Parasites: Protozoa of the Blood Flashcards
List the protozoa of the blood
- Trypanosoma Cruzi
- Babesia
- Plasmodium Malariae
- Plasmodium Ovale
- Plasmodium Vivax
Plasmodium Falciparum - Leishmania Braziliensis
- Leishmania Donovani
Chagas Disease
a parasitic blood infection caused by Trypanosoma cruzi
“kissing bugs”
“kissing bugs” bite around the mouth and deposit feces contaminated with Trypanosoma cruzi, which can later be introduced by scratching the area
Trypanosoma cruzi is transmitted by the
reduviid or “kissing bug”
Chagas disease can lead to
- an abnormal dilation of the colon (megacolon)
- myopericarditis and dilated cardiomyopathy
- megaesophagus
diagnosis of Chagas disease can be made by
observation of trypomastigotes (bloodstream form of Trypanosoma cruzi) on microscopic examination of blood smear
diagnosis of Chagas heart disease can be made by observation of
trypanosomes within cardiac myocytes on microscopic examination of heart biopsy
Trypanosoma cruzi infects the heart by
burrowing into the endocardium
_________ is effective against Trypanosoma cruzi
nifurtimox
babesiosis is a
tick-borne illness
the Ixodes tick (the vector of Babesia spp.) is a
deer tick
Babesia spp. can cause
hemolytic anemia
babesiosis can present with
jaundice (usually later in the course of illness)
The _____ ____ is the vector of Babesia
Ixodes tick
babesiosis often presents with
- irregular fevers
2. irregularly cycling fevers
_______ ______ ____ is a risk factor for severe babesiosis
- sickle cell disease
2. asplenia
thick blood smear in Babesia spp. infection will show
intracellular and extracellular ring forms and classic tetrad “Maltese Cross” forms inside RBCs
Babesia spp. protozoa can have a
tetrad “Maltese Cross” appearance inside RBCs
Babesia spp. protozoa are predominantly found in the
northeastern region of the United States
_______ is effective against Babesia spp.
- atovaquone
2. azithromycin (a macrolide)
Plasmodium spp. parasites can be visualized on
thick or thin blood smear prepared with Giemsa stain
Plasmodium malariae infection presents with a
quartan fever cycle (72 hrs)
Plasmodium vivax and ovale produce
dormant hypnozoites
dormant hypnozoites
hepatocytes
Plasmodium vivax and ovale infections present with
a tertian fever cycle (48 hrs)
Plasmodium falciparum infection presents with
an irregular fever pattern
RBCs parasitized by Plasmodium falciparum can occlude the
- capillaries of the brain, leading to cerebral malaria
- vessels of the kidneys
- vessels of the lungs
Plasmodium falciparum gametocytes appear
banana-shaped on peripheral blood smear
Antimalarial agents
- chloroquine
- primaquine
- mefloquine
- Proguanil
- quinine/quinidine
the treatment for malaria involves
chloroquine, which blocks Plasmodium heme polymerase
Chloroquine blocks
plasmodium heme polymerase
because the hypnozoites of Plasmodium vivax and ovale lie dormant in hepatocytes so _____ _____ is not an effective treatment
chloroquine alone
Treatment of plasmodium vivax and ovale infections
primaquine is used in addition to chloroquine
primaquine is used in addition to chloroquine in cases of Plasmodium vivax and ovale infections because
it can destroy hypnozoites in the liver
mefloquine is effective against
resistant strains of Plasmodium spp.
_________ should be used prophylactically by travelers visiting regions where Plasmodium spp. are resistant to chloroquine
- mefloquine
2. atovaquone-proguanil
Quinone antimicrobial agent
atovaquone
atovaquone-proguanil is effective against
resistant strains of Plasmodium spp.
Artemisinins
a class of antimalarial agents
both artemisinins and atovaquone-proguanil can be used for
severe Plasmodium falciparum infection
____ ______ ____ is protective against Plasmodium falciparum
sickle cell disease/trait
_____ ______ is used in the case of severe malaria infection
IV artesunate
________ is effective against resistant strains of Plasmodium spp.
quinine (or quinidine)
a side-effect of quinidine is
cinchonism, including tinnitus
_______ and _____ are delivered IV for severe malaria
artesunate and quinine (or quinidine)
Anopheles mosquitoes carry
Plasmodium spp. sporozoites in saliva
once an Anopheles spp. mosquito vector takes a blood meal
once an Anopheles spp. mosquito vector takes a blood meal (and introduces Plasmodium spp. sporozoites into human hosts), the sporozoites mature into merozoites in the liver
in the liver, merozoites of Plasmodium spp
rupture from hepatic schizonts (and hepatocytes), which enter the bloodstream where they infect RBCs
the Plasmodium life cycle continues in
the Plasmodium life cycle continues in RBC: trophozoite → schizont → merozoites (which rupture from schizont and RBC) → infect more RBCs
immature trophozoites of Plasmodium spp. appear as
ring forms inside RBCs
merozoites of Plasmodium spp. are capable of
initiating sexual development (gametocytes)
vertebrates are the hosts of
Leishmania braziliensis
Leishmania braziliensis can cause
cutaneous leishmaniasis, which presents with papules and plaques that progress to ulcerative lesions
________ are the vector of Leishmania braziliensis
sandflies
______ are the non-flagellated intracellular form of Leishmania spp., which can be found within macrophages
amastigotes
numerous amastigote nuclei of Leishmania donovani can be seen in
the cytoplasm of macrophages on microscopy
Leishmania donovani causes
visceral leishmaniasis (also called black fever or kala-azar)
a characteristic feature of visceral leishmaniasis
a characteristic feature of visceral leishmaniasis (caused by Leishmania donovani) is spiking fever
visceral leishmaniasis (caused by Leishmania donovani) affects
the bone marrow, which can lead to pancytopenia
a characteristic feature of visceral leishmaniasis (caused by Leishmania donovani) is
hepatosplenomegaly
treatment of leishmaniasis includes
stibogluconate
__________ is used in the treatment of visceral leishmaniasis (caused by Leishmania donovani)
amphotericin B
