Death from malaria illness is primarily due to infection with which species?

• A. P. falciparum
• B. P. vivax
• C. P. malariae
• D. P. ovale

Answer: (A)

Death from malaria is primarily due to infection with P. falciparum because this species can produce very high levels of parasitemia and has the ability to make infected red blood cells stick to the lining of small blood vessels (cytoadherence) and form clumps (rosetting). This leads to obstruction of microcirculation, tissue hypoxia, and damage to multiple organs, especially the brain, causing cerebral malaria and severe, often fatal, complications. Other malaria species, like P. vivax, P. malariae, and P. ovale, can cause illness too, but they generally do not reach the same extreme parasite loads or cause the same degree of vascular sequestration, so fatalities are much less common.