|  | Conditions & Treatments | Infectious Diseases

Understanding Cholera: Types, Causes, and Symptoms

Cholera is an acute secretory diarrheal illness caused by Vibrio cholerae serogroups O1 and O139.

Biotypes of V. cholerae O1

  • Classical: Historic pandemics (1–6); more severe; produces cholera toxin (CT) only.
  • El Tor: Current 7th pandemic (since 1961); milder, longer survival in environment, asymptomatic carriers common; produces CT + hemolysin.

O139 (Bengal) emerged 1992; similar to El Tor, capsule-positive.

Transmission

Fecal-oral: contaminated water/food (shellfish, raw vegetables). Direct person-to-person rare.

Pathogenesis

CT binds GM1 ganglioside → activates adenylate cyclase → ↑cAMP → CFTR Cl⁻ secretion + inhibited Na⁺ absorption → massive isotonic fluid loss (up to 1 L/hr).

Clinical Presentation

  • Rice-water stools: Watery, flecked with mucus, fishy odor.
  • Vomiting: Early, profuse.
  • Dehydration: Rapid, severe (sunken eyes, poor skin turgor, hypotension, anuria).
  • Electrolytes: Hypokalemia, hypocalcemia, metabolic acidosis.

Treatment

  1. ORS (WHO reduced-osmolarity): 75 mL/kg first 4 hrs, then maintenance + losses.
  2. IV fluids (Ringer's lactate): Severe dehydration, shock, vomiting.
  3. Antibiotics (adjunct): Doxycycline, azithromycin, ciprofloxacin → reduce volume/duration by 50%.
  4. Zinc (children): 20 mg/day × 10 days.

Prevention

  • Safe water, sanitation, hygiene (WASH).
  • Oral cholera vaccines (killed whole-cell): Shanchol, Euvichol (2 doses, 3-year protection).

Infectious Diseases - Related Articles