Term
| What classification of protozoa are Plasmodium, Babesia, Toxoplasma and Cryptosporidium? |
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Definition
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Term
| What classification of protozoa is E. histolytica? |
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Definition
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Term
| What classification of protozoa are Giardia, Trichomonas, Leishmania, and Trypanosoma? |
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Definition
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Term
| Which two species of Plasmodium remain dormant in the liver? |
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Definition
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Term
| What phase of plasmodium do mosquitoes inject into humans? |
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Definition
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Term
| What is the first stage of plasmodium infection in humans? |
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Definition
| exoerythrocytic -- sporozoites develop into hepatic schizonts in liver parenchymal cells then become merozoites |
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Term
| What is the second stage of plasmodium infection in humans? |
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Definition
| erythrocytic -- merozoites infect rbcs (ring form) --> trophozoite --> RBC schizont --> merozoite or gametocyte |
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Term
| What species of plasmodium can cause very high levels of parasitemia? |
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Definition
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Term
| What organ systems does plasmodium affect and how? |
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Definition
| Cerebral malaria (mental status changes, seizures, coma), Pulmonary edema (acute lung injury), Renal failure (severe hemolysis = “Blackwater fever”, shock – ischemic insult to kidney) |
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Term
| What is the mechanism of transmission of Babesia microti? |
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Definition
| Ixodes scapularis tick introduces sporozoites into human host |
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Term
| What is the mechanism of diagnosing infection with Babesia microti? |
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Definition
| blood smear showing small rings or tetrads in rbcs |
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Term
| How is Toxoplasma gondii transmitted? |
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Definition
| Ingestion of cysts in meat or cat feces. It may also cross the placenta causing congenital toxoplasmosis. |
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Term
| What are the three clinical syndromes associated with Toxoplasma gondii? |
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Definition
1. fever/lymphadenopathy (mono-like illness)
2. encephalitis or myocarditis in the immunocompromised
3. congenital toxoplasmosis can cause CNS disease |
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Term
| How are the intestinal protozoa Giardia lamblia, E. histolytica and Cryptosporidium transmitted? |
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Definition
| ingestion of cysts in water |
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Term
| What organism would cause severe diarrhea in a person with AIDS? |
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Definition
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Term
| What organism would cause liver abscess in a Latino immigrant? |
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Definition
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Term
| What organism would cause cutaneous and oral/nasal/perineal mucosal ulcers in a Peruvian farmer? |
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Definition
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Term
| What organism would cause progressive encephalitis in a person from central Africa? |
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Definition
| Trypanosoma gambiense or rhodesiense |
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Term
| What organism would cause chronic heart failure in a Bolivian immigrant with normal coronary arteries? |
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Definition
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Term
| What is the vector for malaria? |
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Definition
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Term
| What is the vector for Babesiosis? |
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Definition
| Ixodes tick (same as Borrelia burgdorferi of Lyme Disease) |
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Term
| What is the vector for Leishmaniasis? |
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Definition
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Term
| What is the vector for African tripanosomiasis? |
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Definition
| Tsetse fly, a painful bite |
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Term
| What is the vector for American tripanosomiasis? |
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Definition
| Triatomid bug (Family Reduviidae) aka “kissing bug”, a painless bite |
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Term
| What is the intracellular form of hemoflagellates found in humans? |
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Definition
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Term
| What is the extracellular form of hemoflagellates found in the sandfly and also infects humans? |
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Definition
promastigote
-- causes L. tropica, L. braziliensis, and L. donovani |
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Term
| What is the extracellular form of hemoflagellates found in the tsetse fly or triatomid bug? |
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Definition
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Term
| What is the extracellular form of hemoflagellates found in the tsetse fly or triatomid bug and also infects humans? |
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Definition
trypomastigote
-- causes African and American Trypanosomiasis |
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Term
| What is another name for Nematodes? |
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Definition
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Term
| What is another name for Cestodes? |
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Definition
| tapeworms/segmented tapeworms |
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Term
| What are two other names for Trematodes? |
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Definition
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Term
| List the intestinal nematodes that migrate through the lung and cause pulmonary symptoms. |
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Definition
Strongyloides (acquired through skin)
Hookworm (ancylostoma and necator) (acquired through skin)
Ascaris (acquired by ingestion) |
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Term
| Name the one nematode and the one cestode that can complete their life cycles in the human and, through autoinfection, cause lifelong infection. |
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Definition
Nematode = Strongyloides
Cestode = Hymenolepsis nana |
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Term
| List the intestinal nematodes that remain in the intestine and do not migrate to the lung or other organs. |
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Definition
1. Enterobius vermicularis (pinworm) – ova ingested, develops in intestine. Female migrates to perianal region to deposit eggs. Can get retroinfection is ova hatches then goes back up into colon. Clinical: perianal itching, granuloma.
