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139 Cards in this Set
- Front
- Back
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What is the common name for Paragonimus westermanii? |
Oriental lung fluke |
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What is the common name for Schistosoma mansoni? |
Manson's blood fluke |
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What is the common name for Schistosoma japonicum? |
Blood fluke |
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What is the common name for Schistosoma haematobium? |
Bladder fluke |
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Helminths consists of which groups? |
Nematodes Cestodes Trematodes |
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What are nematodes? |
Roundworms |
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What are cestodes? |
Flatworms |
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What are trematodes? |
Flukes |
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What is the route of transmission for flukes? |
Direct ingestion of eggs Direct skin penetration Ingestion of larvae |
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What are the intermediate hosts for flukes? |
Snail Crab Fish |
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What is the infective stage of P. westermani? |
Metacercaria |
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What type of specimen is used to identify P. westermani? |
Sputum |
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What are the identifying features of the P. westermani egg? |
Flattened operculum Thick shell opposite operculum |
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What are the blood flukes? |
S. japonicum S. mansoni S. haematobium |
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What is the infective stage of Schistosoma? |
Cercariae |
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Which species is the causative agent of swimmer's itch? |
Schistosoma |
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What is swimmer's itch? |
Dermatitis due to infecting cercariae |
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What are the symptoms of swimmer's itch? |
Urticaria Fever Malaise |
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How is Schistosoma transmitted? |
Skin penetration from swimming in contaminated waters |
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What clinical manifestations are present from an infection of S. haematobium? |
Painful urination Hematuria Dysuria |
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What is the diagnostic stage of Schistosoma? |
Oval eggs with spines |
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Which Schistosoma species will be found in feces? |
S. japonicum S. mansoni |
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Which Schistosoma species will be found in urine? |
S. haematobium |
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What are the identifying features of the S. mansoni egg? |
Lateral spine No operculum |
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What are the identifying features of the S. japonicum egg? |
Small, curved spine No operculum |
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What are the identifying features of the S. haematobium egg? |
Terminal spine No operculum |
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What is the common name for Diphyllobothrium latum? |
Fish tapeworm |
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What is the common name for Taenia saginata? |
Beef tapeworm |
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What is the common name for Taenia solium? |
Pork tapeworm |
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What are proglottids? |
Segments added to tapeworms for their growth |
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What structure of tapeworms produce eggs? |
Proglottids |
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What is the infective stage of cestodes? |
Cysticercus |
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Tapeworm eggs have what features? |
Hexcanth embryo with three pairs of hooks |
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What is the infective stage of D. latum? |
Plerocercoid |
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Long-term infections with D. latum will result in what conditions? |
Vitamin B12 deficiency leading to megaloblastic anemia |
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D. latum proglottids have what features? |
Wide shape Rosette-shaped uterus |
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What are the identifying features of the D. latum egg? |
Indistinct operculum Knob opposite of operculum |
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What are the identifying features of the Taenia egg? |
Thick shell Radial striations |
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What feature is used to speciate Taenia? |
Proglottids |
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What is the common name for Enterobius vermicularis? |
Pinworm |
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What is the common name for Trichuris trichiura? |
Whipworm |
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What is the common name for Ascaris lumbricoides? |
Large intestinal roundworm |
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What is the common name for Necator americanus? |
New world hookworm |
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What is the common name for Stronglyoides stercoralis? |
Threadworm |
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What is the route of transmission for nematodes? |
Ingestion of egg Direct penetration of skin Insect vector |
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What is anal pruritus? |
Migration of the female worm to the perianal area |
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Which parasite causes anal pruritus? |
Enterobius vermicularis |
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How is E. vermicularis transmitted? |
Inhalation or ingestion of eggs Direct anal-oral transmission Autoinfection |
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What is the diagnostic method for E. vermicularis? |
Cellophane tape prep |
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What are the identifying features of the E. vermicularis egg? |
Flattened on one side C- shaped larva |
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How is T. trichuria transmitted? |
Soil Ingestion of egg |
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Which parasite presents as a co-infection with A. lumbricoides? |
Trichuris trichiura |
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Which parasite is capable of causing a hypochromic anemia in children? |
Trichuris trichiura |
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What are the identifying features of the T. trichiura egg? |
Barrel shaped, football shaped Hyaline polar plugs at each end |
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How is A. lumbricoides transmitted? |
Fecal-oral route |
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What are the identifying features of the fertile A. lumbricoides egg? |
Thick hyaline surrounding one stage cell embryo |
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What are the identifying features of the infertile A. lumbricoides egg? |
Elongated with mass of refractile granules |
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What are the symptoms of N. americanus infection? |
Ground itch Bronchitis Eosinophilia |
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What is the infective stage of N. americanus? |
Filariform larvae |
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What is diagnostic for N. americanus? |
Egg Rhabditiform larvae |
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What are the identifying features of the N. americanus egg? |
Thin shell 4-8 cell stage cleavage |
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Which parasite is capable of existing as a free-living worm? |
Stronglyoides stercoralis |
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What part of the body does S. stercoralis inhabit? |
Small intestine |
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What is the diagnostic stage of S. stercoralis? |
Rhabditiform larva |
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How is Trichinella spiralis transmitted? |
Ingestion of undercooked pork |
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What is the diagnostic stage of T. spiralis? |
Encapsulated coiled larva in striated muscle |
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Which parasite develops into cysts in striated muscle? |
Trichinella spiralis |
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What type of specimen is useful for identifying T. spiralis? |
Tissue biopsy |
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What preservatives are commonly used for recovery of parasites from stool samples? |
Polyvinyl alcohol 10% formalin |
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What methodologies are used for fecal samples preserved in 10% formalin? |
