UTI

Question 1

Define urinary tract infection

Answer 1

the presence of a pure growth of > 105 organisms per mL of fresh MSU

Question 2

Sub-Classification

Answer 2

Lower UTI - affecting the urethra (urethritis), bladder (cystitis) or prostate (prostatitis)

Upper UTI - affecting the renal pelvis (pyelonephritis)

NOTE: the laboratory classification mentioned above isn’t a complete necessity for the diagnosis of UTI - 1/3 women with symptoms of UTI will have negative MSU

Question 3

Other Classification

Answer 3

Uncomplicated UTI - normal renal tract and function

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

Question 4

Explain the aetiology

Answer 4

MOST UTIs are caused by Escherichia coli

Other causative organisms:

Staphylococcus saprophyticus

Proteus mirabilis

Enterococci

Atypical organisms that can cause UTI (usually in immunocompromised individuals):

Klebsiella

Candida albicans

Pseudomonas aeruginosa

Question 5

Risk Factors

Answer 5

FEMALE

Sexual intercourse

Exposure to spermicide

Pregnancy

Menopause

Immunosuppression

Catheterisation

Urinary tract obstruction

Urinary tract malformation

Question 6

Summarise the epidemiology of urinary tract infections

Answer 6

VERY COMMON

1-3% of GP consultations

The majority of women will have a UTI in their lifetime

MUCH more common in FEMALES

Question 7

Presenting Symptoms: Cystitis

Answer 7

Frequency

Urgency

Dysuria

Haematuria

Suprapubic pain

Question 8

Presenting Symptoms: Prostatitis

Answer 8

Flu-like symptoms

Low backache

Few urinary symptoms

Swollen or tender prostate on PR

Question 9

Presenting Symptoms: Acute Pyelonephritis

Answer 9

High fever

Rigors

Vomiting

Loin pain and tenderness

Oliguria (if AKI)

Question 10

Recognise the signs of urinary tract infection on physical examination

Answer 10

Fever

Abdominal or loin tenderness

Foul-smelling urine

Distended bladder (occasionally)

Enlarged prostate (if prostatitis)

Question 11

Identify appropriate investigations for urinary tract infection

Answer 11

Urine Dipstick: Positive leucocyte esterase and nitrites

Urine Microscopy: Presence of leucocytes indicates infection

Urine Culture: To exclude diagnosis or if the patient failed to respond to empirical antibiotics

Ultrasound: Rule out obstruction

Bloods

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

Question 12

Generate a management plan for urinary tract infection

Answer 12

Empirical treatment of uncomplicated UTI: TRIMETHOPRIN or NITROFURANTOIN

Treat for 3-6 days

NOTE: men with UTI may need a longer course of antibiotics

Alternative Treatments: Co-amoxiclav or Cefalexin

Prophylactic antibiotics may be used in certain circumstances (e.g. recurrent cystitis associated with sexual intercourse)

Question 13

Identify possible complications of urinary tract infection

Answer 13

Ascending infection can lead to:

Pyelonephritis

Perinephric and intrarenal abscess

Hydronephrosis or pyonephrosis

AKI

Sepsis

Prostatic involvement (e.g. prostatitis) in men with UTIs is common

Question 14

Summarise the prognosis for urinary tract infection

Answer 14

GOOD prognosis with appropriate treatment