Voiding cystourethrograms and urinary tract infections: how long to wait?

National Trends in Voiding Cystourethrograms During Hospitalization for Young Infants With Urinary Tract Infections

OBJECTIVES

The American Academy of Pediatrics published a guideline in 2011 recommending against the routine use of voiding cystourethrogram (VCUG) in infants aged 2 to 24 months with first febrile urinary tract infection (UTI); however, the rates of VCUG for infants aged <2 months are unknown. The objective of this study was to determine the trend in VCUG performance during index hospitalization among infants aged 0 to 2 months with UTI.

METHODS

This retrospective cohort study included infants aged birth to 2 months hospitalized with a UTI from 2008 to 2019 across 38 institutions in the Pediatric Health Information System. Outcome measures included recurrent UTI within 1 year, vesicoureteral reflux diagnosis within 1 year and antiurinary reflux procedure performed within 2 years. Trends over time were compared between preguideline (2008-2011) and postguideline periods (2012-2019) using piecewise mixed-effects logistic regression.

RESULTS

The odds of VCUG decreased by 21% per year in the preguideline period (adjusted odds ratio, 0.79; 95% confidence interval, 0.77-0.81; P < .001) versus 20% (adjusted odds ratio, 0.80; 95% confidence interval, 0.77-0.83; P < .001) in the postguideline period. The preguideline and postguideline difference was not statistically significant (P = .60). There was no difference in the postguideline odds of UTI within 1 year (P = .07), whereas the odds of vesicoureteral reflux diagnosis (P < .001) and antiurinary reflux procedure performance (P < .001) decreased.

CONCLUSIONS

VCUG performance during hospitalization has declined over the past decade among young infants hospitalized with UTI. Further work is needed to determine the optimal approach to imaging in these young infants.

Culture-positive urinary tract infection following micturating cystourethrogram in children

Objective

To determine the incidence of culture-positive urinary tract infection (UTI) after micturating cystourethrogram (MCUG). We further wanted to identify risk factors for developing a culture-positive UTI following MCUG.

Methods

A retrospective review of the available medical records of 500 paediatric patients who underwent MCUG in Perth, Western Australia was performed.

Results

Seven (1.4%) patients comprised of four females and three males developed a febrile, culture-positive UTI within 14 days following MCUG. Significant association was found for female patients, patients with neurogenic bladder, and patients with previous culture-positive UTI as developing a culture-positive UTI following MCUG. Multivariate logistic regression determined that patients were more likely to develop culture-positive UTI within 14 days following MCUG if they had a known history of UTI (odds ratio: 5.0, 95% confidence interval: 1.5–17.3, p=0.010) or had a neurogenic bladder (odds ratio: 4.2, 95% confidence interval: 1.0–17.9, p=0.049).

Conclusion

The incidence of patients who developed a febrile, culture-positive UTI following MCUG was low at 1.4%. Statistically significant and independent associations for the development of culture positive UTI were found in patients with neurogenic bladder and patients with previous culture-positive UTI. Further prospective studies are necessary to determine necessity of prophylactic antibiotics for high-risk patients, e.g., patients with neurogenic bladder or previous culture-positive UTI.

Predictive score for vesicoureteral reflux in children with a first febrile urinary tract infection

OBJECTIVE

To develop a simple score for predicting vesicoureteral reflux after a first febrile urinary tract infection in children.

METHODS

A retrospective cohort study was conducted for a 12-year period (January 2008 to December 2019), including patients aged <72 months who underwent renal ultrasonography and voiding cystourethrography after a first febrile urinary tract infection. Patients with a history of antenatal hydronephrosis were excluded. The prediction model and score for vesicoureteral reflux were developed using multivariate logistic regression analysis.

