Primary and acquired renal scarring in boys and girls with urinary tract infection

Abnormal Ultrasound Findings After a Urinary Tract Infection in Children

AIM

This study aimed to investigate the occurrence of urinary tract abnormalities detected in the ultrasound screening of children after a urinary tract infection episode, regardless of their age.

METHODS

This cohort study included children aged 0-16 years who underwent urinary tract ultrasound screening after a urinary tract infection between January 1, 2004, and December 31, 2015 in a paediatric university hospital in Finland. We excluded children with previously diagnosed pathologies of the urinary tract.

RESULTS

A total of 2050 children were included in this study. Among these, 116 (5.7%, 95% confidence interval 4.7%-6.7%) children had an abnormal ultrasound. In children with pyelonephritis, 70% of the abnormal ultrasounds were found in children younger than 2 years old. Age younger than 2 years was not associated with an increased risk of abnormality (odds ratio: 0.99, 95% confidence interval 0.65-1.52). Boys and children with non-Escherichia coli urinary tract infection or recurrent urinary tract infection were associated with a higher risk of having a urinary tract abnormality.

CONCLUSION

Limiting ultrasound screening after pyelonephritis to children under 2 years of age, as recommended in many current treatment guidelines, may miss a significant proportion (30%) of children with urinary tract abnormalities.

Analysis of the Distribution Characteristics and Changes of Drug Resistance of Pathogens in Patients with Urinary Tract Infection Across Southwest China From 2019 to 2023

Objective

To analyze the changes in the distribution and drug resistance of pathogenic bacteria causing urinary tract infections in Southwest China from 2019 to 2023, and to provide an accurate scientific basis for empirical clinical use.

Methods

The identification results and drug susceptibility tests of non-duplicate pathogens isolated from urine samples of patients in Sichuan region from 2019 to 2023 were retrospectively analyzed. The results obtained were interpreted with reference to CLSI M100-33th and analyzed with WHONET 5.6 software.

Results

A total of 247295 strains of pathogens were detected, including 188551 gram-negative strains (76.2%). The positive rate of female patients (56.8%) was significantly higher than that of male patients (43.2%). The top five most common urinary pathogens were Escherichia coli (50.5%), Enterococcus faecium (11.5%), Klebsiella pneumoniae (8.5%), Enterococcus faecalis (6.5%), and Proteus mirabilis (2.9%). The resistance rate of E.coli to levofloxacin, cefotaxime and ceftriaxone was higher (>50%) and had a certain upward trend. The resistance rates of Klebsiella pneumoniae to imipenem and meropenem increased from 7.8% and 9.6% in 2019 to 11.6% and 13.2% in 2023, respectively, much higher than the resistance rates of E. coli to carbapenem antibiotics (<2%). E. coli, K. pneumoniae and E. cloacae still maintained high activity against tigecycline and polymyxin B. The drug resistance rate of Acinetobacter baumannii to imipenem and meropenem was more than 27.4%. The resistance rates of Enterococcus faecium and Enterococcus faecalis to vancomycin, teicoplanin and linezolid were lower than 3.4%. There was an increasing trend in the detection of CRE-KPN among multidrug-resistant bacteria, and a slight decreasing trend in CRPA and CRAB.

Conclusion

The main pathogens of urinary tract infections were E. coli, E. faecium and K. pneumoniae. The drug resistance rates of main clinically isolated bacteria in urine samples showed a diverse trend. Antibiotics should be rationally selected based on the resistance patterns of the pathogens. At the same time, with the continuous detection of multi-drug resistant bacteria VRE and CRE, we have a long way to go in future drug resistance monitoring.

Urinary Tract Infection in Children: An Up-To-Date Study

Urinary tract infections (UTIs) are common bacterial infections in children. UTIs may be limited to the bladder or involve the kidneys with possible irreversible damage. Congenital abnormalities of the kidney and urinary tract (CAKUT) are often associated with UTIs; kidney scars have been considered a consequence of untreated UTIs but may be congenital. The mechanism by which bacteria produce inflammation in the urinary system has been intensively investigated. Diagnostic tools, including invasive imaging procedures, have been advocated in infants and small children with UTIs but are not necessary in most cases. Effective antibiotic drugs are available, and prophylactic treatment has been questioned. Several guidelines on UTIs are available, but a simple one for general practitioners is needed.

Impact of Urinary Tract Infection on Progression of Renal Scars and Formation of New Scars in Patients with Primary Vesicoureteric Reflux

INTRODUCTION

Primary vesicoureteric reflux (VUR) is a prevalent cause of end-stage renal failure in children. Scars on radionuclide imaging indicate irreparable damage to the growing kidneys. This study aims to determine whether a urinary tract infection (UTI) associated with primary VUR promotes the development of new renal scars or progression in the pre-existing ones.

MATERIALS AND METHODS

Children with primary VUR on continuous antibiotic prophylaxis at a tertiary teaching hospital's paediatric nephrourology clinic were observed prospectively. At recruitment, a renal cortical (dimercaptosuccinic acid [DMSA]) scan was done, and the children were followed up every 3 months. Breakthrough UTIs were documented, and follow-up DMSA scans were performed to document new scarring/grade advancement of existing scars in the renoureteric units (RUUs).

RESULTS

Seventy-two RUUs in 36 patients were monitored. Fifty-four (75%) RUUs were exposed to VUR of different grades, and 46 (85.1%) had a UTI. On the DMSA scan, these showed new scar development in 10/18 (55%) RUUs and scar progression in 13/28 (46.4%) RUUs. Of the 8 RUUs with VUR and without UTI, new scars manifest in 4/5 (80%) and progressed in 1/3 (33%). On univariate analysis, there was no significant difference in the formation of new scars or scar advancement on the DMSA scan between RUU with VUR and UTI and those without UTI. There was a significant positive correlation between the scarring on DMSA scan and the grade of reflux (P < 0.001).

CONCLUSION

Primary VUR patients had fresh or progressed scarring regardless of urinary infection. A higher VUR grade at presentation was a significant risk factor for scarring.

