Cholera, sometimes known as
Asiatic or
epidemic cholera, is an infectious
gastroenteritisGastroenteritis is inflammation of the gastrointestinal tract, involving both the stomach and the small intestine and resulting in acute diarrhea...
caused by
enterotoxinAn enterotoxin is a protein toxin released by a microorganism in the intestine.Enterotoxins are chromosomally encoded exotoxins that are produced and secreted from several bacterial organisms. They are often heat stable, of low molecular weight and are water-soluble...
-producing strains of the bacterium
Vibrio choleraeVibrio cholerae is a motile gram negative curved-rod shaped bacterium with a polar flagellum that causes cholera in humans. V. cholerae and other species of the genus Vibrio belong to the gamma subdivision of the Proteobacteria. There are two major strains of V. cholerae, classic and El Tor,...
. Transmission to humans occurs through eating food or drinking water contaminated with
Vibrio cholerae from other cholera patients. The major reservoir for cholera was long assumed to be humans themselves, but considerable evidence exists that aquatic environments can serve as reservoirs of the bacteria.
Vibrio cholerae is a
Gram-negativeGram-negative bacteria are those bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color...
bacterium that produces
cholera toxinCholera toxin is a protein complex secreted by the bacterium Vibrio cholerae. CTX is responsible for the harmful effects of cholera infection.- Structure :...
, an
enterotoxinAn enterotoxin is a protein toxin released by a microorganism in the intestine.Enterotoxins are chromosomally encoded exotoxins that are produced and secreted from several bacterial organisms. They are often heat stable, of low molecular weight and are water-soluble...
, whose action on the mucosal
epitheliumIn biology and medicine, an epithelium is a tissue composed of cells that line the cavities and surfaces of structures throughout the body. Many glands are also formed from epithelial tissue...
lining of the
small intestineIn vertebrates, the small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where the vast majority of digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large...
is responsible for the disease's most salient characteristic, exhaustive
diarrheaIn medicine, diarrhea , also spelled diarrhoea , is the condition of having frequent loose or liquid bowel movements. Acute diarrhea is a common cause of death in developing countries and the second most common cause of infant deaths worldwide...
. In its most severe forms, cholera is one of the most rapidly fatal illnesses known, and a healthy person's
blood pressureBlood pressure is the pressure exerted by circulating blood on the walls of blood vessels, and is one of the principal vital signs. During each heartbeat, BP varies between a maximum and a minimum pressure...
may drop to
hypotensiveIn physiology and medicine, hypotension refers to an abnormally low blood pressure. This is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the opposite of hypertension, which is high blood...
levels within an hour of the onset of symptoms; infected patients may die within three hours if medical treatment is not provided. In a common scenario, the disease progresses from the first
liquidLiquid is one of the principal states of matter. A liquid is a fluid that has the particles loose and can freely form a distinct surface at the boundaries of its bulk material. The surface is a free surface where the liquid is not constrained by a container....
stoolHuman Feces , also known as stools, is the waste product of the human digestive system and varies significantly in appearance, depending on the state of the whole digestive system, influenced and found by diet and health.Normally stools are semisolid, with a mucus coating...
to shock in 4 to 12 hours, with death following in 18 hours to several days, unless oral (or, in more serious cases, intravenous)
rehydration therapyOral rehydration therapy is a simple, cheap, and effective treatment for dehydration associated with diarrhea, particularly gastroenteritis, such as that caused by cholera or rotavirus. ORT consists of a solution of salts and sugars which is taken by mouth...
is provided.
The majority of reported gross cholera cases worldwide occur in
AfricaAfrica is the world's second-largest and second most-populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area. With a billion people in 61 territories, it accounts for about 14.8% of the...
. It is estimated that most cases of cholera are unreported due to poor surveillance systems, particularly in Africa. Fatality rates are 5% of total cases in Africa, and less than 1% elsewhere. For a map of recent international outbreaks, see:
http://www.who.int/entity/cholera/countries/WorldOutbreaksMap2008.PNG
Treatment
In most cases cholera can be successfully treated with oral rehydration therapy. Prompt replacement of water and electrolytes is the principal treatment for cholera, as
dehydrationDehydration is defined as excessive loss of body water. It is literally the removal of water from an object. In physiological terms, it entails a relative deficiency of water molecules in relation to other dissolved solutes...
and electrolyte depletion occur rapidly.
Oral rehydration therapyOral rehydration therapy is a simple, cheap, and effective treatment for dehydration associated with diarrhea, particularly gastroenteritis, such as that caused by cholera or rotavirus. ORT consists of a solution of salts and sugars which is taken by mouth...
or ORT is highly effective, safe, and simple to administer. In situations where commercially produced ORT sachets are too expensive or difficult to obtain, alternative homemade solutions using various formulas of water, sugar, table salt, baking soda, and fruit offer less expensive methods of electrolyte repletion (i.e. Gatorade or Powerade). In severe cholera cases with significant dehydration, the administration of intravenous rehydration solutions may be necessary.
Antibiotics shorten the course of the disease, and reduce the severity of the symptoms. However
Oral rehydration therapyOral rehydration therapy is a simple, cheap, and effective treatment for dehydration associated with diarrhea, particularly gastroenteritis, such as that caused by cholera or rotavirus. ORT consists of a solution of salts and sugars which is taken by mouth...
remains the principal treatment.
TetracyclineTetracycline is a broad-spectrum polyketide antibiotic produced by the Streptomyces genus of Actinobacteria, indicated for use against many bacterial infections. It is a protein synthesis inhibitor. It is commonly used to treat acne today, and more recently, rosacea, and played a historical role...
is typically used as the primary antibiotic, although some strains of
V. cholerae exist that have shown resistance. Other antibiotics that have been proven effective against
V. cholerae include cotrimoxazole,
erythromycinErythromycin is a macrolide antibiotic that has an antimicrobial spectrum similar to or slightly wider than that of penicillin, and is often used for people who have an allergy to penicillins. For respiratory tract infections, it has better coverage of atypical organisms, including mycoplasma and...
,
doxycyclineDoxycycline is a member of the tetracycline antibiotics group and is commonly used to treat a variety of infections. Doxycycline is a semi-synthetic tetracycline invented and clinically developed in the early 1960s by Pfizer Inc. and marketed under the brand name Vibramycin. Vibramycin received...
,
chloramphenicolChloramphenicol is a bacteriostatic antimicrobial originally derived from the bacterium Streptomyces venezuelae, isolated by David Gottlieb, and introduced into clinical practice in 1949...
, and
furazolidoneFurazolidone is an antibacterial. It is marketed by Roberts Laboratories under the brand name Furoxone and by GlaxoSmithKline as Dependal-M.-Uses:It is used to treat diarrhoea and enteritis caused by bacteria or protozoan infections....
. Fluoroquinolones such as
norfloxacinNorfloxacin is a synthetic chemotherapeutic agent occasionally used to treat common as well as complicated urinary tract infections. It is sold under various brand names with the most common being Noroxin. In form of ophthalmic solutions it is known as Chibroxin. Norfloxacin is a second generation...
also may be used, but resistance has been reported.
Rapid diagnostic assay methods are available for the identification of multidrug resistant
V. cholerae. New generation antimicrobials have been discovered which are effective against
V. cholerae in
in vitro studies.
The success of treatment is significantly affected by the speed and method of treatment. If cholera patients are treated quickly and properly, the mortality rate is less than 1%; however, with untreated cholera the mortality rate rises to 50–60%.
Prevention
Although cholera may be life-threatening, prevention of the disease is normally straightforward if proper sanitation practices are followed. In the
first worldThe terms First World, Second World, and Third World were used to divide nations into three broad categories. The three terms did not arise simultaneously. After World War II, people began to speak of the NATO and Warsaw Pact countries as two major blocs, often using such terms as the "Western...