RESULTS

Out of 260 patients in total (median age 4 months, 172 boys), 41 (16%) had vesicoureteral reflux. The score was based on four independent risk factors, including age >6 months (odds ratio 2.71, 95% confidence interval 1.27-5.76), presence of sepsis (odds ratio 3.44, 95% confidence interval 1.31-9.04), white blood cell count ≥15 000/mm³ (odds ratio 1.83, 95% confidence interval 0.88-3.8) and abnormal renal ultrasonography results (odds ratio 2.08, 95% confidence interval 1-4.31). A lower probability of vesicoureteral reflux (positive likelihood ratio = 0.66; P = 0.001) was found in the low-risk group (scores 0-2), whereas a higher probability of vesicoureteral reflux (positive likelihood ratio = 2.54; P = 0.001) was found in the high-risk group (scores 3-5). The predictive ability of the model was 70%.

CONCLUSIONS

The scores developed based on the patient characteristics and renal ultrasonography are useful in predicting presence of vesicoureteral reflux after a first febrile urinary tract infection in children and could guide clinicians' decisions to perform additional imaging studies.

Clinical Predictors for Abnormal Renal Bladder Ultrasound in Hospitalized Young Children With a First Febrile Urinary Tract Infection

BACKGROUND

Physicians often obtain a routine renal bladder ultrasound (RBUS) for young children with a first febrile urinary tract infection (UTI). However, few children are diagnosed with serious anatomic anomalies, and opportunity may exist to take a focused approach to ultrasonography. We aimed to identify characteristics of the child, prenatal ultrasound (PNUS), and illness that could be used to predict an abnormal RBUS and measure the impact of RBUS on management.

METHODS

We conducted a single-center prospective cohort study of hospitalized children 0 to 24 months of age with a first febrile UTI from October 1, 2016, to December 23, 2018. Independent variables included characteristics of the child, PNUS, and illness. The primary outcome, abnormal RBUS, was defined through consensus of a multidisciplinary team on the severity of ultrasound findings important to identify during a first UTI.

RESULTS

A total of 211 children were included; the median age was 1.0 month (interquartile range 0-2), and 55% were uncircumcised boys. All mothers had a PNUS with 10% being abnormal. Escherichia coli was the pathogen in 85% of UTIs, 20% (n = 39 of 197) had bacteremia, and 7% required intensive care. Abnormal RBUS was found in 36% (n = 76 of 211) of children; of these, 47% (n = 36 of 76) had moderately severe findings and 53% (n = 40 of 76) had severe findings. No significant difference in clinical characteristics was seen among children with and without an abnormal RBUS. One child had Foley catheter placement, and 33% received voiding cystourethrograms, 15% antibiotic prophylaxis, and 16% subspecialty referrals.

CONCLUSIONS

No clinical predictors were identified to support a focused approach to RBUS examinations. Future studies should investigate the optimal timing for RBUS.

Timing of voiding cystourethrography after febrile urinary tract infection in children: a systematic review

BACKGROUND

Despite a trend towards early voiding cystourethrography (VCUG) after febrile urinary tract infection (fUTI) in children, clinical guidelines do not comment on the optimal timing and current practice varies considerably.

OBJECTIVE

To assess whether the detection rate of vesicoureteric reflux (VUR) in children depends on the time period of VCUG procedure after onset of antibiotic therapy.

METHODS

MEDLINE, EMBASE and Cochrane Controlled Trials Register electronic databases were searched for eligible studies without language or time restriction (19 November 2018). Inclusion criteria were (1) patients <18 years of age; (2) VCUG performed in patients with fUTI after onset of antibiotic therapy either in the same patient population or in two or more different patient populations within one study at different time periods; and (3) with reported detection rate of VUR. The systematic review was carried out following the recommendations of the Cochrane Collaboration and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS

Of 4175 records, nine studies were included (number of patients, n=1745) for the main outcome prevalence of VUR by VCUG <8 days compared with VCUG ≥8 days after onset of antibiotic therapy. Pooled overall prevalence of VUR was not significantly different between the early and the late VCUG groups (risk ratio 0.98, 95% CI 0.81 to 1.19). Prevalence of VUR stratified by grade was not significantly different between the two groups.

CONCLUSION

Early VCUG within 8 days after onset of antibiotic therapy does not affect the prevalence of VUR.

TRIAL REGISTRATION NUMBER

CRD42018117545.

Vesicoureteral Reflux and Renal Scarring in Infants After the First Febrile Urinary Tract Infection

Introduction

The objective of this research was to determine whether vesicoureteral reflux(VUR) was associated with evolution to renal scarring (RS) following a febrile urinary tract infection (UTI) in infants.

