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

Urinary Tract Infections

Urinary tract infection (UTI) is the second most common bacterial infection in children and is considered a public health threat given the mounting rates of antibiotic-resistance among uropathogens. This article highlights recent encouraging developments in UTI research. Further work is necessary to translate the discoveries into accessible, cost-effective technologies that will aid clinicians in real-time decision-making.

Urinary Tract Infection in Children

BACKGROUND

Urinary Tract Infection (UTI) is a common infection in children. Prompt diagnosis and appropriate treatment are very important to reduce the morbidity associated with this condition.

OBJECTIVE

To provide an update on the evaluation, diagnosis, and treatment of urinary tract infection in children.

METHODS

A PubMed search was completed in clinical queries using the key terms "urinary tract infection", "pyelonephritis" OR "cystitis". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature and the pediatric age group. Patents were searched using the key terms "urinary tract infection" "pyelonephritis" OR "cystitis" from www.google.com/patents, http://espacenet.com, and www.freepatentsonline.com.

RESULTS

Escherichia coli accounts for 80 to 90% of UTI in children. The symptoms and signs are nonspecific throughout infancy. Unexplained fever is the most common symptom of UTI during the first two years of life. After the second year of life, symptoms and signs of pyelonephritis include fever, chills, rigor, flank pain, and costovertebral angle tenderness. Lower tract symptoms and signs include suprapubic pain, dysuria, urinary frequency, urgency, cloudy urine, malodorous urine, and suprapubic tenderness. A urinalysis and urine culture should be performed when UTI is suspected. In the work-up of children with UTI, physicians must judiciously utilize imaging studies to minimize exposure of children to radiation. While waiting for the culture results, prompt antibiotic therapy is indicated for symptomatic UTI based on clinical findings and positive urinalysis to eradicate the infection and improve clinical outcome. The choice of antibiotics should take into consideration local data on antibiotic resistance patterns. Recent patents related to the management of UTI are discussed.

CONCLUSION

Currently, a second or third generation cephalosporin and amoxicillin-clavulanate are drugs of choice in the treatment of acute uncomplicated UTI. Parenteral antibiotic therapy is recommended for infants ≤ 2 months and any child who is toxic-looking, hemodynamically unstable, immunocompromised, unable to tolerate oral medication, or not responding to oral medication. A combination of intravenous ampicillin and intravenous/intramuscular gentamycin or a third-generation cephalosporin can be used in those situations. Routine antimicrobial prophylaxis is rarely justified, but continuous antimicrobial prophylaxis should be considered for children with frequent febrile UTI.

Pediatric Urinary Tract Infection as a Cause of Outpatient Clinic Visits in Southern Ethiopia: A Cross Sectional Study

Background

Failure to timely diagnose and treat urinary tract infections is associated with grave long term consequences. The objectives of this study included assessing the proportion and predictors of Urinary Tract Infection (UTI) as a cause of pediatric outpatient department (OPD) visits and determining common uropathogens with antimicrobial susceptibility pattern.

Methods

A cross sectional study was conducted from May to September 2015 among children of less than 15 years old at a tertiary center in Hawassa, Ethiopia. Children who fulfilled predefined eligibility criteria were recruited to undergo urine culture and urine analysis.

Results

A total of 863 children visited the OPD during the study period among which 269(31.2%) fulfilled the predefined eligibility criteria. Urine culture was positive for 74/269(27.5%) of the clinically suspected children. Male uncircumcision (adjusted odds ratio (aOR) 3.70; 95% CI 1.34–10.16) and under nutrition (aOR 5.41; 95%CI 2.64–11.07) were independent predictors of culture positivity. More than 5 WBC per high power field (aOR 4.7, 95% CI 1.8–12.7) on microscopy, urine PH > 5.0 (aOR 2.6, 95%CI 1.2–5.8), and positive leukocyte esterase (aOR 9.9, 95%CI 4.1–25.7) independently predicted positive growth on urine culture. Escherichia coli (34/74, 45.9%) and Klebsiella spp (18/74, 24.3%) were the most frequent isolates. High resistance was noted against amoxicillin (70.6%) and cotrimoxazole (97.1%) by E. coli.

Conclusion

UTI accounted for a tenth of total OPD visits. Commonly used first line antibiotics showed high level resistance to common etiologies of UTI. UTI should be suspected in febrile children, and antibiograms should be done to tailor prescription of antibiotics.

