What are the other Names for this Condition? (Also known as/Synonyms)
- Infection by Vibrio Cholerae
What is Cholera? (Definition/Background Information)
- Cholera is an acute illness of the small intestine caused by the bacteria Vibrio cholera. It is characterized by sudden, intense watery diarrhea and vomiting, leading to dehydration.
- Vibrio cholerae is usually spread through contaminated water sources. The bacterium produces a toxin (poisonous substance made by organisms) that increases the release of chloride (and thus water) from the cells of the intestine, leading to a high volume of watery diarrhea.
- Even though Cholera can be deadly if left untreated, it has an excellent prognosis with prompt recognition and aggressive fluid replacement therapy.
Who gets Cholera? (Age and Sex Distribution)
- Any individual irrespective of age, gender, race, or region drinking unsafe water (or food contaminated with Vibrio cholerae) are prone to be affected by Cholera
- It is more common in developing countries and in countries where access to safe water and proper sanitation are not available. Cholera is endemic in more than 50 countries
- Epidemics (rapid spreading of Cholera affecting many in a short period of time) have been observed in countries where Cholera is uncommon (or immune naive). Cholera epidemics can also occur in regions where it is endemic
What are the Risk Factors for Cholera? (Predisposing Factors)
The risk factors of Cholera include:
- Poor sanitary conditions: Individuals living in areas where sanitary conditions are not adequate and where there is a lack of regular supply of safe drinking water are at high risk for contracting Cholera. These places can be refugee camps, densely populated areas, and even some underdeveloped countries
- Whenever natural disasters, such as earthquakes or floods occur, they disrupt sanitary conditions and clean water supply, putting individuals at risk
- Reduced stomach acid: Acid in the stomach normally kills Cholera-causing bacteria to a great extent. Individuals with decreased acid (hypochlorhydria) or absent acid (achlorhydria) production are at an increased risk compared to individuals with normal acid production
- Children, especially in endemic regions, are more vulnerable in comparison to older adults. However, in regions where Cholera is uncommon, all age groups are equally affected
- Contaminated water source: The bacteria are found in the feces in individuals affected with Cholera. In areas where there is poor sanitation, these individuals can contaminate the water source, such as public wells, thus placing other individuals and the community at risk
- Type O blood: Individuals who have type “O” blood group are at risk to get a severe form of Cholera
- Individuals with retinol (vitamin A) deficiency have an increased risk of Cholera, especially the severe form of the disease
- Researchers believe that there could be a genetic basis predisposing an individual to the infectious disease
- Contaminated food source: Individuals consuming raw or undercooked shellfish, oysters, unpeeled fruits, or uncooked vegetables are at an increased risk
- Grains (like rice or millet) can become contaminated with Cholera when cooked with unsafe water and allowed to remain at room temperatures for long hours
It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.
Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.
What are the Causes of Cholera? (Etiology)
The causes of Cholera include:
- Cholera is caused by the bacteria Vibrio cholera. Even though there are many types (serotypes) of Vibrio cholera, types O1 and O139 are known to cause Cholera epidemics
- Vibrio cholerae produce a toxin called CTX, which gets attached to the walls of the intestine. The toxin causes excess outflow of chloride ions and water into the small intestine, resulting in “rice water” diarrhea. There is also a loss of electrolytes with the diarrhea
There are two major sources of the bacteria.
- Environment, where the bacteria may be present, especially in warm, stagnant water bodies
- Individuals infected with the bacteria may contaminate water and food sources. Such affected individuals may or may not have the disease, but are more likely to spread and cause the disease than the environment itself
What are the Signs and Symptoms of Cholera?
The signs and symptoms of Cholera include:
- After an individual gets infected, the symptoms may begin within 12 hours to 5 days
- Painless diarrhea: Sudden “rice water” type watery diarrhea is the main symptom of Cholera
- Nausea and vomiting, especially during the early course of the illness
- Some individual may have abdominal discomfort or cramping
Dehydration: The loss of fluids from the body can lead to dehydration, which can be manifested as:
- Excessive thirst
- Sunken eyes
- Dry mouth
- Dry, cold skin
- Low urine output
- Low blood pressure
- Rapid, feeble pulse, irregular heartbeat
- The loss of electrolytes that may cause:
- Muscle cramps and weakness
- Shock (inadequate volume and/or pressure inside the blood vessels)
In addition, the following signs and symptoms of Cholera may be especially seen in small children:
How is Cholera Diagnosed?
