Cholera - Causes, Symptoms, Diagnosis and Treatment

What is cholera?

Cholera is an acute, infectious disease caused by the consumption of water or food contaminated with the bacterium Vibrio cholerae.

Cholera is a public health concern in developing countries all over the world, especially in Africa, south Asia, and Latin America. Cases among travelers to and from developed countries are rare; however, some outbreaks in the United States have been caused by contaminated seafood brought into the country by travelers.

What causes cholera?

Vibrio cholerae is usually found in impure water supplies because of the unsanitary disposal of excrement. Person-to-person transmission is rare. It is usually transmitted by consuming contaminated food or water from:

  • Municipal water supplies

  • Ice made from municipal water

  • Foods and beverages bought from street vendors

  • Vegetables irrigated with fresh sewage

  • Raw or inadequately cooked fish and seafood taken from sewage-polluted waters

How does the Vibrio cholerae bacterium affect the body?

The bacterium that causes cholera is usually very sensitive to the acids present in the stomach and digestive tract. Small amounts of bacteria are killed by the stomach acids before they can establish themselves in the body. But, when large numbers of the bacteria overwhelm the body's natural defenses, they grow in the small intestine and are passed in the fecal material of the infected person. Infected persons who have mild cases or show no symptoms of the disease--especially those who have poor personal hygiene habits--spread the infection by direct contamination of food with infected excrement.

Can cholera be prevented?

The best preventives for cholera are:

  • Only use water that has been boiled or chemically disinfected for:

    • Drinking, or preparing beverages such as tea or coffee

    • Brushing teeth

    • Washing face and hands

    • Washing fruits and vegetables

    • Washing eating utensils and food preparation equipment

    • Washing the surfaces of tins, cans, and bottles that contain food or beverages

  • Do not eat food or drink beverages from unknown sources

    • Any raw food could be contaminated, including:

      • Fruits, vegetables, salad greens

      • Unpasteurized milk and milk products

      • Raw meat

      • Shellfish

      • Any fish caught in tropical reefs rather than the open ocean

A cholera vaccine is available for individuals aged two years and older, and has been proven safe and effective. According to the World Health Organization, six months after the vaccine is administered, the efficacy rate is 85 to 90 percent in all age groups, and declines to 62 percent in adults in one year. Currently, no country requires the cholera vaccine for entry if arriving from cholera-infected countries.

Treatment for cholera

For diarrhea that is worse than normal, it is best for the traveler to consult a doctor rather than try self-medication. Seek medical help if diarrhea becomes severe and watery, or if vomiting occurs.

Specific treatment for cholera will be determined by your doctor based on:

  • Your overall health and medical history

  • Extent of the disease

  • Your tolerance for specific medications, procedures, or therapies

  • Expectations for the course of the disease

  • Your opinion or preference

Treatment for cholera may involve rehydration with:

  • Oral rehydration solutions

  • Intravenous solutions in the most severe cases

Treatment with antibiotics is sometimes used to decrease the duration of illness, but are not thought to be necessary for successful treatment.