mahesh microbiology

1. Leishmania
Presented by:
Mahesh Yadav
M.Sc. IIYr.
Central Department of Microbiology,T.U

2. INTRODUCTION
• Leishmania is a genus of trypanosomatid
protozoa, which causes a fatal vector-borne parasitic
disease called Leishmaniasis .
• It is spread by the bite of sandflies of the genus
Phlebotomus in the Old World, and of the genus
Lutzomyia in the New World.
• Leishmaniasis is the second-largest parasitic killer in
the world (after malaria) and is endemic in many
parts of Africa, Asia and South America.

3. HISTORY
• 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“.

4. CLASSIFICATION
• Kingdom
• Subkingdom
• Phylum
• Subphylum
• Class
• Order
• Genus
• Species
Protista
Sarcomastigophora
Protozoa
Mastigophora
zoomastigophora
Kinetplastida
Leishmania
donovani, tropica, mexicana
, braziliensis, etc.

5. IMPORTANT SPECIES
• L. donovani
• L. tropica
• L. mexicana
• L. braziliensis
• L.major
• L.guyanensis
• L.lainsoni
• L.naiffi
• L.aethiopica, etc

6. HABITAT
(L.donovani)
 Are essentially the parasites of visceral organs.
 Promastigote forms found in sand fly and in culture.
 Amastigote forms found in man in
reticuloendothelial cells of
spleen,
bone marrow,
liver,
intestinal mucosa,
mesentric lymph node.

7. L.donovani L. tropica L.mexicana L. braziliensis
Parasites of Visceral
organs
Skin Skin Skin and mucus
membrane of
nose and
buccal cavity
Amastigote
form found in
Human
Reticuloendothelial
cells of
•spleen,
• bone marrow ,
• liver
•intestinal
mucosa
Human
•Reticuloendothelial
cells of skin
Human
•Reticuloendothelial
cells of skin
Human
•Macrophage of skin
•Mucous membrane
of nose and buccal
cavity
Promastigote
form found in
Sand fly and
culture
Sand fly and
culture
Sand fly and
culture
Sand fly and
culture
HABITAT OF OTHER SPECIES

8. MORPHOLOGY
(same in all species)
• The parasite exists in
2 forms;-
1. Amastigotes –
aflagellar stage
2. Promastigotes-
flagellar stage

9. Morphological Differences
Amastigotes
• Aflagellar stage
• Occurs in the vertebrate host
• divides by binary fission at 37oC.
• There are round or oval ;2-4µm along longitudinal
axis.
• Nucleus relatively larger and situated centrally.
• Kinetoplast situated right angle to nucleus.
Promastigotes
• Flagellar stage
• Occurs in the sand fly
• 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.

10. LIFE CYCLE (L.donovani)

11. Life cycle of other species of Leishmania are similar to
L.donovani except that
In L.tropica
• amastigotes reside in the large mononuclear cells
of the skin
In L.mexicana
• Amastigotes found in reticuloendothelial cells
and lymphatic tissues of skin
In L.braziliensis
• amastigotes are found in reticuloendothelial cells
and lymphatic tissues of skin and mucus
membrane

12. MODE OFTRAMSMISSION
(L.donovani)
1. Mainly by the bite of sand fly (vector) Phlebotomus
argentipus
2. Les frequently by
• blood transfusion,
• congenital infection,
• accidental inoculation of cultured promastigotes in the lab.
workers, and
• sexual intercourse.
 Males are affected more (due to increased exposure to sand
flies through the occupation and leisure activities).

