Technical report: urinary tract infections in febrile infants and young children. The Urinary Tract Subcommittee of the American Academy of Pediatrics Committee on Quality Improvement

Contamination rates of different urine collection methods for the diagnosis of urinary tract infections in young children: an observational cohort study

AIMS

  The optimal method for diagnostic collection of urine in children is unclear. National Institute of Health and Clinical Excellence recommend specimens taken by clean catch urine (CCU) for identification of urinary tract infection (UTI). We investigated contamination rates for CCU, suprapubic aspiration (SPA), catheter specimen urine (CSU) and bag specimen urine (BSU) collections.

METHOD

  Retrospective observational cohort study with review of microbiology data and medical records at a large tertiary children's hospital. We reviewed urine culture growth from consecutive first urine specimens of children aged <2 years, over a 3-month period in 2008. Patient demographics, collection method, location (emergency department, inpatient ward), culture growth, history of UTI, urogenital tract abnormality and antibiotic use were assessed. Contamination rates for collection methods were compared using logistic regression.

RESULTS

  Urine culture specimens of 599 children (mean age 7.0 months, 54% male) were included. There were 34% CCU, 16% CSU, 14% SPA, 2% BSU and 34% with unknown sample method. Contamination rates were 26% in CCU, 12% in CSU (odds ratio (OR) 0.4, 95% confidence interval (CI) 0.2-0.8) and 1% in SPA (OR 0.03 95% CI 0.0-0.3). Concurrent antibiotics use was associated with a lower contamination rate. Contamination rates were not associated with age, sex, location, history of UTI or urogenital abnormalities.

CONCLUSION

  Contamination rates in CCU are much higher than in CSU and SPA samples. Ideally, SPA should be used for microbiological assessment of urine in young children. Collection procedures need to be optimised if CCU is used.

The diagnosis of urinary tract infections in young children (DUTY): protocol for a diagnostic and prospective observational study to derive and validate a clinical algorithm for the diagnosis of UTI in children presenting to primary care with an acute illness

Background

Urinary tract infection (UTI) is common in children, and may cause serious illness and recurrent symptoms. However, obtaining a urine sample from young children in primary care is challenging and not feasible for large numbers. Evidence regarding the predictive value of symptoms, signs and urinalysis for UTI in young children is urgently needed to help primary care clinicians better identify children who should be investigated for UTI. This paper describes the protocol for the Diagnosis of Urinary Tract infection in Young children (DUTY) study. The overall study aim is to derive and validate a cost-effective clinical algorithm for the diagnosis of UTI in children presenting to primary care acutely unwell.

Methods/design

DUTY is a multicentre, diagnostic and prospective observational study aiming to recruit at least 7,000 children aged before their fifth birthday, being assessed in primary care for any acute, non-traumatic, illness of ≤ 28 days duration. Urine samples will be obtained from eligible consented children, and data collected on medical history and presenting symptoms and signs. Urine samples will be dipstick tested in general practice and sent for microbiological analysis. All children with culture positive urines and a random sample of children with urine culture results in other, non-positive categories will be followed up to record symptom duration and healthcare resource use. A diagnostic algorithm will be constructed and validated and an economic evaluation conducted.

The primary outcome will be a validated diagnostic algorithm using a reference standard of a pure/predominant growth of at least >10³, but usually >10⁵ CFU/mL of one, but no more than two uropathogens.

We will use logistic regression to identify the clinical predictors (i.e. demographic, medical history, presenting signs and symptoms and urine dipstick analysis results) most strongly associated with a positive urine culture result. We will then use economic evaluation to compare the cost effectiveness of the candidate prediction rules.

Discussion

This study will provide novel, clinically important information on the diagnostic features of childhood UTI and the cost effectiveness of a validated prediction rule, to help primary care clinicians improve the efficiency of their diagnostic strategy for UTI in young children.

Urinary proteome analysis to exclude severe vesicoureteral reflux

OBJECTIVES

High-grade vesicoureteral reflux (VUR, grade IV or V) is a risk factor for renal scarring, impaired renal function, and arterial hypertension. Voiding cystourethrography is the gold standard for detecting the severity of VUR. High-grade VUR is present in the minority of children with urinary tract infection (UTI), thus exposing the majority to invasive diagnostics that have no surgical consequence. We therefore aimed at establishing a noninvasive test to identify children with high-grade VUR.

METHODS

In a case-control study, a specific urinary proteome pattern was established by capillary electrophoresis coupled to mass spectrometry in 18 patients with primary VUR grade IV or V, distinguishing these from 19 patients without VUR after UTI. This proteome pattern was independently validated in a blinded cohort of 17 patients with VUR grade IV or V and 19 patients without VUR.

RESULTS

Sensitivity in detecting VUR grade IV or V in the blinded study was 88%, specificity was 79%. The test's accuracy was independent of age, gender, and grade of VUR in the contralateral kidney. The odds ratio of suffering from VUR grade IV or V when tested positive was 28 (95% confidence interval: 4.5 to 176.0).

CONCLUSIONS

This noninvasive test is ready for prospective validation in large cohorts with the aim of identifying those children with UTI and hydronephrosis in need of further invasive diagnostics, such as voiding cystourethrography, thus sparing most children without pathologic urinary proteome patterns from additional diagnostics.

Procalcitonin is a predictor for high-grade vesicoureteral reflux in children: meta-analysis of individual patient data

OBJECTIVE

To assess the predictive value of procalcitonin, a serum inflammatory marker, in the identification of children with first urinary tract infection (UTI) who might have high-grade (≥3) vesicoureteral reflux (VUR).