, due to nearly universal advanced
water treatmentWater treatment describes those processes used to make water more acceptable for a desired end-use. These can include use as drinking water, industrial processes, medical and many other uses. The goal of all water treatment process is to remove existing contaminants in the water, or reduce the...
and sanitation practices, cholera is no longer a major health threat. The last major outbreak of cholera in the United States occurred in 1910-1911. Travelers should be aware of how the disease is transmitted and what can be done to prevent it. Effective sanitation practices, if instituted and adhered to in time, are usually sufficient to stop an epidemic. There are several points along the cholera transmission path at which its spread may be (and should be) halted:
- Sterilization: Proper disposal and treatment of infected fecal waste water produced by cholera victims and all contaminated materials (e.g. clothing, bedding, etc) is essential. All materials that come in contact with cholera patients should be sterilized
Sterilization refers to any process that effectively kills or eliminates transmissible agents from a surface, equipment, article of food or medication, or biological culture medium. Sterilization does not, however, remove prions...
by washing in hot water using chlorineChlorine Chlorine Chlorine ( , from the Greek word 'χλωρóς' (khlôros, meaning 'pale green'), is the chemical element with atomic number 17 and symbol Cl. It is a halogen, found in the periodic table in group 17 (formerly VII, VIIa, or VIIb). As the chloride ion, which is part of common salt and...
bleachA bleach is a chemical that removes colors or whitens, often via oxidation. Common chemical bleaches include household "chlorine bleach", a solution of approximately 3–6% sodium hypochlorite , and "oxygen bleach", which contains hydrogen peroxide or a peroxide-releasing compound such as sodium...
if possible. Hands that touch cholera patients or their clothing, bedding, etc, should be thoroughly cleaned and sterilized with chlorinated water or other effective anti-microbial agents.
- Sewage: anti-bacterial treatment of general sewage
Sewage is water-carried wastes, in either solution or suspension, that flow away from a community. Also known as wastewater flows, sewage is the used water supply of the community. It is more than 99.9% pure water and is characterized by its volume or rate of flow, its physical condition, its...
by chlorine, ozone, ultra-violet light or other effective treatment before it enters the waterways or underground water supplies helps prevent undiagnosed patients from inadvertently spreading the disease.
- Sources: Warnings about possible cholera contamination should be posted around contaminated water sources with directions on how to decontaminate
Decontamination is the process of cleansing to remove contamination, or the possibility of contamination. Decontamination is sometimes abbreviated as "decon", "dcon", or "decontam"....
the water (boiling, chlorination etc.) for possible use.
- Water purification: All water used for drinking, washing, or cooking should be sterilized by either boiling, chlorination
Chlorination is the process of adding the element chlorine to water as a method of water purification to make it fit for human consumption as drinking water...
, ozone water treatment, ultra-violet light sterilization, or anti-microbal filtration in any area where cholera may be present. Chlorination and boiling are often the least expensive and most effective means of halting transmission. Cloth filterDeveloped for use in Bangladesh, the cloth filter is a simple and cost-effective appropriate technology method for reducing the contamination of drinking water...
s, though very basic, have significantly reduced the occurrence of cholera when used in poor villages in Bangladesh, officially the People's Republic of Bangladesh is a country in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...
that rely on untreated surface water. Better anti-microbal filters like those present in advanced individual water treatment hiking kits are most effective. Public health education and adherence to appropriate sanitation practices are of primary importance to help prevent and control transmission of cholera and other diseases.
A vaccine for cholera is available in some countries, but prophylactic usage is not currently recommended for routine use by the
Centers for Disease Control and PreventionThe Centers for Disease Control and Prevention is a United States federal agency under the Department of Health and Human Services based in Atlanta, Georgia. It works to protect public health and safety by providing information to enhance health decisions, and it promotes health through...
(CDC). During recent years, substantial progress has been made in developing new oral vaccines against cholera. Two oral cholera vaccines, which have been evaluated with volunteers from industrialized countries and in regions with endemic cholera, are commercially available in several countries: a killed whole-cell
V. cholerae O1 in combination with purified recombinant B subunit of cholera toxin and a live-attenuated live oral cholera vaccine, containing the genetically manipulated
V. cholerae O1 strain CVD 103-HgR. The appearance of
V. cholerae O139 has influenced efforts in order to develop an effective and practical cholera vaccine since none of the currently available vaccines is effective against this strain.
The newer vaccine (brand name:
DukoralDukoral is a vaccine against cholera and traveler's diarrhea.It is largely used by backpackers and persons visiting locations where there is a high risk of cholera infection...
), an orally administered inactivated whole cell vaccine, appears to provide somewhat better immunity and have fewer adverse effects than the previously available vaccine. This safe and effective vaccine is available for use by individuals and health personnel. Work is under way to investigate the role of mass vaccination.
Sensitive surveillance and prompt reporting allow for containing cholera epidemics rapidly. Cholera exists as a seasonal disease in many endemic countries, occurring annually mostly during rainy seasons. Surveillance systems can provide early alerts to outbreaks, therefore leading to coordinated response and assist in preparation of preparedness plans. Efficient surveillance systems can also improve the risk assessment for potential cholera outbreaks. Understanding the seasonality and location of outbreaks provide guidance for improving cholera control activities for the most vulnerable. This will also aid in the developing indicators for appropriate use of oral cholera vaccine.
Susceptibility
Recent
epidemiologic researchEpidemiology is the study of factors affecting the health and illness of populations, and serves as the foundation and logic of interventions made in the interest of public health and preventive medicine...
suggests that an individual's susceptibility to cholera (and other diarrheal infections) is affected by their
blood typeA blood type is a classification of blood based on the presence or absence of inherited antigenic substances on the surface of red blood cells...
: those with type O blood are the most susceptible, while those with type AB are the most resistant. Between these two extremes are the A and B blood types, with type A being more resistant than type B.
About one million
V. cholerae bacteria must typically be ingested to cause cholera in normally healthy adults, although increased susceptibility may be observed in those with a weakened
immune systemAn immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumour cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
, individuals with decreased gastric acidity (as from the use of
antacidAn antacid is any substance, generally a base or basic salt, which counteracts stomach acidity. In other words, antacids are stomach acid neutralizers.-Action mechanism:...
s), or those who are
malnourishedMalnutrition is the insufficient, excessive or imbalanced consumption of nutrients.A number of different nutrition disorders may arise, depending on which nutrients are under or overabundant in the diet....
.
It has also been hypothesized that the
cystic fibrosisCystic fibrosis is a genetic disorder known to be an inherited disease of the secretory glands, including the glands that make mucus and sweat....
genetic
mutationIn biology, a mutation is a randomly derived change to the nucleotide sequence of the genetic material of an organism.Mutations can be caused by copying errors in the genetic material during cell division, or by exposure to mutagens , or can be induced by the organism itself, by cellular processes...
has been maintained in humans due to a selective advantage: heterozygous carriers of the mutation (who are thus not affected by cystic fibrosis) are more resistant to
V. cholerae infections. In this model, the genetic deficiency in the
cystic fibrosis transmembrane conductance regulatorCystic fibrosis transmembrane conductance regulator is an ABC transporter-class protein and ion channel that transports chloride ions across epithelial cell membranes...
channel proteins interferes with bacteria binding to the gastrointestinal epithelium, thus reducing the effects of an infection.
Transmission
People infected with cholera suffer acute diarrhea. This highly liquid diarrhea, colloquially referred to as "rice-water stool," is loaded with bacteria that can infect water used by other people. Cholera is transmitted from person to person through ingestion of water contaminated with the cholera bacterium, usually from faeces or other
effluentEffluent is an outflowing of water from a natural body of water, or from a man-made structure.Effluent in the man-made sense is generally considered to be water pollution, such as the outflow from a sewage treatment facility or the wastewater discharge from industrial facilities...
. The source of the contamination is typically other cholera patients when their untreated diarrhea discharge is allowed to get into waterways or into
groundwaterGroundwater is water located beneath the ground surface in soil pore spaces and in the fractures of lithologic formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in...
or drinking water supplies. Any infected water and any foods washed in the water, as well as
shellfishShellfish is a culinary and fisheries term for exoskeleton-bearing aquatic invertebrates used as food, including various species of molluscs, crustaceans, and echinoderms. Although most kinds of shellfish are harvested from saltwater environments, some kinds are found only in freshwater...
living in the affected
waterwayA waterway is any navigable body of water. These include rivers, lakes, seas, oceans, and canals. In order for a waterway to be navigable, it must meet several criteria:...
, can cause an infection. Cholera is rarely spread directly from person to person.
