Update on recent guidelines for the management of urinary tract infections in children: the shifting paradigm

Conflicting views of physicians and surgeons concerning pediatric urinary tract infection: a comparative review

BACKGROUND

A first febrile urinary tract infection (UTI) is a common condition in children, and pathways of management have evolved over time.

OBJECTIVE

To determine the extent to which pediatricians and surgeons differ in their investigation and management of a first febrile UTI, and to evaluate the justifications for any divergence of approach.

MATERIALS AND METHODS

A literature search was conducted for papers addressing investigation and/or management following a first febrile UTI in children published between 2011 and 2021. Searches were conducted on Medline, Embase, and the Cochrane Controlled Trials Register. To be eligible for inclusion, a paper was required to provide recommendations on one or more of the following: ultrasound (US) and voiding cystourethrogram (VCUG), the need for continuous antibiotic prophylaxis and surgery when vesicoureteral reflux (VUR) was detected. The authorship required at least one pediatrician or surgeon. Authorship was categorized as medical, surgical, or combined.

RESULTS

Pediatricians advocated less imaging and intervention and were more inclined to adopt a "watchful-waiting" approach, confident that any significant abnormality, grades IV-V VUR in particular, should be detected following a second febrile UTI. In contrast, surgeons were more likely to recommend imaging to detect VUR (p<0.00001), and antibiotic prophylaxis (p<0.001) and/or surgical correction (p=0.004) if it was detected, concerned that any delay in diagnosis and treatment could place the child at risk of kidney damage. Papers with combined authorship displayed intermediate results.

CONCLUSION

There are two distinct directions in the literature regarding the investigation of an uncomplicated first febrile UTI in a child. In general, when presented with a first febrile UTI in a child, physicians recommend fewer investigations and less treatment, in contrast to surgeons who advocate extensive investigation and aggressive intervention in the event that imaging detects an abnormality. This has the potential to confuse the carers of affected children.

Renal scars in children with febrile urinary tract infection - Looking for associated factors

INTRODUCTION

Febrile urinary tract infection (UTI) is a common childhood infection related to renal scarring and potentially long-term complications like chronic kidney disease. It would be of great benefit to find a correlation between easy-accessible factors in the acute phase of a febrile UTI and the development of renal scar formation and/or decreased renal function in order to identify children at risk of future complications.

OBJECTIVE

The aim of this study was to identify factors associated with the development of decreased split renal function (DSRF) and/or permanent renal scar formation in children with febrile UTI.

STUDY DESIGN

The medical records of 212 Children aged 0 months to 15 years with febrile UTI admitted to The Pediatric Department of Lillebaelt Hospital, Kolding from January 2011 to September 2014 were systematically reviewed. We analyzed clinical, laboratory, and radiologic findings. Statistical analysis was performed to identify factors associated with renal scar formation and DSRF on nuclear imaging at 6 months follow-up.

RESULTS

A total of 113 medical records were eligible for further analysis, 99 girls and 14 boys, 34 patients younger than 12 months. In total 30 patients (26.5%) had an abnormal follow-up imaging (DSRF less than 45% and/or renal scarring). Nine patients (8%) had renal scarring. Four patients (3.5%) had renal scarring only, 21 patients (18.6%) had DSRF only, and five patients (4.4%) had both renal scarring and DSRF. Patients with renal scar formation on follow-up imaging had significantly higher C-reactive protein (CRP) than patients with no scarring (p < 0.01). CRP and absolute neutrophil count (ANC) was significantly higher in patients with abnormal follow-up imaging (p < 0.01 and p = 0.010), and these patients more often had positive nitrite in urine dipstick compared to patients with normal kidneys on follow-up (p = 0.048). Temperature above 38.5 °C and CRP >50 mg/L in combination were also associated with a higher risk of abnormal follow-up imaging (p = 0.016).

DISCUSSION

This study contributes with further knowledge to the ongoing debate regarding renal scarring but also reveals the possibility of associated factors for the development of DSRF following a febrile UTI in children. However, due to the retrospective design as well as the small number of events in our study definite conclusions on whether the above-mentioned factors are indeed prognostic for the development of renal scarring or DSRF following a febrile UTI can not be drawn.

Management of Pediatric Urinary Tract Infections: A Delphi Study

Urinary tract infection (UTI) is one of the most common infectious diseases in the pediatric population and represents a major cause of antibiotic consumption and hospitalization in children. Considering the ongoing controversies on the management of pediatric UTI and the challenges due to increasing antimicrobial resistance, the aim of the present study was to evaluate the level of agreement on UTI management in pediatric age in Emilia-Romagna Region, Italy, and to assess on the basis of recent studies whether there is the need to change current recommendations used by primary care pediatricians, hospital pediatricians, and pediatric surgeons in everyday clinical practice to possibly improve outcomes. This consensus provides clear and shared indications on UTI management in pediatric age, based on the most updated literature. This work represents, in our opinion, the most complete and up-to-date collection of statements on procedures to follow for pediatric UTI, in order to guide physicians in the management of the patient, standardize approaches, and avoid abuse and misuse of antibiotics. Undoubtedly, more randomized and controlled trials are needed in the pediatric population to better define the best therapeutic management in cases with antimicrobial resistance and real usefulness of long-term antibiotic prophylaxis.

