Cholera (or Asiatic cholera or epidemic cholera) is a severe diarrheal disease caused by the bacterium Vibrio cholerae.

Symptoms
In general, patients must receive as much fluid as they lose, which can be up to 36 L, due to diarrhea.
Treatment typically consists of aggressive rehydration (restoring the lost body fluids) and replacement of electrolytes with commercial or hand-mixed sugar-salt solutions (1 tsp salt + 8 tsp sugar in 1 litre of clean/boiled water) or massive injections of liquid given intravenously via an IV in advanced cases. See: Oral rehydration therapy for easily made rehydration solutions and Ceralyte. Without rehydration, the death rate can be as high as (10-50%) due to the serious dehydration that cholera produces.
Tetracycline antibiotics may have a role in reducing the duration and severity of cholera, although drug-resistance is occurring.

Treatment

Epidemiology
Although cholera can be life-threatening, it is nearly always easily prevented, in principle, if proper sanitation practices are followed. In the United States and Western Europe, because of advanced water treatment and sanitation systems, cholera is no longer a major threat. The last major outbreak of cholera in the United States was in 1911. However, everyone, especially travelers, should be aware of how the disease is transmitted and what can be done to prevent it. Good sanitation practices, if instituted in time, is usually sufficient to stop an epidemic. There are several points along the transmission path at which the spread may be halted:

Sickbed: Proper disposal and treatment of the germ infected fecal waste (and all clothing and bedding that come in contact with it) produced by cholera victims is of primary importance.
Sewage: Treatment of general sewage before it enters the waterways or underground water supplies prevent possible undetected patients from spreading the disease.
Sources: Warnings about cholera contamination posted around contaminated water sources with directions on how to decontaminate the water.
Sterilization: Boiling, filtering, and chlorination of water kill the bacteria produced by cholera patients and prevent infections, when they do occur, from spreading. All materials (clothing, bedding, etc.) that come in contact with cholera patients should be sterilized in hot water using (if possible) chlorine bleach. Hands, etc. that touch cholera patients or their clothing etc. should be thoroughly cleaned and sterilized. All water used for drinking, washing or cooking should be sterilized by boiling or chlorination in any area where cholera may be present. Water filtration, chlorination and boiling are by far the most effective means of halting transmission. Cloth filters, though very basic, have greatly reduced the occurrence of cholera when used in poor villages in Bangladesh that rely on untreated surface water. In general, public health education and good sanitation practices are the limiting factors in preventing transmission. Prevention
Recent epidemiologic research suggests that an individual's susceptibility to cholera (and other diarrheal infections) is affected by their blood type: Those with type O blood are the most susceptible, In this model, the genetic deficiency in the cystic fibrosis transmembrane conductance regulator channel proteins interferes with bacteria binding to the gastrointestinal epithelium, thus reducing the effects of an infection.

Susceptibility
Persons infected with cholera have massive diarrhea. This highly liquid diarrhea, which is often compared to "rice water," is loaded with bacteria that can spread under unsanitary conditions to infect water used by other people. Cholera is transmitted from person to person through ingestion of feces contaminated water loaded with the cholera bacterium. The source of the contamination is typically other cholera patients when their untreated diarrhea discharge is allowed to get into waterways or into groundwater or drinking water supply. Any infected water and any foods washed in the water, and shellfish living in the affected waterway can cause an infection. Cholera is rarely spread directly from person to person. V. cholerae occurs naturally in the plankton of fresh, brackish, and salt water, attached primarily to copepods in the zooplankton. Both toxic and non-toxic strains exist. Non-toxic strains can acquire toxicity through a lysogenic bacteriophage. Coastal cholera outbreaks typically follow zooplankton blooms. This makes cholera a zoonosis.

Transmission
Stool and Swab collected in the acute stage of the disease is useful specimen for laboratory diagnosis. A number of special media have been employed for the cultivation for cholera vibrios. They are classified as follows:

Laboratory Diagnosis

Venkataraman-ramakrishnan (VR) medium
Cary-Blair medium: This the most popularly carrying media. This is a buffered solution of sodium chloride, sodium thioglycollate, disodium phosphate and calcium chloride at pH 8.4. Holding or transport media

Alkaline peptone water
Monsur's taurocholate tellurite peptone water Enrichment media

Alkaline bile salt agar: The colonies are very similar to those on Nutrient Agar.
Monsur's gelatin Tauro cholate trypticase tellurite agar(GTTA)medium: Cholera vibrios produce small translucent colonies with a greyish black centre .
TCBS meium: This the mostly widely used medium. This medium contains Thiosulphate, citrate, bile salts and sucrose. Cholera vibrios produce Flat 2-3 mm in diameter, yellow nucleated colonies. Plating media
Most of the V. cholerae bacteria in the contaminated water that a potential host drinks do not survive the very acidic conditions of the human stomach

Biochemistry of the V. cholerae bacterium

History
Cholera was originally endemic to the Indian subcontinent, with the Ganges River likely serving as a contamination reservoir. It spread by trade routes (land and sea) to Russia, then to Western Europe, and from Europe to North America. It is now no longer considered an issue in Europe and North America, due to filtering and chlorination of the water supply.