2. Trichuris trichirua (whipworm) – simple fecal-oral life cycle. Threadlike worm imbeds in mucosa. Clinical: dysentery, anemia, rectal prolapse. Unique lemon-shaped ova with polar plugs. |
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Term
| Describe the three clinical phases of trichinosis--intestinal, migration and recovery. |
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Definition
Phase I = Intestinal - 24-72 hours. Diarrhea, nausea, vomiting, abdominal pain due to ingestion of larvae encysted in undercooked pork
Phase II = Migration and Encystment - 7-42+ days. Fever, myalgia (skeletal muscle cells become ‘nurse’ cells); Headache, periorbital edema; Cough, dyspnea; Deaths (CNS or cardiac) occur during this stage w/ heavy infection; Inoculum dependent (>1000 larvae/gram of pork)
Phase III = Recovery |
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Term
| What organism would cause patient’s passing an earthworm-sized worm in a stool? |
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Definition
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Term
| What organism would cause microcytic anemia in a child from rural Bolivia who has helminth ova in the stool? |
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Definition
| Hookworm (ancylostoma and necator) |
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Term
| What organism would cause protracted perianal itching in two- and three-year-old siblings in Berwyn and indicate what test you would do to prove the diagnosis? |
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Definition
Enterobius vermicularis
Scotch-tape test |
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Term
| What organism would cause illness consisting of high fever, severe myalgias, perirobital edema and palpitations in a Polish immigrant who makes pork sausage at home? |
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Definition
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Term
| What organism would cause septicemia, severe diarrhea, pneumonia and eosinophilia in a young African person who was neutropenic after three cycles of chemotherapy for non-Hodgkin’s lymphoma? |
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Definition
| Strongyloides stercoralis |
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Term
| List the three tissue nematodes whose microfilariae circulate in the bloodstream of man. |
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Definition
Wuchereria bancrofti, Brugia malayi -- these both cause Lymphatic Filariasis
Loa Loa -- causes painful nodules and eyeworm |
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Term
| List four tapeworms that develop to adult stage in the human intestine. |
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Definition
| T. saginata, T. solium, D. latum, H. nana |
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Term
| Identify the cestode in which man, the definitive host may, after ingesting ova from another man’s feces, support larval development of the cestode resulting in cysts in the brain and other tissues |
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Definition
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Term
| Identify the food source for the following tapeworms: T. saginata, T. solium, D. latum |
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Definition
Taenia saginata = encysted beef
Taenia solium = encysted pork
Diphyllobothrium latum = encysted fish |
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Term
| Identify the test used to diagnose infection with the following tapeworms: T. saginata, T. solium, D. latum, H. nana. |
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Definition
| Stool sample analysis for ova or proglottids |
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Term
| Describe the mechanism of transmission in echinococcal disease. |
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Definition
| E. granulosus is a dog tapeworm in which sheep are the usual intermediate host. Man, when closely involved with dogs and sheep, may accidentally ingest egg from dog feces and become intermediate host. Ova become larvae in SI. The cyst in man develops a germinal layer from which multiple daughter cysts develop. Cysts develop in liver (2/3), brain, lung, bone. |
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Term
| Describe the mechanism by which the three schistosome species infect humans. |
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Definition
S. mansoni and S. japonicum infected by free swimming form of fluke called a cercariae. These migrate down mesenteric venules and deposit in SI or colon.
S. haematobium also infects through a free swimming cercariae but migrates to the bladder |
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Term
| Describe the mechanism by which the three schistosome species cause disease in the liver and urinary tract. |
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Definition
S. mansoni and S. japonicum can cause Katayama Fever--acute fever, cough, lymphadenopathy, hepatosplenomegaly. Chronic infection can lead to periportal fibrosis and portal hypertension. Mansoni = myelopathy.