SNMMI procedure standard/EANM practice guideline on pediatric [99mTc]Tc-DMSA renal cortical scintigraphy: an update

The Society of Nuclear Medicine and Molecular Imaging (SNMMI), founded in 1954, is an international scientific and professional organization with a purpose to promote the science, technology, and practical application of nuclear medicine. The European Association of Nuclear Medicine (EANM), founded in 1985, is a nonprofit professional medical association with a purpose to facilitate international communication among individuals in nuclear medicine pursuing clinical and academic excellence. Members of the SNMMI and EANM are physicians, technologists, and scientists who specialize in the research and practice of nuclear medicine. The SNMMI and EANM will periodically publish new guidelines for nuclear medicine practice to further advance the science of nuclear medicine and improve patient care. Existing standards/guidelines will be reviewed for revision or renewal, as appropriate. Each standard/guideline, representing a policy statement by the SNMMI/EANM, has undergone a thorough review, and represents an expert consensus. The SNMMI and EANM recognize that the safe and effective use of diagnostic nuclear medicine imaging requires specific training and skills, as described in each document. These standards/guidelines are educational resources designed to assist practitioners in providing appropriate nuclear medicine care for patients. They are consensus documents, and are not mandatory provisions or requirements of practice. They are not intended, nor should they be used, to establish a legal standard of care. For these reasons and those set forth below, the SNMMI and the EANM cautions against the use of these standards/guidelines in litigation procedures that call into question the clinical decisions of a practitioner. The ultimate judgment regarding the appropriateness and propriety of any specific procedure or course of action must be made by medical professionals, taking into account the unique context of each case. Thus, there is no implication that action differing from what is detailed in these standards/guidelines, on its own, is below the standard of care. On the contrary, a conscientious practitioner may responsibly adopt a course of action different from that set forth in the standards/guidelines when, based on the reasonable judgment of the practitioner, such course of action is warranted based on the condition of the patient, limitations of available resources, or advances in knowledge or technology subsequent to publication of the standards/guidelines. Practicing medicine involves not only the science, but also the art of dealing with the prevention, detection, diagnosis, and treatment of disease. The variety and complexity of human conditions make it impossible for general guidelines to consistently allow for an accurate diagnosis to be reached or a specific treatment response to be predicted. Therefore, it should be recognized that adhering to these standards/guidelines does not ensure a successful outcome. All that should be expected is that a practitioner follows a reasonable course of action based on their level of training, the current landscape of knowledge, the resources at their disposal, and the needs/context of the particular patient being treated. The purpose of this document is to provide nuclear medicine physicians, radiologists, and other clinicians with guidelines for the recommendation, performance and interpretation of 99mTc-dimercaptosuccinic acid renal cortical scintigraphy ([99mTc] Tc-DMSA scintigraphy) in pediatric patients. These recommendations represent the expert opinions of experienced leaders in this field, and these recommendations are not all supported by a high level of evidence. Further studies are required to have evidence-based recommendations for the application of [99mTc] Tc-DMSA renal cortical scintigraphy in pediatrics. This guideline summarizes the views of the SNMMI Renal Cortical Scintigraphy in Children Working Group and the EANM Pediatrics Committee. It reflects recommendations for which the SNMMI and EANM cannot be held responsible. The recommendations should be taken into context of good practice of nuclear medicine and do not substitute for national and international legal or regulatory provisions.

Pediatric Nephro-Urology: Overview and Updates in Diuretic Renal Scans and Renal Cortical Scintigraphy

Nuclear medicine offers several diagnostic scans for the evaluation of congenital and acquired conditions of the kidneys and urinary track in children. Tc-99m-MAG 3 diuretic renal scans are most commonly used in the evaluation and follow up of urinary track dilatations. They provide functional information on the differential renal function and on drainage quality which is allows distinction between obstructed and non-obstructed kidneys and the need for surgical correction vs conservative management in kidneys with impaired drainage. Standardized imaging and processing protocols are essential for correct interpretation and for meaningful comparisons between follow up scans. Different approaches and conceptions led to some contradicting recommendations between SNMMI and EANM guidelines on diuretic renography in children which caused confusion and to the emergence of self-made institutional protocols. In Late 2018 the two societies published joint procedural guidelines on diuretic renography in infants and children which hopefully will end the confusion. Tc-99m DMSA scans provide important information about the function of the renal cortex allowing detection of acute pyelonephritis, renal scars dysplasia and ectopy as well as accurate determination of the differential renal function. They are commonly used in the evaluation of children with urinary tract infections and affect clinical management. A standardized imaging and processing protocol improves the diagnostic accuracy of these studies. SPECT or pinhole images should be a routine part of the imaging protocol. This is one of the recommendations in the new EANM and SNMMI procedural guidelines for renal cortical scintigraphy in children available online on the SNMMI website and is under publication. This article provides an overview on the clinical role of diuretic renography and cortical scintigraphy in children and describes the imaging protocols focusing on the new recommendations in the procedural guidelines.

Virus-related neurological lower urinary tract dysfunction: Lessons learned during 4-year follow-up of patients with Congenital Zika Syndrome

INTRODUCTION

We have previously reported on neurogenic bladder dysfunction among Congenital Zika Vírus Syndrome (CZS) patients, but it is unknown how they will respond to treatment.

OBJECTIVE

To assess whether children with neurological lower urinary tract dysfunction and CZS will respond to Standard therapies.