STUDY DESIGN

We conducted a meta-analysis of individual data, including all series of children aged 1 month to 4 years with a first UTI, a procalcitonin (PCT) level measurement, cystograms, and an early dimercaptosuccinic acid scan.

RESULTS

Of the 152 relevant identified articles, 12 studies representing 526 patients (10% with VUR ≥3) were included. PCT level was associated with VUR ≥3 as a continuous (P = .001), and as a binary variable, with a 0.5 ng/mL preferred threshold (adjusted OR, 2.5; 95% CI, 1.1 to 5.4). The sensitivity of PCT ≥0.5 ng/mL was 83% (95% CI, 71 to 91) with 43% specificity rate (95% CI, 38 to 47). In the subgroup of children with a positive results on dimercaptosuccinic acid scan, PCT ≥0.5 ng/mL was also associated with high-grade VUR (adjusted OR, 4.8; 95% CI, 1.3 to 17.6).

CONCLUSIONS

We confirmed that PCT is a sensitive and validated predictor strongly associated with VUR ≥3, regardless of the presence of early renal parenchymal involvement in children with a first UTI.

Urinary tract infection: clinical practice guideline for the diagnosis and management of the initial UTI in febrile infants and children 2 to 24 months

OBJECTIVE

To revise the American Academy of Pediatrics practice parameter regarding the diagnosis and management of initial urinary tract infections (UTIs) in febrile infants and young children.

METHODS

Analysis of the medical literature published since the last version of the guideline was supplemented by analysis of data provided by authors of recent publications. The strength of evidence supporting each recommendation and the strength of the recommendation were assessed and graded.

RESULTS

Diagnosis is made on the basis of the presence of both pyuria and at least 50,000 colonies per mL of a single uropathogenic organism in an appropriately collected specimen of urine. After 7 to 14 days of antimicrobial treatment, close clinical follow-up monitoring should be maintained to permit prompt diagnosis and treatment of recurrent infections. Ultrasonography of the kidneys and bladder should be performed to detect anatomic abnormalities. Data from the most recent 6 studies do not support the use of antimicrobial prophylaxis to prevent febrile recurrent UTI in infants without vesicoureteral reflux (VUR) or with grade I to IV VUR. Therefore, a voiding cystourethrography (VCUG) is not recommended routinely after the first UTI; VCUG is indicated if renal and bladder ultrasonography reveals hydronephrosis, scarring, or other findings that would suggest either high-grade VUR or obstructive uropathy and in other atypical or complex clinical circumstances. VCUG should also be performed if there is a recurrence of a febrile UTI. The recommendations in this guideline do not indicate an exclusive course of treatment or serve as a standard of care; variations may be appropriate. Recommendations about antimicrobial prophylaxis and implications for performance of VCUG are based on currently available evidence. As with all American Academy of Pediatrics clinical guidelines, the recommendations will be reviewed routinely and incorporate new evidence, such as data from the Randomized Intervention for Children With Vesicoureteral Reflux (RIVUR) study.

CONCLUSIONS

Changes in this revision include criteria for the diagnosis of UTI and recommendations for imaging.

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.

Concomitant vesicoureteral reflux and gastroesophageal reflux: an analytic cross-sectional study

PURPOSE

Vesicoureteral reflux (VUR) and Gastroesophageal reflux (GER) are both common disorders in children and could be associated with significant morbidities. Although they appear to be separate entities, their natural history and underlying pathophysiology are the same and they both tend to resolve over time. We aimed to appraise their concurrent occurrence and prevalence of GER in VUR patients to understand whether they can be considered different manifestations of a syndrome mainly caused by developmental delay resulting in dysfunction of the sphincters.

METHODS

Totally, 174 children ≤ 2 years of age were enrolled and 87 of them with primary VUR constituted patients group. The rest of the cases with the same age and sex distribution entered control group. All the study population underwent ultrasonographic evaluation to detect GER.

RESULTS

GER was more frequent in patients with primary VUR. GER was more prevalent in higher grades of VUR. We observed higher prevalence of GER and higher grades of VUR in younger infants demonstrating the tendency of both conditions to resolve overtime. Bilateral VUR was more prevalent among patients with higher grades of VUR. GER was more prevalent in patients with bilateral VUR and Prevalence of bilateral VUR decreased with increase in age. These findings show that the chance of concomitant GER and VUR is higher in children with more severe developmental defect of sphincters.

CONCLUSIONS

Regarding the higher prevalence of GER among VUR patients and correlation of VUR severity with co-occurrence of GER, besides the natural tendency of both conditions to resolve overtime, they may be considered parts of developmental delay syndrome of sphincters.

Decision Modeling of Disagreements

Purpose. To identify core disagreements between pediatric hematologists who would treat children with idiopathic thrombocytopenic purpura (ITP) on initial presentation (“Treaters”) and those who would treat by observation (“Observers”), to determine whether each group’s preferred stance was consistent with each individual’s detailed perceptions, and to identify key variables in each stance. Methods. A decision model was constructed in collaboration with experts, and a detailed questionnaire was presented to a nationally representative committee of 25 pediatric hematologists. A full decision tree was specified for each respondent. Results. Nineteen (76%) experts responded; based on preference for initial treatment, 9 were Treaters and 10 Observers. Of the 30 probability/effectiveness variables, 8—almost all concerning treatment effectiveness—had at least one statistically-significant difference between the 2 groups regarding low, best, or high estimates. To convince Observers that treatment is effective would take a clinical trial with between 39 000 and 87 000 participants; to convince Treaters that treatment is not effective enough, between 97 000 and 114 000 participants. Observers’ calculated numbers needed to treat (NNTs) of about 150 000 are more consistent ( P = 0.0023) with their elicited maximum NTTs of about 500. Conclusion. Physicians not specifically trained provided enough data to specify complete individual decision models. From the estimates provided, no practical clinical trial could convince hematologists who would treat children on initial presentation with ITP just to simply observe them or could convince those who would just observe to instead treat with available agents. Perceived burdens could be better characterized, perhaps by including parental perceptions and preferences.

