Cholera: causes, symptoms, infection, therapy and prognosis

Cholera is an endemic and potentially dangerous disease characterized by the frequent excretion of watery diarrhea and often accompanied by vomiting.
The consequences are hypovolemic shock and acidosis.
Vibrio cholerae is a gram-negative bacterium in the form of a “comma” with a single scourge for locomotion.

There are many strains of Vibrio cholerae, some of them pathogenic, while others can cause mild or asymptomatic infection.
Other strains of Vibrio cholerae can occasionally cause isolated outbreaks of milder diarrhea, while the vast majority do not cause disease.
The transmission to humans takes place via water and food.

If a person has ingested contaminated water or food, the bacteria in the intestine release toxins that lead to severe diarrhea.


Types of Vibrio cholerae

There are two general types of Vibrio cholerae:

  1. Vibrio cholerae serogroup O1 is the bacterium responsible for most cholera outbreaks.
  2. Vibrio cholerae serogroup non-O1, there are about 70 species of Vibrio cholerae non-O1, these species rarely cause diarrhea.

How does cholera spread?

Transmission occurs only by drinking water contaminated with the feces of an infected person.
The infection can occur via contaminated water or via food that has been washed with contaminated water.
This type of transmission often occurs in areas without adequate hygiene and sewerage.
Food spread can occur when a human eats raw or short-cooked crustaceans.
For example, people in the United States have gotten cholera by eating short-cooked
crustaceans from the Mexican Gulf.
Human-to-human transmission is unlikely.

Causes of cholera

Sources of cholera can include:

  • Municipal water supply
  • Ice cubes made of water from the tap
  • Food and drinks from street sales
  • Vegetables irrigated with sewage
  • Raw or short-cooked fish or fish caught in dirty waters

Symptoms of cholera

Only one in ten people develops the typical signs and symptoms of cholera.
The incubation period ranges from 1 to 5 days.
Symptoms of cholera infection may include:

Diarrhea. Diarrhea caused by cholera occurs suddenly and quickly and can lead to dangerous fluid loss, sometimes up to a liter per hour.
Diarrhea caused by cholera often looks milky and bright, resembling water in which rice was cooked.
Patients with cholera go to the toilet up to 50 times. If the symptoms are so pronounced, you have to intervene immediately.
In other diseases that cause gastroenteritis, watery diarrhea occurs less often.

Nausea and vomiting. They occur in the initial and final stages of cholera, vomiting can sometimes persist for hours.

Dehydration. After the first cholera symptoms appear, dehydration may occur in the following hours. Depending on the amount of body fluid lost, dehydration can vary from mild to severe. A loss of 10 percent or more of total body weight indicates severe dehydration.

Other signs and symptoms of dehydration caused by cholera include:

  • Irritability
  • Extreme fatigue
  • Sunken eye sockets
  • Xerostomia
  • Extreme thirst
  • Wrinkled and dry skin that stretches slowly after pinching
  • Low amount of urine production
  • Hypotension
  • Irregular heartbeat (arrhythmia)

Dehydration can lead to rapid loss of minerals (electrolytes) in the blood, which maintain the balance of body fluids. This phenomenon is called electrolyte derailment.

An electrolyte derailment can lead to severe signs and symptoms such as:

  • Leg cramps. They are formed by rapid loss of salts such as sodium, chlorine and potassium.
  • Shock. This is one of the serious complications of dehydration. It occurs when the volume of blood decreases, leading to a decrease in blood pressure and a decrease in the amount of oxygen in the body. If left untreated, hypovolemic shock can lead to death in a matter of minutes.

In most cases of symptomatic cholera, there is mild to moderate diarrhoea, which is often difficult to distinguish from diarrhea caused by other problems.

Diagnosis of cholera

To make the diagnosis, proceed as follows:

  • Evaluation of symptoms usually associated with watery diarrhoea associated with nausea, vomiting and abdominal cramps
  • Creation of a stool culture of the patient.
  • In endemic cholera areas, a rapid immunochromatographic test is usually performed. A stick is held in a stool sample and then the colored lines are read.
  • The diagnosis can also be made on the basis of a blood test for antibodies to Vibrio cholerae.
  • Although more than 100 serogroups (based on antigens from cell surfaces) of Vibrio cholerae have been identified, only two are responsible for the cholera epidemic: serogroups O1 and O139.

What is the therapy for cholera?

Since death from cholera is a consequence of dehydration, the therapy consists of oral rehydration. It is necessary to ingest a large amount of water mixed with sugar and salt.

Pre-mixed mixtures are available in the pharmacy, but in severe cholera cases, the fluid must be administered intravenously.

Antibiotics can shorten the duration of illness, but rehydration is still necessary even if antibiotics are taken.

One should not use remedies for diarrhea, because this would prevent the expulsion of bacteria from the body.

Antibiotic resistance is increasing in many parts of the world. Bangladesh, for example, has the highest number of resistant cases to tetracycline, trimethoprim and sulfamethoxazole, as well as erythromycin.

What is the prognosis for cholera?

The consequences of cholera can vary greatly, depending on the severity of dehydration and the speed with which the patient responds to therapy.
The death rate from untreated cholera can be 50-60% during major epidemics, but can be reduced to about 1% if treatment is initiated quickly.
As a rule, the prognosis is better if the symptoms are not severe and the dehydration is not excessive.
If dehydration is kept under control, the prognosis is often excellent.


Five pieces of advice for preventing cholera.

1.Drink and use safe water.

Water filled into sealed bottles and carbonated drinks in cans or bottles can be used without worries.
For brushing your teeth, washing food, preparing food and making ice cubes, you should avoid water from the tap.
You should clean the area for food preparation and dishes with soap and water and also completely dry cutting boards and utensils before use.

To make sure that the water is suitable for drinking:

  • Boil water for at least 1 minute
  • Always store boiled water in a clean and covered container

2.Wash hands with soap and clean water:

  • Before eating or preparing food
  • Before children are fed
  • After use of the toilet
  • After a child’s bottom has been cleaned
  • After caring for a sick person with diarrhea

If no soap is available, you can rub your hands several times with sand or ash and rinse them off with clean water.

3.Use a latrine or bury the droppings; Do not empty the intestines into a puddle of water.

  • For disposal of faeces, use a latrine or other sanitary facilities, such as chemical toilets.
  • After defecation, wash hands with soap and clean water.
  • Clean the toilet and the surfaces contaminated with stool with a bleach solution for home use.

What if you can’t use a toilet to get out?
At least 30 meters from puddles of water, empty the intestines, and then bury the feces in the ground.
Dispose of plastic bags containing feces in the latrine or at a disposal point, if any, or buried in the ground.

4.Cook food well (especially fish), leave covered, eat while it is hot and peel fruits and vegetables completely.
Cook crustaceans (such as crabs, shrimps, mussels) until they are also very hot inside.

* Avoid raw foods, except peeled fruits and vegetables.

5.Clean — in the kitchen and in places where the family does their laundry.
Wash your own body, children, diapers and clothes at least 30 meters away from drinking water sources.

Risk zones for cholera

Worldwide, cholera cases have been steadily increasing since 2005 and the disease still occurs in many areas, including Africa, Southeast Asia, India and Haiti.

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