2. At the end of this unit, the student
is able to:
Classify the Protozoans
Describe the morphology of each protozoa
Explain the pathophysiology, life cycle, infective stages,
modes of transmission, epidemiology, prevention and
control
Describe the diagnostic features of each parasite.
Enumerate the different specimens used for identification
Identify correctly the diagnostic features of each parasite.
3. Perform the laboratory tests
Discuss specimen collection,transport, processing,
preservation and disposal
4. General Characteristics
They are single-celled organisms which are generally
classified according to their organelles of locomotion.
Cilia, flagella & pseudopodia
Considered as the simplest forms of animals
12. Kingdom Protista
Subkingdom Protozoa
automonous unicellular eucaryotic organisms
possessing various degrees of cellular
specialization and some type of motility
Organelles specialize in nutrient storage,
excretion, digestion, motility
Phylum = based upon motility
Classification of Protozoa and Descriptions
13. Size 2 - 100 micrometers
Parasitic protozoa are most facultative anaerobes;
Mostly heterotrophic, chemoorganotrophs
Nutrients assimilated via phagocytosis, pinocytosis, diffusion
Digestion may be both extracellular and intracellular
Two life stages
Trophozoiteactive pathogenic vegetative stage
Cyst latent survival form
Sites of pathogenesis
Intestinal, Urogenital, Blood and Tissue
Pathogenic Protozoa - Characteristics
14. Phylum Sarcodina
Motility via Pseudopoda
Extensions of the cell membrane into which the
cytoplasm flows
Cyclosis
No cell wall; thus, no uniform shape
Shape changes with movement
Reproduce asexually by mitosis; sexually by meiosis
Trophozoite
Motile vegetative stage
Cyst
Latent survival stage
Protozoa - Amoeba
15. Phylum Ciliata
Motility via cilia
Cilia surround the cell; their co-ordinated movement
Uses energy from the cell membrane
Synchronized ciliary movement
Two nuclei per cell
Small micronucleus governs sexually reproduction
Large macronucleus governs metabolism and
growth
Both nuclei divide during asexual mitosis
Intracellular organelles
Function in digestion and excretion
Only one ciliate pathogen affects humans
Protozoa - Ciliates
16. Phylum Mastigophora
Motility via flagella
One or more whip-like filaments move in counter-
clockwise fashion creating rapid movement
A flagellum is a complex organelle composed of
many smaller tubules
Flagella attach to the cell membrane and derive
energy from movement from this membrane
Most numerous of the protozoan types
Several are pathogens of humans
All reproduce asexually; some reproduce sexually
Protozoa - Flagellates
17. Phylum Sporozoa
No established means of movement
Thus, not motile
All are intracellular parasites in a variety of hosts
Several parasitic species affect humans
Most are in the Class Coccidia
All lack intracellular organelles
All have three things in common
No motility
Sexual and Asexual mode of Reproduction
Intracellular parasites
Protozoa - Sporozoans
21. Intestinal and Luminal Protozoa
Constantly changing shapes, move by
ending out fingerlike extensions of their cell
membranes called pseudopods or “false-
feet” projections
the name comes from the Greek word for
“change” is an example of a sarcodine,
found in fresh water or salt water
22. six species have been established as parasites of man:
Entamoeba histolytica
Entamoeba coli
Entamoeba gingivalis
Dientamoeba fragilis
Endolimax nana
Iodamoeba butschlii
23. Intestinal and Luminal Protozoa
Stages of Development
Cyst – infective stage
Trophozoite – vegetative stage
24. General Statements:
All amoebas are capable of producing cyst and
trophozoite except for Entamoeba gingivalis
and Dientamoeba fragilis.
Found in the colon except Entamoeba
gingivalis which is found in the oral cavity
All are commensals except Entamoeba
histolytica.
