1. LEISHMANIA HUMAN PATHOGENS Leishmania tropica Leishmania major
Leishmania donovoni
Leishmania mexicana
Leishmania braziliensis

2. Classification Domain: Eukaryota Kingdom: Protista
Phylum: Mastigophora
Class: Kinetoplastida
Order: Trypanosomatida
Genus: Leishmania
Species: donovani , tropica, major, maxima, braziliensis

3. Morphology i.e. Leishmania are heteroxenous
Promastigiote in the gut of the fly
Amastigote in the tissue of the vertebrate
Leishman-Donovan body

4. Morphological terms
Mastigote = flagella
Check the position of the: Nucleus(Nu), Knetoplate(kt), undulating membrane(um) flagella(fg) & basal body(bb)
Amastigote:
Promastigote
Epimastigote
Trypomastigote

5. Examle: Amastigotes of
Morphology
Examle: Amastigotes of
L donovani
10 mm K N H
Indistinguishable from amastigotes of T cruzi
Very small size, and absence of an emergent flagellum or undulating membrane
Amastigotes of L. tropica or L. mexicana from skin lesions and L. braziliensis from mucocutaneous lesions would appear identical

6. Morphology…… Leishmania rosette
In prepared slides you can see promastigotes aligning their nose in a circle, called a rosette.

7. Epidemiology
Leishmania spp cause a major veterinary and public health disease in Latin America, Africa, Asia and the Mediterranean basin where 20-40% of dogs and 1-2% of children are infected
They cause Leishmaniasis a disease affecting about 12 million people
Mainly mammals – humans, dogs, several species of rodents
Found in Africa through the Middle East and Asia
Broadly overlaps the increasing HIV infection areas
Evolving quickly to the population of hosts and vectors where it is found

8. Epidemiology……..
Dogs are main reservoir in the ‘old world’
In dogs Visceral leishmaniasis typically causes cutaneous lesions, with alopecia, depigmentation, hyperkeratosis, in addition to lymphadenopathy, deep visceral organ involvements.

9. Vector of Leishmania spp
Life Cycle……..
Vector of Leishmania spp
Lutzomyia spp. in the Central and South America
(New World). L. mexicana
Phlebotomus spp/
sand flies in Africa,
Asia and Middle East.
L. donovan

10. Genus Lutzomyia diabolica (sand fly)
1 mm
Potential vector of Leishmania mexicana in the New World
This is a non-biting male

11. Genus Phlebotomus (Sand Fly)
Vector for leishmaniasis(old world)

12. Life Cycle Intermediate host and vectors
are the sand flies - ~600 species
Ingest the amastigote form, goes to mid- or hindgut to become promastigote, move to esophagus and pharynx, causes plugs in the digestive system, fly clears to the unsuscpecting host
The vector bite the host or Can be crushed into skin or mucous membrane

13. Life Cycle……..
Mammals
Reticuloendothelial system of spleen, liver, mesenteric LN, intestine and BM
Dividing amastigotes in macrophage by binary fission  burst macrophage  free amastigotes  re-phagocytosed or ingested by fly  dividing promastigotes in fly gut  injected into bite wound, phagocytosed  dividing amastigotes in macrophage

14. Life Cycle
Generally:
It reproduces in the gut of a female sandfly, and migrates to her proboscis (mouth part).
It is introduced into the human by her bite.
It then enters a macrophage and becomes intracellular.
Here, it loses its flagella and is now known as an amastigote.

15. Life cycle ……Leishmaniasis
These amastigotes multiply in various organs including the spleen, liver, and lymph nodes.
Symptoms include hepatosplenomegaly, lymph adenopathy, fever, weight loss, and a decrease in all blood cells: WBC, RBC, and platelets.
The treatment is almost as bad as the disease because of the side effects. It is best to catch it early.

16. Leishmaniasis Life Cycle

18. Immunology and Treatment
Problem is that the parasite lives in the macrophage where it lives in the phagolysome – degrades contents – evades the immune system
Differ markedly in clinical manifestations
Self-healing to fatal
Treatment
May alter clinical manifestastions
Pentavalent antimonials – can be as severe as the disorder

19. L. tropica and L. major
Cause cutaneous ulcer or oriental sore – cutaneous leishmaniasis also called Jericho, Aleppo or Dehli boil
West Central, Middle East and Asia Minor into India

20. Pathogenesis of Lt and Lm
Evidence takes a few days to several months
Small red papule to a spreading ulcer
May heal or become secondarily infected
L tropica – found in more densely populated regions; many amastigotes; persists for months
L major – found in sparsely inhabited areas; rapid ulceration; few amastigotes
Diagnosis comes from finding amastigotes in scrapings from the outer edges of lesion

