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106 Cards in this Set
- Front
- Back
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Adult flukes live in _______ in humans.
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S. japonicum & S. mansoni=mesenteric venules
S. haematobium=bladder venules |
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Intermediate host of blood flukes?
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Snail
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Infective stage of blood fluke (schistosoma)?
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Cercariae in water directly penetrate skin of man
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Definitive host of blood flukes?
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Humans
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Conspicuous lateral spine/spike
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S. mansoni
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Inconspicuous lateral knob/spike
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S. japonicum
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Diagnostic stage of blood flukes:
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Egg in feces (urine for S. hematobium)
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Associated with Cirrhosis of liver (1)
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S. mansoni
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Associated with Bladder cancer (1)
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S. haematobium
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Parasites that appear in URINE (1):
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Schistosoma haematobium (egg)
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Parsites appear in MUSCLES (1):
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Trichinella spiralis (larvae)
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Parasites appear in BLOOD (1):
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Microfilaria
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Parasites appear in SPUTUM (3):
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-Paragonimus westermani (egg)
-Ascaris lumbricoides (adults) -Strongyloides stercoralis (adults, larva, eggs) |
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Parasites appear in LIVER/BILE (1):
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Echinococcus granulosus (larvae)
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What is a gravid proglottid?
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Sexually mature segment of a cestode.
Contains male and female reproductive organs. Uterine branches. |
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List the 7 tapeworms:
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-Taenia saginata (Beef tapeworm)
-Taenia solium (Pork Tapeworm) -Hymenolepis nana (Dwarf Tapeworm) -Hymenolepsis diminuta (Rat Tapeworm) -Diphyliobothrium latum (Broad fish tapeworm) -Echinococcus granulosus (Hydatid Tapeworm) -Dipylidium caninum (Dog tapeworm) |
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Taenia saginata has an armed/unarmed scolex?
Taenia solium has an armed/unarmed scolex? |
T. saginata = Unarmed
T. solium = Armed |
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Taenia saginata has more/less gravid proglottids than Taenia solium?
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More
(remember because "saginata" has more letters than "solium") |
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Taenia saginata is the what tapeworm?
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Beef
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Taenia solium is the what tapeworm?
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Pork
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Which cestode causes cysticercosis, and how does it do so?
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Taenia solium, pork tapeworm.
Ingestion of egg instead of larvae. |
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What is the most common tapeworm in the US?
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Hymenolepsis nana (Dwarf Tapeworm)
Doesn't require an intermediate host. |
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Infectious stage of Taenia species?
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Ingestion of larvae in undercooked beef/pork
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Infectious stage of Hymenolepsis nana?
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Egg
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How are H. nana and H. diminuta eggs distinguished?
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H. nana have polar filaments
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How do humans become infected with Hymenolepsis diminuta?
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Consumption of infected beetle
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Which cestode has a rosette-like gravid proglottid and shallow grooves in the scolex?
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Diphylobothrium latum
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What cestode can cause B12 deficiency?
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Diphylobothrium latum
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What technique should not be used with operculated eggs?
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Floatation
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Intermediate and Definitive hosts of Ecchinococcus granulosus:
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Intermediate: Sheep
Definitive: Dog |
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How is Ecchinococcus granulosus diagnosed?
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Find hydatid cysts (hydatid sand inside when drained).
Serology. Cyst mass in organ. |
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Eccinococcus granulosus resides where in the human?
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Tissues/organs
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What causes the disease condition of larval migrans?
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When animal hookworm or ascardis causes disease in the human.
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What is cutaneous larval migrans caused by?
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Ancyclostoma (hookworm)
Skin penetration |
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What is visceral larval migrans caused by?
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Ascarid worm (Toxocara canis)
Larvae moves around in tissues (very hard to diagnose/find) |
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Adult Trichinella spiralis produce:
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Larvae, not eggs
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Microfilariae require what type of intermediate host?
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Arthropod
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What are the 4 filarial worms?
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Wuchereria bancrofti
Brugia malayi Loa loa Onchocerca volvulus |
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What are the 8 blood and tissue nematodes?
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Trichinella spiralis
Dracunculus medinensis Wuchereria bancrofti Brugia malayi Loa loa Onchocerca volvulus Cutaneous larval migrans (Ancyclostoma) Visceral larval migrans (Toxocara canis) |
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Microfilariae are diagnosed by:
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Observing thick and thin Giemsa stained blood smears
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What causes elephantiasis, and how are the organisms differentiated?
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Wuchereria bancrofti and Brugia malayi, via Blockage of lymphatic system.
Speciated by examining microfilarial sheath. |
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What causes river blindness and how is it diagnosed?
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Onchocerca volvulus.
Adult in skin snip from nodules |
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How is Loa loa transmitted?
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Chrysops Fly
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What is the characteristic symptom of Loa loa?
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Calabrar swellings (transient inflammation and swelling)
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How is Onchocerca volvulus transmitted?
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Black Fly
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Brugia malayi is found mainly where?
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Asia and Indian subcontinent
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What type of organism can be found with periodicy (nocturnal, diurnal)
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Microfilaria
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Where does the adult Trichinella spiralis worm live?
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Small intestine
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How is Wuchereria bancrofti transmitted?
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Mosquito
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How is Brugia malayi transmitted?
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Mosquito
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How is Dracunculus medinensis transmitted?