METHODOLOGY

A prospective observational cohort study of children with CZS referred for urological assessment between 2016 and 2020 to our quaternary center in Brazil. Urological protocol included clinical history, urinalysis and culture, renal and bladder ultrasonography and urodynamic study. Patients were treated based on findings from the first evaluation, with oxybutynin chloride for overactive bladder and low bladder compliance, clean intermittent catheterization for ineffective bladder emptying, or dual therapy when both were observed. Urological outcomes were evaluated between the first and second visits considering patient's adherence. Outcomes measured included clinical, imaging, and urodynamic variables. Data was analyzed using the IBM SPSS 22 software.

RESULTS

From the cohort of 90 patients, 56 completed the second urodynamic assessment and were included. One presented underactive bladder and 55 overactive bladder. Among these 55, 39 were adherent and 16 non-adherents to the prescribed treatment. Among the 39 adherents, 8 adhered regularly to oxybutynin and clean intermittent catheterization (CIC), 29 to oxybutynin alone, and two to catheterization alone. During follow-up, the number of patients with urinary tract infection and postvoid residual increased, but all other parameters had improved. Renal and bladder ultrasonography improved in 10, maximum bladder pressure decreased in 22 and maximum cystometric capacity and compliance increased in 14 patients. Sixteen patients did not adhere regularly to the prescribed treatment and although the number of patients with urinary tract infection reduced with antibiotic therapy, their bladder capacity and compliance did not improve during follow-up.

DISCUSSION

Ultrasonographic and urodynamic improvements were observed after 10.8 ± 7.5 months of treatment, including one patient with ureterohydronephrosis that resolved. Adherence to CIC remains a challenge and reflected in the number of patients presenting urinary tract infection and postvoid residual. The immediate clinical relevance is the major study strength, given the previously uncharacterized therapy options for this patient population. The number of patients remains one of the study limitations, reducing our ability to perform more advanced statistical analyses.

CONCLUSION

Patients with Zika-related neurological lower urinary tract dysfunction may benefit from conventional therapies. Results confirmed ultrasonographic and urodynamic improvements after treatment, although not statically significant. Adherence to treatment, specifically to CIC, remains a challenge.

Serum Interleukin-6 and Interleukin-8 are Sensitive Markers for Early Detection of Pyelonephritis and Its Prevention to Progression to Chronic Kidney Disease

Background:

Pyelonephritis is the most common bacterial infection in children that can cause renal failure if not diagnosed or treated early. We used serum biomarker interleukins (IL-6 and IL-8) and then confirmed the results by the findings dimercaptosuccinic acid (DMSA) scan to distinguish upper-tract infection from lower-tract infection.

Methods:

Serum IL-6 and IL-8 were measured in 57 children with newly diagnosed untreated urinary tract infection (UTI) documented by a positive urine culture. All children had a DMSA to determine whether serum IL6, IL-8 can be used as a marker to predict upper-tract from lower-tract infection. IL-6 and IL8 were determined by the enzyme link immunosorbent assay (ELISA) technique.

Results:

Of the 57 patients, 24 (42%) had renal parenchymal lesions on the DMSA scan. Patients with abnormal DMSA had significantly higher serum IL-6 and IL-8 compared with those with normal DMSA scan (187.1 ± 113.1 ng/mL vs. 396.1 ± 246.0 ng/mL, P = 0.005; and 165 ± 76.1 ng/mLvs. 190.8 ± 60.8 ng/mL, P = 0.026, respectively). Pyelonephritis was more frequent in children younger than 20 months old (n = 36, 63%, P < 0.005) and more prevalent in girls (n = 36, 63%, P = 0.005). Serum IL-6 had a sensitivity of 67.3% and a specificity of 63.0% and serum IL8 had a sensitivity of 80.1% and a specificity of 73.5% in the differential diagnosis of pyelonephritis and cystitis (P = 0.03).

Conclusions:

Serum levels of IL-6 and IL-8 are both sensitive biomarkers of UTI and can discriminate the upper from lower tract urinary infections. Determination of these biomarkers may help to identify patients with acute pyelonephritis and need for DMSA study.

"Effect of Subinhibitory Concentrations of Some Antibiotics and Low Doses of Gamma Radiation on the Cytotoxicity and Expression of Colibactin by an Uropathogenic Escherichia coli isolate"

Colibactin and cytotoxic necrotizing factor 1 (Cnf 1) are cyclomodulins secreted by uropathogenic E. coli. In this study, uropathogenic E. coli expressing colibactin and Cnf 1 was exposed to antibiotics subMICs and gamma radiation to investigate their effects on its cytotoxicity and expression of colibactin. The test isolate was exposed to three subMIC levels of levofloxacin, ciprofloxacin, trimethoprim/sulfamethoxazole and ceftriaxone and irradiated with gamma rays at 10 and 24.4 Gy. The cytotoxicity for either antibiotic or gamma rays treated cultures was measured using MTT assay and the expression of colibactin encoding genes was determined by RT-PCR. Treatment with fluoroquinolones nearly abolished the cytotoxicity of E. coli isolate and significantly downregulated clbA gene expression at the tested subMICs (P ≤ 0.05) while trimethoprim/sulfamethoxazole treated cultures exerted significant downregulation of clbA and clbQ genes at 0.5 MIC only (P ≤ 0.05). Ceftriaxone treated cultured exhibited reduction in the cytotoxicity and insignificant effects on expression of clbA, clbQ and clbM genes. On contrast, significant upregulation in the expression of clbA and clbQ genes was observed in irradiated cultures (P ≤ 0.05). Fluoroquinolones reduced both the cytotoxicity of UPEC isolate and colibactin expression at different subMICs while ceftriaxone at subMICs failed to suppress the expression of genotoxin, colibactin, giving an insight to the risks associated upon their choice for UTI treatment. Colibactin expression was enhanced by gamma irradiation at doses resembling these received during pelvic radiotherapy which might contribute to post-radiotherapy complications.