Pediatric urinary tract infections caused by poultry-associated Escherichia coli

Escherichia coli is the leading cause of urinary tract infections (UTIs) in children and adults. The gastrointestinal tract is the primary reservoir of uropathogenic E. coli, which can be acquired from a variety of environmental exposures, including retail meat. In the current study, we used a novel statistical-genomic approach to estimate the proportion of pediatric UTIs caused by foodborne zoonotic E. coli strains. E. coli urine isolates were collected from DC residents aged 2 months to 17 years from the Children's National Medical Center Laboratory, 2013-2014. During the same period, E. coli isolates were collected from retail poultry products purchased from 15 sites throughout DC. A total of 52 urine and 56 poultry isolates underwent whole-genome sequencing, core genome phylogenetic analysis, and host-origin prediction by a Bayesian latent class model that incorporated data on the presence of mobile genetic elements (MGEs) among E. coli isolates from multiple vertebrate hosts. A total of 56 multilocus sequence types were identified among the isolates. Five sequence types-ST10, ST38, ST69, ST117, and ST131-were observed among both urine and poultry isolates. Using the Bayesian latent class model, we estimated that 19% (10/52) of the clinical E. coli isolates in our population were foodborne zoonotic strains. These data suggest that a substantial portion of pediatric UTIs in the Washington DC region may be caused by E. coli strains originating in food animals and likely transmitted via contaminated poultry meat.IMPORTANCEEscherichia coli UTIs are a heavy public health burden and can have long-term negative health consequences for pediatric patients. E. coli has an extremely broad host range, including humans, chickens, turkeys, pigs, and cattle. E. coli derived from food animals is a frequent contaminant of retail meat products, but little is known about the risk these strains pose to pediatric populations. Quantifying the proportion of pediatric UTIs caused by food-animal-derived E. coli, characterizing the highest-risk strains, and identifying their primary reservoir species could inform novel intervention strategies to reduce UTI burden in this vulnerable population. Our results suggest that retail poultry meat may be an important vehicle for pediatric exposure to zoonotic E. coli strains capable of causing UTIs. Vaccinating poultry against the highest-risk strains could potentially reduce poultry colonization, poultry meat contamination, and downstream pediatric infections.

Imaging of Vesicoureteral Reflux: AJR Expert Panel Narrative Review

Vesicoureteral reflux (VUR) is a common congenital anomaly of the urinary tract that can present with collecting system dilation or as a febrile infection. VUR can lead to permanent renal sequelae requiring surgery but can also spontaneously resolve without complication. Therefore, recognizing patient populations who warrant imaging for screening, confirmation, or ongoing surveillance for VUR is important, as is avoiding overdiagnosis. In the appropriate patient populations, an accurate diagnosis of VUR allows early treatment and prevention of pyelonephritis and scarring. Various imaging modalities are available to diagnose and grade VUR, including voiding cystourethrography, radionucleotide cystography, and contrast-enhanced voiding urosonography (ceVUS). The objective of this article is to summarize the current understanding of VUR diagnosis and management and to discuss these imaging modalities' strengths and pitfalls. Considerations include indications for VUR imaging, patient preparation, conduct of the examination, issues related to radiologic reporting, and cost-effectiveness. An emphasis is placed on ceVUS, which is the most recently introduced of the three imaging modalities and is receiving growing support among pediatric radiologists.

Urinary Tract Infection Epidemiology in NICUs in the United States

OBJECTIVE

Our objective was to characterize the incidence, associated clinical factors, timing of infection, microbiology, and incidence of concordant blood culture of urinary tract infections (UTIs) in very low birth weight (VLBW <1,500g) infants.

STUDY DESIGN

Multicenter observational cohort study of VLBW infants with gestational age (GA) ≤32 weeks, still hospitalized on postnatal day 7, and discharged 2010 to 2018 from Pediatrix Medical Group neonatal intensive care units. Demographic and clinical characteristics of infants with and without UTI were compared. Multivariable logistic regression evaluated adjusted odds of UTI diagnosis.

RESULTS

Of 86,492 included infants, 5,988 (7%) had a UTI. The most common pathogen was Enterococcus spp. (20%), followed by Escherichia coli (19%) and Klebsiella spp. (18%). Candida spp. (6%) was the most common nonbacterial pathogen. Concordant-positive blood culture was present in 8% of infants with UTI diagnoses. UTI was associated with lower GA, male sex, vaginal delivery, prenatal steroid exposure, and longer duration of hospitalization.

CONCLUSION

UTI is a common cause of infection in VLBW infants, especially among the smallest, most premature, male infants, and those with a longer duration of hospitalization. Neonatal clinicians should consider obtaining urine culture in the setting of late-onset sepsis evaluations in VLBW infants.

KEY POINTS

· UTI is a common cause of LOS in VLBW infants.. · The most common pathogens are Enterococcus spp. and E. coli.. · UTI risk varies among different VLBW infant populations.. · Next steps should include evaluation of preventative measures..

Congenital anomalies of the kidney and urinary tract (CAKUT) in critically ill infants: a multicenter cohort study

BACKGROUND

The aim of the study was to determine the prevalence of congenital anomalies of the kidney and urinary tract (CAKUT) in the neonatal intensive care unit (NICU) and to evaluate risk factors associated with worse outcomes. We hypothesized that infants with CAKUT with extra-renal manifestations have higher mortality.

METHODS

This is a cohort study of all inborn infants who were diagnosed with any form of CAKUT discharged from NICUs managed by the Pediatrix Medical Group from 1997 to 2018. Logistic and linear regression models were used to analyze risk factors associated with in-hospital mortality.

RESULTS

The prevalence of CAKUT was 1.5% among infants hospitalized in 419 NICUs. Among the 13,383 infants with CAKUT analyzed, median gestational age was 35 (interquartile range [IQR] 31-38) weeks and median birth weight was 2.34 (IQR 1.54-3.08) kg. Overall in-hospital mortality for infants with CAKUT was 6.8%. Oligohydramnios (adjusted odds ratio [aOR] 4.5, 95% confidence interval [CI] 2.2-9.1, p < 0.001), extra-renal anomalies (aOR 2.5, 95% CI 2.0-3.1, p < 0.001), peak SCr (aOR 1.02, 95% CI 1.01-1.03, p < 0.001) and exposure to nephrotoxic medications (aOR 1.4, 95% CI 1.1-1.7, p = 0.01) were associated with increased mortality, while a history of urological surgery or intervention was associated with lower mortality (aOR 0.6, 95% CI 0.4-0.7, p < 0.001).

CONCLUSIONS

Infants hospitalized in the NICU who have CAKUT and the independent risk factors for mortality (e.g., oligohydramnios and presence of extra-renal anomalies) require close monitoring, minimizing of exposure to nephrotoxic drugs, and timely urological surgery or intervention. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

Primary Vesicoureteral Reflux and Renal Scarring

Vesicoureteral reflux (VUR) is the commonest congenital anomaly of urinary tract in children. It is mostly diagnosed after a urinary tract infection or during evaluation for congenital anomalies of the kidney and urinary tract. High-grade VUR, recurrent pyelonephritis, and delayed initiation of antibiotic treatment are important risk factors for renal scarring. The management of VUR depends on multiple factors and may include surveillance only or antimicrobial prophylaxis; very few patients with VUR need surgical correction. Patients with renal scarring should be monitored for hypertension and those with significant scarring should also be monitored for proteinuria and chronic kidney disease.