Materials and methods

Our research included 100 infants, ages up to 1 year with a first febrile UTI. The diagnostic was based on results of: laboratory findings, ultrasonography (USG), voiding cystourethrography (VCUG) and initial and control renal scintigraphy (DMSA renal scan) withtechnetium^99mTcsuccimer (dimercaptosuccinic acid), to assess the acute pyelonephritis (APN), VUR and RS.

Results

APN was proven with DMSA renal scan in 66 (66%) infants. Twenty-two infants (33.3%) had VUR in-group of patients with APN. On the control DMSA scan, performed 6 months after the first DMSA, the presence of RS was found in 18 (27.27%) infants. In infants with renal scars VUR were discovered in 9 of them (50%).

Conclusions

The pathogenesis of RS after febrile UTI in young children is multifactorial. Children with VUR have an increased risk for APN and RS. However, VUR is not the only precondition for RS. Creating a renal scarring cannot be imagined without the inflammatory process of the upper urinary system. Therefore, early detection and treatment of febrile UTIs in children and identify children at risk for RS are of primary importance.

Influence of Plasminogen Activator Inhibitor -1 Gene Polymorphism on Renal Scarring After First Febrile Urinary Tract Infection in Infants

Background

The pathogenesis of renal scarring (RS) after first febrile urinary tract infection (UTI) in children is multifactorial. In addition to well-known risk factors, a role for genetic predisposition has been suggested.

Aims

To determine whether deoxyribonucleic acid (DNA) polymorphisms at the plasminogen activator inhibitor -1 (PAI-1) gene were associated with evolution to RS following a febrile UTI in infants.

Materials and Methods

Our research included 100 infants, 84 girls and 16 boys, ages up to 1 year with a first febrile UTI, increased inflammatory parameters and positive urine culture treated at the Pediatric Clinic II of the University Clinical Center Sarajevo (UCCS). The diagnostic was based on the imaging studies: ultrasonography, voiding cystourethrography (VCUG) and initial and control static renal scintigraphy (DMSA renal scan), to assess the renal parenchymal damage (RPD). The polymorphisms of the PAI-1 were determined based on polymerase chain reaction technique. The distribution of PAI-1 genotypes and the allele frequencies were compared between different groups of patients with febrile UTI.

Results

Results presented that 66 infants had acute pyelonephritis (APN) and 22 had vesicoureteral reflux (VUR). On initial DMSA renal scan examination, we detected no RPD in any patient. After 6 months, the repeat DMSA renal scan revealed the presence of RPD in 18 (27%) out of 66 infants with APN. Distribution of PAI-1 genotypes was not different between various groups of patients with febrile UTI.

Conclusions

The results of our study have not shown that individual genetic variation in PAI-1 is an independent variable that predispose same of children for RS after first febrile UTI. Maybe that yet unknown gene polymorphisms together with geographical and /or socio-economic differences can influence on the development of RS.

Voiding cystourethrogram: How much should we be selective?

OBJECTIVE

In this study, we examined the patients' characteristics, who underwent voiding cystourethrography (VCUG), in order to determine any selectivity for indication of this invasive method.

MATERIAL AND METHODS

After exclusion of indications of neurogenic bladder or antenatal hydronephrosis and control VCUGs, 159 VCUGs performed in our clinic within one year were evaluated. Patients are divided into three groups accoding to age. Clinical characteristic and findings of renal ultrasonography (US) and renal scintigraphy were examined.

RESULTS

Vesicoureteral reflux (VUR) was detected in 61 (38.3%) of 159 patients who underwent cystourethrographic examinations, in 45.8% of the patients with a history of recurrent urinary tract infection (UTI), in 22.0% of the patients with pathological urinary system US without history of recurrent UTI. High-grade reflux rate was significantly more frequent in renal units with pathological US findings. Severe scar was significantly more frequent in renal units with high-grade reflux when compared to renal units without reflux and those with low-grade reflux. Predictive values of recurrent UTI, scarring status and pathological US for VUR were separately analyzed and seen that likelihood of indicating VUR was increased when all 3 risk factors were assessed together.