Efficacy of Probiotic Prophylaxis After The First Febrile Urinary Tract Infection in Children With Normal Urinary Tracts

BACKGROUND

Growing antibiotic resistance and debates over their efficacy for urinary tract infection (UTI) recurrence warrants studying nonantibiotic prophylaxis for preventing UTI recurrences.

METHODS

We randomly assigned 181 children, aged 4 months to 5 years, with a normal urinary tract after recovery from their first febrile UTI in a 1:1 ratio to receive a probiotic mixture of Lactobacillus acidophilus, Lactobacillus rhamnosus, Bifidobacterium bifidum, and Bifidobacterium lactis (n = 91) or placebo (n = 90) for a total of 18 months of therapy. The primary objective was to show the superiority of probiotic prophylaxis to placebo. The primary end point was composite cure (UTI-free survival) at 18 months, and the secondary end point was the median time to first UTI recurrence.

RESULTS

The probiotics were superior to placebo with respect to the primary efficacy end point. At 18 months, composite cure was observed in 96.7% (3 of 91) of the patients in the probiotic group and 83.3% (15 of 90) of those in the placebo group (P = .02). The median time to the first incidence of UTI recurrence was 3.5 months (range, 1-4 months) and 6.5 months (range, 2-14 months) in the probiotic and placebo groups, respectively (P = .04). The main microorganism that caused recurrent UTI was Escherichia coli, followed by Klebsiella pneumoniae, and these results were not significantly different between the 2 groups. We found no specific adverse events among the participants who received the probiotic mixture during the course of therapy.

CONCLUSIONS

The probiotics were more effective than placebo at reducing the risk of recurrent UTI in children with a normal urinary tract after their first episode of febrile UTI.

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.

Role of Late DMSA Renal Scan in Detecting High-Grade Vesicoureteral Reflux

OBJECTIVE

To determine the performance of late dimercaptosuccinic acid (DMSA) renal scans in identifying high-grade (III-V) vesicoureteral reflux (VUR) in children aged over 3 y with a febrile urinary tract infection (fUTI) history that has not been timely investigated.

METHODS

In this retrospective study of diagnostic accuracy, the clinical records of children aged between 3 and 18 y with fUTI history evaluated consecutively at Nephrology Unit of Hospital General de Niños Pedro de Elizalde, Argentina between 2006 and 2016 were reviewed. Patients with previously diagnosed renal or urinary tract abnormalities or who underwent previous postnatal genitourinary imaging were excluded. Only those assessed by renal and bladder ultrasound (RBUS), voiding cystourethrogram (VCUG) and late 6-mo DMSA scan were analyzed. The ability of the scintigraphy in identifying high-grade VUR was determined by comparing its findings with those of VCUG.

RESULTS

In 122 children (median age 5.37 y, 88.5% girls) RBUS was abnormal in 53 (43.4%) and 58 (47.5%) had VUR (30 of high-grade). Abnormal DMSA scan findings (70 patients, 57.4%) were associated with all grade (p = 0.00001) and with high-grade VUR (p = 0.00001). Sensitivity, specificity, negative (NPV) and positive (PPV) predictive values of late DMSA scans for all grades VUR were 93.1%, 75%, 92.3% and 77.1%, respectively. Only 4 patients with low-grade VUR had normal scans. For high-grade VUR, sensitivity and NPV reached 100%.

CONCLUSIONS

In older children, the normal late DMSA scan predicted the absence of high-grade VUR, obviating the need for a VCUG. This approach could be a possible strategy for children not studied at acute infection time.

Urinary angiotensinogen in pediatric urinary tract infection

BACKGROUND

Urinary tract infection (UTI) is one of the most common diseases in children, and urinary angiotensinogen (U-AGT) is a new biomarker gathering attention in many renal diseases. U-AGT reflects intrarenal renin-angiotensin system (RAS) activity. We conducted a study to measure U-AGT in children <4 months old with UTI.

METHODS

All children <4 months old who came to Toshima Hospital with fever between January 2015 and December 2015 were included. Patients were divided into a UTI group and a non-UTI group, and U-AGT was measured.

RESULTS

Median U-AGT was higher in patients with UTI compared with patients without UTI: (0.56 ng/dL, range, 0.025-2.753 ng/dL vs 0.13 ng/dL, range, 0.008-1.697 ng/dL, respectively; P < 0.05).

CONCLUSIONS

U-AGT is elevated in UTI patients, and RAS activation may contribute to renal injury caused by UTI.

Is Vitamin D Supplementation Effective in Prevention of Recurrent Urinary Tract Infections in the Pediatrics? A Randomized Triple-Masked Controlled Trial

Background:

This study aimed to evaluate the impact of Vitamin D supplementation on prevention of recurrent urinary tract infections (UTIs) in the pediatrics.

Materials and Methods:

This randomized, triple-blind, placebo-controlled clinical trial was conducted in 2014 among 68 children and adolescents with recurrent UTI. They were randomly assigned to two groups, receiving either Vitamin D (1000 IU/daily) or placebo for 6 months. The serum concentration of Vitamin D before and after the study and the frequency of UTI during the study were recorded.

