2. Leishmania
โข There are three Leishmania species which
are parasite in man, L. donovani, L. tropica
& L. brasiliensis.
โข There is not much morphological difference
in these three species.
3. Leishmania donovani
โข Geographical Distribution
1. It is endemic in many places in America, Africa,
China, South Europe and India .
2. In India it is common in Assam, Bengal, Orissa,
Tamil Nadu and eastern parts of Uttar Pradesh
upto Lucknow
4. Habitat
โข Reticuloendothelial system especially
spleen, liver, bone marrow, intestinal
mucosa.
โข Endothelial cells of kidneys, lungs,
meninges, CSF, macrophages of intestinal
wall
6. Morphology
โข Exists in two forms:
1. Leishmanial/Amastigote form/Aflagellar Stage/:
โข It is found as an intracellular parasite in the cell of
endothelial system.
โข It is round in shape, the blepharoplast and
parabasal body are situated at right angles to the
nucleus.
โข From the blepharoplast, a delicate filament
axoneme extends representing the root of the
flagellum.
โข Alongside the axoneme is a clear space vacuole.
8. 2. Leptomonad /Promastigote form/Flagellar
Stage:
โข It is found only in the insect vector Sand Fly.
โข The undeveloped forms are small and pear shaped
while the developed forms are long and spindle
shaped.
โข Blepharoplast and parabasal body are situated in
front of the nucleus.
โข Along flagellum sometimes longer than the body
arises from the blepharoplast.
9.
10. Mode of Transmission
โข Bite of sandfly (Phlebotomus)
โข Mother to fetus
โข Blood transfusion
โข Accidental inoculation of culture in the
laboratory
11. Life Cycle
โข 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.
โข It gains access to mononuclear phagocytes where it
transform into amastogotes and divides until the infected
cell ruptures.
โข 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.
โข Dogs and rodents are common reservoirs.
18. Cutaneous Leishmaniasis
Diagnosis:
โข Smear: Giemsa stain โ microscopy for LD
bodies (amastigotes)
โข Biopsy: microscopy for LD bodies or culture
in NNN medium for promastigotes
19. Treatment
โข No treatment โ self-healing lesions
โข Medical:
o Pentavalent antimony (Pentostam), Amphotericin B
o +/- Antibiotics for secondary bacterial infection.
โข Surgical:
o Cryosurgery
o Excision
o Curettage
20. Visceral leishmaniasis
โข There are geographical variations.
โข The diseases is called kala-azar
โข Leishmania infantum mainly affect children
โข Leishmania donovani mainly affects adults
21. Presentation
โข Fever
โข Splenomegaly, hepatomegaly, hepatosplenomegaly
โข Weight loss
โข Anaemia
โข Epistaxis
โข Cough
โข Diarrhoea
โข Untreated disease can be fatal
โข After recovery it might produce a condition called
post kala-azar dermal leishmaniasis (PKDL)
22. Untreated disease can be fatal
After recovery it might produce a condition
called post kala-azar dermal leishmaniasis
(PKDL)
27. (2) Immunological Diagnosis:
โข Specific serologic tests: Direct Agglutination
Test (DAT), ELISA, IFAT
โข Skin test (leishmanin test) for survey of
populations and follow-up after treatment.