UTI

Question 1

Upper UTI:

Answer 1

pyelonephritis

Question 2

Lower UTI:

Answer 2

cystitis, urethritis, prostatitis, epididymitis

Question 3

Prevalence at:

• 0 - 6mths
• 1 - adult
• elderly (age >65)

Answer 3

• 0 - 6mths: male > female
• 1 - adult: female > male
• elderly (age >65): equal

Question 4

Common organisms for

1. Ascending
2. Descending

Answer 4

1. Ascending: E. coli, Klebsiella pneumoniae, Proteus spp, Staphylococcus saprophyticus
2. Descending: Staphylococcus aureus, Mycobacterium tuberculosis

Question 5

Host Defense Mechanisms against development of UTI

Answer 5

Bacteria stimulates micturition with increased diuresis -> emptying of bladder
Antibacterial properties of urine & prostatic secretion
Anti adherence mechanisms of bladder (bacterial attachment)
Inflammatory response with polymorphonuclear leukocytes (PMNs) -> phagocytosis -> prevent/control spread

Question 6

Factors in determining development of UTI besides host defense mechanisms

Answer 6

Size of the inoculum: increased with urinary retention/obstruction
Virulence/pathogenicity: bacteria with pili e.g. E. coli resistant to washout or anti-adherence

Question 7

Risk Factors for UTI

Answer 7

1. Females > males: Pregnancy, Use of diaphragms & spermicides
2. Sexual intercourse
3. Abnormalities of the urinary tract eg prostatic hypertrophy, kidney stones, urethral strictures, vesicoureteral reflux
4. Neurologic dysfunctions eg stroke, diabetes, spinal cord injuries
5. Anti cholinergic drugs
6. Catheterization and other mechanical instrumentation
7. Diabetes
8. Genetic association (positive family history)
9. Previous UTI

Question 8

Prevention of UTI

Answer 8

1. drink lots of fluid
2. urinate frequently and when you feel the urge
3. urinate shortly after sex
4. wear cotton underwear and loose-fitting clothes
5. modify birth control (diaphragm, spermicide, unlubricated or spermicidal condoms)

Question 9

What counts as uncomplicated UTI?

Answer 9

healthy, premenopausal, non-present women without Hx of abnormalities of urinary tract

Question 10

Symptoms of cystitis

Answer 10

dysuria, urgency, frequency, nocturia, suprapubic heaviness or pain, gross hematuria

Question 11

Symptoms of pyelonephritis

Answer 11

Systemic: fever >38C, rigors, headache, nausea, vomiting, malaise
Pain: flank, renal punch (costovertebral tenderness), abdominal

Question 12

Symptoms of UTI in elderly (less urinary symptoms)

Answer 12

1. altered mental status (drowsy, less alert)

2. less appetite

Question 13

Methods of urine collection

Answer 13

1. Midstream clean catch
2. Catheterization
3. Suprapubic bladder aspiration

Question 14

Objective markers from microscopic examination

Answer 14

Pyuria: WBC >10cells/mm3 (most indicative)
Hematuria: >5/HPF or gross (non-specific)
Gram-stain
WBC casts: masses of cells/proteins in renal tubules -> upper UTI

Question 15

Common contaminants in UFEME

Answer 15

Yeast (not pathogen)

Squamous epithelial cells (if >5)

Question 16

What do the dipstick indicators mean? (nitrite and leukocyte esterase)

Answer 16

1. Nitrite: gram-neg bacteria (>10^5 bacteria/mL)
   - False negative: gram-pos or P. aeruginosa, low urinary pH, frequent voiding/dilute urine
2. Leukocyte esterase: correlate w/ pyuria

Question 17

What are healthcare-associated risk factors for healthcare associated or complicated UTI?

Answer 17

1. Hospitalization in the last 90 days
2. Current hospitalization >2 days
3. Residence in nursing home
4. Abx use in the last 90 days
5. Home infusion therapy

Question 18

What is characteristic of complicated or healthcare-associated UTI?

Answer 18

More drug resistant organisms e.g. ESBLs are likely

Question 19

When should you treat asymptotic UTI?

Answer 19

1. Pregnant: reduce pyelonephritis, risk of preterm labour and low birth weight
2. Invasive procedures w/ mucosal trauma: culture then start abx on culture and sensitivity 12-24h before procedure

Question 20

1st line Empiric antibiotics for uncomplicated cystitis

Answer 20

PO cotrimoxazole 800/160 mg bid x 3d or
PO nitrofurantoin 50 mg qid x 5d
PO fosfomycin 3 g single dose

Question 21

alternative empiric antibiotics for uncomplicated cystitis

Answer 21

1. PO beta lactams x 3-7d
   - PO cefuroxime 250mg bd
   - PO cephalexin 500mg bd
   - PO augmentin 625mg bd
2. PO fluoroquinolones x 3d
   - PO ciprofloxacin 250mg bd
   - PO levofloxacin 250mg od

Question 22

Abx duration for complicated cystitis in women

Answer 22

Longer duration of 7-14d

- PO Fosfomycin 3g EOD x3 doses

Question 23

Empiric abx for CA-pyelonephritis

Answer 23

1. PO fluoroquinolones
   - ciprofloxacin 500 mg bd x 7d
   - levofloxacin 750 mg od x 5d
2. PO cotrimoxazole 160/800 mg bd x 14d
3. PO Beta-lactams x 10-14d
   - cephalexin 500 mg bid
   - amoxicillin/clavulanate 625 mg tds

