Cholera

Disease Description (Causes and Symptoms)

• Definition summary: Cholera is an acute intestinal infection caused by infection with Vibrio cholerae (the cholera bacterium), which can cause rapid dehydration through severe watery diarrhea (resembling rice water) and vomiting. It is seasonally common in summer.
• Cause: Primarily oral ingestion of contaminated drinking water or food (especially coastal shellfish), transmission through contaminated hands, and transmission through the vomit or feces of an infected patient. When gastric acid is low (such as after gastrectomy or in achlorhydria), infection can occur with a small number of bacteria.
• Pathophysiology (brief): Cholera toxin (CT) produced by Vibrio cholerae activates Gs proteins in small-intestinal epithelial cells, increasing intracellular cAMP levels → a sharp increase in enterotoxigenic water and electrolyte secretion into the small intestine → massive watery diarrhea.
• Main symptoms: Sudden, large-volume watery diarrhea (white, cloudy, rice-water-like stool), vomiting, relatively mild abdominal pain, and rapid dehydration (dry mouth, orthostatic hypotension, anuria). In severe cases, shock and impaired consciousness may occur; fever is usually mild or may be absent.
• Risk of complications: Acute kidney injury (due to dehydration), metabolic acidosis, shock, electrolyte abnormalities (such as hypokalemia), and death (high fatality rate if untreated).

Treatment

• Basic principle: Rapid fluid replacement to restore fluid and electrolyte status is the highest priority. Antibiotics play an adjunctive role and may shorten the duration of diarrhea and the period of bacterial shedding.
• Fluid therapy
  • Mild to moderate: Oral rehydration therapy (ORS) is preferred when vomiting is not severe and the patient can swallow.
  • Severe dehydration, persistent vomiting, or signs of shock: Administer intravenous fluids (such as normal saline or lactated Ringer's solution) immediately and adjust the infusion rate as needed (the response must be monitored).
  • Electrolyte correction: Monitor and replace electrolytes such as potassium. Check kidney function and acid-base status.
• Antibiotics: Determined according to local resistance patterns and the patient's condition. Antibiotics may shorten the duration of symptoms and reduce bacterial shedding, but fluid therapy is most important. (The specific drug and dosage should be determined by the treating physician.)
• Hospitalization and monitoring: Hospitalization and intensive monitoring are necessary for patients with severe disease or suspected kidney failure, electrolyte abnormalities, or persistent shock.
• Infection control and public health: Reporting is required as a legally designated infectious disease (as designated by each country); follow the guidance of the relevant public health authorities. Apply standard and contact precautions when handling the patient's feces or vomit. Handwashing and hygiene management are essential.
• Lifestyle management and precautions
  • Rapid fluid replacement and the use of ORS containing salt and sugar are recommended.
  • Do not delay self-care when dehydrated: If symptoms are severe, visit a medical institution immediately.
  • Take antibiotics as prescribed by a physician; indiscriminate antibiotic use may cause antibiotic resistance.
  • Maintain strict food and water hygiene (boiled water, thoroughly cooked food, and hand hygiene).
  • Prognosis: With appropriate treatment, the fatality rate is very low (1% or less according to WHO data and other sources). Without treatment, the fatality rate is very high (tens of percent, depending on the source).

Checklist Before an Outpatient Visit (Including Items to Bring and Example Questions)

• Items/data to bring
  • List of medications currently being taken (especially anti-inflammatory drugs, antacids, antibiotics, diuretics, etc.)
  • Recent changes in body weight and records of urine volume, if possible
  • Time diarrhea and vomiting began, number of episodes of diarrhea and the amount and color of stool (including whether it resembles rice water), number of vomiting episodes, and presence or absence of fever
  • Recent travel history (overseas travel, especially to areas with poor sanitation) and possible exposure to contaminated food or water (such as eating fish or shellfish)
  • Whether similar symptoms have occurred among household members or people nearby
  • Medical history of previous gastrectomy or reduced gastric acid secretion (achlorhydria)
  • Recent test results, if available — electrolyte, kidney function, and stool test results
• Examples of key questions to record for the outpatient visit (prepare in advance)
  • When did the diarrhea begin? How many times a day does it occur?
  • How has the amount and color of your urine changed over the past few days?
  • Have you recently traveled overseas or eaten contaminated food?
  • Are you taking any existing medications, or do you have any underlying conditions (especially stomach surgery or liver or kidney disease)?

General Examples of Questions to Ask the Doctor

• "How will you assess the severity of my dehydration? Do I need hospitalization or intravenous fluids?"
• "What type of fluid and infusion rate are recommended?"
• "Do I need antibiotics? If so, which medication should I take and for how long?"
• "How will electrolyte correction and kidney function be managed?"
• "What should I be careful about when managing my condition at home?"

Examples of Disease-Specific Questions

• "I recently took antacids (or have a history of gastrectomy). Could this have increased my susceptibility to infection?"
• "What isolation and hygiene measures should be taken to prevent infection among family members and household members, and for how long?"

(Note: Diagnosis is made by combining stool culture/detection results with clinical findings. Because management and treatment may vary according to local public health guidelines and antibiotic resistance patterns, it is important to follow the guidance of local medical professionals.)