A Simple Method for Selecting Urine Samples that Need Culturing

Prevalence of Urinary Tract Infection and Vesicoureteral Reflux in Children with Lower Urinary Tract Dysfunction

Introduction/Objective. Urinary tract infections (UTIs) in children represent a significant public health problem due to their high prevalence and the need for timely diagnosis and adequate treatment. Automated methods using fluorescent flow cytometry are increasingly being used in laboratories for the screening of UTIs. The aim of this study was to determine the cut-off values for leukocyturia and bacteriuria using fluorescent flow cytometry for the screening of urinary tract infections in the pediatric population. Methods. A total of 821 urine samples were cultured, of which 366 samples met the criteria for fluorescent flow cytometry on the automated Sysmex UF-4,000 analyzer. The number of leukocytes and bacteria was compared with the culture results. Results. Of the total urine cultures tested, 209 (25.5%) were positive, and 599 (73%) were negative. There was a statistically significant difference in the prevalence of uropathogens according to the age of the children (p < 0.001). The area under the curve (AUC) for leukocyte count was 0.77 (95% CI: 0.71-0.84), while the AUC for bacterial count was 0.85 (95% CI: 0.81-0.89). A low negative likelihood ratio (0) was observed at the cut-off for bacteria of 40.1, and the negative predictive value was high (between 91% and 99%). Conclusion. Determination of leukocyte and bacterial counts in urine in children using fluorescent flow cytometry can serve as an initial test when deciding on urine culture in microbiological laboratories. These results may indicate the necessity of reducing unnecessary urine cultures while providing faster confirmation of negative test results.

Early antibiotic treatment for urinary tract infection (UTI) in young children can prevent renal scarring. Sensitivity of pyuria and positive urine nitrite test as indicators of UTI are low, whereas results of urine culture, the gold standard for diagnosing UTI, may not be available for 48--72 h. Novel markers for rapid and accurate diagnosis of UTI would help in the early initiation of treatment in children with suspected UTI. We studied the utility of urinary neutrophil gelatinase-associated lipocalin (NGAL) as an early marker of UTI. This study included 100 children between 3 months and 5 years with suspected UTI. After parental consent, a midstream clean catch or suprapubic aspirate urine specimen was sent for culture and NGAL analysis. Sensitivity and specificity of urine NGAL as a marker of UTI were estimated. Of the 100 children evaluated, urine culture was positive in 34%. Median urine NGAL values were higher in culture-positive children than in culture-negative children (223.20 vs 13.65, P = 0.0001). Receiver operating curve analysis showed an optimal cutoff level of 27 ng/ml for urine NGAL (odds ratio, 8.2, 95% confidence interval, 3.1--22.1) correlating best with culture positivity. Sensitivity and specificity of urine NGAL estimation were significantly better (79.4% and 68.2%) when compared with urine white blood cell estimation (70.6% and 53%). Urine NGAL is a sensitive and specific marker to predict UTI in children with a cutoff level of 27 ng/ml. It may serve as a screening test for detecting simple, uncomplicated UTI in young children.

To determine the validity of the Uriscreen, a rapid diagnostic test based on the detection of urine catalase for the early detection of urinary tract infection (UTI) in children, compared with standard urinalysis and dipstick tests. STUDY DESIGN. Cross-sectional study. Children 1 month to 17 years of age who presented to the emergency department of a pediatric tertiary care center between March and November of 1996 with symptoms suggestive of UTI. Urine specimens obtained from a random sample of 121 patients were evaluated simultaneously for possible UTI by Uriscreen (catalase test), urinalysis (microscopic pyuria), dipstick (leukocyte esterase and nitrite), and quantitative urine culture. All specimens were collected by one of three sterile techniques (midstream void technique, bladder catheterization, or suprapubic aspiration), as appropriate for age, and tested immediately. Using the quantitative urine culture as the gold standard (reference test), the sensitivity, specificity, and positive and negative predictive values of all the screening tests were determined and compared. Age, sex, temperature, presenting symptoms, and method of urine collection were recorded for each participant. Of the 121 patients, 35 (28.9%) had positive culture results: 30 girls (85.7%) and 5 boys (14.3%). Compared with urinalysis and dipstick tests, Uriscreen had the highest sensitivity (100% vs 88.6% and 97.1%, respectively) and the highest negative predictive value (100% vs 95% and 98.6%, respectively), but the poorest specificity (68.6% vs 88.4% and 82.5%, respectively) and positive predictive value (56.4% vs 75.6% and 69.4%, respectively). The clinical use of Uriscreen for the presumptive diagnosis of UTI in children is limited and not significantly superior to urinalysis or the dipstick test. However, because of its 100% sensitivity and negative predictive value and its ease of use, rapidity, and low cost, it is recommended highly for ruling out the diagnosis of UTI. In laboratories, a negative Uriscreen result may prevent the need for performing expensive urine cultures.