Whole exome sequencing identifies KIF26B, LIFR and LAMC1 mutations in familial vesicoureteral reflux

Vesicoureteral reflux (VUR) is a common urological problem in children and its hereditary nature is well recognised. However, despite decades of research, the aetiological factors are poorly understood and the genetic background has been elucidated in only a minority of cases. To explore the molecular aetiology of primary hereditary VUR, we performed whole-exome sequencing in 13 large families with at least three affected cases. A large proportion of our study cohort had congenital renal hypodysplasia in addition to VUR. This high-throughput screening revealed 23 deleterious heterozygous variants in 19 candidate genes associated with VUR or nephrogenesis. Sanger sequencing and segregation analysis in the entire families confirmed the following findings in three genes in three families: frameshift LAMC1 variant and missense variants of KIF26B and LIFR genes. Rare variants were also found in SALL1, ROBO2 and UPK3A. These gene variants were present in individual cases but did not segregate with disease in families. In all, we demonstrate a likely causal gene variant in 23% of the families. Whole-exome sequencing technology in combination with a segregation study of the whole family is a useful tool when it comes to understanding pathogenesis and improving molecular diagnostics of this highly heterogeneous malformation.

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.

Clinical guidelines of UTIs in children: quality appraisal with AGREE II and recommendations analysis

OBJECTIVE

To explore the current Chinese and English guidelines of urinary tract infection (UTI) in children and provide a summary of the recommendations of the guidelines.

METHODS

An electronic search was conducted on databases, including Pubmed, SinoMed, Wangfang Data, CHKD,VIP, NICE, WHO, GIN and Medliveto retrieve data of the clinical practice guidelines on UTI from the establishment of the database to June 2020. Four assessors assessed the quality of guidelines using the Appraisal of Guidelines for Research & Evaluation II (AGREE II) and evaluated the specific recommendations in guidelines.

RESULTS

(1) Nine guidelines including two from the USA (AAP and A guideline for the inpatient care of children with pyelonephritis) and the remaining from EAU/ESPU, SINEPE, KHA-CARI, CPS, ISPN, NICE and CMA-CSP were explored. (2) The AGREE II evaluation demonstrated higher scores of UTI guidelines in terms of 'scope and purpose' (72.99%±11.19%) and 'clarity of presentation' (75.62%±7.75%), whereas the average scores were lower in the aspect of 'stakeholder involvement' (35.49%±14.41%), 'rigour of development' (37.05%±10.05%), 'applicability' (37.75%±11.98%) and 'editorial independence' (43.06%±48.14%). The average scores of the guidelines were as follows: SINePe (72.57%), CMA-CSP (62.96%), EAU/ESPU (59.61%), AAP (56.86%), NICE (47.54%), CPS (40.93%), KHA-CARI (38.86%), ISPN (38.63%) and A guideline for the inpatient care of children with pyelonephritis (34.72%). (3) All the selected guidelines basically reached a consensus on urine sample retention methods in older children, the antibiotic treatment course and renal and bladder ultrasonography application but lacked a conclusion on the determination of urine culture results, the choice of voiding cystourethrography and Tc-99mdimercaptosuccinicacid, and antibiotic prophylaxis.

CONCLUSION

There remains a need to improve the quality of guidelinesfor UTI in clinical practice. Existing controversies on the current guidelines of UTI in some recommendations warrant further exploration to provide more evidence on formulating more unified and practical guidelines in the future.

ETHICS AND DISSEMINATION

No ethical approval is required for this research, as it did not include patients or patient data.

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.

Bacterial and Fungal Profile, Antibiotic Susceptibility Patterns of Bacterial Pathogens and Associated Risk Factors of Urinary Tract Infection Among Symptomatic Pediatrics Patients Attending St. Paul’s Hospital Millennium Medical College: A Cross-Sectional Study

Background

Urinary tract infection is a common infection in pediatrics. Understanding the common etiology of urinary tract infections, their antimicrobial susceptibility pattern, and associated risk factors in a particular setting can provide evidence for the appropriate treatment of the cases.

Purpose

The current study is aimed to determine the common etiology and prevalence of uropathogens associated with urinary tract infection, as well as the antibiotic susceptibility profile of bacterial isolates, and to identify risk factors associated with urinary tract infection among pediatric patients.

Materials and Methods

The study was conducted at St. Paul Hospital Millennium Medical College between October 2019 and July 2020. Urine was collected aseptically from patients, inoculated onto culture media, and incubated at 37 °C for 18–48 hours. Bacteria and yeast were identified following standard procedures. Antibiotic susceptibility testing of bacterial pathogens was carried out by the Kirby Bauer disc diffusion method. Descriptive statistics and logistical regressions were used to estimate the crude ratio with a 95% confidence interval. P-value < 0.05 was considered significant.

Results

Significant bacterial/fungal growth was observed in 65 samples giving a prevalence of 28.6% of which 75.4% (49/65) and 24.6% (16/65) were bacterial and fungal pathogens, respectively. About 79.6% of bacterial etiology were Escherichia coli and Klebsiella pneumoniae. The highest resistance was observed against ampicillin (100%), cefazolin (92.1%), and trimethoprim-sulfamethoxazole (84.1%), both of which are commonly used for empirical treatment in Ethiopia. Length of hospital stay (P=0.01) and catheterization (P=0.04) were statistically associated with urinary tract infection.

Conclusion

The high prevalence of urinary tract infection was observed in our study. Enterobacteriaceae were the major cause of urinary tract infection. Length of hospital stay and catheterization were significantly associated with urinary tract infection. Both Gram-negative and Gram-positive bacteria were extremely resistant to ampicillin and trimethoprim-sulfamethoxazole.

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 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.

How Swedish guidelines on urinary tract infections in children compare to Canadian, American and European guidelines

Urinary tract infections (UTI) are common in children and the guidelines focus on preventing kidney damage. We compared the 2013 national Swedish guidelines on UTIs in children with the guidelines from America, Canada, UK, Spain, Italy and European urologists. This showed that urinalysis and urine cultures are endorsed by all the guidelines, but sampling techniques and bacteria levels differ. They all recommend initial oral treatment and renal ultrasound to detect major anomalies in infants. The Swedish guidelines are more liberal on antibiotic prophylaxis. CONCLUSION: Differences in diagnostic criteria, workup and accepted methods for urine sampling were noted and are discussed.

Types of Parenchymal Changes Diagnosed on DMSA Scans of Kidneys Affected by Different Grades of Vesicoureteral Reflux

Background

Renal parenchymal damage and scarring usually is associated with urinary tract infection (UTI), whereas the impact of vesicoureteral reflux (VUR) on the kidneys is unclear. We aimed to compare kidneys with all grades of VUR (grades Io-V) and those without VUR by using direct radionuclide cystography, voiding cystourethrography, and findings from ^99mTc-DMSA scintigraphy (DMSA scan).

Material/Methods

The present analysis included 253 renal ureteral units (RUU) from 129 children with VUR and recurrent UTI and children with a single febrile UTI associated with abnormal ultrasonographic findings. The 6 grades of VUR (Io, I, II, III, IV, and V) and 35 RUUs without VUR were divided into 4 groups: 1. Non-dilated VUR (grades Io-II); 2. Mildly dilated VUR (grade III); 3. Dilated VUR (grades IV–V); and 4. The control group.

