What is cholera?

Cholera is an acute infectious disease caused by ingestion of water or food contaminated with the bacterium Vibrio cholerae. It affects the small intestine and leads to sudden onset of watery diarrhea. Without prompt treatment, cholera can cause severe dehydration and electrolyte loss, which may become fatal within hours in severe cases. Cholera primarily occurs in areas with limited access to clean water, sanitation, and healthcare.

The bacteria: Vibrio cholerae

Vibrio cholerae is a gram-negative bacterium that produces cholera toxin, which triggers massive fluid secretion in the intestines. Only certain strains, especially serogroups O1 and O139, cause epidemic cholera. The organism thrives in warm, brackish water and can attach to plankton, shellfish, and aquatic environments.

How does cholera spread?

Cholera spreads primarily through the fecal–oral route. Transmission occurs when people consume water or food contaminated with feces from an infected person. Common sources include:

• Contaminated drinking water: The most significant risk factor during outbreaks.
• Contaminated food: Raw or undercooked seafood, street-vended foods, and produce washed in unsafe water.
• Poor sanitation systems: Sewage leaking into drinking water supplies.
• Household transmission: Through contaminated hands, utensils, or surfaces.

Cholera does not spread through casual person-to-person contact. Large outbreaks typically occur where water systems are compromised by natural disasters, conflict, overcrowding, poverty, or infrastructure breakdown.

Signs and symptoms

Cholera symptoms range from mild to severe. Up to 80% of infected people may have mild or no symptoms, but they can still shed the bacteria.

Mild to moderate symptoms

• Watery diarrhea
• Abdominal discomfort or cramping
• Nausea or vomiting
• Mild dehydration

Severe cholera symptoms

• Profuse watery diarrhea, often described as “rice water” stools
• Projectile vomiting
• Rapid heart rate
• Dry mouth, extreme thirst
• Sunken eyes
• Muscle cramps due to electrolyte loss
• Severe dehydration and shock

Complications

Cholera’s most serious complication is severe dehydration, followed by:

• Hypovolemic shock
• Electrolyte imbalances, including dangerous drops in potassium or bicarbonate
• Acute kidney injury
• Seizures (more common in children with electrolyte loss)

How is cholera diagnosed?

Diagnosis is based on clinical features and laboratory confirmation:

• Clinical diagnosis: In outbreaks, watery diarrhea with rapid dehydration strongly suggests cholera.
• Stool culture: Definitive test to identify Vibrio cholerae.
• Rapid diagnostic tests (RDTs): Useful in low-resource settings.
• PCR testing: Detects bacterial DNA and is highly sensitive.

Treatment options

Cholera is highly treatable when addressed promptly. The goal is to rapidly replace lost fluids and electrolytes.

1. Oral Rehydration Solution (ORS)

ORS is the cornerstone of cholera treatment. It contains a precise balance of salts and glucose that enhances absorption in the intestines.

2. IV fluids

Severe dehydration requires immediate intravenous fluids. Ringer’s lactate is preferred due to its electrolyte composition.

3. Antibiotics

Antibiotics are not required for all patients but may reduce the duration and volume of diarrhea. Common choices include:

• Doxycycline
• Azithromycin
• Ciprofloxacin

Antibiotic selection depends on local resistance patterns.

4. Zinc supplementation

Zinc is recommended for children with cholera to reduce the length and severity of diarrhea.

Cholera prevention

Effective prevention requires a combination of community and individual measures:

• Safe drinking water: Boiling, chlorination, filtration, or use of safe bottled water.
• Improved sanitation: Proper waste disposal and sewage systems.
• Good hygiene: Handwashing with soap before eating and after bathroom use.
• Safe food practices: Eating thoroughly cooked foods, avoiding raw seafood, and washing produce with clean water.
• Oral cholera vaccines (OCVs): Effective for people in high-risk areas or during outbreaks.

Cholera and outbreaks

Cholera outbreaks can spread rapidly, especially after natural disasters, in refugee camps, or in regions with failing infrastructure. Key strategies include:

• Rapid identification and reporting of cases
• Emergency water purification and distribution
• Mass ORS distribution
• Vaccination campaigns
• Establishment of cholera treatment centers

Who is most at risk?

• People without access to clean water or sanitation
• Residents of overcrowded or displaced communities
• Children under five (more vulnerable to dehydration)
• People with weakened immunity
• Travelers to high-risk regions

Frequently asked questions (FAQs)

Practical next steps

1. If you suspect cholera, seek immediate medical care for evaluation and rehydration.
2. Ensure access to safe drinking water and safe food handling practices.
3. During outbreaks, follow public health guidance and consider vaccination if offered.
4. Educate family and community members about hygiene and prevention strategies.

Final notes

Cholera is a preventable and treatable disease. With clean water, sanitation, hygiene education, and rapid access to medical care, the risk of severe illness or death can be dramatically reduced. Public awareness and community-level interventions remain the strongest tools in controlling cholera globally.