Risk factors for recurrent urinary tract infection in infants with vesicoureteral reflux during prophylactic treatment: effect of delayed contrast passage on voiding cystourethrogram

OBJECTIVES

To investigate the risk factors for recurrent urinary tract infection (UTI) in infants with vesicoureteral reflux (VUR) because little is known regarding the risk factors for breakthrough infection.

METHODS

We compared children with infantile VUR with (20 boys, mean age 2.7 months) and without (20 boys and 4 girls, mean age 4.7 months) recurrent UTI. The factors compared included sex, timing of UTI episode, degree and bilaterality of the reflux, hydronephrosis, renal scar, associated congenital anomalies, voiding dysfunction, and delayed ureteral excretion of refluxed contrast on the voiding cystourethrogram.

RESULTS

Univariate Cox survival-time regression analysis showed that a younger mean age at the first UTI, bilateral reflux, and grade 4-5 VUR and hydronephrosis on the initial ultrasound scan significantly increased the risk of recurrent UTI (P<.05 each). On multivariate analysis, high-grade (P=.009) and bilateral (P=.016) VUR were independently associated with an increased risk of recurrent UTI. Of the infants with and without recurrent UTI, 80% and 0%, respectively, presented with high-grade VUR, as shown by delayed contrast passage on the voiding cystourethrogram. A urodynamic study of 11 infants with recurrent UTI showed decreased bladder capacity in 2 infants and a larger residual volume in 1 infant.

CONCLUSIONS

During the first year after birth, high-grade and bilateral VUR significantly increased the risk of recurrent UTI. Delayed contrast passage on the voiding cystourethrogram was significantly associated with an increased risk of recurrent UTI.

Procalcitonin: a key marker in children with urinary tract infection

Urinary tract infections (UTIs) are the most common source of bacterial infections among young febrile children. Accurate diagnosis of acute pyelonephritis (APN) and vesicoureteral reflux (VUR) is important because of their association with renal scarring, leading in the cases to long-term complications. However, the gold standard examinations for both are either DMSA scan (for APN and scar) or cystography (for VUR) and present limitations (feasibility, pain, cost, etc.). Procalcitonin, a reliable marker of bacterial infections, was demonstrated to be a good predictor of both renal parenchymal involvement in the acute phase and late renal scars. Furthermore, it was also found to be associated with high-grade VUR and was the key tool of a clinical decision rule to predict high-grade VUR in children with a first UTI. Therefore, procalcitonin may certainly be found playing a role in the complex and still debated picture of which examination should be performed after UTI in children.

Pediatric urologic conditions, including urinary infections

Genitourinary complaints are common in children, and the busy primary care provider must determine initial treatment and assess need for specialty referral. Many complaints are self-limited, but some represent disorders that can threaten organ function. In this article, an initial approach in the primary care office and a guide to specialty referral for pediatric urologic conditions of the urinary tract, male genitalia, and female genitalia are suggested.

Pediatric urinary tract infections: an analysis of hospitalizations, charges, and costs in the USA

This study evaluates the impact of pediatric urinary tract infection (UTI)s on the economy and inpatient healthcare utilization in the USA. A retrospective analysis of patient demographics and hospital economics was performed on children less than 18 years of age admitted with a UTI between 2000 and 2006 using the Healthcare Cost and Utilization Project Kids' Inpatient Database. Our results were stratified as follows. Hospital admissions-nearly 50,000 children/year were admitted with a UTI. Pediatric UTIs represented 1.8% of all pediatric hospitalizations. Seventy-three percent of patients were female and 40% were under 1 year of age. Payer information-from 2000 to 2006, pediatric insurance coverage shifted from the private sector to the public sector. Hospital cost-in 2000, estimated hospital costs for UTIs were $2,858 per hospitalization and rose to $3,838 by 2006. Mean hospital charges increased from $6,279 to $10,489 per stay. By 2006, aggregate hospital charges exceeded $520 million. Our results indicate that UTIs are among the most common pediatric admission diagnoses. Hospitalization is more common in females and younger children. Since 2000, hospital charges for UTIs increased disproportionately to hospital costs. Over time, more children hospitalized with a UTI depend on public agencies to cover healthcare expense. More efforts are needed to evaluate cost-effective strategies for evaluation and treatment of UTIs.

Evaluating different imaging strategies in children after first febrile urinary tract infection

We conducted a retrospective multicenter review to estimate the prevalence of urological abnormalities in Chinese children with first febrile urinary tract infection (UTI) and to evaluate the selective imaging strategy recommended by the NICE guideline for detecting underlying abnormalities. Atypical UTI was defined as in the NICE UTI guideline. Overall, 576 boys and 244 girls aged below 24 months were reviewed. All underwent ultrasound (US) and micturating cystourethrogram (MCUG) and 612 underwent DMSA scans. US was abnormal in 73 (8.9%) and vesicoureteral reflux was shown in 195 patients (23.8%). A total of 126 patients were considered to have remediable urological abnormalities requiring additional surgical or medical interventions. The NICE guideline yielded excellent negative predictive values (NPV) of 100-94.4% in girls but 91% in boys. If all boys underwent US and DMSA and only those with atypical UTI or abnormal US or DMSA proceeded to MCUG, then the NPV increased to 95.2% and 97.4% for boys aged below and above 6 months, respectively. These revised strategies would substantially save invasive studies-DMSA and MCUG in 27 and 74% of girls aged below and above 6 months, respectively, or MCUG in 23 and 59% of boys aged below and above 6 months, respectively.

