Overview

Cholera is a bacterial disease that is commonly spread by contaminated water. Cholera causes extreme dehydration and diarrhoea. Left untreated, cholera can be lethal within hours, even in people who were previously healthy.

Modern treatment of sewage and water almost eliminated cholera in developed countries. But cholera still exists in Africa, Southeast Asia and Haiti. When poverty, war or natural disasters cause people to live in crowded conditions without sufficient sanitation, the risk of a cholera outbreak is highest.

Cholera is easily treated. Death from severe dehydration can be prevented with a simple and inexpensive rehydration solution.

Symptoms

Most people exposed to the cholera bacterium don’t become ill and don’t know they’ve been infected. But since they’ve lost seven to 14 days of cholera bacteria in their urine, they can still infect others by polluted water.

Many cases of cholera causing symptoms cause mild to moderate diarrhoea which is often difficult to tell apart from diarrhoea caused by other issues. Others show more severe Cholera signs and symptoms, commonly within a few days of infection.

Symptoms of cholera infection can include:

Diarrhea: Cholera-related diarrhea comes on suddenly and can quickly cause dangerous fluid loss — as much as a quart an hour. Cholera-related diarrhea also has a yellow, milky appearance which is similar to water in which rice has been rinsed.

Nausea and Vomiting: Vomiting happens in the early stages of cholera in particular, which can last for hours.

Dehydration: Dehydration may develop within hours after cholera symptoms start and range from mild to extreme. A loss of 10% or more of body weight indicates severe dehydration.

Cholera dehydration signs and symptoms include irritability, weakness, sunken eyes, dry mouth, intense thirst, dry and shrivelled skin that is sluggish to bounce back when pinched in a fold, little or no urinating, low blood pressure, and an irregular heartbeat.

When to see a doctor

For developed nations the possibility of cholera is small. Also in areas where it occurs, if you meet food safety guidelines you are not likely to become contaminated. Even, cholera cases occur all over the world. If after visiting an area with active cholera you experience serious diarrhea see your doctor.

If you have diarrhea, particularly severe diarrhea, and think you may have been exposed to cholera, seek immediate treatment. Extreme dehydration is a medical emergency, requiring urgent treatment.

Causes

A bacterium called Vibrio cholerae causes cholera infection. The toxin causes large quantities of water to be secreted by the body, leading to vomiting and a rapid loss of fluids and salts.

In all people who are exposed to them, cholera bacteria do not cause disease, but they also move through the bacteria in their stool which can contaminate food and water sources.

Contaminated water sources are the principal cause of infection with cholera. The bacterium lies in:

Raw fruits and vegetables: Raw, unpeeled fruits and vegetables are a common source of infection with cholera in areas where cholera is contained. Uncomposted manure fertilizers or irrigation water containing raw sewage in developing countries can contaminate on-field produce.

Grains: In regions where cholera is widespread, cholera bacteria may grow in grains such as rice and millet that are contaminated after cooking and kept for several hours at room temperature.

Risk factors

Everyone is susceptible to cholera, with the exception of infants who get immunity from nursing mothers who have previously had cholera. Still, certain factors can make you more vulnerable to the disease or more likely to have severe signs and symptoms.

Risk factors for cholera include:

Household exposure: If you live with someone who has the disease you are at an increased risk of cholera.

Type O Blood: For reasons which are not entirely clear, people with blood type O are twice as likely to develop cholera compared to people with other types of blood.

Raw or undercooked shellfish: While industrialized nations are no longer experiencing large-scale cholera outbreaks, eating shellfish from waters known to harbor the bacteria increases the risk considerably.

Complications

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 hours. In less severe cases, people who don’t get care can die from hours of dehydration and shock to days after symptoms of cholera first appear.

Although the worst complications of cholera are shock and extreme dehydration, other problems can occur like:

Low blood sugar: Dangerously low levels of blood sugar — the body’s main energy source — can occur when people become too ill to eat. Children are at the highest risk of this condition which can lead to seizures, unconsciousness and even death.

Low potassium levels: People with cholera lose significant quantities of minerals in their stools like potassium. Very small levels of potassium interfere with the activity of the heart and nerve and are life-threatening.

Kidney failure: When the kidneys lose their filtering capacity, large amounts of fluids, other electrolytes and waste build up in the body — a life-threatening disease. Kidney failure also causes shock in persons with cholera.

Prevention

Cholera is rare in the United States with a few cases related to travel outside the U.S.

If you fly to places known to have cholera, if you take these precautions the chance of contracting the disease is extremely low:

• Wash your hands with soap and water frequently, especially after using the toilet and before handling food. Rub soapy, damp hands together for 15 seconds minimum before rinsing. Where soap and water are not available, use a hand sanitizer based on alcohol.
• Drink only safe water, like bottled water or boiled or disinfected water. And brush your teeth using bottled water.
• Hot beverages, including canned or bottled beverages, are usually free, but clean the outside before you open them up.
• Eat food which is completely cooked and hot and avoid food from street vendors, if possible. If you do buy a meal from a street vendor, make sure it’s cooked in your presence and served hot.
• Avoid sushi, and any sort of raw or poorly cooked fish and seafood.
• Stick to fruits and vegetables that you can peel yourself, like bananas, oranges and avocados. Stay away from salads and fruits that can’t be peeled, such as grapes and berries.

Cholera vaccine

In the United States, a vaccine called Vaxchora is available for adults traveling from the United States to areas plagued by cholera. It is a dose of liquid taken by mouth at least 10 days before traveling.

Some other countries offer oral vaccines also. Contact your doctor or local office of public health for more information about these vaccines. Even with the vaccine, to prevent cholera, it is necessary to take the precautions set out above