BACKGROUND AND OBJECTIVES:Febrile urinary tract infections and pyelonephritis are common in children and frequently lead to hospitalization for management, especially in the child who appears toxic. The American Academy of Pediatrics (AAP) practice parameter on the diagnosis, treatment and evaluation of the initial urinary tract infection in febrile infants and young children provides experience and evidence-based guidelines for the practitioner caring for children between the ages of 2 months to 2 years. No established guideline exists for older children and the AAP guideline does not specifically focus on inpatient care.METHODS:We conducted a comprehensive review of recently published literature and practice guidelines to develop a consensus on the inpatient diagnosis and management of children with pyelonephritis.RESULTS:Eight recommendations are proposed for the diagnosis and management, including revised guidelines for the imaging studies postpyelonephritis on the basis of current best evidence.CONCLUSION:Proper diagnosis of pyelonephritis, timely initiation of appropriate therapy and identification of children at risk for renal injury will help to reduce immediate as well as long-term complications due to chronic kidney disease.

Management of Functional Constipation in Children with Lower Urinary Tract Symptoms: Report from the Standardization Committee of the International Children's Continence Society

Purpose: Fever serves as the most frequent cause of visits to emergency/outpatient pediatric departments among children under the age of five. Very frequently, the youngster is given antibiotics on an arbitrary basis without receiving the proper examination for a urinary tract infection (UTI). This study’s goals were to assess the prevalence of UTIs in febrile children between 6 months and 5 years of age. To study the proportion of UTIs in children between 6 months and 5 years presenting with fever. To study the association of various risk factors with UTI. Methodology: This Cross-sectional Descriptive observational research was done in the Pediatric department of tertiary care hospital from August 2020 to December 2022, in febrile kids between 6 months and 5 years age group using different variables. Association between two qualitative variables was seen by using Chi-square/Fischer’s exact test. A P < 0.05 was considered statistically significant whereas a P < 0.001 was considered highly significant. Results: Among the total study population, it was found that 5.58% of the patients with fever without focus had a UTI, while the majority of patients, 94.42% did not have a UTI but had fever without a specific focus. In UTI cases, urine culture growth patterns showed the presence of different isolates, including Escherichia coli (30.43%), Klebsiella (56.52%), Pseudomonas aeruginosa (8.7%), and Candida (4.34%). Conclusion: In the present research, the overall occurrence of UTI in children <5 years with fever without focus was 5.58%. Patients with significant pyuria and positive urine culture (UTI) were 43.75% and with significant pyuria but the sterile culture was 56.25%. So, it is concluded that significant pyuria can be sterile pyuria and cannot be labeled as UTI without confirmation on the urine culture report.