25. Entamoeba histolytica
A) Trophozoite Stage (I & H preparation)
shape: irregular
shape: 10– 60 micra
structures:
- cytoplasm is grayish violet with a clear
demarcation between the ectoplasm
and endoplasm
31. Entamoeba histolytica
B. Cystic Stage
the number of nuclei range from 1-4,
rarely more, with a centrally located
karyosome
in the younger cyst, the chromatoidal
bars with rounded ends and glycogen
mass may be present
39. Entamoeba coli
A. Trophozoite Stage (I & H
preparation)
shape: condensed, thickened,
rounded mass
size: 15 – 50 micra
40. Entamoeba coli
A. Trophozoite Stage (I & H preparation)
structures:
cytoplasm is grayish violet; there is no clear
demarcation between the ectoplasm and
endoplasm
the endoplasm is highly vacuolated containing
bacteria
the nucleus is spherical with thick nuclear
membrane lined with coarse, irregular chromatin
granules or plaques; the karyosome is moderately
large and eccentrically located
44. Entamoeba coli
B. Cystic Stage
structures:
smooth, definite, thick cystic wall
number of nuclei range from 1 – 8 rarely
more with an eccentric karyosome
in younger cysts, chromatoidal bars with
splintered ends and glycogen mass
47. Endolimax nana
A.Trophozoite Stage (I & H preparation)
structures:
cytoplasm is grayish-violet, vacuolated
which may contain bacteria
there is small, spherical, single nucleus
with a large irregular, central or eccentric
karyosome
50. Endolimax nana
B. Cystic Stage
structures:
smooth, definite cystic wall
number of nuclei ranges from 1-4
I & H preparation
cytoplasm is grayish, granular
nuclei are visible as darkly stained dots
chromatoidal bodies occasionally seen as
deeply stained, small, slightly curved rods
51.
52.
53. Entamoeba gingivalis
A.Trophozoite Stage (I & H preparation)
shape: irregular
shape: 5 – 35 micra
structures:
clear demarcation between the clear
ectoplasm and granular endoplasm
54. Entamoeba gingivalis
endoplasm contains food vacuoles with
bacteria and rarely rbc
possesses a single nucleus which is
spherical in shape, karyosome is near the
center
have multiple pseudopodia with
progressive directional movement similar
to E. histolytica
57. A.Trophozoite Stage (I & H preparation)
structures:
cytoplasm is granular with vacuoles
containing bacteria
nuclei, commonly 2 in number, with
karyosome consisting of 4-8 chromatin
granules
Dientamoeba fragilis
60. Iodamoeba buetschlii
A.Trophozoite Stage (I & H preparation)
structures:
granular, vacuolated cytoplasm and
vacuoles may contain bacteria and yeast
cells
single, spherical nucleus with a large
central or eccentric karyosome
surrounded by an unstained halo
63. Iodamoeba buetschlii
B. Cystic Stage
structures:
smooth, definite cystic wall
have a single nucleus, rarely with 2
nuclei
large glycogen vacuole
64. Iodamoeba buetschlii
B. Cystic Stage
I & H preparation
violet-gray granular cytoplasm
nucleus is visible
large glycogen vacuole is unstained
chromatoidal bodies are usually
absent; if present, they are seen as
deeply stained small rods
68. A) Trophozoite Stage (I & H preparation)
endoplasm is briefly granular with
ingested rbc which are bluish black in
color
single, spherical nucleus; nucleus
membrane is lined by fine, regularly
arranged chromatin granules;
karyosome is relatively small and
centrally located
70. Amebiasis( Amebic dysentery)
- colitis with diarrhea(somtimes bloody) accompanied by abdominal pain
and cramping: numerous bloody stools per day
extraintestinal amebiasis a complication of intestinal amebiasis in
which the trophozoites enter the blood and are carried
to other organs; most often the liver
these patients have fever, leukocytosis, rigors
Parasite : Entamoeba histolytica
Trophozoite : sarcodine protozoa which slowly move among the crypts
of the large intestine and are shed into the feces
Cyst : latent survival stage which is significant in transmission;
spherical containing four characteristic nuclei; infective stage
Pathogenesis the trophozoites bind to colonic epithelial cells and secrete a
cytotoxin which alters cell membrane permeability causing the cells to take in
