It is a disease of bacterial origin that causes severe diarrhea – the infecting bacterium being Vibrio cholerae. All people infected by Vibrio cholera do not get the disease but the organism is present in their stools from 7th to 14th day of infection. Thus they can pass on the disease to others without suffering from the disease.
The bacterium has two life cycles. One is in the environment and the other in humans. They are attached to small crustaceans attached to algae in oceans. They are transmitted throughout the world as the crustaceans travel for food. With high temperatures in summer planktons and algae grow and the bacteria also grow and cause out break. Sporadic cases of cholera also come across through the world.
Cholera is caused by ingestion of food or water contaminated by Vibrio cholera. Uncooked fruits and vegetables, raw shellfish or other foods can harbor these bacteria. The disease is caused due to crowded living and inadequate sanitation facilities especially after natural calamities or war. The infection can spread through well water, eating raw seafood especially shellfish, raw fruits and vegetables and cooked food kept at room temperature for longer time.
Diarrhea is caused due to the production of toxin (toxin CTX) by the cholera bacteria in the intestine which causes loss of fluids and electrolytes from the body. Cholera is prevalent in Middle East, Asia, India, sub Saharan Africa and Latin America.
Anybody can contract cholera. However, people having reduced secretion of gastric acid (hypochlorhydria), malnourished individuals, eating raw or under cooked shellfish, individuals with blood group O, immuno-compromised persons and people nursing a cholera patient at home are at higher risk of cholera disease.
The period from infection until symptoms occur in cholera is usually 18–72 hours. Most of the people infected by the bacterium have mild to moderate symptoms and hence often it is difficult to distinguish cholera from other diarrhea. Only 10 percent of the infected people show classical symptoms of cholera.
The symptoms are seen between one to five days after infection. The symptoms are nausea, vomiting, severe diarrhea, watery stool, dehydration, muscles cramps and shock. Diarrhea is large with mucus and is pale milky. Rice water stool is the characteristic of cholera. Dehydration develops fast (in few hours) as compared to other diarrheas.
Symptoms of dehydration are sunken eyes, lethargy, dry mouth, dry skin, extreme thirst, irritability, low blood pressure and irregular heartbeats. In children, along with the symptoms seen in adults, fever, convulsion, tremendous tiredness or coma may be seen.
Cholera is an easily treatable disease. The patients get dehydrated due to disease but can be re-hydrated by easy and low-cost re-hydrating solutions called as ORS, oral rehydrating solution. Cholera requires immediate treatment. Further all the diarrheas are treated along the same line of treatment. Therefore rehydration has to be immediately started before the results of the tests. Generally rehydration is done by oral liquids but in severe cases fluids are given intravenously. Antibiotics may also be given. Blood pressure, blood sugar, electrolyte levels, blood oxygen and carbon dioxide levels and pulse are regularly monitored.
With immediate treatment there is a complete recovery. In severe cases due to quick loss of electrolytes and fluids, if treatment is not given death can occur in 2-3 hours. In less severe situations without treatment death may occur in 18-48 hours.
If the disease is not treated then it can cause death in a few hours. Due to reduced blood volume, blood pressure drops and due to inadequate oxygen supply to various organs causes hypoyolemic shock. This may cause death in minutes also.
If diarrhea is severe accompanied by dehydration then it should be treated as emergency and doctor should be immediately contacted. Less serious complications may be low blood sugar and potassium level and renal failure.
Adequate hygiene practices help in prevention of cholera. Eating cooked and hot food, avoiding untreated water and unpasteurized milk and milk products and cleaning hands, fruits and vegetables help in preventing cholera. Precautions should be taken especially while traveling.
