Leishmaniasis

1
Leishmaniasis

• Leishmania donovani (complex) (VL)
• Leishmania tropica (CL)
• Leishmania major (CL)
• Leishmania aethiopica (CL)
• Leishmania mexicana (Complex) (CL)
• Leishmania brazilliensis (complex) (MCL)
• Leishmania peruriana

2
The Parasite

• Phylum
• Order
• Family
• Genus

• Sarcomastigophora
• Kinetoplastida
• Trypanosomatidae
• Leishmania

3
Morphology
Digenetic Life Cycle

• Promasitogte
• Insect
• Motile
• Midgut

• Amastigote
• Mammalian stage
• Non-motile
• Intracellular

4
Morphology

• Promastigote

• Amastigote

Flagella Kinetoplast Golgi Nucleus Cytoskeleto
n
5
Promastigote
6

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

7
Amastigote
8

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

9

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

10

• A macrophage filled with Leishmania amastigotes.

11
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.

12
(No Transcript)
13
Mammalian Hosts

• Rodents
• Gerbils
• Hyraxes
• Bats
• Porcupines
• Opossums

• Sloths
• Primates
• Dogs
• Foxes
• Anteaters
• . . . . .

14
Vectors

• Phlebotomine Sandflies
• 6 genera world wide distribution
• Phlebotomus Lutzomia
• 500 species
• Females Haematophagus
• Males sap feeders

15
(No Transcript)
16
Clinical Disease

• Visceral
• Fatal (90 untreated)
• Liver
• Spleen
• Bone marrow

• Cutaneous
• Generally Self- healing
• Skin
• Mucous membranes

SPECTRUM OF DISEASE
17
Initial Infection

• Similar in all species
• Inoculation of promastigotes
• Inflammation chemotaxis
• Receptor mediated phagocytosis

Promastigote
Amasitgote Transformation
18
Parasite Spread

• Macrophage lysis parasite release
• Lymphatic spread
• Blood spread
• Target organs
• Skin/lymph nodes/spleen/liver/
• bone marrow

19
Visceral Leishmaniasis

• 1903
• 1920
• 1931

• William Leishman
• Pentavalent antimony
• Experimental transmission

Leishmania donovani (Complex) L.d. archibaldi -
L.d.chagasi - L.d.donovani - Ld.infantum
20
VL - Clinical Manifestation

• Variable - Incubation 3-100 weeks
• Lowgrade fever
• Hepato-splenomegaly
• Bone marrow hyperplasia
• Anemia, Leucopenia Cachexia
• Hypergammaglobulinnemia
• Epistaxis , Proteinuria, Hematuria

21

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

22

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

23

• Jaundiced hands of a visceral leishmaniasis
  patient. 

24

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

25
Post Kala Azar Dermal Leishmanoid

• Normally develops lt2 years after recovery
• Recrudescence
• Restricted to skin
• Rare but varies geographically

26
Cutaneous leishmaniasis of the face. 

27
A cutaneous leishmaniasis lesion on the arm.
28
INFECTION

• Sub-clinical or inapparent infection

Recovery
Death Immune to reinfection
Concurrent infection PKDL
29
Diagnosis

• Clinical signs symptoms
• Hypergammaglobulinemia
• ELISA/Formol gel
• Bone marrow biopsy
• Spleen or liver biopsy
• Culture Histology

30
Speciation

• Similar morphology
• Isoenzyme profiles - Zymodemes
• Monoclonal antibodies
• DNA hybridisation - PCR

31
Treatment

• Good nursing
• Diet
• Antibiotics
• Pentavalent antimony
• Pentamidine
• New drugs - New delivery

32
Control

• Vector control
• Reservoir control
• Treatment of active cases
• Vaccination