Fever duration during treated urinary tract infections and development of permanent renal lesions

Evidence-based clinical practice guideline for management of urinary tract infection and primary vesicoureteric reflux

We present updated, evidence-based clinical practice guidelines from the Indian Society of Pediatric Nephrology (ISPN) for the management of urinary tract infection (UTI) and primary vesicoureteric reflux (VUR) in children. These guidelines conform to international standards; Institute of Medicine and AGREE checklists were used to ensure transparency, rigor, and thoroughness in the guideline development. In view of the robust methodology, these guidelines are applicable globally for the management of UTI and VUR. Seventeen recommendations and 18 clinical practice points have been formulated. Some of the key recommendations and practice points are as follows. Urine culture with > 104 colony forming units/mL is considered significant for the diagnosis of UTI in an infant if the clinical suspicion is strong. Urine leukocyte esterase and nitrite can be used as an alternative screening test to urine microscopy in a child with suspected UTI. Acute pyelonephritis can be treated with oral antibiotics in a non-toxic infant for 7-10 days. An acute-phase DMSA scan is not recommended in the evaluation of UTI. Micturating cystourethrography (MCU) is indicated in children with recurrent UTI, abnormal kidney ultrasound, and in patients below 2 years of age with non-E. coli UTI. Dimercaptosuccinic acid scan (DMSA scan) is indicated only in children with recurrent UTI and high-grade (3-5) VUR. Antibiotic prophylaxis is not indicated in children with a normal urinary tract after UTI. Prophylaxis is recommended to prevent UTI in children with bladder bowel dysfunction (BBD) and those with high-grade VUR. In children with VUR, prophylaxis should be stopped if the child is toilet trained, free of BBD, and has not had a UTI in the last 1 year. Surgical intervention in high-grade VUR can be considered for parental preference over antibiotic prophylaxis or in children developing recurrent breakthrough febrile UTIs on antibiotic prophylaxis.

Host RNA Expression Signatures in Young Infants with Urinary Tract Infection: A Prospective Study

Early diagnosis of infections in young infants remains a clinical challenge. Young infants are particularly vulnerable to infection, and it is often difficult to clinically distinguish between bacterial and viral infections. Urinary tract infection (UTI) is the most common bacterial infection in young infants, and the incidence of associated bacteremia has decreased in the recent decades. Host RNA expression signatures have shown great promise for distinguishing bacterial from viral infections in young infants. This prospective study included 121 young infants admitted to four pediatric emergency care departments in the capital region of Denmark due to symptoms of infection. We collected whole blood samples and performed differential gene expression analysis. Further, we tested the classification performance of a two-gene host RNA expression signature approaching clinical implementation. Several genes were differentially expressed between young infants with UTI without bacteremia and viral infection. However, limited immunological response was detected in UTI without bacteremia compared to a more pronounced response in viral infection. The performance of the two-gene signature was limited, especially in cases of UTI without bloodstream involvement. Our results indicate a need for further investigation and consideration of UTI in young infants before implementing host RNA expression signatures in clinical practice.

Individualised versus standard duration of antibiotic therapy in children with acute uncomplicated febrile urinary tract infection: a study protocol and statistical analysis plan for a multicentre randomised clinical trial

INTRODUCTION

Febrile urinary tract infection is one of the most common bacterial infections in children. Currently, recommended antibiotic duration is 10 days. However, recent evidence suggests that 90%-95% of children with febrile urinary tract infections are afebrile and clinically improved 48-72 hours after treatment initiation. Accordingly, individualised duration of antibiotic therapy, according to the recovery time, might be more beneficial than current recommendations, but no evidence exists.

METHODS AND ANALYSIS

An open-label randomised clinical trial equally randomising children aged 3 months to 12 years from eight Danish paediatric departments with uncomplicated febrile (≥38°C) urinary tract infection to either individualised or standard duration of antibiotic therapy. Children allocated to individualised duration of antibiotic therapy will terminate antibiotic therapy 3 days after clinical improvement with no fever, flank pain or dysuria. Children allocated to standard duration will receive 10 days of antibiotic therapy. Co-primary outcomes are non-inferiority for recurrent urinary tract infection or death within 28 days after the end of treatment (non-inferiority margin 7.5 percentage points) and superiority for the number of days with antibiotic therapy within 28 days after treatment initiation. Seven other outcomes will also be assessed. A total of 408 participants are needed to detect non-inferiority (one-sided alpha 2.5%; beta 80%).

ETHICS AND DISSEMINATION

This trial has been approved by the Ethics Committee (H-21057310) and the Data Protection Agency (P-2022-68) in Denmark. Regardless of the trial's findings (whether positive, negative or inconclusive), the results will be compiled into one or more manuscripts for publication in international peer-reviewed scientific journals and presented at conferences.

TRIAL REGISTRATION NUMBER

NCT05301023.

Cases of Pediatric Pyelonephritis: A Single-Center Retrospective Study from an Extended-Spectrum β-Lactamase-Producing Escherichia coli Endemic Area in Japan

Background

Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli has been increasingly recognized as the cause of upper urinary tract infection (UTI) in children. We have been using flomoxef at our department since 2017 as the first-line empiric therapy for children diagnosed with UTIs, and we avoid using carbapenems, which are considered the first-line treatment for ESBL-producing E. coli. However, reports on the use of flomoxef for UTIs are limited, especially for pediatric patients. The presence of vesicoureteral reflux at the onset of pyelonephritis is a concern. Severe vesicoureteral reflux can lead to repeated UTI and future deterioration of renal function, but the indication for voiding urethrography, which closely examines the presence of vesicoureteral reflux complications, is controversial.

