fever without a source. The differentiation between upper and lower UTI is crucial for appropriate management. Method of urine collection should be based on age and risk factors. The diagnosis of UTI requires urine analysis and significant growth of a pathogen in culture. Treatment of UTI should be based on practical considerations regarding age and presentation with adjustment of the initial antimicrobial treatment according to antimicrobial sensitivity testing. All children, regardless of age, should have an ultrasound of the urinary tract performed after pyelonephritis. In general, antibiotic prophylaxis is not recommended.Conclusion: Based on recent data and in line with international guidelines, multidisciplinary Swiss consensus recommendations were developed by members of Swiss pediatric infectious diseases, nephrology, and urology societies giving the clinician clear recommendations in regard to diagnosis, type and duration of therapy, antimicrobial treatment options, indication for imaging, and antibiotic prophylaxis. What is Known: • Urinary tract infections (UTI) are a common and important clinical problem in childhood. Although children with pyelonephritis tend to present with fever, it can be difficult on clinical grounds to distinguish cystitis from pyelonephritis, particularly in young children less than 2 years of age. • Method of urine collection is based on age and risk factors. The diagnosis of UTI requires urine analysis and significant growth of a pathogen in culture. What is New: • Vesicoureteric reflux (VUR) remains a risk factor for UTI but per se is neither necessary nor sufficient for the development of renal scars. Congenital anomalies of the kidney and urinary tract (CAKUT) and bladder-bowel dysfunction play a more important role as causes of long-term sequelae. In general, antibiotic prophylaxis is not recommended. • A switch to oral antibiotics should be considered already in young infants. Indications for invasive imaging are more restrictive and reserved for patients with abnormal renal ultrasound, complicated UTI, and infections with pathogens other than E. coli.

Management of Vesicoureteral Reflux: What Have We Learned Over the Last 20 Years?

Vesicoureteral reflux (VUR) is associated with increased risks of urinary tract infection, renal scarring and reflux nephropathy. We review advancements over the last two decades in our understanding and management of VUR. Over time, the condition may resolve spontaneously but it can persist for many years and bladder/bowel dysfunction is often involved. Some factors that increase the likelihood of persistence (e.g., high grade) also increase the risk of renal scarring. Voiding cystourethrography (VCUG) is generally considered the definitive method for diagnosing VUR, and helpful in determining the need for treatment. However, this procedure causes distress and radiation exposure. Therefore, strategies to reduce clinicians' reliance upon VCUG (e.g., after a VUR treatment procedure) have been developed. There are several options for managing patients with VUR. Observation is suitable only for patients at low risk of renal injury. Antibiotic prophylaxis can reduce the incidence of UTIs, but drawbacks such as antibiotic resistance and incomplete adherence mean that this option is not viable for long-term use. Long-term studies of endoscopic injection have helped us understand factors influencing use and the effectiveness of this procedure. Ureteral reimplantation is still performed commonly, and robot-assisted laparoscopic methods are gaining popularity. Over the last 20 years, there has been a shift toward more conservative management of VUR with an individualized, risk-based approach. For continued treatment improvement, better identification of children at risk of renal scarring, robust evidence regarding the available interventions, and an improved VUR grading system are needed.

Bladder/bowel dysfunction in pre-school children following febrile urinary tract infection in infancy

BACKGROUND

An association between bladder-bowel dysfunction (BBD) and urinary tract infection (UTI) is well-known. However, a question less explored is whether children with UTI early in life also have increased prevalence of BBD after they are toilet-trained. In this study, consecutively selected children with pyelonephritis during their first year of life were assessed for BBD at pre-school age.

METHODS

Ninety-two children (51 boys) hospitalized due to pyelonephritis during their first year of life were assessed for BBD at median age 5.4 years. A validated BBD questionnaire, along with urine flow and residual volume measurements, was used for diagnosing BBD. During follow-up, the group was well-characterized regarding renal status, vesicoureteral reflux (VUR), and recurrent UTI.

RESULTS

BBD was diagnosed in 35/92 (38%), of which the majority was sub-diagnosed with dysfunctional voiding (DV). There was a strong association between BBD and recurrent UTI during follow-up (p < 0.0001), but only a slight association with VUR status at presentation. Nevertheless, in the group with both BBD and VUR, recurrent UTI was four times higher (12/13, 92%) than in children who had neither VUR nor BBD (23%), (p = 0.0008). BBD was also associated with kidney damage (p = 0.017).