Prevalence and antimicrobial sensitivity pattern of urinary tract infection among children with cerebral palsy, Moshi, Tanzania

Background

Urinary tract infection (UTI) in children with cerebral palsy (CP) is a challenging yet common clinical condition. Children with CP bare the greatest risk of contracting UTI because of their difficulties in neuromotor control which lead to delay of bladder control, causing incomplete bladder emptying and urine retention.

Method

This was an analytical cross-sectional study that was conducted from September 2016 to March 2017 at Comprehensive Community Based Rehabilitation in Tanzania – Moshi and Kilimanjaro Christian Medical Centre Neurological Pediatrics Outpatient Clinic. All children who met the inclusion criteria were studied. Urine samples were collected at one point by catheterization, and urine dipstick and urine culture were done. Data were analyzed using SPSS version 20.

Results

A total of 99 children were enrolled in the study. The median age was 4 years (3–8 years); 53.5% were aged between 2 and 4 years. More than half were male. UTI was detected in 13.1% (n=13) of the children. Five causative agents of UTI were isolated, namely Escherichia coli, Proteus mirabilis, Klebsiella pneumonia, Staphylococcus aureus, and Enterococcus faecalis. The two most common organisms, E. coli and P. mirabilis, both had low sensitivity to ampicillin and co-trimoxazole while they were sensitive to ciprofloxacin and ceftriaxone.

Conclusion

UTI is a common finding among children with CP. E. coli and P. mirabilis are the commonest causative agents and are sensitive to ciprofloxacin and ceftriaxone but have low sensitivity to ampicillin and co-trimoxazole.

7-day compared with 10-day antibiotic treatment for febrile urinary tract infections in children: protocol of a randomised controlled trial

INTRODUCTION

The optimal duration of antibiotic therapy in children with febrile urinary tract infections (UTIs) is still a matter of debate. Current guidelines recommend treating children with febrile UTIs with antimicrobials for 7 to 14 days. We aim to compare the efficacy and safety of 7-day versus 10-day course of oral or sequence therapy (intravenous with a switch to oral) with cefuroxime/cefuroxime axetil for febrile UTIs in children.

METHODS AND ANALYSIS

A non-inferiority, double-blind, randomised, controlled trial will be conducted. Two hundred twenty-one patients aged 3 months to 7 years with febrile UTIs (defined as a combination of fever and leucocyturia in urine sediment) will be randomly assigned to a 7-day treatment arm (7 days of cefuroxime/cefuroxime axetil followed by 3 days of blinded placebo) or a 10-day treatment arm (7 days of cefuroxime/cefuroxime axetil followed by 3 days of blinded cefuroxime axetil). The primary outcome measure will be frequencies of recurrence and reinfection of UTI during the 6 months after the intervention.

ETHICS AND DISSEMINATION

The Bioethics Committee approved the study protocol. The findings of this trial will be submitted to a peer-reviewed paediatric journal. Abstracts will be submitted to relevant national and international conferences.

DATE AND PROTOCOL VERSION IDENTIFIER

04/09/2017 TRIAL REGISTRATION NUMBER: NCT03221504.

Urinary Tract Infection Antibiotic Trial Study Design: A Systematic Review

CONTEXT

Urinary tract infections (UTIs) represent common bacterial infections in children. No guidance on the conduct of pediatric febrile UTI clinical trials (CTs) exist.

OBJECTIVE

To assess the criteria used for patient selection and the efficacy end points in febrile pediatric UTI CTs.

DATA SOURCES

Medline, Embase, Cochrane central databases, and clinicaltrials.gov were searched between January 1, 1990, and November 24, 2016.

STUDY SELECTION

We combined Medical Subject Headings terms and free-text terms for "urinary tract infections" and "therapeutics" and "clinical trials" in children (0-18 years), identifying 3086 articles.

DATA EXTRACTION

Two independent reviewers assessed study quality and performed data extraction.

RESULTS

We included 40 CTs in which a total of 4381 cases of pediatric UTIs were investigated. Positive urine culture results and fever were the most common inclusion criteria (93% and 78%, respectively). Urine sampling method, pyuria, and colony thresholds were highly variable. Clinical and microbiological end points were assessed in 88% and 93% of the studies, respectively. Timing for end point assessment was highly variable, and only 3 studies (17%) out of the 18 performed after the Food and Drug Administration 1998 guidance publication assessed primary and secondary end points consistently with this guidance.