Results:

Overall 33 patients in the group of receiving Vitamin D and 32 in the placebo group completed the trial. The mean serum level of Vitamin D had a significant increase in the intervention group (15.80 ± 8.7 vs. 20.56 ± 8.30 ng/mL, P < 0.001) and significant decrease in the placebo group (20.43 ± 13.28 vs. 17.43 ± 9.99 ng/mL, P = 0.041). During the trial, the frequency of UTI was not significantly different between the two groups studied (P = 0.72). Both before and after the trial, the frequency of Vitamin D deficiency, insufficiency, and adequacy was not significantly different within and between groups (P > 0.05).

Conclusion:

The findings of this trial revealed that Vitamin D supplementation with the mentioned dose have not significant impact on preventing recurrent UTI. Future studies with higher doses of Vitamin D and longer follow-up are suggested.

Changing outpatient referral patterns in a small pediatric nephrology practice

Background

We have noted a large number of referrals for abnormal kidney imaging and laboratory tests and postulated that such referrals have increased significantly over time. Understanding changes in referral patterns is helpful in tailoring education and communication between specialists and primary providers.

Methods

We performed a retrospective chart review of new patient referrals to Mary Bridge Children’s Nephrology clinic for early (2002 to 2004) and late (2011 to 2013) cohorts. The overall and individual frequencies of referrals for various indications were compared.

Results

The overall number of new visits was similar for early (511) and late (509) cohorts. The frequency of referrals for solitary kidneys and multi-cystic dysplastic kidneys, microalbuminuria and abnormal laboratory results increased significantly (Odds Ratio (OR) and 95% Confidence Interval of OR: 1.920 [1.079, 3.390], 2.862 [1.023, 8.006], 2.006 [1.083, 3.716], respectively) over the time interval while the proportion of referrals for urinary tract infections (UTIs) and vesicoureteral reflux (VUR) decreased by half (OR: 0.472, 95% CI: 0.288, 0.633). Similarly, referrals for urinary tract dilation and hydronephrosis occurred significantly less often (8% versus 6%, OR: 0.737, 95% CI: 0.452, 1.204) with similar changes in referrals for voiding issues (OR: 0.281, 95% CI: 0.137, 0.575). However, these changes were not statistically significant. Frequencies for other indications showed little variation.

Conclusions

Changes in indications for referral likely reflect evolution of practice in management of UTIs and VUR and increased use of imaging and laboratory testing by pediatric providers. These findings have relevance for ongoing education of pediatricians and support the need for collaboration between primary providers and nephrologists to assure the judicious use of resources.

A Putative Role of Apolipoprotein L1 Polymorphism in Renal Parenchymal Scarring Following Febrile Urinary Tract Infection in Nigerian Under-Five Children: Proposal for a Case-Control Association Study

Background

Although urinary tract infection (UTI) resolves with prompt treatment in a majority of children, some children, especially those aged less than 5 years, also develop renal parenchymal scarring (RPS). RPS causes high blood pressure that may lead to severe chronic kidney disease and end-stage renal disease (ESRD). Although the risk of UTI is higher in white children than in black children, it is unknown whether RPS is more common in white children than in black children as data are scarce in this regard. A common genetic predisposition to kidney disease in African Americans and the sub-Saharan African blacks is the possession of apolipoprotein L1 (APOL1). APOL1 risk variants regulate the production of APOL1. APOL1 circulates in the blood, and it is also found in the kidney tissue. While circulating, APOL1 kills the trypanosome parasites; an increased APOL1 in kidney tissues, under the right environmental conditions, can also result in the death of kidney tissue (vascular endothelium, the podocytes, proximal tubules, and arterial cells), which, ultimately, is replaced by fibrous tissue. APOL1 may influence the development of RPS, as evidence affirms that its expression is increased in kidney tissue following UTI caused by bacteria. Thus, UTI may be a putative environmental risk factor responsible for APOL1-induced kidney injury.

Objective

The aim of this proposal was to outline a study that seeks to determine if the possession of two copies of either G1 or G2 APOL1 variant increases the risk of having RPS, 6 months following a febrile UTI among Nigerian under-five children.

Methods

This case-control association study seeks to determine whether the risk of RPS from febrile UTI is conditional on having 2 APOL1 risk alleles (either G1 or G2). Cases will be children with a confirmed RPS following a febrile UTI. Controls will be age-, gender-, and ethnic-matched children with a febrile UTI but without RPS. Children with vesicoureteral reflux and other congenital anomalies of the urinary tract are to be excluded. Association between predictor variables (ethnicity, APOL1 G1 or G2, and others) and RPS will be tested at bivariate logistic regression analyses. Predictors that attained significance at a P value of ˂.05 will be considered for multiple logistic regressions. Likelihood-based tests will be used for hypothesis testing. Estimation will be done for the effect size for each of the APOL1 haplotypes using a generalized linear model.

Results

The study is expected to last for 3 years.

Conclusions

The study is contingent on having a platform for undergoing a research-based PhD program in any willing university in Europe or elsewhere. The findings of this study will be used to improve the care of African children who may develop RPS following febrile UTI.

Registered Report Identifier

RR1-10.2196/9514

Is vaginal reflux associated with urinary tract infection in female children under the age of 36 months?

