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Clinical parasitology
deals with the parasites of the man and their medical significance
Parasitology
area of biology concerned with the phenomenon of dependence of one living organism on another
Host
larger organism which provides physical protection and noursihment
Definitive/ Final Host
in which parasites attain sexual maturity (man)
Immediate Host
Harbors the sexual or larval stage of the parasite
Paratenic/ Transport Host
No development occurs but the parasite remains alive and infective
Reservoir Host
allow parasite’s life cycle to continue and become additional sources of human infection
Vector
transmits parasites to humans or animals
Zoonosis
parasites found in animals are transmitted to human (usually through consumption)
Obligate parasites
Cannot exist without a host
Free living stage
Live outside the host within a protective eggshel or cyst
Facultative parasites
live either a parasite or a free-living existence
type of parasites that is flexible
Infection
produced by endoparasites found inside the body
Infestation
produced by ectoparasites outside the body
Commensalism
only one parter benefits from the association but the host is neither helped nor harmed
Mutualism
Relationship is beneficial both to the parasite and the host
Parasitism
one partner benefits at the enzyme of the other
parasitism
most type of relationship the parasites adopt to
Pseudopodia/ Pseudopods
temporary extensions of the cells/ plasma membrane and used for locomotion and feeding and movement is like protoplasmic streaming
pseudopods
utilizes iron from RBC
flagella
slender whip-like structure
cilia
Tiny, hair-like structure composed of kinetids
kinetids
functional unit of cilia
Binary fission/ longitudinal binary fission
parasites produces asexually via
2 daughter cells
how many daugher cells will Binary fission/ longitudinal binary fission give off?
multiple fission
nucleus of the parent divides into many daughter cells by?
sexual reproduction
involves the participation of 2 whole cells
Gametogony
meiosis, sexual reproduction by union of 2 whole cells
gametes
daughter cells is also called as
mouth
most common point of entry
fomites
exposure from inanimate objects
traumatic damage
when the parasite puctures the skin producing wounds, that’s when trauma happens
Lytic necrosis
enzymes are involved, enzymes are released by the parasites and digest possible food that is available in the environment
surgical intervention
method of treatment for macroorganisms
Cellular proliferation and Infiltration
there is an increase in the RBCs/ WBCs at the site of parasitic infection
Trypanosoma cruzi
etiologic agent of Chagas disease or American trypanosomiasis
Stercoraria
group of Trypanosoma cruzi
myocytes and reticuloendothelial sytsem
heavily infected cell of Trypanosoma cruzi
reduviid bug
what is the vector of Trypanosoma cruzi?
amastigotes
diagnostic stage of Trypanosoma cruzi
trypomastigotes
infective stage of Trypanosoma cruzi
bloodstream
in humans trypomastigotes are found in
tissue cells
in humans amastigotes is found in
midgut
in vector amastigote, epimastigote and promastigote is found in
hindgut
in vector trypomastigote is found in
amastigote
round/ovoid shape
1.5-4 micrometer
found in small groups of cysts like collections in tissues
trypomastigote
15-20 micrometer
pointed posterior end
has an undulating membrane with 2-3 undulations
trypomastigote
has a single thread-like flagellum
C-shaped in stained specimens
Trypanosoma cruzi
associated with megasyndrome
acute stage
focal or difuse inflammation mainly affecting myocardium
Chagomas
furuncle like lesions associated with induration, central edema, regional lymphadenopathy also represents as a site of entry for parasite
Romana’s sign
eyelid swelling
Latent/indeterminate phase
this stage is usually asymptomatic but still capable of transmitting the disease through vectors, blood transfusion and organ transplant
1/3
about ____ developes to chronic stage
chronic stage
stage that is multifactorial which means that it is dependent on the reaction between the parasite and the host
heart
primary affected organ in chronic stage
megasyndrome
fibrotic reactions leads to ____
direct visualization of the parasites in thick and thin blood smears using Giemsa stain
definitive diagnosis of acute stage
2 months
trypomastigotes can only be detected in the first ____ of acute disease
2 techniques
for chronic stage, it recommends at least ____ to show a postive result
Nifurtimox and Benznidazole
used to treat Trypanosoma cruzi
10 million
Trypanosoma cruzi infected more than ___ worldwide
Latin America
most cases of Trypanosoma cruzi is in
Central and South America
endemic areas are ___
third
In 2003, it ranked as ___ as the leading cause of parasitic infection worldwide
Trypanosoma brucei gambiense, Trypanosoma brucei rhodesiense, Trypanosoma brucei brucei
What are the 3 Trypanosoma brucei or also known as the Trypanosoma complex
Human African Trypanosomiasis
Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense causes
African sleeping sickness
a highly fatal disease
Trypanosoma brucei brucei
it affects wild and domestic animals
east Africa
Trypanosoma brucei rhodesiense is endemic in ____
Western and Eastern region of Sub-Saharan Africa
Trypanosoma brucei gambiense is endemic in _____
Trypanosoma brucei gambiense
primarily affects human but utilizes dogs, pigs and sheep as a reservoir hosts
Trypanosoma brucei rhodesiense
primarily a zoonosis of cattle and wild animals
Trypanosoma brucei rhodesiense
humans are accidental hosts
Trypanosoma brucei gambiense
chronic type of sleeping sickness
Trypanosoma brucei rhodesiense
more rapid and acute fatal form of sleeping sickness
Trypanosoma brucei gambiense
Causes 95% of cases of Human African Trypanosomiasis
Trypanosoma brucei rhodesiense
Causes 5% of cases of Human African Trypanosomiasis
epimastigote and trypomastigote
the only 2 stages of Trypanosoma brucei complex
chancre
initial lesion, painful, local, pruritic, erythematous located at bite site progressing into a central eschar, resolving after 2-3 weeks
Trypanosoma brucei gambiense
chancre is more common in
hemolymphatic
early phase is also known as
1-6 months
early phase lasts for how many months
Winterbottom’s sign
for Trypanosoma brucei gambiense- posterior cervical lymph nodes are enlarged, nontender and rubbery
Late phase
This phase involces the CNS
meningoencephalitic
late phase is also known as
3-10 months
Trypanosoma brucei gambiensein late phase occur ____ after initial infection
after few weeks
Trypanosoma brucei rhodesiense manifests ___
Kerandel’s sign
deep, delayed hyperesthesia
Antigenic variation
ability of trypanosomes to continuously change its surface coat so that the host’s antibodies can’t recognize the parasite in subsequent waves of parasitemia
Early phase/ hemolymphatic
diagnosis is usually done in what phase?
Giemsa stain
used for thick and thin blood film
Buffy coat concentration
recommended to detect parasites in low numbers
Card agglutination test (CATT)
detect circulating antigens in persons infected with Trypanosoma brucei complex
rapid and highly specific method for screening
available commercially
Intravenous Suramin Sodium
used to treat Trypanosoma brucei gambiense/ rhodesiense in early phase
Intramuscular pentamidine
used to treat Trypanosoma brucei rhodesiense in early phase
Intravenous melarsoprol
drug of choice for both type of sleeping sickness during the late phase
Nitrofurazone
second line of drug for late phase
Eflornithine
may also be used during the early phase
less toxic than melarsoprol
only effective against Trypanosoma brucei gambiense
Trypanosoma brucei rhodesiense
is an occupational hazard for persons working in game reserves and game parks
Note 
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