Gabrielle Williams

Antibiotic Prophylaxis and Recurrent Urinary Tract Infection in Children

BACKGROUND Antibiotics are widely administered to children with the intention of preventing urinary tract infection, but adequately powered, placebo-controlled trials regarding efficacy are lacking. This study from four Australian centers examined whether low-dose, continuous oral antibiotic therapy prevents urinary tract infection in predisposed children. METHODS We randomly assigned children under the age of 18 years who had had one or more microbiologically proven urinary tract infections to receive either daily trimethoprim-sulfamethoxazole suspension (as 2 mg of trimethoprim plus 10 mg of sulfamethoxazole per kilogram of body weight) or placebo for 12 months. The primary outcome was microbiologically confirmed symptomatic urinary tract infection. Intention-to-treat analyses were performed with the use of time-to-event data. RESULTS From December 1998 to March 2007, a total of 576 children (of 780 planned) underwent randomization. The median age at entry was 14 months; 64% of the patients were girls, 42% had known vesicoureteral reflux (at least grade III in 53% of these patients), and 71% were enrolled after the first diagnosis of urinary tract infection. During the study, urinary tract infection developed in 36 of 288 patients (13%) in the group receiving trimethoprim-sulfamethoxazole (antibiotic group) and in 55 of 288 patients (19%) in the placebo group (hazard ratio in the antibiotic group, 0.61; 95% confidence interval, 0.40 to 0.93; P = 0.02 by the log-rank test). In the antibiotic group, the reduction in the absolute risk of urinary tract infection (6 percentage points) appeared to be consistent across all subgroups of patients (P > or = 0.20 for all interactions). CONCLUSIONS Long-term, low-dose trimethoprim-sulfamethoxazole was associated with a decreased number of urinary tract infections in predisposed children. The treatment effect appeared to be consistent but modest across subgroups. (Australian New Zealand Clinical Trials Registry number, ACTRN12608000470392.)

The accuracy of clinical symptoms and signs for the diagnosis of serious bacterial infection in young febrile children: prospective cohort study of 15 781 febrile illnesses.

Objectives To evaluate current processes by which young children presenting with a febrile illness but suspected of having serious bacterial infection are diagnosed and treated, and to develop and test a multivariable model to distinguish serious bacterial infections from self limiting non-bacterial illnesses. Design Two year prospective cohort study. Setting The emergency department of The Children’s Hospital at Westmead, Westmead, Australia. Participants Children aged less than 5 years presenting with a febrile illness between 1 July 2004 and 30 June 2006. Intervention A standardised clinical evaluation that included mandatory entry of 40 clinical features into the hospital’s electronic record keeping system was performed by physicians. Serious bacterial infections were confirmed or excluded using standard radiological and microbiological tests and follow-up. Main outcome measures Diagnosis of one of three key types of serious bacterial infection (urinary tract infection, pneumonia, and bacteraemia), and the accuracy of both our clinical decision making model and clinician judgment in making these diagnoses. Results We had follow-up data for 93% of the 15 781 instances of febrile illnesses recorded during the study period. The combined prevalence of any of the three infections of interest (urinary tract infection, pneumonia, or bacteraemia) was 7.2% (1120/15 781, 95% confidence interval (CI) 6.7% to 7.5%), with urinary tract infection the diagnosis in 543 (3.4%) cases of febrile illness (95% CI 3.2% to 3.7%), pneumonia in 533 (3.4%) cases (95% CI 3.1% to 3.7%), and bacteraemia in 64 (0.4%) cases (95% CI 0.3% to 0.5%). Almost all (>94%) of the children with serious bacterial infections had the appropriate test (urine culture, chest radiograph, or blood culture). Antibiotics were prescribed acutely in 66% (359/543) of children with urinary tract infection, 69% (366/533) with pneumonia, and 81% (52/64) with bacteraemia. However, 20% (2686/13 557) of children without bacterial infection were also prescribed antibiotics. On the basis of the data from the clinical evaluations and the confirmed diagnosis, a diagnostic model was developed using multinomial logistic regression methods. Physicians’ diagnoses of bacterial infection had low sensitivity (10-50%) and high specificity (90-100%), whereas the clinical diagnostic model provided a broad range of values for sensitivity and specificity. Conclusions Emergency department physicians tend to underestimate the likelihood of serious bacterial infection in young children with fever, leading to undertreatment with antibiotics. A clinical diagnostic model could improve decision making by increasing sensitivity for detecting serious bacterial infection, thereby improving early treatment.