V. cholerae harbors naturally in the
zooplanktonZooplankton are the heterotrophic type of plankton. Plankton are organisms drifting in the water column of oceans, seas, and bodies of fresh water. The name of zooplankton is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
of
freshFresh Water is the debut album by Australian rock and blues singer Alison McCallum, released in 1972. Rare for an Australian artist at the time, it came in a gatefold sleeve...
,
brackishBrackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak," meaning "salten" or "salty"...
, and
salt waterSeawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5%. This means that every of seawater has approximately of dissolved salts...
, attached primarily to their chitinous
exoskeletonAn exoskeleton is an external skeleton that supports and protects an animal's body, in contrast to the internal endoskeleton of, for example, a human. Some animals, such as the tortoise, have both an endoskeleton and an exoskeleton...
. Both toxic and non-toxic strains exist. Non-toxic strains can acquire toxicity through a lysogenic
bacteriophageA bacteriophage is any one of a number of viruses that infect bacteria. Bacteriophages are among the most common organisms on Earth. The term is commonly used in its shortened form, phage....
. Coastal cholera outbreaks typically follow
zooplankton bloomsAn algal bloom is a rapid increase in the population of algae in an aquatic system. Algal blooms may occur in freshwater as well as marine environments. Typically, only one or a small number of phytoplankton species are involved, and some blooms may be recognized by discoloration of the water...
, thus making cholera a
zoonoticA zoonosis or zoonose is any infectious disease that can be transmitted from non-human animals, both wild and domestic, to humans or from humans to non-human animals...
disease.
Potential human contribution to transmissibility
Cholera bacteria grown
in vitro encounter difficulty subsequently growing in humans without additional stomach acid buffering. In a 2002 study at
Tufts University School of MedicineThe Tufts University School of Medicine is one of the eight schools that comprise Tufts University. Located on the university's health sciences campus in the Chinatown district of Boston, Massachusetts, the medical school has clinical affiliations with thousands of doctors and researchers in the...
, it was found that stomach acidity is a principal factor that contributes to epidemic spread. In their findings, the researchers found that human colonization creates a hyperinfectious bacterial state that is maintained after dissemination and that may contribute to epidemic spread of the disease. When these hyperinfectious bacteria underwent transcription profiles, they were found to possess a unique physiological and behavioral state, characterized by high expression levels of genes required for nutrient acquisition and motility, and low expression levels of genes required for bacterial chemotaxis. Thus, the spread of cholera can be expedited by host physiology.
Diagnosis
In epidemic situations a clinical diagnosis is made by taking a history of symptoms from the patient and by a brief examination only. Treatment is usually started without or before confirmation by laboratory analysis of specimens.
Stool and swab samples collected in the acute stage of the disease, before antibiotics have been administered, are the most useful specimens for laboratory diagnosis. If an epidemic of cholera is suspected, the most common causative agent is
Vibrio choleraeVibrio cholerae is a motile gram negative curved-rod shaped bacterium with a polar flagellum that causes cholera in humans. V. cholerae and other species of the genus Vibrio belong to the gamma subdivision of the Proteobacteria. There are two major strains of V. cholerae, classic and El Tor,...
O1. If
V. cholerae serogroup O1 is not isolated, the laboratory should test for
V. cholerae O139. However, if neither of these organisms is isolated, it is necessary to send stool specimens to a reference laboratory.
Infection with
V. cholerae O139 should be reported and handled in the same manner as that caused by
V. cholerae O1. The associated diarrheal illness should be referred to as cholera and must be reported as a case of cholera to the appropriate public health authorities.
A number of special media have been employed for the cultivation for cholera vibrios. They are classified as follows:
Holding or transport media
- Venkataraman-Ramakrishnan (VR) medium: This medium has 20g Sea Salt Powder and 5g Peptone dissolved in 1L of distilled water.
- Cary-Blair medium: This the most widely-used carrying media. This is a buffered solution of sodium chloride, sodium thioglycollate, disodium phosphate and calcium chloride at pH 8.4.
- Autoclaved sea water
Enrichment media
- Alkaline peptone water at pH 8.6
- Monsur's taurocholate tellurite peptone water at pH 9.2
Plating media
- Alkaline bile salt agar (BSA): The colonies are very similar to those on nutrient agar
Agar or agar agar is a gelatinous substance derived from seaweed. Historically and in a modern context, it is chiefly used as an ingredient in desserts throughout Japan, but in the past century has found extensive use as a solid substrate to contain culture medium for microbiological work...
.
- Monsur's gelatin Tauro cholate trypticase tellurite agar (GTTA) medium: Cholera vibrios produce small translucent colonies with a greyish black centre.
- TCBS medium: 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.
Direct
microscopyMicroscopy is the technical field of using microscopes to view samples or objects. There are three well-known branches of microscopy, optical, electron and scanning probe microscopy....
of stool is not recommended as it is unreliable. Microscopy is preferred only after enrichment, as this process reveals the characteristic motility of
Vibrios and its inhibition by appropriate
antiserumAntiserum is blood serum containing polyclonal antibodies. Antiserum is used to pass on passive immunity to many diseases. Passive antibody transfusion from a previous human survivor is the only effective treatment for Ebola infection....
. Diagnosis can be confirmed as well as serotyping done by
agglutinationIn linguistics, agglutination is the morphological process ofadding affixes to the base of a word. Languages that use agglutination widely are called agglutinative languages. These languages are often contrasted with fusional languages and isolating languages...
with specific sera.
Biochemistry
Most of the
V. cholerae bacteria in the contaminated water consumed by the host do not survive the highly acidic conditions of the
human stomachIn most mammals, the stomach is a hollow, muscular organ of the gastrointestinal tract , between the esophagus and the small intestine. It is involved in the second phase of digestion, following mastication . The word stomach is derived from the Latin stomachus, which derives from the Greek word...
. The few bacteria that do survive conserve their
energy and stored nutrientsA nutrient is a chemical that an organism needs to live and grow or a substance used in an organism's metabolism which must be taken in from its environment. Nutrients are the substances that enrich the body. They build and repair tissues, give heat and energy, and regulate body processes...
during the passage through the stomach by shutting down much protein production. When the surviving bacteria exit the stomach and reach the
small intestineIn vertebrates, the small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where the vast majority of digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large...
, they need to propel themselves through the thick
mucusThe mucous membranes are linings of mostly endodermal origin, covered in epithelium, which are involved in absorption and secretion. They line various body cavities that are exposed to the external environment and internal organs. It is at several places continuous with skin: at the nostrils, the...
that lines the small intestine to get to the intestinal wall where they can thrive.
V. cholerae bacteria start up production of the hollow cylindrical protein
flagellinFlagellin is a protein that arranges itself in a hollow cylinder to form the filament in bacterial flagellum. It has a mass of about 30,000 to 60,000 daltons...
to make flagella, the curly whip-like tails that they rotate to propel themselves through the mucus that lines the small intestine.
Once the cholera bacteria reach the intestinal wall, they do not need the flagella propellers to move themselves any longer. The bacteria stop producing the protein flagellin, thus again conserving energy and nutrients by changing the mix of proteins that they manufacture in response to the changed chemical surroundings. On reaching the intestinal wall,
V. cholerae start producing the toxic proteins that give the infected person a watery diarrhea. This carries the multiplying new generations of
V. cholerae bacteria out into the drinking water of the next host—if proper sanitation measures are not in place.
Microbiologists have studied the
genetic mechanismsGene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as rRNA genes or tRNA genes, the product is a functional RNA...
by which the
V. cholerae bacteria turn off the production of some proteins and turn on the production of other proteins as they respond to the series of chemical environments they encounter, passing through the stomach, through the mucous layer of the small intestine, and on to the intestinal wall. Of particular interest have been the genetic mechanisms by which cholera bacteria turn on the protein production of the toxins that interact with host cell mechanisms to pump
chlorideThe chloride ion is formed when the element chlorine picks up one electron to form an anion Cl
−...
ions into the small intestine, creating an ionic pressure which prevents sodium ions from entering the cell. The chloride and sodium ions create a salt water environment in the small intestines which through osmosis can pull up to six liters of water per day through the intestinal cells creating the massive amounts of diarrhea. The host can become rapidly dehydrated if an appropriate mixture of dilute salt water and sugar is not taken to replace the blood's water and salts lost in the diarrhea.