Distinguishing between urinary tract infection (UTI) and colonization (UTC) in patients with neurogenic bladders who require clean intermittent catheterization (CIC) is difficult. Urinary neutrophil gelatinase-associated lipocalin concentrations (uNGAL) are increased in UTIs. Our objective was to determine the predictive accuracy of uNGAL for UTI in CIC-dependent children. Cross-sectional study of CIC-dependent patients from August, 2015 to November, 2016. UTI was defined as (1) growth of ≥ 50,000cfu/mL of a uropathogen, (2) > 10 urinary white blood cells/hpf, and (3) ≥ 2 of the following: temperature > 38°C, abdominal pain, back pain, worsened incontinence, pain with catheterization, or malodorous/cloudy urine. Positive urine cultures that did not meet these criteria were grouped as UTC, and negative cultures were grouped as no growth. Two hundred one patients were included (no growth = 100, UTC = 77, UTI = 24). Median (interquartile range) uNGAL was higher in the UTI group (UTI 1361 (931, 2516)μg/g creatinine, UTC 246 (106, 548)μg/g creatinine, no growth 36 (11, 179)μg/g creatinine, p < 0.01 for all comparisons). The area under the ROC curve for uNGAL for UTI versus no UTI was 0.89, 95% CI (0.80-0.98). uNGAL is elevated in CIC-dependent children with UTI compared to those with negative cultures and those with UTC.

Background: Urinary tract infection (UTI) is a term applied to a variety of clinical conditions ranging from asymptomatic presence of bacteria in the urine to severe infection of the kidney with resultant sepsis. According to The National Institute for Health and Clinical Excellence (NICE) guidelines, urinary tract infection is defined by a combination of clinical features and the presence of bacteria in urine. The risk factors of UTI are age, gender, constipation, lack of circumcision, not taking anthelmintic and lack of toilet training. Methods: This was across sectional study conducted on febrile preschool children, aged 3 to 6 years, who attended the outpatient department of Sri Siddhartha Medical College, Tumkur. Children with symptoms suggestive of UTI were enrolled, and a written informed consent was obtained from the parents. They were then interviewed using structured questionnaire for UTI. Results: Out of 194 febrile preschool children, 21 cases were diagnosed to have UTI. Of the 194 cases, 102 (52.6%) were females and 92 (47.42%) were male. Out of 21 urine culture positive cases 14 (66.6%) were females and 7 (33.33%) were males. Occurrence of UTI was 7.6% in febrile males, 13.72% in febrile females and had the estimated overall occurrence is 10.8%. Fever was present in all the cases. Besides fever, 47.62% children had increased frequency, 42.86% had excessive crying while micturition and 38.10% had chills and rigors. Foul smelling urine was present in 33.33% of children while 23.81% had abdominal pain. Out of 92 male children studied 16 (17.39%) males had phimosis, of which 2 (12.5%) developed urinary tract infections. Constipation was seen in 3 (14.29%) children with UTI. Worm infestation was seen in 5 (23.81%) children with UTI. Conclusions: Children with urinary tract infections usually present with nonspecific symptoms and signs and hence a urine analysis and culture should always be part of an initial diagnostic evaluation of urinary tract infections. Female sex, constipation, not taking anthelmintic, lack of toilet training and phimosis are significant risk factors for febrile urinary tract infection in children.