Comparative Accuracy of Renal Duplex Sonographic Parameters in the Diagnosis of Renal Artery Stenosis: Paired and Unpaired Analysis

OBJECTIVE The purpose of this study was to evaluate the test performance of duplex sonographic parameters in screening for hemodynamically significant renal artery stenosis, which occurs in approximately 5% of persons with hypertension. MATERIALS AND METHODS A comprehensive literature search was conducted to find studies on the diagnosis of renal artery stenosis in which duplex sonography and intraarterial angiography were compared and in which sensitivity and specificity were calculated. MEDLINE (1966-2005), EMBASE (1988-2005), and reference lists were searched and the authors contacted. Data were subjected to meta-analysis according to the hierarchical summary receiver operating characteristic curve model. Heterogeneity in test performance relating to population and design features was investigated. RESULTS From 1,357 titles, 88 studies involving 9,974 arteries in 8,147 patients were included. The following four parameters were evaluated: peak systolic velocity (21 studies), acceleration time (13 studies), acceleration index (13 studies), and renal-aortic ratio (13 studies). The corresponding diagnostic odds ratios (ORs) were 60.9 (95% CI, 28.3-131.2), 28.9 (95% CI, 7.1-117.2), 16.0 (95% CI, 5.1-50.6), and 29.3 (95% CI, 12.7-67.7). Results based on studies in which parameters were directly compared showed that peak systolic velocity had greater accuracy than renal-aortic ratio (relative diagnostic OR, 1.8; p = 0.03; nine studies) and acceleration index (relative diagnostic OR, 5.3; p < 0.001; five studies). Acceleration time versus acceleration index showed no evidence of a difference in accuracy (relative diagnostic OR, 1.1; p = 0.65; nine studies). Analysis of peak systolic velocity used in combination with other parameters compared with peak systolic velocity alone (seven studies) showed evidence of a shift in test positivity (p < 0.001) but only weak evidence of improvement in accuracy (relative diagnostic OR, 1.6; p = 0.09). CONCLUSION Sonography is a moderately accurate screening test for renal artery stenosis. The single measurement, peak systolic velocity, has the highest performance characteristics, an expected sensitivity of 85% and specificity of 92%. Additional measurements do not increase accuracy.

Absolute and relative accuracy of rapid urine tests for urinary tract infection in children: a meta-analysis

Rapid urine tests, such as microscopy, for bacteria and white cells, and dipsticks, for leucocyte esterase and nitrites, are often used in children that are unwell to guide early diagnosis and treatment of urinary tract infection. We aimed to establish whether these tests were sufficiently sensitive to avoid urine culture in children with negative results and to compare the accuracy of dipsticks with microscopy. Medline, Embase, and reference lists were searched. Studies were included if urine culture results were compared with rapid tests in children. Data were analysed to obtain absolute and relative accuracy estimates. Data from 95 studies in 95 703 children were analysed. Summary estimates for sensitivity and specificity for microscopy for Gram-stained bacteria were 91% (95% CI 80-96) and 96% (92-98), for unstained bacteria were 88% (75-94) and 92% (84-96), for urine white cells were 74% (67-80) and 86% (82-90), for leucocyte esterase or nitrite positive dipstick were 88% (82-91) and 79% (69-87), and for nitrite-only positive dipstick were 49% (41-57) and 98% (96-99). Microscopy for bacteria with Gram stain had higher accuracy than other laboratory tests with relative diagnostic odds ratio compared with bacteria without Gram stain of 8.7 (95% CI 1.8-41.1), white cells of 14.5 (4.7-44.4), and nitrite of 22.0 (0.7-746.3). Microscopy for white cells should not be used for the diagnosis of urinary tract infection because its accuracy is no better than that of dipstick, laboratory facilities are needed, and results are delayed. Rapid tests are negative in around 10% of children with a urinary tract infection and cannot replace urine culture. If resources allow, microscopy with Gram stain should be the single rapid test used.

Prevention of recurrent urinary tract infection in children.

Purpose of review Urinary tract infection (UTI) in children is common (5–10%) and recurs in 10–30%. UTI causes an unpleasant, usually febrile illness in children. This review focuses on studies evaluating interventions to prevent UTI in children and published between January 2007 and June 2008. Recent findings Three relevant updated Cochrane reviews, six randomized trials and an evidence-based guideline were published in the study period. Five of the six trials and one of the three Cochrane updates included data on the effects of relevant interventions in children. Three of the six trials investigated the efficacy of long-term, low-dose antibiotics as prophylaxis, and the other trials and both Cochrane updates evaluated complementary therapies such as vitamin A, probiotics and herbal supplements. Summary The benefit of prophylactic antibiotics for the prevention of recurrent UTI in children remains unclear because of underpowered and suboptimally designed trials, but these studies suggest that any benefit is likely to be small, and clinical significance may be limited. The trials of complementary interventions (vitamin A, probiotics, cranberry, nasturtium and horseradish) generally gave favourable results but were not conclusive. Children and families who use these products should be aware that further infections are possible despite their use.