21. L. donovani Dum-Dum fever or Kala-Azar
Asymptomatic or progressive – 2 to 4 months incubation
Symptoms
Low grade fever, malaise, protruding abdomen due to enlarged spleen/liver and eventual death
Spleen is trying to make macrophages instead of RBC’s
May also be acute – chills, fever to 104F, vomiting and death, also edema of the face, bleeding of mucous membranes, difficulty breathing and diarrhea

22. L. braziliensis Causes espundia, uta or mucotaneous leishmaniasis
Found in Central Mexico and Northern Argentina
Similar to other spesies
Find LD bodies in tissues
Once cured, lifelong immunity; if dormant – may re-occur

23. L. mexicana
North Central America, Mexico, Texas and possibly the Dominican Republic and Trinidad
Cutaneous form, increasing in numbers of infected
3 clinical manifestastions
Cutaneous – Chiclero-ulcer
Nasopharyngeal mucosal – rare manifestation
Visceral – rare manifestation
Sand flies is vector, disease is a zoonosis that has a main reservoir as rodents

24. Cutaneous Leishmaniasis
Parasites form skin ulcers.

25. As many as 200 lesions may form causing disability and social stigma

26. Mucocutaneous Leishmaniasis
Central & South America (new world)
Destroys mucous membranes of nose & mouth

27. Visceral Leishmaniasis Kala Azar
Primarily occurs in Africa and Asia.
Characterized by irregular fever, weight loss, swelling of spleen & liver, & anemia.
Fatality can be 90% if untreated.

28. Diagnosis and Treatment
Males are more susceptible than females
Probably due to the exposure to the sand fly
Find Leishman-Donovan bodies in tissues or secretions
Use monoclonal Ab in ELISA
Dogs are main important reservior in most areas
Oklahoma dog strain is endemic in the USA
Chemotherapy is various antimony compounds

29. Visceral Leishmaniasis
Liver section from a person with
Visceral Leishmaniasis
Higher magnification - showing infected host cells adjacent to uninfected hepatocytes
Low magnification view - showing extensive infection of Kupffer cells by amastigotes

30. Vector - Gut sample -Promastigotes of L. donovani
Stage found in the gut of the sand fly
Undulating membrane is absence
Anterior location of the kinetoplast (K) relative to the nucleus (N) K N

31. SUMMARY

33. TERMS Promastigote: has single flagella Amastigote: has no flagella
Kinetoplast: round mass of circular DNA

34. Leishmania Life Cycle
It starts out as a spindle-shaped, single flagellated cell called a promastigote (mastigote means flagella).
You can also see the nucleus and a kinetoplast (mass of circular DNA).
Kinetoplast

35. Leishmania rosette
In prepared slides you can see promastigotes align their nose in a circle, called a rosette.

36. Leishmaniasis rosette

37. Leishmania donovani (Promastigote)
Single flagellum found in sand flies

38. Leishmaniasis Macrophage rupturing
Amastogotes
Amastogotes with nucleus and kinetoplast

39. Leishmania
Amastigotes

40. Sandfly
This looks like a mosquito, except its body is hairy and the wings are feathery.

41. Leishmaniasis Cutaneous Mucocutaneus Visceral
There are three forms of Leishmaniasis:
Cutaneous
Mucocutaneus
Visceral

42. Cutaneous Leishmaniasis
The disease is only at the site of the bite.
This form is seen in Texas, Mexico, Asia, and the Middle East (our Iraq troops are coming down with this form).
It manifests as a large, wet sore with raised edges. It looks like a volcano with weepy serum coming out of the center.
The wound is not contagious, just the sandfly bite.
Dogs can get this disease, too.

43. Leishmaniasis (cutaneous)

44. Leishmaniasis (cutaneous)

45. Leishmaniasis (cutaneous)

46. Leishmaniasis (mucocunateous)
This is when the disease located in the mucous membranes of the nose and mouth.
The most gruesome photos are of this form.

47. Leishmaniasis (mucocunateous)

48. Leishmaniasis (visceral)
This is the most serious form. It occurs especially in immunocompromised people, especially HIV patients.
The amastagotes reproduce inside macrophages.
Only T-cells can kill infected macrophages, but HIV is a disease that infects T-cells.
This form is known as Kala Azar.

49. Viscera Leishmaniasis
Geographic Distribution: More than 90 percent of the world's cases of visceral leishmaniasis are in India, Bangladesh, Nepal, Sudan, and Brazil.
Leishmaniasis is also found in Mexico, Central America, and South America, southern Europe, Asia, the Middle East, and Africa.

50. Kala Azar
Hepatosplenomegaly

51. Kala Azar (duodenum)

52. African
trypanasomiasis

53. Morphological terms/stages
Mastigote = flagella
Check the position of the: Nucleus(Nu), Knetoplate(kt), undulating membrane(um) flagella(fg) & basal body(bb)
Amastigote:
Promastigote
Epimastigote
Trypomastigote

55. Leishmania
spp