CONCLUSION

In children with pyelonephritis during the first year of life, 38% had BBD at pre-school age, regardless of whether they had VUR or not. The study shows an important association between BBD and recurrent UTI, so an assessment of BBD is therefore recommended for pre-school children with UTI, especially when they have history of pyelonephritis during infancy.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Immune Expression in Children With Vesicoureteral Reflux: A Pilot Study

OBJECTIVE

To perform an exploratory, descriptive pilot study of the systemic and local immune environment in patients with vesicoureteral reflux (VUR) and bladder-bowel dysfunction (BBD).

METHODS

Consecutive children with VUR undergoing intravesical ureteral reimplantation were enrolled. Patients were assessed for presence of BBD by reported patient history and validated questionnaire. Fresh blood and bladder tissue, collected at the time of surgery, were immediately processed for analysis. Immune cell compositions were determined via flow cytometry. Immune cell activation was also defined at the time of analysis. LegendPlex assay analysis was utilized to define levels of circulating chemokines and cytokines.

RESULTS

A total of 7 patients were enrolled. Although percentages of circulating immune cells in the blood of those with VUR/BBD and VUR alone were similar, within bladder tissue, VUR/BBD demonstrated increased immune infiltrates compared to VUR alone. Bladder sample analysis showed that B cells, and Effector Memory and Naïve T cell percentages were significantly increased in VUR/BBD patients compared to VUR patients. T cell expression of PD1 was increased in bladder tissues of BBD/VUR. Additionally, analysis of circulating neutrophils displayed significantly increased upregulation of PDL-1 in patients with VUR/BBD vs those with VUR only.

CONCLUSION

These pilot data suggest an immune-rich microenvironment is present within VUR. Severity of inflammation appeared to correlate with presence of BBD. This implies that targeting pelvic inflammation may be a novel therapy for children with VUR- or non-VUR-related BBD. Follow-up studies are currently underway.

Acute pyelonephritis in children and the risk of end-stage kidney disease

BACKGROUND

Pyelonephritis is the most common serious bacterial infection during childhood. The long-term importance of kidney scarring is unclear.

OBJECTIVE

To assess the risk of end-stage kidney disease (ESKD) in adolescents and young adults with history of pyelonephritis.

STUDY DESIGN

A nationwide, population-based, historical cohort study, including 1,509,902 persons (62% male) examined for military service between 1967 and 1997. Participants with a history of pyelonephritis were sub-grouped according to presence of kidney scarring and baseline kidney function. Data were linked to the Israeli ESKD registry to identify incident ESKD cases. Cox proportional hazards models were used to estimate the hazard ratio (HR) of treated ESKD (dialysis or kidney transplant).

RESULTS

Pyelonephritis was diagnosed in 6979 participants (0.46%). 6479 had normal kidney function and no evidence of kidney scarring, 400 had normal kidney function with evidence of scarring, and 100 demonstrated reduced baseline kidney function. Treated ESKD developed in 2352 individuals (0.2%) without history of pyelonephritis, 58 individuals (0.9%) with normal kidney function, history of pyelonephritis and no kidney scarring, 14 individuals (3.5%) with normal kidney function, history of pyelonephritis and kidney scarring, and 23 individuals (23.0%) with history of pyelonephritis and reduced baseline kidney function, yielding HR of 3.3, 34.8 and 43.2, respectively, controlling for age, gender, paternal origin, enrollment year, body mass index, and blood pressure, and accounting for death as a competing risk.

CONCLUSION

History of pyelonephritis was associated with significantly increased risk of treated ESKD, particularly when associated with kidney scarring or reduced baseline kidney function.

Antibiotic prophylaxis for prevention of urinary tract infections in the first year of life in children with vesicoureteral reflux diagnosed in the workup of antenatal hydronephrosis: a systematic review

BACKGROUND

Children with antenatal hydronephrosis (ANH) diagnosed with postnatal asymptomatic vesicoureteral reflux (VUR) are thought to be at higher risk of urinary tract infection (UTI). As such, continuous antibiotic prophylaxis (CAP) is empirically recommended until age of toilet training; however, there are limited data to support this. The objective of this systematic review was to summarize the existing data and compare UTI rates in infants with asymptomatic VUR on CAP during the first year of life, to those not on CAP. Secondary objectives were to determine associated risk factors with UTI development.

