Imaging studies after a first febrile urinary tract infection in young children

Kidney length and scarring in children with urinary tract infection: importance of ultrasound scans

BACKGROUND

Many studies have demonstrated that dimercaptosuccinic acid (DMSA) scintigraphy is the most sensitive diagnostic method in the identification of irreversible renal lesions (scars) in children with previous episodes of acute pyelonephritis (APN). This study assessed the reliability of ultrasound in identifying reflux nephropathy in children with acute pyelonephritis with or without vesicoureteric reflux (VUR).

METHODS

Eighty children (45 female and 35 male, age range 5 months to 10 years, average age 2 years 1 month) with a positive history for at least one episode of APN participated in this study. All children underwent voiding cystourethrography, DMSA scintigraphy 4 to 8 months after the most recent episode of APN, and an ultrasound test evaluation less than 2 months after DMSA scintigraphy.

RESULTS

Voiding cystourethrograms showed VUR in 52 children (68%); 13 of these were bilateral, for a total of 65 refluxing kidney units of the 154 (42%) evaluated; DMSA scintigram was normal for 108 of 154 kidneys (70%). Of the 65 kidneys with VUR, DMSA scintigram displayed normal findings in 29 cases (45%) and pathologic findings in 36 (55%). In the 79 nonrefluxing kidneys, DMSA scintigram was normal in 69 cases (87%). The relative risk of scarring in VUR kidneys is 2.6. The ultrasound study recorded a maximum longitudinal diameter between the 5th and 95th percentiles in 80 of 89 (81%) kidneys without VUR and in 21 of 65 (32%) with VUR. A significant correlation was found between maximum longitudinal diameters and DMSA scintigraphic findings in kidneys with VUR and those without VUR, respectively.

CONCLUSION

This study establishes that ultrasound scans, by means of a simple and reproducible measurement technique, maximum longitudinal diameter, have a predictive value with regard to the presence of scars, with few exceptions. This finding, in our opinion, could lead to a decrease in the number of invasive procedures, in particular DMSA scan, in patients with APN.

The presence of vesicoureteric reflux does not identify a population at risk for renal scarring following a first urinary tract infection

BACKGROUND

Childhood urinary tract infection (UTI) with or without vesicoureteric reflux (VUR) may predispose to renal scarring. There is no clear consensus in the literature regarding imaging following UTI in infancy.

AIMS

To define the role of cystography following a first UTI in children aged under 1 year, when urinary tract ultrasonography (US) is normal.

METHODS

Retrospective data collection of 108 children (216 renal units) aged under 1 year at the time of a bacteriologically proven UTI. All had a normal US and underwent both catheter cystogram and DMSA test. Sensitivity, specificity, likelihood ratios positive and negative, and diagnostic odds ratio were calculated for VUR on cystography versus scarring on DMSA.

RESULTS

VUR was shown in 25 (11.6%) renal units. Scarring on DMSA was seen in 8 (3.7 %) kidneys. Only 16% of kidneys with VUR had associated scarring; 50% of scarred kidneys were not associated with VUR. The likelihood ratio positive was 4.95 (95% CI 2.22 to 11.05) and the likelihood ratio negative was 0.56 (95% CI 0.28 to 1.11). The diagnostic odds ratio was 8.9, suggesting that cystography provided little additional information.

CONCLUSION

Since only 16% of children with VUR had an abnormal kidney, the presence of VUR does not identify a susceptible population with an abnormal kidney on DMSA. In the context of a normal ultrasound examination, cystography contributes little to the management of children under the age of 1 year with a UTI. In this context, a normal DMSA study reinforces the redundancy of cystography.

Procalcitonin as a predictor of vesicoureteral reflux in children with a first febrile urinary tract infection

OBJECTIVE

A first febrile urinary tract infection leads to the diagnosis of vesicoureteral reflux in 20% to 40% of children. Systematic voiding cystourethrography then is recommended. However, for 60% to 80% of the children, voiding cystourethrography is a posteriori normal. Moreover, it is irradiating, painful, and expensive. Thus, selective approaches are needed. Because procalcitonin has been shown to be associated with severe pyelonephritis and renal scars, which are correlated to vesicoureteral reflux, we analyzed its relationship with vesicoureteral reflux.

