What is Cholera? Understanding the Bacterial Infection That Affects Your Gut

Written by: Sarah Glinski, RD

Updated: November 18th, 2025

While most people think of cholera as a distant, outdated disease, it’s actually a lot more common than you might realize. In fact, it’s estimated that there are between 3 to 5 million cases resulting in up to 120,000 deaths from cholera each year worldwide. Additionally, the number of cholera cases reported to the World Health Organization (WHO) each year continues to be high, emphasizing the importance of awareness, prevention, and modern treatments.

But what is cholera, exactly? This article will explore what causes cholera, how it’s transmitted, how to recognize cholera symptoms, plus how to prevent and treat this serious bacterial illness.

What is Cholera?

Cholera is an acute diarrheal illness caused by the Vibrio cholerae bacteria. While there are many different strains of V. cholerae,only two — O1 and O139 — cause large cholera outbreaks.

Cholera causes diarrhea because of its effects on the small intestine. Once the bacteria reach the small intestine, they adhere to the intestinal lining and produce cholera toxin. This toxin alters electrolyte channels (the tiny “gates” in the lining of the small intestine that control the movement of fluid and minerals in and out of your cells). This leads to profuse watery diarrhea. If left untreated, this rapid loss of fluids can cause severe dehydration, hypovolemic shock, and death.

After the V. cholerae bacterium enters the outside environment (typically through feces), it is extremely infectious for 24 hours. This is why contaminated food and water can lead to numerous cases of cholera in a short period of time.

How is Cholera Transmitted?

Cholera is transmitted through the fecal-oral route. This means that people become infected with the V. cholerae bacteria after eating or drinking food or water contaminated with the feces of an infected person. This most often occurs in areas where sanitation practices and infrastructure are inadequate, and drinking water is unsafe. The risk of contracting cholera is highest during humanitarian crises, natural disasters, and when travelling to regions where cholera is common, including parts of Africa and South-East Asia.

Importantly, even asymptomatic carriers (people who are infected with the bacteria but do not have any symptoms) can still spread the bacteria, making prevention and good hygiene practices essential for limiting the spread of this bacterial infection.

Recognizing Cholera Symptoms

The main cholera symptoms include sudden, large amounts of watery diarrhea and vomiting without a fever, leading to dehydration. People may also experience muscle cramps. While most people only experience mild symptoms, in severe cases, people can lose so much fluid and salt so quickly that their blood pressure drops to dangerously low levels, causing the body to go into shock. Without treatment, this can be deadly, sometimes within hours. Death rates from untreated cholera can be as high as 70%, highlighting the importance of rapid treatment.

Cholera diarrhea often starts with normal stool but quickly becomes a pale, watery liquid with mucus in it, sometimes described as “rice water stools.” The rapid fluid loss and high salt content of the stool are what differentiate cholera from most other diarrheal illnesses.

Cholera Vaccine: A Key Prevention Tool

The first oral cholera vaccine was recognized by the WHO in 2011. There are currently two cholera vaccines available in Canada.

There are several common misconceptions about cholera vaccines. Some of the most common are:

False: “The vaccine gives you complete, lifelong immunity.” In reality, protection isn’t 100%, and typically lasts between 3 months and 3 years, depending on the type of vaccine.
False: “If I’m vaccinated, I don’t need to worry about clean water or hygiene.” While the vaccine reduces your risk of contracting cholera, it doesn’t replace the need for safe drinking water, proper sanitation, and good hygiene practices.
False: “The vaccine can give you cholera.” Some cholera vaccines use a weakened form of cholera that doesn’t cause disease, as it cannot produce the cholera toxin that causes symptoms. Exposing your body to the weakened form of cholera stimulates the immune system, thereby preventing an infection.
False: “It works immediately after you get it.” It may take as long as two weeks for protection to be established, depending on which cholera vaccine you take.
False: “Only people in outbreak areas need the cholera vaccine.” It’s also recommended for travellers to high-risk regions and for people in areas with poor access to clean water. Humanitarian aid workers, including healthcare professionals, should also consider the vaccine, particularly if they’re going to be travelling to endemic areas.

Protecting Yourself Against Cholera

Cholera outbreaks are linked to limited access to safe drinking water, sanitation, and poor hygiene practices. This can occur for a variety of reasons, such as conflict, unplanned urbanization, climate change, or a lack of safe water, basic sanitation, and hygiene services.