METHODS

A systematic search of all relevant studies and abstracts was conducted using 4 electronic databases by utilizing appropriate key words by an expert hospital librarian. Eligible studies included children with prenatal hydronephrosis, asymptomatic VUR with or without CAP, and reported on development of UTI in the first year.

RESULTS

Of 6903 citations screened, 18 were selected, giving a total population of 829 (69.4% male, median age 57 days) who met the inclusion criteria. Most studies were retrospective and of low-quality evidence. Overall, 15.4% of patients developed at least one breakthrough UTI and females had a higher risk of UTI (odds ratio (OR) 2.3, 95% CI 1.1-4.7). Comparison with children not taking CAP was not readily reported, and meta-analysis could not be completed.

CONCLUSIONS

Randomized controlled trials and standardized reporting of clinical variables are required to understand the protective effect of antibiotic prophylaxis in this cohort.

The role of bladder function in the pathogenesis and treatment of urinary tract infections in toilet-trained children

Urinary tract infections (UTIs) are a common reason for referral to pediatric specialists and the risk profile of these children is influenced by age, sex, and underlying urinary tract abnormalities. UTIs in toilet-trained children represent a different entity than confirmed, febrile UTIs that occur in infants, impacted by suboptimal bladder habits, bladder dysfunction, constipation, or a combination of these factors. A comprehensive literature search was conducted using PubMed and MEDLINE and search terms included recurrent UTI, VUR, bladder and bowel dysfunction (BBD), constipation, lower urinary tract symptoms, and voiding dysfunction. Common presenting symptoms of UTI in children include fever (> 38 °C) with or without "traditional" lower urinary tract symptoms (LUTS) such as dysuria, malodorous urine, frequency, urgency, and incontinence. However, many infections in older children are afebrile episodes-consisting primarily of LUTS-which may or may not be confirmed with biochemical and/or microbiological evidence. Therefore, when evaluating toilet-trained children with recurrent UTIs, it is paramount to consider dysfunctional elimination as an underlying cause, diagnose, and treat it prior to indicating surgical options, even in the presence of VUR or other anatomical abnormalities. Although the impact of bladder function on the risk of infections is important, so is the accurate diagnosis and initial evaluation. This review article will focus on an often overlooked yet critical factor: the impact of bladder function, particularly for toilet-trained children, as well as the importance of implementing bladder training strategies, aggressive management of constipation, and pharmacological management as necessary.

Current Management of Urinary Tract Infection and Vesicoureteral Reflux

Urinary tract infection (UTI) is defined as the growth of a significant number of microorganisms of a single species in the urine, in the presence of symptoms. Symptoms in young children are non-specific such as fever without focus; young infants may manifest with irritability, failure to thrive, jaundice, vomiting and diarrhea. Older children usually have symptoms of cystitis or pyelonephritis. Symptoms of cystitis are dysuria, frequency, new onset incontinence and malodorous urine while symptoms of pyelonephritis are high grade fever, flank pain and vomiting. Rapid urine testing by microscopy for pus cells, dipstick testing for leukocyte esterase and nitrite, and enhanced urinalysis are supportive tests. Urine culture samples should be collected with proper technique and results interpreted for significant growth accordingly. Antibiotic therapy for 7-14 d for complicated UTI and 3-4 d for uncomplicated UTI is adequate. Further evaluation is recommended clinically for bladder-bowel dysfunction and obvious anatomical defects and by imaging for vesicoureteral reflux (VUR), usually by micturating cystourethrography (MCU). Since MCU involves exposure to radiation and urethral catheterization, it is now reserved for children with parenchymal involvement or recurrent UTI. VUR is the backward flow of urine into one or both ureters. Clinical manifestations other than UTI include incidental diagnosis on antenatal ultrasonography. Reflux nephropathy, the renal scarring associated with VUR may manifest clinically as hypertension, proteinuria and renal failure. The management of VUR is primarily with antibiotic prophylaxis. Anatomical correction is indicated in case of breakthrough febrile UTI. No intervention has been shown to reduce renal scarring.