The following procedures may be used to diagnose Cholera:
- Evaluation of the individual’s medical history and a thorough physical examination
- During history taking, the physician may enquire the following:
- When the symptoms began and whether they are becoming worse
- About recent food intake, dietary habits, water source, sanitation methods, etc.
- The physician shall at the outset thoroughly check for signs and symptoms of Cholera. The diagnosis is initially suspected in any individual who has sudden watery diarrhea and suffers from dehydration
Other diagnostic tests depend on their availability:
- Dark field microscopy may demonstrate active comma-shaped Vibrio cholerae bacteria when the stool is examined. This is a rapid test
- Rapid cholera dipstick test: This test allows healthcare providers in rural areas to easily confirm the presence of Cholera bacteria in the stool and provide the required treatment immediately
Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.
What are the possible Complications of Cholera?
The complications of Cholera include:
- Hypoglycemia or low blood sugar: When affected individuals are unable to eat properly, their sugar level in the blood may drop which may further lead to seizures (fits), unconsciousness, and death. This is especially seen in children
- Electrolyte disturbances: Diarrhea causes low levels of potassium (hypokalemia), sodium (hyponatremia), and calcium (hypocalcemia) in the blood. Hypokalemia may affect the proper functioning of heart and nerves and can become life-threatening
- Kidney failure (dysfunction) may further complicate the already ‘fluid volume’ depleted individual
- The elderly are at increased risk to get stroke, renal failure, or aspiration pneumonia (the entry of stomach contents into the lungs) due to vomiting
Death (Cholera gravis): Cholera can become fatal within hours because of the excess loss of fluids and electrolytes from the body.
How is Cholera Treated?
Cholera needs immediate medical attention since it can become fatal within a few hours. It is very important to monitor the fluid loss and match it with adequate replacement.
The management and treatment of Cholera involves:
- Rehydration: Oral rehydration solution (ORS) is given to replace lost fluid and electrolytes. The World Health Organization also suggests the use of homemade ORS in emergent situations
- Intravenous fluids: When people suffer from severe dehydration, they need to be given fluids through the veins to replace the lost fluids. Signs of severe illness include loss of thirstiness, unconsciousness, or shock. Once the individual becomes better and is able to take in fluids orally, switching to oral fluids is more advantageous than continuing with intravenous fluids
- Antibiotics are mainly given to reduce the volume of diarrhea, shorten the duration of illness, and to prevent the spread of Cholera. Such antibiotics include Doxycycline and Azithromycin
- Zinc supplements help in reducing the duration of diarrhea in children
How can Cholera be Prevented?
The preventative measures of Cholera include:
- The most important method to prevent Cholera is educating individuals who live in Cholera prevalent areas on hygiene, proper sanitation, and access to safe water
- Washing hands with water and soap after bathroom/toilet use will help prevent the spread of the bacteria
- When water source is questionable, commercially available bottled water or treated water (ozonized, filtered, chlorine disinfected, reverse osmosis, UV treated, etc.) should be used for drinking
- Proper washing of fruits and vegetables before consuming them
- Avoiding raw or uncooked fish and seafood
- Avoiding unpasteurized (untreated) milk
- Thorough cooking of food and avoidance of food that has been left in room temperature for longer periods, especially in regions where Cholera is prevalent
Oral cholera vaccines are available in some countries. If you are planning to travel abroad, it is advisable to please ask your healthcare provider about the availability of the vaccine.
What is the Prognosis of Cholera? (Outcomes/Resolutions)
- With prompt and adequate fluid replacement, complete and full recovery is possible, and the prognosis of Cholera is good
- Severe dehydration can cause death if it is not adequately treated
Additional and Relevant Useful Information for Cholera:
- The World Health Organization (WHO) estimates that there are over 3 million cases of Cholera every year, especially in India, parts of Asia and Africa
- Cholera has been described in Sanskrit literature, almost as early as the 5th century B.C.