What is the origin of the word “malaria”?
From Italian “mal” (bad) + “aria” (air) – referring to the historical belief that the disease was caused by miasma or poisonous vapours from swamps.
Why is malaria called “the most important parasitic disease”?
Because it is a scourge of mankind for millennia; in the 20th century alone, an estimated 150–200 million people died from malaria, representing 2–5% of all deaths during that period.
What percentage of the world’s population lives in areas where malaria is transmitted?
0.5
What is the global burden of malaria as of 2024?
According to the WHO World Malaria Report 2025, there were an estimated 282 million cases and 610,000 deaths globally in 2024 – a slight increase from 2023.
How many malaria cases and deaths have been averted since 2000?
Since 2000, malaria control efforts have averted an estimated 2.3 billion cases and 14 million deaths worldwide.
What percentage of global malaria cases and deaths occur in the WHO African Region?
94% of cases and 95% of deaths – the African Region continues to bear the overwhelming burden of malaria.
Which country has the highest malaria burden in the world?
Nigeria – in 2024, Nigeria recorded an estimated 68.5 million cases (24.3% of global cases) and accounted for 30.3% of all malaria deaths globally, approximately 184,800 deaths.
Which five countries account for almost half of all global malaria cases?
Nigeria (24.3%), Democratic Republic of the Congo (12.5%), Uganda (4.7%), Ethiopia (4.4%), and Mozambique (3.6%).
What percentage of malaria deaths in Africa occur in children under five years old?
75% of malaria deaths in the WHO African Region occur in children under five years of age.
What Plasmodium species cause human malaria?
Five species: P. falciparum, P. vivax, P. malariae, P. ovale, and P. knowlesii.
Which Plasmodium species causes the most severe disease and the majority of deaths?
P. falciparum – it accounts for 97% of malaria cases in Africa and is responsible for virtually all severe and complicated malaria.
Which Plasmodium species can cause relapsing malaria due to hypnozoites?
P. vivax and P. ovale – these species form dormant liver stage parasites (hypnozoites) that can cause clinical relapse weeks to months after the initial infection.
Which Plasmodium species is associated with quartan malaria and nephropathy?
P. malariae – it causes fever every 72 hours (quartan periodicity) and is associated with long-term immune complex-mediated nephrotic syndrome (“quartan malaria nephropathy”).
What is P. knowlesii and why is it clinically important?
P. knowlesii is a zoonotic parasite originating from macaque monkeys; it causes daily fever paroxysms (quotidian) and can cause severe disease with high parasite density due to its 24-hour replication cycle.
What are the four main modes of malaria transmission?
1) Bites of infected female Anopheles mosquitoes (primary), 2) Blood transfusion, 3) Organ transplantation, 4) Congenital transmission (mother to foetus).
What are the classic three stages of a malaria paroxysm?
Cold stage (rigors, shivering), hot stage (high fever, headache, vomiting), and wet stage (sweating, defervescence, exhaustion).
What is the typical fever periodicity in P. falciparum malaria?
Irregular or quotidian (daily) – P. falciparum does not have synchronised schizogony, so fever patterns are often irregular, though may become tertian (every 48 hours) in some infections.
What is the typical fever periodicity in P. vivax and P. ovale?
Tertian – fever occurs every 48 hours, corresponding to the completion of the erythrocytic cycle.
What is the typical fever periodicity in P. malariae?
Quartan – fever occurs every 72 hours.
What is the difference between stable and unstable malaria?
Stable malaria: constant high transmission with high population immunity (hyperendemic/holoendemic areas). Unstable malaria: epidemic-prone, low transmission with little population immunity (hypoendemic/mesoendemic areas).
How is malaria endemicity classified using spleen rates in children 0-9 years?
Hypoendemic (<10% spleen rate), Mesoendemic (11-25%), Hyperendemic (26-50%), Holoendemic (>75% – also high spleen rate in adults).
What is PfEMP-1 and its role in pathogenesis?
Plasmodium falciparum Erythrocyte Membrane Protein 1 – a variant surface antigen expressed on infected RBCs that mediates cytoadherence to endothelial receptors (ICAM-1, CD36, VCAM-1), leading to sequestration and severe disease.
What is cytoadherence in malaria pathogenesis?
The adherence of P. falciparum-infected RBCs to vascular endothelium via PfEMP-1 binding to host receptors (ICAM-1, CD36), causing sequestration of parasites in deep microvasculature – a key factor in cerebral malaria and placental malaria.
What is rosetting in malaria pathogenesis?
The adherence of uninfected RBCs to P. falciparum-infected RBCs, forming rosette-like clusters that obstruct microcirculation and contribute to severe malaria pathogenesis.