DMSA scan for revealing vesicoureteral reflux in young children with urinary tract infection

OBJECTIVES

The objective of this study was to assess the ability of acute dimercaptosuccinic acid (DMSA) scintigraphy for revealing vesicoureteral reflux (VUR) in young children after a first febrile urinary tract infection (UTI).

METHODS

Children aged<or=24 months and were admitted with a first febrile UTI during a 5-year period were evaluated. The ability of acute DMSA scintigraphy to reveal dilating (grades 3-5) or severe (grades 4-5) VUR was assessed by comparing DMSA scan findings with those of voiding cystourethrography.

RESULTS

Of the 296 children included, 46 had dilating and 25 severe VUR. Abnormal DMSA scan results were associated with an odds ratio of 4.36 for dilating and 5.50 for severe VUR. For detecting dilating VUR, the area under the curve (AUC) was 0.68, the positive likelihood ratio (LR) was 2.00, and the negative LR was 0.46; for severe VUR, those values were 0.69, 2.10, and 0.38, respectively. Children with abnormal DMSA scan results combined with abnormal ultrasonography had an odds ratio of 3.60 for dilating and 6.32 for severe VUR. Despite normal findings on both investigations, 12 children had dilating and 4 severe VUR. For dilating VUR, the area under the (AUC) was 0.65, the positive LR was 1.70, and the negative LR was 0.47; for severe VUR, the values were 0.69, 1.90, and 0.29, respectively.

CONCLUSIONS

Our data suggest that acute DMSA scintigraphy has limited overall ability in identifying VUR and should not be endorsed as replacement for voiding cystourethrography in the evaluation of young children with a first febrile UTI.

Duration of fever affects the likelihood of a positive bag urinalysis or catheter culture in young children

OBJECTIVE

To test the hypothesis that there will be a clinically significant rise in the proportion of positive bag urinalyses and catheter cultures in young children with increasing duration of fever.

STUDY DESIGN

This was a prospective cohort study of 818 infants and children age 3-36 months presenting to a tertiary care emergency department with documented fever without source. Following the documentation of fever from < 1 to > or = 5 days, bag specimens were collected for urinalysis. The primary outcome was the yield of positive bag dipsticks by day, defined as positive for nitrates or more than trace leukocyte esterase. The secondary outcome was positive catheter cultures on each day of fever.

RESULTS

Positive bag urinalyses increased with duration of fever: 14.8% (35/237) on day 1 versus 26.4% (43/163) on day 3 (relative risk [RR] = 1.8; 95% confidence interval [CI] = 1.2-2.7; P = .004). Positive catheter cultures increased in the same fashion: 4.8% (11/229) on day 1 versus 12.6% (20/159) on day 3 (RR = 2.6; 95% CI = 1.3-5.3; P = .005).

CONCLUSIONS

The yield of positive bag urinalyses and catheter cultures increased significantly in children with fever of 3 days or longer duration.

How do Dutch general practitioners diagnose children's urinary tract infections?

OBJECTIVE

To study which tests general practitioners used to diagnose a urinary tract infection (UTI) in children and which patient characteristics were associated with test choice.

DESIGN

Retrospective chart review on the diagnosis of UTIs in children in Dutch general practices who were diagnosed as having a UTI. A total of 49 general practices participated in the study, and provided information on 148 children aged 0-12 years old.

RESULTS

The nitrite test, which is recommended as first step, was performed in 87% of the children during the first contact. Less than 30% of the children had a dipslide and 37% a cultured urine. About half of all children with a UTI diagnosis had a follow-up contact in general practice, and an average of 83% of these children had their urine tested. The recommended test, a dipslide, was performed in 26% of the children with a follow-up contact. Patient age and UTI history were associated with choice of test.

CONCLUSIONS

The diagnostic procedures for UTIs in children in general practices could be improved, with focus on the importance of an accurate UTI diagnosis in all children, and explaining which tests should be performed and what the test results mean.

Management of childhood urinary tract infections: an economic modeling study

Childhood urinary tract infections (UTIs) can lead to renal scarring and ultimately to terminal renal failure, which has a high impact on quality of life, survival, and health-care costs. Variation in the treatment of UTIs between practices is high.

OBJECTIVE

To assess the cost-effectiveness of a maximum care model for UTIs in children, implying more testing and antibiotic treatment, compared with current practice in primary care in The Netherlands.

METHODS

We performed a probabilistic modeling study using Markov models. Figures used in the model were derived from a systematic review of the research literature. Multidimensional Monte Carlo simulation was used for the probabilistic analyses.

RESULTS

Maximum care gained 0.00102 (males) and 0.00219 (girls) QALYs (quality-adjusted life-years) and saved 42.70 euro (boys) and 77.81 euro (girls) in 30 years compared with current care, and was thus dominant. Net monetary benefit of maximum care ranged from 20 euro to 200 euro for a willingness to pay for a QALY ranging from 0 euro to 80,000 euro, respectively. Maximum care was also dominant over improved current care, although less dominant than to current care.

CONCLUSIONS

This study suggested that maximum care for childhood UTI was dominant in the long run to current care, meaning that it delivered more quality of life at lower costs. Nevertheless, making firm conclusions is not possible, given the limitations of the input data.