By inserting separate, successive sections of
V. cholerae DNA into the DNA of other bacteria such as
E. coli that would not naturally produce the protein toxins, researchers have investigated the mechanisms by which
V. cholerae responds to the changing chemical environments of the stomach,
mucousMucous may refer to:* The adjectival form of mucus, a slippery secretion of the lining of various membranes in the body* Mucous membrane, a membrane which secretes mucus...
layers, and intestinal wall. Researchers have discovered that there is a complex cascade of regulatory proteins that control expression of
V. cholerae virulenceVirulence is the degree of pathogenicity of an organism: the relative ability of a pathogen to cause disease. The noun virulence derives from the adjective virulent. In discussing disease, the adjective virulent is used to describe effect severity, and in discussing pathogens, the degree of...
determinants. In responding to the chemical environment at the intestinal wall, the
V. cholerae bacteria produce the TcpP/TcpH proteins, which, together with the ToxR/ToxS proteins, activate the expression of the ToxT regulatory protein. ToxT then directly activates expression of
virulenceVirulence is the degree of pathogenicity of an organism: the relative ability of a pathogen to cause disease. The noun virulence derives from the adjective virulent. In discussing disease, the adjective virulent is used to describe effect severity, and in discussing pathogens, the degree of...
genes that produce the toxins that cause diarrhea in the infected person and that permit the bacteria to colonize the intestine. Current research aims at discovering "the signal that makes the cholera bacteria stop swimming and start to colonize (that is, adhere to the cells of) the small intestine."
.
Origin and spread
Cholera likely has its origins in and is
endemicIn epidemiology, an infection is said to be endemic in a population when that infection is maintained in the population without the need for external inputs. For example, chickenpox is endemic in the UK, but malaria is not...
to the
Indian subcontinentThe Indian subcontinent, also Indian Subcontinent and other terms, is a region of the Asian continent on the Indian tectonic plate south of the Himalayas, forming a peninsula which extends southward into the Indian Ocean...
, with the River Ganges serving as a contamination reservoir. The disease spread by trade routes (land and sea) to
RussiaRussia , officially known as both Russia and the Russian Federation , is a country in northern Eurasia . It is a semi-presidential republic, comprising 83 federal subjects...
, then to
Western EuropeWestern Europe is the collection of countries in the westernmost region of Europe, though this definition is context-dependent and carries cultural and political connotations. One definition describes Western Europe as a cultural entity—the region lying west of Central Europe...
, and from Europe to
North AmericaNorth America is the northern continent of the Americas, situated in the Earth's northern hemisphere and in the western hemisphere. It is bordered on the north by the Arctic Ocean, on the east by the North Atlantic Ocean, on the southeast by the Caribbean Sea, and on the west by the North Pacific...
. Cholera is now no longer considered a pressing health threat in Europe and North America due to filtering and
chlorinationChlorination is the process of adding the element chlorine to water as a method of water purification to make it fit for human consumption as drinking water...
of water supplies, but still heavily affects populations in developing countries.
- 1816-1826 - First cholera pandemic
The first cholera pandemic, also known as the first Asiatic cholera pandemic or Asiatic cholera, lasted from 1817 to 1824. While cholera had spread across India many times previously, this outbreak went further; it reached as far as China and the Caspian Sea before receding...
: Previously restricted, the pandemicSee also: 2009 flu pandemic A pandemic is an epidemic of infectious disease that is spreading through human populations across a large region; for instance a continent, or even worldwide. A widespread endemic disease that is stable in terms of how many people are getting sick from it is not a...
began in BengalBengal , is a historical and geographical region in the northeast region of the Indian Subcontinent...
, and then spread across IndiaIndia, officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the south, the Arabian Sea on the west, and the Bay of Bengal...
by 1820. 10,000 British troops and countless Indians died during this pandemic. The cholera outbreak extended as far as ChinaChina is a cultural region, an ancient civilization, and, depending on perspective, a national or multinational entity extending over a large area in East Asia....
, IndonesiaThe Republic of Indonesia is a country in Southeast Asia and Oceania. Indonesia comprises 17,508 islands. With an estimated population of around 237 million people, it is the world's fourth most populous country, with the world's largest population of Muslims.Indonesia is a republic, with an...
(where more than 100,000 people succumbed on the island of JavaJava is an island of Indonesia and the site of its capital city, Jakarta. Once the centre of powerful Hindu-Buddhist kingdoms, Islamic sultanates, and the core of the colonial Dutch East Indies, Java now plays a dominant role in the economic and political life of Indonesia...
alone) and the Caspian SeaThe Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. It has a surface area of 371,000 square kilometres and a volume of 78,200 cubic kilometres...
before receding. Deaths in IndiaThe Indian subcontinent, also Indian Subcontinent and other terms, is a region of the Asian continent on the Indian tectonic plate south of the Himalayas, forming a peninsula which extends southward into the Indian Ocean...
between 1817 and 1860 are estimated to have exceeded 15 million persons. Another 23 million died between 1865 and 1917. RussianThe Russian Empire was a state that existed from 1721 until the Russian Revolution of 1917. It was the successor to the Tsardom of Russia, and the predecessor of the Soviet Union...
deaths during a similar time period exceeded 2 million.
- 1829-1851 - Second cholera pandemic
The second cholera pandemic also known as the Asiatic Cholera Pandemic was a Cholera pandemic from 1829-1851 reached Europe, London and Paris in 1832....
reached Russia (see Cholera Riots- Cholera Riots in Russia :The Cholera Riots were the riots of the urban population, peasants and soldiers in Russia in 1830-1831 during the cholera outbreak....
), HungaryHungary , in English officially the Republic of Hungary , is a landlocked country in the Carpathian Basin of Central Europe, bordered by Austria, Slovakia, Ukraine, Romania, Serbia, Croatia, and Slovenia. Its capital is Budapest. Hungary is a member of OECD, NATO, EU, V4 and is a Schengen state...
(about 100,000 deaths) and GermanyGermany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...
in 1831, London[]London is the capital of England and the United Kingdom. It has been a major settlement for two millennia, and the history of London goes back to its founding by the Romans, when it was named Londinium. London's core, the ancient City of London, the 'square mile', retains its medieval boundaries...
(more than 55,000 people died in the United KingdomThe United Kingdom of Great Britain and Ireland was the formal name and the state form of the United Kingdom from 1 January 1801 until 12 April 1927...
) and ParisParis is the capital of France and the country's most populous city. It is situated on the river Seine, in northern France, at the heart of the Île-de-France region...
in 1832. In London, the disease claimed 6,536 victims and came to be known as "King Cholera"; in ParisParis is the capital of France and the country's most populous city. It is situated on the river Seine, in northern France, at the heart of the Île-de-France region...
, 20,000 succumbed (out of a population of 650,000) with about 100,000 deaths in all of FranceFrance , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...
. The epidemic reached Quebec, Ontario and New YorkNew York is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous. The state is bordered by New Jersey and Pennsylvania to the south, and Connecticut, Massachusetts and Vermont to the east...
in the same year and the Pacific coast of North America by 1834. The 1831 cholera epidemic killed 150,000 people in EgyptEgypt , officially the Arab Republic of Egypt, is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Western Asia...
. In 1846, cholera struck MeccaMecca , sometimes spelled Makkah is the holiest meeting site of the Islamic religion. The city is modern, cosmopolitan and whilst being closed to non-Muslims is nonetheless ethnically diverse.Islamic tradition attributes the beginning of Mecca to Ishmael's descendants...
, killing over 15,000 people. A two-year outbreak began in England and WalesEngland and Wales is a legal unit within the United Kingdom. It consists of England and Wales, two of the four countries of the United Kingdom. Unlike Scotland and Northern Ireland, England and Wales follow the legal system known as English law, and the two form the constitutional successor to the...
in 1848 and claimed 52,000 lives.