Results

DMSA scanning showed significant differences between the groups with non-dilated VUR, grade III VUR, grades IV–V VUR, and the control group in kidney width (χ²=30.5; P<0.001); position and shape (χ²=30.6; P<0.001); intensity of activity (χ²=38.1; P<0.001); distribution of activity (χ²=34.5; P<0.001); and existence of scars (χ²=16; P<0.001). The probability of abnormalities on DMSA scans increased with the VUR grade. However, inside the groups of dilated and non-dilated VUR we found no significant statistical differences between those characteristics.

Conclusions

Our results indicate that kidneys without VUR or with non-dilated lateral VUR and dilated VUR on the contralateral side represent 2 different categories of parenchymal changes.

Urine neutrophil gelatinase-associated lipocalin in girls with recurrent urinary tract infections

BACKGROUND

Children who experience more than one urinary tract infection (UTI) are at increased risk of kidney scarring due to their UTIs. Girls are at especially high risk for developing kidney scarring as a result of recurrent UTIs. Prior work suggested that neutrophil gelatinase-associated lipocalin (NGAL) may be lower in children with recurrent UTI compared with those without. The objective of this work was to compare urine NGAL concentrations in matched urine samples in girls with single and recurrent UTIs.

METHODS

Girls less than 6 years of age who presented with signs and symptoms of a UTI were eligible for enrollment. Both acute, obtained from residual urine collected as part of their clinical evaluation, and follow-up urine samples, obtained after the completion of antibiotics when the patient was in their usual state of health, were collected from patients. Acute and follow-up urine NGAL concentrations were compared between girls with single and recurrent UTIs, as well as those with negative cultures who served as controls.

RESULTS

Seventy girls were included in this study, 6 controls, 43 single UTIs, and 20 girls with recurrent UTIs. Patients in the control group had lower median acute NGAL concentrations than either those with single or recurrent UTI. There were no differences in either acute or follow-up urine NGAL concentrations between those with single and recurrent UTIs.

CONCLUSION

In this cohort of girls less than 6 years of age, there is no difference in urine NGAL concentrations between those with single and recurrent UTIs.

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.

Kidney structure and function in dilating vesicoureteral reflux patients with anorectal malformation

Background

We assessed the impact of anorectal malformation (ARM) on the kidneys of children with dilating vesicoureteral reflux (D-VUR) ≥grade III using a simple dimercaptosuccinic acid (DMSA) scintigraphy scan based renal dysfunction score (RDS).

Methods

The medical records of 121 patients with D-VUR treated between 2000 and 2014 were reviewed retrospectively. After excluding patients with secondary D-VUR (n=18), presence of ARM was used to create two groups: ARM+ (n=12 cases; 15 ureters) and ARM– (n=91 cases; 131 ureters). Types of ARM, grades of D-VUR, bladder and bowel dysfunction (BBD) and RDS were compared.

Results

Patient demographics, mean follow-up, grades of D-VUR and history of urinary tract infections were not significantly different. BBD was significantly higher in ARM+ (41.7% versus 7.7%, p=0.0006). RDS was significantly higher in ARM+ (p=0.036). Grades of D-VUR were significantly lower in ARM– with low RDS (p=0.008). During follow-up, changes in DMSA uptake over time were not observed in ARM+.

Conclusions

While renal cortical lesions were correlated with grade of D-VUR in ARM– and RDS was significantly higher in ARM+, BBD did not appear to contribute to progressive renal dysfunction as is commonly believed. In fact, no progression in renal cortical lesions was observed in ARM+ based on RDS data. Renal cortical lesions may possibly be a feature of ARM, a topic that warrants further study.

Developmental loss, but not pharmacological suppression, of renal carbonic anhydrase 2 results in pyelonephritis susceptibility

Carbonic anhydrase II knockout (Car2^-/-) mice have depleted numbers of renal intercalated cells, which are increasingly recognized to be innate immune effectors. We compared pyelonephritis susceptibility following reciprocal renal transplantations between Car2^-/- and wild-type mice. We examined the effect of pharmacological CA suppression using acetazolamide in an experimental murine model of urinary tract infection. Car2^-/- versus wild-type mice were compared for differences in renal innate immunity. In our transplant scheme, mice lacking CA-II in the kidney had increased pyelonephritis risk. Mice treated with acetazolamide had lower kidney bacterial burdens at 6 h postinfection, which appeared to be due to tubular flow from diuresis because comparable results were obtained when furosemide was substituted for acetazolamide. Isolated Car2^-/- kidney cells enriched for intercalated cells demonstrated altered intercalated cell innate immune gene expression, notably increased calgizzarin and insulin receptor expression. Intercalated cell number and function along with renal tubular flow are determinants of pyelonephritis risk.

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.

Urinary tract infection in pediatrics: an overview

OBJECTIVE

This review aimed to provide a critical overview on the pathogenesis, clinical findings, diagnosis, imaging investigation, treatment, chemoprophylaxis, and complications of urinary tract infection in pediatric patients.

SOURCE OF DATA

Data were obtained independently by two authors, who carried out a comprehensive and non-systematic search in public databases.

SUMMARY OF FINDINGS

Urinary tract infection is the most common bacterial infection in children. Urinary tract infection in pediatric patients can be the early clinical manifestation of congenital anomalies of the kidney and urinary tract (CAKUT) or be related to bladder dysfunctions. E. coli is responsible for 80-90% of community-acquired acute pyelonephritis episodes, especially in children. Bacterial virulence factors and the innate host immune systems may contribute to the occurrence and severity of urinary tract infection. The clinical presentation of urinary tract infections in children is highly heterogeneous, with symptoms that can be quite obscure. Urine culture is still the gold standard for diagnosing urinary tract infection and methods of urine collection in individual centers should be determined based on the accuracy of voided specimens. The debate on the ideal imaging protocol is still ongoing and there is tendency of less use of prophylaxis. Alternative measures and management of risk factors for recurrent urinary tract infection should be emphasized. However, in selected patients, prophylaxis can protect from recurrent urinary tract infection and long-term consequences. According to population-based studies, hypertension and chronic kidney disease are rarely associated with urinary tract infection.

CONCLUSION

Many aspects regarding urinary tract infection in children are still matters of debate, especially imaging investigation and indication of antibiotic prophylaxis. Further longitudinal studies are needed to establish tailored approach of urinary tract infection in childhood.

The prevalence of kidney scarring due to urinary tract infection in Iranian children: a systematic review and meta-analysis

INTRODUCTION

Urinary tract infection is one of the most common diseases in childhood, and can lead to severe complications such as renal scarring in case of lack of diagnosis and timely treatment.

OBJECTIVE

The aim of this study was to investigate the prevalence of kidney scarring caused by urinary tract infection in Iranian children by meta-analysis.

STUDY DESIGN

English -language databases including Science Direct, PubMed, Scopus, Web of Science, and Springer, and Persian -language sites including SID, Magiran, Iranmedex, and Medlib, and the Google Scholar search engine were searched by in March 2018 using MeSH keywords. The heterogeneity of studies was studied using the I2 index. Data were analyzed using STATA software, version 15.1.

