Manoj Mahato

1. LEISHMANIA DONOVANI
MR.MANOJ MEHTA -CLINICALMICROBIOLOGIST

2. The parasite was named by Ronald Ross in 1903 after the Scottish
pathologist William Boog Leishman.
In 1901, Leishman identified the organism in smears taken from the
spleen of a patient who had died from ‘dum-dum fever’.
This disease was similar to what Indian physicians called kala-azar
(black fever).
Initially, these organisms were considered to be trypanosomes.
In 1903, Captain Charles Donovan described them as being new.
These new microorganisms were given the name ‘Leishman-Donovan
bodies’
After that taxonomically designated Leishmania donovani
HISTORY

3. Most of the affected countries are in the tropics and subtropics.
More than 90 percent of the world's cases of visceral leishmaniasis are in India, Bangladesh, Nepal,
Sudan, and Brazil.
Leishmaniasis is found in
 Asia (not Southeast Asia),
Central America,
 South America (not in Uruguay, Chile, or Canada),
Southern Europe (not common in travelers to southern Europe),
The Middle East, and Africa (particularly East and North Africa
GEOGRAPHICAL DISTRIBUTIONS

4. Ninety per cent of Visceral Leishmaniasis cases are found in Bangladesh, Brazil, India, Nepal
and Sudan
Currently, leishmaniasis occurs in 4 continents and is considered to be endemic in 88
countries, 72 of which are developing countries.
 Found on every continent except Australia and Antarctica.
 Annual incidence of disease= 600,000 cases per year.
 People infected worldwide=12 million.
People at risk=350 million
90 % of cases with Cutaneous Leishmaniasis occur in Afghanistan, Algeria, Brazil, Iran, Peru,
Saudi Arabia and Syria.
EPIDEMIOLOGY

5. The major risk factor is being exposed to infected sand flies.
Infection is more common in adventure travelers, Corps workers, soldiers
WHO IS AT RISK ?

6. Kingdom: Protista
Subkingdom: Sarcomastigophora
Phylum: Protozoa
Subphylum: Mastigophora
Class: zoomastigophora
Order: Kinetplastida
Genus: Leishmania
Species: donovani, tropica, Mexicana,braziliensis, etc
CLASSIFICATION

7. Leishmaniasis is a vector borne disease caused by protozoan parasites of to the genus
Leishmania and is transmitted by the bite of sand fly.
This disease is also known as kala azar, black fever, sandfly disease, Dum-Dum fever.
Kala-azar means dark pigmentation which is characteristic of cases of visceral leishmaniasis.
It is caused by Leishmania donovani bodies and may be present either in endemic, epidemic or
sporadic forms.
It iswidely prevalent in India in epidemic form in states of Bihar, Assam and Bengal,Tarai of
Nepal.
Kala azar found in East and North Africa is a disease of young children and young adults,
being more common in males as compared to females.
KALA AZAR

8. Mainly by the bite of Female Sand Fly (Phlebotomus argentipus)
-Genus Phlebotomus(in old world)
-Genus Lutzomyia(in new world)
Blood transfusion
Accidental inoculation from culture
MODE OF TRAMSMISSION

9. The parasite exists in 2 forms;-
1. Amastigotes: a flagellar stage
2. Promastigotes: flagellar stage
MORPHOLOGY

10. A flagellar stage
Infective stage for sand fly.
Occurs in the vertebrate host
Habitat: Found in R.E. system of vertebrate host (Man, Dog & hamster).
divides by binary fission at 37oC.
Shape: Round /Oval
Size: 2-4 mm, along longitudinal axis.
Has following components:
Cell membrane
Nucleus relatively larger and situated centrally.
Kinetoplast situated right angle to nucleus.
AMASTIGOTE STAGE(LEISHMANIAL FORM)

11. Flagellar stage
Infective stage for Man.
Occurs in the Sandflies and Culture
divides by binary fission at 27oC.
They are spindle shaped ;15-20 μm in length & 1-2μm in width.
Nucleus smaller and situated in the middle of the cell or along the side of cell-wall.
Kinetoplast lies transversely near the anterior end.
Free anterior flagellum
Kinetoplast at the anterior end of the body.
There is no undulating membrane.
PROMASTIGOTE: (LEPTOMONAD STAGE)

12. TYPES OF LEISHMANIASIS
Visceral leishmaniasis
 Kala-azar,
 Black fever
 Dum-Dum fever,
 Sahib’s disease
 Kala Dukh
 White leprosy
Cutaneous leishmaniasis
 Aleppo boil,
 Baghdad boil,
 Delhi boil,
 Kandahar sore,
 Lahore sore,
 Oriental sore,
Mucocutaneous Leishmaniasis
 Breda's disease
 bosch yaws,
 bush yaws
 forest yaws

13. Life Cycle Stages: Amastigote and Promastigote
Host: Two Hosts
oHuman(definitive): Amastigote forms found in man reticuloendothelial cells of spleen,
bone marrow, Liver, intestinal mucosa,mesentric lymph node.
Sand Fly(intermediate): Promastigote forms found in sand fly
Vector: Sand Fly
Reservoir Host: Dog(China&Brazil),Man(India),Rodents(Africa)andJackals(Russia).
Infective Form: Promastigote
Pathogenic Form: Amastigote
Route of Infection: Penetration through skin by the bite of female sandflies.
Site of Localization: Mononuclear phagocyte system/R.E.system.
LIFE CYCLE OF LEISHMANIA DONOVANI

