Diagnosis:
- Clinical Features:
- Fever (often cyclic, e.g., tertian or quartan patterns)
- Chills, sweats, myalgia, headache
- Splenomegaly (common in falciparum and vivax malaria)
- Anemia, jaundice (more common in falciparum)
- Hemoglobinuria (blackwater fever, specific to falciparum)
- Laboratory Confirmation:
- Microscopy: Gold standard; identifies species and quantifies parasitemia.
- Thick and thin blood smears (Giemsa stain).
- Rapid diagnostic tests (RDTs) for P. falciparum (HRP-2 antigen) or pan-species (pLDH).
- PCR: Useful for low parasitemia or species confirmation.
- Microscopy: Gold standard; identifies species and quantifies parasitemia.
- Differential Diagnosis: Viral infections, typhoid, dengue, leptospirosis.
- Treatment (Non-Immune Individuals, e.g., Travelers):
- Uncomplicated Falciparum Malaria:
- First-line: Artemisinin-based combination therapy (ACT) (e.g., artemether-lumefantrine, artesunate-amodiaquine).
- Rationale: High efficacy, reduces resistance risk.
- Alternatives: Atovaquone-proguanil, quinine + doxycycline (if ACT unavailable).
- First-line: Artemisinin-based combination therapy (ACT) (e.g., artemether-lumefantrine, artesunate-amodiaquine).
- Severe Falciparum Malaria (Parasitemia >5%, organ dysfunction):
- Parenteral Therapy:
- IV artesunate (preferred) or IV quinine.
- Rationale: Artesunate reduces mortality vs. quinine.
- Oral Transition: Once stable, switch to ACT.
- Parenteral Therapy:
- Vivax/Ovule Malaria:
- Chloroquine: First-line (if sensitive; resistance in some regions).
- Radical Cure: Primaquine (14 days) to eradicate liver hypnozoites.
- Rationale: Prevents relapse.
- Special Populations:
- Pregnancy: Quinine + clindamycin (1st trimester) or ACT (2nd/3rd).
- Pediatrics: Dose-adjusted ACT (e.g., artemether-lumefantrine).
- Key Considerations:
- Resistance: P. falciparum resistance to chloroquine, mefloquine, and sulfadoxine-pyrimethamine in some regions.
- Prevention: Chemoprophylaxis (e.g., atovaquone-proguanil, mefloquine) for travelers.
- Monitoring: Follow-up smears to confirm parasite clearance.