Immunoassay Direct wet mount |
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What methodologies are used for fecal samples preserved in polyvinyl alcohol? |
Stained smear DNA-PCR |
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Liquid stool will most likely contain which form of parasites? |
Trophozoite stage |
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Formed stools will most likely contain which form of parasites? |
Cyst |
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Soft stools will sometimes contain which form of parasites? |
Cyst |
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When should liquid and soft stool samples be examined? |
Within 30 minutes |
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When should formed stool samples be examined? |
Within 2-3 hours |
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What are the concentration techniques? |
Floatation Sedimentation |
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What is the principle of concentration techniques? |
Based on the difference in specific gravity between the parasites and edge concentrating solution |
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Why are concentration techniques performed? |
To concentrate parasites present in small volumes for easy detection |
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Which parasites will not be recovered using concentration techniques? |
Protozoan trophozoites |
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Concentration techniques will detect what organisms? |
Protozoan cysts Helminth larvae Helminth eggs |
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What happens during sedimentation methods? |
The organisms are concentrated in sediment at the bottom of the tube |
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What happens during floatation methods? |
The organisms are suspended at the top of a high-density fluid |
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What is the usual floatation procedure? |
Zinc sulfate method |
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Permanently stained smears are made to detect? |
Protozoan trophozoites and cysts |
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What are the most commonly used permanent stains? |
Trichrome stain Iron hematoxylin stain |
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What stains blue-green with a tinge of purple using the trichrome stain? |
Cytoplasm of protozoan cysts and trophozoites |
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What stains red or purple-red using the trichrome stain? |
Nuclear chromatin Ingested red blood cells Eggs and larva |
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What stains gray to black using the iron hematoxylin stain? |
Parasites |
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What stains black using the iron hematoxylin stain? |
Nuclear material |
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What is encystation? |
Transformation of cyst form to trophozoite form |
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What is the causative agent of amoebic dysentery? |
Entamoeba histolytica |
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What extraintestinal disease does E. histolytica cause? |
Liver abscesses |
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What feature is diagnostic for E. histolytica? |
Ingested red blood cells |
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What is the causative agent of primary amoebic meningoencephalitis? |
Naegleria fowleri |
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How is Naegleria fowleri transmitted? |
Swimming in contaminated waters |
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What body site does N. fowleri infect? |
Nasal mucosa |
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What is diagnostic for N. fowleri? |
Abundant neutrophils No bacteria Trophozoite in CSF |
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What type of specimen is used for identifying N. fowleri? |
CSF |
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What is the causative agent of granulomatous amoebic encephalitis? |
Acanthamoeba |
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How does Acanthamoeba cause keratitis? |
Swimming with contact lenses |
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What is the causative agent of giardiasis? |
Giardia lamblia |
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What is giardiasis? |
Inflammation of the intestinal mucosa |
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What is the most frequent parasite associated with gastroenteritis in the US? |
Giardia lamblia |
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Which parasite does not have a cyst form? |
Trichomonas vaginalis |
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What are the characteristics of T. vaginalis? |
Pear shaped Jerky motility |
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What is the causative agent of cystoisosporiasis? |
Cystoisospora belli |
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How is C. belli transmitted? |
Ingestion of infective oocyst in contaminated food and water |
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How are hemoflagellates transmitted? |
Insect vectors |
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What are the diagnostic stages of hemoflagellates that are found in humans? |
Trypomastigote Amastigote |
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What is a trypomastigote? |
Flagellated parasite found in blood, lymph or CSF |
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What is an amastigote? |
Obligate intracellular parasite found macrophages |
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What are hemoflagellates? |
Parasites that inhabit blood and tissues of humans |
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How is Leishmania transmitted? |
Sand flies |
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What is diagnostic for Leishmania? |
Amastigote inside macrophages and monocytes |
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How is Trypanosoma transmitted? |
Tsetse fly Reduviid bugs |
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What is the causative agent of chagas disease? |
Trypanosoma cruzi |
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What is diagnostic of Trypanosoma? |
Trypomastigote in blood and CSF |
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What is the ideal sample for malarial smears? |
Capillary blood |
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What stain will provide the best morphologic detail for blood parasites? |
Giemsa stain |
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What percentage of P. falciparum cases are diagnosed in the US? |
50% |
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How is Plasmodium transmitted? |
Anopheles mosquito |
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Which Plasmodium species causes the most severe cases? |
P. falciparum |
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What is the causative agent of Blackwater fever? |
Plasmodium falciparum |
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What is sexual reproduction of Plasmodium called? |
Sporogony |
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What is asexual reproduction of Plasmodium called? |
Schizogony |
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What happens during sporogony? |
Formation of oocysts containing sporozoites |
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What happens during schizogony? |
Merozoites produced by multiple fission |
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What is the earliest stage of Plasmodium in human infections? |
Ring-form trophozoite |
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Blood smears for Plasmodium will detect? |
Trophozoites Schizonts Gametocytes |
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What is the RBC morphology of P. vivax? |
Enlarged Schuffner's stippling |
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What is the RBC morphology of P. ovale? |
Oval Fringed edge |
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What is characteristic of the schizont for P. malariae? |
Daisy petal-like arrangement |
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Which Plasmodium species has the highest level of parasitemia? |
Plasmodium falciparum |
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What parasitic stages are seen in the peripheral blood for P. falciparum? |
Ring-form trophozoite Gametocyte |
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What is characteristic of the gametocyte for P. falciparum? |
Banana or crescent shape |
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How is Babesia transmitted? |
Tick bites of Ixodes species |
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What is the diagnostic for Babesia microti? |
Small, delicate ring-form trophozoite |
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What is characteristic of the trophozoite for B. microti? |
Maltese cross |
