Basics
Description
- Bacteria colonize via retrograde contamination of rectal or perineal flora:
- Infants " ”often hematogenous spread
- Older children " ”vesicoureteral reflux (VUR) major risk
- UTI is defined by culture of a single organism of >10,000/mL on a catheterized or suprapubic specimen. Other collection techniques are not routinely used in young children for definitive diagnosis.
- In infants 0 " “3 mo old, UTI is associated with a 30% incidence of sepsis.
- Predisposing factors:
- Poor perineal hygiene
- Short urethra of female
- Female > male
- Infrequent voiding
- Constipation
- Sexual activity
- Male circumcision probably reduces risk
Etiology
- UTI found in 4 " “7% of febrile infants
- Bacterial agents:
- Escherichia coli accounts for 80%
- Klebsiella pneumoniae
- Staphylococcus aureus
- Enterobacter species
- Proteus species
- Pseudomonas aeruginosa
- Enterococcus species
Diagnosis
UTIs in children may be difficult to diagnose without lab confirmation. ‚
Signs and Symptoms
History
- Often nonspecific
- Neonates:
- Manifestations of sepsis
- Feeding difficulties
- Irritability, listlessness
- Fever, hypothermia
- 1 mo " “3 yr of age:
- Fever
- Irritability
- Vomiting, diarrhea
- Abdominal pain
- Poor feeding, failure to thrive
- Hematuria
- In girls <2 yr, an increased risk is associated with those having ≥3 factors (<12 mo old, white, temperature ≥39 ‚ °C, absence of other source of fever, fever ≥2 days)
- Children >3 yr of age:
- Dysuria
- Frequency
- Enuresis
- New onset of urinary incontinence
- Pain: Abdominal, suprapubic, back, costovertebral angle (CVA)
- Fever
- Hematuria
- Malodorous cloudy urine
- Systemic toxicity: High fever and chills with CVA tenderness
- Complications:
- Recurrent UTI
- Pyelonephritis
- Chronic renal failure:
- Scarring probably may be reduced by early detection and intervention
- Perinephric abscess
- Bacteremia/sepsis
- Urolithiasis
Physical Exam
- Vital signs, esp. temperature and blood pressure
- Toxicity
- Growth parameters
- Abdomen: Tenderness, esp. CVA pain
- GU: Genitalia
Essential Workup
- UA with microscopic RBC and WBC counts and Gram stain for bacteria:
- UA alone has low diagnostic sensitivity in infants.
- Causes of pyuria besides UTI include chemical (bubble bath) or physical (masturbation) irritation, dehydration, renal tuberculosis, trauma, acute glomerulonephritis, respiratory infections, appendicitis, pelvic infection, and gastroenteritis.
- Leukocyte esterase correlates with presence of pyuria.
- Positive nitrite test indicates presence of bacteria capable of fixing nitrate. False-negative tests common
- Gram stain of urinary sediment is more reliable than dipstick methods of diagnosis and superior to traditional UA.
- Up to 80% of UAs in neonates with documented UTIs may be normal.
- Urine culture:
- Specimen should be cultured within 30 min or refrigerated.
- False-negative results may be caused by dilution, improper culture medium, recent antimicrobial therapy, fastidious organisms, bacteriostatic agent in urine, and complete obstruction of ureter.
- Clean-catch and bag specimens
- Clean catch in cooperative male children
- Plastic bag collection adequate for UA (70% contamination rate).
- Clean the perineum (females) and glans (males) before application.
- Can be used as a screening tool to rule out an infection if patient is not placed on antibiotics empirically and follow-up culture possible if the initial assessment is suggestive of infection.
- Catheterization is the preferred technique to obtain urine because contamination is common with bag collection and clean catch:
- Bladder catheterization:
- Acceptable in all infants
- Higher success rate than suprapubic aspiration
- Aseptic technique essential
- Discarding the 1st 1 " “2 mL of urine before collecting specimen reduces contamination.
