Helminths Flashcards
a symbiotic relationship that is of benefit to one party or symbiont
Parasitism
Parasites that live outside
the host’s body are referred to as
ectoparasites
Parasites that live INSIDE
the host’s body are referred to
as
endoparasites
If more than one
host is involved, the ______ is the one that harbors the adult or sexual stage of the parasite or the sexual phase of the life cycle.
definitive
host
harbors the larval or asexual stage of the parasite or the
asexual phase of the life cycle
intermediate
host
is a living organism that can serve as a host in a particular parasite’s life cycle, but is not a
usual host in that life cycle.
accidental host
A parasite THAT cannot continue its life cycle.
Dead-end hosts
is an organism that can be parasitic but does not have to live as a parasite
facultative parasite
on the other hand, has no
choice; to survive, it must be a parasite
obligate parasite
is the study of parasites
that cause human disease
Medical parasitology
these microbes are classified
taxonomically by their
mode of locomotion.
Protozoa
Amebas
(amebae) move by means
pseudopodia
Protozoa classified as ______ have no pseudopodia, flagella, or cilia, and therefore exhibit
no motility.
Sporozoa (sporozoans)
is caused by various species of
flagellated protozoa
and is usually
transmitted via the
bite of an infected
sand fly
Leishmaniasis
three forms of leishmaniasis
cutaneous,
mucocutaneous (or mucosal), visceral
this form of leishmaniasis starts with a papule that enlarges into
a craterlike ulcer
cutaneous
this leishmaniasis is characterized by fever, enlarged liver and spleen, lymphadenopathy, anemia, leukopenia, and progressive emaciation and
weakness
Visceral leishmaniasis, also known as kala-azar,
this type of protozoa is principally a zoonosis and
is usually transmitted via the bite of an infected sand fly.
Transmission by blood transfusion and person-to-person contact have been reported
Leishmaniasis
Protozoal infections of the eyes include
conjunctivitis and
keratoconjunctivitis
is a systemic sporozoan infection that, in immunocompetent persons, may be asymptomatic or resemble infectious
mononucleosis
Toxoplasmosis
a protozoal gastrointestinal infection that may be
asymptomatic, mild, or severe accompanied by dysentery, fever, chills, bloody or mucoid diarrhea or constipation,
Amebiasis
a protozoal gastrointestinal infection of the colon causing
diarrhea or dysentery, colic, nausea, and vomiting.
Balantidiasis
is a gastrointestinal infection caused by a coccidial
protozoan
Cryptosporidiosis.
s a protozoal infection of the
duodenum
Giardiasis
Protozoal Infections of the
Genitourinary Tract
Trichomoniasis
a sexually transmitted protozoal disease affecting both men and women. is usually symptomatic in women, causing vaginitis
Trichomoniasis
Infects colon with secondary infection of liver. patients pass noninfectious trophozoites as well as infectious cysts in
stools
Entamoeba histolytica
Infects lower small intestine. * Diagnosis by modified acid-fast stain of stool sample ;oocyst
Cryptosporidium parvum
*Infection usually results from drinking contaminated water.
Acute infection shows sudden onset with foul smelling, watery diarrhea.
Giardia lamblia
a systemic disease caused by flagellated protozoa in the
bloodstream, known as hemoflagellates.
African Trypanosomiasi
The frequency with which the cycle of chills, fever, and sweating is repeated is referred to as periodicity what protozoal infection is this
Malaria
means parasitic worm.
helminth
The helminths that infect humans are always
endoparasites
The two major divisions of helminths
roundworms (nematodes)
flatworms
The flatworms are further divided into
tapeworms (cestodes)
flukes (trematodes)
The stages of the
typical helminth life
cycle are the
egg,
the larva
adult worm.
The host that harbors the larval stage is called the
intermediate host
host that harbors the adult
worm is called the
definitive host
(also known as
“river blindness”)
Onchocerciasis
3 classes of artbropods
insects (class Insecta),
arachnids (class Arachnida),
crustaceans
an arthropod in whose
body the pathogen multiplies or matures (or both).
biologic vector
- Humans develop malaria after the injection of
Plasmodium __________ into the bloodstream by an
infected female Anopheles mosquito when she takes a
blood meal.
a. male and female gametocytes
b. schizonts
c. sporozoites
d. trophozoites
c
These Plasmodium life cycle stages must be ingested
by a female Anopheles mosquito for the Plasmodium
life cycle to continue in the mosquito.
a. male and female gametocytes
b. schizonts
c. sporozoites
d. trophozoites
a
Which of the following protozoal diseases is not
transmitted via an arthropod vector?
a. African trypanosomiasis
b. American trypanosomiasis
c. babesiosis
d. giardiasis
d
. Which of the following protozoal diseases is least
likely to be transmitted via blood transfusion?
a. American trypanosomiasis
b. babesiosis
c. malaria
d. trichomoniasis
d
Which of the following protozoal diseases is least
likely to be transmitted via an infected food handler
who fails to wash his or her hands after using the
bathroom?
a. amebiasis
b. cryptosporidiosis
c. giardiasis
d. toxoplasmosis
d
You are visiting a friend whose parents raise pigs.
Which of the following diseases are you most likely
to acquire by drinking well water at their farm?
a. amebiasis
b. balantidiasis
c. cryptosporidiosis
b
You are working on a cattle ranch. Which of the following diseases are you most apt to acquire as you
perform your duties at the ranch?
a. amebiasis
b. balantidiasis
c. cryptosporidiosis
d. giardiasis
c
. Which of the following protozoal diseases are you
most likely to acquire by eating a rare hamburger?
a. amebiasis
b. balantidiasis
c. giardiasis
d. toxoplasmosis
d
Which of the following associations is incorrect?
a. African trypanosomiasis . . . tsetse fly
b. amebiasis . . . fecally contaminated water
c. Chagas’ disease . . . mosquito
d. toxoplasmosis . . . cats
c
Which of the following is an example of an infectious disease that is caused by a facultative parasite?
a. African trypanosomiasis
b. giardiasis
c. malaria
d. PAM
d
