Cholera epidemics are bred in areas where poor sanitary conditions exist, particularly crowded urban settings. This often fatal intestinal disease is spread by the comma-shaped Vibrio cholerae bacteria. A highly contagious disease, cholera epidemics have been reported since antiquity. Despite advances in medicine, cholera outbreaks still occur today. In January 1998, 13,440 cholera cases were reported in the Democratic Republic of the Congo, Africa, with 778 deaths. Such outbreaks are not uncommon and serve as grim reminders that technology has not yet conquered this dangerous disease.

Cholera victims initially suffer from diarrhea, vomiting, and cramps. Eventually, dehydration and cyanosis set in as the face takes on a bluish tint and the extremities become dark and cold. The disease is spread primarily by unwashed hands, unwashed fruits, and sewage-contaminated water supplies. Following an incubation period of 24 to 72 hours and the onset of diarrhea, victims are treated with large quantities of fluids, as well as the administration of glucose. Although less effective during severe outbreaks when health facilities are overcrowded with victims, rehydration therapy has, nevertheless, saved countless lives.

The cholera organism was isolated by Robert Koch, a German physician who led a government-supported scientific expedition into Egypt where an epidemic was underway in 1883. The epidemic ended before Koch had completed his research; he took his group to India, the sites of another cholera epidemic, to continue his investigation. In 1884, Koch cited the bacterium Vibrio cholerae as the causative agent of cholera.

Travelers are advised not to eat raw fish or unwashed foods when they visit countries where cholera outbreaks continue. Failure to treat the disease often results in death. The current cholera vaccine is not recommended to Americans traveling abroad, since the brief coverage it offers does not offset its side effects. In fact, travelers have been warned to avoid vaccination in unsanitary conditions in developing countries. Researchers continue to work on an oral vaccine that could prove to be effective.