A contagious diarrhoeal disease

Cholera is a severe, highly contagious diarrhoeal disease, caused by vibrio Cholerae, from the gram negative bacillus.

Cholera disease and symptoms

The disease results in a profuse diarrhoea, sometimes with the occurrence of vomiting a few hours after the ingestion of contaminated (by V. cholerae bacillus) food or water. For most of the victims, the symptoms subside after a few days, but sometimes the diarrhoea and the vomiting are so intense that dehydration leads to death, if no rehydration measure is provided to the patient.

Symptoms of cholera infection may include:

  • Diarrhea. Cholera-related diarrhea comes on suddenly and may quickly cause dangerous fluid loss — as much as a quart (about 1 liter) an hour. Diarrhea due to cholera often has a pale, milky appearance that resembles water in which rice has been rinsed (rice-water stool).
  • Nausea and vomiting. Occurring especially in the early stages of cholera, vomiting may persist for hours at a time.
  • Dehydration. Dehydration can develop within hours after the onset of cholera symptoms. Depending on how many body fluids have been lost, dehydration can range from mild to severe. A loss of 10 percent or more of total body weight indicates severe dehydration.

Signs and symptoms of cholera dehydration include irritability, lethargy, sunken eyes, a dry mouth, extreme thirst, dry and shriveled skin that's slow to bounce back when pinched into a fold, little or no urine output, low blood pressure, and an irregular heartbeat (arrhythmia).

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. 

More information here.

Vibrio Cholerae

Vibrio cholerae bacillus is found in natural surroundings, such as brackish water of estuaries where the surface of the water is colonised with seaweed and copepods, which nurture the bacillus, enabling it to persist without human contact for long periods of time.

The first link between cholera disease and contaminated drinking water was found in England in 1854, by Dr. John Snow, a famous physician and medical scientist. He proposed a precise model for the study of the cause of the disease (State of the art review, J. Snow, 1855).
Once convinced of the plausibility of the model, developed countries in Europe and North America made massive investments in infrastructures for potable water treatment and supply and sewage treatment. These investments in Water, Sanitation and Hygiene, eliminated the threat of cholera in the major developed cities in Europe and North America.