13. RESERVOIR
(L.donovani)
• Human:- in Indian subcontinent
• Rodents:- in Africa
• Foxes:- in Brazil and Central Asia
• Dogs :- In Mediterranean and China

14. L.donovani L.tropica L.mexicana L.braziliensis
Reservoir Man, rodents,
foxes, dogs
Man,
Dog
Sloth, ant
eater, rat, dog
Sloth, ant
eater, rat, dog
Vector Sand fly
Phlebotomus
argentipus
Sand fly
Phlebotomus
argentipus
Sand fly
Lutzomyia spp.,
Sand fly
Lutzomyia spp.,
Mode of
transmission
•Bite of sand
fly
•blood transfusion
•Congenital
infection
•sexual intercourse
Bite of sand fly •Bite of sand
fly,
•Bite of ticks ,
•autoinfection
•Bite of sand
fly,
•Bite of ticks ,
•autoinfection
Individual at
risk
Males are
affected more
Adolescents and
young adults
Persons working
at the edge of
forest and in the
people staying in
rural areas.
Persons working
at the edge of
forest and in the
people staying in
rural areas.
Reservoir, vector and transmission of other species

15. VECTOR
(Sand fly)
• Phlebotomas • Lutzomyia

16. CLINICAL MANIFESTATIONS
1. Pyrexia
2. Spleen enlargement
3. Lymphadenopathy
4. Darkening of the skin (KALA AZAR, MEANING “BLACK FEVER” IN HINDI, BECAUSE OF ITS
TENDENCY TO DISCOLOR ITS VICTIM’S COMPLEXION DURING ADVANCED STAGES)
5. Others:- kala-azar with HIV co-infection
Post kala-azar dermal leishmaniasis(PKDL)
 Complications:- pneumonia, TB, dysentery, uncontrolled haemorrhage
 Prognosis:- With an early treatment, cure rate >90%
If not treated, death occurs within 2 years.

17. CLINICAL MANIFESTATIONS OTHER SPECIES
L.tropica
• Oriental sore
• Acute necrotizing lesion
• scar
L.mexicana
• Chiclero ulcer
• Indolent nodular lesion
L.braziliensis
• Espundia
• Uta
• Pian bois

18. TYPES OF
LEISHMANIASIS
Leishmaniasis is divided into clinical syndromes
according to what part of the body is affected most.
Visceral Leishmaniasis(VL)
Cutaneous Leishmaniasis(CL)
Mucocutaneous leishmaniasis(MCL)

19. Continued....
1. Visceral Leishmaniasis (VL)
or Kala-azar
 caused by L.donovani
 part of the body affected most is
internal organs
Spleenomegaly

20. Continued....
2. Cutaneous
Leishmaniasis(CL)
( most common type)
a) Old world CL:- caused by
L.tropica, L. aethiopica
b) New world CL:- caused by
L.mexicana, L.braziliensis, L.g
uyanensis
c) Dermal leishmanoid or Post
kala-azar dermal
leishmaniasis(PKDL):- caused
by L.donovani
 Part of the body most affected
is skin

21. ....continued
3. Mucocutaneous
leishmaniasis(MCL)
 Caused by L. braziliensis
and occasionally by
L.panamensis
 Part of the body affected
most is skin and mucous
membrane of nose and
pharynx

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

23. LABORATORY DIAGNOSIS
Direct Evidences
Peripheral blood by thick
film
method.(Amastigote
form)
Blood culture in N.N.N.
Medium. (Promastigote
form)
Biopsy material obtained by
lymph node
puncture, sternal or iliac
crest puncture(marrow)
and spleen puncture(spleen
pulp) only for L. donovani
Indirect
evidences
Blood count
Serum Tests
Other
methods
Animal
inoculation
Leishmanin or
Montenegro
Test
Adler’s test

24. Direct Evidences (contd......)
1. Peripheral blood by thick
film method.(Amastigote
form)
Amastigotes in a macrophage

25. Direct Evidences (contd......)
2. Blood culture in N.N.N.
Medium. (Promastigote
form)
Promastigote from culture in NNN medium

26. Direct Evidences (....contd)
3. Biopsy material obtained
by
• lymph node puncture,
• sternal or iliac crest
puncture(marrow) and
• spleen puncture(spleen
pulp)
Amastigote form in a stained smear
Promastigote in culture in NNN medium
Amastigotes of L. donovani.
Splenic aspirate.

