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Leishmaniasis

Leishmaniasis

Leishmania donovani (complex)

Leishmania donovani (complex)

(VL)

(VL)

Leishmania tropica (CL)

Leishmania tropica (CL)

Leishmania major (CL)

Leishmania major (CL)

Leishmania aethiopica (CL)

Leishmania aethiopica (CL)

Leishmania mexicana (Complex)

Leishmania mexicana (Complex)

(CL)

(CL)

Leishmania brazilliensis (complex)

Leishmania brazilliensis (complex)

(MCL)

(MCL)

Leishmania peruriana

Leishmania peruriana

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The Parasite

The Parasite

•

Phylum

Phylum

•

Order

Order

•

Family

Family

•

Genus

Genus

Sarcomastigophor

Sarcomastigophor

a

a

Kinetoplastida

Kinetoplastida

Trypanosomatidae

Trypanosomatidae

Leishmania

Leishmania

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Morphology

Morphology

•

Promasitogte

Promasitogte

•

Insect

Insect

•

Motile

Motile

•

Midgut

Midgut

•

Amastigote

Amastigote

•

Mammalian

Mammalian

stage

stage

•

Non-motile

Non-motile

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Intracellular

Intracellular

Digenetic Life Cycle

Digenetic Life Cycle

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Morphology

Morphology

•

Promastigote

•

Amastigote

Flagella

Kinetoplast

Golgi

Nucleus

Cytoskeleton

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Promastigote

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•

Amastigotes
(*) of
Leishmania
donovani in
the cells of a
spleen.  The
individual
amastigotes
measure
approximately
1 µm in
diameter. 

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Amastigote

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•

Amastigotes of
Leishmania in a
macrophage
from a lymph
node of a dog. 

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•

Leishmania
(Leishman-
Donovan or LD
bodies). Lying in
macrophage cells
from liver.
Giemsa. ×12000.
Enlarged by 9.6.

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•

A
macrophage
filled with
Leishmania
amastigotes.

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Life cycle

Life cycle

•

The organism is transmitted by the bite of

The organism is transmitted by the bite of

several species of blood-feeding sand flies

several species of blood-feeding sand flies

(Phlebotomus) which carries the promastigote

(Phlebotomus) which carries the promastigote

in the anterior gut and pharynx. It gains

in the anterior gut and pharynx. It gains

access to mononuclear phagocytes where it

access to mononuclear phagocytes where it

transform into amastogotes and divides until

transform into amastogotes and divides until

the infected cell ruptures. The released

the infected cell ruptures. The released

organisms infect other cells. The sandfly

organisms infect other cells. The sandfly

acquires the organisms during the blood meal,

acquires the organisms during the blood meal,

the amastigotes transform into flagellate

the amastigotes transform into flagellate

promastigotes and multiply in the gut until the

promastigotes and multiply in the gut until the

anterior gut and pharynx are packed. Dogs

anterior gut and pharynx are packed. Dogs

and rodents are common reservoirs.

and rodents are common reservoirs.

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Mammalian Hosts

Mammalian Hosts

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Rodents

Rodents

•

Gerbils

Gerbils

•

Hyraxes

Hyraxes

•

Bats

Bats

•

Porcupines

Porcupines

•

Opossums

Opossums

•

Sloths

Sloths

•

Primates

Primates

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Dogs

Dogs

•

Foxes

Foxes

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Anteaters

Anteaters

•

. . . .

. . . . .

