Which Plasmodium species is most strongly associated with severe malaria and cerebral malaria?

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

Answer: (A)

The main idea is that severe, especially cerebral, malaria is driven by the parasite’s ability to clog the brain’s microvasculature. Plasmodium falciparum does this best because infected red blood cells express surface proteins (like PfEMP1) that cause strong cytoadherence to endothelial cells and rosetting with uninfected cells. This leads to sequestration of parasitized cells in deep and cerebral vessels, allowing very high parasite loads to build up without being cleared by the spleen. The result is impaired cerebral perfusion, hypoxia, and metabolic disturbances that manifest as altered consciousness, coma, and seizures—hallmarks of cerebral malaria. Other species—P. vivax, P. malariae, and P. ovale—tend to cause malaria with lower parasite densities and lack the same degree of sequestration, so they are far less commonly associated with severe or cerebral forms.