Hemoflagellates: Blood and Tissue Flagellates

1. BLOOD & TISSUE FLAGELLATES/HAEMOFLAGELLATES

2. Morphologic forms • There are 4 morphologic forms seen in hemoflagellates: • Amastigote • Promastigote • Epimastigote • Trypomastigote -they can exist in two or more of the 4 morphologic forms  depending on the species.

3. Kingdom: Protisata • Phylum: Sarcomastigophora • Class: Zoomastigophora • Order: Kimetoplastida • Family: Trypanosomatidae • Genus:Leishmania • Species:donovani , tropica, mexicana, braziliensis

4. Leismania sp. • Can cause: • Cutaneous leishmaniasis: a localized infection of the capillaries of the skin. • Mucocutaneous leishmaniasis: cause lesions of the skin and mucous membranes, specifically of the oral and nasal mucosa. • Visceral/sistemic leismaniasis: more generalized symptoms leading to enlargement of the internal organs, especially the liver, lymph nodes and spleen.

5. Geographical distribution

6. Leishmania sp. • Divided into 4 groups: 1) Leishmania tropica complex – Old World Cutaneous Leismaniasis. 2) Leishmania mexicana complex – New World Cutaneous Leishmaniasis. 3) Leishmania braziliensis complex – Mucocutaneous Laishmaniasis. 4) Leishmania donovani complex – Visceral leishmaniasis.

7. Stage of life • Only have 2 stages of life: • Amastigote • Promastigote

8. Amastigote • Size: 5 by 3µm • Shape: oval to round • Nucleus: One, eccentric. • Kinetoplast: Present, Consisting of dot-like blepharoplast, with small axoneme and prabasal body. • Flagellum: absent

9. Promastigote • Size: 9-15µm • Shape: long and slender. • Nucleus: one, central. • Kinetoplast: Anterior end of the organism, no undulating membrane. • Flagellum: Single, anterior free flagellum.

10. Leishmania tropica complex – Old World Cutaneous Leismaniasis. • L. tropica - mediterranean region, middle East, Armenia, Caspian region, Afghanistan, India and Kenya (particularly in urban areas)

11. Morphology • Cause a chronic disease: cutaneous leishmanisis. • Also known as Oriental sore, Delhi boil and dry or urban cutaneous leishmaniasis. • Characterized by: production of dry, raised, ulcerated lesions at bite sites. • Vectored by: tiny sandflies of the genera Phlebotomus.

12. L. tropica

13. Vector: Phlebotomus sandfly

14. Sandfly vs mosquito mosquito sandfly

16. Life cycle

19. Laboratory Diagnosis • Montenegro (leishmanin) skin test -delayed hypersensitivity reaction provoked by a suspension of killed leishmanial promastigotes administered intradermally. -local inflammatory reaction appears at the site of injection within 48-72 hours. • Microscopy examination • Isoenzyme studies • Molecular diagnostic technique- PCR • Serologic test – ex: indirect fluorescent antibody assay.

20. Leishmania braziliensis complex – Mucocutaneous Leishmaniasis • L. braziliensis – Mexico to Argentina

21. Morphology • Cause infections throughout the Americas from Mexico to Argentina. • The distinguishing feature of these infectious is the development of ulcers on or about the oral and nasal mucosa • L. braziliensis causes espundia.

22. espundia

23. Diagnosis • By demonstrating amastigotes of Leishmania in Giemsa stained smears or biopsy material from the edge of an active ulcer. • Cultivation. • Serologic test. • Montenegro skin test.

24. Leishmania donovani complex – Visceral leishmaniasis • L. donovani – India, Pakistan, Thailand, parts of Africa and the Peoples Republic of China. • L. infantum – Mediterranean area, Europe, Africa, the Near East, and parts of the former Soviet Union. • L. chagasi – Central and South America.

25. Morphology • Visceral leishmanisis also known as Kala Azar or dum-dum fever. • The most severe of the Leishmaniasis. • Generally a disease of juveniles and young adults. • Natural reservoir: rodents and dog. • In India, man appears to be the only mamalian reservoir. • L. donovani complex –parasitize the reticuloendothelial cells, viscerotropic, infected macrophages remaining fixed or disseminate throughout the body.

26. In the Mediterranean are, Europe, Africa, Soviet union – Phlebotomus sandfly remains the vector. Natural reservoir: domesticated dogs, canines and porcupines. • In the New World (Central and South America) – Lutzomiya sandfly remains the vector. Natural reservoir: Foxes, domestic dogs and cats.

27. Life cycle • Same with L. mexicana complex. • The infected mononuclear phagocytes do not remain confined to the skin or mucous membranes. • Parasitized macrophages are carried by the bloodstream to lymphoid tissue throughout the body especially to the spleen, liver and bone marrow. • Amastigotes multiply in great numbers in this tissues. • Vectors: Phlebotomus sandfly and Lutzomiya sandfly .

29. Diagnosis • Tissues Biopsy • Direct examination of stained smears. • Cultivation. • Serologic test. • Direct agglutination test (DAT). • Complement fixation test (CF). • Indirect fluorescence technique. • Molecular diagnostic technique. • Montenegro skin test (not reactive in people with active disease).

30. Promastigotes (left) and amastigotes (right) of Leishmania parasites. Parasites have been fixed in Giemsa stained.