- Suprapubic aspiration is used on rare occasion and does provide a good specimen:
- Most useful in infants
- Full bladder optimal
- Uncommonly used
- Ultrasound may be useful adjunctive measure to improve yield.
Diagnosis Tests & Interpretation
Lab
- CBC and blood culture for young children with fever or nonspecific symptoms and no source on exam. Consider additional evaluation as appropriate.
- Electrolytes, BUN, creatinine:
- Check if there is dehydration, pyelonephritis, or recurrent infection.
Imaging
- Children requiring radiologic evaluation:
- Infants <3 mo of age
- Males (increased association with anomaly) with 1st UTI
- Clinical signs and symptoms consistent with pyelonephritis
- Clinical evidence of renal disease
- Some suggest that girls <3 yr of age with a 1st UTI should be studied.
- Females >3 yr of age
- 1st UTI in patients who have a family history of UTIs, abnormal voiding pattern, poor growth, HTN, urinary tract anomalies, or failure to respond promptly to therapy
- 2nd UTI
- Voiding cystoureterogram (VCUG):
- UTI is often associated with VUR and other genitourinary abnormalities and identified by VCUG. The importance of identifying VUR has been questioned.
- Renal/bladder ultrasound (US):
- Ultrasonography is useful in excluding obstructive lesion and identifying children with solitary/ectopic kidney and some patients with moderate renal damage/scarring:
- Renal/bladder US is indicated to identify anatomic abnormalities. Should be done in children <2 yr with 1st febrile UTI, children with recurrent febrile UTIs, children with a UTI and family history of GU disease, poor growth, or hypertension as well as those children who do not respond as anticipated to antibiotics.
- Nuclear cystogram (DMSA) may be substituted for VCUG in females. Its role is being clarified.
- Further evaluation with nuclear medicine studies depends upon the grade of VUR and response to treatment
Differential Diagnosis
- Infection:
- Vulvovaginitis
- Viral cystitis
- Urethritis (Neisseria gonorrhoeae or Chlamydia trachomatis)
- Glomerulonephritis
- Appendicitis
- Trauma:
- Chemical irritation/cystitis
- Perineal
- Sexual abuse
- Genitourinary
- Masturbation
- Foreign body
- Nephrolithiasis
- Diabetes
Treatment
Initial Stabilization/Therapy
- Treat infants <3 mo old presumptively for sepsis if febrile and/or toxic until blood and other appropriate cultures are final.
- Airway intervention for septic/acidotic infants with depressed respiratory drive
- Bolus of 20 mL/kg 0.9% NS for dehydration, hypovolemia, or sepsis; may repeat
Ed Treatment/Procedures
- Initiate IV antibiotics in all febrile infants <3 mo with UTI:
- Ampicillin and gentamicin in neonates
- Cephalosporins after 4 " “8 wk of age
- Outpatient oral antibiotic for 10 " “14 days for children discharged. Should reflect local resistance patterns. Once sensitivity is known, antibiotic may need to be changed:
- Amoxicillin
- Amoxicillin/clavulanate
- Cephalexin
- Trimethoprim " “sulfamethoxazole (TMP " “SMX)
- Many suggest 3rd-generation cephalosporin (cefixime, cefdinir) as 1st-line drug in treatment of children without GU anomaly because of changing resistance patterns. Oral therapy is generally adequate although close follow-up is essential to monitor clinical response and sensitivity of the etiologic organism.
- Recent UTI may provide information related to sensitivities in children with recurrent UTIs
- Length of treatment in children with afebrile UTI may be shortened to 5 days in children >2 yr. The short course is still not generally recommended in children with febrile UTI.
