What is malaria?

Quick overview

Malaria is an infectious disease transmitted by mosquitoes. It is caused by minute parasitic protozoa of the genus Plasmodium, which infect human and insect hosts alternately.

The typical symptom of malaria is a violent fever lasting 6—8 hours, recurring every two or three days. The different species of Plasmodium cause two types of intermittent fever (Fig. 2). A tertian fever has one day free of fever between paroxysms; a quartan fever has two. Anaemia and enlargement of the spleen develop as the disease progresses.

Malaria is the world's worst health problem. At this moment more people are ill with malaria than any other disease, and the numbers affected or at risk are increasing remorselessly.   Control measures are becoming less effective, and the threat of epidemic malaria is increasing in many tropical areas.