Diagnosis

Urinary tract infection

Etiology

Cause [feo]

• Bacteria:

  Escherichia coli, Staphylococcus saprophyticus, Klebsiella, Enterococcus faecalis, Staphylococcus aureus, Brucellosis, Citrobacter, Proteus, Pseudomonas, Schistosomiasis

Risk factor [feo]

• Trauma

• Catheter

• Surgery

• Urinary retention or bladder diverticulum/fistula

• Cystocele

• Dehydration

• Diabetes

• Diarrhea

• Sexual intercourse

• Pregnancy

Pathophysiology [feo][1sn]

1. Enteric bacteria, which normally inhabit the periurethral vaginal introitus, ascend the urethra into the bladder and trigger an inflammatory reaction --> cystitis

2. The shorter female urinary tract is inherently predisposed to bacterial seeding and proximal spread

3. Urine has natural antimicrobial properties (pH < 5, high urea levels, hyperosmolality, organic acids, proteins, and nitrites)

4. Frequent urination and high urinary volumes also reduce the risk of UTI

5. Clinical presentation:

   • Dysuria

   • Urinary frequency, hesitancy and urgency

   • Suprapubic pain (bladder spasms)

   • Hematuria

   • Urinary odor

6. Complicated UTI: fever, chills, nausea, vomiting, back/flank pain, stones, sepsis, urinary obstruction, catheters (biofilm), or involving the kidneys, immunocompromised patients, males, pregnant patients

Complications [feo]

• Pyelonephritis

• Urosepsis

• Urine retention

• Prostatitis

• Incontinence

• Renal abscess

• Renal failure

Epidemiology

Incidence per 100.000 [p1g][uis]

Approach

• Blood test

• Urine stix: alkaline urine, bacteria converting nitrates into nitrites, WBC, hematuria

• Urine culture: synptomatic patient + ≥1000 CFU/mL = diagnostic for a UTI [feo]

Treatment

1. Antibiotics: 3-7 days for women and >7 days for men [feo]

   1st line: nitrofurantoin, trimethoprim/sulfamethoxazole, trimethoprim alone, fosfomycin, 1st gen cephalosporins, and pivmecillinam

2. Adjunctive therapies of variable evidence:

   • Cranberry (juice, pills, or extract)

   • D-mannose

   • Estrogen vaginal cream

   • Increased fluid intake is helpful

3. Complicated UTI: Antibiotics for 10-14 days

   • Remove or replace catheter: Most antibiotics cannot effectively penetrate biofilms

   • Urinary retention/hydronephrosis --> JJ-stent or stone extraction

   • Perinephric abscess --> drainage

   • Initial broad-spectrum options: Penicillins, cephalosporins, and carbapenems

Differential diagnoses

Bladder cancer, Chlamydia, Gonorrhea, Herpes simplex, Interstitial cystitis, Overactive bladder, Pelvic inflammatory disease, Prostatitis, Pyelonephritis, Renal infarction, Renal thrombosis, Urolithiasis, Urosepsis, Vaginitis