Cholera: molecular basis for emergence and pathogenesis

Cholera clearly knows well the role of the grim reaper. It is one of the first diseases most people think of when calamity strikes and civilization breaks down. We have seen this happen several times in the last decade, with the most dramatic example being the cholera deaths of 80 000 people in the Rwandan refugee camps of Goma, Zaire, in 1994. While cholera as a disease is probably not as old as others like tuberculosis or smallpox, it clearly has been around for at least a thousand years. Although there are many diarrheal diseases, the intensity of cholera and the explosiveness of cholera epidemics clearly is unmistakable and must have impressed ancient observers. For example, there are descriptions that could only be cholera in ancient Greek and Chinese literature. As noted by Pollitzer, the translation by Schmidt of a Sanskrit work whose origin is believed to be Tibet around 802 AD clearly suggests cholera: “When the strength of virtues and merits decreases on earth, there appears amongst the people, first among those living on the shores of big rivers, various ailments which gives no time for treatment, but prove fatal immediately after they appear.… The various vessels secrete water so that the body becomes empty.… Its first signs are dizziness, a numb feeling in the head, and then the most violent purging and vomiting (Trans.)” [1]. Pollitzer also noted that in 1543 the explorer Gaspar Correa described a cholera victim in an outbreak in India in which the fatality rate exceeded the survivors' ability to bury the dead: “So grievous was the throe, and so bad a sort that the very worst poison seemed to take effect, as proved by vomiting, with drought of water accompanying it, as if the stomach were parched up, and cramps that fixed …