Leishmaniasis PDF

Leishmaniasis Leishmaniasis Definition: Group of diseases caused by a number of flagellated protozoa species of genus leishmania.  Parasitology: Genus : leishmania Species: L.Tropica, L. donoani. L. major. Morphological forms 1. Amastigote...

Leishmaniasis Leishmaniasis Definition: Group of diseases caused by a number of flagellated protozoa species of genus leishmania.  Parasitology: Genus : leishmania Species: L.Tropica, L. donoani. L. major. Morphological forms 1. Amastigote: - Called LD body. 2. Promastegote: flagellated, only in fly or culture.  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. Life Cycle Promastigote. Epidemiology  Leishmaniasis: the disease Three major groups /complexes:- 1. Leishmania Tropica complex → Cutaneous leishmaniasis 2. Leishmania Brasiliensis → Mucocutaneous leishmaniasis 3. Leishmania donovani → Visceral leishmaniasis Cutaneous leishmaniasis Two forms of CL. Old World CL: L tropica major L tropica minor L ,eathiopica New world CL L maxicana L brasiliensis Cutaneous Leishmaniasis Leishmania tropica Oriental Sore Mediterranean, Middle East Incubation is a month or two. Transmitted by touch & flies to other open wounds. Vaccinated for the Middle East!  Localized self-healing. Papule → Crateriform ulcer →→→ Scar. Microscopically: Dermal MQ filled with amastigotes Intense infiltration of lymphocytes & PC. Necrosis Granuloma Cutaneous leishmaniasis ❖Red papule, itching (Type 4 HSR) + 2ry bacterial infection) ❖ IC parasite. (LD bodies) ❖Satellite or daughter nodules. ❖If ↓ immunity: disseminated (DCL) ❖Heal → scar Cutaneous leishmaniasis  Cutaneous leishmaniasis Diagnosis:- Clinical & epidemiological. Skin smear, scrap, and biopsy→ LD bodies. Culture in (NNN) media. Mucocutaneous Leishmaniasis Caused by L. brasilieinsis complex Not common in Sudan < South America; Transmitted by Lutzumia sand fly. Mucocutaneous Leishmaniasis Pathology & clinical features: Starts as CL →→ Metastatic lesions in mucocutaneous junctions (lips, nose). Heals or ↑↑ in size→ erode MM and cartilage but not bone. 2ry bacterial infection is common  3-Visceral leishmaniasis: Kalazar Transmission In Sudan by sand fly (Phlebotomus Oreintalis) Reservoir in wild animals. Other modes of transmission: Blood transfusion Vertical (congenital) Sexual intercourse Direct contact( rare)  Visceral leishmaniasis: Pathogenesis: Skin bite site→ Promastegote (tail loss) → Amastigote (LD bodies) →lymph nodes→ RES. → replication inside macrophages → cytokines release (TNF, IL1,IL6, Bradykinens) → C/F  Visceral leishmaniasis Liver → Kuffer cell hyperplasia Bone marrow → Infiltration. Spleen →red pulp hyperplasia→ hypersplenism (pancytopenia) LN → reactive lymphadenopathy.  Visceral leishmaniasis Clinical manifestations: Incubation period: 3-6 months. Chronic fever (double peak), sweating, rigor. Wt loss, good appetite. Watery diarrhea. General weakness Clinical manifestations: Massive splenomegally, hepatomegally, ↑LN. Epistaxis. Recurrent infections: pneumonia, dysentery, TB, ect. Skin dyspigmentation Visceral leishmaniasis  Visceral leishmaniasis Clinical diagnosis Lab Diagnosis:- Parasitological Serological Molecular biology Routine investigations  Laboratory diagnosis By finding amastigotes (LD bodies) in: Materials aspirated from spleen,bone marrow or lymph node(visceral) Smears taken from ulcers(cutaneous & mucocutaneous).  Culture: - Novy-MacNeal-Nicolle (NNN) medium. Cultures can produce positive results in 1-3 weeks. Serologic tests: Direct agglutination test (DAT) & rK39 ICT test.(visceral) Indirect fluorescent antibody test (IFAT),ELISA Polymerase chain reaction (PCR)  Others: Complete blood count. Bone marrow infiltration may cause pancytopenia with relative monocytosis & lymphocytosis. Liver function tests (LFTs). Coagulation panel. Hypergammaglobulinemia  The leishmanin skin test (Montenegro test): Produces positive results 3 months after the appearance of lesions. The Montenegro test is performed by injecting killed promastigotes intradermally and examining the skin 48 hours later to see if a delayed-type hypersensitivity response has formed. A positive result : induration of 5 mm or more. Positive result in: The majority of persons in whom infection spontaneously resolves Those who have undergone successful chemotherapy Cutaneous leishmaniasis. Negative results in progressive VL  Visceral leishmaniasis Complications 1. infections. esp dysentery, TB, Pneumonia. 2. Amyloidosis. 3. Pancytopenia: due to BM infiltration & hypersplenism. 5. Cancrum oris 6. Eye pathology: retinal bleeding, papiloedema. Visceral leishmaniasis Post Kalazar Dermal leishmaniasis (PKDL):- After treatment Allergic reaction (type 3) local HSR or arthus reaction. C/F: skin nodules and hyper pigmentation.