Update on Childhood Urinary Tract Infection and Vesicoureteral Reflux
Section snippets
Pathogenesis
Urinary infection usually is ascending, with inoculation of fecally derived organisms from the urethra and peri-urethral tissues into the bladder.4 The most prevalent pathogens in several recent pediatric studies were Escherichia coli (54%-67%), Klebsiella (6%-17%), Proteus (5%-12%), Enterococcus (3%-9%) and Pseudomonas (2%-6%).5, 6, 7 Previously, E coli accounted for 80% to 90% of infections, and it is not clear if the change in frequency was caused by sampling bias (not all infections
Clinical Presentation
Young infants often present with fever alone (≥38°C); irritability, vomiting, lethargy, or poor feeding variably may be present. For those younger than 3 months there is an increased risk of bacteremia and a greater possibility of undiagnosed congenital urologic malformations.15 Older children generally have more explicit symptoms of bladder inflammation and/or flank pain. A recent meta-analysis evaluated the diagnostic accuracy of UTI signs and symptoms in infants (3-24 mo) with fever (≥38°C),
Specimen Collection
A noncontaminated urine sample is fundamental. For infants and non–toilet-trained children, the most accurate method of collection is suprapubic bladder aspiration, however, it rarely is practical. Urethral catheterization or spontaneously voided clean midstream samples (usually obtained while disinfecting for catheterization or suprapubic bladder aspiration) are the most reliable alternatives. Perineal urine bag collection has a high rate of contamination and should be avoided for culture, but
Infants Younger Than 3 Months
All febrile neonates should be treated with intravenous antibiotics pending urine, blood, and cerebrospinal fluid culture results. For infants older than 1 month but younger than 3 months of age with suspected or confirmed UTI, intravenous antibiotics are recommended after appropriate cultures (blood, urine, ± cerebrospinal fluid). There have been no large prospective studies of outpatient management in this age group.27
Pyelonephritis: Infants Older Than 3 Months and Children
A 2007 Cochrane Review concluded that 10 to 14 days of oral treatment with
UTI Recurrence
Recurrent UTIs develop in approximately 75% of children whose first infection occurs before the age of 1 year, and in about 40% of girls and 30% of boys presenting after this age.37 Most studies of features predicting recurrence have important limitations.37 Risk factors identified include dilating VUR, family history of UTI, infrequent voiding, and inadequate fluid ingestion. Strategies that may help prevent recurrence include management of voiding dysfunction and increased fluid intake. The
Long-Term Outcome
Approximately 70% of infants and children with their first febrile UTI have pyelonephritis39, 40 and renal scars may follow in 15% to 30%.33, 41 With timely appropriate therapy most infants and children recover promptly without major long-term sequelae, but a small number are at risk for significant morbidity, progressive renal damage, and renal insufficiency. Included are those with urologic abnormalities, dysplasia, and recurrent pyelonephritis.37
Covert Bactiuria
Covert bactiuria (asymptomatic colonization of the urinary tract) is often an incidental finding during screening or follow-up evaluation after treatment of symptomatic UTI. If it is ascertained that the infant or child is truly symptom free, has a normal physical examination, normal voiding pattern, no impairment of renal function, and no anomalies on renal imaging, antibiotic therapy should be avoided.32 E coli strains causing asymptomatic bactiuria have evolved to persist for months to years
VUR and Reflux Nephropathy
VUR is a frequent pediatric urologic disorder affecting 1% to 2% of otherwise normal children.42 VUR is believed to predispose to UTI, and the two are linked with renal scarring. In 1960, Hodson and Edwards43 associated VUR with chronic pyelonephritis, which subsequently came to be known as reflux nephropathy.44 After acute pyelonephritis, renal scarring visible on intravenous urography takes about 1 to 2 years to develop, but is seen much earlier on DMSA.45, 46 The International Reflux Study
Conclusions
The recent knowledge about UTI and VUR, and controversies regarding the extent of their role in renal scarring, has generated much interest among clinicians as well as researchers. The consequences of delayed versus early treatment of acute febrile UTI and the appropriateness of medical versus surgical versus no intervention for various grades of VUR will continue to be debated until more prospective, randomized, and preferably blinded and placebo-controlled studies are performed to confirm or
References (97)
- et al.
Infant vesicoureteral reflux: a comparison between patients presenting with a prenatal diagnosis and those presenting with a urinary tract infection
Urology
(2003) - et al.
Incidence and severity of vesicoureteral reflux in children related to age, gender, race and diagnosis
J Urol
(2003) - et al.
Antibiotic resistance in outpatient urinary isolates: final results from the North American Urinary Tract Infection Collaborative Alliance (NAUTICA)
Int J Antimicrob Agents
(2005) Microbial virulence determinants and the pathogenesis of urinary tract infection
Infect Dis Clin North Am
(2003)- et al.
Origins and virulence mechanisms of uropathogenic Escherichia coli
Exp Mol Pathol
(2008) - et al.
Minireview: functions of the renal tract epithelium in coordinating the innate immune response to infection
Kidney Int
(2004) - et al.
A head-to-head comparison: “clean-void” bag versus catheter urinalysis in the diagnosis of urinary tract infection in young children
J Pediatrics
(2005) Evolving concepts in the evaluation of the child with a urinary tract infection
J Pediatrics
(1994)- et al.