Denominators Do Matter: It's a Myth—Urinary Tract Infection Does Not Cause Chronic Kidney Disease

Pediatric practice is not different from other medical specialties: it is full of beliefs—some true and some false, some harmful and some not. Generations of budding pediatricians have been educated about the perils of urinary tract infection (UTI) in children. Since the 1950s we have been taught that UTI is not like other acute infectious illnesses that affect children,1 and we have also propagated the belief that the clinical importance of UTI was not primarily about timely diagnosis and acute care of what is usually an unpleasant, febrile illness but, rather, about the risk of chronic kidney disease (CKD), hypertension, and ultimately end-stage kidney disease.2 Looking back, the numerical disconnect between the dozens, even hundreds of children with UTI that we treated acutely and followed up and the extreme rarity of end-stage kidney disease caused by so-called reflux nephropathy was obvious but not recognized. Perhaps it is because we managed the children with UTI and adult nephrologists managed the adults in their 30s to 50s with the “resulting” end-stage kidney disease. Or, maybe we were focused on the care of individual children and did not consider the critical importance of denominators in … Address correspondence to Gabrielle J. Williams, BSc, MPH, PhD, Centre for Kidney Research, Childrens Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia. E-mail: gabriew4{at}chw.edu.au

Variability and accuracy in interpretation of consolidation on chest radiography for diagnosing pneumonia in children under 5 years of age

Consolidation on chest radiography is widely used as the reference standard for defining pneumonia and variability in interpretation is well known but not well explored or explained.

Accuracy of the “traffic light” clinical decision rule for serious bacterial infections in young children with fever: a retrospective cohort study

Objectives To determine the accuracy of a clinical decision rule (the traffic light system developed by the National Institute for Health and Clinical Excellence (NICE)) for detecting three common serious bacterial infections (urinary tract infection, pneumonia, and bacteraemia) in young febrile children. Design Retrospective analysis of data from a two year prospective cohort study Setting A paediatric emergency department. Participants 15 781 cases of children under 5 years of age presenting with a febrile illness. Main outcome measures Clinical features were used to categorise each febrile episodes as low, intermediate, or high probability of serious bacterial infection (green, amber, and red zones of the traffic light system); these results were checked (using standard radiological and microbiological tests) for each of the infections of interest and for any serious bacterial infection. Results After combination of the intermediate and high risk categories, the NICE traffic light system had a test sensitivity of 85.8% (95% confidence interval 83.6% to 87.7%) and specificity of 28.5% (27.8% to 29.3%) for the detection of any serious bacterial infection. Of the 1140 cases of serious bacterial infection, 157 (13.8%) were test negative (in the green zone), and, of these, 108 (68.8%) were urinary tract infections. Adding urine analysis (leucocyte esterase or nitrite positive), reported in 3653 (23.1%) episodes, to the traffic light system improved the test performance: sensitivity 92.1% (89.3% to 94.1%), specificity 22.3% (20.9% to 23.8%), and relative positive likelihood ratio 1.10 (1.06 to 1.14). Conclusion The NICE traffic light system failed to identify a substantial proportion of serious bacterial infections, particularly urinary tract infections. The addition of urine analysis significantly improved test sensitivity, making the traffic light system a more useful triage tool for the detection of serious bacterial infections in young febrile children.

Cranberry Products and Prevention of Urinary Tract Infections

CLINICAL QUESTION Are cranberry products (juice, tablets, capsules, and syrup) associated with prevention of urinary tract infections (UTIs) compared with placebo or other treatments? BOTTOM LINE Cranberry products are not associated with prevention of UTIs. However, lack of association of cranberry products with a reduced incidence of UTIs in clinical trials may be due to lack of participant adherence, lack of sufficient active ingredient in the cranberry product, or lack of sufficient statistical power.

Diagnosis and management of urinary tract infection in children

A young child presents to their primary health provider with fever and irritability. How likely is a urinary tract infection? How should a urine sample be collected? How accurate are urinary dipsticks and microscopy compared with culture for the diagnosis? What route and type of antibiotics should be used? What imaging is indicated? Diagnosing and treating children with urinary tract infection presents many questions. This review summarises the most relevant recent primary studies, systematic reviews and guidelines.