CONCLUSION

Vesicoureteral reflux is a problem in which diagnostic process and management strategy should have to be considered in individualized manner for each patient. Before prescribing invasive VCUG, imaging urinary system by US and scintigraphy and determining whether there is recurrent UTI will improve selectivity and success of VCUG.

Comparing between results and complications of doing voiding cystourethrogram in the first week following urinary tract infection and in 2-6 weeks after urinary tract infection in children referring to a teaching hospital

Introduction: Urinary tract infection is the most common genitourinary disease in children so about 40% of the children with urinary tract infection suffering from reflux that caused some consequences such as pyelonephritis and kidney parenchymal injury.

Objectives: This research was conducted to compare the timing of voiding cystourethrogram (VCUG) in children with urinary tract infection in first week and after the first week of urinary tract infection.

Patients and Methods: This research is a case-control study that both case and control groups include 208 children from 1 month to 12 years old with the complain of urinary tract infection. In case group, the VCUG was performed at the first week of infection and in control group, the VCUG was performed after the first week of infection.

Results: complication such as dysuria was observed in two-thirds of children who VCUG was performed during first week after urinary tract infection. Parents stress in case group was more than the other (P=0.015). For overall, the incidence of reflux in case and control groups was 49.5% and 50%, respectively. The mean of reflux grading in right kidney in case group was lower than control group resulting in significant differences between two groups.

Conclusion: According to higher grade of stress in parents and complications due to VCUG at the first week of urinary tract infection, it is suggested that VCUG be conducted on selective patients in the hospital at the first week of urinary tract infection and during hospitalization.

Significance of Sonographically Demonstrated Ureteral Dilatation in Evaluation of Vesicoureteral Reflux Verified with Voiding Urosonography in Children with Urinary Tract Infection

Objectives:

The aim of this study was to determine sensitivity, specificity, and predictive values of sonographically demonstrated ureteral dilatation in detecting vesicoureteral reflux (VUR).

Methods:

Ethical approval from the Ethical Committee of Clinical Center University of Sarajevo and parental consent were obtained for this prospective study involving 120 children with history of urinary tract infections (UTIs). Ultrasound examination included the evaluation of the urinary tract, with a special emphasis on evaluation of ureteral dilatation. Voiding urosonography (VUS) was carried out according to a standard protocol with the use of ultrasound contrast agent Sono Vue of second generation. Ureteral diameter greater than 3 mm was considered pathological. Proven VUR was graded into one of three stages.

Results:

Infectio tracti urinarii recidivans was referral diagnosis in the majority of patients. The average age of patients was 4.33 ± 3.88 years (from 2 months to 16 years of age). VUS findings were normal in 59 (49.2%), and pathological in 61 (50.8%) patients. Statistical analysis showed significant correlation between type and grade of VUR. Our data confirmed predominance of VUR in females and in children under the age of 5. Statistically significant correlation between ureteral dilatation and the existence of VUR was found, with relatively high sensitivity (67.2%), specificity (81.4%), and high positive (78.8%) and negative predictive value (70.6%), total diagnostic accuracy of 74.2% in detecting VUR, and significantly increased probability (20 – 25%) of detecting VUR in patients with sonographically confirmed ureteral dilatation.

Conclusion:

Sonographically confirmed ureteral dilatation can be used as a predictor of VUR in children with UTIs, and in combination with other predictors, might find a place in an evidence-based selective strategy in children with suspected VUR.

The RIVUR trial: profile and baseline clinical associations of children with vesicoureteral reflux

BACKGROUND AND OBJECTIVE

Vesicoureteral reflux (VUR) is diagnosed in ∼30% to 40% of children who have imaging studies after urinary tract infections (UTIs). Our goal is to characterize children enrolled in the Randomized Intervention for Children with Vesicoureteral Reflux (RIVUR) trial and to compare our study cohort with those from previously published studies.

METHODS

RIVUR investigators from 19 pediatric sites in the United States recruited 607 children with grade I through IV VUR. Children were enrolled after a first or second UTI. This cross-sectional report of baseline data includes extensive clinical, parental report, and imaging study results.