calcium and lyse; necrosis and inflammation also accompanies the lysis of
neutrophils, lymphocytes and monocytes
Pathogenic Protozoa - Entamoeba histolytica
71. Diagnosis microscopic observation of cyst in the feces
the trophozoite is seen occasionally
multiple concentrated stools specimens may be required since cysts
are distributed randomly
pathogenic amoeba must be distinguished from commensal amoeba
new test are designed to detect fecal antigen and trophozoite DNA
extraintestinal complications can be confirmed via biopsy or
serological tests for antibody
Epidemiology
reservior is infected humans, both asymptomatic and symptomatic
from 10 - 50 % of world population is infected
prevalence of infection in the U.S. is 1 - 2 %
asymptomatic individuals are chronic carriers
person -to - person, indirect, fecal-oral mode of transmission
food, water, fomites
fecal comtamination of fresh vegetables, water
flies and cockroaches also transmit the cysts mostly to food and
fomites
Entamoeba histolytica
72. Disease : Meningoencephalitis
destruction of the brain tissue causeing symptoms of
frontal headache, sore throat, fever, stiff neck, blocked nose
with alter senses of taste and smell, and Kernig’s sign(a sign
of meningitis in which the patient cannot flex the leg)
cerebrospinal fluid is purulent and may contain
erythrocytes
leads to rapid death in 4 - 5 days
Acanthomoeba can also enter the eye and cause keratitis
and corneal ulcers
Parasite : Naegleria fowleri or Acanthamoeba spp.
trophozoite is a free living amoeba found in soil and water
cyst
Naegleria fowleri/ and Acanthamoeba
73. Pathogenesis most infections occur when trophozoites in
water enter the nasal passages when people
swim; they then invade the nasal mucosa and extend into
the brain
Diagnosis:
trophozoites ( in wet mounts or stained smears) in
nasal discharge, cerebrospinal fluid, or corneal scrapings
Epidemiology - this organism is an environmental opportunist
acquired via contact with water, soil , or dust
74. major cause of a disease called PAM
has 2 long flagella at one end
most cases are contracted in lakes and
swimming pools
probably the flagellated trophozoites are
forced deep into the nasal passages
when the victim dives in water
found in USA, Czechoslovakia, Mexico,
Africa, New Zealand, Australia
77. cause chronic infection of the skinor CNS in
immunocompromised persons
has small spiky acanthopodia
causes keratitis
GranulomatousAmoebic Encephalitis
78.
79.
80. Naegleria Acanthamoeba
Trophozoite with
broad pseudopods
Actively motile
Forms the flagellate
stage
Single-walled cyst
Does not encyst in
tissues
Trophozoite with
filamentous pseudopods
Sluggishly motile
Does not form flagellate
stage
Double-walled cyst
May encyst in tissues
81.
82. Prevention and Control
Avoid swimming or jumping into bodies of warm
fresh water
Avoid swimming in thermally polluted water (water
around power plants)
Do not swim in areas posted as "no swimming."
Hold the nose shut or use nose clips when jumping
or diving into bodies of fresh water.
84. Balantidiasis : a dysentery (watery stools with blood and pus)
accompanied by nausea, anorexia, tenesmus, and
abdominal pain and tenderness
Parasite : Balantidium coli
Trophozoite ,an actively motile ciliate; highly specialized for
reproduction and food intake (cytostome)
Cyst, a latent survival stage is significant in transmission;
infective stage with one large nucleus
Pathogenic Protozoa - Balantidium coli
85. Pathogenesis : ulceration of the intestinal
mucosa especially in the large intestine sometimes
compounded by bacterial infection
no extraintestinal invasion as seen in amebiasis
Epidemiology : reservoir is swine and humans
fecal-oral transmission involving water and food
Diagnosis : microscopic observation of cysts in the feces
this trophozoite is very large and often seen also
93. Giardiasis : mild diarrhea to severe malabsorption syndrome;
sudden onset of watery diarrhea, often foul-
smelling, with abdominal cramps, flatulence, and
stearorrhea. Blood and pus are rarely present.