LIMITATIONS

Our limitations included a mixed population of healthy children and children with an underlying condition. In 6 trials, researchers studied a subgroup of patients with afebrile UTI.

CONCLUSIONS

We observed a wide variability in the microbiological inclusion criteria and the timing for end point assessment. The available guidance for adults appear not to be used by pediatricians and do not seem applicable to the childhood UTI. A harmonized design for pediatric UTIs CT is necessary.

Lidocaine Gel for Urethral Catheterization in Children: A Meta-Analysis

OBJECTIVE

To compare the efficacy and safety of lidocaine gel vs nonanesthetic gel (NAG) in reducing transurethral bladder catheterization (TUBC) procedural pain in children.

STUDY DESIGN

A systematic literature search was done using electronic medical databases and trial registries up to September 2016 with no language restrictions. Randomized controlled trials (RCTs) that assessed the efficacy and safety of lidocaine gel vs NAG in reducing TUBC-associated pain in children were screened, identified, and appraised. Risks of bias and study quality of the eligible trials were assessed according to the Cochrane Collaboration recommendations. Various pain assessment scales from the included studies were extracted as mean differences and standard deviations for each treatment group. Standardized mean differences (SMDs) were generated with 95% CIs for between-group difference estimation. Effect estimates were pooled using the inverse variance method with a random-effects model. Subgroup analysis was performed for different age groups.

RESULTS

Five RCTs (with a total of 369 children) were included. Overall pooled effect estimates showed that compared with NAG, lidocaine gel has no significant benefit in decreasing TUBC-associated pain in children (SMD, -0.22; 95% CI, -0.65 to 0.21). Effect estimates from 4 studies revealed no difference in pain reduction between the lidocaine gel and NAG in children aged <4 years (SMD, 0.01; 95% CI, -0.22 to 0.24). No serious adverse events from the lidocaine gel use were reported in any of the studies.

CONCLUSIONS

Lidocaine gel does not appear to reduce TUBC pain compared with NAG, specifically in children aged <4 years.

PROSPERO REGISTRATION NUMBER

CRD42016050018.

The clinical diagnosis and management of urinary tract infections in children and adolescents

Urinary tract infections (UTI) are one of the most common and serious bacterial infections encountered by paediatricians and primary care physicians. Although the diagnosis and management of UTI appear simplistic, they remain among the most contentious issues in paediatrics. In part, UTI controversies stem from the absence of classic clinical symptoms, inappropriate urine specimen collection, modified urinary tract imaging recommendations, and diverse treatment and prevention strategies. 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 paediatric and adolescent populations.

The urinary and serum levels of IL-32 in children with febrile urinary tract infections

Aim

We assessed the urinary and serum levels of IL-32 in pediatric patients with acute pyelonephritis (APN) with and without renal scarring.

Results

We enrolled children aged 2 months to 16 years with APN. Dimercaptosuccinic acid scans and ultrasonography studies were ordered for all patients, and a voiding. A total of 86 children (aged 57 ± 39 months, 74 [86%] female) were enrolled in this study. Group 1 was composed of 19 (16 female) patients, group 2 of 38 (35 female) patients and group 3 of 29 (23 female) patients. There were no significant differences in the serum and absolute urinary levels of IL-32 (UIL-32) between groups, but the urinary IL-32/creatinine ratio (UIL-32/Cr) was significantly higher in children with pyelonephritis than controls.

An Overview of Two-Component Signal Transduction Systems Implicated in Extra-Intestinal Pathogenic E. coli Infections

Extra-intestinal pathogenic E. coli (ExPEC) infections are common in mammals and birds. The predominant ExPEC types are avian pathogenic E. coli (APEC), neonatal meningitis causing E. coli/meningitis associated E. coli (NMEC/MAEC), and uropathogenic E. coli (UPEC). Many reviews have described current knowledge on ExPEC infection strategies and virulence factors, especially for UPEC. However, surprisingly little has been reported on the regulatory modules that have been identified as critical in ExPEC pathogenesis. Two-component systems (TCSs) comprise the predominant method by which bacteria respond to changing environments and play significant roles in modulating bacterial fitness in diverse niches. Recent studies have highlighted the potential of manipulating signal transduction systems as a means to chemically re-wire bacterial pathogens, thereby reducing selective pressure and avoiding the emergence of antibiotic resistance. This review begins by providing a brief introduction to characterized infection strategies and common virulence factors among APEC, NMEC, and UPEC and continues with a comprehensive overview of two-component signal transduction networks that have been shown to influence ExPEC pathogenesis.

