## Identification of Kinetoplast-Bearing Parasites **Key Point:** The kinetoplast is a specialised mitochondrial structure unique to trypanosomatid protozoa, visible as a dark-staining dot on Giemsa-stained peripheral blood smears. ### Morphology of Trypanosoma brucei - **Size:** 15–30 μm long, 1–3 μm wide - **Shape:** Spindle-shaped with pointed posterior end - **Flagellum:** Single anterior flagellum arising from kinetoplast - **Kinetoplast:** Located at the posterior end; appears as a dark granule on light microscopy - **Undulating membrane:** Extends along the body length ### Comparison with Other Blood Parasites | Parasite | Kinetoplast | Morphology on Blood Smear | Staining | | --- | --- | --- | --- | | Trypanosoma brucei | **Present** (visible dot) | Spindle, flagellated | Giemsa: dark kinetoplast | | Plasmodium vivax | Absent | Ring/trophozoite forms | Giemsa: cytoplasm + nucleus | | Wuchereria bancrofti | Absent | Microfilariae (sheathed) | Giemsa: elongated, no kinetoplast | | Entamoeba histolytica | Absent | Trophozoites (in stool, not blood) | Iodine: nucleus with karyosome | **High-Yield:** The kinetoplast is pathognomonic for Trypanosoma and Leishmania species; no other blood parasite possesses this structure. **Clinical Pearl:** In African trypanosomiasis (sleeping sickness), the kinetoplast is visible in wet preparations and Giemsa smears during the parasitaemic phase, making it a rapid diagnostic feature.
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.