Analysis of drug resistance of extended-spectrum beta-lactamases-producing Escherichia coli and Klebsiella pneumoniae in children with urinary tract infection

Objectives:

To investigate the drug resistance of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K.pneumoniae) in children with urinary tract infection (UTI) and to provide the rationale for clinical use of antibiotics.

Methods:

This is a retrospective analysis of drug susceptibility in children with E. coli or K. pneumoniae-positive urine culture between August 2013 and August 2017, Shenzhen Children’s Hospital, Shenzhen, China. Drug resistance was statistically assessed using Fisher exact test and χ² test.

Results:

A total of 698 cases of E. coli, 426 of which were confirmed ESBL-producing strains, and 217 cases of K. pneumoniae, including 111 ESBL-producing strains, were detected, and the difference in proportion of positive ESBL-producing strains (61.03% versus 51.15%) was statistically significant (p=0.010). The average drug resistance rates of E. coli and K. pneumoniae to piperacillin/tazobactam, meropenem, ertapenem, imipenem, and amikacin were <15%. The average resistance rates of ESBL-producing E. coli and K. pneumoniae to cefpodoxime, cefixime, cefazolin, and ceftriaxone was >98%, while average resistance rates for non-ESBL-producing bacteria to the above 4 drugs was <20%.

Conclusion:

In southern China, the proportion of ESBL-producing strains and the drug resistance rates of E. coli and K. pneumoniae in UTI in children was high, but their resistance rates to carbapenems and β-lactamase inhibitor complexes containing tazobactam were low. Carbapenems are the most effective antibacterial drugs for the treatment of ESBL-producing bacteria.

Recurrent UTIs in Girls: What Is the Role of the Microbiome?

Urinary tract infections (UTIs) are one of the most common childhood bacterial infections. Recurrent UTIs can lead to renal scarring. Compared to boys, girls are more likely to develop scars as a result of recurrent UTIs. Therefore, there is a need to identify girls at high risk for recurrent UTIs and develop interventions to decrease the risk of recurrent UTIs. In this commentary, we will review the hypothesized pathophysiology of recurrent UTIs, explore the literature on the role of the microbiome in recurrent UTIs, focusing on female pediatric patients when able, and highlight the need for future research in this area.

Smell - Adding a New Dimension to Urinalysis

Background: Urinary tract infections (UTI) are among the most common infections in children. The primary tool to detect UTI is dipstick urinalysis; however, this has limited sensitivity and specificity. Therefore, urine culture has to be performed to confirm a UTI. Urinary volatile organic compounds (VOC) may serve as potential biomarker for diagnosing UTI. Previous studies on urinary VOCs focused on detection of UTI in a general population; therefore, this proof-of-principle study was set up in a clinical high-risk pediatric population. Methods: This study was performed at a tertiary nephro-urological clinic. Patients included were 0–18 years, clinically suspected of a UTI, and had abnormal urinalysis. Urine samples were divided into four groups, i.e., urine without bacterial growth, contamination, colonization, and UTI. VOC analysis was performed using an electronic nose (eNose) (Cyranose 320^®) and VOC profiles of subgroups were compared. Results: Urinary VOC analysis discriminated between UTI and non-UTI samples (AUC 0.70; p = 0.048; sensitivity 0.67, specificity 0.70). The diagnostic accuracy of VOCs improved when comparing urine without bacterial growth versus with UTI (AUC 0.80; p = 0.009, sensitivity 0.79, specificity 0.75). Conclusions: In an intention-to-diagnose high-risk pediatric population, UTI could be discriminated from non-UTI by VOC profiling, using an eNose. Since eNose can be used as bed-side test, these results suggest that urinary VOC analysis may serve as an adjuvant in the diagnostic work-up of UTI in children.