RESULTS

RIVUR recruited 607 children (558 girls, 49 boys) with grade I (11%), II (42%), III (38%), or IV (8%) reflux. The median age was 12 months, and most children (91%) were enrolled after their first UTI. The UTI leading to enrollment was both febrile and symptomatic for 323 children, febrile only in 197 children, and symptomatic only in 86. Renal involvement at baseline as documented by a (99m)Tc dimercaptosuccinic acid scan was uncommon with cortical defects identified in 89 (15%) children. Bladder and bowel dysfunction was identified in 71 (56%) of 126 toilet-trained subjects assessed.

CONCLUSIONS

RIVUR is the largest prospective, randomized trial for children with primary VUR to date, comparing prophylaxis with placebo. The study sample comprises patients from 19 pediatric clinical sites in the United States, whose demographic and clinical characteristics may differ from those of children enrolled in previous trials from other countries.

[Diagnostics and therapy of urinary tract infections]

In infants and young children, urinary tract infections (UTI) often present with unspecific symptoms. Appropriate techniques of urine sampling play an important role for accurate microbiological diagnosis. In infants urine sampling by bladder puncture or transurethral catheter is recommended. In young infants with suspected pyelonephritis, calculated antibiotic treatment should be initiated parenterally with a combination of a third generation cephalosporin or an aminoglycoside with ampicillin. After the age of 3-6 months group 3 oral cephalosporins can be used in uncomplicated pyelonephritis. With the first febrile UTI early sonography is recommended to provide information about renal parenchymal involvement and to exclude malformations of the kidneys and urinary tract. Strategies for the recognition of vesicoureteral reflux and renal damage are under discussion. Recently published guidelines by the American Academy of Pediatrics for the diagnosis and management of UTI in febrile children and infants aged 2-24 months will most likely influence the still pending German guidelines.

Febrile urinary tract infections in young children: recommendations for the diagnosis, treatment and follow-up

We report the recommendations for the diagnosis, treatment, imaging evaluation and use of antibiotic prophylaxis in children with the first febrile urinary tract infection, aged 2 months to 3 years. They were prepared by a working group of the Italian Society of Pediatric Nephrology after careful review of the available literature and a consensus decision, when clear evidence was not available.

CONCLUSION

These recommendations are endorsed by the Italian Society of Pediatric Nephrology. They can also be a tool of comparison with other existing guidelines in issues in which much controversy still exists.

The accuracy and health risks of a voiding cystourethrogram after a febrile urinary tract infection

OBJECTIVE

Physicians often defer obtaining a voiding cystourethrogram (VCUG) after the diagnosis of urinary tract infection (UTI) due to concerns regarding increased health risks and inflated rates of vesicoureteral reflux (VUR). This study examines the health risks and accuracy of VCUG testing after diagnosis of a febrile UTI.

PATIENTS AND METHODS

A retrospective review was conducted of children aged 0-18 years admitted to Nationwide Children's Hospital with a febrile UTI in 1995-2000. Children were divided into two cohorts - those who had a VCUG performed within 1 week of diagnosis (early VCUG cohort) and those who had a VCUG performed more than 1 week after diagnosis (late VCUG cohort). All children were followed for an additional 5 years after hospital discharge.

RESULTS

The incidence and severity of VUR were similar in patients that underwent early and late VCUG testing. Patients who underwent early VCUG testing showed no sign of worsening illness after the test was performed. During the 5-year follow up, these patients did not have higher rates of return emergency department visits or hospital readmission compared to those who received late VCUG testing.

CONCLUSIONS

The rate of VUR detection does not increase with early VCUG testing. Early VCUG testing does not lead to increased risk of bacterial dissemination or urosepsis.

Technical report—Diagnosis and management of an initial UTI in febrile infants and young children

OBJECTIVES

The diagnosis and management of urinary tract infections (UTIs) in young children are clinically challenging. This report was developed to inform the revised, evidence-based, clinical guideline regarding the diagnosis and management of initial UTIs in febrile infants and young children, 2 to 24 months of age, from the American Academy of Pediatrics Subcommittee on Urinary Tract Infection.

