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63 Cards in this Set
- Front
- Back
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What are the four major protozoal groups classified by their mode of locomotion?
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Amebas: extend cytoplasmic projections
Flagellates: rotate whip flagella Ciliates: move by synchronous beating of hair like cilia Sporozoa: Nonmotile adult forms |
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What are the clinically relevant Protozoan flagellates? (4 of them)
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Giardia Lamblia
Trichomonas Vaginalis Trypanosoma Species Leishmania Species |
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What are the clinically relevant protozoan Ameba?
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Entamoeba Histolytica
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What are the clinically relevant protozoan Sporozoan?
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Cryptosporidium Parvum
Plasmodium Species Toxoplasma Gondii Babesia |
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What are 2 symptomatic characteristics of Entamoeba Histolytica infection?
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Dysentery
Liver abscess |
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What protozoa can cause this clinical presentation: A patient presents with an enlarged, tender liver. Ultrasound analysis reveals a solitary cyst.
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Entamoeba histolytica trophs can invade the liver and cause an abcess
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What protozoa can cause this clinical presentation: A South African businessman presents with fever, chills and dark colored urine. A history reveals that the symptoms appear to be showing a periodicity of fever spikes approximately every 48 hours. A blood smear demonstrates multiply infected erythrocytes and crescent-shaped gametocytes.
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Plasmodium falciparum
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What protozoa would most likely cause a maternal infection leading to an undergrown fetus with a small head, purplish rash and enlarged liver
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Toxoplasma is acquired by ingesting oocytes (often shed by cats) or transplacental transmission. Primary infection during pregnancy puts a patient at risk, especially during the first and second trimester
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What flagellated protozoan associated with diarrhea?
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Giardia lamblia
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What sporozoan protozoan causes severe diarrhea in AIDS pts and watery diarrhea in non-HIV + ppl?
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Cryptosporidium parvum
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What organism causes this presentation: Your younger bro returned from summer camp in the Rockies. You notice that you can’t get into the broom at home bc he seems to spend all day there. When u ask him if he has any probs, he says he is having frequent diarrhea. Exam of stool revealed polynucleated cysts ~50 microns in diameter + few smaller flagellated protozoans.
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Giardia lamblia
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What is the laboratory test confirm a diagnosis of Malaria?
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Thick smear of the peripheral blood
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What is the current drug of choice that is administered prophylatically to protect travelers when visiting areas in Africa in which malaria is endemic?
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Mefloquine - As there is often chloroquine resistance in malarial areas
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What dz does case describe: A 5-yr old, from Mexico is seen in ER bc of painless swelling around the rt eye. The lid and globe are mildly inflamed. The dad states daughter has had a low temp, headache, and does not feel well. Exam fails to reveal trauma, but the lymph nodes around the hd and neck are slightly tender and swollen. father states that “wild bedbugs” are found in the home
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Chagas disease
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Why does Plasmodia cause fever that reoccurs with a periodicity of either three or four days?
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Emergence of intra-erythrocytic parasites
Lysis of red cells causes release of pyrogens that cause fever. This lysis is synchronized in the infected person |
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What is the vector for Chagas Dz?
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Reduviid insects: This "kissing" bug feeds at night, biting the lips or near the eyes
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Sickle cell disease is associated with increased resistance to what disease
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Malaria
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What protozoan parasites have arthropod vectors?
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Trypanosoma Cruzi - Chagas' Disease: Reduviid bug
T. Gambiense/ Rhodesiense - African Sleeping Sickness: Tsetse fly Leishmania donovani Kala-azar: Sandfly Babesia - Babesiosis: Ixodes Tick Plasmodium - Malaria: Female anopheles mosquito |
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What protozoan parasite can cause this presentation: A 32 year old male who has spent the summer in the Middle Atlantic States hiking the Appalachian Trail complains of fever, chills, arthralgia and malaise. Physical examination detects a palpable hepatosplenomegaly. Laboratory tests for Lyme disease are negative.
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Babesia microti is passed to man via ticks which would be commonly encountered on a hike. The patient's symtpoms are very consistent with Babesia infection, a disease that's rather similar to Lyme disease
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What Protozoans are treated with Metronidazole (FLAGYL)?
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Entamoeba histolytica
Giardia Lamblia Trichomonas Vaginalis |
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What is the feeding form of most protozoa?
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Trophozite
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What is the definitive host of Toxoplasma Gondii?
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CAT
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What is the treatment for Toxoplasma Gondii?
