Urinary Tract Infections

Question 0

What is the UTI recurrence rate?

Answer 0

20-50%

Question 1

When do UTIs peak in frequency?

Answer 1

In infancy and during toilet training

Question 2

UTI gender ratios at 1 year

Answer 2

1 year: M:F = 1:10

Question 3

Predisposing factors (4)

Answer 3

Bladder dysfunction
Constipation
Urinary tract obstruction such as posterior urethral valves
Not being breastfed

• hygiene habits and type of diapers do NOT affect risk of UTI…

Question 4

Signs and symptoms (newborn and older)

Answer 4

Newborn: jaundice, sepsis, FTT, fever, irritable
Older children: diarrhea, FTT, vomiting, fever, strong smelling urine, abdo/flank pain, urinary incontinence, dysuria, urgency

Question 5

Important things to do check on physical exam

Answer 5

Abdominal exam => constipation
Suprapubic/ lower back tenderness
External genitalia
Other sources of fever => diarrhea, URTI/LRTI, AOM, sepsis

Question 6

How to collect urine (infants vs. toilet trained)

Answer 6

Infants: urine bag (contamination risk), sterile catheter (uncomfortable), suprapubic bladder puncture (painful and difficult but sterile)
Toilet trained: mid stream catch

Question 7

Definitive Dx of a UTI

Answer 7

Culture! (~10^8 CFU/L) from clean catch

Common pathogens: E.coli!!!, klebsiella, proteus, enterobacter, pseudomonas (Gm -); enterococci, group B strep, staph (Gm +)

Dipstick leukocyte esterase and nitrites are 80-90% sensitive, nitrites can be falsely negative

Consider LP if less than 4 weeks old

Question 8

Treatment (2 months)

Answer 8

2 months: oral ABx (cefixime (aka suprax); clavulin; TMP-SFX) x 10 days)

Always check BP, renal function (creatinine/BUN), adequate hydration

Question 9

Who needs UTI prophylaxis?

Answer 9

Grade 4 or 5 vesicoureteral reflux => reflux into ureter and renal pelvis with moderate to severe distention
Before voiding cystourethrogram (VCUG)?

Rx: TMP-SMX, nitrofurantoin, amoxicillin (newborns); qhs

Question 10

What imaging tests might be done and why?

Answer 10

Abdo US to screen for hydronephrosis during acute illness (see dilated renal pelvis, can lead to scarring, end stage renal failure and HTN)
VCUG to screen for VUR and posterior urethral valve, NOT done during acute illness!

Image children at greater risk of atypical UTI: <1 month, seriously ill, urinary retention/dribbling, abdo mass, persistently elevated creatinine, no clinical improvement after 2 days, culture positive for NON E.coli bacteria