Malarial Parasite Flashcards
PLASMODIUM
● Normally transmitted by the bite of Plasmodium infected
female mosquito
Vertebrates: asexual or sexual
asexual cycle (Schizogony)
Invertebrate: asexual or sexual?
: sexual cylce (Sporogony)
Stage:
● Feeding or growing stages in the asexual cycle
● Lives within the tissue cells
- TROPHOZOITE
Stage:
Sporozoan body during schizogony
SCHIZONT
stage: ● Released from the infected cell
● Some will infect other tissue cells going back to the
trophozoite stage
● Others will be differentiated into male and female forms
(gametocytes)
- MEROZOITES/ LATE SEGMENTERS
IMMATURE SEXUAL FORM
. GAMETOCYTES -
stage:
● Fertilized ovum/ova before cell division
● Union of macrogamete and microgamete
- ZYGOTE
○ Female gametocyte
○ Produce a macrogamete
○ Mature only to be fit for fertilization
MACROGAMETOCYTES
○ Male gametocyte
○ Produce a group of microgametes
MICROGAMETOCYTES
Mature sexual form of plasmodium
- GAMETES
○ Female gametocyte
○ Produce a macrogamete
○ Mature only to be fit for fertilization
A. MICROGAMETOCYTES
○ Male gametocyte
○ Produce a group of microgametes
B. MICROGAMETOCYTES
Male sex cells in sporozoa
MICROGAMETES
○ Female sex cells in sporozoa
MACROGAMETES
stage:
● Encysted zygote
- OOCYST
stage:
● end product of sexual multiplication of malarial parasites in
mosquito
- SPOROZOITE
stage: ● one of a number of bodies in many sporozoa into which the
zygotes divide and from which sporozoites are formed
- SPOROBLAST
stage:
● the separated membrane that surrounds a sporoblast and
subsequently the group of sporozoites formed from this
sporoblast
- SPOROCYST
● Fertilized ovum/ova before cell division
● Union of macrogamete and microgamete
ZYGOTE
– rapidly multiplying stage in the development of the tissue phase of
certain organisms such as Toxoplasma gondii
Tachyzoites
P.vivax cause what disease?
Benign Tertian Malaria
Incubation Period of p.vivax
12-20 days
Incubation Period:PLASMODIUM OVALE
11-16 days
prepatent period of p.vivax
11-15 days
PLASMODIUM OVALE Has recently been shown by genetic methods to consist of two
species
1) Plasmodium ovale curtisi
(2) Plasmodium ovale wallikeri
Intermittent fever every 72 hours
PLASMODIUM MALARIAE
Prepatent period: PLASMODIUM OVALE
14-26 days
Intermittent fever every 48 hours
PLASMODIUM OVALE and p.vivax
The ____ can lead to severe disease and death due
to splenomegaly
vivax malaria
P.ova causes what disease
Ovale Tertian Malaria
Incubation Period: PLASMODIUM MALARIAE
18-40 days
Prepatent period:PLASMODIUM MALARIAE
3-4 weeks
p.mala cause what disease
Quartan Malaria
MALARIAL PAROXYSM
3 STAGES:Symptoms would usually diminish at this stage
SWEATING STAGE
Causative agent PLASMODIUM FALCIPARUM
Malignant Tertian Malaria
MALARIAL PAROXYSM
3 STAGES:
● There is a sudden feeling of cold or a feeling of inappropriate
convulsion
● characterized by mild shivering, violent teeth chattering
● Vomiting and febrile convulsions
- COLD STAGE
Intermittent fever every 36-48 hours
PLASMODIUM FALCIPARUM
incubation Period PLASMODIUM FALCIPARUM
8-15 days
Prepatent period: PLASMODIUM FALCIPARUM
11-14 days
MALARIAL PAROXYSM
3 STAGES: Rigors last for 14-60 minutes
COLD STAGE
MALARIAL PAROXYSM
3 STAGES:
● Characterized by very high temperature of 40-41C
. HOT STAGE OR FLUSH PHASE
ERYTHROCYTIC CYCLE: 48 hours
P. FALCIPARUM:
MALARIAL PAROXYSM
3 STAGES:
Manifests with headache
● palpitations , tachypnea, epigastric discomfort
● Because of the high temperature, thirst, nausea and vomiting
● Last for 2-6 hours
- HOT STAGE OR FLUSH PHASE
MALARIAL PAROXYSM
3 STAGES: Temperature lowers over the next 2 to 4 hours because of the
sweating
- SWEATING STAGE:
MALARIAL PAROXYSM
3 STAGES: In this stage, there is also convulsion and the patient can
become delirious because of the very high temperature and
the skin is usually flushed and very hot
HOT STAGE OR FLUSH PHASE
ERYTHROCYTIC CYCLE: paroxysms occur on alternate days hence causing Tertian
malaria
P. OVALE AND P VIVAX
MALARIAL PAROXYSM
3 STAGES: Total Duration: 8-12 hours
SWEATING STAGE:
ERYTHROCYTIC CYCLE: paroxysms 72 hours (on 1 and 4 days)
❖ Quartan malaria
PICTURE: DISSEMINATED INTRAVAS
P. MALARIAE:
DIAGNOSIS: ❖ In P. falciparum only the____can be found which would
usually be done 10 days after symptoms begin, gametocytes
may be found.
