Malaria is one of the most serious and complex health problems facing humanity in the 20th century. Approximately 300 million of the world's people are infected by the disease and between 1 and 1.5 million people die from it every year. Previously extremely widespread, the disease is now mainly confined to the poorer tropical areas of Africa, Asia and Latin America. The problems of controlling malaria in these countries are aggravated by inadequate health structures and poor socioeconomic conditions. The situation has become even more complex over the last few years with the increase in resistance to the drugs normally used to combat the parasite that causes the disease.
Malaria is caused by protozoan parasites of the genus Plasmodium.
Four species of Plasmodium can produce the disease in its various forms - Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale and Plasmodium malaria. Parasites are transmitted from one person to another by the female anopheline mosquito. The males do not transmit the disease as they feed only on plant juices. There are some 380 species of anopheline mosquito, but only 60 species are able to transmit the parasite. Sensitivity to insecticides is also highly variable.