14. LIFE CYCLE OF LEISHMANIA DONOVANI

15. LIFE CYCLE OF LEISHMANIA DONOVANI

16. -Promastigote is the infective form which is introduced into human body by bite of sand fly in which the
promastigote has been developed.
-Some of the promastigotes are destroyed by body’s immune system. Some others take refuge inside
the cells of Re-system ,where they are changed into amastigote form and undergo multiplication by
binary fission.
-When the cells become packed with parasites, they rupture releasing the parasites into circulation from
where they are again engulfed by or invade cells of RE system.
-The cycle is repeated and entire RE system is progressively infected.
Some of the free parasites in circulation are engulfed by neutrophils and monocytes(Macrophage).
-During blood meal, the vector(sand fly) draws free as well as those parasites inside the monocyte.
LIFE CYCLE OF LEISHMANIA DONOVANI

17. -In sand fly, the amastigotes are changed into promastigote sand multiply enormously by
binary fission in them id gut and forwards to the pharynx and buccal cavity. Between 6th
to 9th day of infection, heavy pharyngeal infection is observed. This type of development
is known as anterior station development.
-When this sand fly bites a man, transmission is effected.
LIFE CYCLE OF LEISHMANIA DONOVANI

18. Low grade fever continuous / intermittent
Hepato-splenomegaly
RE system affected
Bone marrow hyperplasia
Anemia , Leucopenia
Hypergammaglobulinnemia
Epistaxis , Proteinuria, Hematuria
If left untreated ....Fatal 75-95%
Complications:- pneumonia, TB, dysentery, uncontrolled haemorrhage
Prognosis:- With an early treatment, cure rate >90%
If not treated, death occurs within 2 years
SIGN AND SYMPTOMS OF VISCERAL LEISHMANIASIS

19. Incubation Period : 3-6 months
Inoculation of Promastigotes in skin
Ingestion of Promastigote by Neutrophils
Attraction of macrophages
Ingestion of infected neutrophil, Amastigote formation in Macrophage.
Invasion by Plasma cells and lymphocytes.
Amastigotes liberated in circulation after rupture RE cells proliferate, heavily parasitized
PATHOGENESIS OF LEISHMANIA DONOVANI

20. LABORATORY DIAGNOSIS OF LEISHMANIA DONOVANI

21. Microscopy: slit-skin smear, splenic aspirate, liver biopsy or bone marrow biopsy. -
-Examination of Giemsa and Leishman stained slides of the relevant tissue is still
the technique most commonly used to detect the parasite.
Peripheral blood by thick film method.
LABORATORY DIAGNOSIS OF LEISHMANIA DONOVANI
Amastigotes in a macrophage

22. Culture: Novy Mac Neal, later modified by Nicolle (N.N.N.)medium
-The aspirates can be cultured in NNN. In culture the amastigote stage converts to the
promastigote stage.
2 parts of salt agar , 1 part defibrinated Rabbit blood, Ascorbic acid and Haematin
Specimen inoculated in water of condensation 22°C – 24°C,
This is not a rapid technique, as the parasites may take from 10 - 21 days to grow.
Least sensitive, Long time
LABORATORY DIAGNOSIS OF LEISHMANIA DONOVANI
Promastigote
Promastigote from culture in NNN medium

23. Serodiagnosis: VL produces large amounts of specific IgG which can be used for
diagnosis. Currently the most used sero diagnostic tests Enzyme Linked Immunosorbent
Assay (ELISA).
Molecular techniques: PCR, such technique, however, are not readily available in general
diagnostic laboratories
LABORATORY DIAGNOSIS OF LEISHMANIA DONOVANI

24. Blood count : Neutropenia, Relative Lymphocytosis, Leucopenia,Anaemia
(raised ESR)
Serological Tests :
Aldehyde ( Formal gel) Test (Napier): To detect gamma globulin
Antimony test : Increase in globulin levels ( Not used now)
Complement Fixation Test : UtilisesW.K.K. antigen
Klinenstein and Kuhn:Early diagnosis ( Not used now )
LABORATORY DIAGNOSIS OF LEISHMANIA DONOVANI

25. rK39
Rapid dipstick test
Based on the recombinant k39 protein, a 39-amino acid cloned in Escherichia
coli, from the C terminus of the kinesin protein of Leishmania major in India
LABORATORY DIAGNOSIS OF LEISHMANIA DONOVANI

26. LABORATORY DIAGNOSIS OF LEISHMANIA DONOVANI
DIRECT AGGLUTINATION TEST (DAT)
o Semi-quantitative test
o Microtitre plates : increasing dilutions of patient's serum or blood is
mixed with stained killed L. donovani promastigotes.
o Agglutination visible after 18 hours
o A titre greater than 1:3200 is positive

28. Education in the community about the causes and modes of transmission of leishmaniasis
Reduction of sand fly population by insecticides mainly DDT,dieldrin, malathion
Reduction of reservoir by killing all the infected dogs in the cases of zoonotic kala-azar
Prevention of exposure to sand fly using insect repellent, bed nets and window mess as needed
Wearing protective clothing
There are no vaccines or drugs that prevent leishmaniasis
PREVENTION AND CONTROL