Parasite : Giardia lamblia
Trophozoite - flagellate protozoan( 10 x 10 um) having two
large nuclei, a large sucking disc, and many
flagella; face - like appearance
Cyst - slightly smaller the trophozoite with four nuclei and
parabasal body
Pathogenic Protozoa - Giardia lamblia
94. Pathogenesis : gastric acid stimulates excystation and releases
trophozoite into small intestine where it attaches via
the sucking disc to the intestinal villi; the alteration of the villi
and inflammation of the mucous causes maladsorption, but
not obvious tissue necrosis; spontaneous recovery occurs in
10 -14 days, but relapse may occur; chronic infection is
especially a problem in patients with IgA deficiency and
diverticula
95. Diagnosis : cyts and trophozoites in the feces with the onset of
symptoms; cyts occur in”showers” and are not
present every day, so stoo should be examined
every three days
in the absence of observable cysts, new tests for fecal antigen are now
available
Epidemiology : sylvatic and domestic reservoirs, both human
and animals(mostly those around lakes
and streams;
fecal - oral transmission via contaminated water is most
common mode of transmission; in U.S. domestic setting,
fecal- oral fomites transmission is very common in day care
settings; also uncooked contaminated vegetable and fruits
may serve as a source of the cysts
cyst are resistant to traditional chlorination methods
other than day-care centers, most recent outbreaks have
involved contaminated water from reservoirs
Pathogenic Protozoa - Giardia lamblia
99. Incubation Period is typically 5 to 28 days
Trichomonas vaginalis is pathogenic in the
genitourinary tract
In women, it lives in the vagina and the
Skene's glands (of the urethra)
In men, it lives in the urethra
Multiplies when vaginal conditions become
more basic than usual (normal pH is 3.8 to
4.2)
No known cystic form
May survive in a host for 2+ years
100. Vaginitis and urethritis : itching, burning, and painful
urination sometime accompanied by scant watery
vaginal discharge
Parasite : Trichomomas vaginalis
only a flagellate trophozoite with four flagella and
undulating membrane
this flagellate has not cyst stage
Pathogenesis : extensive inflammation and erosion of the
vaginal or urethral epithelium causing itching, burning,
and painful urination; also sometimes a scanty watery
vaginal discharge
Pathogenic Protozoa - Trichomonas vaginalis
101. Epidemiology : human reservoir with many asymptomatic
carriers especially in males- females may also be
asymtomatic
trophozoite is sexually transmitted
Diagnosis : microscope examination of vaginal or urethral
discharge
stained smear show trophozoites
also parasite is detected in fluorescent antibody stains and
nucleic acid probes
106. Cryptosporidosis enterocolitis characterized by water
diarrhea without blood - self limiting in immunocompetent
people
Parasite : Cryptosporidium parvum
Sporozoan(coccidian) parasite exhibits both
asexual(schizogony) and sexual(gametogony) in the brush
border of the intestinal epithelium
Oocyts are released from the cells and transmitted
Pathogenesis : In immunocompromised patients, an
unremitting enterocolitis with as many as 50 water stools per
day caused by the intracellular multiplication of the parasite
Pathogenic Protozoa - Cryptosporidium
parvum
107. Epidemiology : reservoir is a variety of mammals, fish, reptiles
this host seed the environment especially water with oocyts
a-p, indirect, fecal-oral, contaminated water/fecal droplets
p-p, indirect, fecal-oral/oral-anal - fomite/direct contact
high risk groups = homosexuals, day care children/adults,
animal handlers
Diagnosis : oocysts in the feces: concentrated and stained
also assay for fecal antigen
110. Cyclosporiasis -water diarrhea accompanied by nausea,anorexia,
abdominal cramping: sometime bloating
and flatulence
Parasite Cyclospora cayetanensis
a sporozoan(coccidian) parasite of the small intestine
asexual and sexual cycle similar to Cryptosporidium but
oocysts are larger
Pathogenesis inflammatory changes in the jejenum
resulting from the intracellular multiplication of the parasite =
villous atrophy
Pathogenic Protozoan -Cyclospora
cayetanensis
111. Epidemiology : reservoir is a variety of mammals, birds, reptile
source to humans is fecally contaminated water and some
fresh fruits like strawberries
Diagnosis : detection of oocysts in the stool: concentrated
and stained by a variety of methods
including immunofluorescence
121. Species Stages found in the circulating blood
P. vivax All stages. Wide range of stages may be seen
on given film
P. malariae All stages. Wide variety of stages usually not
seen. Relatively few rings, gametocytes
generally present
P. ovale All stages
P.