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Vectors

Vectors

Phlebotomine Sandflies

Phlebotomine Sandflies

6 genera world wide distribution

6 genera world wide distribution

Phlebotomus & Lutzomia

Phlebotomus & Lutzomia

500 species

500 species

Females Haematophagus

Females Haematophagus

Males sap feeders

Males sap feeders

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Clinical Disease

•

Visceral

• Fatal (90%

untreated)

• Liver
• Spleen
• Bone marrow

•

Cutaneous

• Generally Self-

healing

• Skin
• Mucous membranes

SPECTRUM OF DISEASE

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Initial Infection

•

Similar in all species

•

Inoculation of promastigotes

•

Inflammation & chemotaxis

•

Receptor mediated
phagocytosis

Promastigote

Amasitgote

Transformation

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Parasite Spread

Parasite Spread

Macrophage lysis & parasite

Macrophage lysis & parasite

release

release

Lymphatic spread

Lymphatic spread

Blood spread

Blood spread

Target organs

Target organs

Skin/lymph nodes/spleen/liver/

Skin/lymph nodes/spleen/liver/

bone marrow

bone marrow

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Visceral Leishmaniasis

Visceral Leishmaniasis

•

1903

1903

•

1920

1920

•

1931

1931

William Leishman

William Leishman

Pentavalent antimony

Pentavalent antimony

Experimental

Experimental

transmission

transmission

Leishmania donovani (Complex)

Leishmania donovani (Complex)

L.d. archibaldi - L.d.chagasi - L.d.donovani - Ld.infantum

L.d. archibaldi - L.d.chagasi - L.d.donovani - Ld.infantum

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VL - Clinical

VL - Clinical

Manifestation

Manifestation

Variable - Incubation 3-100+ weeks

Variable - Incubation 3-100+ weeks

Lowgrade fever

Lowgrade fever

Hepato-splenomegaly

Hepato-splenomegaly

Bone marrow hyperplasia

Bone marrow hyperplasia

Anemia, Leucopenia & Cachexia

Anemia, Leucopenia & Cachexia

Hypergammaglobulinnemia

Hypergammaglobulinnemia

Epistaxis , Proteinuria, Hematuria

Epistaxis , Proteinuria, Hematuria

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•

Profile view of a
teenage boy
suffering from
visceral
leishmaniasis.
The boy exhibits
splenomegaly,
distended
abdomen and
severe muscle
wasting. 

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•

A 12-year-old
boy suffering
from visceral
leishmaniasis.
The boy
exhibits
splenomegaly
and severe
muscle wasting.

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•

Jaundiced
hands of a
visceral
leishmaniasis
patient. 

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Enlarged spleen
and liver in an
autopsy of an
infant dying of
visceral
leishmaniasis.

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Post Kala Azar Dermal

Post Kala Azar Dermal

Leishmanoid

Leishmanoid

Normally develops <2 years

Normally develops <2 years

after recovery

after recovery

Recrudescence

Recrudescence

Restricted to skin

Restricted to skin

Rare but varies geographically

Rare but varies geographically

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Cutaneous leishmaniasis

of the face. 

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A cutaneous leishmaniasis

lesion on the arm.

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INFECTION

INFECTION

Sub-clinical or inapparent

Sub-clinical or inapparent

infection

infection

Recovery Death

Immune to reinfection Concurrent

infection

PKDL

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Diagnosis

Diagnosis

Clinical signs & symptoms

Clinical signs & symptoms

Hypergammaglobulinemia

Hypergammaglobulinemia

ELISA/Formol gel

ELISA/Formol gel

Bone marrow biopsy

Bone marrow biopsy

Spleen or liver biopsy

Spleen or liver biopsy

Culture & Histology

Culture & Histology

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Speciation

Speciation

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Similar morphology

Similar morphology

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Isoenzyme profiles -

Isoenzyme profiles -

Zymodemes

Zymodemes

•

Monoclonal antibodies

Monoclonal antibodies

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DNA hybridisation - PCR

DNA hybridisation - PCR

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Treatment

Treatment

Good nursing

Good nursing

Diet

Diet

Antibiotics

Antibiotics

Pentavalent antimony

Pentavalent antimony

Pentamidine

Pentamidine

New drugs - New delivery

New drugs - New delivery

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Control

Control

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Vector control

Vector control

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Reservoir control

Reservoir control

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Treatment of active cases

Treatment of active cases

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Vaccination

Vaccination