RESULTS

In 18 studies, the prevalence of kidney scarring from urinary tract infections in Iranian children was 31% (95% confidence intervalCI: 22%-39%), (which was 14% in girls and 23% in boys. Also, the prevalence of kidney scar in children with urinary reflux was 47% and in children without urinary reflux was 12%. The most common symptom of the renal scar was fever in 61%, followed by urinary reflux in 45% (unilateral in 42% and bilateral in 30%). Also, the prevalence of mild, moderate, and severe reflux, respectively, was 31%, 27%, and 13%. Meta-regression also showed that the prevalence of kidney scar due to urinary tract infections had no significant relationship with the number of samples and years of research (P > 0.05).

DISCUSSION AND CONCLUSION

About one-third of Iranian children suffering from urinary tract infections had kidney scarring, so that the prevalence is lower in girls than in boys. Also, the prevalence of renal scarring in children with urinary reflux is about four times higher than that in children without urinary reflux.

ACR Appropriateness Criteria® Urinary Tract Infection-Child

Urinary tract infection (UTI) is common in young children and may cause pyelonephritis and renal scarring. Long-term complications from renal scarring are low. The role of imaging is to evaluate for underlying urologic abnormalities and guide treatment. In neonates there is increased risk for underlying urologic abnormalities. Evaluation for vesicoureteral reflux (VUR) may be appropriate especially in boys because of higher prevalence of VUR and to exclude posterior urethral valve. In children older than 2 months with first episode of uncomplicated UTI, there is no clear benefit of prophylactic antibiotic. Ultrasound is the only study that is usually appropriate. After the age of 6 years, UTIs are infrequent. There is no need for routine imaging as VUR is less common. In children with recurrent or complicated UTI, in addition to ultrasound, imaging of VUR is usually appropriate. Renal cortical scintigraphy may be appropriate in children with VUR, as renal scarring may support surgical intervention. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Urinary tract infection in children: Diagnosis, treatment, imaging - Comparison of current guidelines

BACKGROUND AND OBJECTIVE

Urinary tract infection (UTI) is a frequent disorder of childhood, yet the proper approach for a child with UTI is still a matter of controversy. The objective of this study was to critically compare current guidelines for the diagnosis and management of UTI in children, in light of new scientific data.

METHODS

An analysis was performed of the guidelines from: American Academy of Pediatrics (AAP), National Institute for Health and Care Excellence (NICE), Italian Society of Pediatric Nephrology, Canadian Paediatric Society (CPS), Polish Society of Pediatric Nephrology, and European Association of Urology (EAU)/European Society for Pediatric Urology (ESPU). Separate aspects of the approach for a child with UTI, including diagnosis, treatment and further imaging studies, were compared, with allowance for recent research in each field.

CONCLUSIONS

The analyzed guidelines tried to reconcile recent reports about diagnosis, treatment, and further diagnostics in pediatric UTI with prior practices and opinions, and economic capabilities. There was still a lack of sufficient data to formulate coherent, unequivocal guidelines on UTI management in children, with imaging tests remaining the main area of controversy. As a result, the authors formulated their own proposal for UTI management in children.

Vesicoureteral reflux and continuous prophylactic antibiotics

Vesicoureteral reflux (VUR) management must be tailored based on the risk for further infections and renal scarring, gender, likelihood of spontaneous resolution, and parental preferences. Because we now understand that sterile VUR is benign and most reflux spontaneously resolves over time, the initial approach in majority of children is non-surgical with continuous antibiotic prophylaxis (CAP) and correction of bladder and bowel dysfunction. Despite increasing utilization of CAP over the past four decades, the efficacy of antibiotic prophylaxis has been questioned due to conflicting results of studies plagued with design flaws and inadequate subject sample size. The Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) trial, which was designed to address many of the limitations from previous studies, provided much needed answers. In this review, we sought to describe the controversy surrounding VUR management, highlight the results of RIVUR trial, and discuss how the RIVUR findings impact our understanding of CAP in the management of VUR.

The Swedish infant high-grade reflux trial: UTI and renal damage

INTRODUCTION

High-grade vesicoureteral reflux (VUR) in children is associated with recurrent urinary tract infection (UTI) and renal damage. Breakthrough UTI despite continuous antibiotic prophylaxis (CAP) during the first years of life is a matter of concern and evokes early intervention. We investigated whether early endoscopic treatment (ET) of VUR grade 4-5 can reduce the risk of UTI recurrence and renal scarring.

MATERIALS AND METHODS

This prospective, randomized, controlled, multicentre, 1-year follow-up trial comprised 77 infants, <8 months of age with VUR grade 4-5 (Table) randomized to CAP (n = 39) or ET (with prophylaxis until resolution) (n = 38). Voiding cystourethrogram, ultrasound, renal scintigraphy, and free voiding observation were performed at study entry and after 1 year. Parenchymal defects were seen in 67 (87%) children at entry, 39 (34 boys, 5 girls) of them characterized as generalized. At follow-up, renal deterioration (new scars or progress in old damaged area) and symptomatic UTIs were reported.

RESULTS

There were 27 recurrent febrile UTIs in 6 (16%) children in the ET group and in 10 (26%) in the CAP group (p = 0.43), in eight (36%) girls and eight (15%) boys (p = 0.039). Successful VUR outcome (VUR 0-2) was seen in 22 (59%) in the ET and eight (21%) in the CAP group (p = 0.0014). Multiple recurrences were only seen in patients with persistent dilating reflux at follow-up (p = 0.019). Deterioration on scintigraphy was seen in eight children (9 kidneys) with no difference between treatment groups (p = 0.48) or sex (p = 0.17). Renal deterioration was associated with high bladder capacity (BC) and large residual volume (PVR) at 1 year (p = 0.0092 and p = 0.041). Six of the eight children with renal deterioration had a recurrent UTI (p = 0.0032). Seven of nine renal units with deterioration were seen in children with persistent VUR 3-5 at follow-up. Univariable logistic regression identified female sex and high PVR as positive predictors for recurrent UTI (p = 0.039 and 0.034) and high PVR tended to predict renal deterioration (p = 0.053).

DISCUSSION

No differences between the treatment groups regarding recurrent UTI and renal deterioration could be found. Increased PVR and female sex were positive predictors for UTI recurrences. VUR grade at follow-up was correlated to UTI recurrence and renal deterioration.

CONCLUSION

This study did not show any difference between ET and CAP in reducing the risk of UTI recurrence or renal deterioration. The rate of VUR resolution was higher in the ET group and VUR grade at follow-up correlated with both UTI recurrence and renal deterioration.

Urinary tract infection in small children: the evolution of renal damage over time

BACKGROUND

Our objective was to analyze the evolution of kidney damage over time in small children with urinary tract infection (UTI) and factors associated with progression of renal damage.

