Urinary Tract Infections Quiz

Urinary Tract Infections (UTIs)

• UTIs are the presence of pathogenic microorganisms in the genitourinary tract, with associated signs and symptoms of infection.
• UTIs present as a variety of syndromes, based on location in the urinary tract, including acute cystitis, pyelonephritis, and prostatitis.
• Pathogens can invade urinary tract tissues and adjacent structures, or be limited to bacterial growth in the urine, sometimes without symptoms.
• UTIs can range from asymptomatic bacteriuria to pyelonephritis with bacteremia or sepsis.
• Bacteria often colonize the female urethra due to its shorter length and proximity to the perirectal area.
• Pyelonephritis (infection of one or both kidneys) is sometimes classified as a subset of complicated UTIs if caused by functional/structural abnormalities.
• Common bacterial pathogens causing complicated UTIs include Enterobacteriaceae and other Gram-negative bacteria, and Gram-positive bacteria like enterococci.
• Escherichia coli is the most common cause of uncomplicated UTIs.
• UTIs account for 8 million patient visits annually.
• Approximately one in three females will have a UTI by age 24.
• UTIs in males are less common until age 65.

Risk Factors

• Men:
  • Intercourse with an infected woman
  • Prostate hyperplasia
• Women:
  • Sexual intercourse
  • Lack of voiding after intercourse
  • Use of a diaphragm contraceptive
  • Pregnancy
• Both men and women:
  • Diabetes Mellitus (DM)
  • Urologic instrumentation
  • Renal transplantation
  • Neurogenic bladder
  • Urinary tract obstruction

Clinical Presentation

• Lower UTI (Cystitis):
  • Dysuria, urgency, frequency, nocturia, suprapubic heaviness, suprapubic tenderness on examination, and gross hematuria.
• Upper UTI (Pyelonephritis):
  • Flank pain, fever, nausea, vomiting, costovertebral tenderness, malaise.
• Laboratory Tests:
  • Bacteriuria
  • Pyuria (WBC count >10/mm3)
  • Nitrite positive urine (with nitrite reducers)
  • Leukocyte esterase positive urine
  • Antibody-coated bacteria (upper UTI)

Bacteriuria

• Bacteriuria (bacteria in the urine) doesn't always indicate infection.
• Quantitative criteria are used to diagnose significant bacteriuria, identifying the amount of bacteria potentially signifying infection.
• Asymptomatic bacteriuria (ASB) is significant bacteriuria (>105 bacteria/mL of urine) in two consecutive urine cultures, in the absence of symptoms, commonly seen in those above 65 years of age.
• Symptomatic bacteriuria or acute urethral syndrome involves frequency and dysuria without significant bacteriuria; sometimes associated with Chlamydia infections.

Principles of Treatment

• Goals: Eradicate the organism, prevent/treat consequences, prevent recurrence.
• Reinfection: Recurrence due to a new organism.
• Relapse: Recurrence due to the same organism (suggests persistent infectious source).
• Management: Initial evaluation, selection of antibacterial agent, duration of therapy, and follow-up evaluation.
• Considerations include antibiotic susceptibility, side effects, cost, previous antimicrobial exposure, and treatment convenience.
• Empirical antibiotic therapy, considering local resistance patterns to minimize treatment failure chances.
• Antimicrobial treatment should be well-tolerated, narrow spectrum, patient-friendly, reach the infection site effectively, and be orally bioavailable.
• Adjunctive therapies (e.g., phenazopyridine for severe dysuria).

Pharmacological Therapy

• Antimicrobial therapy (empirical) is the cornerstone of treatment in UTIs.
• Ideal characteristics include well-tolerated, narrow spectrum, patient-friendly, effective site-of-infection concentration, and good oral bioavailability.

Evidence-Based Empirical Treatment

• Specific treatments (antibiotics) and durations are presented for various diagnoses and populations (e.g. acute uncomplicated cystitis, acute uncomplicated pyelonephritis, pregnancy).

UTI in Pregnancy

• Pregnancy increases UTI risk due to physiologic changes (hormonal, mechanical).
• Increased risk of acute pyelonephritis, preterm birth, and stillbirth.
• Pregnant women should be screened for bacteriuria (urine culture).
• Appropriate, and sometimes different antibiotic treatments are discussed for pregnant individuals.

Catheterized Patients

• Indwelling catheters are common and associated with UTIs via catheterization or bacterial motility.
• Screening, prophylactic and treatment of UTIs in catheterization patients is discussed

Post-exposure Prophylaxis

• Reinfection is sometimes associated with sexual intercourse.
• Treatment with single doses of trimethoprim-sulfamethoxazole or nitrofurantoin after sexual activity may help prevent reinfection.

Cystitis in Men

• Asymptomatic and symptomatic UTIs are less common in men than women due to anatomical differences.
• Most men with UTI should be treated as a complicated infection with possible complications.
• Treatment and considerations are discussed for specific cases, including but not limited to males with complicated infections.