ring form ; THICK AND THIN BLOOD FILM EXAMINATION
s Disseminated Intravascular Coagulation
that can be seen in
P. falciparum
DIAGNOSIS: Malarial parasites: bright green and yellow under fluorescent
microscope
QUANTITATIVE BUFFY COAT (QBC)
DIAGNOSIS:
❖❖ Special capillary tube coated with Acridine orange
QUANTITATIVE BUFFY COAT (QBC)
DIAGNOSIS:❖ Giemsa and Wright’s stain
❖ Specimen collection which can be done anytime every 6-8
hrs is appropriate)
THICK AND THIN BLOOD FILM EXAMINATIO
DIAGNOSIS: ❖ Only used for screening and needs thick, thin films
QUANTITATIVE BUFFY COAT (QBC)
DIAGNOSIS:Antigen capture test
PARASIGHT F TEST
DIAGNOSIS: High sensitivity and good specificity
PARASIGHT F TEST
DIAGNOSIS: This is a dip stick test for simple and rapid diagnosis of P.
falciparum
PARASIGHT F TEST
DIAGNOSIS:
PARASIGHT F TEST antigen
Ag: trophozoite-derived histidine-rich protein II
(HRP-II)
TREATMENT To prevent establishment of the parasite in the liver
CAUSAL PROPHYLACTIC DRUGS
TREATMENT destroy the sexual form of parasite in the blood
GAMETOCYTOCIDAL DRUGS
MORPHOLOGY:
Ovoidal, pyriform or cresentic
TOXOPLASMA GONDII
TREATMENT attacks the parasite in red blood cells
BLOOD SCHIZONTICIDAL DRUGS
TREATMENT prevents the occurrence of the disease
HYPNOZOITICIDAL OR ANTI-RELAPSE
MODE OF TRANSMISSIONTOXOPLASMA GONDII
Ingestion of uncooked meat, fecal contamination, nasal route,
transplacental
Drug of choice for malaria
CHLOROQUINE
TREATMENT it inhibits the development of the oocysts in the gut of the
mosquitoes.
SPORONTICIDAL DRUGS:
MAIN USES OF ANTIMALARIAL DRUGS: MAIN USES OF ANTIMALARIAL DRUGS:
Curative-
MAIN USES OF ANTIMALARIAL DRUGS: prophylactic
Protective-
CHLOROQUINE combination
Pyrimethamine/sulfadoxine
So there is an exogenous asexual phase in the mosquito
called the
sporogony
MODE OF REPRODUCTION TOXOPLASMA GONDII
longitudinal binary fission
drug for severe falciparum malaria
Quinine or quinidine:
TOXOPLASMA GONdii HOST:
cats
OPPORTUNISTIC SPOROZOANS:
- Toxoplasma gondii
- Cryptosporidium specie
- Pneumocystis carinii
- Isospora belli
TOXOPLASMA GONDII DISEASE:
Toxoplasmosis
T,gon infective stage
oocyst
ONE OF THE MOST
COMMON HUMAN INFECTIONS THROUGHOUT THE WORLD
TOXOPLASMOSIS
IS A PROTOZOAN PARASITE THAT
INFECTS MOST SPECIES OF WARM BLOODED ANIMALS
INCLUDING MAN AND CAN CAUSE THE DISEASE
TOXOPLASMA GONDI
a high prevalence of infection in ___ has been related to a
prevalence for eating raw or undercooked meat
France; t,gondi
high prevalence in ____ has been related to the
frequency of stray cats in a climate favoring survival of
OOCYST and soil exposure
central America; t.gondii
TISSUE STAGES IN MAN of T.gondi; fast rapid, multiplication, acute phase
TACHYZOITEs
TISSUE STAGES IN MAN of T.gondi ; slow proliferation during this stage, chronic phase
BADYZOITES
TISSUE STAGES IN MAN of T.gondi; Female who first to acquire the infection
during pregnancy may transmit the
infection to embryo resulting in fetal
death, or mental retardation on newborn,
or blindness in later life
TACHYZOITES
TISSUE STAGES IN MAN of T.gondi ; Major cause of encephalitis in AIDS
patients
TACHYZOITES
congenital or acquires toxoplasmosis? Regional lymph node invasion
o Intracellular multiplication in various organ
ACQUIRED TOXOPLASMOSIS
TISSUE STAGES IN MAN of T.gondi Toxoplasma divide in tissues of man as
tachyzoites
