Alone or in combination, economic collapse, war, and natural disasters, among other societal disruptions, have caused (and could again cause) the breakdown of public health measures and the emergence or reemergence of a number of deadly diseases.
Cholera, a sometimes rapidly fatal diarrheal disease caused by the bacterium Vibrio cholerae, reached epidemic levels in South America in January 1991 for the first time in almost a century. Inadequate sanitation played a role in its reappearance, which occurred initially in several coastal cities in Peru; then the disease spread through much of the continent. A scattering of epidemic-related cases were reported later in the year in Central America and the United States. As of December 1991, there had been 366,056 reported cases of the disease and 3,894 deaths in these three regions (Pan American Health Organization, 1991).
It is believed that V. cholerae was first introduced into the harbor at Lima, Peru, through the dumping of bilge water by a ship arriving from the Far East. Once in the water, the bacteria rapidly contaminated the fish and shellfish, which were then consumed (often in the form of ceviche, a dish made with raw seafood that is popular in that part of the world). Following the initial seafood-related cases in humans, the organisms are thought to have been spread by fecal contamination of the water supply.
Epidemiologic investigations in Peru have implicated such contaminated municipal water supplies as the principal means by which the disease is now being transmitted. Based on a study by the U.S. Environmental Protection Agency (EPA) that showed a possible link between chlorination and cancer, Peruvian officials apparently ceased treating much of the country's drinking water in the early 1980s (C. Anderson, 1991). A paucity of hygienic food preparation practices also appears to have played a role.
The epidemic is traveling northward at a rapid rate; several cases have already been reported in the United States, originating from contaminated foodstuffs. U.S. public health authorities are maintaining a close watch on foods imported from South and Central America (the majority of fresh fruits and vegetables imported into the United States during the winter come from Mexico). In February 1992, at least 31 of 356 passengers and crew aboard a flight from Buenos Aires, Argentina, to Los Angeles, California (with a brief stopover in Lima) were diagnosed with cholera (18 in California, 9 in Nevada, 3 in Japan, and 1 in Argentina—1 person died). At least 54 other passengers reported having diarrhea of unknown etiology. This illustration demonstrates the ease with which this disease can be transported worldwide (Centers for Disease Control, 1992c).