[Urinary tract infections in children]

Urinary tract infection (UTI) is relatively frequent in children. The younger the child is, the more symptoms are atypical. UTI is often associated with functional or malformative uropathy, such as vesico-ureteral reflux or obstruction. Appropriate imaging studies should be carried out in every infected child. The prognosis of uncomplicated UTI is very good, but is less favorable when the UTI is associated with urological abnormalities. Development of pyelonephritic scars can lead to kidney scarring, for which the occurrence of intrarenal reflux is probably responsible . Short-term treatment is recommended for uncomplicated UTI. Uncomplicated UTI with frequent relapses requires prophylactic chemotherapy; this treatment should also be considered when UTI is associated with vesico-ureteral reflux. Surgery is indicated in the presence of major urological malformations. Whether medical or surgical, the treatment of UTI should be followed by urine cultures whenever the child presents with fever. The antibiotic treatment of acute pyelonephritis must be started immediately, preferentially by intravenous route. A switch to oral treatment can be made after obtaining the results of the antibiogram. UTI represents a major risk in neonates; it should preferably be managed in specialized centers.

Harmonic voiding urosonography with a second-generation contrast agent for the diagnosis of vesicoureteral reflux

BACKGROUND

Voiding urosonography with harmonic imaging (VUS HI) has been introduced as a sensitive and radiation-free imaging method for the diagnosis and follow-up of vesicoureteral reflux (VUR) in children.

OBJECTIVE

The purpose of this study was to evaluate the sensitivity of VUS HI using a second-generation US contrast agent compared to standard voiding cystourethrography (VCUG).

MATERIALS AND METHODS

A total of 228 children with 463 kidney-ureter units (KUUs) underwent two cycles of VUS HI and two cycles of VCUG at the same session. VUS HI was performed after intravesical administration of 1 ml of a second-generation US contrast agent (sulphur-hexafluoride gas microbubbles, SonoVue, Bracco, Italy). For statistical analysis we used McNemar's test, Student's t-test and k coefficient tests.

RESULTS

VUR was shown in 161/463 (34.7%) KUUs, 57 by both methods, 90 only by VUS, and 14 only by VCUG. Concordance in findings regarding the presence or absence of VUR was found in 359/463 (77.5%) KUUs (k=0.40). The difference in the detection rate of reflux between the two methods was significant (P<0.01). More importantly, reflux missed by VCUG was of higher grade (2 grade I, 65 grade II, 19 grade III, 4 grade IV) than that missed by VUS (8 grade I, 5 grade II, 1 grade III).

CONCLUSION

VUS HI and a second-generation contrast agent improved the identification of reflux in children. Our data reveal a higher sensitivity of the method compared to VCUG. Thus it can be used as an alternative radiation-free imaging method.

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.

Interleukin 8 is a surrogate marker for rapid diagnosis of bacteriuria

Urinary tract infection (UTI) is one of the most common sources of infection in children under 5. Rapid diagnosis is a need to avoid complications of UTI. The goal of the present study was to evaluate the use of urinary interleukin 8 (IL8) as a rapid laboratory method for diagnosis of UTI. A total of 116 children were included in the study. They were complaining of different diseases with pyuria. In addition twenty healthy children were included as control subjects. Urine samples were subjected to full chemical, cytological and bacteriological examinations. In addition, urinary IL8 was measured. Patients showed significantly elevated urine IL-8 levels (80-820 pg/ml) compared to control subjects (6-10 pg/ml) (p < 0.0001). There was significant correlation between interleukin 8 level and white blood cells counts in urine (p = 0.039). The mean +/- SD of urinary IL-8 was significantly increased 165.8 +/- 115.1 in urine with bacterial growth (Staphylococcus species and Escherichia coli) p < 0.001 than in urine without growth. Urine with Escherichia coli (E. coli) growth had significantly higher IL 8 level than growth with other types of organisms. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value had higher level for IL8 compared to other parameters in urine examination i.e., nitrite, WBCs and RBCs (85.7%, 60%, 64%, 87%, 64% respectively). This study highlights that bacteriuria is associated with higher level of urinary interleukin 8 than pyuria without bacteriuria. Thus from this study we can conclude that IL8 can be used as rapid surrogate marker for rapid laboratory diagnosis of urosepsis.

Is antibiotic prophylaxis in children with vesicoureteral reflux effective in preventing pyelonephritis and renal scars? A randomized, controlled trial

OBJECTIVES

There has been intense discussion on the effectiveness of continuous antibiotic prophylaxis for children with vesicoureteral reflux, and randomized, controlled trials are still needed to determine the effectiveness of long-term antibiotics for the prevention of acute pyelonephritis. In this multicenter, open-label, randomized, controlled trial, we tested the effectiveness of antibiotic prophylaxis in preventing recurrence of pyelonephritis and avoiding new scars in a sample of children who were younger than 30 months and vesicoureteral reflux.

METHODS

One hundred patients with vesicoureteral reflux (grade II, III, or IV) diagnosed with cystourethrography after a first episode of acute pyelonephritis were randomly assigned to receive antibiotic prophylaxis with sulfamethoxazole/trimethoprim or not for 2 years. The main outcome of the study was the recurrence of pyelonephritis during a follow-up period of 4 years. During follow-up, the patients were evaluated through repeated cystourethrographies, renal ultrasounds, and dimercaptosuccinic acid scans.

RESULTS

The baseline characteristics in the 2 study groups were similar. There were no differences in the risk for having at least 1 pyelonephritis episode between the intervention and control groups. At the end of follow-up, the presence of renal scars was the same in children with and without antibiotic prophylaxis.

CONCLUSIONS

Continuous antibiotic prophylaxis was ineffective in reducing the rate of pyelonephritis recurrence and the incidence of renal damage in children who were younger than 30 months and had vesicoureteral reflux grades II through IV.