METHODS

A retrospective hospital-based cohort study included all children who were 1 month to 4 years of age and had a first febrile urinary tract infection. Univariate and multivariate analyses were performed.

RESULTS

Among 136 patients included, 25% had vesicoureteral reflux. The median procalcitonin concentration was significantly higher in children with reflux than in those without (1.2 vs 0.6 ng/mL). High procalcitonin (> or =0.5 ng/mL) was associated with reflux (odds ratio [OR]: 4.6; 95% confidence interval [CI]: 1.6-16.2). After logistic-regression adjustment for all potential confounders, the association remained significant (OR: 4.9; 95% CI: 1.7-14.0). The relationship was stronger for high-grade (> or =3) reflux (OR: 8.7; 95% CI: 1.2-382) than low-grade reflux (OR: 3.6; 95% CI: 1.1-15.3). High procalcitonin sensitivities were 85% (95% CI: 70-94) and 92% (95% CI: 65-99) for all-grade and high-grade reflux, respectively, with 44% specificity (95% CI: 35-54).

CONCLUSION

High procalcitonin is a strong and independent predictor of vesicoureteral reflux and could be used to identify low-risk patients to avoid unnecessary voiding cystourethrography.

Compliance with guidelines for the medical care of first urinary tract infections in infants: a population-based study

BACKGROUND

No population-based studies have examined the degree to which practice parameters are followed for urinary tract infections in infants.

OBJECTIVE

To describe the medical care of children in their first year of life after a first urinary tract infection.

METHODS

Using Washington State Medicaid data, we conducted a retrospective cohort study of children with a urinary tract infection during their first year of life to determine how many of these children received recommended care based on the most recent guidelines from the American Academy of Pediatrics. Recommended care included timely anatomic imaging, timely imaging for reflux, and adequate antimicrobial prophylaxis. Multivariate logistic-regression models were used to evaluate if hospitalization for first urinary tract infection, young age at time of diagnosis, gender, race, primary language of parents, having a managed care plan, and rural location of household residence were associated with recommended care.

RESULTS

Less than half of all children diagnosed with a urinary tract infection in their first year of life received the recommended medical care. Children who were hospitalized for their first urinary tract infection were significantly more likely than children who were not hospitalized to receive anatomic imaging (relative risk [RR]: 1.38; 95% confidence interval [CI]: 1.20-1.57) and imaging for reflux (RR: 1.62; 95% CI: 1.34-1.90).

CONCLUSIONS

There is poor compliance with guideline-recommended care for first urinary tract infections in infants in a Medicaid population. Given the trend toward increased outpatient management of urinary tract infections, increased attention to outpatient imaging may be warranted.

Low bacterial count urinary tract infections in infants and young children

The purpose of the study was to compare bacterial species, clinical, laboratory and imaging findings ((99m )Tc-dimercaptosuccinic acid renal scan and voiding cystogram) in infants and children with high (>/=10(5) colony forming units (CFU)/ml, group A patients) and low (</=5 x 10(4) CFU/ml, group C patients) bacterial count in urine cultures during first episode of urinary tract infection. Group B included patients with intermediate CFU/ml. Included were 419 symptomatic patients with: (a) no previous antibiotic treatment, (b) urine samples for quantitative cultures taken by bladder catheterisation or suprapubic bladder aspiration, (c) growth of only one microorganism, and (d) age </=54 months (age of the oldest patient of group C). Out of 419 cultures, Escherichia coli grew in 315 (75.2%), gram-negative bacteria except E. coli in 91 (21.7%) and gram-positive in 13 (3.1%). Group C patients were significantly ( P <0.0001) more often affected with gram-negative pathogens except E. coli than group A patients (21/44 versus 67/360). Most of group C patients were younger than 24 months of age; none was older than 54 months. Comparison of the prevalence of clinical and laboratory (leucocyte count, CRP, ESR) findings between groups A and C showed no significant differences. There was no statistically significant difference in the prevalence of pyelonephritis, reflux and urological malformations (except reflux) between groups A and C.

CONCLUSION

Low bacterial count urinary tract infections mainly affect infants and young children and are often due to gram-negative bacteria other than E. coli. Clinical and laboratory findings, prevalence of pyelonephritis, reflux and urological malformations are similar in high and low bacterial count urinary tract infections.

