Cholera, a Disease That Keeps Repeating Its History

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Medical Author: Charles Davis, MD, PhD
Medical Editor: Melissa Conrad Stöppler, MD

Again, a cholera epidemic strikes a human population. This time the cholera epidemic is in Haiti, a small country that has undergone large disasters. On Jan. 12, 2010, a huge earthquake killed over 300,000 people, leaving Haiti with a huge homeless population and its main city, Port-au-Prince, devoid of most normal services and sanitary conditions. Many city residents left, but the more rural areas were not any better at supplying people with sanitary conditions. Many Haitians simply turned to their largest river in the country for water to drink, bathe, wash clothes, and swim in. This is a perfect environment for the development and spread of cholera and other diseases. As of Oct. 26, 2010, at least 250 people have died from cholera in Haiti.

Researchers speculate that someone imported cholera to Haiti since the disease has not been seen there in over 50 years; bacterial genetic studies are being done at Harvard Medical School to help determine the source. Whatever the source, it is clear that Vibrio cholerae bacteria have arrived and spread widely as the organisms can now even be isolated from river water.

Because the bacteria cause an initial painless watery diarrhea (it appears to resemble "rice water" and smells fishy) and are present in diarrhea fluid often in large numbers, Vibrio strains help spread themselves into the environment. Many "fortunate" patients may have mild diarrhea (about 70%-80%) and not know they have cholera. Others have such aggressive diarrhea (250 ml/Kg fluid loss over 24 hours) that they develop nausea, vomiting, and stomach cramps. These patients quickly become dehydrated and so weak that the ill individuals soil themselves and their immediate surroundings and cannot clean up after themselves. Such patients, unless quickly treated with oral and IV fluids and frequently antibiotics, may die from dehydration (hypovolemic shock) and electrolyte abnormalities. Pregnant females, infants, and small children are more susceptible to severe illness than the general population. Children often appear sleepy and can lapse into a coma. In susceptible individuals, death can ensue in a matter of hours after symptoms appear. In some populations that have not experienced cholera in many years, untreated patients can have a 50% death rate.

The history of cholera outbreaks keeps repeating; in the last 10 years, there have been significant outbreaks in India, Iran, Vietnam, and several African countries. For example, currently in Nigeria, as of Oct. 26, at least 1,555 deaths have occurred in its ongoing outbreak and the outbreak has spread to the neighboring country of Cameroon, where cholera deaths have started to claim lives. The repeating cholera is likely due to the repeated human problems; the Nigerian health minister estimates that two-thirds of Nigerians have no access to safe drinking water and 60% of the population have access no toilet facilities of any kind. It seems fairly simple to state that if governments and world organizations want to break this pattern of repeating cholera outbreaks, the best place to start is to make safe and sanitary water supplies, and provide toilet facilities and food to impoverished people or to people in disaster areas where such items have been compromised. Doing it is another story.

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Bowel regularity means a bowel movement every day. See Answer