Metabolic component: The third line of defense is slow, best measured by the base excess, and mostly depends on the renal system which can add or remove bicarbonate ions (HCO−3) to or from the ECF. Bicarbonate ions are derived from metabolic carbon dioxide which is enzymatically converted to carbonic acid in the renal tubular cells. There, carbonic acid spontaneously dissociates into hydrogen ions and bicarbonate ions. When the pH in the ECF falls, hydrogen ions are excreted into urine, while bicarbonate ions are secreted into blood plasma, causing the plasma pH to rise. The converse happens if the pH in the ECF tends to rise: bicarbonate ions are then excreted into the urine and hydrogen ions into the blood plasma.The second and third lines of defense operate by making changes to the buffers, each of which consists of two components: a weak acid and its conjugate base. It is the ratio concentration of the weak acid to its conjugate base that determines the pH of the solution. Thus, by manipulating firstly the concentration of the weak acid, and secondly that of its conjugate base, the pH of the extracellular fluid (ECF) can be adjusted very accurately to the correct value. The bicarbonate buffer, consisting of a mixture of carbonic acid (H2CO3) and a bicarbonate (HCO−3) salt in solution, is the most abundant buffer in the extracellular fluid, and it is also the buffer whose acid-to-base ratio can be changed very easily and rapidly.
Contrary to the actual facts of how violently cholera kills, Mann has his protagonist die peacefully on a beach in a deck chair. Luchino Viscontis 1971 film version also hid from the audience the actual course of the disease. Manns novella was also made into an opera by Benjamin Britten in 1973, his last one, and into a ballet by John Neumeier for his Hamburg Ballet company, in December 2003. *
In Gabriel Garcia Márquezs 1985 novel Love in the Time of Cholera, cholera is "a looming background presence rather than a central figure requiring vile description." The novel was adapted in 2007 for the film of the same name directed by Mike Newell. Country examples
Zambia
In Zambia, widespread cholera outbreaks have occurred since 1977, most commonly in the capital city of Lusaka. In 2017, an outbreak of cholera was declared in Zambia after laboratory confirmation of Vibrio cholerae O1, biotype El Tor, serotype Ogawa, from stool samples from two patients with acute watery diarrhea. There was a rapid increase in the number of cases from several hundred cases in early December 2017 to approximately 2,000 by early January 2018.