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Pyrimethamine / sulfadiazine
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What is the most pathogenic species of plasmodium?
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Plasmodium falciparum
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What forms of plasmodium can remain dormant in the liver?
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Plasmodium Vivax
Plasmodium Ovale |
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What is the vector for Malaria (Plasmodium parasite)?
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Female anonpheles mosquito
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What is the mechanism of infection for plasmodium vivax?
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Uses duffy bld group Ag to infect reticulocytes
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What type of malaria does plasmodium ovale cause?
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Benign Tertiary Malaria
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What type of malaria does plasmodium malariae cause?
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Quartan Malaria
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What is the sexual and asexual phases of malaria caused?
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Sexual: sporogony
Asexual: schizogony |
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What is the treatment for malaria?
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Chloroquine
Mefloquine: for resistant strains Primaquine: prevent relapse pyrimethamine + sulfadoxine |
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What form of plasmodium is released in mosquito’s saliva?
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Sporozoites
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What is the insect involved in the spread of Leishmaniasis ?
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Sandfly
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How is Entamoeba Histolytica (Amebiasis) transmitted?
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Cysts in water
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How is Giardia Lambia(Giardiasis) transmitted?
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Cysts in water
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How is Cryptosporidium transmitted?
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Cysts in water
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How is Toxoplasma Gondii transmitted?
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Cysts in meat or cat feces
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How is Trichomonas Vaginalis transmitted?
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Sexually
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What is the vector for Babesia/
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Ixodes Tick
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How is African Sleeping Sickness
(T. gambiense/rhodiense) transmitted? |
Tsetse Fly
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What is the clinical picture of Babesiosis?
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Mild Malaria like symptoms
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What is the clinical picture of Toxoplasmosis in pregnancy?
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Birth defects
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What is the clinical picture of Toxoplasmosis in HIV + ppl?
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Brain Abscess
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What is the clinical picture of Malaria?
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cyclic fever, headache, anemia, splenomegaly
P. Falciprum: cerebral malaria |
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What is the clinical picture of Vaginitis caused by Trichomonas vaginitis?
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Foul-smelling, greenish discharge, itching, burning
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What is the clinical picture of Chagas' Dz?
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Swelling around eye and hrt dz
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Which protozoans infect the intestines?
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Entamoeba Histolytica
Giardia Lamblia Cryptosporidium parvum |
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How do you diagnose the protozoans that infect the intestines?
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Cysts in stool, must use acid-fast to see cryptosporidium parvum and trophozoites may be present for both Giardia Lamblia and Entamoeba Histolytica
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How do you diagnose Trichomonas Vaginalis?
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Trophozoites seen on a wet mount
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Which protozoans infect the blood?
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Babesia, Plasmodium, Toxoplasma gondii, Trypanosoma species and Leishmania species
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How do you diagnose the protozoans that infect the blood?
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Blood Smear, Babesia appears as Maltese cross w/ no RBC pigment and Toxoplasma: serology IgG/IgM
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Babesia
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What organism causes this presentation in RBCs?
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What is the treatment for African trypanosomes causing African Sleeping Sickness?
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Diamidines, arsenicals; DFMO at later stages
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What are the clinical differences between the 2 organisms that cause African Sleeping Sickness ?
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Trypanosoma brucei gambiense – SLOW CNS involvement
Trypanosoma brucei rhodiense – QUICK CNS involvement |
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What is a trypomastigote?
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Hemoflagellate form found in man and animals
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What is a epimastigote
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Hemoflagellate form found in insect vector, is infectious
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What is a promastigote
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Hemoflagellate form found in found in insect vector and easiest to culture
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What is a amastigote?
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Hemoflagellate form intracellular form found in man. Only African trypanosomes do not have this stage.
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What cell type does Leishmania infect?
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Macrophages
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How do you diagnose Leishmania?
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Tissue biopsy of macrophages
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How does Leishmania evade the host immune system?
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superoxidase dismutase to resist killing by lysosomal enzymes
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How does host cell immunity exacerbate Leishmania (braziliensis, major, tropica) lesions?
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Immunity associated with production of IFN Gamma and TNF by CD4+ cells-
exacerbation of lesions associated with high levels of IL-4 which inhibits activation of macrophages by TNF; blocked production of cytokines |
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What is the clinical picture of kala-azar caused by Leisshmania donovani?
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fever, wt loss, hepatosplenomegaly, anemia, death.
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