Medication
First Line
- Amoxicillin: 40 mg/kg/24 h PO q8h
- Amoxicillin/clavulanate: 40 mg/kg/24 h PO q8h
- Ampicillin: 100 mg/kg/24 h IV q6h
- Cefdinir 14 mg/kg/24 h PO QD
- Cefixime 16 mg/kg/24 h PO on 1st day followed by 8 mg/kg/24 h PO QD
- Ceftriaxone: 50 " “75 mg/kg/24 h q12 " “24h IV or IM
- Cephalexin: 50 mg/kg/24 h PO q6 " “12h
- Gentamicin: 2.5 mg/kg/dose IV q8h if full-term and age >7 days; 2.5 mg/kg/dose IV q12h if full-term and age 0 " “7 days (special dosing regimens in infants <36 wk postconceptual age)
- TMP " “SMX (Bactrim or Septra suspension): 5 mL liquid (of 40/200 per 5 mL) per 10 kg per dose PO BID
Follow-Up
Disposition
Admission Criteria
- Infants <3 mo
- Dehydration
- Ill appearance/toxicity/sepsis
- Suspected pyelonephritis
- Urinary obstruction
- Vomiting, inability to retain medications
- Failure to respond to outpatient therapy
- Immunocompromised patient
- Renal insufficiency
- Foreign body (indwelling catheter)
- Pregnant patient
Discharge Criteria
- Sufficiently hydrated
- Low risk for sepsis or meningitis
- Nontoxic
- Able to take oral antibiotics; compliant
Issues for Referral
- Patients needing admission often require a pediatrician, urologist, or infectious disease consultant, esp. if there is VUR, renal anomaly, impaired renal function, recurrent infection, or hypertension.
- Good follow-up is mandatory.
Followup Recommendations
Monitoring of urine for sterility, further evaluation for underlying pathology, and following growth pattern ‚
Pearls and Pitfalls
- UTI may require lab confirmation of clinical suspicion. Signs and symptoms are often nonspecific.
- Febrile infants with UTI may be bacteremic.
- Neonates with UTI may have normal urinalysis.
Additional Reading
- American Academy of Pediatrics, Subcommittee on Urinary Tract Infection. Urinary tract infection: Clinical practice guidelines for the diagnosis and management of the initial UTI in febrile infants and children 2 to 24 months. Pediatrics. 2011;128:595 " “610.
- Hoberman ‚ A, Keren ‚ R: Antimicrobial prophylaxis for urinary tract infection in children. N Engl J Med. 2009;361:1804 " “1806.
- Marks ‚ SD, Gordon ‚ I, Tulls ‚ K. Imaging in childhood urinary tract infection: Time to reduce investigations. Pediatr Nephrol. 2008;23:9 " “17.
- Peniakov ‚ M, Antonelli ‚ J, Naor ‚ O, et al. Reduction of contamination of urine samples obtained by in-out catheterization by culturing the later urine stream. Pediatr Emerg Care. 2004;6:418 " “419.
- Sahsi ‚ RS, Carpenter ‚ CR. Does this children have a urinary tract infection? Ann Emerg Med. 2009;53:680 " “684.
- Wald ‚ E. Urinary tract infections in infants and children: A comprehensive overview. Curr Opin Pediatr. 2004;16:85 " “88.
See Also (Topic, Algorithm, Electronic Media Element)
UTI, Adult ‚
Codes
ICD9
- 041.49 Other and unspecified Escherichia coli [E. coli]
- 593.70 Vesicoureteral reflux unspecified or without reflux nephropathy
- 599.0 Urinary tract infection, site not specified
- 041.3 Klebsiella pneumoniae
- 599.70 Hematuria, unspecified
ICD10
- B96.20 Unsp Escherichia coli as the cause of diseases classd elswhr
- N13.70 Vesicoureteral-reflux, unspecified
- N39.0 Urinary tract infection, site not specified
- B96.1 Klebsiella pneumoniae as the cause of diseases classd elswhr
- R31.9 Hematuria, unspecified
SNOMED
- 68566005 urinary tract infectious disease (disorder)
- 197811007 vesicoureteric reflux (disorder)
- 301011002 Escherichia coli urinary tract infection (disorder)
- 186435004 Friedlanders bacillus infection (disorder)
- 34436003 Blood in urine (finding)