Leishmaniasis Leishmania donovani (complex) (VL) Leishmania tropica (CL) Leishmania major (CL) Leishmania aethiopica (CL) Leishmania mexicana (Complex) (CL) Leishmania brazilliensis (complex) (MCL) Leishmania peruriana

The Parasite Phylum Order Family Genus Sarcomastigophora Kinetoplastida Trypanosomatidae Leishmania

Morphology Promasitogte Amastigote Digenetic Life Cycle Insect Motile Midgut Amastigote Mammalian stage Non-motile Intracellular

Morphology Promastigote Amastigote Flagella Kinetoplast Golgi Nucleus Cytoskeleton

Promastigote

Amastigotes (. ) of Leishmania donovani in the cells of a spleen Amastigotes (*) of Leishmania donovani in the cells of a spleen.  The individual amastigotes measure approximately 1 µm in diameter. 

Amastigote

Amastigotes of Leishmania in a macrophage from a lymph node of a dog. 

Leishmania (Leishman-Donovan or LD bodies) Leishmania (Leishman-Donovan or LD bodies). Lying in macrophage cells from liver. Giemsa. ×12000. Enlarged by 9.6.

A macrophage filled with Leishmania amastigotes.

Life cycle The organism is transmitted by the bite of several species of blood-feeding sand flies (Phlebotomus) which carries the promastigote in the anterior gut and pharynx. It gains access to mononuclear phagocytes where it transform into amastogotes and divides until the infected cell ruptures. The released organisms infect other cells. The sandfly acquires the organisms during the blood meal, the amastigotes transform into flagellate promastigotes and multiply in the gut until the anterior gut and pharynx are packed. Dogs and rodents are common reservoirs.

Mammalian Hosts Rodents Gerbils Hyraxes Bats Porcupines Opossums Sloths Primates Dogs Foxes Anteaters . . . . .

Vectors Phlebotomine Sandflies 6 genera world wide distribution Phlebotomus & Lutzomia 500 species Females Haematophagus Males sap feeders

Clinical Disease Visceral Cutaneous Fatal (90% untreated) Liver Spleen Bone marrow Cutaneous Generally Self- healing Skin Mucous membranes SPECTRUM OF DISEASE

Promastigote Amasitgote Initial Infection Similar in all species Inoculation of promastigotes Inflammation & chemotaxis Receptor mediated phagocytosis Promastigote Amasitgote Transformation

Macrophage lysis & parasite release Skin/lymph nodes/spleen/liver/ Parasite Spread Macrophage lysis & parasite release Lymphatic spread Blood spread Target organs Skin/lymph nodes/spleen/liver/ bone marrow

Visceral Leishmaniasis 1903 1920 1931 William Leishman Pentavalent antimony Experimental transmission Leishmania donovani (Complex) L.d. archibaldi - L.d.chagasi - L.d.donovani - Ld.infantum

VL - Clinical Manifestation Variable - Incubation 3-100+ weeks Lowgrade fever Hepato-splenomegaly Bone marrow hyperplasia Anemia, Leucopenia & Cachexia Hypergammaglobulinnemia Epistaxis , Proteinuria, Hematuria

Profile view of a teenage boy suffering from visceral leishmaniasis Profile view of a teenage boy suffering from visceral leishmaniasis. The boy exhibits splenomegaly, distended abdomen and severe muscle wasting. 

A 12-year-old boy suffering from visceral leishmaniasis A 12-year-old boy suffering from visceral leishmaniasis. The boy exhibits splenomegaly and severe muscle wasting.

Jaundiced hands of a visceral leishmaniasis patient. 

Enlarged spleen and liver in an autopsy of an infant dying of visceral leishmaniasis.

Post Kala Azar Dermal Leishmanoid Normally develops <2 years after recovery Recrudescence Restricted to skin Rare but varies geographically

Cutaneous leishmaniasis of the face.

A cutaneous leishmaniasis lesion on the arm.

Sub-clinical or inapparent infection Recovery Death Immune to reinfection Concurrent infection PKDL

Clinical signs & symptoms Hypergammaglobulinemia Diagnosis Clinical signs & symptoms Hypergammaglobulinemia ELISA/Formol gel Bone marrow biopsy Spleen or liver biopsy Culture & Histology

Speciation Similar morphology Isoenzyme profiles - Zymodemes Monoclonal antibodies DNA hybridisation - PCR

New drugs - New delivery Treatment Good nursing Diet Antibiotics Pentavalent antimony Pentamidine New drugs - New delivery

Control Vector control Reservoir control Treatment of active cases Vaccination