S. haematobium causes chronically contracted bladder and severe urinary symptoms --urinary fibrosis and obstructive uropathy. |
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Term
| What animal serves as the intermediate host for the three schistosomes? |
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Definition
| snail (Ova passed in stool and release into miracidium which infects snails) |
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Term
| Identify the mechanism by which man acquires an infection with Opisthorchis species, the biliary fluke. |
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Definition
| ingestion of metacercariae in infested fish |
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Term
| Identify the mechanism by which man acquires an infection with Paragonimus westermani, the lung fluke. |
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Definition
| ingestion of metacercariae in infested crayfish/crab |
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Term
| Explain why treatment of asymptomatic infection with Trichuris trichiura in a traveler who has returned to the U.S. from Cambodia might not be necessary. |
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Definition
| Trichuris trichiura doesn’t multiply in a person and adults die off. |
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Term
| Name the nematodes that are acquired through skin penetration and migrate through the lung. |
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Definition
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Term
| Name the nematodes that are acquired by ingestion and migrate through the lung. |
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Definition
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Term
| Name the nematode that can autoinfect (reinfect) the human intestine, complete its life cycle and thus cause lifelong infection without acquiring new organisms from the environment. |
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Definition
| Strongyloides stercolaris |
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Term
The clinical parasitology laboratory identifies infection with Strongyloides
stercoralis by..? |
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Definition
| visualizing Rhabditiform larvae in the stool specimen |
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Term
| Explain why treatment of infection with Strongyloides is mandatory. |
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Definition
| Due to autoinfection, strongyloides is a chronic infection. |
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Term
| The major clinical manifestation in persons with moderate to heavy infection with hookworm is .. |
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Definition
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|
Term
| The morphologic feature which contributes most to symptoms caused by Ascaris lumbricoides is .. |
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Definition
| its large size, which contributes to intestinal and biliary obstruction |
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Term
| How does visceral larva migrans basically differ from infection with other intestinal nematodes? |
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Definition
| Man is an accidental host of dog, cat or raccoon ascarid. |
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Term
| Specimens for diagnosis of infection with Enterobius vermicularis are best obtained by ... |
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Definition
| sticking scotch tape (or pinworm collector) to perianal area in the morning and looking for ova in the specimen. |
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Term
| Oval shaped ova with two plugs look like the end of a lemon is characteristic of which intestinal nematode? |
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Definition
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Term
Name the parasite acquired by eating undercooked, infested pork which causes
myositis, cardiac conduction defects and encephalitis in heavily infected patients. |
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Definition
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Term
| Which nematode is associated with a snail intermediate host and eosinophilic meningitis? |
|
Definition
| Angiostrongylus cantonensis |
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Term
| Name three filaria species in which microfilaria circulate in the blood |
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Definition
| Wuchereria bancrofti, Brugia malayi, Loa Loa |
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|
Term
| The vector of the filaria infection which causes chronic lymphedema is the .. |
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Definition
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Term
| Which filaria species can cause chronic lymphedema? |
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Definition
| Wuchereria bancrofri, Brugia malayi |
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Term
| What symbiotic bacteria is associated with Wuchereria bancrofri, Brugia malayi and Onchocerca volvulus? |
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Definition
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|
Term
| Which form (adult or microfilaria) of Onchocerca volvulus causes damage to subcutaneous supporting tissues and the eye? |
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Definition
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Term
| How do humans acquire infection with Dracunculus medinensis (Guinea Worm)? |
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Definition
| Step in wells with pump -- humans ingest larvae-containing copepods in water. Larvae released in SI and travel to lower extremities where they become adults and form blisters. Larvae are released from blister fluid into step wells where copepods ingest them again. |
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Term
| Which of the human intestinal tapeworms can encyst in the extraintestinal tissues of man if its ova are ingested? |
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Definition
| Taenia solium (pork tapeworm) causes Cysticercosis – muscle, breast, eye, brain (neurocysticerosis is the major clinical presentation). |
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Term
| Which tapeworm may cause macrocytic anemia? |
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Definition
| Diphyllobothrium latum competes with host for B12 |
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Term
| Which tapeworm can complete its life cycle in the intestine of man and thus multiply into many tapeworms? |
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Definition
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|
Term
| What is the most common clinical manifestations in man if disease results from ingestion of ova from the dog tapeworm (Echinococcus granulosus)? |
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Definition
| Space occupying cysts: liver*, lung, bone, kidney. |
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Term
| Schistosomiasis (other than swimmers' itch) does not occur in the U.S. because .. |
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Definition
| We don’t have the right type of snails (miracidia) |
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|
Term
| Which schistosome species cause chronic portal hypertension? |
|
Definition
| S. mansoni and S. japonicum |
|
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Term
| What morphologic form of the schistosome fluke causes chronic inflammatory portal hypertension? |
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Definition
| EGGS of S. mansoni and S. japonicum which do not escape in feces are carried back to liver where they produce an intense granulomatous fibrotic reaction. This eventually leads to portal hypertension. |
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Term
| What morphologic form of the schistosome fluke penetrates the skin establishing infection in man? |
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Definition
| Free-swimming cercariae (LARVAE) of S. haematobium enter skin. Adults migrate to bladder causing chronically contracted bladder and severe urinary symptoms. |
|
|
Term
| How does one diagnose infection with Schistosoma haematobium? |
|
Definition
| Characteristic ova in urine, rectal biopsy crush preparation, serology |
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Term
| Ova with a little triangular foot is characteristic of what helminth? |
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Definition
|
|
Term
| Man acquires infection with Opisthorchis sinensis by .. |
|
Definition
| Ingestion of uncooked fish that are metacercariae-infested |
|
|
Term
| The major site of disease in persons infected with Paragonimus westermani is the .. |
|
Definition
LUNG
cough, hemoptysis --> chronic pneumonia, lung abscess, empyema |
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