Leishmania donovani

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1. Leishmania donovani

2. Phylum: Sarcomastigophora Class: Zoomastigophora Genus: Leishmania

3. Geographical distribution Endemic: India, China, Africa, Southern Europe, South America & Russia Habitat Parasite of R.E. system In the vertebrate host, is always intracellular: amastigote form

4. Morphology: Amastigote stage ( Aflagellar stage): man Promastigote form ( Flagellar stage) : gut of sandfly & in artificial culture

5. Amastigote stage Shape: Round or oval body 2-4 µm Cell membrane: delicate Nucleus: ‹1 mm in diameter; oval or round Kinetoplast comprises of DNA- containing body & a mitochondrial structure: lies at rt. a ngle to nucleus Axoneme : filament extending from kinetoplast : represents the root of flagellum

6. Promastigote stage Slender spindle shaped body: 15-20µm X 1-2 µm Nucleus: central Flagellum projects from the front

7. Reservoir of infection: dog; man Transmission: sandfly of genera Phlebotomus & Lutzomyia

8. Life cycle

9. Man Amastigote form: multiplies by binary fission; host cell enlarged : becomes packed by parasites, eventually ruptures Parasite again taken up by fresh cells & the cycle is repeated Some free amastigotes phagocytosed by neutrophilic granulocytes & monocytes (macrophages) Sandfly draws these free amastigote form a.w.a those within monocytes during its blood meal Life cycle

10. Sandfly Amastigote forms develop into promastigote form: multiply by binary fission in the mid gut of sandfly The flagellates then spreads to anterior part of alimentary canal (pharynx & buccal cavity) Heavy pharyngeal infection observed b/w 6-9 th day after blood meal (anterior station infection) Bite of sandfly : infection

11. Incubation period: 3-6 months Clinical features Pyrexia: double rise in 24 hrs Splenic enlargement Liver enlarged Epistaxis Skin dry,rough & pigmented Jaundice Anemia

12. Diagnosis Direct evidences Microscopy Splenic pulp tissue Bone marrow Blood Lymph node: aspirate or biopsy

13. Culture 1-2 ml of blood taken aseptically from a vein: diluted with 10ml citrated saline solution Cells allowed to settle in a cool incubator (22˚C) Cellular deposits inoculated in the water of condensation of N.N.N medium ( Novy , MacNeal , Nicolle ) : incubated at 22˚C for 1-4 weeks

14. Serological test DAT RK-39 test

15. Indirect evidences Blood count: neutropenia , relative increase of lymphocytes & monocytes Serological tests: Aldehyde test: for rise of gamma globulin Antimony tests Complement fixation tests with W.K.K. antigen

16. Leishmanin test Adler’s test

17. Treatment Antimony compounds Pentamidine isethionate

18. Prophylaxis Attack on parasite Attack on vector Personal prophylaxis

19. Post kala azar dermal leishmaniasis Depigmented macules Erythematous patches Yellowish pink nodules