Urinary Tract Infection

Question 1

What is a Urinary Tract Infection (UTI)?

Answer 1

Infection of urethra, bladder or kidney

Question 2

How does UTI most commonly occur?

Answer 2

Most commonly arises due to ascending infection

Question 3

What population has a higher incidence of UTIs?

Answer 3

Females

Question 4

What are the most common risk factors for UTIs?

Answer 4

Sexual intercourse, Urinary stasis (inc. risk for bacteria to grow in urine) and catheters.

Question 5

What is Cystitis?

Answer 5

Infection of the bladder

Question 6

What does Cystitis present with?

Answer 6

Dysuria (pain when urinating), urinary frequency, urgency and suprapubic pain

Question 7

What symptoms are usually absent with Cystitis?

Answer 7

Systemic signs (e.g. fever) are usually absent

Question 8

What are three important laboratory tests for UTI?

Answer 8

1. Urinalysis
2. Dipstick
3. Culture

Question 9

What does a Urinalysis show with UTI?

Answer 9

Cloudy urine with > 10 WBCs/high power field (hpf)

Question 10

What does a Dipstick test show with UTI?

Answer 10

Positive leukocyte esterase (due to pyuria) and nitrites (bacteria convert nitrates to nitrites)

Question 11

What does a Culture show with UTI?

Answer 11

Greater than 100,000 colony forming units (gold standard)

Question 12

What is the most common cause of UTIs? What percentage of UTIs does it represent?

Answer 12

E. coli, 80%

Question 13

What is the second most common cause of UTIs?

Answer 13

Staphylococcus saprophyticus

Question 14

In what age/group is Staphylococcus saprophyticus most common?

Answer 14

Increased incidence in young, sexually active women (but E. coli is still more common in this population)

Question 15

What is the third most common cause of UTIs?

Answer 15

Klebsiella pneumoniae

Question 16

What is the fourth most common cause of UTIs?

Answer 16

Proteus mirabilis

Question 17

What do you find in UTIs caused by proteus mirabilis?

Answer 17

Alkaline urine with ammonia scent

Question 18

What is the fifth most common cause of UTIs?

Answer 18

Enterococcus faecalis

Question 19

What is Sterile Pyuria?

Answer 19

Presence of pyuria (>10 WBCs/hpf and leukocyte esterase) with a negative urine culture.

Question 20

What is pyuria?

Answer 20

Presence of pus in the urine

Question 21

What does the finding of Sterile Pyuria suggest?

Answer 21

Urethritis due to Chlamydia trachomatis or Neisseria gonorrhoeae

Question 22

What is the dominant presenting sign of urethritis?

Answer 22

Dysuria

Question 23

What is Pyelonephritis?

Answer 23

Infection of the kidney

Question 24

What usually causes Pyelonephritis?

Answer 24

Usually due to ascending infection

Question 25

When is there an increased risk for Pyelonephritis?

Answer 25

With vesicoureteral reflux

Question 26

What does pyelonephritis present with?

Answer 26

Fever, flank pain, WBC casts, and leukocytosis in addition to symptoms of cystitis.

Question 27

What is the most common pathogen associated with Pyelonephritis?

Answer 27

E. coli (90%)

Question 28

What are the second and third most common pathogens associated with Pyelonephritis?

Answer 28

2. Enterococcus faecalis

3. Klebsiella species

Question 29

What is Chronic Pyelonephritis?

Answer 29

Interstitial fibrosis and atrophy of tubules due to multiple bouts of acute pyelonephritis.

Question 30

What causes Chronic Pyelonephritis?

Answer 30

Due to vesicoureteral reflux (children) or obstruction (e.g. BPH (benign prostatic hyperplasia) or cervical carcinoma)

Question 31

What is vesicoureteral reflux?

Answer 31

• Angle between bladder and ureter is malformed –>
• Inc. risk of reflux to kidney –>
• Inc. scarring

Question 32

What does Chronic Pyelonephritis lead to?

Answer 32

Cortical scarring with blunted calyces

Question 33

What type of scarring is characteristic of vesicoureteral reflux?

Answer 33

Scarring at the upper and lower poles is characteristic of vesicoureteral reflux

Question 34

What is seen in a histological slide of Chronic Pyelonephritis?

Answer 34

Atrophic tubules containing eosinophilic proteinaceous material –> they resemble thyroid follicles (‘thyroidization’ of the kidney)

Question 35

What can be seen in the urine of Chronic Pyelonephritis?

Answer 35

Waxy casts