Inflammation drives renal scarring in experimental pyelonephritis

Acquired renal scarring occurs in a subset of patients following febrile urinary tract infections and is associated with hypertension, proteinuria, and chronic kidney disease. Limited knowledge of histopathology, immune cell recruitment, and gene expression changes during pyelonephritis restricts the development of therapies to limit renal scarring. Here, we address this knowledge gap using immunocompetent mice with vesicoureteral reflux. Transurethral inoculation of uropathogenic Escherichia coli in C3H/HeOuJ mice leads to renal mucosal injury, tubulointerstitial nephritis, and cortical fibrosis. The extent of fibrosis correlates most significantly with inflammation at 7 and 28 days postinfection. The recruitment of neutrophils and inflammatory macrophages to infected kidneys is proportional to renal bacterial burden. Transcriptome analysis reveals molecular signatures associated with renal ischemia-reperfusion injury, immune cell chemotaxis, and leukocyte activation. This murine model recapitulates the cardinal histopathological features observed in humans with acquired renal scarring following pyelonephritis. The integration of histopathology, quantification of cellular immune influx, and unbiased transcriptional profiling begins to define potential mechanisms of tissue injury during pyelonephritis in the context of an intact immune response. The clear relationship between inflammatory cell recruitment and fibrosis supports the hypothesis that acquired renal scarring arises as a consequence of excessive host inflammation and suggests that immunomodulatory therapies should be investigated to reduce renal scarring in patients with pyelonephritis.

Resistance to oral antibiotics in 4569 Gram-negative rods isolated from urinary tract infection in children

To investigate antibiotic resistance among pathogens isolated from urines in a tertiary care children's hospital in Italy. Retrospective analysis of prospectively collected data on antibiotic susceptibility of Gram-negatives isolated from urines at the Istituto Giannina Gaslini, Genoa - Italy from 2007 to 2014. Antibiotic susceptibility was evaluated. By means of CLSI criteria from 2007 to 2010, while from 2011 EUCAST criteria were adopted. Data on susceptibility to amoxicillin-clavulanate, co-trimoxazole, cefuroxime, nitrofurantoin, fosfomycin and ciprofloxacin were evaluated for Escherichia coli, while for other Enterobacteriaceae data were collected for amoxicillin-clavulanate, co-trimoxazole and ciprofloxacin and for ciprofloxacin against Pseudomonas aeruginosa. Univariate and multivariable analyses were performed for risk factors associated with resistance. A total of 4596 Gram-negative strains were observed in 3364 patients. A significant increase in the proportion of resistant strains was observed for E.coli against amoxicillin-clavulanate, cefuroxime and ciprofloxacin and for others Enterobacteriaceae against co-trimoxazole and ciprofloxacin. Resistance to nitrofurantoin and fosfomycin was very infrequent in E.coli. Logistic regression analysis showed that repeated episode of urinary tract infections was a risk factor for E.coli resistance to amoxicillin-clavulanate, co-trimoxazole and cefuroxime, while admission in one of the Units usually managing children with urinary tract malformations was significantly associated to resistance to amoxicillin-clavulanate and cefuroxime.

CONCLUSION

In conclusion the present study shows an increase in antibiotic resistance in pediatric bacteria isolated from urines in children, especially in presence of repeated episodes and/or urinary tract malformations. This resistance is worrisome for beta-lactams and cotrimoxazole, and start to increase also for fluoroquinolones while nitrofurantoin and fosfomycin still could represent useful drugs for oral treatment of these infections.

WHAT IS KNOWN

• Infections are frequent in patients with urinary tract malformations • Antibiotic prophylaxis can select for resistant pathogens What is New: • The increase in the resistance to β-lactams, co-trimoxazole or fluoroquinolones in pathogens causing urinary tract infections cause a reduction of drugs with oral formulations available for therapy • Old drugs like nitrofurantoin and fosfomycin can represent attractive compounds for oral treatment of urinary tract infections in children presence of resistance to other drug classes.