Purpose

To determine the relationship between vaginal reflux (VR) and urinary tract infection (UTI) in female children aged <36 months.

Methods

A single center retrospective study was performed for 191 girls aged <36 months, with a diagnosis of febrile UTI, who underwent a voiding cystourethrography (VCUG) for assessment of vesicoureteral reflux (VUR) at Sanggye Paik Hospital. Fifty-one girls, who underwent VCUG for assessment of congenital hydronephrosis or renal pelvis dilatation, without a UTI, formed the control group. The correlation between the presence and grade of VR and UTI was evaluated.

Results

The prevalence rate of VR was higher in the UTI (42.9%) than control (13.7%) group (P<0.05), with a higher VR severity grade in the UTI (mean, 0.64) than control (mean, 0.18) group (P<0.05). On subanalysis with age-matching (UTI group: n=126, age, 5.28±2.13 months; control group: n=22, age, 4.79±2.40 months; P=0.33), both VR prevalence (43.65% vs. 18.18%, P<0.05) and grade (0.65 vs. 0.22, P<0.05) remained higher in the UTI than control group. Presence and higher grade of VR were associated with UTI recurrence (P<0.05). VR was correlated to urosepsis (P<0.05). The renal defect rate of patients with VR (VR [+]/VUR [+]) was not different from that of patients without VR (74% vs. 52%, P=0.143) in the VUR group; however, it was higher than that of VR (+)/VUR (-) patients (74% vs. 32%, P=0.001). If a child with VR (+)/VUR (+) is exposed to a UTI, the risk of renal defect increases.

Conclusion

Occurrence of VR is associated with UTI recurrence and urosepsis in pediatric female patients.

The value of delta neutrophil index in young infants with febrile urinary tract infection

Delta neutrophil index (DNI) is the fraction of circulating immature granulocytes, which reflects severe bacterial infections and septic condition but has not been studied in urinary tract infection (UTI). Here, we evaluated the value of DNI in predicting acute pyelonephritis (APN) or vesicoureteral reflux (VUR) using the data of 288 patients. Conventional inflammatory markers (white blood cell [WBC] count, erythrocyte sedimentation rate [ESR], C-reactive protein [CRP]), and DNI were measured. WBC, CRP, ESR and DNI were higher in APN than in lower UTI (p < 0.01). Multiple logistic-regression analyses showed that DNI was a predictive factor for areas of lack of uptake on dimercaptosuccinic acid (DMSA) scans (P < 0.01). The area under the receiver operating characteristic (AUC) was also high for DNI (0.622, 95% CI 0.558-0.687, P < 0.01) as well as for CRP (0.731, 95% CI 0.673-0.789, P < 0.01) for the prediction of DMSA defects. DNI demonstrated the highest area under the ROC curve for diagnosis of VUR (0.620, 95% CI 0.542-0.698, P < 0.01). To the best of our knowledge, this is a first study demonstrating that DNI can be used as a diagnostic marker to distinguish APN from lower UTI and function as a diagnostic marker indicative of VUR compared to other conventional markers.

[Renal scarring in children under 36 months hospitalised for acute pyelonephritis]

INTRODUCTION

Acute pyelonephritis (APN) is one of the most common causes of serious bacterial infection in infants. Renal scarring is the most prevalent long-term complication.

OBJECTIVES

To review the incidence of renal scarring within 6 months after an episode of APN in children under 36 months and its relationship with imaging studies, clinical settings, and bacteriology.

METHOD

A retrospective study of previously healthy patients aged one to 36 months, admitted for a first episode of APN, with a minimum follow-up of 6 months. Demographic and clinical variables were collected along with bacteriology, renal and bladder ultrasound scan, voiding cystourethrography, DMSA-scintigraphy, and re-infection events.

RESULTS

A total of 125 patients were included in the study, of which 60% were male, the large majority (92%) febrile, and due to E. coli (74.6%). There was a history of prenatal ultrasound scan changes in 15.4%. Ultrasound scan found dilation of the urinary tract in 22.1%. Voiding cystourethrography was performed on 70 patients: 54.3% no abnormalities, 12.8% vesicoureteral reflux (VUR) grade i-iii, and 32.9% iv-v grade VUR. Six patients had iv-v grade VUR with a normal ultrasound scan. Adherence to DMSA-scintigraphy at 6 months was only 61% of that indicated. Renal scarring was found in 44.3% of those in which it was performed (60 cases).

CONCLUSIONS

Almost half (44%) DMSA-scintigraphy in children aged one to 36 months hospitalised for APN show renal scarring at 6 months, which was found to be associated with the re-infection events and the iv-v grade VUR. There was no relationship between scarring and the bacteriology or the elevations of inflammatory biochemical markers.

Usefulness of neutrophil-lymphocyte ratio in young children with febrile urinary tract infection

PURPOSE

Acute pyelonephritis (APN) is a serious bacterial infection that can cause renal scarring in children. Early identification of APN is critical to improve treatment outcomes. The neutrophil-lymphocyte ratio (NLR) is a prognostic marker of many diseases, but it has not yet been established in urinary tract infection (UTI). The aim of this study was to determine whether NLR is a useful marker to predict APN or vesicoureteral reflux (VUR).

METHODS

We retrospectively evaluated 298 pediatric patients (age≤36 months) with febrile UTI from January 2010 to December 2014. Conventional infection markers (white blood cell [WBC] count, erythrocyte sedimentation rate [ESR], C-reactive protein [CRP]), and NLR were measured.

