Overview
Definition
A life-threatening mosquito-borne blood disease caused by a Plasmodium parasite.
Epidemiology
Endemic in tropical and subtropical regions (Sub-Saharan Africa, South Asia). A leading cause of death in children under 5 globally.
Etiology & Risk Factors
- Plasmodium falciparum (most severe), P. vivax, P. ovale, P. malariae, and P. knowlesi.
- Transmitted by the bite of an infected female Anopheles mosquito.
- Parasites multiply in the liver, then infect and destroy red blood cells.
Clinical Symptoms
- Paroxysms of cyclically occurring chills, followed by high fever, and then profuse sweating (cycles occur every 48-72 hours depending on the species)
- Headache, fatigue, myalgias
- Jaundice (due to hemolysis) and dark urine
- Splenomegaly
Clinical Approach
Diagnosis
- Thick and Thin Peripheral Blood Smears (Gold Standard): Thick smear detects the presence of parasites; Thin smear identifies the specific Plasmodium species and parasitemia level
- Rapid Diagnostic Tests (RDTs): Detect specific malaria antigens in blood (very useful in endemic areas)
Management
- Uncomplicated (P. falciparum): Artemisinin-based Combination Therapy (ACT), e.g., Artemether-lumefantrine
- Severe (P. falciparum): IV Artesunate (preferred) or IV Quinine
- P. vivax / P. ovale: Require Primaquine or Tafenoquine to eradicate the dormant liver hypnozoites and prevent relapse (Must test for G6PD deficiency first!)
Complications
- Cerebral Malaria (coma, seizures - high mortality)
- Severe anemia
- Acute Kidney Injury ('Blackwater fever')
- Pulmonary edema