METHODS

The conceptual model presented in the 1999 technical report was updated after a comprehensive review of published literature. Studies with potentially new information or with evidence that reinforced the 1999 technical report were retained. Meta-analyses on the effectiveness of antimicrobial prophylaxis to prevent recurrent UTI were performed.

RESULTS

Review of recent literature revealed new evidence in the following areas. Certain clinical findings and new urinalysis methods can help clinicians identify febrile children at very low risk of UTI. Oral antimicrobial therapy is as effective as parenteral therapy in treating UTI. Data from published, randomized controlled trials do not support antimicrobial prophylaxis to prevent febrile UTI when vesicoureteral reflux is found through voiding cystourethrography. Ultrasonography of the urinary tract after the first UTI has poor sensitivity. Early antimicrobial treatment may decrease the risk of renal damage from UTI.

CONCLUSIONS

Recent literature agrees with most of the evidence presented in the 1999 technical report, but meta-analyses of data from recent, randomized controlled trials do not support antimicrobial prophylaxis to prevent febrile UTI. This finding argues against voiding cystourethrography after the first UTI.

A guideline for the inpatient care of children with pyelonephritis

BACKGROUND AND OBJECTIVES

Febrile urinary tract infections and pyelonephritis are common in children and frequently lead to hospitalization for management, especially in the child who appears toxic. The American Academy of Pediatrics (AAP) practice parameter on the diagnosis, treatment and evaluation of the initial urinary tract infection in febrile infants and young children provides experience and evidence-based guidelines for the practitioner caring for children between the ages of 2 months to 2 years. No established guideline exists for older children and the AAP guideline does not specifically focus on inpatient care.

METHODS

We conducted a comprehensive review of recently published literature and practice guidelines to develop a consensus on the inpatient diagnosis and management of children with pyelonephritis.

RESULTS

Eight recommendations are proposed for the diagnosis and management, including revised guidelines for the imaging studies postpyelonephritis on the basis of current best evidence.

CONCLUSION

Proper diagnosis of pyelonephritis, timely initiation of appropriate therapy and identification of children at risk for renal injury will help to reduce immediate as well as long-term complications due to chronic kidney disease.

Timing of voiding cystourethrography in infants with first time urinary infection

The aim of the study was to evaluate whether the timing of performing a voiding cystourethrography (VCUG) following a first urinary tract infection (UTI) in infants is related to the presence or the severity of vesicoureteral reflux (VUR). A total of 411 children (male 230, female 181) with a first-recognised UTI between ages 15 days and 12 months (median 3 months) underwent a VCUG within 4-81 days (median 9 days) following diagnosis. The presence and the grade of the VUR were compared in two groups: an "early" group in which the VCUG was performed during the first week of the start of treatment and a "late" group in which the examination was performed during the second week or thereafter. The prevalence of VUR in the study cohort was 23.3% (96/411 infants). A VUR was diagnosed in 44 infants in the early group (28%) and in 52 in the late group (21%). Reflux of grade III or higher was seen in 25/44 (57%) of the infants in the early group and in 27/52 (52%) infants in the late group. These differences were not significant. Our results suggest that neither the presence nor the grade of VUR in infants is influenced by the timing of the examination following diagnosis. We therefore recommend that it is better to perform VCUG as soon as possible, provided the inflammation has subsided.

Urinary tract infection in the newborn: clinical and radio imaging studies

The objective of this study was to assess clinical characteristics and results of radio imaging studies and compare community-acquired urinary tract infection (UTI) with nosocomial UTI in 301 neonates with UTI consecutively admitted to 28 neonatal units in Spain over 3 years (community-acquired UTI, n = 250; nosocomial UTI, n = 51). UTI was diagnosed in the presence of symptoms of infection together with any colony growth for a single pathogen from urine obtained by suprapubic aspiration, or >or=10(4) CFU/ml for a single pathogen from urine obtained by urethral catheterization. Abnormal renal ultrasound was present in 37.1% of cases (34% in community-acquired UTI and 54.5% in nosocomial UTI, P < 0.01). The voiding cystourethrography (VCUG) showed vesicoureteral reflux (VUR) in 27% of cases (23.8% in community-acquired UTI and 48.6% in nosocomial UTI, P < 0.01). In patients with abnormal renal ultrasound and VUR, renal scan with dimercaptosuccinic acid (DMSA) performed early after UTI revealed cortical defects in 69.5% of cases. However, in patients with abnormal renal ultrasound and normal VCUG, DMSA also revealed cortical defects in 39% of cases. The absence of VUR in neonates with UTI and abnormal renal ultrasound does not exclude the presence of cortical defects suggestive of pyelonephritis.