Pyuria and bacteriuria in urine specimens obtained by catheter from young children with fever
J Pediatrics
(1994) The evolving approach to the young child who has fever and no obvious source
Emerg Med Clin North Am
(2007)
Cortical scintigraphy in the evaluation of renal parenchymal changes in children with pyelonephritis
J Pediatr
Chronic pyelonephritis and vesico-ureteric reflex
Clin Radiol
Implications of certain genetic polymorphisms in scarring in vesicoureteric reflux: importance of ACE polymorphism
Am J Kidney Dis
Congenitally small kidneys with reflux as a common cause of nephropathy in boys
Kidney Int
The long-term results of prospective sibling reflux screening
J Urol
The relationship among dysfunctional elimination syndromes, primary vesicoureteral reflux and urinary tract infections in children
J Urol
Relationship between dysfunctional voiding and reflux
J Urol
Vesicoureteral reflux and voiding dysfunction: a prospective study
J Urol
Historical clues to the complex of dysfunctional voiding, urinary tract infection and vesicoureteral refluxThe International Reflux Study in Children
J Urol
Functional constipation in children
J Urol
Wetting and functional voiding disorders
Urol Clin North Am
Pediatric hypertension as a delayed sequela of reflux-induced chronic pyelonephritis
J Urol
Focal and segmental glomerular sclerosis in reflux nephropathy
Am J Med
Pregnancy in women with reflux nephropathy
Kidney Int
Complications of pregnancy in women after childhood reimplantation for vesicoureteral reflux: an update with 25 years of follow-up
J Urol
Medical management of mild and moderate vesicoureteral reflux: followup studies of infants and young childrenA preliminary report of the Southwest Pediatric Nephrology Study Group
J Urol
The outcome of stopping prophylactic antibiotics in older children with vesicoureteral reflux
J Urol
Cessation of vesicoureteral reflux for 5 years in infants and children allocated to medical treatmentThe International Reflux Study in Children
J Urol
Antibiotics for the prevention of urinary tract infection in children: a systematic review of randomized controlled trials
J Pediatr
Antibiotic prophylaxis for the prevention of recurrent urinary tract infection in children with low grade vesicoureteral reflux: results from a prospective randomized study
J Urol
High grade vesicoureteral reflux: analysis of observational therapy
J Urol
Results of a randomized clinical trial of medical versus surgical management of infants and children with grades III and IV primary vesicoureteral reflux (United States)The International Reflux Study in Children
J Urol
Minimally invasive extravesical ureteral reimplantation for vesicoureteral reflux
J Urol
Endoscopic therapy for vesicoureteral reflux: a meta-analysis. I. Reflux resolution and urinary tract infection
J Urol
Prevalence of urinary tract infection in childhood: a meta-analysis
Pediatr Infect Dis J
Urinary tract infection, pyelonephritis, and reflux nephropathy
Urinary tract pathogens and their antimicrobial resistance patterns in Turkish children
Pediatr Nephrol
Febrile urinary tract infection in children: ampicillin and trimethoprim insufficient as empirical mono-therapy
Pediatr Nephrol
Detection of intracellular bacterial communities in human urinary tract infection
PLoS Med/Public Library of Science
Pyelonephritis and other infections, reflux nephropathy, hydronephrosis, and nephrolithiasis
Mechanisms of renal damage owing to infection
Pediatr Nephrol
A genetic basis of susceptibility to acute pyelonephritis
PLoS ONE
Feverish illness in children—assessment and initial management in children younger than 5 years
Does this child have a urinary tract infection?
JAMA
To clean or not to clean: effect on contamination rates in midstream urine collections in toilet-trained children
Pediatrics
Cleaning of the perineal/genital area before urine collection from toilet-trained children prevented sample contamination
Evid Based Med
Screening tests for urinary tract infection in children: a meta-analysis
Pediatrics
Rapid tests and urine sampling techniques for the diagnosis of urinary tract infection (UTI) in children under five years: a systematic review
BMC Pediatrics
Cited by (46)
Antibiotic Resistance in Paediatric Febrile Urinary Tract Infections
2022, Journal of Global Antimicrobial ResistanceCitation Excerpt :This is because E. coli possesses several types of adhesins that facilitate adherence of the pathogen to the uroepithelium despite the flushing effect of urine flow [27]. Moreover, once the urinary tract is invaded, an intracellular biofilm that protects the pathogen from the host immune system is produced [28]. Other common gram-negative uropathogens are Klebsiella pneumoniae, Pseudomonas aeruginosa and Proteus mirabilis.
The prevalence of kidney scarring due to urinary tract infection in Iranian children: a systematic review and meta-analysis
2019, Journal of Pediatric UrologyComputing quantitative indicators of structural renal damage in pediatric DMSA scans
2017, Revista Espanola de Medicina Nuclear e Imagen MolecularUrinary Tract Infections in the Pediatric Patient
2016, Physician Assistant ClinicsCitation Excerpt :Finally, the onset of sexual activity increases the risk of a UTI in females by the introducing bacteria into the urethra.4 Infants can have a more atypical presentation, including vomiting, feeding intolerance, diarrhea, lethargy, and fever of unknown origin.8,9 Fever of an unknown origin is the most common presenting symptom in infants.
Update on the approach of urinary tract infection in childhood
2015, Jornal de PediatriaCitation Excerpt :The persistence of palpable bladder after micturition suggests obstructive process or lower urinary tract dysfunction. In infants, the lumbar percussion may rarely show strong painful reaction (positive Giordano).34–36 Particularly in this age group, the observation of the urine stream, during the physical examination, is helpful.
Urinary tract infection in pediatrics: an overview
2020, Jornal de Pediatria
Dr. Mattoo is supported by the National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Diseases.