Overview
Definition:
A urinary tract infection (UTI) in toddlers is an infection affecting any part of the urinary system, including the kidneys, ureters, bladder, and urethra
In toddlers, it is often challenging to obtain a clean urine sample, leading to reliance on different collection methods.
Epidemiology:
UTIs are common in young children, with an incidence of 3-8% in febrile infants and toddlers
Females are more prone than males in the first year of life, but the ratio equalizes thereafter
Recurrent UTIs can lead to renal scarring and long-term complications.
Clinical Significance:
Accurate and timely diagnosis of UTIs in toddlers is crucial to prevent complications like pyelonephritis, renal scarring, hypertension, and chronic kidney disease
The method of urine collection significantly impacts diagnostic accuracy and subsequent management.
Clinical Presentation
Symptoms:
Fever, often unexplained
Irritability and poor feeding
Vomiting and diarrhea
Foul-smelling urine
Dysuria (crying during urination)
Increased frequency or urgency of urination
Abdominal pain or flank pain
New onset of daytime or nighttime incontinence in a toilet-trained child.
Signs:
Fever
Tenderness in the suprapubic or flank region
Abdominal distension
Lethargy or irritability
Signs of dehydration
Poor growth velocity in recurrent cases.
Diagnostic Criteria:
Presence of significant bacteriuria on urine culture (typically ≥10^5 colony-forming units/mL for clean-catch or midstream samples, or ≥10^3 CFU/mL for catheterized samples)
Clinical signs and symptoms suggestive of UTI in the context of a positive urine culture
Positive urinalysis findings (e.g., pyuria, bacteriuria, positive leukocyte esterase) can support the diagnosis but are not definitive.
Diagnostic Approach
History Taking:
Detailed history of fever, feeding, voiding habits, and any previous UTIs
Ask about incontinence in toilet-trained children
Inquire about bowel habits, as constipation can be associated with UTIs
Note any history of urinary tract abnormalities.
Physical Examination:
General assessment for fever, dehydration, and irritability
Abdominal examination for tenderness, distension, or masses
Genital examination to rule out local causes of irritation or infection
Assess for CVA tenderness (costovertebral angle tenderness) if tolerated.
Investigations:
Urinalysis: Dipstick for leukocytes and nitrites
Microscopy for white blood cells (pyuria), red blood cells, and bacteria
Urine Culture and Sensitivity: The gold standard for diagnosis
Obtain urine via the most appropriate method
Urine bag collection is prone to contamination
Catheterization provides a cleaner sample but can still have a low contamination rate
Suprapubic aspiration (SPA) yields the cleanest sample but is invasive
Imaging: Renal ultrasound (to assess for structural abnormalities, hydronephrosis, abscesses)
Voiding cystourethrogram (VCUG) if vesicoureteral reflux (VUR) is suspected, especially after the first UTI in infants and young children or recurrent UTIs
DMSA scan for assessing renal scarring.
Differential Diagnosis:
Gastroenteritis (vomiting, diarrhea)
Pneumonia (fever)
Meningitis (fever, irritability)
Other sources of fever (e.g., otitis media, pharyngitis)
Vulvovaginitis in girls
Balanitis in boys
Dehydration.
Specimen Collection Methods
Urine Bag Collection:
Least invasive method for infants and non-toilet-trained toddlers
Adhesive bag applied to the perineum
Prone to significant contamination from skin flora, stool, and perineal secretions, leading to high false-positive rates
Requires careful hygiene and frequent monitoring for collection
If positive, repeat sample via a more reliable method is often needed.
Catheterization:
Insertion of a sterile catheter into the bladder via the urethra
Provides a less contaminated sample than a urine bag
Recommended for toddlers who cannot void on demand or when a clean-catch is not feasible
Still carries a risk of iatrogenic infection or contamination
Use sterile technique.
Suprapubic Aspiration Spa:
Direct aspiration of urine from the bladder through the abdominal wall using a needle
Considered the most sterile method and has the lowest contamination rate
Indicated when other methods are unavailable, inconclusive, or when a definitive sterile sample is critical, especially for neonates or infants with suspected UTIs
It is invasive and carries risks like bleeding or bowel perforation if not performed correctly.
Clean Catch Midstream:
For toddlers who can cooperate
Perineal area cleaned thoroughly, and the child voids
The initial stream is discarded, and midstream urine is collected in a sterile container
Ideal for obtaining a high-quality sample but often difficult to achieve in this age group.
Management
Initial Management:
Prompt antibiotic therapy based on suspected organism and local resistance patterns
Empiric therapy is usually initiated while awaiting culture results
Ensure adequate hydration
Antipyretics for fever management.
Medical Management:
Antibiotic selection depends on the suspected pathogen, patient age, severity of infection, and local resistance data
Common choices include cephalosporins (e.g., cefixime, ceftriaxone), trimethoprim-sulfamethoxazole, or amoxicillin-clavulanate
Oral antibiotics for cystitis and uncomplicated pyelonephritis
IV antibiotics for severe infections or impaired oral intake
Duration of therapy typically 7-14 days depending on the site of infection.
Surgical Management:
Rarely indicated for uncomplicated UTIs
Surgical intervention may be required for structural abnormalities predisposing to UTIs, such as posterior urethral valves, or in cases of severe renal abscesses or obstructions
Long-term management may involve prophylactic antibiotics or surgical correction of VUR in select cases.
Supportive Care:
Encourage fluid intake to promote urine output
Monitor for signs of dehydration
Monitor vital signs and urine output closely
Pain management as needed
Patient and family education regarding UTI prevention and follow-up.
Complications
Early Complications:
Sepsis or bacteremia
Acute kidney injury
Perinephric abscess
Dehydration.
Late Complications:
Renal scarring leading to hypertension
Chronic kidney disease
Renal failure
Recurrent UTIs.
Prevention Strategies:
Prompt and adequate treatment of UTIs
Evaluation for underlying structural abnormalities
Management of constipation
Judicious use of antibiotics
Educating parents on hygiene and fluid intake
Prophylactic antibiotics may be considered in specific high-risk scenarios.
Key Points
Exam Focus:
Understanding the nuances of urine specimen collection in toddlers is critical for accurate diagnosis
Know the pros and cons of bag, catheter, and SPA
Recognize that a positive urine bag culture in an asymptomatic child might be contamination.
Clinical Pearls:
Always consider UTI in febrile toddlers, especially without a clear source
A clean urine culture is paramount for diagnosis and guiding therapy
When in doubt, repeat the urine sample using a more reliable method like catheterization or SPA.
Common Mistakes:
Relying solely on a urine bag culture without clinical correlation
Delaying antibiotic treatment while waiting for culture results in symptomatic children
Not investigating for underlying anatomical abnormalities in recurrent UTIs.