ObjectivePrevious studies on diagnostic accuracy of dipstick testing for leukocyte esterase (LE) and nitrite to diagnose urinary tract infection (UTI) had used urine culture, which is an imperfect gold standard. Estimates of diagnostic accuracy obtained using the classical gold standard framework might not reflect the true diagnostic accuracy of dipstick tests.MethodsWe used the dataset from a prospective, observational study conducted in the emergency department of a teaching hospital in southern India. Patients with a clinical suspicion of UTI underwent dipstick testing for LE and nitrite, urine microscopy, and urine culture. Based on the results of urine microscopy and culture, UTI was classified into definite, probable, and possible. Patients with microscopic pyuria and a positive urine culture were adjudicated as definite UTI. Unequivocal imaging evidence of emphysematous pyelonephritis or perinephric collections was also considered definite UTI. We estimated the diagnostic accuracy of LE and nitrite tests using the classical analysis (assuming definite UTI as gold standard) and two different Bayesian latent class models (LCMs; 3-tests in 1-population and 2-tests in 2-populations models).ResultsWe studied 149 patients. Overall, 64 (43%) patients had definite, 76 (51%) had probable, and 2 (1.3%) had possible UTI; 7 (4.6%) had alternate diagnoses. In classical analysis, LE was more sensitive than nitrite (87.5% versus 70.5%), while nitrite was more specific (24% versus 58%). The 3-tests in 1-population Bayesian LCM indicated a substantially better sensitivity and specificity for LE (98.1% and 47.6%) and nitrite (88.2% and 97.7%). True sensitivity and specificity of urine culture as estimated by the model was 48.7% and 73.0%. Estimates of the 2-tests in 2-populations model were in agreement with the 3-tests in 1-population model.ConclusionsBayesian LCMs indicate a clinically important improvement in the true diagnostic accuracy of urine dipstick testing for LE and nitrite. Given this, a negative dipstick LE would rule-out UTI, while a positive dipstick nitrite would rule-in UTI in our study setting. True diagnostic accuracy of urine dipstick testing for UTI in various practice settings needs reevaluation using Bayesian LCMs.

Purpose: To review the changing paradigms in the diagnosis, investigation and management of Urinary Tract Infections (UTIs) in children beyond the neonatal period. Methods: A literature search was done using PUBMED, EBSCO host database and GOOGLE SCHOLAR of all articles including reviews and guidelines on UTIs in children for the last ten years. A total of 2725 articles including review articles and guidelines published over the last 10 years were searched and reviewed. Results: UTIs are the second most common cause of serious bacterial infections in early childhood, thus placing a huge financial burden on the health budget. Despite increasing resistance to several first-line antibiotics, appropriate antibiotic treatment has almost eliminated mortality. Early guidelines advocated aggressive treatment and extensive imaging studies, particularly for the detection of serious ureteric reflex and kidney scarring. Treatment in the acute episode is aimed at eradication of bacteriuria and alleviation of symptoms. Long-term goals include prevention of recurrent attacks of UTIs, kidney scarring and correction of urological lesions that may predispose to recurrent infections. Although there is increasing evidence to show that long-term antimicrobial prophylaxis may be associated with a reduced risk of recurrent infection in selected groups of patients, but not renal scarring, more studies are needed to confirm this. Surgical intervention is now restricted to cases with severe vesicoureteric reflux and failed medical management with endoscopic surgery being increasingly used in most centres compared to open surgery. Conclusion: Following extensive research, a more tangible approach to UTIs is advocated providing for more judicious use of resources with reduced harm from procedures, without affecting outcome. This review addresses the diagnosis, management and treatment of UTIs in children beyond the neonatal period.

Urinary Tract Infection in Children

Background: Urinary tract infection (UTI) is one of the most frequent bacterial causes of fever in children and often remains underdiagnosed due to its nonspecific presentation. Early recognition is critical, as delayed diagnosis can lead to complications such as renal scarring, hypertension, or sepsis. Identifying the frequency of UTI among febrile children, especially those without localized symptoms, is essential to enhance clinical vigilance and improve diagnostic accuracy. Objective: To evaluate the frequency of urinary tract infections in children presenting with fever and identify associated clinical risk factors. Methods: This cross-sectional study was conducted at the Department of Pediatrics, Hayatabad Medical Complex, Peshawar. A total of 202 children aged 0–5 years presenting with fever &gt;100.4°F (38°C) of less than 7 days’ duration were enrolled using consecutive non-probability sampling. Children with prior UTIs, recent antibiotic use, congenital urinary anomalies, or requiring hospitalization were excluded. Clean-catch midstream or catheterized urine samples were collected under aseptic conditions. Initial screening was performed using dipstick testing for leukocyte esterase and nitrite, followed by confirmation via urine culture, where ≥10⁵ CFU/mL of a single uropathogen was considered diagnostic. Data were analyzed using SPSS version 25, with significance set at p&lt;0.05. Results: Of the 202 children enrolled, 92 (45.5%) were male and 110 (54.5%) female, with a mean age of 2.91 ± 1.40 years. UTI was confirmed in 29 children (14.4%). Among UTI-positive cases, 19 (65.5%) were aged 1–3 years, and 23 (79.3%) had a fever duration of more than 24 hours. Dysuria was reported in 14 (48.3%) cases, while frequent urination was present in 8 (27.6%). Conclusion: UTI was identified in a considerable proportion of febrile children, particularly among those with prolonged fever exceeding 24 hours. These findings advocate for routine urine evaluation in febrile pediatric cases lacking a clear source.