Methods

We retrospectively reviewed the laboratory findings, treatment, and clinical course of 96 pyelonephritis cases experienced at our department over a 7-year period from April 2014 to March 2021.

Results

ESBL-producing E. coli were identified as the cause of pyelonephritis in 51% of cases, and this value was significantly higher (88%) in 2017. No significant differences were found in the febrile period or recurrence rate between the flomoxef-initiated group and other antibiotics groups. We also examined clinical indicators to predict vesicoureteral reflux and found no significant differences in ultrasonographic findings of hydronephrosis.

Conclusion

In the present series, 51% of all pyelonephritis cases were found to be caused by ESBL-producing E. coli, with a significant increase in recent years. Flomoxef may be a useful alternative to carbapenem for ESBL-producing E. coli and the initial antibiotic of choice for upper UTIs in children. The indication for voiding cystourethrography should be carefully determined.

Contemporary Management of Urinary Tract Infections in Children

Purpose of Review

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

Recent Findings

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

Summary

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

The Direct Semi-Quantitative Detection of 18 Pathogens and Simultaneous Screening for Nine Resistance Genes in Clinical Urine Samples by a High-Throughput Multiplex Genetic Detection System

Background

Urinary tract infections (UTIs) are one the most common infections. The rapid and accurate identification of uropathogens, and the determination of antimicrobial susceptibility, are essential aspects of the management of UTIs. However, existing detection methods are associated with certain limitations. In this study, a new urinary tract infection high-throughput multiplex genetic detection system (UTI-HMGS) was developed for the semi-quantitative detection of 18 pathogens and the simultaneously screening of nine resistance genes directly from the clinical urine sample within 4 hours.

Methods

We designed and optimized a multiplex polymerase chain reaction (PCR) involving fluorescent dye-labeled specific primers to detect 18 pathogens and nine resistance genes. The specificity of the UTI-HMGS was tested using standard strains or plasmids for each gene target. The sensitivity of the UTI-HMGS assay was tested by the detection of serial tenfold dilutions of plasmids or simulated positive urine samples. We also collected clinical urine samples and used these to perform urine culture and antimicrobial susceptibility testing (AST). Finally, all urine samples were detected by UTI-HMGS and the results were compared with both urine culture and Sanger sequencing.

Results

UTI-HMGS showed high levels of sensitivity and specificity for the detection of uropathogens when compared with culture and sequencing. In addition, ten species of bacteria and three species of fungi were detected semi-quantitatively to allow accurate discrimination of significant bacteriuria and candiduria. The sensitivity of the UTI-HMGS for the all the target genes could reach 50 copies per reaction. In total, 531 urine samples were collected and analyzed by UTI-HMGS, which exhibited high levels of sensitivity and specificity for the detection of uropathogens and resistance genes when compared with Sanger sequencing. The results from UTI-HMGS showed that the detection rates of 15 pathogens were significantly higher (P<0.05) than that of the culture method. In addition, there were 41(7.72%, 41/531) urine samples were positive for difficult-to-culture pathogens, which were missed detected by routine culture method.

Conclusions

UTI-HMGS proved to be an efficient method for the direct semi-quantitative detection of 18 uropathogens and the simultaneously screening of nine antibiotic resistance genes in urine samples. The UTI-HMGS could represent an alternative method for the clinical detection and monitoring of antibiotic resistance.

In children with urinary tract infection reduced kidney length and vesicoureteric reflux predict abnormal DMSA scan

BACKGROUND

To evaluate sensitivity, specificity, and positive and negative predictive values (PPV and NPV, respectively) of renal ultrasonography (US) in predicting renal uptake defects or reduced renal function at Tc-99m dimercaptosuccinic acid (DMSA) scan (primary outcome). We also evaluated which factors could be associated with Tc-99m DMSA renal scan anomalies.

METHODS

We retrospectively included all the patients with vesico-ureteral reflux (VUR) undergoing the first Tc-99m DMSA renal scan within 3 months from the most recent renal US between 2016 and 2018.

RESULTS

Sensitivity, specificity, PPV, and NPV of US in predicting abnormal Tc-99m DMSA scan were 38.9%, 91.5%, 71.9%, and 72.9%, respectively. Different length between the kidneys, expressed as standard deviation score (SDS), showed an area under the receiver operating characteristic curve of 0.70 (95% CI, 0.60-0.80; p < 0.0001) when evaluated as predictor of abnormal Tc-99m DMSA scan. A different length between the two kidneys >1.11 SDS had 91.5% sensitivity and 57.6% specificity. At multivariate analysis, the factors with significantly increased odds ratio of abnormal Tc-99m DMSA scan were difference in length between two kidneys >1.11 SDS and dilated VUR.

CONCLUSIONS

The Tc-99m DMSA scan remains the gold standard to detect renal parenchymal anomalies. A different length between the kidneys >1.11 SDS and dilated VUR are predictors of abnormal Tc-99m DMSA renal scan.