Prevalence of urinary tract infection in childhood: a meta-analysis

BACKGROUND

Knowledge of baseline risk of urinary tract infection can help clinicians make informed diagnostic and therapeutic decisions. We conducted a meta-analysis to determine the pooled prevalence of urinary tract infection (UTI) in children by age, gender, race, and circumcision status.

METHODS

MEDLINE and EMBASE databases were searched for articles about pediatric urinary tract infection. Search terms included urinary tract infection, cystitis, pyelonephritis, prevalence and incidence. We included articles in our review if they contained data on the prevalence of UTI in children 0-19 years of age presenting with symptoms of UTI. Of the 51 articles with data on UTI prevalence, 18 met all inclusion criteria. Two evaluators independently reviewed, rated, and abstracted data from each article.

RESULTS

Among infants presenting with fever, the overall prevalence (and 95% confidence interval) of UTI was 7.0% (CI: 5.5-8.4). The pooled prevalence rates of febrile UTIs in females aged 0-3 months, 3-6 months, 6-12 months, and >12 months was 7.5%, 5.7%, 8.3%, and 2.1% respectively. Among febrile male infants less than 3 months of age, 2.4% (CI: 1.4-3.5) of circumcised males and 20.1% (CI: 16.8-23.4) of uncircumcised males had a UTI. For the 4 studies that reported UTI prevalence by race, UTI rates were higher among white infants 8.0% (CI: 5.1-11.0) than among black infants 4.7% (CI: 2.1-7.3). Among older children (<19 years) with urinary symptoms, the pooled prevalence of UTI (both febrile and afebrile) was 7.8% (CI: 6.6-8.9).

CONCLUSIONS

Prevalence rates of UTI varied by age, gender, race, and circumcision status. Uncircumcised male infants less than 3 months of age and females less than 12 months of age had the highest baseline prevalence of UTI. Prevalence estimates can help clinicians make informed decisions regarding diagnostic testing in children presenting with signs and symptoms of urinary tract infection.

Imaging in urinary tract infections: current strategies and new trends

The aim of imaging in a child with urinary tract infection (UTI) is to detect abnormalities that require appropriate treatment or findings that can be acted on to prevent development of complications (hypertension, chronic renal failure or pregnancy-related complications). Imaging protocols in pediatric urinary tract infections are evolving. From strategies based on extensive investigations in all children younger than 7 years of age, we are slowly moving to imaging strategies focused on children at risk of developing renal damage and possibly long-term complications. The article provides an overview on urinary tract infections, their complications and the use of imaging in their management. The different imaging strategies in children with UTIs (including the recommendation of excluding from imaging certain groups of patients) still needs full evaluation. It is interesting to note, however, a slow move from wide use of cystography in all children with UTI, which has been standard practice for many years but was probably not based on solid scientific evidence, toward a more focused use of cystograms in specific groups of children.

Imaging and treatment strategies for children after first urinary tract infection

PURPOSE OF REVIEW

To highlight recent controversies regarding the rationale and effectiveness of imaging and treatment strategies for children who experience a first urinary tract infection.

RECENT FINDINGS

The yield of renal ultrasound for children who have had a first urinary tract infection is relatively low, and the most commonly identified abnormalities are of unclear clinical significance. If concerned about renal ultrasound abnormalities, clinicians should not be reassured by a normal late trimester prenatal ultrasound because its negative predictive value is not sufficiently high. Vesicoureteral reflux is neither necessary nor sufficient for developing renal scars. Some pyelonephritis and renal scarring may be related to vesicoureteral reflux that is missed by standard voiding cystourethrogram but detectable during positional instillation of contrast cystography. Dimercaptosuccinic acid scans provide important information about presence of pyelonephritis and renal scars, and have high negative predictive value for ruling out high-grade (III-V) vesicoureteral reflux. Antimicrobial prophylaxis may not be effective for preventing recurrent infections and may result in antimicrobial resistance. Endoscopic therapy (Deflux) has demonstrated moderate success in correcting vesicoureteral reflux, but little is known about its impact on recurrent infection and renal scarring.

SUMMARY

Debate continues about optimal imaging strategies after first urinary tract infection. More research is needed on the effectiveness of interventions designed to prevent recurrent infections and renal scarring.

Evaluating the specificity of a new type of urine collection bag for infants

OBJECTIVE

For diagnosing urinary tract infection (UTI) in infants, the urine collection bag is a common sampling method. It has several advantages versus other methods but a high risk of contamination makes culture results difficult to evaluate. Previous studies report a specificity ranging from 14% to 84%. The objective of this study was to evaluate the specificity of a new type of urine collection bag.

METHOD

Urine samples were collected from healthy infants with a new type of collection bag. As the urine is expected to be sterile, any bacterial growth would be considered a contamination.

RESULTS

Forty-four samples were included: 40 samples showed <10,000 cfu/ml of mixed growth or no growth at all, three samples showed <10,000 cfu/ml of single-strain growth and one sample showed >10,000<100,000 cfu/ml of single-strain growth. No samples showed any growth >100,000 cfu/ml.

CONCLUSION

According to Kass criteria, 97.7% of the samples would exclude a UTI and 2.3% would be considered inconclusive. None of the samples had a contamination level that, falsely, would be interpreted as positive. Further studies will be valuable as a specificity of 97.7% suggests that this collection device could give the clinician a non-invasive option for diagnosing UTI in infants.

Antibiotic treatment for pyelonephritis in children: multicentre randomised controlled non-inferiority trial

OBJECTIVE

To compare the efficacy of oral antibiotic treatment alone with treatment started parenterally and completed orally in children with a first episode of acute pyelonephritis.

