Urinary tract infection - Pediatrics Flashcards
1
Q
Pathogenesis of UTI (B)
A
- Most UTIs are ascending infections.
- The bacteria arise from the faecal flora, colonize the perineum, and enter the bladder via the urethra. In uncircumcised boys, the bacterial pathogens arise from the flora beneath the prepuce.
- In some cases, the bacteria causing cystitis ascend to the kidney to cause pyelonephritis.
- Rarely, renal infection occurs by hematogenous spread, as in endocarditis or in neonates.
2
Q
Etiology of UTI (a++)
A
- UTIs are caused mainly by colonic bacteria.
- In girls, 80% of all infections are caused by Escherichia coli, followed by Klebsiella, Pseudomonas, and Proteus spp.
- In boys <1 yr. of age, → Proteus, E. coli and gram-ve organisms are common.
- Staphylococcus saprophyticus and enterococcus are pathogens in both sexes
- Viral infection is rare but can occur (adenoviruses and enteroviruses)
- Mixed infection can occur.
3
Q
Risk factors of UTI (b)
A
▪ Uncircumcised male
▪ Tight clothing (underwear)
▪ Female gender
▪ Pinworm infestation
▪ Vesicoureteral reflux
▪ Constipation
▪ Toilet training
▪ Anatomic abnormality (labial adhesion)
▪ Obstructive uropathy
▪ Neuropathic bladder
▪ Urethral instrumentation
▪ Wiping from back to front in girls
4
Q
Clinical picture of UTI (a++)
A
- Asymptomatic bacteriuria: - positive urine culture without manifestations
- New-born: -Sepsis
- Infant: fever, irritability, screaming during micturition and may be associated with vomiting and poor feeding.
- Child:
o Specific urinary symptoms:
-Pain with urination (dysuria)
-Urinary frequency (needing to urinate frequently),
-Urinary urgency (feeling a compelling urge to urinate)
-Suprapubic tenderness.
-Gross haematuria
-Secondary enuresis.
o Non-specific symptoms:
-Fever (especially >39 c) usually
-with upper UTI.
-Abdominal pain (loin pain).
-Vomiting.
5
Q
Diagnosis of UTI (A++)
A
- Urine analysis: depends on proper sampling
o Toilet trained children by taking mid-stream clean catch.
o Non-toilet trained children by catheterization or suprapubic aspiration.
o Presence of WBC (pyuria) and bacteria suggests UTI
o Presence of nitrites and leucocyte esterase +ve are more suggestive for UTI - A urine culture is necessary for confirmation and appropriate therapy → Positive result if > 100.000 colonies of a single pathogen in clean
catch sample or > 10.000 urinary catheter sample or any colony count from supra pubic aspirate. - If < 10.000 colonies → suggest contaminations if clean catch or catheter samples.
- If child seriously unwell, measure serum electrolytes, CBC, CRP and ESR.
- Renal imaging → abdominal sonar, voiding cystourethrography and DMSA renal scan may be indicated in:
o Atypical UTI (sepsis, abdominal mass, poor urine flow, raised creatinine, infection with organism other than E coli …..)
o Recurrent UTI (≥ 2 times in 6 months or ≥ 4 times in 1year)
6
Q
Treatment of UTI (A++)
A
- Symptomatic treatment for fever and vomiting and adequate hydration.
- Antibiotic therapy:
-Oral antibiotics:
o Used in acute uncomplicated UTI (cystitis: 7 days) & (pyelonephritis:10 days).
o Type of oral antibiotics: oral 3rd generation cephalosporin or amoxicillin or nitrofurantoin (used for prophylaxis). If allergy is present to any one → oral trimethoprim-sulphamethoxazole.
-IV antibiotics: better combined antibiotics in a hospital (gentamycin or cefotaxime plus amoxicillin (for enterococci)) for 10-14 days are indicated in:
1. Sepsis or infants < 3 month (fear of sepsis)
2. Acute kidney injury
3. Poor hydration
4. Failure of outpatient treatment
5. Renal abscess - Urology consultation if structural abnormality, abscess, or dysfunctional elimination.
➢ Prevention: - for recurrent UTI: - Remove underlying risk factors
- Adequate hydration and bladder emptying every 3-4 hours
- Probiotic therapy: improve urogenital flora
- Cranberry juice: prevents bacterial adhesion and biofilm formation.
- UTI prophylaxis: low dose cotrimoxazole or nitrofurantoin for 6 months (controversial).