27. Indirect evidences
1. Blood count:-
• Leucopenia (progressive)
• Anaemia (raised ESR)
2. Serum Tests
• Aldehyde test- positive after 3
months.
• Antimony test- less reliable. Not
used now.
• Complement fixation test with
W.K.K. antigen. Not used now.
• Demonstration of antibodies
(ELISA, DAT, IHA, IFA with specific
antigen etc.)
• Molecular diagnosis:- DNA
Probes, PCR, etc.

28. Other methods
• Animal inoculation Wherever in vitro facilities
are not there, the material from patients can be injected
intraperitoneally in hamster or mice and the parasite is recovered
from the animal. In positive cases, the amastigotes can be
demonstrated in the stained impression smears of spleen from
animals.
• Leishmaninor Montenegro Test
It is a delayed hypersensitivity test. 0.2 ml of leishmania antigen
is injected intradermally. The test is read after 48-72 hrs. Positive
result is indicated by an induration of 5mm or more. In kala-azar
(visceral leishmaniasis), this test is negative
• Adler’s test:- It is a serological method. The
development of promastigote forms of Leishmania in Locke’s serum
agar can be inhibited by a immune serum specific to
L.donovani, L.tropica and L.braziliensis.

29. EPIDEMIOLOGY
• Found in more than 88 countries.
• Found on every continent except Australia and Antarctica.
• For cutaneous leishmaniasis, number of cases range from 0.7 million to 1.2 million .
• For visceral leishmaniasis, number of cases range from 0.2 million to 0.4 million.
• Annual incidence of disease= 600,000 cases per year.
• People infected worldwide=12 million.
• People at risk=350 million.

30. GEOGRAPHICAL DISTRIBUTIONS
• Present worldwide.
• 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, )

31. Current Geographic Distribution of
Leishmaniasis (....contd)

32. Leishmaniasis in Nepal
• Visceral leishmaniasis (kala azar) is common in the Terai region.
• The first confirmed case of VL was recorded in 1980.
• A total of 25890 cases with 599 deaths were reported during 1980-2006.
• During 2003, highest incidence (per 100,000) was in Mahottari district (184), followed by
Sarlahi (100) and Sunsari (96).
• Highest case fatality rate (CFR) was in Dhanusha (2.9%) followed by Bara (2.4%) and Saptari
(2.0%).
• Cutaneous leishmaniasis is rare in Nepal.
• First case of cutaneous leishmaniasis was reported in the year 2006 in Nepal.

33. Leishmaniasis in Nepal
(...contd.)

34. 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.
Education in the
community
About the causes and modes of
transmission of leishmaniasis.
Prevention of
exposure to sand fly
using insect repellent, bed nets and window
mess as needed.
PREVENTION AND
CONTROL
PREVENTION AND CONTROL
There are No Vaccines to prevent leishmaniasis.

35. PREVENTION AND CONTROL
(.....contd.)

36. TREATMENT
Drugs
Sodium
stibogluconate
solution
Inhibits glycolytic enzymes and fatty acid
oxidation
Amphotericin
B
Binds with ergosterol leading to the altered
permeability to cations, water, glucose and affect
membrane-bound enzymes.
Pentamidine Inhibits DHFR and interferes with aerobic glycolysis
in protozoa, also inhibits protein synthesis
Miltefosine Effects cell-signaling pathways and synthesis of the
cell-membrane
Interferon
macrophage activation

37. Specific therapy
supplemented with
treatment of secondary
microbial infections
high-calorie-high protein
diet
Blood transfusion in
severe anaemia
TREATMENT (....contd)

38. REFERENCES
• www.who.int
• www.cdc.gov
• www.Leishinfonet.com
• Chatterjee KD,(2009), Parasitology protozoology and
helminthology, 13th edition, CBS publishers and
distributers pvt. Ltd. New Delhi, India Page no.64-89
• Parija S.C., (2004), Textbook of Medical Parasitology, 2nd
edition, All India publishers and Distributers. Page No.81-
103

39. THANK YOU