Associated with RES, or endothelium of
the circulatory system
Serous fluids in body cavities
Necrosis of the invaded area
Pseudocysts (group of bradyzoites) are
also formed
TACHYZOITES
congenital or acquires toxoplasmosis? o Occurs in 1-2% per 1000 pregnancies
o Severe and fatal
CONGENITAL TOXOPLASMOSI
congenital or acquires toxoplasmosis? Hydrocephaly, choiretinitis, microcephaly,
psychomotor disturbances and convulsions
CONGENITAL TOXOPLASMOSIS
Appears after the infection and
regional lymph node invasion
Parasite is blood borne to
many organs where
intracellular multiplication
takes place
Acquired toxoplasmosis:
congenital or acquired toxoplasmosis? Clinical course: Usually benign and self-limited
o Symptoms usually resolve in a few weeks to
months
ACQUIRED TOXOPLASMOSIS
congenital or acquires toxoplasmosis? , 10-20% of patients with acute infection
may develop cervical lymphadenopathy and flu-like
illness
ACQUIRED TOXOPLASMOSIS
congenital or acquired toxoplasmosis? o Rare cases: ocular infection with visual loss can
occur
o Immunodeficient patients often have central
nervous system disease that may have
retinochoroiditis pneumonitis or other systemic
disease
acquired toxoplasmosis
In patients with AIDS,____ is
the most common cause of intracerebral mass
lesions and is thought to usually because by the
activation of chronic infection
toxoplasmic encephalitis
Toxoplasmosis in patients being treated with
immunosuppressive drugs may be due to either
newly acquired or reactivated latent infection
CRYPTOSPORIDIUM SPECIES
DIAGNOSTIC STAGE:
oocyst with 4 naked sporozoites
CRYPTOSPORIDIUM SPECIES INFECTIVE STAGE:
sporozoites
PATHOGENESIS
● acute , self-limiting diarrhea of 1-2 weeks duration
● Intense abdominal pain and bloating, anorexia, weakness
CRYPTOSPORIDIUM SPECIES
CRYPTOSPORIDIUM SPECIES DIAGNOSIS \● observe for mucosal changes and partial villous atrophy
● Trophozoites, schizonts, and merozoites can be found in
the microvilli
. BIOPSIES OF ILEUM AND JEJUNUM:
CRYPTOSPORIDIUM SPECIES DIAGNOSIS; ● Perform DFS and concentration techniques
- CRYPTOSPORIDIUM OOCYSTS IN STOOL
PNEUMOCYSTIS JEROVECI (CARINII) / PNEUMOCYSTIS
JEROVECI PNEUMONIA
DISEASE
● Interstitial plasmacellular pneumonia or pneumocytosi
Most common opportunistic infection in patients with HIV
infection
pNEUMOCYSTIS JEROVECI (CARINII) /
Organism is a rare cause of infection in the general population
PNEUMOCYSTIS JEROVECI (CARINII)
Frequent cause of morbidity and mortality in persons who are
immunocompromised especially patients with acquired
immunodeficiency syndrome (AIDS)
PNEUMOCYSTIS JEROVECI (CARINII)
is classified as a fungal pneumonia but does not respond to
antifungal therapy
PCP (PNEUMOCYSTIS JEROVECI PNEUMONIA)
Incidence has decreased as a result of a highly active
antiretroviral drugs
PCP (PNEUMOCYSTIS JEROVECI PNEUMONIA
PNEUMOCYSTIS JEROVECI HABITAT:
lungs
P.jiro MOT
airborne
○ small, round, with 8 uninucleated bodies
P.jiro cyst
crescent, sickle or pear-shaped with amoeboid
movement
P.jiro troph
Alveolar septal infiltration with plasma cells
P.jiro
● In the lungs: honeycombed masses of parasites within the
alveoli
P.jiro
P.jiro death due to
Asphyxia
a condition where the body does not get enough
oxygen, if left untreated it can cause coma or death
ASPHYXIA; p.jiro
treatment for P.jiro
Trimethoprim- sulfamethoxazole is the drug of choice.