METHODS

From a cohort of 1003 children <2 years of age with first-time UTI, a retrospective analysis of 103 children was done. Children were selected because of renal damage at index ^99mTc-dimercaptosuccinic acid (DMSA) scintigraphy at least 3 months after UTI, and a late DMSA scan was performed after at least 2 years. Damage was classified as progression when there was a decline in differential renal function (DRF) by ≥4%, as regression when there was complete or partial resolution of uptake defects.

RESULTS

Of 103 children, 20 showed progression, 20 regression, and 63 remained unchanged. There were no differences between groups regarding gender or age. In the progression group, 16/20 (80%) children had vesicoureteral reflux (VUR) grade III-V and 13 (65%) had recurrent UTI. In multivariable regression analysis, both VUR grade III-V and recurrent UTI were associated with progression. In the regression group, 16/20 (80%) had no VUR or grade I-II, and two (10%) had recurrent UTI.

CONCLUSIONS

Most small children with febrile UTI do not develop renal damage and if they do the majority remain unchanged or regress over time. However, up to one-fifth of children with renal damage diagnosed after UTI are at risk of renal deterioration. These children are characterized by the presence of VUR grades III-V and recurrent febrile UTI and may benefit from follow-up.

Incidence of Breakthrough Urinary Tract Infection in Hospitalized Infants Receiving Antibiotic Prophylaxis

Urinary tract infections (UTIs) are a source of substantial morbidity in children in the neonatal intensive care unit. The incidence of UTIs that occur in critically ill infants during a course of antibiotic prophylaxis (i.e., breakthrough urinary tract infections [BUTIs]) is not known. We investigated the incidence of BUTI in a cohort of infants hospitalized on prophylactic antibiotics in neonatal intensive care units. Predictors of BUTI were evaluated using multivariable Cox regression. Out of 716 787 infants, 631 (0.09%) were prescribed 821 courses of antibiotic prophylaxis. Among this cohort, 60 infants (9.5%) suffered a total of 65 BUTIs. Of all prophylactic antibiotic courses, 65/821 (7.9%) were complicated by BUTI. Klebsiella, Enterobacter, and Escherichia coli species were the most common causes of BUTI. There was no statistically significant difference ( P = .78) in BUTI incidence among the 4 antibiotics assessed (amoxicillin, cephalexin, nitrofurantoin, or trimethoprim-sulfamethoxazole).

Delayed treatment of the first febrile urinary tract infection in early childhood increased the risk of renal scarring

AIM

This study evaluated the controversial relationship between the duration of fever before treatment initiation (FBT) for a febrile urinary tract infection (UTI), with renal scarring based on dimercaptosuccinic acid scintigraphy (DMSA) findings.

METHODS

The inpatient records of 148 children under two years of age with a first episode of febrile UTI were analysed. Acute and repeat DMSA findings, and clinical and laboratory parameters were evaluated.

RESULTS

Acute DMSA showed that 76 of the 148 children with a febrile UTI had renal lesions: 20 were mild, and 56 were moderate or severe. Repeat DMSA showed renal scarring in 34 patients. The only factors associated with the development of renal scars in the repeat DMSA were FBT of more than 72 hours, the presence and severity of vesicoureteral reflux and increased procalcitonin levels and absolute neutrophil counts. Multiple regression analysis showed that an FBT above 72 hours was the only significant factor that predicted renal scars.

CONCLUSION

Delay in treatment initiation of 72 hours or more was a risk factor for permanent renal scars after the first episode of febrile UTI. Other associated factors were increased procalcitonin and absolute neutrophil count on admission and the presence and severity of vesicouretal reflux.

Association between clean intermittent catheterization and urinary tract infection in infants and toddlers with spina bifida

INTRODUCTION

The primary goal of urologic management in children with spina bifida is to reduce the risk of urinary tract infection (UTI) and associated renal injury. While clean intermittent catheterization (CIC) has been the mainstay of treatment, recent studies have suggested that this approach is not without risk. The objective of this study was to examine the association between alternative bladder management strategies and UTI in infants and toddlers with spina bifida.

METHODS

A retrospective cohort study was conducted on spina bifida patients, aged 0-3 years, seen in a multidisciplinary spinal defects clinic between 2008 and 2013. Inclusion criteria included: a primary diagnosis of meningocele, myelomeningocele, or lipomyelomeningocele. Patients were excluded if they had: <1 year of follow-up, urologic surgery prior to initial evaluation, or incomplete data for analysis. Bivariate analyses were performed using Chi-squared or Fisher's exact tests. Multivariate analyses were performed using logistic regression.

RESULTS

A total of 107 patients meeting study criteria were identified. The majority of patients had lumbar lesions (74.8%) and ventriculoperitoneal (VP) shunts (72.9%). Initial bladder management was by CIC in 39.3% of patients and spontaneous voiding in 60.8% of patients. Median age at follow-up was 2.5 years. During the study period, 23.4% of patients switched from spontaneous voiding to CIC. Patients managed with CIC were more likely to have UTIs at final follow-up than those managed with voiding (35.7% vs. 18.5%; P = 0.045). Patients with vesicoureteral reflux (VUR) were also more likely to have UTIs (54.5% vs. 17.9%; P = 0.015). Patients who switched from spontaneous voiding to CIC over the study period were more likely to be evaluated with urodynamics (72.0% vs. 31.8%; P < 0.0001) than those managed with voiding alone. Patients who switched to CIC were also more likely to have VUR (16% vs. 0%; P = 0.09) and UTIs (24% vs. 15%; P = 0.06) than those managed with voiding alone; however, these differences were not statistically significant.

CONCLUSIONS

In the present series, infants and toddlers with spina bifida who were initially managed with spontaneous voiding had a lower risk of UTI than those managed with CIC. Patients who switched to CIC after a period of initial observation with voiding did not have a significantly different risk of UTI compared with those managed with CIC alone. These findings suggest that early initiation of CIC may not be warranted in all infants with spina bifida. Further studies are needed to more clearly define optimal indications for initiation of CIC in these patients.

Clinical characteristics and prevalence of complications of chronic kidney disease in children: the Taiwan Pediatric Renal Collaborative study

BACKGROUND

Little information is available regarding the clinical characteristics and prevalence of complications in children with chronic kidney disease (CKD), especially in early disease stages. The objective of this study was to determine the clinical characteristics and prevalence of complications in children with predialytic CKD.

METHODS

This multicenter, cross-sectional study enrolled children at all stages of predialytic CKD. Children who were between the ages of 1 year and 18 years and who fulfilled the clinical criteria of CKD were included in the study. Baseline demographic data, previous history, clinical characteristics, and laboratory data were collected.