- 1849 - Second major outbreak in Paris. In London, it was the worst outbreak in the city's history, claiming 14,137 lives, over twice as many as the 1832 outbreak. Cholera hit Ireland
Ireland is the third-largest island in Europe and the twentieth-largest island in the world. It lies to the north-west of continental Europe and is surrounded by hundreds of islands and islets. To the east of Ireland, separated by the Irish Sea, is the island of Great Britain...
in 1849 and killed many of the Irish Famine survivors already weakened by starvation and fever. In 1849 cholera claimed 5,308 lives in the port city of LiverpoolLiverpool is a city and metropolitan borough of Merseyside, England, along the eastern side of the Mersey Estuary. It was founded as a borough in 1207 and was granted city status in 1880...
, EnglandEngland is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west and the North Sea to the east, with the English Channel to the south separating it from continental...
, and 1,834 in HullKingston upon Hull , almost invariably referred to as Hull, is a city and unitary authority area in the ceremonial county of the East Riding of Yorkshire, England. It is located 25 miles from the North Sea on the River Hull at its junction with the Humber estuary...
, England. An outbreak in North America took the life of former U.S. PresidentThe President of the United States is the head of state and head of government of the United States and is the highest political official in the United States by influence and recognition...
James K. PolkJames Knox Polk was the 11th President of the United States .Polk was born in Mecklenburg County, North Carolina, but mostly lived in and represented the state of Tennessee...
. Cholera, believed spread from ship(s) from England, spread throughout the Mississippi river systemThe Mississippi River is the second longest river in the United States, with a length of from its source in Lake Itasca in Minnesota to its mouth in the Gulf of Mexico....
killing over 4,500 in St. Louis and over 3,000 in New Orleans as well as thousands in New YorkNew York is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous. The state is bordered by New Jersey and Pennsylvania to the south, and Connecticut, Massachusetts and Vermont to the east...
. MexicoThe United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
was similarly attacked. In 1849 cholera was spread along the CaliforniaThe California Trail was a major overland emigrant trail of about across the western half of the North American continent from Missouri River towns to what is now the state of California. It was used primarily from 1841 to 1869...
, MormonThe Mormon Trail or Mormon Pioneer Trail is the route that members of The Church of Jesus Christ of Latter-day Saints traveled from 1846 to 1868...
and Oregon TrailThe Oregon Trail was one of the main overland migration routes on the North American continent, leading from locations on the Missouri River to the Oregon Territory. The eastern half of the trail was also used by travelers on the California Trail, Bozeman Trail, and Mormon Trail which used much of...
s as 6,000 to 12,000 are believed to have died on their way to the California Gold RushThe California Gold Rush began on January 24, 1848, when gold was discovered by James Wilson Marshall at Sutter's Mill, in Coloma, California. News of the discovery soon spread, resulting in some 300,000 men, women, and children coming to California from the rest of the United States and...
, UtahUtah is a western state of the United States. It was the 45th state admitted to the Union, on January 4, 1896. Approximately 80 percent of Utah's 2,736,424 people live along the Wasatch Front, centering around Salt Lake City. In contrast, vast expanses of the state are nearly uninhabited, making...
and OregonOregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
in the cholera years of 1849-1855. It is believed that over 150,000 Americans died during the two pandemics between 1832 and 1849.
- 1852-1860 - Third cholera pandemic
The third cholera pandemic was an outbreak of cholera that occurred from 1852-1860, and mainly affected Russia, with over a million deaths. In 1853-1854, London's epidemic claimed over 10,000 lives with 23,000 deaths for all of Britain.-External links:*...
mainly affected Russia, with over a million deaths. In 1852, cholera spread east to IndonesiaThe Republic of Indonesia is a country in Southeast Asia and Oceania. Indonesia comprises 17,508 islands. With an estimated population of around 237 million people, it is the world's fourth most populous country, with the world's largest population of Muslims.Indonesia is a republic, with an...
and later invaded ChinaChina is a cultural region, an ancient civilization, and, depending on perspective, a national or multinational entity extending over a large area in East Asia....
and Japan in 1854. The PhilippinesThe Philippines officially known as the Republic of the Philippines, is a country in Southeast Asia with Manila as its capital city. It comprises 7,107 islands in the western Pacific Ocean....
were infected in 1858 and KoreaKorea is a civilization and formerly unified nation currently divided into two states. Located on the Korean Peninsula, it borders China to the northwest, Russia to the northeast, and is separated from Japan to the east by the Korea Strait....
in 1859. In 1859, an outbreak in Bengal once again led to the transmission of the disease to IranIran , officially the Islamic Republic of Iran is a country in Western Asia. The name Iran has been in use natively since the Sassanid period and came into international use from 1935, before which the country was known internationally as Persia...
, IraqIraq , officially the Republic of Iraq , also known as Mesopotamia, is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert.Iraq shares borders with Jordan to the west, Syria...
, Arabia and Russia.
- 1854 - Outbreak of cholera in Chicago
Chicago is the largest city in the U.S. state of Illinois, and with more than 2.8 million people, the 3rd largest city in the United States...
took the lives of 5.5% of the population (about 3,500 people). In 1853-4, London's epidemic claimed 10,738 lives. The SohoSoho is an area in the centre of the West End of London, England, in the City of Westminster. It is an entertainment district which for much of the later part of the 20th century had a reputation for its sex shops as well as its night life and film industry...
outbreak in London ended after removal of the handle of the Broad Street pump by a committee instigated to action by John SnowJohn Snow was a British physician and a leader in the adoption of anaesthesia and medical hygiene. He is considered to be one of the fathers of epidemiology, because of his work in tracing the source of a cholera outbreak in Soho, England, in 1854.-Early life and education:Snow was born 15 March...
. This proved that contaminated water (although it didn't identify the contaminant) was the main agent spreading cholera. It would take almost 50 years for this message to be believed and acted upon. Building and maintaining a safe water system was and is not cheap—but is absolutely essential.
- 1863-1875 - Fourth cholera pandemic
The fourth cholera pandemic was the fourth major pandemic of cholera that spread from 1863-1875 began in the Bengal region when Indian Muslim pilgrims visiting Mecca spread the disease through the Middle East.-External links:*...
spread mostly in Europe and AfricaAfrica is the world's second-largest and second most-populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area. With a billion people in 61 territories, it accounts for about 14.8% of the...
. At least 30,000 of the 90,000 MeccaMecca , sometimes spelled Makkah is the holiest meeting site of the Islamic religion. The city is modern, cosmopolitan and whilst being closed to non-Muslims is nonetheless ethnically diverse.Islamic tradition attributes the beginning of Mecca to Ishmael's descendants...
pilgrims fell victim to the disease. Cholera claimed 90,000 lives in Russia in 1866. The epidemic of cholera that spread with the Austro-Prussian WarThe Austro-Prussian War was a war fought in 1866 between the Austrian Empire and its German allies on one side and the Kingdom of Prussia with its German allies and Italy on the other, that...
(1866) is estimated to have claimed 165,000 lives in the Austrian EmpireThe Austrian Empire was a modern era successor empire founded on a remnant of the Holy Roman Empire centered on what is today's Austria that officially lasted from 1804 to 1867...
. Hungary and BelgiumThe Kingdom of Belgium is a country in northwest Europe. It is a founding member of the European Union and hosts its headquarters, as well as those of other major international organizations, including NATO...
both lost 30,000 people and in the NetherlandsThe Netherlands is a country in Northwestern Europe, constituting the major portion of the Kingdom of the Netherlands. It is a parliamentary democratic constitutional monarchy. The Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east...
20,000 perished. In 1867, ItalyItaly , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia. Italy shares its northern, Alpine boundary with France, Switzerland, Austria and Slovenia...
lost 113,000 lives.
- 1866 - Outbreak in North America. It killed some 50,000 Americans. In London, a localized epidemic in the East End claimed 5,596 lives just as London was completing its major sewage and water treatment systems—the East End was not quite complete. William Farr
William Farr was a nineteenth century British epidemiologist, regarded as one of the founders of medical statistics.-Early life:He was born in Kenley, Shropshire, England to poor parents...
