Visceral Leishmaniasis PDF

Visceral LEISHMANIASIS Prepared by Dr/ Ragaa Ahmed Assistant lecturer of Medical Parasitology Presented by Dr/ Sara Mohamed Abd Elhady Assistant lecturer of Medical Parasitology  Leishmania Leishmania is an obligatory intracellular bl...

Visceral LEISHMANIASIS Prepared by Dr/ Ragaa Ahmed Assistant lecturer of Medical Parasitology Presented by Dr/ Sara Mohamed Abd Elhady Assistant lecturer of Medical Parasitology  Leishmania Leishmania is an obligatory intracellular blood and tissue flagellate. It is transmitted mainly by different species of sandfly insect. Leishmania acquires 2 morphological forms of the blood flagellates: amastigote intracellulary & promastigote in vector and in culture.  Leishmaniasis General Life Cycle Leishmania parasites inhabit the following: ▪ Reticuloendothelial cells (REC) (macrophages, monocytes, other phagocytic cells). ▪ Lymphoid tissues of different structures (liver, spleen, lymph nodes, bone marrow). ▪ According to its species; the lymphoid cells, and tissues in skin, mucocutaneous or the viscera could be affected.  Classification Visceral Cutaneous Mucocutaneous Leishmania Leishmania Leishmania Old L. donovani L. tropica World complex complex: L. donovani L. tropica L. infantum L. major L. aethiopica New L. chagasi L. mexicana L.braziliensis World complex complex L.braziliensis complex  Morphology 1. Amastigote 2- 4µm Ovoid Vesicular nucleus with large central karyosome Kinetoplast (= origin of flagellum) It is intracellular inside blood monocyte and tissue macrophages. 2. PROMASTIGOTE: 10-20µm Spindle in shape Central vesicular nucleus with central karyosome. Anterior kinetoplast (pro= anterior) Anterior free flagellum It is inside the insect vector and culture Life cycle From life cycle: Final host: human. Infective stage: promastigote. Diagnostic stage: amastigote. Intermediate host ( vector): female sandfly (Phlebotomus in old world and Lutzomyia in new world). Reservoir host: dogs and rodents are the main reservoir hosts.  Visceral leishmaniasis Kala Azar Dum Dum fever Black fever MODE OF TRANSMISSION 1.Bite of female sand fly inoculating metacyclic promastigote. 2. Blood transfusion 3. Organ transplantation 4. Congenital 5. Accidental in lab worker Pathogensis and clinical picture  2wks-2 years Promastigote skin subcut. tissues Macrophage Promastigote Promastigote with multiplying taking by transforms amastigotes macrophage to amastigote Phagocytic blood cells with Monocytosis amastigotes (viscerotropic) Bone marrow depression Hepatomegaly Splenomegaly (leukopenia) stasis of blood destruction of RBCs Lymphadenitis & Lymphadenopathy anaemia K.ElShe wy (Kala Azar) Pathogenesis of visceral leishmaniasis ▪ Incubation period (2 weeks to 2 years) after the sandfly bite. ▪ Papule at site of bite (leishmanioma). ▪ Intermittent fever (double daily rise). ▪ L.N: Lymphadenopathy. ▪ Liver: hepatomegaly, pain and tenderness, with reversal of albumin /globulin ratio. Why?????? ▪ Spleen: splenomegaly & hypersplenism. ▪ Bone marrow: pancytopenia. ▪ Intestine: diarrhea with dysenteric manifestation ▪ Kidney: renal failure d2 immune complex deposition. ▪ Weight loss, cachexia, & emaciation. ▪ Decrease immunity: 2ry bacterial infections & pneumonia. ▪ Skin manifestations : a) Dark pigmented erythematous areas (black fever) b) PKDL(post-kala-azar dermal leishmaniasis) (depigmented skin macules or nodules)(d2 inadequate treatment). Visceral leishmaniasis Visceral leishmaniasis hepatosplenomegaly Cachexia  DIAGNOSIS 1 clinically 2 laboratory: A- Direct: microscopic examination of samples (blood, liver, L.N, spleen) and stain with giemsa stain. Culture on NNN media (promastigote) Animal inoculation (amastigote) PCR B- Indirect: Serological tests (ELISA- IHAT- IFAT…….) Motengro (Leishmanin) skin Test: -ve in active infection, +ve after 2 months of ttt.  Promastigotes in NNN medium TREATMENT Pentavalent antimony compounds: pentostam IM or IV pentamidine Amphotericin B Allopurinol Symptomatic treatment: oRest and good nutrition oAntipyretic for fever oAntibiotics for 2ry bacterial infection oBlood transfusion oSplenectomy in resistant cases ( large Nb of amastigotes)  Prevention Control ✓Treatment of cases. ✓Avoiding sandflies is important but difficult, because they have adapted to urban environments. ✓Using of insecticides. ✓House and space spraying ✓Control of reservoir hosts ✓Vaccination