RESULTS

A total of 757 children were included in the study. The median age at the time of enrollment was 10.6 years; 397 patients (52.4 %) were males. A total of 39.0 % of the patients were in CKD stage 1, 37.6 % were in stage 2, 14.8 % were in stage 3, 3.0 % were in stage 4, and 5.5 % were in stage 5. Nonglomerular renal diseases were the primary cause of CKD, comprising 51.9 % of the patients with CKD. The age at disease onset, gender, CKD stage distribution, and proportion of co-morbidities varied between the glomerular and nonglomerular CKD cases. Anemia, hyperlipidemia, hypocalcemia, and hyperphosphatemia were more prevalent in patients with glomerular CKD. The overall prevalence of complications was as follows: uncontrolled blood pressure, 44.1 %; anemia, 34.2 %; hyperlipidemia, 44.9 %; short stature, 10.3 %; and failure to thrive, 8.2 %. Uncontrolled blood pressure (BP), anemia, and hyperlipidemia were common, even in the early CKD stages. The prevalence of CKD complications generally increased with the worsening stage of CKD.

CONCLUSIONS

This study reveals differences in CKD etiology and prevalence of specific complications according to the stage of CKD. Early recognition and awareness of complications are mandatory for clinicians during the follow-up visits of children with CKD.

'Targeted top down' approach for the investigation of UTI: A 10-year follow-up study in a cohort of 1000 children

INTRODUCTION

Investigations following urinary tract infection (UTI) aim to identify children who are prone to renal scarring, which may be preventable. In 2002, in an attempt to reduce unnecessary intervention, the present institution standardised the investigation of children with a confirmed UTI.

OBJECTIVE

This study aimed to identify the significance of urological abnormalities on investigations following a UTI in children, prior to the introduction of the National Institute for Health and Care Excellence (NICE) guidelines.

METHODS

Clinical information on the first 1000 patients was retrieved from a prospective UTI hospital database. The follow-up period was 10 years.

RESULTS

There were 180 males and 820 females (M:F = 1:4.5). The median age of presentation was 5 years (range 11 days-16 years). A renal ultrasound (US) was performed on all patients, and was normal in 93% of cases (n = 889) (see Figure). Of the 7% who had an abnormal US (n = 71), 54 were female and 17 male (M:F = 1:3). A total of 372 DMSA scans were requested and 350 attended their appointment. Of these, 278 cases (79%) were reported as normal, while 72 had an abnormality documented. Of these 72 patients with abnormalities on DMSA scan, 49 had a repeat DMSA scan: 30 demonstrated permanent scarring, while the DMSA scan became normal in 19. Sixteen of the 278 patients whose DMSA scan was initially normal had a repeat DMSA scan due to symptoms, and all scans were normal. Twelve (1.2%) patients required surgical intervention: three underwent circumcision for recurrent UTIs; three underwent endoscopic treatment of VUR; one had a PUV resection; one underwent a cystoscopy; three had a pyeloplasty for pelvi-ureteric junction obstruction; and one had a ureteric reimplantation for vesico-ureteric junction obstruction. After initial investigations and management, 936 patients were discharged from the UTI clinic: 47 of them re-presented - 40 with recurrent UTIs and seven with dysuria. Thirty-five of the 47 children who re-presented with urological symptoms underwent a DMSA scan, which showed scarring in three (6%).

DISCUSSION

Only 12% of children have a significant radiological abnormality picked up on investigation following a UTI. The present investigation approach differed from the NICE guidelines, where imaging is based on patient age and characteristics of the UTI. All children had a renal US, while DMSA scans were reserved for those children <1 year of age or those with upper tract symptoms. The present protocol recommended a renal US in all children presenting with a UTI. This promptly identified those with pelvi-ureteric junction obstruction and those with PUV, who all presented >6 months of age with a single UTI and, therefore, based on the NICE guidelines would not have undergone a renal US. Of the children who re-presented with further UTIs, a significant number were found to have dysfunctional voiding. As this link is well reported, it may be appropriate to screen for this in older children at initial presentation. Only three patients, who had a US at presentation, were subsequently found to have scarring on DMSA. After 10 years of follow-up, this could represent a false negative rate of 0.3% for the screening programme. None of the girls were found to have VUR or needed any surgical intervention, which suggested that early identification of the scarring might not have altered management. Few patients required surgical intervention, all of whom were identified early. No patient who re-presented required intervention. This would suggest that the present protocol is effective at picking up abnormalities that require surgical management.

CONCLUSION

This study suggested that after a childhood UTI, the liberal use of renal ultrasound and a focused 'top down' approach to investigation is likely to identify the vast majority of children who require intervention.

Risk Factors for Recurrent Urinary Tract Infection and Renal Scarring

OBJECTIVES

To identify risk factors for recurrent urinary tract infection (UTI) and renal scarring in children who have had 1 or 2 febrile or symptomatic UTIs and received no antimicrobial prophylaxis.

METHODS

This 2-year, multisite prospective cohort study included 305 children aged 2 to 71 months with vesicoureteral reflux (VUR) receiving placebo in the RIVUR (Randomized Intervention for Vesicoureteral Reflux) study and 195 children with no VUR observed in the CUTIE (Careful Urinary Tract Infection Evaluation) study. Primary exposure was presence of VUR; secondary exposures included bladder and bowel dysfunction (BBD), age, and race. Outcomes were recurrent febrile or symptomatic urinary tract infection (F/SUTI) and renal scarring.

RESULTS

Children with VUR had higher 2-year rates of recurrent F/SUTI (Kaplan-Meier estimate 25.4% compared with 17.3% for VUR and no VUR, respectively). Other factors associated with recurrent F/SUTI included presence of BBD at baseline (adjusted hazard ratio: 2.07 [95% confidence interval (CI): 1.09-3.93]) and presence of renal scarring on the baseline (99m)Tc-labeled dimercaptosuccinic acid scan (adjusted hazard ratio: 2.88 [95% CI: 1.22-6.80]). Children with BBD and any degree of VUR had the highest risk of recurrent F/SUTI (56%). At the end of the 2-year follow-up period, 8 (5.6%) children in the no VUR group and 24 (10.2%) in the VUR group had renal scars, but the difference was not statistically significant (adjusted odds ratio: 2.05 [95% CI: 0.86-4.87]).

CONCLUSIONS

VUR and BBD are risk factors for recurrent UTI, especially when they appear in combination. Strategies for preventing recurrent UTI include antimicrobial prophylaxis and treatment of BBD.

Impact of common functional polymorphisms in renin angiotensin system genes on the risk of renal parenchymal scarring following childhood urinary tract infection

BACKGROUND

Pathogenesis of renal parenchymal scarring (RPS) after acute pyelonephritis (APN) is unclear. The risk of RPS varies markedly among individuals, suggesting a genetic role.

OBJECTIVE

To investigate a possible role of common polymorphisms in renin angiotensin system genes in APN-associated RPS in children.

PATIENTS AND METHODS

This study included 104 APN children and 300 controls. APN was diagnosed by urine culture and typical findings on 99Tc-DMSA scans. Voiding cystourethrogram tested the presence of vesicoureteral reflux (VUR). Follow-up DMSA scans were performed 4-6 months later to identify new RPS. Angiotensin converting enzyme gene I/D, angiotensin II receptor type-1 A1166C and angiotensinogen M235T polymorphisms were genotyped.