BackgroundDiagnosing urinary tract infections (UTIs) in children in the emergency department (ED) is challenging due to the variable clinical presentations and difficulties in obtaining a urine sample free from contamination. Clinicians need to weigh a range of observations to make timely diagnostic and management decisions, a difficult task to achieve without support due to the complex interactions among relevant factors. Directed acyclic graphs (DAG) and causal Bayesian networks (BN) offer a way to explicitly outline the underlying disease, contamination and diagnostic processes, and to further make quantitative inference on the event of interest thus serving as a tool for decision support.MethodsWe prospectively collected data on children present to ED with suspected UTIs. Through knowledge elicitation workshops and one-on-one meetings, a DAG was co-developed with clinical domain experts (the Expert DAG) to describe the causal relationships among variables relevant to paediatric UTIs. The Expert DAG was combined with prospective data and further domain knowledge to inform the development of an application-oriented BN (the Applied BN), designed to support the diagnosis of UTI. We assessed the performance of the Applied BN using quantitative and qualitative methods.ResultsWe summarised patient background, clinical and laboratory characteristics of 431 episodes of suspected UTIs enrolled from May 2019 to November 2020. The Expert DAG was presented with a narrative description, elucidating how infection, specimen contamination and management pathways causally interact to form the complex picture of paediatric UTIs. Parameterised using prospective data and expert-elicited parameters, the Applied BN achieved an excellent and stable performance in predicting Escherichia coli culture results, with a mean area under the receiver operating characteristic curve of 0.86 and a mean log loss of 0.48 based on 10-fold cross-validation. The BN predictions were reviewed via a validation workshop, and we illustrate how they can be presented for decision support using three hypothetical clinical scenarios.ConclusionCausal BNs created from both expert knowledge and data can integrate case-specific information to provide individual decision support during the diagnosis of paediatric UTIs in ED. The model aids the interpretation of culture results and the diagnosis of UTIs, promising the prospect of improved patient care and judicious use of antibiotics.

Background: The increased prevalence of infection in nephrotic syndrome is due to immunoglobulin loss, defective T cell function, and presence of ascites, relative malnutrition, and immunosuppressive therapy and associated with other factors. The objective of this study was to study the incidence, aetiology and the antibiotic sensitivity pattern of urinary tract infections (UTI) in children at presentation of nephrotic syndrome (NS).Methods: A retrospective hospital-based study carried out in IMS and SUM Hospital, Bhubaneswar, India. Seventy six children aged between two to twelve years with a diagnosis of NS at the time of were studied from April 2014 to March 2016.Results: The mean age of males was 5.9±0.5years and females are 6.2±0.8years. Pyuria was noted in 44 (57.89%) of the patients. Boys were more commonly affected with urinary tract infection than girls with a ratio of 1.9:1. UTI is the most common encountered infection and was predominantly caused by E. Coli in 18 (39%), Klebsiella species 7 (15.21%) and culture negative in 8 (17.28%) cases. There was high in vitro resistance of these organisms to cefixime and ampicillin but sensitive to cefotaxime, amikacin, ceftriazone , piperacillin- tazobactum and vancomycin.Conclusions: It is recommended that UTI should be sought for in patients with nephrotic syndrome and treatment should be prompt and appropriate taking into account of etiology and predisposing factors. UTI is one of the most common infections accompanying NS due to many factors. A high index of suspicion and early institution of appropriate antibiotics will help in reducing morbidity and mortality.