Ins and Outs of Vibrio cholerae

T he gram-negative, motile, curvedrod bacterium Vibrio cholerae can cause cholera—an acute, explosive diarrheal disease. Epidemic cholera was described in the 1500s, but reports of cholera-like symptoms date back much earlier, to the times of Hippocrates and the Buddha. In 1849 John Snow, a London physician, determined that cholera is transmitted by water, and in 1883 Robert Koch successfully isolated the cholera vibrio. Facilitated by the expansion of global trade routes, cholera spread worldwide in 1817 and remains a global health challenge. Cholera patients typically lose large volumes of fluid. If left untreated, even previously healthy adult patients may become severely dehydrated and can die. Although rehydration therapy makes cholera survivable, it does not cure the diarrhea or prevent infections. Cholera remains a social and economic burden, especially in the developing world. In 2006 the World Health Organization reported a total of 236,896 cholera cases with 6,311 deaths worldwide. These figures likely greatly underestimate the toll of cholera. Many cases go unreported during seasonal outbreaks, and a substantial percentage of people die without diagnosis.