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.

[Primary vesicoureteral reflux treatment in childhood: comparsion of two systematic review]

Many medical practices are being carried out unawares of their efficiency, or of their actual impact on the health of the patients, therefore it is necessary to consider the support of professional recommendations with scientific evidence.

THE PRIMARY OBJECTIVE

To perform a systematic review (SR) of the therapeutic management of primary VUR in pediatric urology.

MATERIAL AND METHODS

A systematic review has been performed, including scientific evidence-based medicine criteria, of the articles published in all of the available databases. Inclusion criteria concerning basic quality of the articles were considered essential, as well as exclusion criteria to be able to reject the articles.

RESULTS AND DISCUSSION

Subsequently, and following the critic reading of greater than 320 articles, statistical study of the grouped data was performed according to the type of treatment and to the benefits contributed by each treatment, and also to their undesirable effects. Finally we have made a comparison between our results and recent Cochrane Systematic Review. The following Conclusions were drawn from the results obtained and from the analysis of the texts. Both medical and surgical treatment present with similar effectiveness concerning resolution of grades I, II and III of VUR, and the former one is the recommended initial treatment following diagnosis. Endoscopic treatment is exactly as effective as open surgery for grades I, II and III with fewer undesirable effects secondary. There are no differences concerning the efficacy of the different injected substances. Not enough evidences exist for degrees IV and V that may recommend or advise against any of the treatments. In any degree of VUR, open surgical treatment is superior as far as medical treatment is concerned only regarding the number of acute pyelonephritis episodes during followup. This conclusion cannot be applied on endoscopic treatment.

The sensitivity of antenatal ultrasound for predicting renal tract surgery in early childhood

OBJECTIVE

To establish the sensitivity of antenatal ultrasound for identifying the need for renal tract surgery in infancy and early childhood.

METHODS

A retrospective analysis of the surgical records in children under 5 years of age undergoing renal tract surgery in a regional pediatric urological surgery referral unit was carried out. All records between May 1997 and July 2002 were examined to assess the relationship between prenatal ultrasound findings and postnatal surgical pathology.

RESULTS

A total of 106 operations had been performed. The detection rate of multicystic renal dysplasia was 100% (17/17). The equivalent detection rates for pelviureteral junction obstruction, duplex renal system and vesicoureteral reflux were 82.8, 67 and 26.1%, respectively. None of the babies with renal tumors had abnormal antenatal ultrasound findings. The diagnosis of postnatal renal surgical pathology was made on the basis of prenatal scan findings in 59.6% of cases, while recurrent urinary tract infection led to the diagnosis in 26.0%.

CONCLUSIONS

Approximately 40% of children requiring surgery for renal tract pathology will have a normal antenatal ultrasound examination. The prevalence of abnormal antenatal ultrasound findings varies depending on the type of renal tract pathology. Despite these findings, the commonest indicator for surgery remains abnormal prenatal scan findings, followed by recurrent urinary tract infections.

Ominous findings in toddlers with increasing abdominal girth: two unusual cases and a review of the clinical evaluation

A preverbal toddler who presents with a distended abdomen can pose a difficult clinical problem. The differential diagnosis is extremely broad and consists of etiologies ranging from the benign to the life threatening. In this case report, we present 2 unusual life-threatening cases of abdominal distention in well-appearing toddlers and a review of the clinical evaluation for the emergency practitioner.

Post-pyelonephritic renal scars are not associated with vesicoureteral reflux in children

PURPOSE

Children with pyelonephritis are at risk for renal damage. We assess the value of clinical signs and urological abnormalities in predicting renal scars in children following pyelonephritis.

MATERIALS AND METHODS

A total of 64 hospitalized children (29 females and 35 males, median age 2.9 years) underwent ultrasonography and technetium labeled dimercapto-succinic acid (DMSA) scintigraphy imaging within 1 week following the diagnosis of the first pyelonephritis. Voiding cystourethrography was performed 8 weeks after the diagnosis. Followup DMSA scintigraphy was performed in 58 patients after 2 years of followup.