Question 24

Initial IV therapy for severely ill patients who require hospitalisation or cannot take oral drug (CA-pyelonephritis)

Answer 24

IV ciprofloxacin 400mg bid 
IV cefazolin 1g q8h
IV augmentin 1.2g q8h and/or 
IV/IM gentamicin 5mg/kg 
***Switch to oral when patient improved or able to take orally

Question 25

Empiric abx for UTI in men without concern for prostatitis

Answer 25

Same as regimen for complicated cystitis in women but longer duration

Question 26

Empiric abx for UTI in men with cystitis (concern for prostatitis) or with prostatitis

Answer 26

PO ciprofloxacin 500 mg twice daily x10-14d | PO co trimoxazole 800/160 mg twice daily x7d ok

Question 27

How long is the abx duration for UTI in men with confirmed prostatitis?

Answer 27

6 weeks

Question 28

Empiric abx for nosocomial/healthcare-associated pyelonephritis

Answer 28

Duration: 7-14 days IV cefepime 2g q12h +/ IV amikacin 15mg/kg/d or IV imipenem 500mg q6h or IV meropenem 1g q8h For less sick patients: - PO levofloxacin 750mg od - PO ciprofloxacin 500mg bid

Question 29

When is the onset of nosocomial UTI?

Answer 29

>48h post admission

Question 30

What is the rationale of choosing broad spectrum B-lactams for nosocomial/healthcare-associated pyelonephritis?

Answer 30

Possibility of P. aeruginosa and other resistant bacteria (e.g. ESBL producing E. coli and Klebsiella)

Question 31

Risk factors for development of catheter-associated UTI

Answer 31

1. Duration of catheterisation: +3-5% risk per day 2. Colonisation of drainage bag, catheter and periurethral segment 3. DM 4. Female 5. Renal function impairment 6. Poor quality of catheter care, including insertion

Question 32

Definition of Catheter-associated UTI

Answer 32

1. UTI symptoms/signs w/ no other identified source of infection 2. 10^3 cfu/mL of ≥1 bacterial species in: - 1 catheter urine specimen in patients with indwelling urethral/suprapubic, or intermittent catheterization OR - midstream voided urine specimen when catheter has been removed within the previous 48 h

Question 33

After 28 days, catheter-associated UTI is likely to be ___. Before 7 days, catheter-associated UTI is likely to be ___ reflecting that prevailing the environment.

Answer 33

After 28 days, catheter-associated UTI is likely to be polymicrobial. Before 7 days, catheter-associated UTI is likely to be single organisms reflecting that prevailing the environment.

Question 34

What is the first thing to consider for catheter-associated UTI?

Answer 34

Consider removal of catheter Removal not possible: Indwelling catheter has been in place for >2 wks at the onset of CA UTI and is still indicated -> replace the catheter - Rationale: to hasten resolution of symptoms and to reduce the risk of subsequent CA bacteriuria and CA UTI

Question 35

Are cultures required for catheter-associated UTI?

Answer 35

Yes, urine culture must be taken before initiation of antibiotics.

Question 36

What counts as symptomatic CA-UTI for initiation of abx?

Answer 36

1. new onset or worsening of fever, rigors 2. altered mental status, malaise, or lethargy with no other identified cause 3. flank pain; costovertebral angle tenderness; acute hematuria; pelvic discomfort

Question 37

Empiric abx and abx duration for CA-UTI

Answer 37

Duration: 7d for prompt resolution, otherwise 10-14 days - IV imipenem 500mg q6H or IV meropenem 1g q8h - IV cefepime 2g q12H +/ IV amikacin 15mg/kg (1 dose) - Mild CA UTI: PO/ IV levofloxacin 750mg x 5d - PO Co trimoxazole 960mg bid x 3d (for women ≤65yo w/ CA UTI w/o upper UTI symptoms after an indwelling catheter has been removed)

Question 38

Why is ertapenem not used for CA-UTI?

Answer 38

not effective against Pseudomonas aeruginosa

Question 39

What are the abx to avoid in pregnant women with UTI?

Answer 39

1. Cotrimoxazole (1st & 3rd trimester) 2. Nitrofurantoin (at term) 3. Ciprofloxacin 4. Aminoglycosides

Question 40

For UTI in pregnant women, what is the duration of abx?

Answer 40

7 days: asymptomatic bacteriuria or cystitis | 14 days: pyelonephritis

Question 41

Are cultures needed for UTI in pregnant women?

Answer 41

Yes, cultures are required for clearance of infection

Question 42

What should we look at if a patient is not responding after 2-3 days or has persistently positive cultures?

Answer 42

- Bacterial resistance - obstruction - renal abscess: big load/inoculum, requires drainage

Question 43

What are adjunctive therapy options for urinary symptoms?

Answer 43

1. Phenazopyridine 100-200mg tds - avoid in G6PD deficiency - ADR: nausea, vomiting, orange-red discolouration 2. Urine alkalinization w/ Na or K citrate