RESULTS

WBC, CRP, ESR, and NLR were higher in APN than in lower UTI (P<0.001). Multiple logistic regression analyses showed that NLR was a predictive factor for positive dimercaptosuccinic acid (DMSA) defects (P<0.001). The area under the receiver operating characteristic (ROC) curve was high for NLR (P<0.001) as well as CRP (P<0.001) for prediction of DMSA defects. NLR showed the highest area under the ROC curve for diagnosis of VUR (P<0.001).

CONCLUSION

NLR can be used as a diagnostic marker of APN with DMSA defect, showing better results than those of conventional markers for VUR prediction.

A case-based approach to UTI imaging – making sense of the guidelines

Urinary tract infections (UTIs) are common amongst children and invariably result in imaging tests to look for correctable causes that may predispose the child to infection. The objective of imaging is to identify those children at risk of long-term renal damage. The ideal imaging algorithm is extensively debated in the literature owing to the lack of evidence-based data, evolving theories on the pathophysiology of UTI and vesicoureteric reflux (VUR). The present article provides a case-based approach to the imaging of UTIs and proposes guidelines relevant to the South African setting.

Evaluation of new American Academy of Pediatrics guideline for febrile urinary tract infection

PURPOSE

To evaluate the practical applications of the diagnosis algorithms recommended by the American Academy of Pediatrics urinary tract infection (UTI) guideline.

METHODS

We retrospectively reviewed the medical records of febrile UTI patients aged between 2 and 24 months. The patients were divided into 3 groups: group I (patients with positive urine culture and urinalysis findings), group II (those with positive urine culture but negative urinalysis findings), and group III (those with negative urine culture but positive urinalysis findings). Clinical, laboratory, and imaging results were analyzed and compared between the groups.

RESULTS

A total of 300 children were enrolled. The serum C-reactive protein level was lower in children in group II than in those in groups I and III (P<0.05). Children in group I showed a higher frequency of hydronephrosis than those in groups II and III (P<0.05). However, the frequencies of acute pyelonephritis (APN), vesicoureteral reflux (VUR), renal scar, and UTI recurrence were not different between the groups. In group I, recurrence of UTI and presence of APN were associated with the incidence of VUR (recurrence vs. no recurrence: 40% vs.11.4%; APN vs. no APN: 23.3% vs. 9.2%; P<0.05). The incidence of VUR and APN was not related to the presence of hydronephrosis.

CONCLUSION

UTI in febrile children cannot be ruled out solely on the basis of positive urinalysis or urine culture findings. Recurrence of UTI and presence of APN may be reasonable indicators of the presence of VUR.

Recurrent urinary tract infections in children: Preventive interventions other than prophylactic antibiotics

Urinary tract infection (UTI) is one of the most common childhood infections. Permanent renal cortical scarring may occur in affected children, especially with recurrent UTIs, leading to long-term complications such as hypertension and chronic renal failure. To prevent such damage, several interventions to prevent UTI recurrences have been tried. The most established and accepted prevention at present is low dose long-term antibiotic prophylaxis. However it has a risk of break through infections, adverse drug reactions and also the risk of developing antibiotic resistance. The search is therefore on-going to find a safer, effective and acceptable alternative. A recent meta-analysis did not support routine circumcision for normal boys with no risk factors. Vaccinium Macrocarpon (cranberry), commonly used against UTI in adult women, is also effective in reducing the number of recurrences and related antimicrobial use in children. Sodium pentosanpolysulfate, which prevents bacterial adherence to the uroepithelial cells in animal models, has shown conflicting results in human trials. When combined with antibiotic, Lactobacillus acidophilus (LA-5) and Bifidobacterium, by blocking the in vitro attachment of uropathogenic bacteria to uroepithelial cells, significantly reduce in the incidence of febrile UTIs. Deliberate colonization of the human urinary tract of patients with recurrent UTI with Escherichia-coli (E. coli) 83972 has resulted in subjective benefit and less UTI requiring treatment. The non-pathogenic E. coli isolate NU14 DeltawaaL is a candidate to develop live-attenuated vaccine for the treatment and prevention of acute and recurrent UTI. Diagnosing and treating dysfunctional elimination syndromes decrease the incidence of recurrent UTI. A meta-analysis found the lack of robust prospective randomized controlled trials limited the strength of the established guidelines for surgical management of vesicoureteral reflux. In conclusion, several interventions, other than antibiotic prophylaxis, for the prevention of recurrent UTI have been tried and, although showing some promise, they do not provide so far a definitive effective answer. Finding suitable alternatives still requires further high quality research of those seemingly promising interventions.

Evaluation and management of urinary tract infections in the school-aged child

The evaluation and management of urinary tract infection in the school-aged child is an important part of primary care in the ambulatory setting. In this article, the salient features of how this condition presents to the clinician, how it is properly diagnosed and treated, and follow-up care are reviewed.

