الفهرس 
Embryological and anatomical considerationsOnly 14 pages are availabe for public view
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Abstract
The prevalence of urinary tract infection (UTI) in febrile children younger than two years varies from <1 to 16 percent depending upon age, sex, circumcision status in boys, and race/ethnicity (table 4).
The prevalence of UTI in older children with urinary tract symptoms and/or fever is approximately 8 percent.
Escherichia coli is the most common bacterial cause of UTI.
A variety of host factors influence the predisposition to UTI in children. These include female sex, genetic factors, urinary tract anomalies, bladder and bowel dysfunction, vesicoureteral reflux (VUR), sexual activity, and bladder catheterization in addition to those mentioned above for febrile young children (eg, lack of circumcision, temperature >39° C [102.2°F]).
Bladder and bowel dysfunction is an important and often overlooked factor in the pathophysiology of UTI in children. It is characterized by an abnormal elimination pattern (frequent or infrequent voids, urgency, infrequent stools), bladder and/or bowel incontinence, and withholding maneuvers.
Children with an abnormal renal ultrasonographic finding or with a combination of high fever (≥39°C) and an etiologic organism other than E. coli are have a higher risk of developing renal scarring than children without these characteristics.
Fever may be the only sign of urinary tract infection (UTI) in infants and young children. Older children may have urinary symptoms (eg, abdominal pain, back pain, dysuria, frequency, new-onset urinary incontinence).
Important aspects of the history in a child with suspected UTI include features of the acute illness (eg, fever, urinary symptoms) and risk factors for UTI (table 4).
The examination of the child with suspected UTI should include measurement of blood pressure, temperature, and growth parameters; abdominal examination for tenderness or mass; assessment of suprapubic and costovertebral tenderness; examination of the external genitalia; evaluation of the lower back for signs of occult myelomeningocele; and a search for other sources of fever.
The laboratory evaluation for the child with suspected UTI includes obtaining a urine sample for a dipstick and/or microscopic evaluation and urine culture (table 6). Urine culture is necessary to make the diagnosis.
We suggest that urine samples be obtained for urinalysis and culture in the following patients (algorithm 1):
Girls and uncircumcised boys younger than two years with at least one risk factor for UTI (history of UTI, temperature >39ºC, fever without apparent source [particularly if the child will be treated with antibiotics], ill appearance, suprapubic tenderness, fever >24 hours, or nonblack race).
Circumcised boys younger than two years with suprapubic tenderness or at least two risk factors for UTI (history of UTI, temperature >39ºC, fever without apparent source, ill appearance, suprapubic tenderness, fever >24 hours, or nonblack race).
Girls and uncircumcised boys older than two years with any of the following urinary or abdominal symptoms (abdominal pain, back pain, dysuria, frequency, high fever, or new-onset incontinence).