, using the work of John SnowJohn Snow was a British physician and a leader in the adoption of anaesthesia and medical hygiene. He is considered to be one of the fathers of epidemiology, because of his work in tracing the source of a cholera outbreak in Soho, England, in 1854.-Early life and education:Snow was born 15 March...
et al. as to contaminated drinking water being the likely source of the disease, was able to relatively quickly identify the East London Water Company as the source of the contaminated water. Quick action prevented further deaths. Also a minor outbreak at YstalyferaYstalyfera is a former industrial village situated on the River Tawe in the unitary authority of Neath Port Talbot, Wales. The estimated population for Ystalyfera and neighbouring Ystradgynlais is 10,247, with an estimate of 4,000 for Ystalyfera itself...
in South Wales. Caused by the local water works using contaminated canal water, it was mainly its workers and their families who suffered, 119 died. In the same year more than 21,000 people died in Amsterdam, The Netherlands.
- 1881-1896 - Fifth cholera pandemic
The fifth cholera pandemic was the fifth major outbreak of cholera that occurred in the years 1881-1896 starting in India. The 1892 outbreak in Hamburg, Germany was the only major European outbreak; about 8,600 people died in Hamburg. Although generally held responsible for the virulence of the...
; According to Dr A. J. Wall, the 1883-1887 epidemic cost 250,000 lives in Europe and at least 50,000 in Americas. Cholera claimed 267,890 lives in RussiaThe Russian Empire was a state that existed from 1721 until the Russian Revolution of 1917. It was the successor to the Tsardom of Russia, and the predecessor of the Soviet Union...
(1892); 120,000 in SpainSpain , officially the Kingdom of Spain , is a country located in southwestern Europe on the Iberian Peninsula.
[The Spanish constitution does not establish any official denomination of the country, even though España , Estado español and Nación española are used interchangeably...]
; 90,000 in Japanis an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
and 60,000 in PersiaIran , officially the Islamic Republic of Iran is a country in Western Asia. The name Iran has been in use natively since the Sassanid period and came into international use from 1935, before which the country was known internationally as Persia...
. In EgyptEgypt , officially the Arab Republic of Egypt, is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Western Asia...
cholera claimed more that 58,000 lives. The 1892 outbreak in HamburgHamburg is the second-largest city in Germany and the sixth-largest city in the European Union...
killed 8,600 people. Although generally held responsible for the virulence of the epidemic, the city government went largely unchanged. This was the last serious European cholera outbreak.
- 1899-1923 - Sixth cholera pandemic
The sixth cholera pandemic was a major outbreak of cholera from the years 1899 to 1923. It killed more than 800,000 in India then erupted in the Middle East, northern Africa, Russia and Eastern Europe....
had little effect in Europe because of advances in public health, but major Russian cities (more than 500,000 people dying of cholera during the first quarter of the 20th century) and the Ottoman EmpireThe Ottoman Empire or Ottoman State , also known by its contemporaries as the Turkish Empire or Turkey , was an empire that lasted from 1299 to November 1, 1922 The Ottoman Empire or Ottoman State (Ottoman Turkish: دَوْلَتِ عَلِیَّهِ عُثْمَانِیَّه Dawlet-il ʿAliyyat-il ʿOs̠māniyye, Modern Turkish:...
were particularly hard hit by cholera deaths. The 1902-1904 cholera epidemic claimed 200,000 lives in the PhilippinesThe Philippines officially known as the Republic of the Philippines, is a country in Southeast Asia with Manila as its capital city. It comprises 7,107 islands in the western Pacific Ocean....
. 27 epidemics were recorded during pilgrimages to MeccaMecca , sometimes spelled Makkah is the holiest meeting site of the Islamic religion. The city is modern, cosmopolitan and whilst being closed to non-Muslims is nonetheless ethnically diverse.Islamic tradition attributes the beginning of Mecca to Ishmael's descendants...
from the 19th century to 1930, and more than 20,000 pilgrims died of cholera during the 1907–08 hajjThe Hajj is a pilgrimage to Mecca . It is currently the largest annual pilgrimage in the world, and is the fifth pillar of Islam, an obligation that must be carried out at least once in their lifetime by every able-bodied Muslim who can afford to do so...
. The sixth pandemic killed more than 800,000 in IndiaIndia, officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the south, the Arabian Sea on the west, and the Bay of Bengal...
. The last outbreak in the United States was in 1910-1911 when the steamship Moltke brought infected people to New York City. Vigilant health authorities isolated the infected on Swinburne IslandSwinburne Island is the smaller of two artificial islands located in the Lower New York Bay east of South Beach, Staten Island.-History:The island was created in 1860. Along with Hoffman Island, it was used to quarantine immigrants to the United States in the early 20th century who were found to be...
. Eleven people died, including a health care worker on Swinburne IslandSwinburne Island is the smaller of two artificial islands located in the Lower New York Bay east of South Beach, Staten Island.-History:The island was created in 1860. Along with Hoffman Island, it was used to quarantine immigrants to the United States in the early 20th century who were found to be...
.
- 1961-1970s - Seventh cholera pandemic
The seventh cholera pandemic was the seventh major outbreak of cholera and occurred from the years 1961 to the 1970s and has continued to the present. The outbreak began in Indonesia, called El Tor after the strain, and reached Bangladesh in 1963, India in 1964, and the USSR in 1966. From North...
began in IndonesiaThe Republic of Indonesia is a country in Southeast Asia and Oceania. Indonesia comprises 17,508 islands. With an estimated population of around 237 million people, it is the world's fourth most populous country, with the world's largest population of Muslims.Indonesia is a republic, with an...
, called El TorEl Tor is the name given to a particular strain of the bacterium Vibrio cholerae, the causative agent of cholera. Also known as V. cholera biotype eltor, it has been the dominant strain in the seventh global pandemic. It is distinguished from the classic strain at a genetic level, although both are...
after the strain, and reached Bangladesh, officially the People's Republic of Bangladesh is a country in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...
in 1963, India in 1964, and the USSR in 1966. From North AfricaNorth Africa or Northern Africa is the northernmost region of the African continent, linked by the Sahara to Sub-Saharan Africa.Geopolitically, the UN definition of Northern Africa includes the following seven countries or territories; Algeria, Egypt, Libya, Morocco, Sudan, Tunisia,Mauritania, and...
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 BakuBaku , sometimes known as Baqy, Baky, Baki or Bakou, is the capital, the largest city, and the largest port of Azerbaijan and all the Caucasus. Located on the southern shore of the Absheron Peninsula, the city consists of two principal parts: the downtown and the old Inner City...
in 1972, but information about it was suppressed in the USSR.
- January 1991 to September 1994 - Outbreak in South America
South America is the southern continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere...
, apparently initiated when a ship discharged ballast water. Beginning in PeruPeru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean.Peruvian territory was home to the Norte Chico...
there were 1.04 million identified cases and almost 10,000 deaths. The causative agent was an O1, El Tor strain, with small differences from 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 NaduTamil Nadu is one of the 28 states of India. Its capital and largest city is Chennai . Tamil Nadu lies in the southernmost part of the Indian Peninsula and is bordered by Puducherry , Kerala, Karnataka and Andhra Pradesh...
, 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 of the emergence of wide-spectrum resistance to drugs such as trimethoprimTrimethoprim is a bacteriostatic antibiotic mainly used in the prophylaxis and treatment of urinary tract infections. It belongs to the class of chemotherapeutic agents known as dihydrofolate reductase inhibitors...
, sulfamethoxazoleSulfamethoxazole is a sulfonamide bacteriostatic antibiotic. It is most often used as part of a synergistic combination with trimethoprim in a 5:1 ratio in co-trimoxazole , also known under trade names such as Bactrim, Septrin, or Septra...
and streptomycinStreptomycin is an antibiotic drug, the first of a class of drugs called aminoglycosides to be discovered, and was the first antibiotic remedy for tuberculosis. It is derived from the actinobacterium Streptomyces griseus. Streptomycin is a bactericidal antibiotic. Streptomycin cannot be given...
.
Recent and ongoing outbreaks
- In 2000, some 140,000 cholera cases were officially notified to WHO. Africa
Africa is the world's second-largest and second most-populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area. With a billion people in 61 territories, it accounts for about 14.8% of the...
accounted for 87% of these cases.
- July - December 2007 - A lack of clean drinking water in Iraq
Iraq , officially the Republic of Iraq , also known as Mesopotamia, is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert.Iraq shares borders with Jordan to the west, Syria...
has led to an outbreakA lack of clean drinking water in Iraq in 2007 has led to an outbreak of cholera.According to Dr. Ryadh Abdul Ameer, the director of the Basra health ministry, basic water sterilization has become impossible in some places due to restrictions on the availability of chlorine for water...
of cholera. As of 2 December 2007, the UN has reported 22 deaths and 4,569 laboratory-confirmed cases.
