Malaria. Coloured scanning electron micrograph (SEM) of red blood cells and Plasmodium falciparum protozoa. These protozoa (yellow) cause malaria. The disease is spread by bites from infected tropical mosquitoes (Anopheles sp.). At this stage the plasmodia are known as merozoites. These are small parasites which enter the red blood cells, multiply, and cause the cell to burst, releasing more plasmodia into the bloodstream. This release of plasmodia into the blood causes a high fever. The lack of red blood cells leads to anaemia, and mis-shapen infected blood cells can block blood vessels, leading to kidney failure, coma, and death. Magnification: x4000 at 6x6cm size.