Evidence behind the WHO guidelines: Hospital Care for Children: what are appropriate methods of urine collection in UTI?

Improving clean-catch contamination rates: A prospective interventional cohort study

OBJECTIVES

The clean-catch method of urine collection carries a high contamination rate. This study aims to evaluate the effects on contamination rate of providing a parent handout and pre-made urine collection pack for clean-catch urine collection.

METHODS

We conducted a single-centre prospective cohort interventional study in a tertiary paediatric ED. All children younger than 24 months who presented from April 2013 to June 2014 requiring a urine sample to be obtained were included. The intervention was provision of a pre-made urine collection pack including a standardised information handout. The primary outcome measure was the difference in proportion of urine contamination in samples obtained via a clean-catch pre- and post-intervention.

RESULTS

The total number of urine specimens included was 288 in the pre-intervention group and 333 in the post-intervention group. Contamination rates were 14.9% in the pre-intervention group and 11.4% in the post-intervention group. There was no statistically significant reduction in contamination (P = 0.19). The contamination rates appeared to be associated with gender, with (pooled) female contamination rates being 16.4% (44/269) and male contamination rates being 10.5% (37/352). Most specimens of urine were collected via the clean-catch method (81.2%), followed by catheter urine specimen (13.7%) and suprapubic aspirate (5.1%). The contamination rate in our study for clean-catch urine collectively was 13%, catheter urine specimen 3.8% and suprapubic aspirate 0%.

CONCLUSION

The contamination rate of clean-catch urine did not improve with the implementation of a pre-made urine collection pack including standardised written instructions.

Urinary tract infection in infants: the significance of low bacterial count

BACKGROUND

In national guidelines for urinary tract infection (UTI) in children, different cut-off levels for defining bacteriuria are used. In this study, the relationship between bacterial count in infant UTI and inflammatory parameters, frequency of vesicoureteral reflux (VUR), kidney damage, and recurrent UTI was analyzed.

METHODS

We conducted a population-based retrospective study of 430 infants age <1 year with symptomatic UTI diagnosed by suprapubic aspiration. Clinical and laboratory parameters, findings on voiding cystourethrography and (99m)technetium dimercapto-succinic acid scintigraphy, and frequency of recurrence were related to bacterial count at the index UTI.

RESULTS

Eighty-three (19%) infants had bacterial counts <100,000 colony-forming units (CFU)/ml and 347 (81%) had ≥100,000 CFU/ml. There was similar frequency of VUR (19% in both groups), kidney damage (17 and 23%, p = 0.33) and recurrent UTI (6 and 12%, p = 0.17) in the low and high bacterial group. Non-E. coli species were more prevalent (19 versus 6%, p = 0.0006) and mean C-reactive protein was lower (50 vs. 79 mg/l, p <0.0001) in the low bacteria group.

CONCLUSIONS

UTI with low bacterial count is common and of importance since it may be associated with VUR and renal damage. Non-E. coli species and low inflammatory response were more prevalent in UTI with low bacterial count.

A prospective comparative pilot study comparing the urine collection pad with clean catch urine technique in non-toilet-trained children

INTRODUCTION

There are many different methods for collecting urine from paediatric patients in emergency departments. Therefore, the aims of the study were to:

METHODS

The three month study was a prospective non-randomised comparative paediatric pilot study. A purposeful sample of children, requiring a urine microscopy for clinical management, presenting to one district emergency department was enrolled in the study to compare two non-invasive techniques of urine collection.

RESULTS

Thirty-three patients were enrolled and satisfactory samples were obtained from 22 patients. The heavy (mixed growth) contamination rate in the UCP group (n=2; 9.1%) versus the CCU group (n=1; 4.5%) was not statistically significant (p=0.50 by Fisher's exact test). The rate of agreement (n=20; 91%) in diagnosing or excluding urinary tract infection between the two groups was high. The median time to urine collection between the two groups (UCP method 30 min; CCU 107.5 min) was statistically significant (p<0.002, Mann-Whitney U test).

CONCLUSIONS

This study suggests that UCPs are practicable in Australasian Emergency Departments and may lead to faster diagnosis, disposition and reduced hospital stay.

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.

Diagnosis of urinary tract infections in children

PURPOSE OF REVIEW

Urinary tract infections remain a significant cause of serious bacterial infections in children and can result in chronic kidney disease. Thus, prompt diagnosis and initiation of treatment of urinary tract infections are paramount objectives.

RECENT FINDINGS

A number of advances in technology have allowed expeditious examination of the urine. Recent meta-analyses evaluated the ability of these tests to determine the presence or absence of urinary tract infection in children. In addition, understanding the prevalence of urinary tract infection in various populations will help guide the clinician to the appropriate level of suspicion and the appropriate work-up for urinary tract infection.

SUMMARY

Although culture of the urine remains the gold standard for diagnosing and treating urinary tract infections, technical considerations including method of collection of the urine as well as the time necessary for culture results remain problematic. More rapid techniques include dipstick analyses for the presence of leukocyte esterase or nitrites, microscopic analysis for white blood cells or bacteria, and automated urine cell analyzer to determine bacterial and white blood cell counts in the urine. Recent results indicate it is possible to limit the number of urine cultures performed by eliminating those that have a low probability of being positive. In addition, recent studies reexamining the prevalence of urinary tract infections in various populations indicate that diagnostic testing can be aimed at those patients who are in the higher-risk groups.