RESULTS

New RPS developed in 44.2% (46/104) of children with APN. VUR was diagnosed in 35.6% (37/104) of APN cases. RPS developed in 73% of cases of VUR. The D allele of ACE gene I/D polymorphism was significantly more common in APN cases with RPS (73.91%) than non-RPS (58.6%) and controls (54.5%) (p = 0.021, p = 0.002, respectively). The AGTR-1 A1166C A allele was significantly more common in VUR than the non-reflux children (91.9% versus 76.1%; p = 0.005). VUR, in contrast to the D allele (OR 6.1, 95% CI 0.878-19.7; p = 0.05), was an independent risk factor for RPS.

DISCUSSION

ACE gene D allele is associated with a twofold increase in RPS risk, which could be a result of a functional effect to increase tissue levels and activity of ACE during APN. However, D allele failed to qualify as an independent risk and its RPS association could be dependent on other co-factors, such as TGFβ1 activation, or the D-allele might link with recently discovered functional polymorphisms at the 5' end of the ACE gene. Although VUR is an independent risk for RPS, it is not clear whether this is due to exposure of the kidneys to infected urine, or VUR-associated dysplasia. In contrast with published literature, we noted higher rates of RPS and high-grade VUR, suggesting a more aggressive VUR course or local unawareness of APN. Our study has its limitations; the small number of VUR children, and the clinical and ethical difficulties of testing VCUG and DMSA in controls.

CONCLUSIONS

ACE gene D allele is associated with, but cannot independently predict, RPS in children. VUR is an independent risk for post-pyelonephritic scarring. AGTR-1 1166A/C polymorphism is associated with occurrence, but not progression, of VUR.

Long-term, low-dose prophylaxis against urinary tract infections in young children

Urinary tract infection (UTI) affects about 2 % of boys and 8 % of girls during the first 6 years of life with Escherichia coli as the predominant pathogen. Symptomatic UTI causes discomfort and distress, and carries a risk of inducing renal damage. The strong correlation between febrile UTI, dilating vesicoureteral reflux (VUR), and renal scarring led to the introduction of antibiotic prophylaxis for children with VUR to reduce the rate of UTI recurrence. It became common practice to use prophylaxis for children with VUR and other urinary tract abnormalities. This policy has been challenged because of a lack of scientific support. Now, randomized controlled studies are available that compare prophylaxis to no treatment or placebo. They show that children with normal urinary tracts or non-dilating VUR do not benefit from prophylaxis. Dilating VUR may still be an indication for prophylaxis in young children. After the first year of life, boys have very few recurrences and do not benefit from prophylaxis. Girls with dilating VUR, on the other hand, are more prone to recurrences and benefit from prophylaxis. There has been a decline in the use of prophylaxis due to questioning of its efficacy, increasing bacterial resistance, and a propensity to low adherence to medication. Alternative measures to reduce UTI recurrences should be emphasized. However, in selected patients carefully followed, prophylaxis can protect from recurrent UTI and long-term sequelae. 1. There is a strong correlation between UTI, VUR, and renal scarring. 2. Children with normal urinary tracts or non-dilating VUR do not benefit from prophylaxis. 3. Young children, mainly girls, with dilating VUR are at risk of recurrent UTI and acquired renal scarring and seem to gain from antibiotic prophylaxis. 4. Increasing bacterial resistance and low adherence with prescribed medication is a major obstacle to successful antibiotic prophylaxis.

Vesicoureteric reflux in children

Vesicoureteric reflux is defined as the retrograde passage of urine from the bladder into one or both ureters and often up to the kidneys, and mainly affects babies and infants. In severe cases dilatation of the ureter, renal pelvis, and calyces might be seen. Traditionally it was thought that only a low percentage of children have vesicoureteric reflux, but studies have suggested as many as 25-40% are affected. Guidelines recommend that the number of investigations for vesicoureteric reflux in children who have had a febrile urinary tract infection be reduced, but this approach is controversial. The recommendations also suggest that prophylactic antibiotics and surgery should be avoided in children with non-severe vesicoureteric reflux. In this Seminar I present data on the management of children with vesicoureteric reflux and give suggestions on how to navigate this difficult area.

Effective endoscopic diagnosis and treatment of pediatric occult vesicoureteral reflux with intermediate to long-term follow-up

PURPOSE

Recurrent febrile urinary tract infections (fUTIs) in children with non-diagnostic voiding cystourethrogram (VCUG) are challenging, as misdiagnosis can lead to renal damage and increased morbidity. We compared fUTI rates before and after endoscopic treatment of patients with suspected occult VUR.

METHODS

Between January 2009 and December 2012, children with history of fUTI and non-diagnostic VCUG(s) underwent endoscopic ureteral hydrodistention (HD) and injection of dextranomer hyaluronic acid co-polymer (Dx/HA). fUTI rates before and after intervention were evaluated. Demographics, imaging and endoscopic findings were assessed.

RESULTS

Thirty-four children (mean age 5.4±2.8 years) underwent bilateral Dx/HA injection for occult VUR. Average follow-up was 28.8 months. Seventeen children had renal scarring. Mean ureteral HD grade was 2.2/3. HD grade for ureters associated with renal scarring was significantly (p<0.05) higher (2.6/3) than those without scarring (2.0/3). Mean injected volume was 1.2 mL. Ureters associated with renal scarring (n=21) required significantly (p<0.05) higher volumes (1.4 mL) than those without scarring (n=47; 1.1 mL). Prior to intervention, the fUTI rate was 0.15/patient/month compared to just 0.02 after treatment (p<0.0001).

CONCLUSIONS

Incidence of fUTIs significantly decreased following treatment, supporting the use of Dx/HA injection in carefully selected children when the suspicion for occult VUR is high.

The diagnosis, evaluation and treatment of acute and recurrent pediatric urinary tract infections

Urinary tract infection (UTI) is one of the most common bacterial infections encountered by pediatricians. Currently, the diagnosis and management of acute UTI and recurrent UTI in children remain controversial. Recently published guidelines and large clinical trials have attempted to clarify UTI diagnostic and management strategies. In this manuscript, we review the diagnosis and management of acute and recurrent UTI in the pediatric population.

Controversy in urinary tract infection management in children: a review of new data and subsequent changes in guidelines

Controversy and lack of consensus have been encountered in the management of pediatric urinary tract infection (UTI), including its diagnosis, radiological investigations and the use of antibiotic therapy. In this review, we discuss the need for radiological investigations and the extent of their use as well as the need for prophylactic antibiotics in children with UTI and vesicoureteral reflux. Only a small proportion of children with first UTI and no history of antenatal renal abnormalities have clinically important malformations. Renal ultrasound should be performed in febrile infants and young children with UTI; a micturating cystourethrogram should not be performed routinely after the first febrile UTI. Long-term antibiotics appear to reduce the risk of recurrent symptomatic UTI in susceptible children, although the clinical benefit is marginal. Current recommendations encourage performing radiological investigations only in children at risk and discourage routine prophylactic antibiotic use.