A bacterium called Vibrio cholerae causes cholera infection. The deadly effects of the disease are the result of a toxin the bacteria produces in the small intestine. The toxin causes the body to secrete enormous amounts of water, leading to diarrhea and a rapid loss of fluids and salts (electrolytes).
Cholera bacteria might not cause illness in all people who are exposed to them, but they still pass the bacteria in their stool, which can contaminate food and water supplies.
Contaminated water supplies are the main source of cholera infection. The bacterium can be found in:
▪️Surface or well water.
▪️Seafood.
▪️Raw fruits and vegetables. Raw, unpeeled fruits and vegetables are a frequent source of cholera infection in areas where uncomposted manure fertilizers or irrigation water containing raw sewage can contaminate produce in the field.
▪️Grains. In regions where cholera is widespread, grains that are contaminated after cooking and kept at room temperature for several hours can grow cholera bacteria.
Everyone is susceptible to cholera, with the exception of infants who get immunity from nursing mothers who have previously had cholera. Still, certain factors can make you more vulnerable to the disease or more likely to have severe signs and symptoms.
Risk factors for cholera include:
▪️Poor sanitary conditions.
▪️Reduced or nonexistent stomach acid.
▪️Household exposure. You're at increased risk of cholera if you live with someone who has the disease.
▪️Type O blood. For reasons that aren't entirely clear, people with type O blood are twice as likely to develop cholera compared with people with other blood types.
▪️Raw or undercooked shellfish.
Although shock and severe dehydration are the worst complications of cholera, other problems can occur, such as:
▪️Low blood sugar
▪️Low potassium levels
▪️Kidney failure
Cholera can quickly become fatal. In the most severe cases, the rapid loss of large amounts of fluids and electrolytes can lead to death within hours. In less extreme situations, people who don't receive treatment can die of dehydration and shock hours to days after cholera symptoms first appear.
In 1849, English doctor John Snow proposed that cholera was spread by contaminated water. He rejected the commonly held idea that “bad air,” or miasma, was responsible for cholera. Rather, based on his careful examination of a London outbreak, he suggested that the disease occurred when people ingested certain tiny particles in water.
In 1854, Italian physician Filippo Pacini linked the cholera bacterium to the disease itself. Pacini microscopically observed samples from the intestines of cholera victims and noted the presence of tiny, comma-shaped particles that he suggested were the cause of the disease. He suggested that the cholera vibrio acted on the lining of the intestine to cause massive fluid and electrolyte loss, and he suggested that cholera patients be treated with intravenous injections of water to which salt had been added. Though most of his ideas have been shown to be correct, the scientific world largely ignored his work during his lifetime.
In 1885, Spanish physician Jaime Ferrán developed a live, attenuated cholera vaccine. His vaccine was the first to immunize humans against a bacterial disease. He created the vaccine by cultivating bacteria taken from the waste of a person ill with cholera and growing the bacteria on nutrient culture at room temperature. The material was then administered to subjects via one to three injections in the arm. During the rest of his career, Ferrán would develop vaccines for plague, tetanus, typhus, tuberculosis, and rabies.
In 1896, Wilhelm Kolle developed a heat-inactivated cholera vaccine that came to serve as a model for cholera vaccines for the next century.
In 1927, Alexandre Besredka developed a vaccine for cholera known as a bilivaccine, which used bile salts. It was the first oral vaccine developed. Besredka’s bilivaccine was given in doses on three successive days and consisted of a bile tablet followed by a tablet containing cholera vibrios.
In the United States, an oral cholera vaccine (Vaxchora®) is approved for adults age 18-64 traveling to cholera-afflicted areas. Other cholera vaccines are currently in the development pipeline.
{You can find all the sources I used by clicking here.}
No comments:
Post a Comment