Diagnostic Considerations
Conditions that can produce the symptoms of urinary tract infection (UTI), along with those listed in the Differentials section, include the following:
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Epididymitis
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Orchitis
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Prostatitis
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Urethritis
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Pregnancy
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Urolithiasis
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Bladder and bowel dysfunction
Children with uninhibited detrusor contractions may experience symptoms of voiding dysfunction (eg, urgency, frequency, hesitancy, dribbling, or incontinence) in the absence of infection or local irritation. In attempts to prevent incontinence during a detrusor contraction by voluntarily increasing outlet resistance, however, these children may promote the development of a UTI. One theory is that bacteria-laden urine in the distal urethra may be milked back into the urinary bladder (urethrovesical reflux).
Increased outlet resistance may be achieved by using various posturing maneuvers, such as the following:
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Tightening of the pelvic-floor muscles
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Applying direct pressure to the urethra with the hands
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Performing the Vincent curtsy, which consists of squatting on the floor and pressing the heel of one foot against the urethra
Voiding dysfunction is not usually encountered in a child without neurogenic or anatomic abnormality of the bladder until the child is in the process of achieving daytime urinary control.
Adolescent girls are more likely to have vaginitis (35%) than UTI (17%).Adolescent girls who are diagnosed with cystitis frequently have a concurrent vaginitis. Pregnancy must be considered in adolescent girls who present with symptoms of UTI and/or vaginitis and who are sexually active.
Differential Diagnoses
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Fever in the Neonate and Young Child
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Pinworms
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Vulvovaginitis
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Application of low-risk criteria for and approach to the febrile infant: A reasonable approach for treating febrile infants younger than 2 months who have a temperature of greater than 38°C.
Tables
- Table 1. Urinalysis for Presumptive Diagnosis of Urinary Tract Infection*
- Table 2. Quantitative Urine Culture for the Diagnosis of Urinary Tract Infection*
- Table 3. Antibiotic Agents for Parenteral Treatment of a Urinary Tract Infection
- Table 4. Antibiotic Agents for the Oral Treatment of Urinary Tract Infection
- Table 5. Antibiotic Agents to Prevent Reinfection
Method |
Findings |
Bright-field or phase-contrast microscopy of centrifuged urinary sediment |
Bacteria |
Gram stain of uncentrifuged or centrifuged urinary sediment |
Bacteria |
Nitrite and leukocyte esterase test |
Positive = UTI likely |
Nitrite test |
Positive = UTI probable |
Leukocyte esterase test |
Positive = UTI probable |
*Negative microscopic findings for bacteria do not rule out a UTI, nor do negative results of dipstick testing for nitrite and leukocyte esterase. False-negative nitrite readings are especially common in children. |
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Method |
Finding |
Suprapubic aspiration |
If a UTI is present, bacteria are likely to be proliferating in bladder urine with growth of any organism except 2000-3000 CFU/mL coagulase-negative staphylococci. |
Catheterization in a girl or midstream, clean-void collection in a circumcised boy |
Febrile infants and children with UTI usually have >50,000 CFU/mL of a single urinary pathogen; however, UTI may be present with 10,000-50,000 CFU/mL of a single organism.* |
Midstream, clean-void collection in a girl or uncircumcised boy |
UTI is indicated when >100,000 CFU/mL of a single urinary pathogen is present in a symptomatic patient. Pyuria usually present. A UTI may be present with 10,000-50,000 CFU/mL of a single bacterium.* |
Any method in a girl or boy |
If the patient is asymptomatic, bacterial growth is usually >100,000 CFU/mL of the same organism on different days. If pyuria is absent, this result probably indicates colonization rather than infection. |
*Patients with urinary frequency (ie, decreased bladder incubation time) are those most likely to have bacteria proliferating in the urinary bladder in the presence of low colony counts. |
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Drug |
Dosage and Route |
Comment |
Ceftriaxone |
50-75 mg/kg/day IV/IM as a single dose or divided q12h |
Do not use in infants < 6 wk of age; parenteral antibiotic with long half-life; may displace bilirubin from albumin |
Cefotaxime |
150 mg/kg/day IV/IM divided q6-8h |
Safe to use in infants < 6 wk of age; used with ampicillin in infants aged 2-8 wk |
| Ceftolozane/tazobactam | 30 mg/kg IV q8h x7-14 days | Indicated for complicated UTIs approved in children from birth and older; CrCl must be above 50 mL/min/1.73 m2 |
Ampicillin |
100 mg/kg/day IV/IM divided q8h |
Used with gentamicin in neonates < 2 wk of age; for enterococci and patients allergic to cephalosporins |
Gentamicin |
Term neonates < 7 days: 3.5-5 mg/kg/dose IV q24h Infants and children < 5 years: 2.5 mg/kg/dose IV q8h or single daily dosing with normal renal function of 5-7.5 mg/kg/dose IV q24h Children ≥5 y: 2-2.5 mg/kg/dose IV q8h or single daily dosing with normal renal function of 5-7.5 mg/kg/dose IV q24h |
Monitor blood levels and kidney function if therapy extends >48 h |
Note: CrCl = creatinine clearance; IM = intramuscular; IV = intravenous; q = every; UTI = urinary tract infection. |
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Protocol |
Daily Dosage |
Sulfamethoxazole and trimethoprim (SMZ-TMP) |
30-60 mg/kg SMZ, 6-12 mg/kg TMP divided q12h |
Amoxicillin and clavulanic acid |
20-40 mg/kg divided q8h |
Cephalexin |
50-100 mg/kg divided q6h |
Cefixime |
8 mg/kg q24h |
Cefpodoxime |
10 mg/kg divided q12h |
Nitrofurantoin* |
5-7 mg/kg divided q6h |
*Nitrofurantoin may be used to treat cystitis. It is not suitable for the treatment of pyelonephritis, because of its limited tissue penetration. |
|
Agent |
Single Daily Dose |
Nitrofurantoin * |
1-2 mg/kg PO |
Sulfamethoxazole and trimethoprim (SMZ-TMP) * |
5-10 mg/kg SMZ, 1-2 mg/kg TMP PO |
Trimethoprim |
1-2 mg/kg PO |
*Do not use nitrofurantoin or sulfa drugs in infants younger than 6 weeks. Reduced doses of an oral first-generation cephalosporin, such as cephalexin at 10 mg/kg, may be used until the child reaches age 6 weeks. Ampicillin or amoxicillin are not recommended because of the high incidence of resistant E coli. |
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