HEMOFLAGELLATES - Geographical Distribution:

Asia Minor, Middle and South

TRYPANOMES
west asia, North Africa,
1. Trypanosoma brucei gambiense Mediterranean, Europe and
- Disease: West African sleeping Central America
sickness
- Vector: Phlebotomous specie
- Geographical Distribution: (sandfly)
Central and West Africa
2. Leishmania braziliensis
- Vector: Glossina specie (Tsetse
fly) - Disease: a. Espundia or
mucotaneous leishmaniasis
(MCL)
2. Trypanosoma brucei b. Chiclero’s ulcer or
rhodesiense New World Cutaneous
- Disease : East African sleeping leishmaniasis (NWCL)
sickness
- Geographical Distribution:
- Geographical Distribution: Central and South America
East Africa
3. Leishmania donovani
- Vector: Glossina specie (Tsetse - Disease: Kala azar or visceral
fly) leishmaniasis

- Geographic Distribution: India,

3. Trypanosoma cruzi China, Soviet Union,
- Disease: Chaga’s disease or Mediterranean, East & North
American trypanomiasis Africa, Caspian Littoral, Arab
Peninsula, Persian Gulf
- Geographical Distribution:
Central and South America - Vector: Phlebotomous specie
(sandfly)
- Vector: Tratoma or Reduviid
bugs (kissing bug or Assasin
STAGES OF DEVELOPMENT OF
bug)
HEMOFLAGELLATES
1. Amastigote or leishmania form –
LEISHMANIA
ovoidal without free flagellum
1. Leishmania tropica
- Disease: Oriental sore or Old 2. Promastigote or leptomonas form
World Cutaneous – elongated and spindle-shaped
Leishmaniasis (OWCL) with pointed end and a free
 flagellum that arise from the
kinetoplast at the anterior end PROMASTIGOTE

3. Epimastigote or Crithidia –
elongated and spindle-shaped with
free flagellum continues from the
anterior end backward along the
margin of the undulating
membrane and the ends of the
kintoplast which is situated
anterior to the nucleus

4. Trypomastigote or Trypanosoma- EPIMASTIGOTE

morphologically similar to
epimastigote except that the
flagellum on the margin of the
undulating membrane ends at the
kinetoplast which is situated
anterior to the nucleus.

- In Trypanosoma brucei group,

only the epimastigote and
trypomastigote forms are
TRYPOMASTIGOTE
present,
- In Trypanosoma cruzi, all
stages of development are
present.

HEMOFLAGELLATES

AMASTIGOTE
TRYPANOSOMES
- For Trypanosoma brucei group,
the transitional forms in
invertebrates are epimastigote
while in the blood of
mammalian host
trypomastigotes are produced.

- In case of T. cruzi, it has

trypomastigotes in the gut of
 the invertebrate host and in Trypanosoma cruzi: LIFE
the blood of mammalian host, CYCLE
amastigotes intracellularly in
the mammalian host and
epimastigote in the midgut of
the invertebrate host.

TRYPANOSOMES: MORPHOLOGY
- Trypanosomes are minute,
actively motile, fusiform,
flattened from side to side
measuring 14 – 33 microns in
length and 1.5 – 3.5 microns in
breadth.

- A large oval nucleus with a

central karyosome is centrally
located. The flagellum along
the margin of the undulating
membrane arises from the
posteriorly located kinetoplast
and continues anteriorly as the Trypanosoma brucei group:
PATHOLOGY
free flagellum.
- In humans the disease varies in
severity from a mild type, with
African Trypanosomes: LIFECYCLE
few trypanosomes in the blood
to a severe fulminant type.

- In the typical case the disease

progresses from the acute
stage, with trypanosomes
multiplying in the blood and
lymphatics during the 1st year
or the beginning of the 2nd
year and terminates during the
2nd or 3rd year.

- The fever and headache are

more pronounced, evidence of
nervous impairment includes
lack of interest and
disinclination to work,
avoidance of acquaintances,
 morose and melancholic Trypanosoma cruzi: PATHOLOGY
attitude, mental retardation,
- The disease manifest primarily
low and tremulous speech and
as chagoma, a slightly painful
altered reflexes.
nodule at the site of
inoculation and later by
- The terminal sleeping stage
metastatic lesions throughout
now develops and gradually
the body notably in the heart,
patient becomes more and
esophagus and lower intestine.
more difficult to rouse. Death
result either from the disease
- Signs and symptoms of heart
or from intercurrent infection,
failure, megaesophagus and
such as malaria, dysentery, and
megacolon eventually are
pneumonia.
observed when these organs
are involved.
TRYPANOSOMES: PATHOLOGY
TRYPANOSOMES: PATHOLOGY
AFRICAN SLEEPING SICKNESS Romaña sign
CHAGAS DISEASE

TSETSE FLY
CHAGOMA
 TRIATOMA BUG - For Chagas disease, Nifurtimox
and Bezuidazole are only
partially effective in acute
disease.

