UTI

Question 1

Who gets UTIs?

Answer 1

Women (20-30% have recurrent UTIs)

Men >50 y.o

Question 2

Host factors that predispose to UTIs

Answer 2

Kidney stones (bacterial accumulation)
Vesicourethral reflux (in children)
Neurologic problems (incomplete bladder emptying)
Prostate hypertrophy
Loss of sphincter control
Short urethra (in women)
Urinary catheters

Question 3

Host factors that prevent UTIs

Answer 3

Flushing of urinary tract
pH
Chemical content of urine

Question 4

Examples of virulence factors in uropathogenic E. coli

Answer 4

Fimbriae to adhere
Capsular polysaccharides inhibit phagocytosis
Haemolysins damage membranes

Question 5

What is the most common nosocomial infection

Answer 5

Catheter associated UTIs- risk of UTI increases by 3% each day the catheter stays in place

Question 6

S/S of UTI

- AND what is not a sign?

Answer 6

Change in the frequency of urination
Dysuria
Urgency
Hesitancy
New-onset incontinence (elderly)
Fever
Costovertebral angle tenderness (pyelonephritis)

malodorous, cloudy urine alone is not a sign of UTI

Question 7

General steps for diagnosing a UTI

Answer 7

• History
• Signs and Symptoms
• Urinanalysis
• Urine C&S

Question 8

Different ways to collect a urine sample

Answer 8

• Midstream catch (must clean periurethral area first)
• Foley catheter sample (collect from <24hr old catheter)
• Suprapubic aspiration
• Ileal conduits (in pts with cystectomy, will always be contaminated)
• Nephrostomy tubes (kidney punctured percutaneously)
• Direct cystoscopy

Question 9

Urinalysis

-signs you could have a UTI

Answer 9

• leukocyte esterase: WBCs are present, but not specific to UTI (e.g. cancer, inflammation due to catheter)
• Nitrite: + if bacteria that can reduce nitrate are present

Question 10

Quantitaive urine cultures

• use
• when to consider contamination
• sample delivery, storage

Answer 10

• Used to characterize presence +/- severity of infection
• Probably contaminated if 3 or more species grow
• Need to deliver within 2 hrs to lab, or store in fridge so bacteria doesn’t overgrow

Question 11

Antibiotic choices for empiric UTI therapy:

• Acute cystitis
• Recurrent cystitis
• Pyelonephritis
• Asymptomatic bacteriuria

Answer 11

Acute cystitis: Nitrofurantoin or fosfomycin

do not use TMP-SMX or ciprofloxacin empirically due to high levels of resistance in E.coli

Recurrent cystitis: longer course of Ab

Pyelonephritis: Cefixime or Amoxil-Clav in community. Ceftriaxone or Gentamicin in hospital (IV)

Asymptomatic bacteriuria: do not treat unless pregnant or undergoing instrumentation

Question 12

Management of:

• catheter-associated UTI
• recurrent febril UTI in paediatric patients

Answer 12

CAUTI: change or remove catheter and Ab

Paeds: US +/- voiding cystourethrogram to check fro vesciouretral reflux

Question 13

How do bacteria get into the urinary tract?

Answer 13

• ascend through the urethra

- seeding of the kidneys with bacteria in the blood (less common)

Question 14

Etiology of UTI

Answer 14

Bacterial

• Enterobacteriaceae (E. coli (80%), Klebsiella, Proteus)
• Enterococcus
• CNS
• GBS

differs in hospital-acquired UTI. Can also have candida