RESULTS

Urological abnormalities observed were vesicoureteral reflux (VUR, grade 2 or higher) in 11 patients (19%), nonrefluxing and nonobstructed megaureter in 2 (4%) and pyeloureteral obstruction in 1 (2%). The first DMSA scintigraphy showed parenchymal defects in 48% of patients. VUR did not increase the risk of renal defects. At 2 years after the infection 12 of the 58 patients (21%) had renal scars. Nine of these patients did not have VUR. However, 2 patients with high grade VUR and repeat infections demonstrated deterioration of kidney function during followup. The patients with renal scars were older than those without scars (3.1 vs 0.8 years, p = 0.0291) at the time of infection.

CONCLUSIONS

Renal scars after first pyelonephritis are in most cases not associated with abnormalities of the urinary tract, but are caused by the infection itself. However, structural abnormalities may predispose to recurrent infections. Following pyelonephritis new renal scars may develop in all age groups in both sexes.

Urologic diseases in North America Project: trends in resource utilization for urinary tract infections in children

PURPOSE

We evaluated the health utilization and economic burden on society of urinary tract infections (UTIs) in children using a variety of public and commercial health care databases.

MATERIALS AND METHODS

Numerous available databases were evaluated for health care utilization, including inpatient hospitalization, and outpatient physician and emergency department visits, by children with a coded diagnosis of urinary tract infection. Utilization was analyzed by age, gender, race, insurance type and geographic location, and trends were assessed during the last decade.

RESULTS

UTIs resulted in more than 1.1 million physician visits annually, accounting for 0.7% of doctor visits and occurring in 2.4% to 2.8% of children. Overall, inpatient hospitalization decreased slightly, although pyelonephritis still accounted for more than 13,000 admissions. Infants were more likely to receive inpatient care for UTIs than children or adolescents, although hospital costs were higher in adolescents. Inpatient hospital costs are estimated to be greater than 180 million dollars per year.

CONCLUSIONS

Pediatric UTIs constitute a significant health burden on society. Available data do not allow a full accounting of costs due to a lack of information regarding outpatient expenses, as well as the cost of ancillary evaluation and treatment. However, the magnitude of the burden suggests the importance of further research and data collection of health care utilization in the pediatric population.

Imaging strategies in pediatric urinary tract infection

This article is focused on the controversial topic of imaging strategies in pediatric urinary tract infection. A review of the recent literature illustrates the complementary roles of ultrasound, diagnostic radiology and nuclear medicine. The authors stress the key role of ultrasound which has recently been debated. The commonly associated vesicoureteric reflux has to be classified as congenital or secondary due to voiding dysfunction. A series of frequently asked questions are addressed in a second section. The proposed answers are not the product of a consensus but should rather be considered as proposals to enrich the ongoing debate concerning the evaluation of urinary tract infection in children.

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.

Can MRI replace DMSA in the detection of renal parenchymal defects in children with urinary tract infections?

BACKGROUND

Renal parenchymal defects may be a consequence of urinary tract infections (UTI) in childhood. MRI is a non-radiation imaging modality compared with DMSA scanning.

OBJECTIVE

To compare DMSA with MRI for the detection of renal parenchymal defects in children presenting for radiological investigation after a first UTI.

MATERIALS AND METHODS

Both DMSA and MRI were performed at the same appointment in 37 children (aged 4 months-13 years; mean 4.5 years) with a history of UTI. Both planar and SPECT DMSA were performed. MRI of the kidneys employed axial and coronal T1-, T2- and fat-saturated T1-weighted (T1-W) sequences. Some children had imaging after IV contrast medium.

RESULTS

The coronal fat-saturated T1-W sequence was the best sequence and it detected all the findings on MRI. MRI had a sensitivity of 77% and a specificity of 87% for the detection of a scarred kidney using DMSA as the gold standard. MRI diagnosed pyelonephritis in two children that had been interpreted as scarring on DMSA.

CONCLUSIONS

Renal MRI using a single, coronal, fat-saturated T1-W sequence is a rapid, accurate and minimally invasive technique for the detection of renal scarring that does not employ ionizing radiation.

