Transcript Promastigote

Leishmania Parasites and Diseases
SPECIES
Disease
Leishmania tropica major
Leishmania tropica minor Cutaneous leishmaniasis
Leishmania aethiopica
Leishmania mexicana
Leishmania braziliensis
Mucocutaneous leishmaniasis
Leishmania donovani
Leishmania infantum
Visceral leishmaniasis
Morphology
Digenetic Life Cycle
• Promasitogte
• Insect
• Motile
• Midgut
• Amastigote
• Mammalian stage
• Non-motile
• Intracellular
Promastigotes of Leishmania
Amastigote of Leishmania
Promastigote and amastigote
• Promastigote:
• Vector phase
• Reside in the gut of sandfly
• Spindle shaped with 1 free flagellum
• Nucleus; cytoplasm; kinetoplast; basal
body; rhizoplast
• Chrysanthemum-like in culture
medium
Promastigote
• Amastigote (leishman-donovan body):
• Human phase, reside in macrophage
• Very, very minute elliptical body
• No free flagellum
• Nucleus: deep red, located at one side
• Cytoplasm: blue (after right stain)
• Kinetoplast: basal body; rhizoplast
Amastigotes of Leishmania
Main Points of Life Cycle
• Host: man and sandfly
• No sexual development in the host
• Residing site: macrophage
• Infective stage: promastigote
• Diagnostic stage: Amastigote
• Infective route: inoculation of sandfly
• Reservoir host: dog
• Infection could also via transfusion
Clinical Disease
• Visceral
• Fatal (90%
untreated)
• Liver
• Spleen
• Bone
marrow
• Cutaneous
• Generally Selfhealing
• Skin
• Mucous
membranes
Parasite Spread
Macrophage lysis & parasite release
Lymphatic spread
Blood spread
Target organs
Skin / lymph nodes /spleen / liver/
bone marrow
Clinical Spectrum of Leishmaniasis
Cutaneous Leishmaniasis (CL)
most common form, relatively benign self-healing skin
lesions (aka, localized or simple CL)
Mucocutaneous Leishmaniasis (MCL)
simple skin lesions that metastasize to mucosae
(especially nose and mouth region)
Visceral Leishmaniasis (VL)
generalized infection of the reticuloendothelial system,
high mortality
Clinical types of cutaneous leishmaniasis
• Leishmania major: wet lesions with severe
reaction
• Leishmania tropica: : Dry lesions with
minimal ulceration
Oriental sore (most common) classical selflimited ulcer
lesion
Cutaneous leishmaniasis of the
face.
A cutaneous leishmaniasis lesion
on the arm.
Diffuse cutaneous leishmaniasis
Leishmaniasis recidiva
Leishmanioma is rarely seen at
the site of bite
Via blood
stream to
Reticulo-endothelial cells
Promastigotes
present in human viscera
Liver: hepatomegaly
Spleen: splenomegaly
Lymph nodes: enlarged
Bone marrow: Anaemia, leukopenia,
thrombocytopenia
Reversal of albumin / globulin ratio
Intestinal mucosa: diarrhoea &
dysentey
Fever: intermittent with double daily rise.
Also called Dum-dum fever (Dum-dum is a
town in Calcutta in India)
• Jaundiced hands of a
visceral leishmaniasis
patient.
Clinical Picture of Visceral Leishmaniasis
Skin changes
Dark pigmentation or depigmentation (butterfly
pigmentation)
(also called Kala azar means black fever)
Post kala azar dermal leishmanoid (PKDL)
Skin nodules.
Skin changes in visceral leishmaniasis
Butterfly pigmentation
Post Kala-Azar dermal leishmanoid
Usually occur in patients from the old
world
Depigmented areas
Diagnosis of
C. Leishmaniasis
Clinically:
Ulcer with sharp cut indurated
margin
Microscopy:
To detect amastigotes
at the edge of the
ulcer by aspiration
or biopsy
Culture:
To detect promastigotes
Serological tests
V. Leishmaniasis
Clinically:
Fever,
hepatosplenomegaly
Microscopy:
To detect
amastigotes in
blood, liver, spleen,
lymph node, bone
marrow
Culture:
To detect
promastigotes
Animal inoculation
Serological tests
Mucocutaneous leishmaniasis
Treatment Of Cutaneous Leishmaniasis
• Medical:
o Pentavalent antimony (Pentostam),
Amphotericin B
o Antifungal drugs
o +/- Antibiotics for secondary bacterial infection.
• Surgical:
o Cryosurgery
o Excision
o Curettage