DCHS1 DNA copy number loss associated with pediatric urinary tract infection risk

Urinary tract infections (UTI), associated with vesicoureteral reflux (VUR), can lead to chronic kidney disease. Genetic alterations in the innate immune defenses contribute to UTI risk. We investigated a novel gene, Dachsous Cadherin-Related 1 (DCHS1), in children with UTI. We determined absolute DNA copy number (CN) of DCHS1 in children with UTI. In this case-control study, we utilized multiple complementary methods to determine the genomic CN of DCHS1. Children with (n = 370) and without (n = 71) VUR from two well-phenotyped clinical trials of UTI were copy-typed and compared to 491 healthy controls with no known history of VUR or UTI. Less than 1% of controls had a single copy of DCHS1, while 31% of children with UTI and no VUR and 7% of children with UTI and VUR had a single copy of the DCHS1 gene. Using immunostaining, we localized expression postnatally to the bladder and renal epithelia. Mice were also challenged with two uropathogenic Escherichia coli strains, and Dchs1 mRNA was quantified. This study represents the first report of DCHS1 in association with pediatric UTI. We hypothesize that its role in innate immunity is critical to lower urinary tract defense. Further investigation is required to determine the role of DCHS1 in innate immunity.

The pathogenesis and management of renal scarring in children with vesicoureteric reflux and pyelonephritis

Bacterial urinary tract infections (UTIs) are one of the most common reasons for children to be admitted to hospital. Bacteria infect and invade the bladder (the lower urinary tract) and if the infection disseminates to the upper urinary tract, significant inflammation in the kidneys may arise. Inflammation is a double-edged sword: it is needed to clear bacteria, but if excessive, kidney tissue is injured. During injury, nephrons are destroyed and replaced with deposition of extracellular matrix and a renal scar. In this review, we explore the pathogenesis of UTIs and discuss the risk factors that result in dissemination of bladder infection to the kidneys. Three major risk factors predispose to kidney infections: the presence of vesicoureteric reflux, the presence of bladder and bowel dysfunction, and defects in the ability of the host immune response to clear bacteria. In this review, we will discuss these factors, their relationship to renal scarring, and potential treatments that might be beneficial to prevent renal scar formation in children.

Updated Italian recommendations for the diagnosis, treatment and follow-up of the first febrile urinary tract infection in young children

AIM

Our aim was to update the recommendations for the diagnosis, treatment and follow-up of the first febrile urinary tract infection in young children, which were endorsed in 2012 by the Italian Society of Pediatric Nephrology.

METHODS

The Italian recommendations were revised on the basis of a review of the literature published from 2012 to October 2018. We also carried out an ad hoc evaluation of the risk factors to identify children with high-grade vesicoureteral reflux or renal scarring, which were published in the previous recommendations. When evidence was not available, the working group held extensive discussions, during various meetings and through email exchanges.

RESULTS

Four major modifications have been introduced. The method for collecting urine for culture and its interpretation has been re-evaluated. We have reformulated the algorithm that guides clinical decisions to proceed with voiding cystourethrography. The suggested antibiotics have been revised, and we have recommended further restrictions of the use of antibiotic prophylaxis.

CONCLUSION

These updated recommendations have now been endorsed by the Italian Society of Pediatric Nephrology and the Italian Society for Pediatric Infectivology. They can also be used to compare other recommendations that are available, as a worldwide consensus in this area is still lacking.

Bladder/bowel dysfunction at school age is seen in children with high-grade vesicoureteral reflux and lower urinary tract dysfunction in infancy

AIM

In approximately one third of cases, congenital high-grade vesicoureteral reflux (VUR) diagnosed during infancy is seen together with lower urinary tract dysfunction (LUTD), characterised by a high-capacity bladder and incomplete emptying. In an earlier study, 20 of these infants were treated with clean intermittent catheterisation during a 3-year period and with surgical treatment of the VUR before catheterisation was ended. In the present study, bladder function was evaluated in these children at school age.

METHODS

Bladder function was evaluated in the 20 children at a mean age of 7.3 years using a validated voiding-bowel questionnaire with scores (cut-off score 7) and a urine flow/residual study.

RESULTS

Four children (20%) had a normal voiding function at follow-up, whereas 11 (55%) had a clear bladder/bowel dysfunction (scores 7-19) and five (25%) had a mild dysfunction (score 6). Ten (63%) of the children with any dysfunction were recognised as dysfunctional voiding. Recurrent febrile urinary tract infections were correlated with the scores of faecal questions (P = .041), but for total scores P = .058.

