(GP) (Infection)

Overview

• Infection of the bladder, urethra, ureters or kidneys that are most commonly caused by bacteria, especially E. coli (gram negative bacilli)
• Bladder & Urethra are lower UTI’s, Kidneys & Ureters are upper UTI’s
• F>M → women have shorter urethra (hence shorter distance to bladder from urethral opening) and anal and genital regions that are closer in proximity, hence at higher risk of contracting UTI
• Risk Factors → abnormalities of urinary tract (BPH, Kidney Stones etc.), pregnancy, postmenopause, sexual intercourse, urinary catheters, anything causing urine stasis

Making Diagnosis

Clinical Features:

• Lower UTI (eg. urethritis, cystitis) → dysuria, urinary frequency + urgency, malodorous urine, haematuria, suprapubic tenderness (lower abdo pain)

• Upper UTI → symptoms of Lower UTI, fever, fatigue, flank pain, N&V (may have pyelonephritis)

• Acute Pyelonephritis (typically caused by ascending infection but may also be due to sepsis)

  • Flank (loin) pain + fever
  • Rigors and Vomiting
  • White Cell Casts in urine
  • May lead to haemodynamic instability

  Distinguishing features from cystitis ⇒ pyrexia, flank/loin pain + tenderness, abnormal vital signs

• Elderly patients may have delirium or acute confusion

Investigations:

• Urine Dipstick → 1st line, most important initial diagnostic test. Findings include positive leukocytes and nitrites.
• MSU should be sent for MC&S (microscopy, culture and sensitivities) → gold standard. Identify bacteria.
  • Pyelonephritis → will have white cell casts
  • Urine Culture → determine causative pathogen & adapt antibiotic treatment. E.coli is intesely pink on MacConkey agar (positive lactose fermentation).