Urinary Tract Infection

Question 1

How common is it?

Answer 1

Very common – half of all women in a year, and 1 in 2000 healthy men in a year.

Question 2

Who does it affect?

Answer 2

Mainly women, rarer in men due to longer urinary tract.

Question 3

What causes it?

Answer 3

• E. coli is main organism (75-95% in community but >41% in hospital.)
• Occasionally other enterobacteriaceae such as Proteus mirabilis and Klebsiella pneumonia, and other bacteria such as Staphylococcus saprophyticus.

Question 4

Risk factors?

Answer 4

• Females at greater risk than males.
• Sexual intercourse
• Exposure to spermicide in ♀ (by diaphragm or condoms)
• Pregnancy or menopause
• ↓Host defence (immunosuppression, DM)
• Urinary tract: obstruction, stones, catheter, malformation.

Question 5

How does it present?

Answer 5

Symptoms

• Acute pyelonephritis – high fever, rigors, vomiting, loin pain and tenderness, oliguria (if acute kidney injury)
• Cystitis – frequency, dysuria, urgency, haematuria, suprapubic pain.
• Prostatitis – flu-like symptoms, low backache, few urinary symptoms, swollen or tender prostate on PR.

Signs
- Fever, abdominal or loin tenderness, foul smelling urine. Occasionally distended bladder, enlarged prostate.

Question 6

Conditions with similar presentations?

Answer 6

• Other causes of sterile pyuria – treated UTI <2 weeks prior; inadequately treated UTI; appendicitis; calculi; prostatitis; bladder tumour; UTI with fastidious culture requirement; papillary necrosis; polycystic kidney; chemical cystitis. - Similar symptoms in: urethral syndrome; atrophic vaginitis; gential infections with candida albicans, herpes simplex,Chlamydia trachomatis and Gardnerella spp; enlarged or inflamed prostate in men.

Question 7

Investigations?

Answer 7

• If symptoms present, dipstick urine.; treat empirically if nitrites or cocytes are +ve.
• If dipstick –ve but patient symptomatic, send an MSU for lab MC&S to confirm. Send a lab MSU anyway If male, a child, pregnant, immunosuppressed or ill.

Blood tests – FBC, U&E, CRP and blood culturesif systemically unwell (urosepsis). Consider fasting glucose and PSA (wait 6 months, as UTI causes false +ves).

Imaging – Consider USS and referral to urology for assessment (CTKUB, cytoscopy, urodynamics) for UTI in children, men, if failure to respond to treatment, recurrent UTI, pyelonephritis, unusual organism, persistent haematuria.

Question 8

Treatments?

Answer 8

• Drinking plenty of fluids and urinating often.
• Consider empirical treatment for presumed E.coli in otherwise healthy women who present with lower UTI: trimethoprim or nitrofurantroin, amoxicillin. Alternative = cefalexin, co-amoxiclav.
• In pregnant women get expert help.
• In men, take seriously as often arises from anatomical or functional abnormality -> refer to urologist.