Lecture 52 - 3rd Asessment - Lei Sh Mania

LEISHMANIA MORPHOLOGY: Amastigote, pro, epi-, trypomastigote. Indistinguishable in Leishmania sp. from Trypanosoma sp. LIFE CYCLE: Phlebotomus sp. injects promastigotes (contamination). Macrophages engulf, amastigotes multiply, (L. tropica, L.mexicana) viscera (L.donovani),

rupture,

spread.

Parasites localize in skin

mucocutaneous (L. braziliensis ) ,

Sandfly feeds,

take up amastigotes, flagellates in gut, block pharynx, dislodged at subsequent blood meal (8 to 20 days). NOTE: Many strains, species, subspecies. Classification by isoenzyme patterns. Cutaneous Leishmaniasis: GEOG. DISTRIBUTION: Kuwait,

Urban

Rural ME.

MORPHOLOGY: Amastigote: Nucleus

kinetoplast

cytoplasm

Skin

LIFE CYCLE: Animal reservoirs PATHOLOGY: Bite of fly,

cellular infiltration of dermal layers.

Parasites in

macrophages and histiocytes, papule/nodule/ulcer.

Immunity.

CLINICAL SYMPTOMS/SIGNS: Incubation 1-2 weeks, crusted ulcer,

offensive pus.

Sores may heal,

papule,

induration, scar formation,

lesions may be dry / wet type. EPIDEMIOLOGY: Reservoir hosts LAB DIAGNOSIS: Amastigote, Aspirate from healthy margin of ulcer. Culture in 4N medium - promastigotes.

Biopsy ?

TREATMENT: Pentamidine locally and systemically. IMMUNE RESPONSE:

Homologous strain

CMI

Visceral Leishmaniasis GEOG. DISTRIBUTION: Kuwait (?), China,

Saudi Arabia,

ME,

India,

Central and South America,

Sudan.

MORPHOLOGY: Same but disease has geographic variants. LIFE CYCLE: Parasites in RE,

Animal reservoirs.

EPIDEMIOLOGY: Children: Med Basin, West and Central Asia, China. Dog. Man/Children: Indian subcontinent. No reservoir. Man: Sudan. Resistant to treatment. Rodents IMPORTANCE: 12 million cases; 400,000 new cases pa; mortality 20,000, underestimate. PATHOLOGY: Parasites in blood but many in liver, spleen, hyperplasia of reticular cells.

lymph-node,

CLINICAL SYMPTOMS/SIGNS: Incubation period. Fever (double daily rise) Chills/sweating.

Diarrhoea,

Patient looks good/appetite, Later-weight loss,

enlarged spleen / liver. Secondary infections: Leukopenia, Albumin/globulin ratio Skin changes,

Die in 2 years.

LAB DIAGNOSIS: Smear, Culture, agglutination (using cultured promastigotes). TREATMENT: Pentamidine

Serology? IFAT, Direct

PREVENTION: Spraying / malaria.

Mucocutaneous Leishmaniasis: (South Central American) GEOG. DISTRIBUTION: MORPHOLOGY: Amastigotes, mexicana) LIFE CYCLE: Animal Reservoir hosts

promastigotes (L. braziliensis, L.

PATHOLOGY: Bite, papule, ulcer (elevated indurated margin). Regional lymphadenopathy

Metastasize:

CLINICAL SYMPTOMS/ SIGNS: Cutaneous develops to mucocutaneous. Pain Lesions cause deformity. Diffuse cutaneous leishmaniasis. DIAGNOSIS: Organisms from lesions. Culture

Biopsy.

Intradermal test.

TREATMENT: Pentamidine and Amphotericin B. IMMUNITY IN LEISHMANIASIS:

ENTOMOLOGY OF LEISHMANIASIS Phlebotomus sp. and Lutzomyia sp. (Sandflies) MORPHOLOGY: Slender hump backed

small

HABITS: Female

nocturnal feeders

Eggs, larva,

piercing mouthparts

hairy

warm/humid

pupa - blood meal essential.

PATHOGENICITY: Bite: Papule, sensitive

raised wings at rest

patients,

DISEASE: Leishmania,

erythema, nausea,

pain and itch, fever

malaise

Sandfly fever (Transovarial transmission),

Bartonella

Life Cycle

Geographic Distribution

Clinical

Diagnosis