falciparum
Rings and or gametocytes. Other stages develop in
blood vessels of internal organs but are not seen in
peripheral blood except in severe infections
122. Trophozoite or ring forms
young form is globose in shape with a
central vacuole, a red chromatin mass
and a blue cytoplasm
- in stained smear, they appear signet
rings
123. b) Growing form
- single chromatin
mass with a more
abundant cytoplasm
- cytoplasm may
appear compact or
irregular (ameboid)
c) Mature form
- single
chromatin mass but
with an increase
amount of cytoplasm
that partially fills the
erythrocyte
124. Early trophozoites have
the characteristic
signet ring shape.
Also, unique to P.
falciparum is the
presence of multiple
trophozoites in one
cell.
126. The gametocytes of P.
falciparum have a
crescent or banana
shape.
127. Red blood cells
infected by P. vivax are
often larger than
uninfected red blood
cells.
They are
approximately 1.5
times the size of a
normal cell.
129. A schizont showing the
large number of
merozoites typical of
this species (16-24).
Also note the larger
size compared to a
normal red blood cell.
130. Characteristic
trophozoites of P.
malariae showing the
ring shape and the
tendency of infected
cells to be of normal or
smaller size (arrows).
131. A schizont containing
merozoites (6 to 12)
giving a coarse
granular appearance.
132. Species rbc stage Size of rbc Schauffner’s
stippling
P. vivax Young rbc enlarged +
P. malariae Mature rbc normal -
Ziemann’s
dots
P. ovale Young rbc enlarged +
P. falciparum rbc of all
stages
Normal/
Multiple
infection
_
Maurer’s dots
133. A red blood cell
showing the
Schauffner's dots
characteristic of cells
infected by
Plasmodium vivax and
Plasmodium ovale.
Schauffner’s dots
134. Species Cytoplasm Pigment No. of
merozoites
Gametocytes
P. vivax Irregular,
ameboid in
trophozoite,
has spread
out
appearance
Golden
brown,
incons-
picuous
12-24
Average is
16
rounded
135. Species Cytoplasm Pigment No. of
merozoites
Gametocytes
P.
malariae
Rounded,
compact
trophozoite
with dense
cytoplasm/
band form
troph are
rarely seen
Dark
brown,
cons-
picuous
6-12
Average is 8,
“rosette”
schizonts are
sometimes
seen
rounded
136. Species Cytoplasm Pigment No. of
merozoites
Gametocytes
P. ovale Rounded,
compact
trophozoite
with dense
cytoplasm/
band form
troph are
rarely seen
Dark
brown,
cons-
picuous
6-12
Average is 8,
“rosette”
schizonts are
sometimes
seen
rounded
137. Species Cytoplasm Pigment No. of
merozoites
Gametocytes
P.
