falciparum

Plasmodium falciparum is a protozoan parasite and the most virulent species that infects humans, causing the deadliest form of malaria. It accounts for the majority of malaria-related deaths worldwide, particularly in sub-Saharan Africa, and poses ongoing challenges for control and treatment.

The parasite is transmitted by female Anopheles mosquitoes. In humans, sporozoites first infect liver cells, where they develop into merozoites. After release, merozoites invade red blood cells and multiply asexually. P. falciparum can invade red cells of all ages and can produce high parasite densities. Infected red blood cells express PfEMP1 and adhere to the vascular endothelium, a process called cytoadherence, which can lead to microvascular obstruction. Sequestration and rosetting contribute to severe disease, including cerebral malaria and multi-organ dysfunction.

Clinical features range from fever and flu-like symptoms to severe malaria, characterized by anemia, hypoglycemia, lactic acidosis, renal impairment, and cerebral involvement. Diagnosis relies on microscopic examination of blood films or rapid diagnostic tests that detect parasite antigens such as HRP2.

Treatment predominantly uses artemisinin-based combination therapies, after prompt assessment. Chloroquine resistance is widespread, and resistance to artemisinin has emerged in some regions, underscoring the need for effective drugs and supportive care. Prevention focuses on vector control, including insecticide-treated nets and indoor residual spraying, and chemoprophylaxis for travelers.

Genetically, P. falciparum has a genome of about 23.3 megabases organized into 14 chromosomes and contains multigene families such as var, rif, and stevor involved in immune evasion. The species was first described in the late 19th century by Alphonse Laveran.