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Consuming infected copepods
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Dracunculus medinensis is what type of worm?
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Nematode
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The intermediate host contains what life cycle stage?
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Larvae/non sexually mature
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The definitive host contains what life cycle stage?
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Sexually mature/adult
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Which parasites (broad types) are hermaphroditic (2)
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Cestodes and Trematodes (except Schistosoma)
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List the 6 intestinal nematodes and their common names:
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-Ascaris lumbricoides (lg. intestinal roundworm)
-Enterobius vermicularis (pinworm) -Trichuris trichiura (whipworm) -Strongyloides stercoralis (threadworm) -Necator americanus (new world hookworm) -Ancylostoma duodenale (old world hookworm) |
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Most common helminth in humans is:
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Enterobius vermicularis
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Strongyloides stercoralis larvae must be differentiated from what, by what means?
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From hookworm eggs, by examining buccal cavity
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Necator americanus has:
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Cutting plates
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Ancyclostoma duodenale has:
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2 sets of teeth
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Which intestinal nematodes have a pulmonary stage (3)?
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Ascaris lumbricoides
Hookworm (Necator and Ancyclostoma) Strongyloides stercoralis |
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Which intestinal nematodes infect via skin penetration (2)?
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Strongyloides stercoralis
Hookworms |
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What organism is transmitted by the Tse Tse fly?
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Trypanosoma species
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Time limits for stool specimens?
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30 mins liquid
24 hours formed |
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For which protists do knowing the intermediate vs. definitive hosts matter?
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Apicomplexans
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What is usually the definitive host for protists?
What are the exceptions (3): |
Humans.
Toxoplasma, Plasmodium, Babesia. |
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Every stool sample should be fixed in what?
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Both PVA and Formalin.
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Trichrome stain can be done on a specimen preserved in what?
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PVA
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Concentration is performed on samples preserved in what?
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Formalin
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Modified acid fast stain is performed on sampled preserved in what?
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Formalin
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Iodamoeba butschlii is/is not a pathogen?
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Is not.
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What amoeba cross the blood/brain barrier (2)?
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Naegleria fowleri (primary amoebic meningoencepalitis)
Acanthamoeba (granulomatus amoebic encephalitis) |
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What organisms are routinely detected by rapid antigen tests in the hospital lab?
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Cryptosporidium and Giardia
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What stain is used for cryptosporidium?
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Modified acid fast stain
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Toxoplasmosis is diagnosed by:
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Serology
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Name the 4 species of plasmodium:
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falciparum
vivax ovale malariae |
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Life cycle stages of plasmodium: (3)
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Trophozoite
Schizont Merozoite |
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What are the cycles of malarial illness called? What causes it?
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Paroxysms (chills, fever, profuse sweating; 4-6 hours)
Lysing of RBCs |
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The reduviid bug transmits:
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Chagas Disease (T. cruzi)
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how is chagas disease (trypanosoma cruzi) diagnosed?
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Finding amastigotes in tissue (v. hard to diagnose)
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Where does the adult schistosoma worm live?
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In the veins around the intestines. it is NOT FOUND IN THE CIRCULATION.
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What is Winterbottom's sign?
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Inflammation of the lymph nodes up the back of the neck in trypanosoma brucei.
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How is trypanosoma brucei diagnosed?
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Finding trypomastigotes in blood and CSF
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Leishmaniasis enters the body via:
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Sand fly bite
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Cutaneous leishmaniasis has what symptom?
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Large characteristic lesion, prone to secondary infections.
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Visceral leishmaniasis has what symptom?
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Organ distension
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T. brucei is transmitted by:
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Tsetse fly
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What is the difference between cryptococcus neoformans and cryptosporidium?
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C. neoformans = fungal
Cryptosporidium = parasite |
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For which organism do you look for WORMS in stool instead of EGGS?
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Strongyloides stercoralis
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What eggs look very similar to hookworm eggs?
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Trichostrongylus
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What rhabditiform larvae look very similar to hookworm rhabditiform larvae?
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Strongyloides
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Which 2 organisms commonly cause autoreinfection?
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Enterobius vermicularis (scratch and re-swallow eggs)
Strongyoides (lay eggs in intestine, mature and hatch) |
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Which tapeworm autoreinfects?
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Hymenolepsis nana
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What specimen is used for Paragonimus westermani?
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Sputum and stool
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Which fluke is contracted from eating fish?
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Clonorchis sinensis
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Which 2 flukes are contracted from eating aquatic vegetation?
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Fasciola hepatica, Faciolopsis buski
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Which fluke is contracted from eating crabs/crayfish?
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Paragonimus westermani
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What two common protozoa are visually identical?
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Entamoeba histolytica and Entamoeba dispar
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What freshwater amoeba causes rapid death from encephalitis?
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Naegleria fowleri
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What amoeba has no cyst stage and is therefore very hard to ID?
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Dientamoeba fragilis
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Trypanosoma gambiense/rhodesiense causes what disease?
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African sleeping sickness
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Balantidium coli causes what serious condition?
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dysentary
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Babesia can be differentiated from Plasmodium by what key trait?
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Maltese cross pattern
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Toxoplasma gondii is intra or extracellular?
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Intra
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What amoeba causes pneumonia, especially in AIDS patients?
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Pneumocystis carinii
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Ascaris larvae migrate through the ___ and ___ before maturing in the large intestine.
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Lungs, Liver
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