MI3.10-12 | Malaria & Blood Parasites (incl. Peripheral Smear) — Summary & Reflection

REFLECT

A 35-year-old returning traveller from Assam presents with fever for 6 days. Peripheral smear shows enlarged RBCs with Schüffner's dots and ameboid trophozoites — P. vivax malaria is confirmed.

• What treatment does he receive for the acute attack?
• Before you add primaquine for radical cure (to eliminate hypnozoites), what test is mandatory and why?
• If this patient is G6PD deficient, how would your management change?
• The patient asks: "I was treated for malaria 18 months ago. Could this be the same infection returning?" — How do you explain relapse vs re-infection?

KEY TAKEAWAYS

Malaria species comparison:
- P. falciparum: malignant, banana gametocytes, multiple rings per RBC, appliqué forms, normal-sized RBCs, only rings on smear (sequestration); causes cerebral malaria, blackwater fever, severe anaemia
- P. vivax/ovale: benign tertian, Schüffner's dots, enlarged RBCs, ameboid trophozoites, hypnozoites → relapse
- P. malariae: quartan (72 hr), band-form trophozoites, normal RBCs; associated with nephrotic syndrome

Smear diagnosis:
- Banana gametocyte = P. falciparum (pathognomonic)
- Schüffner's dots + enlarged RBC = P. vivax or P. ovale
- Thick film for sensitivity; thin film for species identification

Kala-azar:
- Leishmania donovani; vector: Phlebotomus sandfly; endemic in Bihar/Jharkhand/WB
- LD bodies in macrophages (bone marrow/splenic smear); rK39 rapid test for field use
- Treatment: liposomal amphotericin B (India)

Filariasis:
- Wuchereria bancrofti; vector: Culex quinquefasciatus; nocturnal blood sample
- Microfilariae: sheathed, no nuclei in tail tip (vs. Brugia malayi: nuclei in tail tip)
- ICT card test for antigen detection; MDA with DEC + albendazole for prevention