Urinary tract infections

• Recurrent bacterial cystitis is defined as two or more UTIs in 6 months or 3 or more UTIs in 12 months
• Common pathogens:

  • Most common = Uropathogenic Escherichia Coli
  • Klebsiella pneumoniae
  • Enterococcus faecalis - mostly hospital acquired
  • Candida albicans - fungal
• When to do urine MC&S

  • Pregnant women
  • Men
  • Recurrent UTIs
  • Atypical symptoms
  • When symptoms persist after antibiotics
• Antibiotics (non pregnant women):

  1. Nitrofurantoin for 3 days or trimethoprim for 3 days
  2. Nitrofurantoin if not previously used
• Nitrofurantoin is contradicted if eGFR <45
• Antibiotics for UTI in men:

  1. Nitrofurantoin or trimethoprim for 7 days
  2. Consider alternative diagnosis or treat for pyelonephritis
• Antibiotics for UTI in pregnant women:

  • Nitrofurantoin for 7 days - avoid in third trimester
  • Amoxicillin for cefalexin for 7 days
• Trimethoprim is contraindicated in pregnancy
• ·        3 days of antibiotics for simple lower urinary tract infections in women

  ·        5-10 days of antibiotics for immunosuppressed women, abnormal anatomy or impaired kidney function

  ·        7 days of antibiotics for men, pregnant women or catheter-related UTIs
• Females are 30 times more likely than males to develop a UTI due to the shorter urethra. As a result, there is a greater probability of bacteria reaching the bladder before being expelled in urine, as the space between the opening of the urethra and the bladder is shorter
• For females, risk factors to consider include:

  • Sexual activity
  • Pregnancy
  • Incontinence
  • Post-menopause: absence of oestrogen (consistent with vaginal atrophy, also known as genitourinary syndrome of menopause)
  • Presence of a cystocele
  • Positive family history of UTIs
• For males, risk factors to consider include:

  • Benign prostatic hypertrophy
  • Urethral strictures
• In both sexes, the following are risk factors:

  • Previous history of UTI
  • Presence of a foreign body: any indwelling catheter or foreign body (e.g. stone, suture, surgical material, or exposed polypropylene mesh from pelvic surgery) significantly increases the risk for UTI
  • Diabetes mellitus
• Typical symptoms of lower and uncomplicated UTIs (cystitis) include:

  • Dysuria: feeling of pain, discomfort or burning sensation while urinating
  • Urgency: an unstoppable urge to urinate due to sudden involuntary contraction of the bladder muscles
  • Frequency: urinating too often and at frequent intervals
  • Hesitancy: inability to start the urine stream
  • Suprapubic pain
  • New-onset nocturia: waking during the night to urinate
  • New-onset urinary incontinence: loss of bladder control
  • Haematuria: blood in the urine
• Typical clinical findings in UTI include:

  • Suprapubic tenderness
  • Costovertebral tenderness, if kidney involvement (pyelonephritis)
• Relevant bedside investigations include:

  • Basic observations: to assess for systemic features (e.g. fever/tachycardia) which may suggest pyelonephritis
  • Urinalysis: to assess for the presence of nitrites, leukocyte esterases, protein, and haematuria.
  • Urine pregnancy test (hCG urine dipstick): to rule pregnancy in or out. This investigation is relevant, as UTIs are common in pregnant women, and pregnancy will influence management, including antibiotic options.
• The following findings would be diagnostic on urinalysis:

  • Nitrites: strongly suggestive of bacteriuria, as nitrates are broken down into nitrites only in the presence of bacteria.
  • Leukocyte esterases: an enzyme leukocytes produce in response to bacteria in the urine.
• Most UTIs will spontaneously resolve in about 20% of females, especially with increased hydration.
• NICE guidelines recommend checking any previous urine cultures, susceptibility results and antibiotic prescribing before choosing an antibiotic.