falciparum
Young rings
are small,
delicate,
often with
double
chromatin
mass
Black
coarse and
cons-
picuous in
gametocyte
6-32
Average is
20-24
Crescent,
sausage-
elongate
shape
139. Toxoplasmosis : infectious mononucleosis -like symptoms
of fever, chills, headache, myalgia, lymphadenitis,
and fatigue; chronic form = hepatitis,
encephalomyelitis, mycocarditis
Parasite : Toxoplasma gondii
intracellular coccidian(sporozoan) parasite infecting various
tissues(systemic) but confined to intestines in felines
infected tissues release pseudocysts containing bradyozoites
feline intestines release oocyts containing tachyzoites
Pathogenesis : cellular death due to intracellular muliplication
of trophozoites especially severe in fetal and cerebral
tissues
Pathogenic Protozoa - Toxoplasma gondii
140. Epidemiology : reservoir is a variety of mammals and birds
including humans
fecal-oral transmission of oocyst from felines
common source transmission of pseudocyts in poorly cooked meat
esp. beef
Diagnosis : serological detection of antibody: Elisa test for
IgM antibodies is most reliable
Risk Groups : Pregnant females and immunocompromised
141.
142.
143. Enteroepithelial cycle
asexual schizogony
Sexual gametogony
*immature oocyst passed in the cat’s feces
Immature oocyst mature to the infective stage
2 sporocysts with 4 sporozoites each (2-21 days)
144. Ingestion of inadequately cooked meat, esp
lamb or pork
Ingestion of infective oocysts from material
contaminated by cat feces
Drinking contaminated water or unpasturized
goat’s milk
Organ transplantation
Blood transfusion
Transplacental
145. When mature oocyst is ingested, sporozoites
are released forming trophozoites
*tachyzoites- actively growing trop
*bradyzoites- latent or slow growing
trophozoites
146. Active infection (all nucleated cells)
fever
lymphadenopathy
Congenital
depends on the age of gestation when the
infection is acquired
147. 1st half pregnancy
- intrauterine death
- microcephaly
- hydrocephaly with intracranial calcification
148. 2nd half of pregnancy
-usually assymptomatic at birth though fever,
hepatosplenomegaly and jaundice may
appear
-choriorenitis, psychomotor retardation and
convulsive disorders may appear months or
years later
150. Examination of tissues, blood, and body fluids
- Demonstration of tachyzoites or tissue cysts
- Animal inoculation to uninfected mice
- PCR
- Sabin-Feldman dye test
- IFA
- EIA
152. Infection of rbc often producing febrile illness
Transmitted by ticks (Ixodes scapularis, Ixodes
pacificus)
Caused by Babesia microti
mulitiply in rbc by schizogony but do not produce
gametocytes
Appear as delicate ring forms that may easily
confused with malaria
161. Patients with spleen only 25% of RBCs could be parasitized
Patients withoutspleen higher parasitemia fever, muscle aches,
chills, fatigue, headache and loss of appetite Capillary microvascular stasis
RBC fragments Hemolytic anemia liver, spleenic, renal and
Central Nervous System involvement.
163. antimicrobial drugs such as clindamycin*
plus quinine or atovaquone* plus
azithromycin are often used.
Prevention/Control
- wearing appropriate light-colored clothing
-using tick repellent in areas where the diseases
are endemic
-if possible test blood to be transfused for possible presence
of Babesia species
166. Species Disease Portal of Entry and
Final Site
Vector
Trypanosoma cruzi
Trypanosoma brucei
gambiense
Trypanosoma brucei
rhodesiense
American
Trypanosomiasis or
Chagas’ Disease
Gambian or West
African Sleeping
Sickness
Rhodesian or East
African Sleeping
Sickness
Breaks in skin or intact
mucous membranes,
later any organs and
blood stream; Heart and
GIT in chronic form
Skin for both
Lymph nodes, blood,
and brain
Infected
Triatomine
bug
Infected
tse-tse flies
167. African Sleeping Sickness CNS infection progressing to
lethargy, tremors, meningoencephalitis, convulsions,
coma, and death
Parasites
Trypanosoma gambiense - West/Central Africa
Trypanosoma rhodesiense - East Africa
Pathogenesis - trypanomastigote multiplies in the blood,
lymph, and cerebrospinal fluid; deprives the brain of
amino acids
Pathogenic Protozoa - Trypanosoma brucei
168. Epidemiology : reservoir is a variety of mammals
and birds including humans
fecal-oral transmission of oocyst from felines
common source transmission of pseudocyts in poorly
cooked meat esp. beef
Diagnosis : serological detection of antibody:
Elisa test for IgM antibodies is most reliable
Risk Groups : Pregnant females
and immunocompromised
169. American Trypanosomiasis/Chagas Disease -systemic infection
beginning with fever, chills, malaise, myalgia, fatigue, and
chagoma; progressing to involve heart and brain
Parasite = Tryanosoma cruzi
flagellate tryanosome exhibiting both the intracellular
amastigote(leishmanial) form and the extracellular
trypanomastigote(trypanosmal) form
Pathogenesis - the intracellular amastigote multiplies in cells
and destroys the cells
Pathogenic Protozoa - Trypanosoma cruzi
170. Epidemiology- wild and domestic animal reservoirs
arthropod-borne via the cone-nosed (reduviid) bugs
which live in the cracks of domestic dwellings
Diagnosis : trypanosomes in the blood; amastigotes
in biopsy; also xenodiagnosis and gene probes
171.
