Malaria. Coloured scanning electron micrograph (SEM) of red blood cells infected with Plasmodium falciparum protozoa. Of the 4 Plasmodium species that cause malaria, P. falciparum is the one most likely to cause death if left untreated. The pro- tozoa appear here as yellowish areas just under the surface of the blood cells. After invading a red blood cell, the Plasmodia go through a number of stages, reproducing asexually until the blood cell ruptures and releases them. The disease is spread by bites from infected tropical mosquitoes (Anoph- eles sp.). Malaria kills red blood cells, leading to anaemia, blocked blood vessels, kidney failure, coma & death. Magnification: x3200 at 6x6cm size.