Cholera

A devastating and sometimes lethal disease with intense vomiting and profuse watery diarrhea leading to dehydration which, unless immediately treated, may be fatal. Cholera was discovered in 1883 to be due to infection with Vibrio cholerae, a comma-shaped bacteria. The discovery was made by the great German bacteriologist Robert Koch (1843-1910). As head of a commission investigating the disease, Koch went to Egypt where an epidemic was taking place and there he found some sort of bacterium in the intestines of those dead of cholera but could neither isolate the organism nor infect animals with it. Later in 1883 Koch went to India, where he wrote that he succeeded in isolating "a little bent [bacilli], like a comma." He discovered that the bacteria thrived in damp dirty linen and moist earth and in the stools of patients with the disease. The key to treating cholera is prompt and complete replacement of the fluid and salt lost through the profuse diarrhea. Patients are rehydrated with an oral solution which is a prepackaged mixture of sugar and salts that is then mixed with water and drunk in large amounts. With prompt and complete oral rehydration, fewer than 1% of cholera patients now die. Very severe cases of cholera, especially those in which oral rehydration was not started in time, may also require intravenous fluid replacement. Antibiotics do shorten the course and diminish the severity of the illness, but they are not as important as rehydration. Thanks to modern sanitary practices, cholera is no longer as common as it once was, but it remains a global health threat. Epidemics will occur whenever people live in unsanitary crowded conditions, as in refuge camps. At the turn of the new millennium, epidemics of cholera were reported in Madagascar, Somalia, and Mecca. After a group of French Moslems returned from the Haj pilgrimage to Mecca, they came down with cholera. French health authorities found traces of cholera in 2,700 liters (700 gallons) of water they had brought back to France in barrels. The water was for distribution to members of the Moslem community who were unable to go to Mecca for the annual pilgrimage. The genes of cholera: The entire genetic information of an organism is scientifically referred to as its genome. The genome of Vibrio cholera was fully sequenced in the year 2000. It has over 4 million bases in its DNA with sequences for nearly 4,000 genes. The genome is remarkable in that it is arranged in two circular chromosomes. The larger of the two chromosomes has the usual "housekeeping" genes possessed by many organisms, while the smaller chromosome contains the genetic elements that make the bacteria pathogenic (capable of causing disease). Like other Vibrio, Vibrio cholerae moves about actively. The word “vibrio” in Latin means “to quiver.” Cholera is sometimes called Asian cholera although Asia has no monopoly on Vibrio cholerae.

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An acute epidemic infectious disease caused by the bacterium Vibrio cholerae. A soluble toxin elaborated in the intestinal tract by the bacterium activates the adenylate cylase of the mucosa, causing active secretion of an isotonic fluid resulting in profuse watery diarrhea, extreme loss of fluid and electrolytes, and dehydration and collapse, but no gross morphologic change in the intestinal mucosa. SYN: Asiatic c.. [L. a bilious disease, fr. G. chole, bile]

- Asiatic c. SYN: c..

- c. infantum old term for a disease of infants, characterized by vomiting, profuse watery diarrhea, fever, prostration, and collapse.

- c. morbus old term for acute severe gastroenteritis of unknown etiology, marked by severe colic, vomiting, and diarrhea with watery stools; formerly common during hot weather.

- pancreatic c. SYN: diarrhea pancreatica.

- c. sicca an old term for a malignant form of disease seen during epidemics of Asiatic c. in which death occurs without diarrhea.

- typhoid c. old term for c. (2) with predominantly cerebral manifestations such as confusion or dementia.

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chol·era 'käl-ə-rə n any of several diseases of humans and domestic animals usu. marked by severe gastrointestinal symptoms: as

a) an acute diarrheal disease caused by an enterotoxin produced by various strains of a comma-shaped gram-negative bacterium of the genus Vibrio (V. cholerae syn. V. comma) when it is present in large numbers in the proximal part of the human small intestine see ASIATIC CHOLERA

b) FOWL CHOLERA

c) HOG CHOLERA

chol·e·ra·ic .käl-ə-'rā-ik adj

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n.

an acute infection of the small intestine by the bacterium Vibrio cholerae, which causes severe vomiting and diarrhoea (known as ricewater stools) leading to dehydration. The disease is contracted from food or drinking water contaminated by faeces from a patient. Cholera often occurs in epidemics; outbreaks are rare in good sanitary conditions. After an incubation period of 1-5 days symptoms commence suddenly; the resulting dehydration and the imbalance in the concentration of body fluids can cause death within 24 hours. Initial treatment involves replacing the fluid loss by oral rehydration therapy; tetracycline eradicates the bacteria and hastens recovery. The mortality rate in untreated cases is over 50%. Vaccination against cholera is effective for only 6-9 months.

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chol·era (kolґər-ə) [Gr., from cholē bile] 1. an acute infectious, sometimes fulminant, enteritis endemic in India and Southeast Asia and periodically spreading in epidemics or pandemics to other warm regions of the world; it is spread by feces-contaminated water and food. The cause is a potent enterotoxin called a choleragen, elaborated by Vibrio cholerae, that acts on epithelial cells in the small intestine to cause copious secretion of isotonic fluid from the mucosal surface. Severe cases are marked by painless watery diarrhea called rice-water stools, which are diagnostic and result in massive fluid loss, saline depletion, acidosis, and shock that can be fatal. 2. any of several infections that resemble this disease, particularly in veterinary medicine, but are not caused by Vibrio cholerae. choleraic adj