Urinary tract infection

Definition

• UTI: Infection that affects part of the urinary tract.
• Lower UTI (cystitis): Affects the bladder.
• Upper UTI (pyelonephritis): Affects the kidneys.

Epidemiology

• More common in females due to shorter urethra.
• Faecal incontinence (colonisation by faecal flora)
• Occurs at all ages but increased incidence in the elderly and sexually active females.

Causes

• Escherichia coli (E. coli): Most common pathogen.
• Staphylococcus saprophyticus, Proteus mirabilis, Klebsiella, Enterococcus spp. among others.
• Risk factors: Catheterisation, pregnancy, diabetes, urinary stasis, sexual activity, postmenopausal status in women.

Clinical Presentation

• Lower UTI: Dysuria, frequency, urgency, hematuria, cloudy urine, suprapubic pain.
• Upper UTI: Flank pain, fever, chills, nausea, vomiting, malaise in addition to symptoms of lower UTI.

Investigations

• Urine dipstick: Nitrates, leukocyte esterase.
• Urine microscopy & culture: To identify pathogen and its sensitivities.
• Ultrasound or CT if structural abnormalities are suspected or recurrent infections.

Management

• Lower UTI: Short course (3 days) of antibiotics like Nitrofurantoin, Trimethoprim or Amoxicillin.
• Upper UTI: Oral or IV antibiotics such as Co-amoxiclav or Ciprofloxacin, depending on severity. Typically, a longer course (7-14 days).
• Address underlying risk factors and causes.
• Adequate fluid intake.

Complications

• Sepsis.
• Renal abscess.
• Recurrent infections.
• Renal scarring and impairment.