Hans Andersag (1902–1955)
Malaria is one of the major causes of death worldwide and the most critical health problem in more than ninety countries, home to 40 percent of the world’s population. There are four different strains of Plasmodium, the malaria-causing protozoan parasite, and these are transmitted by a bite of the female Anopheles mosquito. The two most common forms of malaria are caused by P. vivax and P. falciparum, which are responsible for the characteristic high fever, chills, and profuse sweating. Unlike P. vivax, which is common outside of Africa and relatively mild, P. falciparum is responsible for some 90 percent of all human infections (200–300 million cases annually)—98 percent of which are in Africa—and 90 percent of all malaria deaths.
When supplies of quinine were cut off by the Japanese during World War II, an all-out effort was initiated in the United States to discover quinine substitutes to treat malaria. Of the 14,000 compounds screened, chloroquine proved to be the most effective. In retrospect, it was determined that chloroquine was first synthesized at the Elberfeld laboratories of IG Farben in Germany in 1934 by Hans Andersag and named Resochin but not used because of its perceived toxicity.
More powerful and less toxic than quinine, chloroquine (Aralen) has been the drug of choice for the prevention and treatment of malarial infections since the mid-1940s. Its many advantages include its effectiveness, quick action, long-lasting effects, few adverse reactions, safety during pregnancy, and very low cost. In the late 1950s, early signs of resistance began to appear. By the 1980s, chloroquine-resistant strains of P. falciparum became widespread throughout much of the world, with the exception of the Caribbean islands, parts of Central America, North Africa, and the Middle East, where chloroquine remains highly effective. Hints are emerging that it may be regaining its effectiveness in Africa.
SEE ALSO Quinine (1820), Artemisinin (1972).
Charles Alphonse Laveran (1845–1922) made this drawing of malaria parasites. A French physician who discovered in 1880 that protozoa caused malaria, he was the first person to identify protozoa as diseasing-causing agents, and for which he was awarded the 1907 Nobel Prize in Physiology or Medicine.