[Malaria: an update].

More than 100 years have passed since the discovery of its aetiological agent, but malaria is still the first cause of morbidity and mortality in the world. After the initial illusory successes of the fight against the infection, malarial infection is currently in a phase of expansion due to the sum of several contributory factors: the rise of anophelism related to the failure of eradication campaigns in endemic areas, due to environmental, structural and economic causes; the spread of stocks of chloroquine-resistant Plasmodium falciparum in such areas; the increase in travel for work and tourism, and the flows of populations due to wars, political issues, or just survival. In this paper we inspected all the aspects of the infection, from historical aspects - in which there was sometimes a mingling of history and legend - to those more properly defined as scientific. We seek to point out less well-known details, both about the vector and the clinical-epidemiological aspects concerning the populations in endemic areas, semi-immune subjects and foreigners. We also underline the importance both of prophylaxis and treatment of infection in travellers in high-risk areas, in the light of pharmacological resistance developed by the parasite and of the new usable molecules.