Urinary tract infection

Question 1

Define urinary tract infection

Answer 1

Presence of a pure growth of >10^5 organisms per ml of fresh MSU

Question 2

Classification of urinary tract infection

2 types

Answer 2

Lower UTI - affecting urethra (urethritis), bladder (cystitis) or prostate (prostatitis)
Upper UTI - affecting renal pelvis (pyelonephritis)

Uncomplicated UTI - normal renal tract & function
Complicated UTI - abnormal renal/genitourinary tract, voiding difficulty/obstruction, reduced renal function, impaired host defences, virulent organism (e.g. S. aureus)

Question 3

Causes of urinary tract infection

1 + 3 others

Answer 3

ESCHERICHIA COLI

Other causative organisms:
Staphylococcus saprophyticus
Proteus mirabilis
Enterococci

Question 4

Risk factors for urinary tract infection

9

Answer 4

FEMALE
Sexual intercourse
Exposure to spermicide
Pregnancy
Menopause
Immunosuppression
Catheterisation
Urinary tract obstruction 
Urinary tract malformation

Question 5

Epidemiology of urinary tract infection

2 prevalence, gender

Answer 5

VERY COMMON

1-3% GP consultations
Much more common in females

Question 6

Presenting symptoms of urinary tract infection divided into…
(3)

Answer 6

Cystitis
Prostatitis
Acute pyelonephritis

Question 7

Presenting symptoms of urinary tract infection - cystitis

5

Answer 7

Frequency
Urgency
Dysuria
Haematuria
Suprapubic pain

Question 8

Presenting symptoms of urinary tract infection - prostatitis
(4)

Answer 8

Flu like symptoms
Low backache
Few urinary symptoms
Swollen or tender prostate on PR

Question 9

Presenting symptoms of urinary tract infection - acute pyelonephritis
(5)

Answer 9

High fever
Rigors
Vomiting
Loin pain & tenderness
Oliguria (if AKI)

Question 10

Signs of urinary tract infection on physical examination

5

Answer 10

Fever
Abdominal or loin tenderness
Foul smelling urine
Distended bladder (occasionally)
Enlarged prostate (if prostatitis)

Question 11

Investigations for urinary tract infection

5

Answer 11

Urine dipstick
Urine microscopy
Urine culture
US
Bloods

Question 12

Investigations for urinary tract infection - urine dipstick

Answer 12

Positive leucocyte esterase & nitrites

Question 13

Investigations for urinary tract infection - urine microscopy

Answer 13

Presence of leucocytes indicates infection

Question 14

Investigations for urinary tract infection - urine culture

Answer 14

To exclude diagnosis or if patient failed to respond to empirical antibiotics

Question 15

Investigations for urinary tract infection - US

Answer 15

Rule out obstruction

Question 16

Investigations for urinary tract infection - bloods

4

Answer 16

FBC
U&Es - check renal function
CRP
Blood cultures - if systemically unwell & risk of urosepsis

Question 17

Management of urinary tract infection

1 or 1 + 3 alt

Answer 17

Empirical treatment for uncomplicated UTI -TRIMETHOPRIM or NITROFURANTOIN for 3-6 days

Alternatives:
Co-amoxiclav
Cefalexin
Prophylactic antibiotics in certain circumstances

Question 18

Complications of urinary tract infection

6

Answer 18

Ascending infection can lead to 
Pyelonephritis
Perinephric & infrarenal abscess
Hydronephrosis or pyelonephritis
AKI
Sepsis
Prostatic involvement (prostatitis) common in men w/ UTIs

Question 19

Prognosis of urinary tract infection

Answer 19

GOOD prognosis w/ appropriate treatment