Diagnostic accuracy of urine heparin binding protein for pediatric acute pyelonephritis

Timely antibiotic initiation for acute pyelonephritis (APN) can prevent renal complications. We investigated whether urine heparin binding protein (UHBP), a cytokine released from activated neutrophils, was a useful diagnostic tool for APN. Febrile children with presumed APN were prospectively enrolled between January and September 2013, and divided into two groups based on urine cultures. UHBP levels were measured at enrollment in all children and 1 month after antibiotic treatment in children with APN. UHBP levels in children with APN at baseline and 1 month versus controls were 47.0 ± 8.4 and 16.6 ± 3.8 vs. 15.0 ± 2.9 ng/mL, respectively (p < 0.001). Test performance characteristics were calculated against a gold standard of positive urine cultures and compared with leukocyte esterase (LE) and nitrite measured by dipsticks and pyuria by microscopy. The sensitivity and specificity for UHBP levels ≥34 ng/mL were 100 and 100 %. Spearman's rank coefficient was used to assess the associations between routine laboratory tests and UHBP levels. Significant positive correlations were found with pyuria grade (Spearman's rho = 0.62; p < 0.001), neutrophil count (rho = 0.38; p = 0.03), and platelet count (rho = 0.39; p = 0.03).

CONCLUSIONS

UHBP is a valid adjunctive diagnostic tool for aiding clinicians in making rapid treatment decisions for APN.

Predictive value of urinary and serum biomarkers in young children with febrile urinary tract infections

BACKGROUND

Early predictive biomarkers for the diagnosis and management of febrile urinary tract infections (UTIs) can be valuable diagnostic tools in children.

METHODS

The study cohort comprised 73 pediatric patients with febrile UTIs [46 with acute pyelonephritis (APN) and 27 with lower UTIs] and 56 healthy children. Urine neutrophil gelatinase-associated lipocalin (uNGAL) and kidney injury molecule-1 (uKIM-1) levels and serum cystatin C (sCysC) levels were measured.

RESULTS

The uNGAL/creatinine (Cr) and uKIM-1/Cr levels were higher in the UTI group than in the controls (P < 0.05). uNGAL/Cr and sCysC levels were higher in patients with APN than in those with lower UTIs (P < 0.05). uNGAL/Cr levels in both the APN and UTI groups decreased following the administration of antibiotics compared to those before treatment (P < 0.05). The uNGAL/Cr level was correlated with serum levels of white blood cells, C-reactive protein, CysC and with uKIM-1/Cr (P < 0.05). uKIM-1/Cr was also correlated with sCysC (P < 0.05). Receiver operating curve analyses showed good diagnostic profiles of uNGAL/Cr and uKIM-1/Cr for identifying UTIs [area under the curve (AUC) 0.9 and 0.66, respectively) and of uNGAL/Cr and sCysC for predicting APN (AUC 0.78 and 0.72, respectively).

CONCLUSIONS

Our results suggest that uNGAL, uKIM-1 and sCysC levels may be useful for predicting and managing febrile UTIs in children.

Predictive risk factors in childhood urinary tract infection, vesicoureteral reflux, and renal scarring management

Approaches to the management of children with urinary tract infection (UTI), vesicoureteral reflux (VUR), and renal scars have been challenged and have become controversial over the past decade. It is difficult to determine when, how, and which patients will benefit from the diagnosis and management of this condition. Therefore, the issues of diagnostic imaging, observation, follow-up, and intervention tend to be decided more on a case-by-case basis, rather than by using an algorithm. Over the past few years, there have been advances in the identification of risk factors that predispose patients with UTI to present with VUR, to develop recurrent UTIs and renal scars, to have deteriorating renal function, to show VUR improvement and/or spontaneous resolution, and to be candidates for and benefit from early surgical intervention.

Five-year assessment of causative agents and antibiotic resistances in urinary tract infections

AIM

To show the distribution and changes of causative agents of urinary tract infections in children and resistance rates by years and select the most appropriate antibiotics.

MATERIAL AND METHODS

In this study, the Başkent University Alanya Research and Application Hospital automation system microbiology recording book was screened retrospectively. Growth of a single microorganism above 105 colonies (cfu/mL) was included in the assessment. Throughout the study, 10 691 urinary cultures were studies and growth was found in 392 (3.7%).

RESULTS

Three hundred and nine (78.8%) of the samples with growth belonged to girls. Growth was found in the neonatal period in 32 patients (8.2%). The most commonly isolated microorganism was Escherichia coli (E. coli) which was found in 68.4% of the patients. Klebsiella spp. were found with a rate of 12.0%; Enterobacter spp. were found with a rate of 10.7% and proteus spp. were found with a rate of 5.1%. Resistance to cefalotin (62.1%), trimethoprim-sulfamethoxasole (43.1%), amoxycillin-clavulanate (34.8%), ampicillin (30.4%), cefixim (26.3%) and nitrofurantoin (3.6%) was found in E. coli species. The antibiotic which had the highest resistance rate was ampicillin with a rate of 93.2% for klebsiella and 83.4% for enterobacter. Klebsiella spp. were the most commonly grown pathogens in newborns (40.6%). In a follow-up period of 5 years, the resistance of E. coli to amoxycillin-clavulanate regressed from 40.3% to 31.3%, while the resistance to trimethoprim-sulfamethoxasole (TMP-SMX) regressed from 45.6% to 34.7%.

CONCLUSIONS

A high resistance against first-generation cephalosporins, ampicillin, amoxycillin-clavulanate and TMP-SMX which are the first-line antibiotics in childhood urinary tract infections was found. Carbapenem (meropenem, imipenem) resistance was not found in our center. Nitrofurantoin, aminoglycosides and cefixime can be recommended for empirical treatment in our hospital because of low resistance. Antibiotic treatment should be redecided according to in vitro antibiotic sensitivity results.