The disease can be horrific, as the National Geographic Channel explains. Cholera ravaged Britain with four epidemics in the mid-19th century, one killing 30,000 people in London alone. At the time, health officials thought it was an airborne illness; only later did they figured out that tainted drinking water was the culprit.
People get cholera by eating food or drinking water that's been contaminated by feces from someone infected with the bacterium. Poor hygiene and unsanitary living conditions -- like those in Haiti after the devastating January quake -- can spread the disease. But the Centers for Disease Control and Prevention in March predicted cholera shouldn't have been a problem.