Recognized as a opportunistic small bowel pathogen in
patients with HIV infection
ISOSPORA BELLI
P.jiro: The samples that we get will be stained
___ to demonstrate cyst and
trophozoites
methenamine silver
diagnosis P.jiro
Percutaneous needle biopsy of the lungs and lung aspirates
I.bel disease
human coccidiosis
ISOSPORA BELLI
INFECTIVE STAGE:
sporulated oocyst
Acute diarrhea with abdominal pain, it can be severe in
immunocompromised patients and children, eosinophilia has
also been reported
I.belli
Most commonly found in tropical and subtropical climates
● Can be diagnosed by identification of the oocyst in the stool
or biopsy, stools through DFS
I.belli
MORPHOLOGY:
● Immature oocyst:
○ Elongate ovoidal
● Mature oocyst:
○ Contains 2 sporocyst, each containing 4
sporozoites
ISOSPORA BELLI
ISOSPORA BELLI habitat
small intestine of man
Infects epithelial cells in the small intestines
● Symptoms which can last for weeks and results in
malabsorption and weight loss
I.belli
● Mild cases - mild abdominal pain and mucoid diarrhea
I.belli
Principal vector of plasmodium spp
Anopheles minismus var. flavirostris
what parasite: ➢ Single large compact ring or band forms
Plasmodium malariae
what parasite?Invades old RBCs
Plasmodium malariae
Schizont with merozoites arranges around central pigment
(resembles fruit pie)
p.malariae
ovoid gametocyte
p.malar
Small ring forms (1/6 diameter red cell), applique forms, double
nuclear dots
Plasmodium falciparum
Organisms invades all ages of red blood cells (most severe)
Plasmodium falciparum
arge pale red cells with Schuffner’s dots which may be oval
and fimbriated
Plasmodium ovale
Single compact ring
Plasmodium ovale
Only reticulocytes are invaded
. Plasmodium vivax
remains the gold standard
method for plasmodium spp identification
. Microscopic identification of the malarial parasites in thick and thin
blood smears stained with Giemsa or Wright’s stain is still important in
making the definitive diagnosis
produced by both sexual and asexual stages
and can distinguish between P. falciparum and non-P.
falciparum specie
Plasmodium LDH
Crescent/banana-shaped gametocytes
Plasmodium falciparum
Single large ring succeeded by amoeboid form in pale large
red cel
Plasmodium vivax
Round gametocyte
. Plasmodium vivax
disease? sudden massive intravascular hemolysis
resulting to hemoglobinuria
o Blackwater fever:
– detects Plasmodium-specific
antigens; these target antigens are called HRP II (Histidine-rich
protein
Immunochromatography
disease? red cells, organisms and pigment can block
the brain vessels
Cerebral malaria
Plasmodium____ infection is most likely fatal
Plasmodium falciparum
36- 48 hours Paroxysm
cycle
p.falci
72 hours
P.malariae
48 hours
p.ovale and p.vivax
appearance of
RBC size: Normal
lasmodium
malariae
infected rbc: Sometimes
enlarged;
frequently oval
with ragged
margins
p.ovale
Appearance of
RBC size:
Normal;
multiply
infected red
blood cells are
common
p.falci
infected rbc not enlarged
p.falci, malar, vivac
Appearance of
RBC size; Enrlaged;
maximum size
may be 1 – 2
times normal
RBC diameter
Plasmodium
Appearance of
RBC size; Enlarged;
approximately
20% or more of
infected RBCs
are oval
and/or
fimbriated
(border has
irregular
projections)
Plasmodium
ovale
Number of
merozoites; 6 – 14; average
is 8
p.oval
Number of
merozoites; 12 – 24;
average is 16
p.vivax
Number of
merozoites; 6 – 32
(average is
20 – 24)
p. fal
Schuffner’s
stippling
(precipitated
Hb): Maurer’s dots
occasionally
seen)
p. fal
Number of
merozoites; 6 – 12
(average is 8);
“rosette”
schizonts
p,mal
Schuffner’s
stippling
(precipitated
Hb): +
(James’ dots;
present in all
stages except
early ring
forms)
P.oval
Parasite
cytoplasm; Young rings are
small, delicate,
often with
double
chromatin
dots;
gametocytes
are crescentshaped or
elongated
p.fal
Schuffner’s
stippling
(precipitated
Hb): (Ziemann’s
dots rarely
seen
P,mal
Schuffner’s
stippling
(precipitated
Hb): +
(Schuffner’s
dots; present
with all stages
except in early
ring forms)
P.vivax
Parasite
cytoplasm Rounded,
compact
trophozoites
with dense
cytoplasm;
band-form
trophozoites
P.mal
