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.
• 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).
  • 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.
  • 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.