Urinary Tract Infection

Question 1

What organism causes 70% of all UTIs?

Answer 1

Escherichia coli (gram negative, anaerobe) = 70%

Proteus spp (gram negative) = 12%

Staphylococcus saprophyticus / epidermis = 10%

Enterococcus faecalis = 6%

Pseudomonas spp = 5%

Klebsiella spp. = 4%

Question 2

What organisim causes 12% of all UTIs?

Answer 2

Proteus spp (gram negative) = 12%

Escherichia coli = 70%

Staphylococcus saprophyticus / epidermis = 10%

Enterococcus faecalis = 6%

Pseudomonas spp = 5%

Klebsiella spp = 4%

Question 3

How common is UTI?

Answer 3

1-2% presentations to GP is UTI

Question 4

Who does UTI affect?

Answer 4

Mainly women.

newborn males, older men due to prostate probs

Question 5

What are the symptoms of cystitis (lower UTI)?

Answer 5

• increased frequency
• urgency
• nocturia
• dysuria / burning
• Haematuria
• Suprapubic pain

Question 6

What are the symptoms of acute pyelonephritis?

Answer 6

• fever + rigors
• vomiting
• loin pain
• tenderness
• oliguria (in renal failure)

Question 7

What are the symptoms of prostitis?

Answer 7

• flu like
• backache
• swollen, tender prostate on PR
• few urinary symptoms

Question 8

How may UTIs present in elderly?

Answer 8

confusion

Question 9

What are the risk factors for UTI?

Answer 9

• female
• sex
• pregnancy
• menopause (low oestrogen makes it easier for bacteria to adhere)
• immunosuppression
• urinary tract obstruction from stones, stricture leads to statis so increased bacteria.
• long term catheters
• Diabetes

Question 10

How is a relapse of UTI diagnosed?

Answer 10

• recurrence of bacteriuria with same organism within 7 days of complete antibacterial treatment.

(failure to eradicate infection)

Question 11

What conditions are more likely to have a UTI relapse?

Answer 11

• Urinary tract stone
• scarred kidneys
• polycystic kidneys
• bacterial prostatitis

Question 12

What is the definition of a UTI reinfection?

Answer 12

When bacteriuria is absent after treatment for at least 14 days, then followed by recurrence of UTI. (reinvasion of urinary tract by infective organisms)

Question 13

What investigations are done for suspected UTI?

Answer 13

1) Urine Dipstick (If UTI shows +ve nitrites or +ve leucocytes)
2) Mid stream urine (if pt symptomatic but dipstick -ve. growth of >10^5organism/L is diagnostic of UTI

MSU Microscopy:

• WBC >3 = pyuria
• RBC > 2 = microscopic haematuria

3) Bloods
- FBC (raised WCC?)
- U&E (AKI?)
- CRP
- blood cultures (urosepsis?)
- fasting glucose (diabetes?)
- PSA (after 6 months for enlarged prostate)

3) USS for suspected pyelonephritis, stones, obstruction, incomplete emptying)

Question 14

Why is a routine urine dipstick done in pregnant patients?

Answer 14

In pregnancy UTIs are common and can be asymptomatic until they cause serious pyelonephritis —–> fetal death.

Question 15

What 4 organisms cause UTIs?

Answer 15

• E.coli
• Proteus Mirabilis
• Klebsiella pneumonia
• Staph saprophyticus

Question 16

UTIs can be class as complicated or uncomplicated - describe each.

Answer 16

Uncomplicated UTI = normal renal tract and function

Complicated = Abnormal renal / genitourinary tract, passing urine difficult/obstruction, decreased renal function, impaired host defence, virulent organisms e.g. staph aureus.)

Question 17

What is the treatment for a single isolated attack of UTI?

Answer 17

1) Abx for 3-5days with amoxicillin, nitrofurantoin, trimethoprim or an oral cephalosporin.

(if resistant to Abx give co-amoxiclav or ciprofloxacin)

2) drink plenty of fluid
3) If suspected pyelonephritis give IV aztreonam, cefuroxime, ciprofloaxacin or gentamicin) —-> then switch to oral abx.

Question 18

What is the treatment for relapse of UTI?

Answer 18

• find cause e.g. stone or scarred kidney and eradicate

Question 19

What is the treatment for reinfection of UTI?

Answer 19

prophylactic measurements:

• increased fluid intake (cranberry juice)
• passing urine every 2-3hrs, before sleep, after sex.
• avoid constipation (can impair bladder emptying)

Question 20

What are the causes of sterile pyuria?

Answer 20

TB
appendicitis
stones
bladder tumour