Parasite
cytoplasm Rounded,
compact
trophozoites;
occasionally
slightly
amoeboid;
growing
trophozoites
have large
chromatin
mass
P.oval
Parasite
cytoplasm Irregular,
ameboid
trophozoites;
has “spread
out”
appearance
P. vivax
Trophozoite: Amoeboid
P.vivax
Trophozoite: Accole or
Applique forms
May have
multiple rings
p.falc
Appearance of
parasite
pigment: Black; coarse
and
conspicuous in
gametocytes
P.fal
Least common
Rarely fatal
May cause
relapses
P, oval
Appearance of
parasite
pigment: Dark brown,
coarse,
conspicuous
P.malar
Trophozoite; Band
P.malar
Appearance of
parasite
pigment: Golden brown,
inconspicuous
P.vivax
Trophozoite: Red cell
containing
trophozoite
may have
fimbriated
edges
P. oval
Appearance of
parasite
pigment: Dark brown,
conspicuous
P.oval
Shape of
gametocyte: Sausage or
crescentshaped
P.falc
Stages seen in
circulating
peripheral
blood: Rings and/or
gametocytes;
other stages
develop in
blood vessels
of internal
organs but are
not seen in
peripheral
blood EXCEPT
in severe
infection
p.falc
Shape of
gametocyte: round
P. mal, oval, vivac
Stages seen in
circulating
peripheral
blood:All stages
P.oval
Stages seen in
circulating
peripheral
blood: All stages; wide
range of
stages may be
seen on any
given film
p.vivax
Stages seen in
circulating
peripheral
blood: All stages; wide
variety of
stages usually
not seen;
relatively few
rings or
gametocytes
generally
present
P,malar
Highy mortality
p,falc
Rarely fatal
p. malar
slowly multiplying trophozoite contained in the cyst of T. gondii
Bradyzoites
Most common
Rarely fatal
May cause
relapses
p,vivax
extrusion of rapidly waving flagellum-like mircogametes from
microgametocytes
Exflagellation
mature sex cell of plasmodia
▪ Gamete –
– immature sexual form of plasmodia (male microgametocyteor
female microgametocyte) that is present in peripheral blood
Gametocyte
– development phase in the life cycle of malaria and coccidian
parasites in humans in which male and female gametes are formed
Gametogony
– exoerythrocytic schizont of P. vivax and P. ovale in the human liver,
characterized by delayed primary development; responsible for true relapse in
malaria
Hypnozoite –
also known as schizogony; leading to the production of merozoites
in some intestinal coccidians
Merogony –
– product of schizogonic cycle in malaria; produced in the liver (preerythrocytic cycle) and in the red blood cells (erythrocytic cycle); motile and
infects the red blood cells
▪ Merozoite –
– encysted form of the ookinete that occurs in the stomach wall of
Anopheles spp.
Oocyst
motile zygote of Plasmodium spp; formed by microgamete
fertilization of macrogamete
▪ Ookinete –
ever, chills, sweats syndrome in malaria; spiking fever corresponds to
the release of merozoites and toxic material from the rupturing parasitized red
blood cells, and shaking chills occur during subsequent schizont development
Paroxysm
– increased severity of a disease after a remission or following
treatment as a result of an inadequate immune response by the host or
inadequate response to treatment
▪ Recrudescence –
a recurrence of illness/signs and symptoms of a disease after a period
of improvement; In malaria, it is caused by the reactivation of hypnozoites in the
liver that begins a new cycle in red blood cells; occurs only in Plasmodium vivax
and P. ovale infections
▪ Relapse -
(Asexual cycle) occurs on the epithelial cells of the intestinal
mucosa producing schizonts
Schizogony
developed stage of asexual division of the sporozoa; ruptures to
produce merozoites
Schizont
occurs within the intestinal lumen of the invertebrate
host. End product → sporozoite
Sporogony
slender, spindle-shaped organism; infective stage of malaria
parasites; inoculated into humans by the bite of an infected female mosquito; It
is the result of the sexual cycle in the Anopheles mosquito
Sporozoite
– rapidly multiplying stage in the development of the tissue phase of
certain organisms such as Toxoplasma gondii
Tachyzoites
feeding or growing stage in the asexual cycle
Trophozoite
union of the macrogamete and microgamete; fertilized ovum/ova
before cell division
Zygote