FEBRILE URINARY TRACT INFECTIONS IN INFANTS: RENAL ULTRASOUND REMAINS NECESSARY

PURPOSE

Current guidelines from the American Academy of Pediatrics recommend voiding cystourethrography (VCUG) and renal ultrasound for the radiographic evaluation of infants after a febrile urinary tract infection. Some recent studies have suggested that ultrasound is not necessary in the era of prenatal ultrasound. We reviewed our experience to ascertain the influence that ultrasound has on the treatment of these infants.

MATERIALS AND METHODS

We reviewed retrospectively the charts of 282 consecutive patients (5 days to 6 months old, 98 males and 184 females) who underwent radiographic evaluation for a febrile urinary tract infection between October 1995 and August 2001. All patients were evaluated at our institution with VCUG and renal ultrasound.

RESULTS

Of 203 patients with normal VCUG ultrasound was abnormal in 32 (16%). Subsequent evaluation demonstrated 1 case each of significant ureteropelvic junction obstruction, ectopic ureter in a bilaterally duplicated system, renal duplication, renal duplication with calculus, ectopic ureter, renal cysts, multicystic dysplastic kidney and renal scarring. In addition, there were 3 cases of ureterovesical obstruction. No significant renal pathology was identified in the other cases. Two of these patients underwent operative intervention. Treatment or parental counseling was altered in 7 others, for a total of 9 of the 203 patients (4.4%).

CONCLUSIONS

In our population renal ultrasound adds information to the radiographic evaluation of infants after a febrile urinary tract infection. This information alters treatment and parental counseling in a significant number of patients.

Antibiotics or surgery for vesicoureteric reflux in children

CONTEXT

1-2% of children have vesicoureteric reflux (VUR). VUR occurs in 25-40% of children with acute pyelonephritis. VUR can lead to renal scarring, hypertension, and end-stage renal disease. The best form of treatment for children with VUR is debated: no treatment, long-term antibiotic prophylaxis, surgery, or a combination of antibiotic prophylaxis and surgery. In children with recurrent urinary tract infections (UTIs) and progressive renal damage, despite antibiotic prophylaxis, surgical correction of VUR, especially high-grade VUR, is generally recommended.

STARTING POINT

Danielle Wheeler and colleagues recently did a meta-analysis of ten randomised controlled trials (964 children) to evaluate whether any intervention for VUR is better than no treatment (Cochrane Database Syst Rev 2004; 3: CD001532). The main endpoints were incidence of UTIs, new or progressive renal damage, renal growth, hypertension, and glomerular filtration rate. They concluded that it is uncertain whether the identification of children with VUR is associated with clinically important benefit. The additional benefit of surgery over antibiotics is small. WHERE NEXT? New strategies for management will require a tailored diagnostic and therapeutic approach, including non-invasive or less invasive diagnostic procedures, and a less aggressive therapeutic approach. Whether the common practice of cystourethrography as a first-line investigation is warranted needs evaluation. The goal of paediatricians in the future, to prevent kidney damage, will probably be prevention of renal parenchymal injury and not necessarily the correction of ureterovesical junction anomalies. Because two main clinical pictures of VUR (diagnosed prenatally or postnatally with different age and sex distribution) can be identified, boys and girls will probably be managed differently. The factors responsible for congenital and acquired renal injury in children with VUR need to be studied.

Pathogenesis of urinary tract infections with normal female anatomy

Recurrent urinary tract infections (UTIs) are common among girls and young women who are healthy and have anatomically normal urinary tracts. These infections are a main source of morbidity and health-care costs in this population. The interaction between specific infecting bacteria and urinary tract epithelium characteristics underlies the pathogenesis of this disease. Several pathogen-related factors predispose people to recurrent UTI, including periurethral bacterial colonisation and Escherichia coli virulence. Host behavioural risk factors include voiding dysfunction, high intercourse frequency, and oral contraceptive and spermicide use. The role of vesicoureteral reflux in recurrent childhood UTI is probably overestimated in the medical literature and is important only in a small group of children with high-grade reflux. Family pedigree analysis suggests a familial genetic predisposition for UTI among young females. Animal models show the multigenic nature of recurrent UTI. Putative candidate genes for the disease include ABH blood groups, interleukin-8 receptor (CXCR1), the human leucocyte antigen locus, toll-like receptors, tumour necrosis factor, and Tamm-Horsfall protein.