1816-1826 - First Cholera pandemic: Previously restricted, the pandemic began in Bengal, then spread across India by 1820. It extended as far as China and the Caspian Sea before receding.
1829-1851 - Second Cholera pandemic reached Europe, London and Paris in 1832. In London, it claimed 6,536 victims (see: http://www.mernick.co.uk/thhol/1832chol.html); in Paris, 20,000 succumbed (out of a population of 650,000) with about 100,000 deaths in all of France [4]. It reached Russia (Cholera Riots), Quebec, Ontario and New York in the same year and the Pacific coast of North America by 1834.
1849 - Second major outbreak in Paris. In London, it was the worst outbreak in the city's history, claiming 14,137 lives, ten times as many as the 1832 outbreak. In 1849 cholera claimed 5,308 lives in the port city of Liverpool, England, and 1,834 in Hull, England.
1881-1896 - Fifth Cholera pandemic ; The 1892 outbreak in Hamburg, Germany was the only major European outbreak; about 8,600 people died in Hamburg, causing a major political upheaval in Germany, as control over the City was removed from a City Council which had not updated Hamburg's water supplies. This was the last serious European cholera outbreak.
1899-1923 - Sixth Cholera pandemic had little effect in Europe because of advances in public health, but Russia was badly affected again.
1961-1970s - Seventh Cholera pandemic began in Indonesia, called El Tor after the strain, and reached Bangladesh in 1963, India in 1964, and the USSR in 1966. From North Africa it spread into Italy by 1973. In the late 1970s there were small outbreaks in Japan and in the South Pacific. There were also many reports of a cholera outbreak near Baku in 1972, but information of this was suppressed in the USSR.
January 1991 to September 1994 - Outbreak in South America, apparently initiated by ship discharged ballast water. Beginning in Peru there were 1.04 million identified cases and almost 10,000 deaths. The causative agent was an O1, El Tor strain, with small differences to the seventh pandemic strain. In 1992 a new strain appeared in Asia, a non-O1, nonagglutinable vibrio (NAG) named O139 Bengal. It was first identified in Tamil Nadu, India and for a while displaced El Tor in southern Asia before decreasing in prevalence from 1995 to around 10% of all cases. It is considered to be an intermediate between El Tor and the classic strain and occurs in a new serogroup. There is evidence as to the emergence of wide-spectrum resistance to drugs such as trimethoprim, sulfamethoxazole and streptomycin. Origin and Spread
The crying and pathos in the last movement of Tchaikovsky's (c. 1840-1893) last symphony made people think that Tchaikovsky had a premonition of death. "A week after the premiere of his Sixth Symphony, Tchaikovsky was dead--6 Nov. 1893. The cause of this indisposition and stomach ache was suspected to be his intentionally infecting himself with cholera by drinking contaminated water. The day before while having lunch with Modest (his brother and biographer), he is said to have poured faucet water from a pitcher into his glass and drunk a few swallows. Since the water was not boiled and cholera was once again rampaging St. Petersburg, such a connection was quite plausible ...."
Other famous people who succumbed to the disease include:
Alexandre Dumas, père, French author of The Three Musketeers and The Count of Monte Cristo, also contracted cholera in the 1832 Paris epidemic and almost died, before he wrote these two novels.

James K. Polk ex-President of the United States
Mary Abigail Fillmore, daughter of U.S. president Millard Fillmore
Elliott Frost, son of American poet Robert Frost
Nicolas Léonard Sadi Carnot
Georg Wilhelm Friedrich Hegel
Samuel Charles Stowe, son of Harriet Beecher Stowe
Carl von Clausewitz
George Bradshaw
Adam Mickiewicz
August von Gneisenau
William Jenkins Worth
John Blake Dillon
Daniel Morgan Boone, founder of Kansas City, Missouri, son of Daniel Boone
James Clarence Mangan
Mohammad Ali Mirza Dowlatshahi of Persia
Ando Hiroshige, Japanese ukiyo-e woodblock print artist.
Juan de Veramendi, Mexican Governor of Texas, father-in-law of Jim Bowie
Grand Duke Constantine Pavlovich of Russia
William Shelley, son of Mary Shelley
William Godwin, father of Mary Shelley
Judge Daniel Stanton Bacon, father-in-law of George Armstrong Custer
Inessa Armand, mistress of Lenin and the mother of Andre, his son.
Honinbo Shusaku, famous go player renowned for his play.
Henry Louis Vivian Derozio, Eurasian Portuguese Poet and Teacher. Resided in India. Famous cholera victims
The major contributions to fighting cholera were made by physician and self-trained scientist John Snow (1813-1858), who found the link between cholera and contaminated drinking water in 1854 and Henry Whitehead, an Anglican minister, who helped John Snow track down and verify the source of the disease, an infected well in London. Their conclusions and writings were widely distributed and firmly established for the first time a definite link between germs and disease. Clean water and good sewage treatment, despite their major engineering and financial cost, slowly became a priority throughout the major developed cities in the world from this time onward. Robert Koch, 30 years later, identified V. cholerae with a microscope as the bacillus causing the disease in 1885. The bacterium had been originally isolated thirty years earlier (1855) by Italian anatomist Filippo Pacini, but its exact nature and his results were not widely known around the world.
Cholera has been a laboratory for the study of evolution of virulence. The province of Bengal in British India was partitioned into West Bengal (a state in India) and East Pakistan in 1947. Prior to partition, both regions had cholera pathogens with similar characteristics. After 1947, India made more progress on public health than East Pakistan (now Bangladesh). As a consequence, the strains of the pathogen which succeeded in India had a greater incentive in the longevity of the host and are less virulent than the strains prevailing in Bangladesh, which uninhibitedly draw upon the resources of the host population, thus rapidly killing many in it.

Research
In the past, people travelling in ships would hang a yellow flag if one or more of the crew members suffered from cholera. Boats with a yellow flag hung would not be allowed to disembark at any harbor for an extended period of time, typically 30 to 40 days.