CONCLUSION

The follow-up of bladder function in children at 7.3 years, diagnosed with high-grade VUR and LUTD in infancy, revealed bladder/bowel dysfunction of varying severity in the majority of cases.

Prevalence of Bladder and Bowel Dysfunction in Toilet-Trained Children With Urinary Tract Infection and/or Primary Vesicoureteral Reflux: A Systematic Review and Meta-Analysis

Introduction: Urinary tract infection (UTI) in children leads to renal scarring in 10-15% of patients. Urinary tract anomalies and bladder and bowel dysfunction (BBD) are documented risk factors for recurrent UTIs. Estimates of baseline prevalence of BBD in children with UTI will help the clinician in the management strategy. Hence, a systematic review and meta-analysis was conducted to estimate the pooled prevalence of BBD. Methods: MEDLINE, EMBASE, and CENTRAL (Cochrane Central Register of Controlled Trials) databases were searched for articles related to UTI, primary vesicoureteral reflux (VUR), and BBD. We included studies that provided prevalence of BBD in toilet-trained patients aged 1-18 years with UTI and/or VUR. BBD was defined based on clinical history or questionnaire or urodynamic studies. Two authors independently reviewed, assessed, and abstracted data from studies. Pooled prevalence was calculated based on a random effects model. Results: Forty-three studies fulfilling the eligibility criteria were selected from a total of 1,731 studies. Among patients presenting with UTI without primary VUR, pooled prevalence of BBD was 41% (95% CI: 26-55; nine studies, 920 patients, I ² = 96.0%), whereas its prevalence in patients with primary VUR was 49% (43-56; 30 studies, 5,060 patients, I ² = 96.0%). Weighting by the study design and quality did not affect the prevalence. In patients with primary VUR, prevalence of BBD was higher in females (53%; 42-65) than in males (44%; 15-73). In studies where urodynamic study was used for the diagnosis of BBD, prevalence was 63%. The presence of BBD in patients with primary VUR increased risk of recurrent UTIs [relative risk (RR): 2.1; 1.7-2.5]. In five studies that reported separate data on constipation, pooled prevalence of constipation was 27% (16-37). Conclusion: Almost half of the patients with primary VUR have BBD, and its presence increases the risk of recurrent UTIs. Trends of high BBD prevalence were also observed in patients presenting with UTI without VUR. These prevalence estimates suggest that all toilet-trained children presenting with UTI with or without VUR should be assessed for BBD, which will help in their further management.

Cost-Effectiveness of Screening Ultrasound after a First, Febrile Urinary Tract Infection in Children Age 2-24 Months

OBJECTIVE

To estimate the cost-effectiveness of routine, screening renal bladder ultrasound (RBUS) for children age 2-24 months after a first febrile urinary tract infection (UTI), as recommended by the American Academy of Pediatrics.

STUDY DESIGN

We developed a decision analytic model that simulates a population of children after a first febrile UTI. The model incorporates the diagnostic utility of RBUS to detect vesicoureteral reflux and genitourinary anomalies. We adopted a health-system perspective, 5-year horizon, and included 1-way and 2-way sensitivity analyses. Costs were inflated to 2018 US dollars, and our model incorporated a 3% discounting rate. We compared routine RBUS after first, febrile UTI compared with routine RBUS after second UTI (ie, control arm). Our main outcomes were recurrent UTI rate and incremental cost per quality-adjusted life-year (QALY).

RESULTS

Among children 2-24 months after a first febrile UTI, RBUS had an overall accuracy (true positives + true negatives) of 64.4%. The recurrent UTI rate in the intervention arm was 19.9% compared with 21.0% in the control arm. Thus, 91 patients would need to be screened with RBUS to prevent 1 recurrent UTI. RBUS increases QALYs by +0.0002 per patient screened, corresponding to an incremental cost-effectiveness ratio of $803 000/QALY gained. In the RBUS arm, 20.6% of children would receive unnecessary voiding cystourethrograms compared with 12.2% of children in the control group.

CONCLUSIONS

Screening RBUS after a first, febrile UTI in children age 2-24 months does not meet cost-effectiveness guidelines. Our findings support deferred screening until a second UTI.