Vesicoureteral reflux: who benefits from surgery?

Increased recognition of the association between urinary tract infections and reflux, sibling screening, and the evaluation of antenatal hydronephrosis have resulted in an increase in the diagnosis of reflux early in life. Although many children would sustain no untoward affects of their condition if reflux were left untreated, the disease can be severe and even life threatening. Although antireflux operations have been refined and improved, it remains difficult to determine which individuals truly benefit from these operations. A large prospective randomized placebo-antibiotic-operation study with long-term follow-up is needed, as is the development of nomograms, to assess the individual child's risk of adverse outcomes.

Urinary tract infection in children: etiology and epidemiology

The urinary tract is a relatively common site of infection in infants and young children. Urinary tract infection (UTI) may result in significant acute morbidity, as well as longterm medical complications. Recent advances elucidating the pathogen-host interaction have broadened the understanding of the pathogenesis and clinical progression of pediatric UTI. This article focuses on the epidemiology and pathogenesis of pediatric UTI, and briefly discusses UTI-related complications.

Children with a febrile urinary tract infection and a negative radiologic workup: factors predictive of recurrence

OBJECTIVES

To determine the recurrence rate and risk factors for urinary tract infection (UTI) in children who present with a febrile UTI and have a negative radiologic evaluation. Febrile UTIs with no urinary tract abnormalities are a common cause of morbidity in children.

METHODS

We performed a retrospective review of all children referred to our medical center after a febrile UTI.

RESULTS

We reviewed 850 charts. Of 850 children, 78 had had a febrile UTI and normal ultrasound and voiding cystourography findings. Of the 78 children, 25 had had a recurrent UTI (3 boys and 22 girls). Forty-five percent of the girls with a febrile UTI developed a recurrent UTI and 14% of the boys had a recurrent UTI (P = 0.02). Three boys (two younger than 1 year of age) were uncircumcised and had one recurrent febrile UTI. Eleven (39%) of 28 girls who first presented at younger than 1 year of age and 7 (58%) of 12 girls who presented at 5 years of age or older had recurrent UTIs. The recurrence rate in the 2 to 5-year-old age group was 24% (4 of 17). Seven of the older girls exhibited symptoms of dysfunctional elimination syndrome.

CONCLUSIONS

In children with a febrile UTI and a negative radiologic evaluation, recurrence was more common in girls. Boys who were uncircumcised may be at an increased risk of infection during the first year of life. In girls, the age at the time of the first infection was not predictive of recurrence. Although dysfunctional voiding and elimination may contribute to recurrent febrile UTIs in young children, an association seems to be present in children 5 years old and older.

Urinary tract infection: is there a need for routine renal ultrasonography?

AIMS

To assess the yield of routine renal ultrasound (RUS) in the management of young children hospitalised with first uncomplicated febrile urinary tract infection (UTI).

METHODS

All children aged 0-5 years who had been hospitalised over a two year period with first uncomplicated febrile UTI in a medium size institutional regional medical centre were included. Children with known urinary abnormalities and/or who had been treated with antibacterial agents within seven days before admission were excluded. All included children underwent renal ultrasonography during hospitalisation and voiding cystouretrography (VCUG) within 2-6 months. The yield of RUS was measured by its ability to detect renal abnormalities, its sensitivity, specificity, and positive and negative predictive values for detecting vesicoureteral reflux (VUR), and by its impact on UTI management.

RESULTS

Of 255 children that were included in the study, 33 children had mild to moderate renal pelvis dilatation on RUS suggesting VUR, of whom only nine had VUR on VCUG. On the other hand, in 36 children with VUR on VCUG the RUS was normal. The sensitivity, specificity, positive predictive value, and negative predictive value of abnormal RUS for detecting VUR were 17.7%, 87.6%, 23.5%, and 83.2% respectively. In none of the patients with abnormal RUS was a change in the management at or following hospitalisation needed.

CONCLUSION

Results show that the yield of RUS to the management of children with first uncomplicated UTI is questionable.

DMSA study performed during febrile urinary tract infection: a predictor of patient outcome?

