Cholera is a bacterial disease usually spread through contaminated water. Cholera causes severe diarrhea and dehydration. Left untreated, cholera can be fatal in a matter of hours even in previously healthy people.
Modern sewage and water treatment have virtually eliminated cholera in industrialized countries. The last major outbreak in the United States occurred in 1911. But cholera is still present in Asia, the Middle East, Latin America, India and sub-Saharan Africa. The risk of cholera epidemic is highest when poverty, war or natural disasters force people to live in crowded conditions without adequate sanitation.
Cholera is easily treated. Death results from severe dehydration that can be prevented with a simple and inexpensive rehydration solution.
Most people exposed to the cholera bacterium (Vibrio cholerae) don't become ill and never know they've been infected. Yet because they shed cholera bacteria in their stool for seven to 14 days, they can still infect others through contaminated water. Most symptomatic cases of cholera cause mild or moderate diarrhea that's often hard to distinguish from diarrhea caused by other problems.
Only about one in 10 infected people develops the typical signs and symptoms of cholera, usually within a few days of infection.
Symptoms of cholera infection may include:
Dehydration may lead to a rapid loss of minerals in your blood (electrolytes) that maintain the balance of fluids in your body. This is called an electrolyte imbalance.
Signs and symptoms of cholera in children
When to see a doctor
If you have diarrhea, especially severe diarrhea, and think you may have been exposed to cholera, seek treatment right away. Severe dehydration is a medical emergency that requires immediate care regardless of the cause.
A bacterium called Vibrio cholerae causes cholera infection. However, the deadly effects of the disease are the result of a potent toxin, called CTX, that the bacteria produce in the small intestine. CTX binds to the intestinal walls, where it interferes with the normal flow of sodium and chloride. This causes the body to secrete enormous amounts of water, leading to diarrhea and a rapid loss of fluids and salts (electrolytes).
Contaminated water supplies are the main source of cholera infection, although raw shellfish, uncooked fruits and vegetables, and other foods also can harbor V. cholerae.
Cholera bacteria have two distinct life cycles — one in the environment and one in humans.
Cholera bacteria in the environment
Cholera bacteria in people
Because more than a million cholera bacteria — approximately the amount you'd find in a glass of contaminated water — are needed to cause illness, cholera usually isn't transmitted through casual person-to-person contact.
The most common sources of cholera infection are standing water and certain types of food, including seafood, raw fruits and vegetables, and grains.
Everyone is susceptible to cholera, with the exception of infants who derive immunity from nursing mothers who have previously had cholera. Still, certain factors can make you more vulnerable to the disease or more likely to experience severe signs and symptoms. Risk factors for cholera include:
Cholera can quickly become fatal. In the most severe cases, the rapid loss of large amounts of fluids and electrolytes can lead to death within two to three hours. In less extreme situations, people who don't receive treatment may die of dehydration and shock 18 hours to several days after cholera symptoms first appear.
Although shock and severe dehydration are the most devastating complications of cholera, other problems can occur, such as:
Preparing for your appointment
Seek immediate medical care if you develop severe diarrhea or vomiting and are in or have very recently returned from a country where cholera occurs.
If you believe you may have been exposed to cholera, but your symptoms are not severe, call your family doctor or general practitioner. Be sure to tell him or her that you suspect your illness may be cholera.
Here's some information to help you get ready, and what to expect from your doctor.
Information to gather in advance
The list below suggests questions to raise with your doctor about cholera.
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment at any time that you don't understand something.
What to expect from your doctor
What you can do in the meantime
If no oral rehydration solutions are available, you can make your own by combining 1 quart (about 1 liter) of bottled or boiled water with 8 level teaspoons (about 40 milliliters) of table sugar and 1 level teaspoon (about 5 milliliters) of table salt.
Tests and diagnosis
Although signs and symptoms of severe cholera may be unmistakable in endemic areas, the only way to confirm a diagnosis is to identify the bacteria in a stool sample.
Rapid cholera dipstick tests are now available, enabling health care providers in remote areas to confirm diagnosis of cholera earlier. Quicker confirmation helps to decrease death rates at the start of cholera outbreaks and leads to earlier public health interventions for outbreak control.
Treatments and drugs
Cholera requires immediate treatment because the disease can cause death within hours.
Cholera cases reported in the United States since 1995 have been traced to sources outside the U.S. or to contaminated and improperly cooked seafood from the Gulf Coast waters.
If you're traveling to cholera-endemic areas, your risk of contracting the disease is extremely low if you follow these precautions:
Last Updated: 2011-03-30
© 1998-2015 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "Mayo Clinic Health Information," "Reliable information for a healthier life" and the triple-shield Mayo logo are trademarks of Mayo Foundation for Medical Education and Research.
Terms and conditions of use