172.
173. Local inflammation at the site of
inoculation.
CHAGOMA = reddish painful nodule
Trypanosmes may enter the conjunctiva
= edema of eyelid & conjunctiva =
ROMAÑA’S SIGN
174.
175.
176.
177. Winterbottom's sign
is the swelling of
lymph nodes
(lymphadenopathy)
along the back of the
neck, in the posterior
cervical chain of
lymph nodes, as
trypanosomes travel
in the lymphatic fluid
and cause
inflammation.
178. w/ CNS invasion = chronic disease known as sleeping sickness stage is
initiated
(Kerandel’s sign) = delayed sensation to pain indicative ofAfrican
trypanosomiasis
Untreated infection may lead to death
180. Species Disease Portal of Entry and
Final Site
Vector
Leishmania
donovani
Leishmania
tropica
Leishmania
brazilienses
Visceral Leishmanisis
or KALAAZAR
Cutaneous
Leishmaniasis
Mucocutaneous
Leishmaniasis
or ESPUNDIA
Skin/ Macrophages and
monocytes of spleen,
liver, bone marrow
Skin/ Macrophages of
the skin and mucosa
Infected
Phlebotomus
Fly
181. Leishmaniasis;Visceral : gradual onset of fever, chill, sweating,
diarrhea, anemia which progresses to enlargement of
liver and spleen with weight loss and emaciation: later
kidney damage and granulomatous skin lesion = also called
kala-azar
cutaneous form -ulcerative skin lesions which contain parasite:
become infected with secondary bacteria and scar
formation disfigures
Parasites : Leishmania donovani - visceral- amastigote stage
multiplies in visceral cells causing lysis
Leishmania tropica - cutanous: Leishmania braziliensis –
mucocutaneous
Pathogenesis - cells in infected visceral and cutaneous tissues
are destroyed by intracellular amastigote
multiplication
Pathogenic Protozaa - Leishmania
182. Epidemiology : animal reservoirs including dogs and cats
arthropod-borne via the bite of sandflies: the amastigote stage
becomes a motile promastigote in the sandfly gut
Diagnosis : amastigote is observed in tissue biopsy, body
fluid aspirates, and in the blood: also serology for antibody
presence
183. Species Amastigote Promastigote Epimastigote Trypomastigote
Leishmania
Animal Host
Vector
Macrophages
-
-
midgut and
pharynx of
sandfly
-
-
-
-
Trypanosoma
Animal Host
Vector
-
-
-
-
-
salivary gland and
gut of flies/
culture
Blood, lymph
nodes, brain, CSF
-
Trypanosoma cruzi
Animal Host
Vector
Intracellular,
esp. striated
and smooth
muscle, brain
Cell cultures
-
-
-
-
Intestine of vector
bugs
Blood and tissues
of mammals
Rectum of vector
bug/culture and
cell cultures
192. The current standard treatment for first stage
disease is:
Intravenous pentamidine (for T.b. gambiense);
or
Intravenous suramin (for T.b. rhodesiense)
Eflornithine
