1. Leishmaniasis

2. Lecture Objectives
By the end of this lecture the student is expected to be able to:
Know different stages of Leishmania parasites
Describe life cycle of Leishmania parasites
Discuss what diseases caused by Leishmania parasites and what is endemic in Saudi Arabia.
Geographical distribution of Leishmania in the world either cutaneous or visceral Leishmaniasis
Know what are the vectors of Leishmania
Discuss clinical types of Leishmaniasis
Know uncommon types of the diseases
How Leishmaniasis is diagnosed in the labs
What is the best treatment for Leishmaniasis

3. Different stages of Haemoflagellates

4. Different stages of Leishmania
Promastigotes of Leishmania
Amastigote of Leishmania

6. Leishmania Life Cycle
Right side of figure describes the stages within the human (blue arrows).
Humans are infected at step 1 when the sandfly bites human and injects promastigotes.
Sandfly is infected at step 5 when it ingests macrophages containing amastigotes in human blood.
Left side of figure describes the stages within the sand fly (red arrows).
(Provider: Centers for Disease Control and Prevention/Dr. Alexander J. da Silva and Blaine Mathison.)

7. Digenetic Life Cycle Promastigote Amastigote – Insect
– Motile
– Midgut
Amastigote
– Mammalian stage
– Non-motile
– Intracellular

8. Leishmania Parasites and Diseases
SPECIES
Cutaneous leishmaniasis
Leishmania tropica*
Leishmania major*
Leishmania aethiopica
Leishmania mexicana
Mucocutaneous leishmaniasis
Leishmania braziliensis
Visceral leishmaniasis
Leishmania donovani*
Leishmania infantum*
Leishmania chagasi
* Endemic in Saudi Arabia

9. Leishmania Geographical distribution

10. Leishmania In Saudi Arabia
Two forms of leishmaniasis are present in KSA.
CL,
Cases of visceral leishmaniasis
(VL) are occasionally reported from South-western zone of KSA, mainly in Jazan and Aseer regions
(Abuzaid A. Abuzaid et al :Cutaneous Leishmaniasis in Saudi Arabia:
A Comprehensive Overview)
Map of the Kingdom of Saudi Arabia showing the distribution of reported cases of CL in 2015 by region.

11. Leishmania In Saudi Arabia
Graph showing the great
drop in number of reported CL cases
in Saudi Arabia over the last 30 years.CL, Cutaneous leishmaniasis.

13. 1- Clinical types of cutaneous leishmaniasis
Leishmania major: Zoonotic cutaneous leishmaniasis: Wet lesions with severe reaction
Leishmania tropica: Anthropozoic cutaneous leishmaniasis: Dry lesions with minimal ulceration
Oriental sore (most common) classical self-limited ulcer

14. Clinical types of cutaneous leishmaniasis
Cutaneous Lishmaniasis the common type:
This starts as a painless papule on exposed parts of the body, generally the face.
The lesion ulcerates after a few months producing an ulcer with an indurate margin.
In some cases the ulcer remains dry and heals readily (dry-type-lesion).
In some other cases the ulcer may spread with an inflammatory zone around, these known as (wet-type-lesion) which heal slowly.

15. (a, b) Two expatriates work in the same farm
presenting with multiple lesions. Abuzaid et al:2017

16. Clinical types of cutaneous leishmaniasis
Uncommon types Cutaneous Lishmaniasis :
1- Diffuse cutaneous leishmaniasis (DCL):
Caused by L. aethiopica, diffuse nodular non-ulcerating lesions, seen in a part of Africa, people with low immunity to Leishmania antigens.
Diffuse cutaneous (DCL), and consists of nodules and a thickening of the skin, generally without any ulceration, it needs numerous parasite.
2- Leishmaniasis recidiva (lupoid leishmaniasis):
Severe immunological reaction to leishmania antigen leading to persistent dry skin lesions, few parasites.

17. Leishmaniasis recidiva
Diffuse cutaneous leishmaniasis (DCL)
Leishmaniasis recidiva

18. 2- Mucocutaneous leishmaniasis
The lesion starts as a pustular swelling in the mouth or on the nostrils.
The lesion may become ulcerative after many months and then extend into the naso- pharyngeal mucous membrane.
Secondary infection is very common with destruction of the nasal cartilage and the facial bone.

19. Diagnosis of cutaneous & muco-cutaneous leishmaniasis
The parasite can be isolated from the margin of the ulcer.
A diagnostic skin test, known as Leishmanin test (Montenegro Test), is useful.
Smear: Giemsa stain – microscopy for LD bodies (Leishman- Donovan bodies, amastigotes).
Skin biopsy: microscopy for LD bodies or culture in NNN medium for promastigotes
NNN medium

20. Treatment of cutaneous & muco-cutaneous leishmaniasis
No treatment – self-healing lesions
Medical:
Pentavalent antimony (Pentostam), Amphotericin B
Antifungal drugs
+/- Antibiotics for secondary bacterial infection.
Surgical:
Cryosurgery
Excision
Curettage

21. 3- Visceral leishmaniasis
There are geographical variations.
The disease is called kala-azar
Leishmania infantum mainly affect children
Leishmania donovani mainly affects adults.
The incubation period is usually 4-10 months.
The early symptoms are generally low grade fever with
malaise and sweating.
In later stages, the fever becomes intermittent and their can be liver enlargement or spleen enlargement or hepatosplenomegally because of the hyperplasia of the lymphoid – macrophage system.
Hepatosplenomegaly in visceral leishmaniasis

22. 3- Visceral leishmaniasis
Clinical Findings
Fever
Splenomegaly, hepatomegaly, hepatosplenomegaly
Weight loss
Anaemia
Epistaxis
Cough
Diarrhoea
Untreated disease can be fatal
After recovery it might produce a condition called
post kala-azar dermal leishmaniasis (PKDL)

23. Diagnosis of Visceral leishmaniasis
Parasitological diagnosis: Method
Bone marrow aspirate microscopy (LD bodies)
Splenic aspirate culture in NNN medium
(promastigotes)
Lymph node
Tissue biopsy

24. Bone marrow aspiration
Bone marrow amastigotes

25. Diagnosis of Visceral leishmaniasis
(2) Immunological Diagnosis:
Specific serologic tests: Direct Agglutination Test (DAT), ELISA,
Direct agglutination test (DAT): based on agglutination of the trypsenized whole promastigotes is useful in endemic regions.
Itssensitivity ranges from % and specificity from 72 to 100%.
ELISA is an important sero diagnostic tool for leishmaniasis.
It is a highly sensitive test and its specificity depends upon the antigen used.
Skin test (leishmanin test) for survey of populations and follow-up after treatment
ELISA
DAT

26. Treatment of Visceral leishmaniasis
Recommended treatment varies in different endemic areas:
Pentavalent antimony- sodium stibogluconate (Pentostam)
Amphotericin B
Treatment of complications:
Anaemia
Bleeding
Infections etc

27. References
Murray P, Rosenthal K, Pfaller M, (2013). Medical Microbiology: Study smart with Student Consult. 7th ed.Elsevier. Chapters : 74
Levinson WE (2010). Review of Medical Microbiology and Immunology. Eleventh-Edition, McGraw-Hill Publisher, UK. Chapters: 52.
Abuzaid A. Abuzaid et al. 2017:Cutaneous Leishmaniasis in Saudi Arabia: A Comprehensive Overview.