- August 2007 - The cholera epidemic started in Orissa
Orissa , is a state of India, located on the east coast of India, by the Bay of Bengal. It is the modern name of ancient republican nation of Kalinga, which was invaded by the Indian Emperor Ashoka in 261 BC, that led to a turning point in the Emperor's life when deeply saddened by the bloodshed...
, IndiaIndia, officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the south, the Arabian Sea on the west, and the Bay of Bengal...
. The outbreak has affected Rayagada, Koraput and Kalahandi districts where more than 2,000 people have been admitted to hospitals.
- August - October 2008 - As of 29 October 2008, a total of 644 laboratory-confirmed cholera cases, including eight deaths, had been verified in Iraq
Iraq , officially the Republic of Iraq , also known as Mesopotamia, is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert.Iraq shares borders with Jordan to the west, Syria...
.
- March - April 2008 - 2,490 people from 20 provinces throughout Vietnam
Vietnam , officially the Socialist Republic of Vietnam , is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea to the east...
have been hospitalized with acute diarrhea. Of those hospitalized, 377 patients tested positive for cholera.
- November 2008 - Doctors Without Borders reported an outbreak in a refugee camp in the Democratic Republic of the Congo
The Democratic Republic of the Congo is a country located in Central Africa, with a small length of Atlantic coastline. It is the third largest country in Africa...
's eastern provincial capital of GomaGoma is a city in the eastern Democratic Republic of the Congo, on the northern shore of Lake Kivu, next to the Rwandan city of Gisenyi. The lake and the two cities are in the western branch of the Great Rift Valley, and Goma lies only 13 to 18 km due south of the crater of the active...
. Some 45 cases were reportedly treated between November 7 through 9th.
{| cellpadding="3" border="1" class="wikitable"
! bgcolor="#DDDDDD" colspan="6" | 2008 Zimbabwean cholera outbreak WHOThe World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health...
daily updates
29 March 2009 to 16 April 2009 |
| Date | New cases | Deaths | Date | New cases | Deaths |
|---|
| 29 March 2009 |
242 |
15 |
8 April 2009 |
130 |
3 |
| 30 March 2009 |
92 |
2 |
9 April 2009 |
137 |
0 |
| 31 March 2009 |
76 |
3 |
10 April 2009 |
81 |
2 |
| 1 April 2009 |
259 |
7 |
11 April 2009 |
84 |
6 |
| 2 April 2009 |
166 |
10 |
12 April 2009 |
73 |
1 |
| 3 April 2009 |
44 |
0 |
13 April 2009 |
78 |
1 |
| 4 April 2009 |
132 |
1 |
14 April 2009 |
363 |
30 |
| 5 April 2009 |
19 |
6 |
15 April 2009 |
115 |
9 |
| 6 April 2009 |
536 |
7 |
16 April 2009 |
314 |
10 |
| 7 April 2009 |
182 |
13 |
|
|
|
| Total |
1748 |
64 (CFR = 3.66%) |
Total |
1375 |
62 (CFR=4.51%) |
- August 2008 - April 2009: In the 2008 Zimbabwean cholera outbreak, which is still continuing, an estimated 96,591 people in the country
Zimbabwe , is a landlocked country located in the southern part of the continent of Africa, between the Zambezi and Limpopo rivers...
have been infected with cholera and, by 16 April 2009, 4,201 deaths had been reported. According to the World Health OrganizationThe World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health...
, during the week of 22–28 March 2009, the "Crude Case Fatality Ratio (CFR)" had dropped from 4.2% to 3.7%. The daily updates for the period 29 March 2009 to 7 April 2009, list 1748 cases and 64 fatalities, giving a weekly CFR of 3.66% (see table above); however, those for the period 8 April to 16 April list 1375 new cases and 62 deaths (and a resulting CFR of 4.5%). The CFR had remained above 4.7% for most of January and early February 2009.
- January 2009 - The Mpumalanga province of South Africa
The Republic of South Africa is a country located at the southern tip of Africa, with a coastline on the Atlantic and Indian Oceans. To the north lie Namibia, Botswana and Zimbabwe, to the east are Mozambique and Swaziland, while Lesotho is an independent country surrounded by South Africa.Modern...
has confirmed over 381 new cases of Cholera, bringing the total number of cases treated since November 2008 to 2276. 19 people have died in the province since the outbreak.
Pandemic genetic diversity
Amplified fragment length polymorphism (AFLP) fingerprinting of the
pandemicSee also: 2009 flu pandemic A pandemic is an epidemic of infectious disease that is spreading through human populations across a large region; for instance a continent, or even worldwide. A widespread endemic disease that is stable in terms of how many people are getting sick from it is not a...
isolates of
Vibrio cholerae has revealed variation in the genetic structure. Two clusters have been identified: Cluster I and Cluster II. For the most part Cluster I consists of strains from the 1960s and 1970s, while Cluster II largely contains strains from the 1980s and 1990s, based on the change in the clone structure. This grouping of strains is best seen in the strains from the African Continent.
Famous victims
The pathos in the last movement of
Tchaikovsky'sPyotr Ilyich Tchaikovsky
[The subject's names are also transliterated Piotr, Petr, or Peter; Ilitsch, Ilich, Il'ich or Illyich; and Tschaikowski, Tschaikowsky, Chajkovskij and Chaikovsky...]
(c. 1840-1893) last symphony made people think that Tchaikovsky had a premonition of death. One observer noted that a week after the premiere of his
Sixth SymphonyThe Symphony No. 6 in B minor, Pathétique, Op. 74 is Pyotr Ilyich Tchaikovsky's final symphony, written between February and the end of August 1893. The composer led the first performance in St. Petersburg on October 28 of that year, nine days before his death. The second performance, under Eduard...
, "Tchaikovsky was dead--6 November 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 tap 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 believed to have died of cholera include:
Research
The Russian-born bacteriologist
Waldemar HaffkineWaldemar Mordecai Wolff Haffkine was a bacteriologist who worked in India. He was the first microbiologist who developed and used vaccines against cholera and bubonic plague. He tested the vaccines on himself...
developed the first cholera vaccine around 1900.
The bacterium had been originally isolated thirty years earlier (1855) by Italian anatomist
Filippo PaciniFilippo Pacini was an Italian anatomist, posthumously famous for isolating the cholera bacillus Vibrio cholerae in 1854, well before Robert Koch's more widely accepted discoveries thirty years later....
, but its exact nature and his results were not widely known around the world.
One of the major contributions to fighting cholera was made by the physician and pioneer medical scientist
John SnowJohn Snow was a British physician and a leader in the adoption of anaesthesia and medical hygiene. He is considered to be one of the fathers of epidemiology, because of his work in tracing the source of a cholera outbreak in Soho, England, in 1854.-Early life and education:Snow was born 15 March...
(1813-1858), who found a link between cholera and contaminated drinking water in 1854. Dr Snow proposed a microbial origin for epidemic cholera in 1849 and in his major state of the art review of 1855 he proposed a substantially complete and correct model for the aetiology of the disease. In two pioneering epidemiological field-studies he was able to demonstrate that human sewage contamination was the most probable disease vector in two major epidemics in London in 1854. His model was not immediately accepted but was seen to be the more plausible as medical microbiology developed over the next thirty years or so. Massive investment in clean water supply and well separated sewage treatment infractures was made between the mid-1850s and the 1900s which eliminated the threat of cholera epidemics from the major developed cities in the world.
Robert KochHeinrich Hermann Robert Koch was a German physician. He became famous for isolating Bacillus anthracis , the Tuberculosis bacillus and the Vibrio cholera and for his development of Koch's postulates....
