Lower Urinary Tract Infections (UTIs)

Overview

• Lower UTI: Infection in the bladder, causing cystitis (inflammation of the bladder).
• Potential Spread: Can lead to pyelonephritis (infection and inflammation of the kidneys).
• Prevalence: More common in women due to shorter urethra.

Causes

• Primary Source: Bacteria from feces, particularly E. coli.
• Contributors:
  • Sexual activity.
  • Incontinence and poor hygiene.
  • Urinary catheters (often more challenging to treat).

Symptoms

• Typical Symptoms:
  • Dysuria (pain, stinging, or burning during urination).
  • Suprapubic pain or discomfort.
  • Urinary frequency and urgency.
  • Incontinence and hematuria (blood in urine).
  • Cloudy or foul-smelling urine.
  • Confusion, particularly in older or frail patients.

Pyelonephritis

• Symptoms to Differentiate:
  • Fever, loin or back pain.
  • Nausea or vomiting.
  • Renal angle tenderness on examination.

Diagnostic Testing

• Urine Dipstick Tests:
  • Nitrites: Indicate bacteria presence (E. coli converts nitrates to nitrites).
  • Leukocytes: Indicate white blood cells and inflammation.
  • Hematuria: Blood presence (microscopic or macroscopic).
  • Nitrites + Leukocytes: Strong indicator of UTI.
  • Only Leukocytes: Not treated as UTI without clinical evidence.
• Midstream Urine (MSU) Sample:
  • Sent for microscopy, culture, and sensitivity testing.
  • Important for pregnant women, recurrent UTIs, atypical symptoms, or no improvement with antibiotics.

Pathogens

• Common Bacteria:
  • Escherichia coli (E. coli) - most common.
  • Klebsiella pneumoniae.
  • Enterococcus species.
  • Pseudomonas aeruginosa.
  • Staphylococcus saprophyticus.
  • Fungal cause: Candida albicans.

Treatment

• Antibiotic Choice:
  • Follow local guidelines.
  • Trimethoprim: Common but high resistance.
  • Nitrofurantoin: Avoid in renal impairment (eGFR < 45).
  • Alternatives: Pivmecillinam, Amoxicillin, Cephalexin.

UTIs in Pregnancy

• Risks:
  • Increased risk of pyelonephritis, premature rupture of membranes, and preterm labor.
• Treatment:
  • Seven days of antibiotics.
  • Antibiotic Options:
    • Nitrofurantoin (avoid in the third trimester).
    • Amoxicillin (post-sensitivity testing).
    • Cephalexin.
• Trimethoprim: Avoid in the first trimester due to risk of congenital malformations (e.g., neural tube defects).

Resources

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