Does early treatment of urinary tract infection prevent renal damage?

OBJECTIVE

Therapeutic delay has been suggested as the most important factor that is likely to have an effect on the development of scarring after acute pyelonephritis. However, this opinion has not been supported by prospective studies, so we tested it.

METHODS

In a prospective clinical study, we evaluated whether the time interval between the onset of the renal infection and the start of therapy correlates with the development of acute inflammatory changes and the subsequent development of renal scars, documented by dimercaptosuccinic acid scintigraphy. A total of 278 infants (153 male and 125 female) aged 0.5 to 12.0 months with their first urinary tract infection were enrolled in the study.

RESULTS

The median time between the onset of infection and the institution of therapy was 2 days (range: 1-8 days). Renal inflammatory changes were documented in 57% of the infants. Renal defects were recorded in 41% of the patients treated within the first 24 hours since the onset of fever versus 75% of those treated on day 4 and onward. Renal scarring was developed in 51% of the infants with an abnormal scan in the acute phase of infection. The frequency of scarring in infants treated early and in those whose treatment was delayed did not differ, suggesting that once acute pyelonephritis has occurred, ultimate renal scarring is independent of the timing of therapy. Acute inflammatory changes and subsequent scarring were more frequent in the presence of vesicoureteral reflux, especially that which is high grade. However, the difference was not significant, which suggests that renal damage may be independent of the presence of reflux.

CONCLUSIONS

Early and appropriate treatment of urinary tract infection, especially during the first 24 hours after the onset of symptoms, diminishes the likelihood of renal involvement during the acute phase of the infection but does not prevent scar formation.

Diagnosis and management of pediatric urinary tract infections

Urinary tract infection (UTI) is among the most commonly diagnosed bacterial infections of childhood. Although frequently encountered and well researched, diagnosis and management of UTI continue to be a controversial issue with many challenges for the clinician. Prevalence studies have shown that UTI may often be missed on history and physical examination, and the decision to screen for UTI must balance the risk for missed infections with the cost and inconvenience of testing. Interpretation of rapid diagnostic tests and culture is complicated by issues of contamination, false test results, and asymptomatic colonization of the urinary tract with nonpathogenic bacteria. The appropriate treatment of UTI has been controversial and has become more complex with the emergence of resistance to commonly used antibiotics. Finally, the anatomic evaluation and long-term management of a child after a UTI have been based on limited evidence, and newer studies question some of the tenets of prior recommendations. The goal of this review is to provide an up-to-date summary of the literature with particular attention to practical questions about diagnosis and management for the clinician.

The role of indirect radionuclide cystography during the acute phase of pyelonephritis in young women

OBJECTIVE

To review our experience using dynamic 99mTc-diethylenetriamine penta-acetic acid renal scintigraphy combined with indirect radionuclide cystography (IRC) in the acute phase of pyelonephritis, as a possible alternative to the conventional imaging, as investigating acute pyelonephritis usually includes imaging the upper urinary tract during the acute phase, to exclude obstruction, and delayed voiding cysto-urethrography (VCUG) when underlying vesico-ureteric reflux (VUR) is suspected.

PATIENTS AND METHODS

Between 1997 and 1999, 47 young women (median age 22 years, range 18-37) were hospitalized for acute pyelonephritis. The combined study was used during the acute phase of the disease, usually within 24 h of hospitalization. The principle of IRC is based on the reappearance of radioactivity in the ureters or kidneys after previously detecting renal clearance of an intravenously injected radioisotope. The increase in radioactivity over the ureters or kidneys indicates VUR. The subsequent follow-up included VCUG, after recovery and at least 6 weeks after discharge.