Preliminary study on serum paraoxonase-1 status and chemokine (C-C motif) ligand 2 in hospitalized elderly patients with catheter-associated asymptomatic bacteriuria

Urinary tract infections (UTI) are common among elderly patients in residential care facilities, as well as in the hospital setting. Identifying new biochemical markers of UTI is an active line of research since UTI management is resource intensive. Paraoxonase-1 (PON1) forms part of the patient's immune system, the response-to-injury and inflammation. Our study sought to evaluate alterations in inflammation-related paraoxonase-1 (PON1) and chemokine (C-C motif) ligand 2 (CCL2) in patients with an indwelling catheter to assess their potential usefulness as biomarkers of infection. Patients (n = 142) who had had the urinary catheter removed and 100 healthy volunteers were recruited. In all participants we measured serum PON1 activity, PON1 concentration, CCL2, procalcitonin and C-reactive protein (CRP). Results indicated that patients had higher CCL2, CRP and procalcitonin concentrations than the control group, and lower paraoxonase activity. There were no significant differences in PON1 concentrations. When comparing the diagnostic accuracy of CRP, procalcitonin, CCL2 and the PON1-related variables in discriminating between patients with and those without UTI, we found a considerable degree of overlap between groups, i.e., a low diagnostic accuracy. However, there were significant inverse logarithmic correlations between serum paraoxonase activity and the number of days the urinary catheter had been in situ. Our results suggest that measurement of these biochemical variables may be useful in investigating complications of long-term use of these devices and help to improve the economic and clinical investment required in the management of the often-associated infection.

Expression and Significance of the HIP/PAP and RegIIIγ Antimicrobial Peptides during Mammalian Urinary Tract Infection

Recent evidence indicates that antimicrobial peptides (AMPs) serve key roles in defending the urinary tract against invading uropathogens. To date, the individual contribution of AMPs to urinary tract host defense is not well defined. In this study, we identified Regenerating islet-derived 3 gamma (RegIIIγ) as the most transcriptionally up-regulated AMP in murine bladder transcriptomes following uropathogenic Escherichia coli (UPEC) infection. We confirmed induction of RegIIIγ mRNA during cystitis and pyelonephritis by quantitative RT-PCR. Immunoblotting demonstrates increased bladder and urinary RegIIIγ protein levels following UPEC infection. Immunostaining localizes RegIIIγ protein to urothelial cells of infected bladders and kidneys. Human patients with UTI have increased urine concentrations of the orthologous Hepatocarcinoma-Intestine-Pancreas / Pancreatitis Associated Protein (HIP/PAP) compared to healthy controls. Recombinant RegIIIγ protein does not demonstrate bactericidal activity toward UPEC in vitro, but does kill Staphylococcus saprophyticus in a dose-dependent manner. Kidney and bladder tissue from RegIIIγ knockout mice and wild-type mice contain comparable bacterial burden following UPEC and Gram-positive UTI. Our results demonstrate that RegIIIγ and HIP/PAP expression is induced during human and murine UTI. However, their specific function in the urinary tract remains uncertain.

Amplifying renal immunity: the role of antimicrobial peptides in pyelonephritis

Urinary tract infections (UTIs), including pyelonephritis, are among the most common and serious infections encountered in nephrology practice. UTI risk is increased in selected patient populations with renal and urinary tract disorders. As the prevalence of antibiotic-resistant uropathogens increases, novel and alternative treatment options will be needed to reduce UTI-associated morbidity. Discoveries over the past decade demonstrate a fundamental role for the innate immune system in protecting the urothelium from bacterial challenge. Antimicrobial peptides, an integral component of this urothelial innate immune system, demonstrate potent bactericidal activity toward uropathogens and might represent a novel class of UTI therapeutics. The urothelium of the bladder and the renal epithelium secrete antimicrobial peptides into the urinary stream. In the kidney, intercalated cells--a cell-type involved in acid-base homeostasis--have been shown to be an important source of antimicrobial peptides. Intercalated cells have therefore become the focus of new investigations to explore their function during pyelonephritis and their role in maintaining urinary tract sterility. This Review provides an overview of UTI pathogenesis in the upper and lower urinary tract. We describe the role of intercalated cells and the innate immune response in preventing UTI, specifically highlighting the role of antimicrobial peptides in maintaining urinary tract sterility.