Definition: Malaria is a life-threatening mosquito-borne disease caused by Plasmodium parasites, primarily P. falciparum and P. vivax.
- Transmission: Spread via Anopheles mosquitoes; humans serve as the definitive host.
- Pathogenesis:
- P. falciparum: Severe disease, multiorgan dysfunction (e.g., cerebral malaria, ARDS, renal failure).
- P. vivax: Relapsing course due to liver-stage hypnozoites (dormant forms).
- Clinical Features:
- Cyclical fevers, chills, sweats, anemia, splenomegaly.
- P. falciparum: Rapid progression to severe illness (e.g., seizures, coma, hemolysis).
- Diagnosis: Microscopy (Giesma-stained blood smears), rapid diagnostic tests (RDTs), PCR.
- Treatment:
- P. falciparum: Artemisinin-based combination therapy (ACT) (e.g., artemether-lumefantrine).
- P. vivax: Chloroquine + primaquine (to eradicate hypnozoites; may fail due to resistance).
- Prevention: Vector control (ITNs, IRS), chemoprophylaxis (e.g., atovaquone-proguanil), and RTS,S/AS01 vaccine (partial protection).
Rationale: Malaria’s clinical spectrum and treatment vary by species; P. vivax’s relapse potential and P. falciparum’s severity necessitate tailored approaches.