TRYPANOSOMES: EPIDEMIOLOGY,
PREVENTION AND CONTROL
- African trypanosomiasis is
endemic in are known as
“tsetse belt”, extending over a
TRYPANOSOMES: DIAGNOSIS third of Africa. Chagas disease
- Diagnosis of T. brucei group is is prevalent throughout Central
based on the presence of and South America.
trypanosomes in stained blood
preparation and lymph - Infection with T. brucei group
aspirates. can be prevented by reduction
of the pool of contact with
- For T. cruzi, a thick blood Tsetse fly through control
smear maybe examined for the measures (traps, screens,
presence of trypanosome. insecticides) and by reduction
Xenodiagnosis maybe of the pool of human infection
employed using laboratory by diagnosis and treatment.
reared bugs.
Prevention of Chagas disease is
- These bugs are allowed to feed based on vector control,
on patient’s suspected of being screening and sterilization of
infected and later examined transfusion blood and health
for the presence of T. cruzi. education.

LEISHMANIA
TRYPANOSOMES: TREATMENT - Leishmania are flagellates that
- For African sleeping sickness, occur as intracellular
Pentamidine and Suramin have amastigotes in vertebrate
been used although both drugs hosts and as flagellate
do not enter the CSF. promastigote in invertebrate
hosts.
- Melarsoprol has been used for MORPHOLOGY:
late stage of the disease with
CNS involvement. - Amastigotes are small, ovoid
measuring 2 – 3 microns and
living intracellularly in
 monocytes, PMN or lesions does not heel
endothelial cells. spontaneously.

- The nucleus is large while 2. Mucocutaneous leishmaniasis

axoneme arises from the - The initial lesion at the bite site
kinetoplast and extends to the is papule that later develop
anterior tips. into ulcer. Metastatic spread
may occur on the oronasal and
- Promastigotes have a single pharyngeal mucosa, causing
free flagellum arising from the highly disfiguring leprosy like
kinetoplast at the anterior end tissue destruction and swelling
measuring 15 – 20 microns. (Tapir nose).

3. Visceral leishmaniasis
LEISHMANIA: LIFE CYCLE
- The usual clinical manifestation
are fever, malaise, and weight
loss, loss of appetite, cough,
diarrhea, anemia, wasting, skin
darkening, splenomegaly,
hepatomegaly, and
lymphadenopathy.

- The phagocytosed parasites

are present only in small
numbers in the blood but they
are numerous in the
reticuloendothelial cells of the
spleen, liver, lymph nodes,
bone marrow, intestinal
mucosa, and other organs.

LEISHMANIA: DIAGNOSIS
- Smear of lesion can be stained
LEISHMANIA: PATHOLOGY
with Wright or Giemsa.
1. Cutaneous leishmaniasis Specimen can be cultured also
- There is ulceration in the skin, NNN (Nicole, Novy, Mc Neal).
which upon healing leaves an
ugly scar. Diffuse cutaneous - Montenegro skin test may also
leishmaniasis causes be used for diagnosis. Another
widespread thickening of the test is the formol-gel test
skin wherein the lesion making use of 0.1-ml serum
resembles those of and one drop of formalin and
lepromatous leprosy and these the positive result is gel
 formation. This will serve as
screening test.

LEISHMANIA: TREATMENT
- Primary drug treatment is
based on antimony
compounds, Pentavalent
antimonials, Sodium
atiboglucolate and N-methyl-
glucamine antimonate
(meglumine).

- Second line drugs include the

antimicrobial Amphotericin B,
Pentamidine (for Kalaazar),
Metronidazole and Nifurtimox.

LEISHMANIA: EPIDEMIOLOGY,
PREVENTION AND CONTROL
- Leishmaniasis occur in the
Southern regions of America,
the Mediterranean, East and
North Africa, Arabian
Peninsula, Persian Gulf, Indian
subcontinent, China and
Southern Soviet Union.

- Control measure include

vaccination, control of sandfly
vectors, protective measures
from sandflies, mechanical
destruction of animal reservoir
habitats and poisoning of
animals themselves.

- Yumiefd.