DESIGN

Multicentre, randomised controlled, open labelled, parallel group, non-inferiority trial.

SETTING

28 paediatric units in north east Italy.

PARTICIPANTS

502 children aged 1 month to <7 years with clinical pyelonephritis.

INTERVENTION

Oral co-amoxiclav (50 mg/kg/day in three doses for 10 days) or parenteral ceftriaxone (50 mg/kg/day in a single parenteral dose) for three days, followed by oral co-amoxiclav (50 mg/kg/day in three divided doses for seven days). Main outcomes measures Primary outcome was the rate of renal scarring. Secondary measures of efficacy were time to defervescence (<37 degrees C), reduction in inflammatory indices, and percentage with sterile urine after 72 hours. An exploratory subgroup analysis was conducted in the children in whom pyelonephritis was confirmed by dimercaptosuccinic acid (DMSA) scintigraphy within 10 days after study entry.

RESULTS

Intention to treat analysis showed no significant differences between oral (n=244) and parenteral (n=258) treatment, both in the primary outcome (scarring scintigraphy at 12 months 27/197 (13.7%) v 36/203 (17.7%), difference in risk -4%, 95% confidence interval -11.1% to 3.1%) and secondary outcomes (time to defervescence 36.9 hours (SD 19.7) v 34.3 hours (SD 20), mean difference 2.6 (-0.9 to 6.0); white cell count 9.8x10(9)/l (SD 3.5) v 9.5x10(9)/l (SD 3.1), mean difference 0.3 (-0.3 to 0.9); percentage with sterile urine 185/186 v 203/204, risk difference -0.05% (-1.5% to 1.4%)). Similar results were found in the subgroup of 278 children with confirmed acute pyelonephritis on scintigraphy at study entry.

CONCLUSIONS

Treatment with oral antibiotics is as effective as parenteral then oral treatment in the management of the first episode of clinical pyelonephritis in children.

TRIAL REGISTRATION

Clinical Trials NCT00161330 [ClinicalTrials.gov].

Imaging strategies for vesicoureteral reflux diagnosis

The prevalence of vesicoureteral reflux (VUR), although reported to be low in the general population, is high in children with urinary tract infection (UTI), first degree relatives of patients with known VUR and children with antenatal hydronephrosis. In addition, it has been shown that VUR and UTIs are associated with renal scarring, predisposing to serious long-term complications, i.e., hypertension, chronic renal insufficiency and complications of pregnancy. Therefore, diagnostic imaging for the detection of VUR in the high-risk groups of children has been a standard practice. However, none of these associations has been validated with controlled studies, and recently the value of identifying VUR after a symptomatic UTI has been questioned. In addition, several studies have shown that renal damage may occur in the absence of VUR. On the other hand, some patients, mainly males, may have primary renal damage, associated with high-grade VUR, without UTI. Recently, increasing skepticism has been noted concerning how and for whom it is important to investigate for VUR. It has been suggested that the absence of renal lesions after the first UTI in children may rule out VUR of clinical significance and reinforces the redundancy of invasive diagnostic techniques. Therefore, the priority of imaging strategies should focus on early identification of renal lesions to prevent further deterioration.

To clean or not to clean: effect on contamination rates in midstream urine collections in toilet-trained children

OBJECTIVE

Urinary tract infection is one of the most common bacterial infections among children. Difficulty in specimen collection and interpretation of inadequately collected specimens may contribute to misdiagnosis of urinary tract infection. Our objective was to assess the effect of perineal/genital cleaning on bacterial contamination rates of midstream urine collections in toilet-trained children.

METHODS

We conducted a randomized trial in toilet-trained children who presented to a tertiary care pediatric emergency department between November 1, 2004, and October 1, 2005. All toilet-trained children who were between the ages of 2 and 18 years and had a midstream urine sample requested were eligible. Those whose parents consented were cluster-randomized by week to either cleaning or not cleaning the perineum with soap. The risk for a contaminated urine culture (defined as growth of < 10(8) colony-forming units per liter [< 10(5) colony-forming units per milliliter] of a single organism or a mix of > or = 2 organisms) and the risk for a positive urinalysis (defined as a positive leukocyte esterase and/or nitrites on dipstick or > or = 5 white blood cells per high-powered field on a standard microscopic examination) were analyzed by intention to treat.

RESULTS

A total of 350 children were enrolled. The rate of contamination in the cleaning group was 14 (7.8%) of 179 vs 41 (23.9%) of 171 in the noncleaning group. Children who were randomly assigned to cleaning were less likely to have a positive urinalysis (37 of 179 [20.6%]) than those in the noncleaning group (63 of 171 [36.8%]).

CONCLUSIONS

Urine contamination rates are higher in midstream urine that is collected from toilet-trained children when obtained without perineal/genital cleaning. Cleaning may reduce the risk for returning for repeat cultures and for receiving unnecessary antibiotic treatment and investigations.

Phylogenetic groups and virulence factors of Escherichia coli strains causing pyelonephritis in children with and without urinary tract abnormalities

Escherichia coli isolates causing acute pyelonephritis in 93 children (25% with urinary tract abnormalities) were tested for nine virulence factors (papC, papGII, papGIII, sfa/foc, hlyC, cnf1, iucC, fyuA and iroN) and their phylogenetic groups were determined. Isolates lacking papGII were more frequent among patients with urinary tract abnormalities (58% vs. 10%, p 0.0003), as were non-virulent phylogenetic group A isolates (25% vs. 5%, p 0.043). Pyelonephritis caused by less virulent E. coli strains was more frequent among patients with significant urinary tract abnormalities. Further studies are required to determine whether screening for E. coli virulence factors may help to identify children warranting anatomical investigations.

