Cholera was and remains one of the most dangerous and widespread of all bacterial diseases. It is capable of running rampant in the water supply of almost any community where sanitation is anything less than rigorous. This deadly disease is responsible for deaths in many circumstances where close living quarters, poor sanitation and limited water supplies pertain, in particular in refugee camps and areas of extreme poverty.
Vibrio cholerae is a rod-shaped bacteria with a flagella, found naturally in wetlands, water sources and are particularly associated with estuary conditions and stagnant waters. There are many strains of Vibrio cholerae; some are largely harmless. However, those that are virulent can be deadly, especially to the young, the ill and those with a weakened physical system. The deadly strains all have the ability to produce a toxin called "cholera toxin," which causes severe diarrhea, among other symptoms.
Vibrio cholerae are native to coastal and estuary environments with shallow waters and thriving planktonic eco-systems. In this situation, they naturally attach to small planktonic crustaceans called "copepods." These copepods feed on algae in the waters and as they flourish so do the Vibrio cholerae bacteria. Populations rise and fall with the rise and fall of available algae.
Organic pollutants, in particular human and animal fecal wastes, provide nutrients to encourage algae blooms. The combination of an organically rich environment, coupled with the perfect temperatures and salinity levels cause natural cholera epidemics to be associated with seasonal shifts: a densely populated coastline coupled with the natural temperatures and saline levels of spring and fall ensure the best possible chances of an outbreak.
Vibrio cholerae bacteria are not contagious from person to person under normal circumstances. They pass into the human digestive system through ingestion, usually by way of water, though food products taken from contaminated waters and insufficiently cooked can serve as a vector, as can hand-to-mouth contact after harvesting and processing such foods. Once the bacteria are released in diarrhea and enter the water source, however, they can spread rapidly and create a fully contaminated water supply.
Duration of Contagion
In a coastal estuary environment, Vibrio cholerae bacteria are normal and, when no massive population increase is in effect, are unlikely to be present in high enough levels as to present a strong threat to the average human. Populations die down during high summer and winter, and it has been discovered that Vibrio cholerae bacteria can enter a dormant stage in which they survive in the silt at the bottom of the estuary, appearing completely absent from copepod populations and from the waters of the estuary until conditions are again ripe for reproductive success. This ability caused the bacteria and its associated outbreaks to appear a great mystery for many long years after the symbiotic connection with copepods had been discovered.
In the Human Body
Vibrio cholerae are not naturally part of the human body, and the problems they cause are the result of toxins produced by the bacteria, not a result of the bacteria establishing a desired ecological niche in the human gut. They exist as transients and to the degree that they multiply at all in a fecal environment, they are still not a human-integrated bacteria. On being ingested, the strains of Vibrio cholerae produce a toxin which triggers the cells of the small intestine to flood the gut with liquid, producing a watery stool. In extreme cases, the victim can excrete gallons of liquid waste in hours, and die as quickly.
The primary treatment of cholera is through the replacement of liquids and ions to the system, preventing collapse from dehydration. Antibiotics are of little use, though they may shorten recovery time. Because the Vibrio cholerae bacteria are not natural to the human gut and do not form an associative relationship to the human system, the primary requirement is to survive their temporary presence and the effects of their toxin. Liquids can be administered by IV or, with glucose added, can be given orally, or both methods can be used.
As cholera can kill incredibly rapidly there should be no delay if a case is suspected.
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