Cholera

What Is Cholera?

Cholera is an acute, diarrheal illness caused by an infection with the bacterium Vibrio cholerae, in the intestines. The infection is often mild or without symptoms, but sometimes it can be severe. Although the illness can be life-threatening, it is easily prevented and treated.

 

In the United States, because of advanced water and sanitation systems, this particular illness is not a major threat. However, everyone, especially travelers, should be aware of how it is transmitted and what can be done to prevent it.

 

Vibrio Cholerae

Vibrio cholerae is the type of bacteria that causes cholera. There are two general types of Vibrio cholerae:

 

Vibrio cholerae Serogroup O1 is the type of Vibrio cholerae that most often causes the disease. Vibrio cholerae Serogroup O139, a Vibrio cholerae Serogroup non-O1 bacterium, is the other cause of the disease.

 

 

How Is It Transmitted?

The disease is usually spread by eating food or drinking water that is contaminated with Vibrio cholerae.

 

There are two ways that Vibrio cholerae usually gets in water or food:

 

It is not likely to spread directly from one person to another; therefore, casual contact with an infected person is not a risk for becoming ill.

 

 

Incubation Period

When a person becomes infected with the bacteria that cause cholera, the bacteria begin to multiply within the intestines. After 24 to 48 hours, symptoms can occur. The period between becoming infected and the start of cholera symptoms is called the incubation period.

 

Symptoms of Cholera

An infection with Vibrio cholerae is often mild or without symptoms, but sometimes symptoms are severe. Approximately 1 in 20 infected people has severe symptoms. These people may experience a rapid loss of body fluids, leading to dehydration and shock. Without treatment, death can occur within hours.

 

 

Making a Diagnosis

In order to make a diagnosis, the doctor will ask a number of questions and perform a physical exam to look for signs of cholera and fluid loss. If the doctor suspects this illness, he or she will ask for a stool sample. This sample will be examined under a microscope for evidence of Vibrio cholerae (see Pictures of Cholera).

 

 

How Is It Treated?

People who develop severe diarrhea and vomiting (in countries where cholera occurs) should seek medical attention promptly. When a diagnosis is made, treatment should begin immediately. If treatment is started early, symptoms and complications can be minimized. Treatments can include:

 

What Is the Prognosis?

If treatment is started in a timely manner, and in adequate volumes, the cholera mortality rate is reduced to well under 1 percent. Without proper treatment, the mortality rate is between 25 and 50 percent.

 

Can It Be Prevented?

In the United States, cholera was prevalent in the 1800s, but has been virtually eliminated by modern sewage and water treatment systems. However, as a result of improved transportation, more people from the United States are traveling to parts of Africa, Asia, and Latin America, where an epidemic is occurring. For these people, prevention involves avoiding contaminated food and water.

 

At this point, a vaccine is not recommended for the prevention of this disease.

 

 

How Common Is Cholera?

Since 1817, there have been seven worldwide cholera pandemics. There is an ongoing global pandemic in Asia, Africa, and Latin America that has lasted for the last four decades. Since 1995, over 80 percent of reported cases have occurred in Africa.

 

This illness has been very rare in industrialized nations for the last 100 years. In the United States, there are zero to five cases per year. Most outbreaks in the United States have occurred in Louisiana and the Gulf of Mexico, from contaminated shellfish.

 

In 2003, 111,575 cholera cases from 45 countries were reported to the World Health Organization.

 

Cholera affects more children than adults, and usually occurs during summer and fall months.