RESULTS

Overall, 47 patients had early IRC studies; obstruction of the urinary tract during the acute phase of the disease was excluded in all. In 13 (28%) of the patients early IRC studies showed VUR involving 21 upper tract units. The renal parenchymal scan was impaired in 17 (36%) patients, and six of these 17 also had detectable concomitant reflux on IRC. Overall, 24 IRC studies (51%) were considered positive, showing VUR, renal parenchymal pathology or both; 23 (49%) were normal. Follow-up VCUG was used in 32 patients (68%); only three (9%) detected VUR. All of the patients with VUR on follow-up VCUG had also had an abnormal early IRC study, showing either reflux (two) or findings suggestive of pathological renal parenchyma (one).

CONCLUSIONS

In addition to the well-established role of renal scintigraphy in excluding obstruction of the collecting system, early IRC is characterized by high sensitivity and accurate negative predictive value for detecting VUR. It can therefore be used to screen adults presenting with acute pyelonephritis for the presence of VUR. Patients with an abnormal IRC require follow-up VCUG after complete recovery, while those with a negative study may be managed expectantly, with no further radiological evaluation. This proposed strategy may avoid up to half of the delayed VCUG studies, preclude the related inconvenience, and substantially reduce the costs.

Timing of voiding cystourethrogram in the investigation of urinary tract infections in children

OBJECTIVE

To determine whether the detection of vesicoureteral reflux (VUR) in children with a urinary tract infection (UTI) is more likely if the voiding cystourethrogram (VCUG) is performed early (within the first 7 days after diagnosis) or late (>7 days after diagnosis).

STUDY DESIGN

We conducted a retrospective case review of children <5 years of age admitted with a first episode of UTI to a tertiary care pediatric hospital over a 2-year period. Timing of the VCUG was at the discretion of the attending pediatrician. Differences in age, sex, mean time to performing the VCUG, and incidence of VUR between the 2 groups (VCUG performed early vs late) were compared by using Student t test (for age) and chi(2) test (for sex and incidence of VUR). Potential confounders (age and sex) were included in a multiple logistic regression analysis.

RESULTS

A total of 162 patients were eligible for inclusion. Mean age was 181 days, and 43.8% were female. The incidence of VUR was 21.6%. The early group consisted of 82 patients, and the late group consisted of 80. No significant difference was found for age or sex or for the incidence of reflux (17.1% vs 26.3%, P =.219), with a crude odds ratio of.59 (95% CI 0.3-1.2, P >.05).

CONCLUSION

The rate of detection of VUR in children with a first episode of UTI does not increase when the VCUG is done early (within the first 7 days of diagnosis) rather than later.

Urinary tract infection: new perspectives on a common disease

Urinary tract infection is an important cause of morbidity in children, and affects up to 10% of the childhood population. Recent information suggests that the long-term outcome for children with urinary tract infection is much better than previously believed, with causal links to end-stage renal disease and hypertension not demonstrated despite 20-year cohort studies. Improvements in the use of dipstick and clinical features as diagnostic tools have occurred, but culture is still needed if the diagnosis of urinary tract infection is to be definitively established. Interventions to prevent recurrent urinary tract infection, particularly low-dose, long-term antimicrobial agents may not be effective and placebo-controlled trials are now required.

Urinary tract infection in childhood

Over the past year, research about urinary tract infections in childhood has yielded new data about methods to detect, treat, and evaluate children who develop urinary tract infection. New imaging modalities have been studied. Long term studies following children with urinary tract infection have also been published over the last year. However, major questions remain to be answered, including the underlying basis of host-pathogen interactions in the urinary tract, as well as the most effective methods for clinical diagnosis and management.

Vesicoureteral reflux and urinary tract infections

Urinary tract infection is a common problem in children. The combination of vesico-ureteric reflux (VUR) and urinary tract infection may predispose children to pyelonephritis and subsequent complications. This review outlines the modifications suggested in the recent literature in the protocol for investigations and diagnosing VUR. Recent interest has been expressed in studying certain molecular markers to measure non-invasively renal damage in children with VUR. Long term results of comparative trials between medical and surgical management have been published recently.