You can reduce your risk of cholera infection by:

Practicing safe food and water habits while travelling, such as drinking bottled or treated water, avoiding raw or undercooked seafood, and eating food that’s been cooked and is served hot
Regularly washing your hands with soap
Using clean toilets
Ensuring access to clean drinking water
Getting a cholera vaccine before travelling to high-risk areas

If you’re heading to a higher-risk area, being prepared is essential. Pack water treatment supplies, soap, and hand sanitizer.

Cholera Treatment: What You Need to Know

The primary cholera treatment is oral rehydration therapy. The amount of fluid given depends on how much fluid was lost. Given that fluid loss can occur so quickly, rehydration therapy should begin immediately to prevent the complications associated with excessive fluid and mineral loss.

If the infection is identified quickly, oral rehydration therapy is typically sufficient for treating the illness. However, people with severe dehydration or those experiencing severe vomiting will typically need intravenous fluids. Oral rehydration salts can be given as soon as the person infected is able to drink and keep down liquids.

In addition, antibiotics may also be used to reduce the duration of the infection when combined with rehydration therapy. However, while antibiotics can be used to treat cholera, mass administration of these medications to prevent cholera outbreaks is not recommended by the WHO, as it hasn’t been shown to limit the spread of cholera and may lead to antibiotic-resistant V. cholerae.

Additionally, in children aged 6 months to 5 years, supplementing with zinc alongside rehydration therapy can shorten the duration of illness and volume of diarrhea.

In lower-resourced, rural communities and other remote locations, people may have to travel long distances to receive care. Plus, during humanitarian crises or natural disasters, clinics can quickly become overwhelmed and important supplies can become scarce. That’s why it’s important to consider vaccination when travelling to areas where there is a risk you might be exposed to cholera.

Final Thoughts

While cholera is a serious bacterial infection that is common in many regions of the world, it’s also a very preventable illness.

Education about sanitation and hygiene practices, distribution of cholera vaccines, and early treatment with oral rehydration salts or intravenous fluids all play a role in preventing and treating the disease.

If you’re travelling soon, talk with your healthcare provider about travel precautions and vaccines recommended for the region you’re travelling to. Remember, preventing the spread of cholera is key, so being prepared and getting vaccinated before travel to endemic areas is an important part of your travel planning.

References

Government of Canada (2017, April 1). Cholera and enterotoxigenic Escherichia coli (ETEC) travellers’ diarrhea vaccine: Canadian Immunization Guide. Retrieved August 26, 2025, from https://www.canada.ca/en/public-health/services/publications/healthy-living/canadian-immunization-guide-part-4-active-vaccines/page-3-cholera-enterotoxigenic-escherichia-coli-travellers-diarrhea-vaccine.html#a2
Ojeda Rodriguez JA, Hashmi MF, Kahwaji CI. Vibrio cholerae Infection. [Updated 2024 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526099/
World Health Organization (2024, December 18). Multi-country outbreak of cholera, External situation report #21 – 18 December 2024. Retrieved August 26, 2025, from https://www.who.int/publications/m/item/multi-country-outbreak-of-cholera–external-situation-report–21—18-december-2024
Harris, J. B., LaRocque, R. C., Qadri, F., Ryan, E. T., & Calderwood, S. B. (2012). Cholera. Lancet, 379(9835), 2466. https://doi.org/10.1016/S0140-6736(12)60436-X
World Health Organization (2024, December 5). Cholera. Retrieved August 8, 2025, from https://www.who.int/news-room/fact-sheets/detail/cholera
World Health Organization (2017). Cholera vaccines: WHO position paper – August 2017. Weekly Epidemiological Record, 92(34), 477-500. https://iris.who.int/bitstream/handle/10665/258763/WER9234.pdf?sequence=1
CDC (2025, May 29). Cholera Vaccines. Retrieved August 12, 2025, from https://www.cdc.gov/cholera/prevention/cholera-vaccines.html
Sit, B., Fakoya, B., & Waldor, M. K. (2022). Emerging Concepts in Cholera Vaccine Design. Annual Review of Microbiology, 76, 681–702. https://doi.org/10.1146/annurev-micro-041320-033201
CDC (2025, July 23). How to Prevent Cholera. CDC. Retrieved August 26, 2025, from https://www.cdc.gov/cholera/prevention/index.html