Agreement of decision analyses and subsequent clinical studies in infectious diseases

PURPOSE

Decision analysis techniques can compare management strategies when there are insufficient data from clinical studies to guide decision making. We compared the outcomes of decision analyses and subsequent clinical studies in the infectious disease literature to assess the validity of the conclusions of the decision analyses.

METHODS

A search strategy to identify decision analyses in infectious disease topics published from 1990 to 2005 was developed and performed using PubMed. Abstracts of all identified articles were reviewed, and infectious disease-related decision analyses were retained. Subsequent clinical trials and observational studies that corresponded to these decision analyses were identified using prespecified search strategies. Clinical studies were considered a match for the decision analysis if they assessed the same patient population, intervention, and outcome. Agreement or disagreement between the conclusions of the decision analysis and clinical study were determined by author review.

RESULTS

The initial PubMed search yielded 318 references. Forty decision analyses pertaining to 29 infectious disease topics were identified. Of the 40, 16 (40%) from 13 infectious disease topics had matching clinical studies. In 12 of 16 (75%), conclusions of at least 1 clinical study agreed with those of the decision analysis. Three of the 4 decision analyses in which conclusions disagreed were from the same topic (management of febrile children).

CONCLUSIONS

There was substantial agreement between the conclusions of decision analyses and clinical studies in infectious diseases, supporting the validity of decision analysis and its utility in guiding management decisions.

Ordering of renal tract imaging by paediatricians after urinary tract infection

AIM

To describe paediatricians' reported ordering of renal tract imaging of children following urinary tract infection.

METHODS

This is a piloted self-administered survey. A total of 354 randomly sampled practising paediatricians in Australia participated in the survey. The survey included 12 clinical scenarios that varied with age, gender and fever. Respondents indicated their likelihood of ordering renal ultrasound, micturating cystourethrogram (MCU) and dimercaptosuccinic acid scan (DMSA) from 0 to 100%.

RESULTS

Response rate was 74.6% (264/354). For all clinical scenarios the median probability of ordering an ultrasound was 100% with little variability. For children aged 2 months, likelihood of ordering an MCU was 100%, with little variability, but was 70% for 3-year-olds with fever (45% without fever), and 5% for 6-year-olds with very large variability. Median likelihood of ordering a DMSA was 80% at 2 months, 60% at 3 years and 20% at 6 years (40%, 15%, 5% without fever, respectively). Variability was large for all scenarios and DMSA ordering. Child gender did not influence ordering practices.

CONCLUSIONS

Renal tract imaging practice across paediatricians shows consistent, approximately 100% use of the least invasive modality, ultrasound. In contrast, there is considerable variation in the reported ordering of the more invasive tests MCU and DMSA. Doctors order these tests more in younger children and when fever is present.

Effect of point-of-care influenza testing on management of febrile children

OBJECTIVES

To determine the effect of point-of-care testing (POCT) for influenza on the physician management of febrile children who are at risk for serious bacterial illness (SBI) on the basis of age and temperature and who are presenting to a pediatric emergency department (ED) during an influenza outbreak.

METHODS

Patients 2-3 months of age with temperature of > or = 38 degrees C and patients 3-24 months of age with temperature of > or = 39 degrees C who were presenting to a pediatric ED during an influenza outbreak were enrolled into a prospective, quasi-randomized, controlled trial. Influenza testing was performed on enrolled patients by either the POCT or the standard-testing (ST) methods. The two groups were compared in terms of laboratory testing, chest radiography, antibiotic use, visit-associated costs, pediatric ED lengths of stay, inpatient admission, and return visits to the pediatric ED. Similar analyses also were performed on the resulting subgroups of patients on the basis of method of testing (POCT or ST) and test result (positive or negative).

RESULTS

Of 767 eligible patients, 700 (91%) completed the study. No significant differences were demonstrated between the POCT and ST groups with respect to laboratory tests ordered, chest radiographs obtained, antibiotic administration, inpatient admission, return visits to the pediatric ED, lengths of stay, or visit-associated costs. In the subgroup analysis, the adjusted odds ratios (ORs) for blood culture in influenza test-positive to -negative patients were 0.59 and 0.71 in the POCT and ST groups, respectively (p = 0.088). The adjusted ORs for urine culture in influenza test-positive to -negative patients were 0.46 and 0.67 in the POCT and ST groups, respectively (p = 0.005).

CONCLUSIONS

When using a strategy of performing influenza testing on all patients at risk for SBI who presented to a pediatric ED during an influenza outbreak, the method of testing (POCT or ST) did not appear to significantly alter physician management, cost, or length of stay in the pediatric ED. However, if the interaction of the method of testing and the test result (positive or negative) were considered, a positive POCT for influenza was associated with a significant reduction in orders for urinalyses and urine cultures.

Applying the ALARA concept to the evaluation of vesicoureteric reflux

The voiding cystourethrogram (VCUG) is a widely used study to define lower urinary tract anatomy and to diagnose vesicoureteric reflux (VUR) in children. We examine the technical advances in the VCUG and other examinations for reflux that have reduced radiation exposure of children, and we give recommendations for the use of imaging studies in four groups of children: (1) children with urinary tract infection, (2) siblings of patients with VUR, (3) infants with antenatal hydronephrosis (ANH), and (4) children with a solitary functioning kidney. By performing examinations with little to no radiation, carefully selecting only the children who need imaging studies and judiciously timing follow-up examinations, we can reduce the radiation exposure of children being studied for reflux.