Technetium-99m dimercaptosuccinic acid (DMSA) study has been advocated as a method for the assessment of renal sequelae after acute febrile urinary tract infection (UTI). However, it is not known whether DMSA scintigraphy performed during acute UTI has any prognostic value for outcome assessment. The objective of this study was to evaluate the usefulness of DMSA scintigraphy performed during UTI as a predictor of patient outcome, to identify children at risk of events [vesico-ureteral reflux (VUR) or recurrent UTI] that may lead to the development of progressive renal damage. One hundred and fifty-two children (including 78 girls) with a mean age of 20 months (range 1 month to 12 years) with first febrile UTI were evaluated by DMSA scintigraphy during acute UTI. After acute UTI, children were explored by voiding cysto-urethrography. Children who presented an abnormal DMSA study, or a normal DMSA study but VUR or recurrent UTI, underwent a DMSA control study 6 months after UTI. Children with VUR were followed up by direct radionuclide cystography. DMSA scintigraphy performed during acute UTI was normal in 112 children (74%). In 95 of these children, follow-up DMSA scintigraphy was not performed owing to a good clinical outcome. In the remaining 17 children, follow-up scintigraphy was normal. Forty children (26%) presented abnormal DMSA study during acute UTI. Twenty-five of them presented a normal follow-up DMSA, and 15 presented cortical lesions. Children with abnormal DMSA had a higher frequency of VUR than children with normal DMSA (48% vs 12%). It is concluded that children with normal DMSA during acute UTI have a low risk of renal damage. Children with normal follow-up DMSA and low-grade VUR have more frequent spontaneous resolution of VUR.

Urinary tract infections in infants and children: a comprehensive overview

PURPOSE OF REVIEW

Urinary tract infections are the most common serious bacterial infections in infants and young children. This review focuses on new additions to the literature for the period August 22, 2002, to August 21, 2003.

RECENT FINDINGS

There is still considerable interest in determining which test is best to predict the likelihood of a positive urine culture in children at risk for urinary tract infection. One new analysis and several older analyses suggest that the finding of pyuria, as measured by at least 10 leukocytes/mm3 on unspun urine is a very valuable cutoff for identifying infants for whom urine culture is warranted. Several new investigations have studied the value of various imaging studies in children with urinary tract infections. It has been shown that the finding of vesicoureteral reflux is variable and that single studies may underestimate or overestimate the degree of reflux. The natural history for lower grades of reflux (grades 1, 2, and 3) is spontaneous resolution at a rate of 13% per year. The rationale for the determination of the degree of reflux by voiding cystourethrogram is to guide the institution of antimicrobial prophylaxis or surgical intervention until the reflux resolves. This is based on the assumption, as yet unproven, that these interventions will prevent or decrease reinfection and thereby prevent the development of renal scarring. Data are presented indicating that there is still no evidence that this assumption is correct.

SUMMARY

Continued attention to the need for and benefit of imaging procedures in children with urinary tract infection mandates that there be a randomized, controlled prospective trial of antimicrobial prophylaxis versus no treatment for children with various degrees of reflux.

Cytokines and Cell Adhesion Molecules in the Inflammatory Response during Acute Pyelonephritis

Urinary tract infection is a common bacterial infection of childhood. Renal parenchymal scarring, a recognised complication of urinary tract infection, is responsible for up to 24% of children entering end-stage renal failure. Why acute inflammation results in renal scarring in some children whilst in others complete resolution occurs without scarring is at present poorly understood. This article reviews the role of the cytokines, adhesion molecules and growth factors in the inflammatory response during acute pyelonephritis and renal parenchymal scarring. We hypothesize that inter-individual variability in cellular response may in part be responsible for this variable clinical outcome.

Pediatric urinary tract infections: the role of fluoroquinolones

Infections of the urinary tract (UTI) occur commonly in the pediatric population. Because of the high association of pediatric UTI with congenital structural anomalies of the urinary tract and with dysfunctional elimination syndromes, it is far more common for children to be categorized as having complicated UTI than their adult counterparts. And for children more intensive therapy is often required. Early and effective treatment of UTIs in the pediatric patient is considered essential to prevent long term morbidity and potential mortality from end stage renal disease. An oral antimicrobial is more convenient than parenteral therapy and is preferable as long as clinical efficacy and safety can be assured. Oral fluoroquinolones are an attractive alternative for the treatment of complicated UTI in children, and safety must always be a factor in considering their use in this population. Although the role of fluoroquinolones in pediatric UTI is still under investigation, the limited data available demonstrate a likelihood of efficacy and safety.