, 30 years later, identified
V. cholerae with a microscope as the bacillus causing the disease in 1885.
Cholera has been a laboratory for the study of evolution of virulence. The province of Bengal in
British IndiaThe British Raj was the British colonial rule in the Indian subcontinent between 1858 and 1947; it can also refer to the period of dominion, and even the region under the rule...
was partitioned into
West BengalWest Bengal is a state in eastern India. With Bangladesh, which lies on its eastern border, the state forms the ethno-linguistic region of Bengal. To its northeast lie the states of Assam and Sikkim and the country Bhutan, and to its southwest, the state of Orissa...
and
East PakistanEast Pakistan was a former province of Pakistan which existed between 1947 and 1971. East Pakistan was created from Bengal Province based on a plebiscite in what was then British India in 1947. Eastern Bengal chose to join the Dominion of Pakistan and became a province of Pakistan by the name East...
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, officially the People's Republic of Bangladesh is a country in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south...
). As a consequence, the strains of the pathogen that 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 victims.
More recently, in 2002, Alam et al. studied stool samples from patients at the
International Centre for Diarrhoeal DiseaseThe International Centre for Diarrhoeal Disease Research, Bangladesh is an international health research organisation. It is located in Dhaka, Bangladesh and was established in 1978. The Centre is credited with discovering oral rehydration therapy for the treatment of diarrhoea and cholera...
(ICDDR) in Dhaka, Bangladesh. From the various experiments they conducted, the researchers found a correlation between the passage of
V. cholerae through the human digestive system and an increased infectivity state. Furthermore, the researchers found that the bacterium creates a hyper-infected state where
geneA gene is the basic unit of heredity in a living organism. All living things depend on genes. Genes hold the information to build and maintain their cells and pass genetic traits to offspring...
s that control biosynthesis of
amino acidAmino acids are molecules containing an amine group, a carboxylic acid group and one of the twenty R-groups. These molecules are particularly important in biochemistry, where this term refers to alpha-amino acids with the general formula H
2NCHRCOOH, where R is an organic substituent...
s, iron uptake systems, and formation of periplasmic nitrate reductase complexes were induced just before defecation. These induced characteristics allow the cholera vibrios to survive in the rice water stools, an environment of limited oxygen and iron, of patients with a cholera infection.
False historical report
A persistent myth states that
90,000 people died in ChicagoThe Chicago 1885 cholera epidemic myth is a persistent urban legend, stating that 90,000 people in Chicago died of typhoid fever and cholera in 1885. Although the story is widely reported, these deaths did not occur....
of cholera and
typhoid feverTyphoid fever, also known as enteric fever, Salmonella typhi or commonly just typhoid, is an illness. Common worldwide, it is transmitted by the ingestion of food or water contaminated with feces from an infected person. The bacteria then perforate through the intestinal wall and are phagocytosed...
in 1885, but this story has no factual basis. In 1885, there was a torrential rainstorm that flushed the
Chicago RiverThe Chicago River is a river that runs 156 miles and flows through Chicago, including the downtown. Though not especially long, the river is notable for the 19th century civil engineering feats that directed its flow south, away from Lake Michigan, into which it previously emptied, and towards...
and its attendant pollutants into Lake Michigan far enough that the city's water supply was contaminated. However, because cholera was not present in the city, there were no cholera-related deaths, though the incident caused the city to become more serious about its sewage treatment.
Cholera morbus
The term
cholera morbus was used in the 19th and early 20th centuries to describe both non-epidemic cholera and other gastrointestinal diseases (sometimes epidemic) that resembled cholera. The term is not in current use, but is found in many older references. The other diseases are now known collectively as
gastroenteritisGastroenteritis is inflammation of the gastrointestinal tract, involving both the stomach and the small intestine and resulting in acute diarrhea...
.
Other historical information
In the past, people traveling in ships would hang a yellow
quarantineQuarantine is voluntary or compulsory isolation, typically to contain the spread of something considered dangerous, often but not always disease...
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, typically 30 to 40 days.. In modern
international maritime signal flagsThe system of international maritime signal flags is a way of representing individual letters of the alphabet in signals to or from ships. It is a component of the International Code of Signals...
the quarantine flag is yellow and black.
See also
- The Ghost Map: The Story of London's Most Terrifying Epidemic - and How it Changed Science, Cities and the Modern World
The Ghost Map: The Story of London's Most Terrifying Epidemic - and How it Changed Science, Cities and the Modern World is a book by Steven Berlin Johnson in which he describes the most intense outbreak of cholera in Victorian London - and what it means to us today, from the way we understand...
- which tells the story of how John SnowJohn Snow was a British physician and a leader in the adoption of anaesthesia and medical hygiene. He is considered to be one of the fathers of epidemiology, because of his work in tracing the source of a cholera outbreak in Soho, England, in 1854.-Early life and education:Snow was born 15 March...
found the cause of a cholera epidemic, which was the start of modern epidemiology.
- The Painted Veil (2006 film)
The Painted Veil is a 2006 American/Chinese drama film directed by John Curran. The screenplay by Ron Nyswaner is based on the 1925 novel of the same title by W. Somerset Maugham...
, starring Naomi Watts and Edward Norton, in which cholera is a prominent subject, based on the novel of the same name by W. Somerset MaughamWilliam Somerset Maugham , CH was an English playwright, novelist and short story writer...
.
- The Horseman on the Roof
The Horseman on the Roof is a 1995 French film directed by Jean-Paul Rappeneau. Starring Juliette Binoche and Olivier Martinez, it is based on the 1951 French novel, Le hussard sur le toit by Jean Giono.-Plot:...
(1995 film), starring Juliette Binoche and Olivier Martinez, in which the 1832 cholera outbreak in southern France is a major influence to the story line.
- The Dress Lodger by Sheri Holman
Sheri Holman is an American novelist. After graduating from The College of William & Mary in 1988 with a degree in Theatre, Holman moved to New York and worked in various positions in the publishing industry, eventually becoming the assistant to a literary agent...
- A historical novel set in Sunderland, England during the cholera epidemic of 1831The Cholera epidemic of 1831 was an epidemic of the disease cholera in the United Kingdom, an episode in the larger Second cholera pandemic that affected most of the Eastern Hemisphere...
.
- In the novel Death in Venice
The novella Death in Venice was written by the German author Thomas Mann, and was first published in 1912 as Der Tod in Venedig. It was first published in English in 1925 as Death in Venice and Other Stories, translated by Kenneth Burke. W. H...
by Thomas MannThomas Mann was a German novelist, short story writer, social critic, philanthropist, essayist, and 1929 Nobel Prize laureate, known for his series of highly symbolic and ironic epic novels and novellas, noted for their insight into the psychology of the artist and the intellectual...
(also a 1971 film by Lucino Visconti starring Dirk Bogard), the main character dies of cholera in VeniceVenice is a city in northern Italy, the capital of the region Veneto, a population of 271,367 . Together with Padua, the city is included in the Padua-Venice Metropolitan Area . The city historically was an independent nation...
; the epidemic is a recurring sub-plot of the story.
- Love in the Time of Cholera
Love in the Time of Cholera is a novel by Nobel Prize winning Colombian author Gabriel García Márquez that was first published in Spanish in 1985, with an English translation released in 1988 by Alfred A. Knopf...
, a novel by Nobel Prize winning Colombian author Gabriel García Márquez, and its English-language film adaptationLove in the Time of Cholera is a 2007 motion picture directed by Mike Newell. Based on the novel of the same name by Gabriel García Márquez, it tells the story of a love triangle between Fermina Daza and her two suitors, Florentino Ariza and Doctor Juvenal Urbino which spans 50 years, from 1880...
.
- Cholera, the social disease, (2007 documentary short film) Documentary short film about cholera outbreak in Angola, 2007.
External links
- Cholera - World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health...
- What is Cholera? - Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention is a United States federal agency under the Department of Health and Human Services based in Atlanta, Georgia. It works to protect public health and safety by providing information to enhance health decisions, and it promotes health through...
- Cholera information for travelers - Centers for Disease Control and Prevention
- Steven Shapin, "Sick City: Maps and mortality in the time of cholera", The New Yorker
The New Yorker is an American magazine of reportage, commentary, criticism, essays, fiction, satire, cartoons, and poetry published by Condé Nast Publications...
May 2006. A review of Steven Johnson, “The Ghost Map: The story of London’s most terrifying epidemic — and how it changed science, cities, and the modern world”
- Cholera Epidemic in NYC in 1832 New York Times 15 April 2008
- Cholera vaccine: the cheapest