Cholera is a bacterial infection of the small intestine that can cause acute diarrhea and intense dehydration.
History has seen seven major pandemics (global epidemics) of cholera. The seventh pandemic began in 1961 when cholera reemerged in Indonesia and spread over most of the earth; it still rages today. At the beginning of the 21st century, cholera infected about 3 to 5 million people a year worldwide and about 100,000 of them died.
The epidemic is spreading almost everywhere where the lack of hygiene allows it to infect humans who seem to be the only host of the bacteria. The bacterium that causes cholera is most productive in times of flood and war as these events can reduce the availability of clean water. Cholera continues to plague Asia, Africa, the Middle East, Central America and South America. The last outbreak occurred in Haiti.
Around the world, cholera kills about 4% of people who develop severe symptoms. This proportion includes those who are treated too late or inappropriately and those who do not access medical care.Less than 1% of severely affected people will die of the disease if treated quickly and appropriately.
Causes Of Cholera
Cholera is caused by a bacteria called Vibrio cholerae . People get cholera by drinking water or eating foods that are infected with the bacteria. Once swallowed, it colonizes the lining of the small intestine and releases a toxin (poison) that can cause the body to evacuate fluid inside the small intestine, causing watery diarrhea.
The disease is usually transmitted by water contaminated with human faeces, but it can be transmitted through the ingestion of contaminated food, particularly raw or undercooked seafood or shellfish. Most people infected with cholera have no symptoms, but they carry bacteria for a few weeks and slowly excrete them in the wastewater.
This is not, of course, a major problem in countries with flush toilets and water treatment plants. Canada, the United States, and Western Europe report only rare cases of cholera, and these are often travelers returning from a high-risk country.
Symptoms and Complications
About 25% of people who ingest the bacteria have the special symptoms called cholera. Of these, 80% will experience mild to moderate diarrhea, while 20% will experience intense watery diarrhea that can threaten their lives if not treated appropriately. People who do not have cholera will not have any symptoms at all, although they will often shed the bacteria in their stool, which may transmit it to others.
The reasons why the disease develops in some people while others are not affected by this bacterial toxin are not known. Most adults in cholera-endemic areas have antibodies that help protect them from the disease. In these countries, severe symptoms are much more common among children and people with other underlying diseases such as AIDS.
Vibrio bacteria are killed by stomach acid. Research has shown that people with low levels of acid in their stomachs (eg people who use antacid drugs) are much more likely to contract cholera. O-type people also appear to be at increased risk.
When cholera causes symptoms, the main one is liquid diarrhea: it is so important that it quickly empties the body of its water, its salts and its minerals. The first liquid stool appears 1 to 3 days after infection, and from that moment you can lose up to one liter of fluid per hour.Vomiting may accompany diarrhea.
Other symptoms of advanced cholera include:
- muscle cramps;
- reduced or absent urinationweakness;
- a running pulse;
- the eyes recessed in the orbits;
- a wrinkled skin of the fingers.
Cholera usually lasts 3 to 6 days, but if left untreated, it can lead to shock due to dehydration, kidney failure, coma and death
Diagnosis and treatment of Cholera
- A doctor may suspect cholera if a patient has severe watery diarrhea, vomiting and rapid dehydration, especially if they have recently traveled to a place with a recent history of cholera or poor hygiene, or if they have recently consumed crustaceans.
- A stool sample will be sent to a laboratory for testing, but if cholera is suspected, the patient should begin treatment before the results return.
- This is normally a dehydration that results in the death of cholera, so the most important treatment is to give an Oral Hydration Solution (ORS), also known as Oral Rehydration Therapy (ORT).
- The treatment consists of large volumes of water mixed with a mixture of sugar and salts.
- Pre-packaged blends are commercially available, but widespread distribution in developing countries is limited by cost, so that homemade ORS recipes are often used, with common ingredients.
- Severe cases of cholera require replacement of intravenous fluid. An adult weighing 70 kilograms will have at least 7 liters of intravenous fluids.
- Antibiotics can shorten the duration of the disease, but the WHO does not recommend the massive use of antibiotics for cholera, because of the increasing risk of bacterial resistance.
- Anti-diarrheal medications are not used because they prevent bacteria from being evacuated from the body.
- With proper care and treatment, the mortality rate should be about 1 percent.
Cholera prevention and risk reduction
- Cholera is often spread in food and because of poor hygiene. Some simple measures can reduce the risk of contracting cholera.
- Handwashing is important to prevent the spread of the disease.
- When traveling to areas where the disease is endemic, it is important to:
- Eat only fruits that you have peeled
- Avoid salads, raw fish and uncooked vegetables
- Make sure the food is cooked
- Make sure the water is clogged or boiled and you can consume
- Avoid street foods as this can lead to cholera and other diseases
- Travelers should inquire about cholera before visiting a country where it prevails.
- People should seek immediate medical attention if they experience symptoms such as leg cramps, vomiting and diarrhea in a community where the disease exists.
Vaccine Against Cholera
There are currently three cholera vaccines recommended by the World Health Organization (WHO). These are Dukoral, Shanchol and Euvichol.
All three require two doses to give complete protection.
Dukoral must be taken with clean water, and it provides about 65 percent protection for 2 years.
Shanchol and Euvichol do not need to be taken with water, and they provide 65 percent protection for 5 years. All vaccines offer superior protection closer to the time they are given