Office laboratory procedures, office economics, parenting and parent education, and urinary tract infection

Four areas of pediatric office practice are again reviewed: office laboratory procedures, office economics, parenting and parent education, and urinary tract infection. Screening for celiac disease and the use of rapid antigen testing for extrapharyngeal group A Streptococcus infections are included in office laboratory procedures. Utilization of health care among patients with public insurance, electronic medical records, billing among pediatric residents, and satisfaction surveys are reviewed in office economics. Challenges related to breastfeeding, obesity management and timely immunizations are covered within parenting and parent education. Finally, the use of an augmented urinalysis and a discussion of imaging for first febrile urinary tract infections are included in the area of urinary tract infection.

Incidence of New Renal Parenchymal Inflammatory Changes Following Breakthrough Urinary Tract Infection in Patients With Vesicoureteral Reflux Treated With Antibiotic Prophylaxis: Evaluation by 99M Technetium Dimercapto-Succinic Acid Renal Scan

PURPOSE

Breakthrough urinary tract infections (UTI) are considered an indication for surgical intervention in children with vesicoureteral reflux (VUR) with the goal of preventing new or progressive renal scarring. We assessed the incidence of new renal parenchymal inflammatory changes following breakthrough UTI in patients on antibiotic prophylaxis for VUR.

MATERIALS AND METHODS

We prospectively analyzed 38 patients (62 refluxing renal units) with VUR. All patients experienced a culture documented breakthrough UTI (greater than 100,000 cfu/ml) while taking antibiotic prophylaxis. Dimercapto-succinic acid (DMSA) scans were obtained 4 to 6 weeks after UTI to detect new renal inflammatory changes and all scans were reviewed by the same pediatric nuclear medicine specialist (MM). To avoid misinterpretation of preexistent renal scarring for acute inflammation, new pyelonephritis was confirmed by comparison to prior DMSA scan.

RESULTS

Of 38 patients 14 (38%) had preexistent renal scarring but only 1 (7%) manifested new changes on DMSA scan. Of the remaining 24 patients with normal baseline studies 3 (12.5%) had changes after UTI. Overall, only 4 patients (10.5%) manifested new changes on DMSA scan. Three additional patients who did not have a baseline scan for comparison demonstrated unequivocal changes of acute pyelonephritis on DMSA scan, increasing the incidence to 17% (7 of 41). Of the patients 7 (17%) underwent surgical correction of reflux and 34 (83%) were maintained on antibiotic prophylaxis.

CONCLUSIONS

Of patients with VUR who experienced a single breakthrough UTI while on antibiotic prophylaxis, at most only 17% had renal inflammatory changes on acute DMSA scan. Our findings endorse the usefulness of DMSA scan in tailoring management of VUR and breakthrough UTI cases, and lend support to continued nonoperative management for the majority.

Long-term follow-up of women hospitalized for acute pyelonephritis

Long-term outcome of acute pyelonephritis (AP) in adults is unknown. We evaluated the frequency of renal damage 10-20 years after hospitalization for AP in adult women and the utility of technetium Tc 99m-labeled dimercaptosuccinic acid (Tc 99m-DMSA) scanning for detection of renal scars; 63 of 203 women hospitalized with AP during 1982-1992 were included in the study. Tc 99m-DMSA scanning detected renal scarring in 29 women (46%). Multivariate analysis showed that pregnancy and hypoalbuminemia (albumin level, <3.2 g/dL) at hospitalization were independent risk factors for subsequent development of renal scars. At follow-up, hypertension was observed in approximately one-fifth of patients, regardless of renal scarring status. Four women with scars had a glomerular filtration rate of < or =75 mL/min; none of them developed severe renal impairment. In conclusion, the risk of developing renal scarring after AP in adult women is high. However, clinically relevant renal damage is rare 10-20 years after AP. Tc 99m-DMSA scanning is useful for detecting renal scars in adults but is not routinely needed in practice.