Water began to stagnate in discarded barrels, in the broken pots and pans. It was cupped in bamboo scaffoldings, in the beginnings of gardens, and in the thin marsh of the valley basin. It was largely responsible for keeping Africa the Dark Continent, closed to Europeans. Until the twentieth century, the cause of malaria remained a mystery, with most people believing that it was caused by poisonous gases released at night from tainted soil. Now we know malaria to be an insect-borne parasitic disease.
Scientists believe that it started in Africa and spread to Europe, Asia, and the Americas.
Malaria was and still is endemic in forty percent of the world. But even before DDT, some countries had managed to radically reduce their malaria problems. The eradication efforts were not so successful in the rest of the world. The map above shows just how unsuccessful. With the increase of ecotourism and tourism to exotic places, we will encounter an increasing number of people returning with the disease.